/* Common target dependent code for GDB on ARM systems. Copyright (C) 1988-2023 Free Software Foundation, Inc. This file is part of GDB. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see . */ #include "defs.h" #include /* XXX for isupper (). */ #include "frame.h" #include "language.h" #include "inferior.h" #include "infrun.h" #include "gdbcmd.h" #include "gdbcore.h" #include "dis-asm.h" /* For register styles. */ #include "disasm.h" #include "regcache.h" #include "reggroups.h" #include "target-float.h" #include "value.h" #include "arch-utils.h" #include "osabi.h" #include "frame-unwind.h" #include "frame-base.h" #include "trad-frame.h" #include "objfiles.h" #include "dwarf2.h" #include "dwarf2/frame.h" #include "gdbtypes.h" #include "prologue-value.h" #include "remote.h" #include "target-descriptions.h" #include "user-regs.h" #include "observable.h" #include "count-one-bits.h" #include "arch/arm.h" #include "arch/arm-get-next-pcs.h" #include "arm-tdep.h" #include "sim/sim-arm.h" #include "elf-bfd.h" #include "coff/internal.h" #include "elf/arm.h" #include "record.h" #include "record-full.h" #include #include "producer.h" #if GDB_SELF_TEST #include "gdbsupport/selftest.h" #endif static bool arm_debug; /* Print an "arm" debug statement. */ #define arm_debug_printf(fmt, ...) \ debug_prefixed_printf_cond (arm_debug, "arm", fmt, ##__VA_ARGS__) /* Macros for setting and testing a bit in a minimal symbol that marks it as Thumb function. The MSB of the minimal symbol's "info" field is used for this purpose. MSYMBOL_SET_SPECIAL Actually sets the "special" bit. MSYMBOL_IS_SPECIAL Tests the "special" bit in a minimal symbol. */ #define MSYMBOL_SET_SPECIAL(msym) \ (msym)->set_target_flag_1 (true) #define MSYMBOL_IS_SPECIAL(msym) \ (msym)->target_flag_1 () struct arm_mapping_symbol { CORE_ADDR value; char type; bool operator< (const arm_mapping_symbol &other) const { return this->value < other.value; } }; typedef std::vector arm_mapping_symbol_vec; struct arm_per_bfd { explicit arm_per_bfd (size_t num_sections) : section_maps (new arm_mapping_symbol_vec[num_sections]), section_maps_sorted (new bool[num_sections] ()) {} DISABLE_COPY_AND_ASSIGN (arm_per_bfd); /* Information about mapping symbols ($a, $d, $t) in the objfile. The format is an array of vectors of arm_mapping_symbols, there is one vector for each section of the objfile (the array is index by BFD section index). For each section, the vector of arm_mapping_symbol is sorted by symbol value (address). */ std::unique_ptr section_maps; /* For each corresponding element of section_maps above, is this vector sorted. */ std::unique_ptr section_maps_sorted; }; /* Per-bfd data used for mapping symbols. */ static const registry::key arm_bfd_data_key; /* The list of available "set arm ..." and "show arm ..." commands. */ static struct cmd_list_element *setarmcmdlist = NULL; static struct cmd_list_element *showarmcmdlist = NULL; /* The type of floating-point to use. Keep this in sync with enum arm_float_model, and the help string in _initialize_arm_tdep. */ static const char *const fp_model_strings[] = { "auto", "softfpa", "fpa", "softvfp", "vfp", NULL }; /* A variable that can be configured by the user. */ static enum arm_float_model arm_fp_model = ARM_FLOAT_AUTO; static const char *current_fp_model = "auto"; /* The ABI to use. Keep this in sync with arm_abi_kind. */ static const char *const arm_abi_strings[] = { "auto", "APCS", "AAPCS", NULL }; /* A variable that can be configured by the user. */ static enum arm_abi_kind arm_abi_global = ARM_ABI_AUTO; static const char *arm_abi_string = "auto"; /* The execution mode to assume. */ static const char *const arm_mode_strings[] = { "auto", "arm", "thumb", NULL }; static const char *arm_fallback_mode_string = "auto"; static const char *arm_force_mode_string = "auto"; /* The standard register names, and all the valid aliases for them. Note that `fp', `sp' and `pc' are not added in this alias list, because they have been added as builtin user registers in std-regs.c:_initialize_frame_reg. */ static const struct { const char *name; int regnum; } arm_register_aliases[] = { /* Basic register numbers. */ { "r0", 0 }, { "r1", 1 }, { "r2", 2 }, { "r3", 3 }, { "r4", 4 }, { "r5", 5 }, { "r6", 6 }, { "r7", 7 }, { "r8", 8 }, { "r9", 9 }, { "r10", 10 }, { "r11", 11 }, { "r12", 12 }, { "r13", 13 }, { "r14", 14 }, { "r15", 15 }, /* Synonyms (argument and variable registers). */ { "a1", 0 }, { "a2", 1 }, { "a3", 2 }, { "a4", 3 }, { "v1", 4 }, { "v2", 5 }, { "v3", 6 }, { "v4", 7 }, { "v5", 8 }, { "v6", 9 }, { "v7", 10 }, { "v8", 11 }, /* Other platform-specific names for r9. */ { "sb", 9 }, { "tr", 9 }, /* Special names. */ { "ip", 12 }, { "lr", 14 }, /* Names used by GCC (not listed in the ARM EABI). */ { "sl", 10 }, /* A special name from the older ATPCS. */ { "wr", 7 }, }; static const char *const arm_register_names[] = {"r0", "r1", "r2", "r3", /* 0 1 2 3 */ "r4", "r5", "r6", "r7", /* 4 5 6 7 */ "r8", "r9", "r10", "r11", /* 8 9 10 11 */ "r12", "sp", "lr", "pc", /* 12 13 14 15 */ "f0", "f1", "f2", "f3", /* 16 17 18 19 */ "f4", "f5", "f6", "f7", /* 20 21 22 23 */ "fps", "cpsr" }; /* 24 25 */ /* Holds the current set of options to be passed to the disassembler. */ static char *arm_disassembler_options; /* Valid register name styles. */ static const char **valid_disassembly_styles; /* Disassembly style to use. Default to "std" register names. */ static const char *disassembly_style; /* All possible arm target descriptors. */ static struct target_desc *tdesc_arm_list[ARM_FP_TYPE_INVALID][2]; static struct target_desc *tdesc_arm_mprofile_list[ARM_M_TYPE_INVALID]; /* This is used to keep the bfd arch_info in sync with the disassembly style. */ static void set_disassembly_style_sfunc (const char *, int, struct cmd_list_element *); static void show_disassembly_style_sfunc (struct ui_file *, int, struct cmd_list_element *, const char *); static enum register_status arm_neon_quad_read (struct gdbarch *gdbarch, readable_regcache *regcache, int regnum, gdb_byte *buf); static void arm_neon_quad_write (struct gdbarch *gdbarch, struct regcache *regcache, int regnum, const gdb_byte *buf); static CORE_ADDR arm_get_next_pcs_syscall_next_pc (struct arm_get_next_pcs *self); /* get_next_pcs operations. */ static struct arm_get_next_pcs_ops arm_get_next_pcs_ops = { arm_get_next_pcs_read_memory_unsigned_integer, arm_get_next_pcs_syscall_next_pc, arm_get_next_pcs_addr_bits_remove, arm_get_next_pcs_is_thumb, NULL, }; struct arm_prologue_cache { /* The stack pointer at the time this frame was created; i.e. the caller's stack pointer when this function was called. It is used to identify this frame. */ CORE_ADDR sp; /* Additional stack pointers used by M-profile with Security extension. */ /* Use msp_s / psp_s to hold the values of msp / psp when there is no Security extension. */ CORE_ADDR msp_s; CORE_ADDR msp_ns; CORE_ADDR psp_s; CORE_ADDR psp_ns; /* Active stack pointer. */ int active_sp_regnum; int active_msp_regnum; int active_psp_regnum; /* The frame base for this frame is just prev_sp - frame size. FRAMESIZE is the distance from the frame pointer to the initial stack pointer. */ int framesize; /* The register used to hold the frame pointer for this frame. */ int framereg; /* True if the return address is signed, false otherwise. */ gdb::optional ra_signed_state; /* Saved register offsets. */ trad_frame_saved_reg *saved_regs; arm_prologue_cache() = default; }; /* Reconstruct T bit in program status register from LR value. */ static inline ULONGEST reconstruct_t_bit(struct gdbarch *gdbarch, CORE_ADDR lr, ULONGEST psr) { ULONGEST t_bit = arm_psr_thumb_bit (gdbarch); if (IS_THUMB_ADDR (lr)) psr |= t_bit; else psr &= ~t_bit; return psr; } /* Initialize CACHE fields for which zero is not adequate (CACHE is expected to have been ZALLOC'ed before calling this function). */ static void arm_cache_init (struct arm_prologue_cache *cache, struct gdbarch *gdbarch) { cache->active_sp_regnum = ARM_SP_REGNUM; cache->saved_regs = trad_frame_alloc_saved_regs (gdbarch); } /* Similar to the previous function, but extracts GDBARCH from FRAME. */ static void arm_cache_init (struct arm_prologue_cache *cache, frame_info_ptr frame) { struct gdbarch *gdbarch = get_frame_arch (frame); arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); arm_cache_init (cache, gdbarch); cache->sp = get_frame_register_unsigned (frame, ARM_SP_REGNUM); if (tdep->have_sec_ext) { const CORE_ADDR msp_val = get_frame_register_unsigned (frame, tdep->m_profile_msp_regnum); const CORE_ADDR psp_val = get_frame_register_unsigned (frame, tdep->m_profile_psp_regnum); cache->msp_s = get_frame_register_unsigned (frame, tdep->m_profile_msp_s_regnum); cache->msp_ns = get_frame_register_unsigned (frame, tdep->m_profile_msp_ns_regnum); cache->psp_s = get_frame_register_unsigned (frame, tdep->m_profile_psp_s_regnum); cache->psp_ns = get_frame_register_unsigned (frame, tdep->m_profile_psp_ns_regnum); /* Identify what msp is alias for (msp_s or msp_ns). */ if (msp_val == cache->msp_s) cache->active_msp_regnum = tdep->m_profile_msp_s_regnum; else if (msp_val == cache->msp_ns) cache->active_msp_regnum = tdep->m_profile_msp_ns_regnum; else { warning (_("Invalid state, unable to determine msp alias, assuming " "msp_s.")); cache->active_msp_regnum = tdep->m_profile_msp_s_regnum; } /* Identify what psp is alias for (psp_s or psp_ns). */ if (psp_val == cache->psp_s) cache->active_psp_regnum = tdep->m_profile_psp_s_regnum; else if (psp_val == cache->psp_ns) cache->active_psp_regnum = tdep->m_profile_psp_ns_regnum; else { warning (_("Invalid state, unable to determine psp alias, assuming " "psp_s.")); cache->active_psp_regnum = tdep->m_profile_psp_s_regnum; } /* Identify what sp is alias for (msp_s, msp_ns, psp_s or psp_ns). */ if (msp_val == cache->sp) cache->active_sp_regnum = cache->active_msp_regnum; else if (psp_val == cache->sp) cache->active_sp_regnum = cache->active_psp_regnum; else { warning (_("Invalid state, unable to determine sp alias, assuming " "msp.")); cache->active_sp_regnum = cache->active_msp_regnum; } } else if (tdep->is_m) { cache->msp_s = get_frame_register_unsigned (frame, tdep->m_profile_msp_regnum); cache->psp_s = get_frame_register_unsigned (frame, tdep->m_profile_psp_regnum); /* Identify what sp is alias for (msp or psp). */ if (cache->msp_s == cache->sp) cache->active_sp_regnum = tdep->m_profile_msp_regnum; else if (cache->psp_s == cache->sp) cache->active_sp_regnum = tdep->m_profile_psp_regnum; else { warning (_("Invalid state, unable to determine sp alias, assuming " "msp.")); cache->active_sp_regnum = tdep->m_profile_msp_regnum; } } else { cache->msp_s = get_frame_register_unsigned (frame, ARM_SP_REGNUM); cache->active_sp_regnum = ARM_SP_REGNUM; } } /* Return the requested stack pointer value (in REGNUM), taking into account whether we have a Security extension or an M-profile CPU. */ static CORE_ADDR arm_cache_get_sp_register (struct arm_prologue_cache *cache, arm_gdbarch_tdep *tdep, int regnum) { if (tdep->have_sec_ext) { if (regnum == tdep->m_profile_msp_s_regnum) return cache->msp_s; if (regnum == tdep->m_profile_msp_ns_regnum) return cache->msp_ns; if (regnum == tdep->m_profile_psp_s_regnum) return cache->psp_s; if (regnum == tdep->m_profile_psp_ns_regnum) return cache->psp_ns; if (regnum == tdep->m_profile_msp_regnum) return arm_cache_get_sp_register (cache, tdep, cache->active_msp_regnum); if (regnum == tdep->m_profile_psp_regnum) return arm_cache_get_sp_register (cache, tdep, cache->active_psp_regnum); if (regnum == ARM_SP_REGNUM) return arm_cache_get_sp_register (cache, tdep, cache->active_sp_regnum); } else if (tdep->is_m) { if (regnum == tdep->m_profile_msp_regnum) return cache->msp_s; if (regnum == tdep->m_profile_psp_regnum) return cache->psp_s; if (regnum == ARM_SP_REGNUM) return arm_cache_get_sp_register (cache, tdep, cache->active_sp_regnum); } else if (regnum == ARM_SP_REGNUM) return cache->sp; gdb_assert_not_reached ("Invalid SP selection"); } /* Return the previous stack address, depending on which SP register is active. */ static CORE_ADDR arm_cache_get_prev_sp_value (struct arm_prologue_cache *cache, arm_gdbarch_tdep *tdep) { CORE_ADDR val = arm_cache_get_sp_register (cache, tdep, cache->active_sp_regnum); return val; } /* Set the active stack pointer to VAL. */ static void arm_cache_set_active_sp_value (struct arm_prologue_cache *cache, arm_gdbarch_tdep *tdep, CORE_ADDR val) { if (tdep->have_sec_ext) { if (cache->active_sp_regnum == tdep->m_profile_msp_s_regnum) cache->msp_s = val; else if (cache->active_sp_regnum == tdep->m_profile_msp_ns_regnum) cache->msp_ns = val; else if (cache->active_sp_regnum == tdep->m_profile_psp_s_regnum) cache->psp_s = val; else if (cache->active_sp_regnum == tdep->m_profile_psp_ns_regnum) cache->psp_ns = val; return; } else if (tdep->is_m) { if (cache->active_sp_regnum == tdep->m_profile_msp_regnum) cache->msp_s = val; else if (cache->active_sp_regnum == tdep->m_profile_psp_regnum) cache->psp_s = val; return; } else if (cache->active_sp_regnum == ARM_SP_REGNUM) { cache->sp = val; return; } gdb_assert_not_reached ("Invalid SP selection"); } /* Return true if REGNUM is one of the alternative stack pointers. */ static bool arm_is_alternative_sp_register (arm_gdbarch_tdep *tdep, int regnum) { if ((regnum == tdep->m_profile_msp_regnum) || (regnum == tdep->m_profile_msp_s_regnum) || (regnum == tdep->m_profile_msp_ns_regnum) || (regnum == tdep->m_profile_psp_regnum) || (regnum == tdep->m_profile_psp_s_regnum) || (regnum == tdep->m_profile_psp_ns_regnum)) return true; else return false; } /* Set the active stack pointer to SP_REGNUM. */ static void arm_cache_switch_prev_sp (struct arm_prologue_cache *cache, arm_gdbarch_tdep *tdep, int sp_regnum) { gdb_assert (arm_is_alternative_sp_register (tdep, sp_regnum)); if (tdep->have_sec_ext) { gdb_assert (sp_regnum != tdep->m_profile_msp_regnum && sp_regnum != tdep->m_profile_psp_regnum); if (sp_regnum == tdep->m_profile_msp_s_regnum || sp_regnum == tdep->m_profile_psp_s_regnum) { cache->active_msp_regnum = tdep->m_profile_msp_s_regnum; cache->active_psp_regnum = tdep->m_profile_psp_s_regnum; } else if (sp_regnum == tdep->m_profile_msp_ns_regnum || sp_regnum == tdep->m_profile_psp_ns_regnum) { cache->active_msp_regnum = tdep->m_profile_msp_ns_regnum; cache->active_psp_regnum = tdep->m_profile_psp_ns_regnum; } } cache->active_sp_regnum = sp_regnum; } namespace { /* Abstract class to read ARM instructions from memory. */ class arm_instruction_reader { public: /* Read a 4 bytes instruction from memory using the BYTE_ORDER endianness. */ virtual uint32_t read (CORE_ADDR memaddr, bfd_endian byte_order) const = 0; }; /* Read instructions from target memory. */ class target_arm_instruction_reader : public arm_instruction_reader { public: uint32_t read (CORE_ADDR memaddr, bfd_endian byte_order) const override { return read_code_unsigned_integer (memaddr, 4, byte_order); } }; } /* namespace */ static CORE_ADDR arm_analyze_prologue (struct gdbarch *gdbarch, CORE_ADDR prologue_start, CORE_ADDR prologue_end, struct arm_prologue_cache *cache, const arm_instruction_reader &insn_reader); /* Architecture version for displaced stepping. This effects the behaviour of certain instructions, and really should not be hard-wired. */ #define DISPLACED_STEPPING_ARCH_VERSION 5 /* See arm-tdep.h. */ bool arm_apcs_32 = true; bool arm_unwind_secure_frames = true; /* Return the bit mask in ARM_PS_REGNUM that indicates Thumb mode. */ int arm_psr_thumb_bit (struct gdbarch *gdbarch) { arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); if (tdep->is_m) return XPSR_T; else return CPSR_T; } /* Determine if the processor is currently executing in Thumb mode. */ int arm_is_thumb (struct regcache *regcache) { ULONGEST cpsr; ULONGEST t_bit = arm_psr_thumb_bit (regcache->arch ()); cpsr = regcache_raw_get_unsigned (regcache, ARM_PS_REGNUM); return (cpsr & t_bit) != 0; } /* Determine if FRAME is executing in Thumb mode. FRAME must be an ARM frame. */ int arm_frame_is_thumb (frame_info_ptr frame) { /* Check the architecture of FRAME. */ struct gdbarch *gdbarch = get_frame_arch (frame); gdb_assert (gdbarch_bfd_arch_info (gdbarch)->arch == bfd_arch_arm); /* Every ARM frame unwinder can unwind the T bit of the CPSR, either directly (from a signal frame or dummy frame) or by interpreting the saved LR (from a prologue or DWARF frame). So consult it and trust the unwinders. */ CORE_ADDR cpsr = get_frame_register_unsigned (frame, ARM_PS_REGNUM); /* Find and extract the thumb bit. */ ULONGEST t_bit = arm_psr_thumb_bit (gdbarch); return (cpsr & t_bit) != 0; } /* Search for the mapping symbol covering MEMADDR. If one is found, return its type. Otherwise, return 0. If START is non-NULL, set *START to the location of the mapping symbol. */ static char arm_find_mapping_symbol (CORE_ADDR memaddr, CORE_ADDR *start) { struct obj_section *sec; /* If there are mapping symbols, consult them. */ sec = find_pc_section (memaddr); if (sec != NULL) { arm_per_bfd *data = arm_bfd_data_key.get (sec->objfile->obfd.get ()); if (data != NULL) { unsigned int section_idx = sec->the_bfd_section->index; arm_mapping_symbol_vec &map = data->section_maps[section_idx]; /* Sort the vector on first use. */ if (!data->section_maps_sorted[section_idx]) { std::sort (map.begin (), map.end ()); data->section_maps_sorted[section_idx] = true; } arm_mapping_symbol map_key = { memaddr - sec->addr (), 0 }; arm_mapping_symbol_vec::const_iterator it = std::lower_bound (map.begin (), map.end (), map_key); /* std::lower_bound finds the earliest ordered insertion point. If the symbol at this position starts at this exact address, we use that; otherwise, the preceding mapping symbol covers this address. */ if (it < map.end ()) { if (it->value == map_key.value) { if (start) *start = it->value + sec->addr (); return it->type; } } if (it > map.begin ()) { arm_mapping_symbol_vec::const_iterator prev_it = it - 1; if (start) *start = prev_it->value + sec->addr (); return prev_it->type; } } } return 0; } /* Determine if the program counter specified in MEMADDR is in a Thumb function. This function should be called for addresses unrelated to any executing frame; otherwise, prefer arm_frame_is_thumb. */ int arm_pc_is_thumb (struct gdbarch *gdbarch, CORE_ADDR memaddr) { struct bound_minimal_symbol sym; char type; arm_displaced_step_copy_insn_closure *dsc = nullptr; arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); if (gdbarch_displaced_step_copy_insn_closure_by_addr_p (gdbarch)) dsc = ((arm_displaced_step_copy_insn_closure * ) gdbarch_displaced_step_copy_insn_closure_by_addr (gdbarch, current_inferior (), memaddr)); /* If checking the mode of displaced instruction in copy area, the mode should be determined by instruction on the original address. */ if (dsc) { displaced_debug_printf ("check mode of %.8lx instead of %.8lx", (unsigned long) dsc->insn_addr, (unsigned long) memaddr); memaddr = dsc->insn_addr; } /* If bit 0 of the address is set, assume this is a Thumb address. */ if (IS_THUMB_ADDR (memaddr)) return 1; /* If the user wants to override the symbol table, let him. */ if (strcmp (arm_force_mode_string, "arm") == 0) return 0; if (strcmp (arm_force_mode_string, "thumb") == 0) return 1; /* ARM v6-M and v7-M are always in Thumb mode. */ if (tdep->is_m) return 1; /* If there are mapping symbols, consult them. */ type = arm_find_mapping_symbol (memaddr, NULL); if (type) return type == 't'; /* Thumb functions have a "special" bit set in minimal symbols. */ sym = lookup_minimal_symbol_by_pc (memaddr); if (sym.minsym) return (MSYMBOL_IS_SPECIAL (sym.minsym)); /* If the user wants to override the fallback mode, let them. */ if (strcmp (arm_fallback_mode_string, "arm") == 0) return 0; if (strcmp (arm_fallback_mode_string, "thumb") == 0) return 1; /* If we couldn't find any symbol, but we're talking to a running target, then trust the current value of $cpsr. This lets "display/i $pc" always show the correct mode (though if there is a symbol table we will not reach here, so it still may not be displayed in the mode it will be executed). */ if (target_has_registers ()) return arm_frame_is_thumb (get_current_frame ()); /* Otherwise we're out of luck; we assume ARM. */ return 0; } static inline bool arm_m_addr_is_lockup (CORE_ADDR addr) { switch (addr) { /* Values for lockup state. For more details see "B1.5.15 Unrecoverable exception cases" in both ARMv6-M and ARMv7-M Architecture Reference Manuals, or see "B4.32 Lockup" in ARMv8-M Architecture Reference Manual. */ case 0xeffffffe: case 0xfffffffe: case 0xffffffff: return true; default: /* Address is not lockup. */ return false; } } /* Determine if the address specified equals any of these magic return values, called EXC_RETURN, defined by the ARM v6-M, v7-M and v8-M architectures. Also include lockup magic PC value. Check also for FNC_RETURN if we have the v8-M security extension. From ARMv6-M Reference Manual B1.5.8 Table B1-5 Exception return behavior EXC_RETURN Return To Return Stack 0xFFFFFFF1 Handler mode Main 0xFFFFFFF9 Thread mode Main 0xFFFFFFFD Thread mode Process From ARMv7-M Reference Manual B1.5.8 Table B1-8 EXC_RETURN definition of exception return behavior, no FP EXC_RETURN Return To Return Stack 0xFFFFFFF1 Handler mode Main 0xFFFFFFF9 Thread mode Main 0xFFFFFFFD Thread mode Process Table B1-9 EXC_RETURN definition of exception return behavior, with FP EXC_RETURN Return To Return Stack Frame Type 0xFFFFFFE1 Handler mode Main Extended 0xFFFFFFE9 Thread mode Main Extended 0xFFFFFFED Thread mode Process Extended 0xFFFFFFF1 Handler mode Main Basic 0xFFFFFFF9 Thread mode Main Basic 0xFFFFFFFD Thread mode Process Basic For more details see "B1.5.8 Exception return behavior" in both ARMv6-M and ARMv7-M Architecture Reference Manuals. From ARMv8-M Architecture Technical Reference, D1.2.95 FType, Mode and SPSEL bits are to be considered when the Security Extension is not implemented. EXC_RETURN Return To Return Stack Frame Type 0xFFFFFFA0 Handler mode Main Extended 0xFFFFFFA8 Thread mode Main Extended 0xFFFFFFAC Thread mode Process Extended 0xFFFFFFB0 Handler mode Main Standard 0xFFFFFFB8 Thread mode Main Standard 0xFFFFFFBC Thread mode Process Standard */ static int arm_m_addr_is_magic (struct gdbarch *gdbarch, CORE_ADDR addr) { if (arm_m_addr_is_lockup (addr)) return 1; arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); if (tdep->have_sec_ext) { switch ((addr & 0xff000000)) { case 0xff000000: /* EXC_RETURN pattern. */ case 0xfe000000: /* FNC_RETURN pattern. */ return 1; default: return 0; } } else { switch (addr) { /* Values from ARMv8-M Architecture Technical Reference. */ case 0xffffffa0: case 0xffffffa8: case 0xffffffac: case 0xffffffb0: case 0xffffffb8: case 0xffffffbc: /* Values from Tables in B1.5.8 the EXC_RETURN definitions of the exception return behavior. */ case 0xffffffe1: case 0xffffffe9: case 0xffffffed: case 0xfffffff1: case 0xfffffff9: case 0xfffffffd: /* Address is magic. */ return 1; default: /* Address is not magic. */ return 0; } } } /* Remove useless bits from addresses in a running program. */ static CORE_ADDR arm_addr_bits_remove (struct gdbarch *gdbarch, CORE_ADDR val) { arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); /* On M-profile devices, do not strip the low bit from EXC_RETURN (the magic exception return address). */ if (tdep->is_m && arm_m_addr_is_magic (gdbarch, val)) return val; if (arm_apcs_32) return UNMAKE_THUMB_ADDR (val); else return (val & 0x03fffffc); } /* Return 1 if PC is the start of a compiler helper function which can be safely ignored during prologue skipping. IS_THUMB is true if the function is known to be a Thumb function due to the way it is being called. */ static int skip_prologue_function (struct gdbarch *gdbarch, CORE_ADDR pc, int is_thumb) { enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch); struct bound_minimal_symbol msym; msym = lookup_minimal_symbol_by_pc (pc); if (msym.minsym != NULL && msym.value_address () == pc && msym.minsym->linkage_name () != NULL) { const char *name = msym.minsym->linkage_name (); /* The GNU linker's Thumb call stub to foo is named __foo_from_thumb. */ if (strstr (name, "_from_thumb") != NULL) name += 2; /* On soft-float targets, __truncdfsf2 is called to convert promoted arguments to their argument types in non-prototyped functions. */ if (startswith (name, "__truncdfsf2")) return 1; if (startswith (name, "__aeabi_d2f")) return 1; /* Internal functions related to thread-local storage. */ if (startswith (name, "__tls_get_addr")) return 1; if (startswith (name, "__aeabi_read_tp")) return 1; } else { /* If we run against a stripped glibc, we may be unable to identify special functions by name. Check for one important case, __aeabi_read_tp, by comparing the *code* against the default implementation (this is hand-written ARM assembler in glibc). */ if (!is_thumb && read_code_unsigned_integer (pc, 4, byte_order_for_code) == 0xe3e00a0f /* mov r0, #0xffff0fff */ && read_code_unsigned_integer (pc + 4, 4, byte_order_for_code) == 0xe240f01f) /* sub pc, r0, #31 */ return 1; } return 0; } /* Extract the immediate from instruction movw/movt of encoding T. INSN1 is the first 16-bit of instruction, and INSN2 is the second 16-bit of instruction. */ #define EXTRACT_MOVW_MOVT_IMM_T(insn1, insn2) \ ((bits ((insn1), 0, 3) << 12) \ | (bits ((insn1), 10, 10) << 11) \ | (bits ((insn2), 12, 14) << 8) \ | bits ((insn2), 0, 7)) /* Extract the immediate from instruction movw/movt of encoding A. INSN is the 32-bit instruction. */ #define EXTRACT_MOVW_MOVT_IMM_A(insn) \ ((bits ((insn), 16, 19) << 12) \ | bits ((insn), 0, 11)) /* Decode immediate value; implements ThumbExpandImmediate pseudo-op. */ static unsigned int thumb_expand_immediate (unsigned int imm) { unsigned int count = imm >> 7; if (count < 8) switch (count / 2) { case 0: return imm & 0xff; case 1: return (imm & 0xff) | ((imm & 0xff) << 16); case 2: return ((imm & 0xff) << 8) | ((imm & 0xff) << 24); case 3: return (imm & 0xff) | ((imm & 0xff) << 8) | ((imm & 0xff) << 16) | ((imm & 0xff) << 24); } return (0x80 | (imm & 0x7f)) << (32 - count); } /* Return 1 if the 16-bit Thumb instruction INSN restores SP in epilogue, 0 otherwise. */ static int thumb_instruction_restores_sp (unsigned short insn) { return (insn == 0x46bd /* mov sp, r7 */ || (insn & 0xff80) == 0xb000 /* add sp, imm */ || (insn & 0xfe00) == 0xbc00); /* pop */ } /* Analyze a Thumb prologue, looking for a recognizable stack frame and frame pointer. Scan until we encounter a store that could clobber the stack frame unexpectedly, or an unknown instruction. Return the last address which is definitely safe to skip for an initial breakpoint. */ static CORE_ADDR thumb_analyze_prologue (struct gdbarch *gdbarch, CORE_ADDR start, CORE_ADDR limit, struct arm_prologue_cache *cache) { arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch); int i; pv_t regs[16]; CORE_ADDR offset; CORE_ADDR unrecognized_pc = 0; for (i = 0; i < 16; i++) regs[i] = pv_register (i, 0); pv_area stack (ARM_SP_REGNUM, gdbarch_addr_bit (gdbarch)); while (start < limit) { unsigned short insn; gdb::optional ra_signed_state; insn = read_code_unsigned_integer (start, 2, byte_order_for_code); if ((insn & 0xfe00) == 0xb400) /* push { rlist } */ { int regno; int mask; if (stack.store_would_trash (regs[ARM_SP_REGNUM])) break; /* Bits 0-7 contain a mask for registers R0-R7. Bit 8 says whether to save LR (R14). */ mask = (insn & 0xff) | ((insn & 0x100) << 6); /* Calculate offsets of saved R0-R7 and LR. */ for (regno = ARM_LR_REGNUM; regno >= 0; regno--) if (mask & (1 << regno)) { regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], -4); stack.store (regs[ARM_SP_REGNUM], 4, regs[regno]); } } else if ((insn & 0xff80) == 0xb080) /* sub sp, #imm */ { offset = (insn & 0x7f) << 2; /* get scaled offset */ regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], -offset); } else if (thumb_instruction_restores_sp (insn)) { /* Don't scan past the epilogue. */ break; } else if ((insn & 0xf800) == 0xa800) /* add Rd, sp, #imm */ regs[bits (insn, 8, 10)] = pv_add_constant (regs[ARM_SP_REGNUM], (insn & 0xff) << 2); else if ((insn & 0xfe00) == 0x1c00 /* add Rd, Rn, #imm */ && pv_is_register (regs[bits (insn, 3, 5)], ARM_SP_REGNUM)) regs[bits (insn, 0, 2)] = pv_add_constant (regs[bits (insn, 3, 5)], bits (insn, 6, 8)); else if ((insn & 0xf800) == 0x3000 /* add Rd, #imm */ && pv_is_register (regs[bits (insn, 8, 10)], ARM_SP_REGNUM)) regs[bits (insn, 8, 10)] = pv_add_constant (regs[bits (insn, 8, 10)], bits (insn, 0, 7)); else if ((insn & 0xfe00) == 0x1800 /* add Rd, Rn, Rm */ && pv_is_register (regs[bits (insn, 6, 8)], ARM_SP_REGNUM) && pv_is_constant (regs[bits (insn, 3, 5)])) regs[bits (insn, 0, 2)] = pv_add (regs[bits (insn, 3, 5)], regs[bits (insn, 6, 8)]); else if ((insn & 0xff00) == 0x4400 /* add Rd, Rm */ && pv_is_constant (regs[bits (insn, 3, 6)])) { int rd = (bit (insn, 7) << 3) + bits (insn, 0, 2); int rm = bits (insn, 3, 6); regs[rd] = pv_add (regs[rd], regs[rm]); } else if ((insn & 0xff00) == 0x4600) /* mov hi, lo or mov lo, hi */ { int dst_reg = (insn & 0x7) + ((insn & 0x80) >> 4); int src_reg = (insn & 0x78) >> 3; regs[dst_reg] = regs[src_reg]; } else if ((insn & 0xf800) == 0x9000) /* str rd, [sp, #off] */ { /* Handle stores to the stack. Normally pushes are used, but with GCC -mtpcs-frame, there may be other stores in the prologue to create the frame. */ int regno = (insn >> 8) & 0x7; pv_t addr; offset = (insn & 0xff) << 2; addr = pv_add_constant (regs[ARM_SP_REGNUM], offset); if (stack.store_would_trash (addr)) break; stack.store (addr, 4, regs[regno]); } else if ((insn & 0xf800) == 0x6000) /* str rd, [rn, #off] */ { int rd = bits (insn, 0, 2); int rn = bits (insn, 3, 5); pv_t addr; offset = bits (insn, 6, 10) << 2; addr = pv_add_constant (regs[rn], offset); if (stack.store_would_trash (addr)) break; stack.store (addr, 4, regs[rd]); } else if (((insn & 0xf800) == 0x7000 /* strb Rd, [Rn, #off] */ || (insn & 0xf800) == 0x8000) /* strh Rd, [Rn, #off] */ && pv_is_register (regs[bits (insn, 3, 5)], ARM_SP_REGNUM)) /* Ignore stores of argument registers to the stack. */ ; else if ((insn & 0xf800) == 0xc800 /* ldmia Rn!, { registers } */ && pv_is_register (regs[bits (insn, 8, 10)], ARM_SP_REGNUM)) /* Ignore block loads from the stack, potentially copying parameters from memory. */ ; else if ((insn & 0xf800) == 0x9800 /* ldr Rd, [Rn, #immed] */ || ((insn & 0xf800) == 0x6800 /* ldr Rd, [sp, #immed] */ && pv_is_register (regs[bits (insn, 3, 5)], ARM_SP_REGNUM))) /* Similarly ignore single loads from the stack. */ ; else if ((insn & 0xffc0) == 0x0000 /* lsls Rd, Rm, #0 */ || (insn & 0xffc0) == 0x1c00) /* add Rd, Rn, #0 */ /* Skip register copies, i.e. saves to another register instead of the stack. */ ; else if ((insn & 0xf800) == 0x2000) /* movs Rd, #imm */ /* Recognize constant loads; even with small stacks these are necessary on Thumb. */ regs[bits (insn, 8, 10)] = pv_constant (bits (insn, 0, 7)); else if ((insn & 0xf800) == 0x4800) /* ldr Rd, [pc, #imm] */ { /* Constant pool loads, for the same reason. */ unsigned int constant; CORE_ADDR loc; loc = start + 4 + bits (insn, 0, 7) * 4; constant = read_memory_unsigned_integer (loc, 4, byte_order); regs[bits (insn, 8, 10)] = pv_constant (constant); } else if (thumb_insn_size (insn) == 4) /* 32-bit Thumb-2 instructions. */ { unsigned short inst2; inst2 = read_code_unsigned_integer (start + 2, 2, byte_order_for_code); uint32_t whole_insn = (insn << 16) | inst2; if ((insn & 0xf800) == 0xf000 && (inst2 & 0xe800) == 0xe800) { /* BL, BLX. Allow some special function calls when skipping the prologue; GCC generates these before storing arguments to the stack. */ CORE_ADDR nextpc; int j1, j2, imm1, imm2; imm1 = sbits (insn, 0, 10); imm2 = bits (inst2, 0, 10); j1 = bit (inst2, 13); j2 = bit (inst2, 11); offset = ((imm1 << 12) + (imm2 << 1)); offset ^= ((!j2) << 22) | ((!j1) << 23); nextpc = start + 4 + offset; /* For BLX make sure to clear the low bits. */ if (bit (inst2, 12) == 0) nextpc = nextpc & 0xfffffffc; if (!skip_prologue_function (gdbarch, nextpc, bit (inst2, 12) != 0)) break; } else if ((insn & 0xffd0) == 0xe900 /* stmdb Rn{!}, { registers } */ && pv_is_register (regs[bits (insn, 0, 3)], ARM_SP_REGNUM)) { pv_t addr = regs[bits (insn, 0, 3)]; int regno; if (stack.store_would_trash (addr)) break; /* Calculate offsets of saved registers. */ for (regno = ARM_LR_REGNUM; regno >= 0; regno--) if (inst2 & (1 << regno)) { addr = pv_add_constant (addr, -4); stack.store (addr, 4, regs[regno]); } if (insn & 0x0020) regs[bits (insn, 0, 3)] = addr; } /* vstmdb Rn{!}, { D-registers } (aka vpush). */ else if ((insn & 0xff20) == 0xed20 && (inst2 & 0x0f00) == 0x0b00 && pv_is_register (regs[bits (insn, 0, 3)], ARM_SP_REGNUM)) { /* Address SP points to. */ pv_t addr = regs[bits (insn, 0, 3)]; /* Number of registers saved. */ unsigned int number = bits (inst2, 0, 7) >> 1; /* First register to save. */ int vd = bits (inst2, 12, 15) | (bits (insn, 6, 6) << 4); if (stack.store_would_trash (addr)) break; /* Calculate offsets of saved registers. */ for (; number > 0; number--) { addr = pv_add_constant (addr, -8); stack.store (addr, 8, pv_register (ARM_D0_REGNUM + vd + number, 0)); } /* Writeback SP to account for the saved registers. */ regs[bits (insn, 0, 3)] = addr; } else if ((insn & 0xff50) == 0xe940 /* strd Rt, Rt2, [Rn, #+/-imm]{!} */ && pv_is_register (regs[bits (insn, 0, 3)], ARM_SP_REGNUM)) { int regno1 = bits (inst2, 12, 15); int regno2 = bits (inst2, 8, 11); pv_t addr = regs[bits (insn, 0, 3)]; offset = inst2 & 0xff; if (insn & 0x0080) addr = pv_add_constant (addr, offset); else addr = pv_add_constant (addr, -offset); if (stack.store_would_trash (addr)) break; stack.store (addr, 4, regs[regno1]); stack.store (pv_add_constant (addr, 4), 4, regs[regno2]); if (insn & 0x0020) regs[bits (insn, 0, 3)] = addr; } else if ((insn & 0xfff0) == 0xf8c0 /* str Rt,[Rn,+/-#imm]{!} */ && (inst2 & 0x0c00) == 0x0c00 && pv_is_register (regs[bits (insn, 0, 3)], ARM_SP_REGNUM)) { int regno = bits (inst2, 12, 15); pv_t addr = regs[bits (insn, 0, 3)]; offset = inst2 & 0xff; if (inst2 & 0x0200) addr = pv_add_constant (addr, offset); else addr = pv_add_constant (addr, -offset); if (stack.store_would_trash (addr)) break; stack.store (addr, 4, regs[regno]); if (inst2 & 0x0100) regs[bits (insn, 0, 3)] = addr; } else if ((insn & 0xfff0) == 0xf8c0 /* str.w Rt,[Rn,#imm] */ && pv_is_register (regs[bits (insn, 0, 3)], ARM_SP_REGNUM)) { int regno = bits (inst2, 12, 15); pv_t addr; offset = inst2 & 0xfff; addr = pv_add_constant (regs[bits (insn, 0, 3)], offset); if (stack.store_would_trash (addr)) break; stack.store (addr, 4, regs[regno]); } else if ((insn & 0xffd0) == 0xf880 /* str{bh}.w Rt,[Rn,#imm] */ && pv_is_register (regs[bits (insn, 0, 3)], ARM_SP_REGNUM)) /* Ignore stores of argument registers to the stack. */ ; else if ((insn & 0xffd0) == 0xf800 /* str{bh} Rt,[Rn,#+/-imm] */ && (inst2 & 0x0d00) == 0x0c00 && pv_is_register (regs[bits (insn, 0, 3)], ARM_SP_REGNUM)) /* Ignore stores of argument registers to the stack. */ ; else if ((insn & 0xffd0) == 0xe890 /* ldmia Rn[!], { registers } */ && (inst2 & 0x8000) == 0x0000 && pv_is_register (regs[bits (insn, 0, 3)], ARM_SP_REGNUM)) /* Ignore block loads from the stack, potentially copying parameters from memory. */ ; else if ((insn & 0xff70) == 0xe950 /* ldrd Rt, Rt2, [Rn, #+/-imm] */ && pv_is_register (regs[bits (insn, 0, 3)], ARM_SP_REGNUM)) /* Similarly ignore dual loads from the stack. */ ; else if ((insn & 0xfff0) == 0xf850 /* ldr Rt,[Rn,#+/-imm] */ && (inst2 & 0x0d00) == 0x0c00 && pv_is_register (regs[bits (insn, 0, 3)], ARM_SP_REGNUM)) /* Similarly ignore single loads from the stack. */ ; else if ((insn & 0xfff0) == 0xf8d0 /* ldr.w Rt,[Rn,#imm] */ && pv_is_register (regs[bits (insn, 0, 3)], ARM_SP_REGNUM)) /* Similarly ignore single loads from the stack. */ ; else if ((insn & 0xfbf0) == 0xf100 /* add.w Rd, Rn, #imm */ && (inst2 & 0x8000) == 0x0000) { unsigned int imm = ((bits (insn, 10, 10) << 11) | (bits (inst2, 12, 14) << 8) | bits (inst2, 0, 7)); regs[bits (inst2, 8, 11)] = pv_add_constant (regs[bits (insn, 0, 3)], thumb_expand_immediate (imm)); } else if ((insn & 0xfbf0) == 0xf200 /* addw Rd, Rn, #imm */ && (inst2 & 0x8000) == 0x0000) { unsigned int imm = ((bits (insn, 10, 10) << 11) | (bits (inst2, 12, 14) << 8) | bits (inst2, 0, 7)); regs[bits (inst2, 8, 11)] = pv_add_constant (regs[bits (insn, 0, 3)], imm); } else if ((insn & 0xfbf0) == 0xf1a0 /* sub.w Rd, Rn, #imm */ && (inst2 & 0x8000) == 0x0000) { unsigned int imm = ((bits (insn, 10, 10) << 11) | (bits (inst2, 12, 14) << 8) | bits (inst2, 0, 7)); regs[bits (inst2, 8, 11)] = pv_add_constant (regs[bits (insn, 0, 3)], - (CORE_ADDR) thumb_expand_immediate (imm)); } else if ((insn & 0xfbf0) == 0xf2a0 /* subw Rd, Rn, #imm */ && (inst2 & 0x8000) == 0x0000) { unsigned int imm = ((bits (insn, 10, 10) << 11) | (bits (inst2, 12, 14) << 8) | bits (inst2, 0, 7)); regs[bits (inst2, 8, 11)] = pv_add_constant (regs[bits (insn, 0, 3)], - (CORE_ADDR) imm); } else if ((insn & 0xfbff) == 0xf04f) /* mov.w Rd, #const */ { unsigned int imm = ((bits (insn, 10, 10) << 11) | (bits (inst2, 12, 14) << 8) | bits (inst2, 0, 7)); regs[bits (inst2, 8, 11)] = pv_constant (thumb_expand_immediate (imm)); } else if ((insn & 0xfbf0) == 0xf240) /* movw Rd, #const */ { unsigned int imm = EXTRACT_MOVW_MOVT_IMM_T (insn, inst2); regs[bits (inst2, 8, 11)] = pv_constant (imm); } else if (insn == 0xea5f /* mov.w Rd,Rm */ && (inst2 & 0xf0f0) == 0) { int dst_reg = (inst2 & 0x0f00) >> 8; int src_reg = inst2 & 0xf; regs[dst_reg] = regs[src_reg]; } else if ((insn & 0xff7f) == 0xf85f) /* ldr.w Rt, */ { /* Constant pool loads. */ unsigned int constant; CORE_ADDR loc; offset = bits (inst2, 0, 11); if (insn & 0x0080) loc = start + 4 + offset; else loc = start + 4 - offset; constant = read_memory_unsigned_integer (loc, 4, byte_order); regs[bits (inst2, 12, 15)] = pv_constant (constant); } else if ((insn & 0xff7f) == 0xe95f) /* ldrd Rt,Rt2, */ { /* Constant pool loads. */ unsigned int constant; CORE_ADDR loc; offset = bits (inst2, 0, 7) << 2; if (insn & 0x0080) loc = start + 4 + offset; else loc = start + 4 - offset; constant = read_memory_unsigned_integer (loc, 4, byte_order); regs[bits (inst2, 12, 15)] = pv_constant (constant); constant = read_memory_unsigned_integer (loc + 4, 4, byte_order); regs[bits (inst2, 8, 11)] = pv_constant (constant); } /* Start of ARMv8.1-m PACBTI extension instructions. */ else if (IS_PAC (whole_insn)) { /* LR and SP are input registers. PAC is in R12. LR is signed from this point onwards. NOP space. */ ra_signed_state = true; } else if (IS_PACBTI (whole_insn)) { /* LR and SP are input registers. PAC is in R12 and PC is a valid BTI landing pad. LR is signed from this point onwards. NOP space. */ ra_signed_state = true; } else if (IS_BTI (whole_insn)) { /* Valid BTI landing pad. NOP space. */ } else if (IS_PACG (whole_insn)) { /* Sign Rn using Rm and store the PAC in Rd. Rd is signed from this point onwards. */ ra_signed_state = true; } else if (IS_AUT (whole_insn) || IS_AUTG (whole_insn)) { /* These instructions appear close to the epilogue, when signed pointers are getting authenticated. */ ra_signed_state = false; } /* End of ARMv8.1-m PACBTI extension instructions */ else if (thumb2_instruction_changes_pc (insn, inst2)) { /* Don't scan past anything that might change control flow. */ break; } else { /* The optimizer might shove anything into the prologue, so we just skip what we don't recognize. */ unrecognized_pc = start; } /* Make sure we are dealing with a target that supports ARMv8.1-m PACBTI. */ if (cache != nullptr && tdep->have_pacbti && ra_signed_state.has_value ()) { arm_debug_printf ("Found pacbti instruction at %s", paddress (gdbarch, start)); arm_debug_printf ("RA is %s", *ra_signed_state? "signed" : "not signed"); cache->ra_signed_state = ra_signed_state; } start += 2; } else if (thumb_instruction_changes_pc (insn)) { /* Don't scan past anything that might change control flow. */ break; } else { /* The optimizer might shove anything into the prologue, so we just skip what we don't recognize. */ unrecognized_pc = start; } start += 2; } arm_debug_printf ("Prologue scan stopped at %s", paddress (gdbarch, start)); if (unrecognized_pc == 0) unrecognized_pc = start; if (cache == NULL) return unrecognized_pc; if (pv_is_register (regs[ARM_FP_REGNUM], ARM_SP_REGNUM)) { /* Frame pointer is fp. Frame size is constant. */ cache->framereg = ARM_FP_REGNUM; cache->framesize = -regs[ARM_FP_REGNUM].k; } else if (pv_is_register (regs[THUMB_FP_REGNUM], ARM_SP_REGNUM)) { /* Frame pointer is r7. Frame size is constant. */ cache->framereg = THUMB_FP_REGNUM; cache->framesize = -regs[THUMB_FP_REGNUM].k; } else { /* Try the stack pointer... this is a bit desperate. */ cache->framereg = ARM_SP_REGNUM; cache->framesize = -regs[ARM_SP_REGNUM].k; } for (i = 0; i < gdbarch_num_regs (gdbarch); i++) if (stack.find_reg (gdbarch, i, &offset)) { cache->saved_regs[i].set_addr (offset); if (i == ARM_SP_REGNUM) arm_cache_set_active_sp_value(cache, tdep, offset); } return unrecognized_pc; } /* Try to analyze the instructions starting from PC, which load symbol __stack_chk_guard. Return the address of instruction after loading this symbol, set the dest register number to *BASEREG, and set the size of instructions for loading symbol in OFFSET. Return 0 if instructions are not recognized. */ static CORE_ADDR arm_analyze_load_stack_chk_guard(CORE_ADDR pc, struct gdbarch *gdbarch, unsigned int *destreg, int *offset) { enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch); int is_thumb = arm_pc_is_thumb (gdbarch, pc); unsigned int low, high, address; address = 0; if (is_thumb) { unsigned short insn1 = read_code_unsigned_integer (pc, 2, byte_order_for_code); if ((insn1 & 0xf800) == 0x4800) /* ldr Rd, #immed */ { *destreg = bits (insn1, 8, 10); *offset = 2; address = (pc & 0xfffffffc) + 4 + (bits (insn1, 0, 7) << 2); address = read_memory_unsigned_integer (address, 4, byte_order_for_code); } else if ((insn1 & 0xfbf0) == 0xf240) /* movw Rd, #const */ { unsigned short insn2 = read_code_unsigned_integer (pc + 2, 2, byte_order_for_code); low = EXTRACT_MOVW_MOVT_IMM_T (insn1, insn2); insn1 = read_code_unsigned_integer (pc + 4, 2, byte_order_for_code); insn2 = read_code_unsigned_integer (pc + 6, 2, byte_order_for_code); /* movt Rd, #const */ if ((insn1 & 0xfbc0) == 0xf2c0) { high = EXTRACT_MOVW_MOVT_IMM_T (insn1, insn2); *destreg = bits (insn2, 8, 11); *offset = 8; address = (high << 16 | low); } } } else { unsigned int insn = read_code_unsigned_integer (pc, 4, byte_order_for_code); if ((insn & 0x0e5f0000) == 0x041f0000) /* ldr Rd, [PC, #immed] */ { address = bits (insn, 0, 11) + pc + 8; address = read_memory_unsigned_integer (address, 4, byte_order_for_code); *destreg = bits (insn, 12, 15); *offset = 4; } else if ((insn & 0x0ff00000) == 0x03000000) /* movw Rd, #const */ { low = EXTRACT_MOVW_MOVT_IMM_A (insn); insn = read_code_unsigned_integer (pc + 4, 4, byte_order_for_code); if ((insn & 0x0ff00000) == 0x03400000) /* movt Rd, #const */ { high = EXTRACT_MOVW_MOVT_IMM_A (insn); *destreg = bits (insn, 12, 15); *offset = 8; address = (high << 16 | low); } } } return address; } /* Try to skip a sequence of instructions used for stack protector. If PC points to the first instruction of this sequence, return the address of first instruction after this sequence, otherwise, return original PC. On arm, this sequence of instructions is composed of mainly three steps, Step 1: load symbol __stack_chk_guard, Step 2: load from address of __stack_chk_guard, Step 3: store it to somewhere else. Usually, instructions on step 2 and step 3 are the same on various ARM architectures. On step 2, it is one instruction 'ldr Rx, [Rn, #0]', and on step 3, it is also one instruction 'str Rx, [r7, #immd]'. However, instructions in step 1 vary from different ARM architectures. On ARMv7, they are, movw Rn, #:lower16:__stack_chk_guard movt Rn, #:upper16:__stack_chk_guard On ARMv5t, it is, ldr Rn, .Label .... .Lable: .word __stack_chk_guard Since ldr/str is a very popular instruction, we can't use them as 'fingerprint' or 'signature' of stack protector sequence. Here we choose sequence {movw/movt, ldr}/ldr/str plus symbol __stack_chk_guard, if not stripped, as the 'fingerprint' of a stack protector cdoe sequence. */ static CORE_ADDR arm_skip_stack_protector(CORE_ADDR pc, struct gdbarch *gdbarch) { enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch); unsigned int basereg; struct bound_minimal_symbol stack_chk_guard; int offset; int is_thumb = arm_pc_is_thumb (gdbarch, pc); CORE_ADDR addr; /* Try to parse the instructions in Step 1. */ addr = arm_analyze_load_stack_chk_guard (pc, gdbarch, &basereg, &offset); if (!addr) return pc; stack_chk_guard = lookup_minimal_symbol_by_pc (addr); /* ADDR must correspond to a symbol whose name is __stack_chk_guard. Otherwise, this sequence cannot be for stack protector. */ if (stack_chk_guard.minsym == NULL || !startswith (stack_chk_guard.minsym->linkage_name (), "__stack_chk_guard")) return pc; if (is_thumb) { unsigned int destreg; unsigned short insn = read_code_unsigned_integer (pc + offset, 2, byte_order_for_code); /* Step 2: ldr Rd, [Rn, #immed], encoding T1. */ if ((insn & 0xf800) != 0x6800) return pc; if (bits (insn, 3, 5) != basereg) return pc; destreg = bits (insn, 0, 2); insn = read_code_unsigned_integer (pc + offset + 2, 2, byte_order_for_code); /* Step 3: str Rd, [Rn, #immed], encoding T1. */ if ((insn & 0xf800) != 0x6000) return pc; if (destreg != bits (insn, 0, 2)) return pc; } else { unsigned int destreg; unsigned int insn = read_code_unsigned_integer (pc + offset, 4, byte_order_for_code); /* Step 2: ldr Rd, [Rn, #immed], encoding A1. */ if ((insn & 0x0e500000) != 0x04100000) return pc; if (bits (insn, 16, 19) != basereg) return pc; destreg = bits (insn, 12, 15); /* Step 3: str Rd, [Rn, #immed], encoding A1. */ insn = read_code_unsigned_integer (pc + offset + 4, 4, byte_order_for_code); if ((insn & 0x0e500000) != 0x04000000) return pc; if (bits (insn, 12, 15) != destreg) return pc; } /* The size of total two instructions ldr/str is 4 on Thumb-2, while 8 on arm. */ if (is_thumb) return pc + offset + 4; else return pc + offset + 8; } /* Advance the PC across any function entry prologue instructions to reach some "real" code. The APCS (ARM Procedure Call Standard) defines the following prologue: mov ip, sp [stmfd sp!, {a1,a2,a3,a4}] stmfd sp!, {...,fp,ip,lr,pc} [stfe f7, [sp, #-12]!] [stfe f6, [sp, #-12]!] [stfe f5, [sp, #-12]!] [stfe f4, [sp, #-12]!] sub fp, ip, #nn @@ nn == 20 or 4 depending on second insn. */ static CORE_ADDR arm_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc) { CORE_ADDR func_addr, limit_pc; /* See if we can determine the end of the prologue via the symbol table. If so, then return either PC, or the PC after the prologue, whichever is greater. */ if (find_pc_partial_function (pc, NULL, &func_addr, NULL)) { CORE_ADDR post_prologue_pc = skip_prologue_using_sal (gdbarch, func_addr); struct compunit_symtab *cust = find_pc_compunit_symtab (func_addr); if (post_prologue_pc) post_prologue_pc = arm_skip_stack_protector (post_prologue_pc, gdbarch); /* GCC always emits a line note before the prologue and another one after, even if the two are at the same address or on the same line. Take advantage of this so that we do not need to know every instruction that might appear in the prologue. We will have producer information for most binaries; if it is missing (e.g. for -gstabs), assuming the GNU tools. */ if (post_prologue_pc && (cust == NULL || cust->producer () == NULL || startswith (cust->producer (), "GNU ") || producer_is_llvm (cust->producer ()))) return post_prologue_pc; if (post_prologue_pc != 0) { CORE_ADDR analyzed_limit; /* For non-GCC compilers, make sure the entire line is an acceptable prologue; GDB will round this function's return value up to the end of the following line so we can not skip just part of a line (and we do not want to). RealView does not treat the prologue specially, but does associate prologue code with the opening brace; so this lets us skip the first line if we think it is the opening brace. */ if (arm_pc_is_thumb (gdbarch, func_addr)) analyzed_limit = thumb_analyze_prologue (gdbarch, func_addr, post_prologue_pc, NULL); else analyzed_limit = arm_analyze_prologue (gdbarch, func_addr, post_prologue_pc, NULL, target_arm_instruction_reader ()); if (analyzed_limit != post_prologue_pc) return func_addr; return post_prologue_pc; } } /* Can't determine prologue from the symbol table, need to examine instructions. */ /* Find an upper limit on the function prologue using the debug information. If the debug information could not be used to provide that bound, then use an arbitrary large number as the upper bound. */ /* Like arm_scan_prologue, stop no later than pc + 64. */ limit_pc = skip_prologue_using_sal (gdbarch, pc); if (limit_pc == 0) limit_pc = pc + 64; /* Magic. */ /* Check if this is Thumb code. */ if (arm_pc_is_thumb (gdbarch, pc)) return thumb_analyze_prologue (gdbarch, pc, limit_pc, NULL); else return arm_analyze_prologue (gdbarch, pc, limit_pc, NULL, target_arm_instruction_reader ()); } /* Function: thumb_scan_prologue (helper function for arm_scan_prologue) This function decodes a Thumb function prologue to determine: 1) the size of the stack frame 2) which registers are saved on it 3) the offsets of saved regs 4) the offset from the stack pointer to the frame pointer A typical Thumb function prologue would create this stack frame (offsets relative to FP) old SP -> 24 stack parameters 20 LR 16 R7 R7 -> 0 local variables (16 bytes) SP -> -12 additional stack space (12 bytes) The frame size would thus be 36 bytes, and the frame offset would be 12 bytes. The frame register is R7. The comments for thumb_skip_prolog() describe the algorithm we use to detect the end of the prolog. */ static void thumb_scan_prologue (struct gdbarch *gdbarch, CORE_ADDR prev_pc, CORE_ADDR block_addr, struct arm_prologue_cache *cache) { CORE_ADDR prologue_start; CORE_ADDR prologue_end; if (find_pc_partial_function (block_addr, NULL, &prologue_start, &prologue_end)) { /* See comment in arm_scan_prologue for an explanation of this heuristics. */ if (prologue_end > prologue_start + 64) { prologue_end = prologue_start + 64; } } else /* We're in the boondocks: we have no idea where the start of the function is. */ return; prologue_end = std::min (prologue_end, prev_pc); thumb_analyze_prologue (gdbarch, prologue_start, prologue_end, cache); } /* Return 1 if the ARM instruction INSN restores SP in epilogue, 0 otherwise. */ static int arm_instruction_restores_sp (unsigned int insn) { if (bits (insn, 28, 31) != INST_NV) { if ((insn & 0x0df0f000) == 0x0080d000 /* ADD SP (register or immediate). */ || (insn & 0x0df0f000) == 0x0040d000 /* SUB SP (register or immediate). */ || (insn & 0x0ffffff0) == 0x01a0d000 /* MOV SP. */ || (insn & 0x0fff0000) == 0x08bd0000 /* POP (LDMIA). */ || (insn & 0x0fff0000) == 0x049d0000) /* POP of a single register. */ return 1; } return 0; } /* Implement immediate value decoding, as described in section A5.2.4 (Modified immediate constants in ARM instructions) of the ARM Architecture Reference Manual (ARMv7-A and ARMv7-R edition). */ static uint32_t arm_expand_immediate (uint32_t imm) { /* Immediate values are 12 bits long. */ gdb_assert ((imm & 0xfffff000) == 0); uint32_t unrotated_value = imm & 0xff; uint32_t rotate_amount = (imm & 0xf00) >> 7; if (rotate_amount == 0) return unrotated_value; return ((unrotated_value >> rotate_amount) | (unrotated_value << (32 - rotate_amount))); } /* Analyze an ARM mode prologue starting at PROLOGUE_START and continuing no further than PROLOGUE_END. If CACHE is non-NULL, fill it in. Return the first address not recognized as a prologue instruction. We recognize all the instructions typically found in ARM prologues, plus harmless instructions which can be skipped (either for analysis purposes, or a more restrictive set that can be skipped when finding the end of the prologue). */ static CORE_ADDR arm_analyze_prologue (struct gdbarch *gdbarch, CORE_ADDR prologue_start, CORE_ADDR prologue_end, struct arm_prologue_cache *cache, const arm_instruction_reader &insn_reader) { enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch); int regno; CORE_ADDR offset, current_pc; pv_t regs[ARM_FPS_REGNUM]; CORE_ADDR unrecognized_pc = 0; arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); /* Search the prologue looking for instructions that set up the frame pointer, adjust the stack pointer, and save registers. Be careful, however, and if it doesn't look like a prologue, don't try to scan it. If, for instance, a frameless function begins with stmfd sp!, then we will tell ourselves there is a frame, which will confuse stack traceback, as well as "finish" and other operations that rely on a knowledge of the stack traceback. */ for (regno = 0; regno < ARM_FPS_REGNUM; regno++) regs[regno] = pv_register (regno, 0); pv_area stack (ARM_SP_REGNUM, gdbarch_addr_bit (gdbarch)); for (current_pc = prologue_start; current_pc < prologue_end; current_pc += 4) { uint32_t insn = insn_reader.read (current_pc, byte_order_for_code); if (insn == 0xe1a0c00d) /* mov ip, sp */ { regs[ARM_IP_REGNUM] = regs[ARM_SP_REGNUM]; continue; } else if ((insn & 0xfff00000) == 0xe2800000 /* add Rd, Rn, #n */ && pv_is_register (regs[bits (insn, 16, 19)], ARM_SP_REGNUM)) { uint32_t imm = arm_expand_immediate (insn & 0xfff); int rd = bits (insn, 12, 15); regs[rd] = pv_add_constant (regs[bits (insn, 16, 19)], imm); continue; } else if ((insn & 0xfff00000) == 0xe2400000 /* sub Rd, Rn, #n */ && pv_is_register (regs[bits (insn, 16, 19)], ARM_SP_REGNUM)) { uint32_t imm = arm_expand_immediate (insn & 0xfff); int rd = bits (insn, 12, 15); regs[rd] = pv_add_constant (regs[bits (insn, 16, 19)], -imm); continue; } else if ((insn & 0xffff0fff) == 0xe52d0004) /* str Rd, [sp, #-4]! */ { if (stack.store_would_trash (regs[ARM_SP_REGNUM])) break; regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], -4); stack.store (regs[ARM_SP_REGNUM], 4, regs[bits (insn, 12, 15)]); continue; } else if ((insn & 0xffff0000) == 0xe92d0000) /* stmfd sp!, {..., fp, ip, lr, pc} or stmfd sp!, {a1, a2, a3, a4} */ { int mask = insn & 0xffff; if (stack.store_would_trash (regs[ARM_SP_REGNUM])) break; /* Calculate offsets of saved registers. */ for (regno = ARM_PC_REGNUM; regno >= 0; regno--) if (mask & (1 << regno)) { regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], -4); stack.store (regs[ARM_SP_REGNUM], 4, regs[regno]); } } else if ((insn & 0xffff0000) == 0xe54b0000 /* strb rx,[r11,#-n] */ || (insn & 0xffff00f0) == 0xe14b00b0 /* strh rx,[r11,#-n] */ || (insn & 0xffffc000) == 0xe50b0000) /* str rx,[r11,#-n] */ { /* No need to add this to saved_regs -- it's just an arg reg. */ continue; } else if ((insn & 0xffff0000) == 0xe5cd0000 /* strb rx,[sp,#n] */ || (insn & 0xffff00f0) == 0xe1cd00b0 /* strh rx,[sp,#n] */ || (insn & 0xffffc000) == 0xe58d0000) /* str rx,[sp,#n] */ { /* No need to add this to saved_regs -- it's just an arg reg. */ continue; } else if ((insn & 0xfff00000) == 0xe8800000 /* stm Rn, { registers } */ && pv_is_register (regs[bits (insn, 16, 19)], ARM_SP_REGNUM)) { /* No need to add this to saved_regs -- it's just arg regs. */ continue; } else if ((insn & 0xfffff000) == 0xe24cb000) /* sub fp, ip #n */ { uint32_t imm = arm_expand_immediate (insn & 0xfff); regs[ARM_FP_REGNUM] = pv_add_constant (regs[ARM_IP_REGNUM], -imm); } else if ((insn & 0xfffff000) == 0xe24dd000) /* sub sp, sp #n */ { uint32_t imm = arm_expand_immediate(insn & 0xfff); regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], -imm); } else if ((insn & 0xffff7fff) == 0xed6d0103 /* stfe f?, [sp, -#c]! */ && tdep->have_fpa_registers) { if (stack.store_would_trash (regs[ARM_SP_REGNUM])) break; regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], -12); regno = ARM_F0_REGNUM + ((insn >> 12) & 0x07); stack.store (regs[ARM_SP_REGNUM], 12, regs[regno]); } else if ((insn & 0xffbf0fff) == 0xec2d0200 /* sfmfd f0, 4, [sp!] */ && tdep->have_fpa_registers) { int n_saved_fp_regs; unsigned int fp_start_reg, fp_bound_reg; if (stack.store_would_trash (regs[ARM_SP_REGNUM])) break; if ((insn & 0x800) == 0x800) /* N0 is set */ { if ((insn & 0x40000) == 0x40000) /* N1 is set */ n_saved_fp_regs = 3; else n_saved_fp_regs = 1; } else { if ((insn & 0x40000) == 0x40000) /* N1 is set */ n_saved_fp_regs = 2; else n_saved_fp_regs = 4; } fp_start_reg = ARM_F0_REGNUM + ((insn >> 12) & 0x7); fp_bound_reg = fp_start_reg + n_saved_fp_regs; for (; fp_start_reg < fp_bound_reg; fp_start_reg++) { regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], -12); stack.store (regs[ARM_SP_REGNUM], 12, regs[fp_start_reg++]); } } else if ((insn & 0xff000000) == 0xeb000000 && cache == NULL) /* bl */ { /* Allow some special function calls when skipping the prologue; GCC generates these before storing arguments to the stack. */ CORE_ADDR dest = BranchDest (current_pc, insn); if (skip_prologue_function (gdbarch, dest, 0)) continue; else break; } else if ((insn & 0xf0000000) != 0xe0000000) break; /* Condition not true, exit early. */ else if (arm_instruction_changes_pc (insn)) /* Don't scan past anything that might change control flow. */ break; else if (arm_instruction_restores_sp (insn)) { /* Don't scan past the epilogue. */ break; } else if ((insn & 0xfe500000) == 0xe8100000 /* ldm */ && pv_is_register (regs[bits (insn, 16, 19)], ARM_SP_REGNUM)) /* Ignore block loads from the stack, potentially copying parameters from memory. */ continue; else if ((insn & 0xfc500000) == 0xe4100000 && pv_is_register (regs[bits (insn, 16, 19)], ARM_SP_REGNUM)) /* Similarly ignore single loads from the stack. */ continue; else if ((insn & 0xffff0ff0) == 0xe1a00000) /* MOV Rd, Rm. Skip register copies, i.e. saves to another register instead of the stack. */ continue; else { /* The optimizer might shove anything into the prologue, if we build up cache (cache != NULL) from scanning prologue, we just skip what we don't recognize and scan further to make cache as complete as possible. However, if we skip prologue, we'll stop immediately on unrecognized instruction. */ unrecognized_pc = current_pc; if (cache != NULL) continue; else break; } } if (unrecognized_pc == 0) unrecognized_pc = current_pc; if (cache) { int framereg, framesize; /* The frame size is just the distance from the frame register to the original stack pointer. */ if (pv_is_register (regs[ARM_FP_REGNUM], ARM_SP_REGNUM)) { /* Frame pointer is fp. */ framereg = ARM_FP_REGNUM; framesize = -regs[ARM_FP_REGNUM].k; } else { /* Try the stack pointer... this is a bit desperate. */ framereg = ARM_SP_REGNUM; framesize = -regs[ARM_SP_REGNUM].k; } cache->framereg = framereg; cache->framesize = framesize; for (regno = 0; regno < ARM_FPS_REGNUM; regno++) if (stack.find_reg (gdbarch, regno, &offset)) { cache->saved_regs[regno].set_addr (offset); if (regno == ARM_SP_REGNUM) arm_cache_set_active_sp_value(cache, tdep, offset); } } arm_debug_printf ("Prologue scan stopped at %s", paddress (gdbarch, unrecognized_pc)); return unrecognized_pc; } static void arm_scan_prologue (frame_info_ptr this_frame, struct arm_prologue_cache *cache) { struct gdbarch *gdbarch = get_frame_arch (this_frame); enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); CORE_ADDR prologue_start, prologue_end; CORE_ADDR prev_pc = get_frame_pc (this_frame); CORE_ADDR block_addr = get_frame_address_in_block (this_frame); arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); /* Assume there is no frame until proven otherwise. */ cache->framereg = ARM_SP_REGNUM; cache->framesize = 0; /* Check for Thumb prologue. */ if (arm_frame_is_thumb (this_frame)) { thumb_scan_prologue (gdbarch, prev_pc, block_addr, cache); return; } /* Find the function prologue. If we can't find the function in the symbol table, peek in the stack frame to find the PC. */ if (find_pc_partial_function (block_addr, NULL, &prologue_start, &prologue_end)) { /* One way to find the end of the prologue (which works well for unoptimized code) is to do the following: struct symtab_and_line sal = find_pc_line (prologue_start, 0); if (sal.line == 0) prologue_end = prev_pc; else if (sal.end < prologue_end) prologue_end = sal.end; This mechanism is very accurate so long as the optimizer doesn't move any instructions from the function body into the prologue. If this happens, sal.end will be the last instruction in the first hunk of prologue code just before the first instruction that the scheduler has moved from the body to the prologue. In order to make sure that we scan all of the prologue instructions, we use a slightly less accurate mechanism which may scan more than necessary. To help compensate for this lack of accuracy, the prologue scanning loop below contains several clauses which'll cause the loop to terminate early if an implausible prologue instruction is encountered. The expression prologue_start + 64 is a suitable endpoint since it accounts for the largest possible prologue plus up to five instructions inserted by the scheduler. */ if (prologue_end > prologue_start + 64) { prologue_end = prologue_start + 64; /* See above. */ } } else { /* We have no symbol information. Our only option is to assume this function has a standard stack frame and the normal frame register. Then, we can find the value of our frame pointer on entrance to the callee (or at the present moment if this is the innermost frame). The value stored there should be the address of the stmfd + 8. */ CORE_ADDR frame_loc; ULONGEST return_value; /* AAPCS does not use a frame register, so we can abort here. */ if (tdep->arm_abi == ARM_ABI_AAPCS) return; frame_loc = get_frame_register_unsigned (this_frame, ARM_FP_REGNUM); if (!safe_read_memory_unsigned_integer (frame_loc, 4, byte_order, &return_value)) return; else { prologue_start = gdbarch_addr_bits_remove (gdbarch, return_value) - 8; prologue_end = prologue_start + 64; /* See above. */ } } if (prev_pc < prologue_end) prologue_end = prev_pc; arm_analyze_prologue (gdbarch, prologue_start, prologue_end, cache, target_arm_instruction_reader ()); } static struct arm_prologue_cache * arm_make_prologue_cache (frame_info_ptr this_frame) { int reg; struct arm_prologue_cache *cache; CORE_ADDR unwound_fp, prev_sp; cache = FRAME_OBSTACK_ZALLOC (struct arm_prologue_cache); arm_cache_init (cache, this_frame); arm_scan_prologue (this_frame, cache); unwound_fp = get_frame_register_unsigned (this_frame, cache->framereg); if (unwound_fp == 0) return cache; arm_gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (this_frame)); prev_sp = unwound_fp + cache->framesize; arm_cache_set_active_sp_value (cache, tdep, prev_sp); /* Calculate actual addresses of saved registers using offsets determined by arm_scan_prologue. */ for (reg = 0; reg < gdbarch_num_regs (get_frame_arch (this_frame)); reg++) if (cache->saved_regs[reg].is_addr ()) cache->saved_regs[reg].set_addr (cache->saved_regs[reg].addr () + prev_sp); return cache; } /* Implementation of the stop_reason hook for arm_prologue frames. */ static enum unwind_stop_reason arm_prologue_unwind_stop_reason (frame_info_ptr this_frame, void **this_cache) { struct arm_prologue_cache *cache; CORE_ADDR pc; if (*this_cache == NULL) *this_cache = arm_make_prologue_cache (this_frame); cache = (struct arm_prologue_cache *) *this_cache; /* This is meant to halt the backtrace at "_start". */ pc = get_frame_pc (this_frame); gdbarch *arch = get_frame_arch (this_frame); arm_gdbarch_tdep *tdep = gdbarch_tdep (arch); if (pc <= tdep->lowest_pc) return UNWIND_OUTERMOST; /* If we've hit a wall, stop. */ if (arm_cache_get_prev_sp_value (cache, tdep) == 0) return UNWIND_OUTERMOST; return UNWIND_NO_REASON; } /* Our frame ID for a normal frame is the current function's starting PC and the caller's SP when we were called. */ static void arm_prologue_this_id (frame_info_ptr this_frame, void **this_cache, struct frame_id *this_id) { struct arm_prologue_cache *cache; struct frame_id id; CORE_ADDR pc, func; if (*this_cache == NULL) *this_cache = arm_make_prologue_cache (this_frame); cache = (struct arm_prologue_cache *) *this_cache; arm_gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (this_frame)); /* Use function start address as part of the frame ID. If we cannot identify the start address (due to missing symbol information), fall back to just using the current PC. */ pc = get_frame_pc (this_frame); func = get_frame_func (this_frame); if (!func) func = pc; id = frame_id_build (arm_cache_get_prev_sp_value (cache, tdep), func); *this_id = id; } static struct value * arm_prologue_prev_register (frame_info_ptr this_frame, void **this_cache, int prev_regnum) { struct gdbarch *gdbarch = get_frame_arch (this_frame); struct arm_prologue_cache *cache; CORE_ADDR sp_value; if (*this_cache == NULL) *this_cache = arm_make_prologue_cache (this_frame); cache = (struct arm_prologue_cache *) *this_cache; arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); /* If this frame has signed the return address, mark it as so. */ if (tdep->have_pacbti && cache->ra_signed_state.has_value () && *cache->ra_signed_state) set_frame_previous_pc_masked (this_frame); /* If we are asked to unwind the PC, then we need to return the LR instead. The prologue may save PC, but it will point into this frame's prologue, not the next frame's resume location. Also strip the saved T bit. A valid LR may have the low bit set, but a valid PC never does. */ if (prev_regnum == ARM_PC_REGNUM) { CORE_ADDR lr; lr = frame_unwind_register_unsigned (this_frame, ARM_LR_REGNUM); return frame_unwind_got_constant (this_frame, prev_regnum, arm_addr_bits_remove (gdbarch, lr)); } /* SP is generally not saved to the stack, but this frame is identified by the next frame's stack pointer at the time of the call. The value was already reconstructed into PREV_SP. */ if (prev_regnum == ARM_SP_REGNUM) return frame_unwind_got_constant (this_frame, prev_regnum, arm_cache_get_prev_sp_value (cache, tdep)); /* The value might be one of the alternative SP, if so, use the value already constructed. */ if (arm_is_alternative_sp_register (tdep, prev_regnum)) { sp_value = arm_cache_get_sp_register (cache, tdep, prev_regnum); return frame_unwind_got_constant (this_frame, prev_regnum, sp_value); } /* The CPSR may have been changed by the call instruction and by the called function. The only bit we can reconstruct is the T bit, by checking the low bit of LR as of the call. This is a reliable indicator of Thumb-ness except for some ARM v4T pre-interworking Thumb code, which could get away with a clear low bit as long as the called function did not use bx. Guess that all other bits are unchanged; the condition flags are presumably lost, but the processor status is likely valid. */ if (prev_regnum == ARM_PS_REGNUM) { ULONGEST cpsr = get_frame_register_unsigned (this_frame, prev_regnum); CORE_ADDR lr = frame_unwind_register_unsigned (this_frame, ARM_LR_REGNUM); cpsr = reconstruct_t_bit (gdbarch, lr, cpsr); return frame_unwind_got_constant (this_frame, prev_regnum, cpsr); } return trad_frame_get_prev_register (this_frame, cache->saved_regs, prev_regnum); } static frame_unwind arm_prologue_unwind = { "arm prologue", NORMAL_FRAME, arm_prologue_unwind_stop_reason, arm_prologue_this_id, arm_prologue_prev_register, NULL, default_frame_sniffer }; /* Maintain a list of ARM exception table entries per objfile, similar to the list of mapping symbols. We only cache entries for standard ARM-defined personality routines; the cache will contain only the frame unwinding instructions associated with the entry (not the descriptors). */ struct arm_exidx_entry { CORE_ADDR addr; gdb_byte *entry; bool operator< (const arm_exidx_entry &other) const { return addr < other.addr; } }; struct arm_exidx_data { std::vector> section_maps; }; /* Per-BFD key to store exception handling information. */ static const registry::key arm_exidx_data_key; static struct obj_section * arm_obj_section_from_vma (struct objfile *objfile, bfd_vma vma) { for (obj_section *osect : objfile->sections ()) if (bfd_section_flags (osect->the_bfd_section) & SEC_ALLOC) { bfd_vma start, size; start = bfd_section_vma (osect->the_bfd_section); size = bfd_section_size (osect->the_bfd_section); if (start <= vma && vma < start + size) return osect; } return NULL; } /* Parse contents of exception table and exception index sections of OBJFILE, and fill in the exception table entry cache. For each entry that refers to a standard ARM-defined personality routine, extract the frame unwinding instructions (from either the index or the table section). The unwinding instructions are normalized by: - extracting them from the rest of the table data - converting to host endianness - appending the implicit 0xb0 ("Finish") code The extracted and normalized instructions are stored for later retrieval by the arm_find_exidx_entry routine. */ static void arm_exidx_new_objfile (struct objfile *objfile) { struct arm_exidx_data *data; asection *exidx, *extab; bfd_vma exidx_vma = 0, extab_vma = 0; LONGEST i; /* If we've already touched this file, do nothing. */ if (!objfile || arm_exidx_data_key.get (objfile->obfd.get ()) != NULL) return; /* Read contents of exception table and index. */ exidx = bfd_get_section_by_name (objfile->obfd.get (), ELF_STRING_ARM_unwind); gdb::byte_vector exidx_data; if (exidx) { exidx_vma = bfd_section_vma (exidx); exidx_data.resize (bfd_section_size (exidx)); if (!bfd_get_section_contents (objfile->obfd.get (), exidx, exidx_data.data (), 0, exidx_data.size ())) return; } extab = bfd_get_section_by_name (objfile->obfd.get (), ".ARM.extab"); gdb::byte_vector extab_data; if (extab) { extab_vma = bfd_section_vma (extab); extab_data.resize (bfd_section_size (extab)); if (!bfd_get_section_contents (objfile->obfd.get (), extab, extab_data.data (), 0, extab_data.size ())) return; } /* Allocate exception table data structure. */ data = arm_exidx_data_key.emplace (objfile->obfd.get ()); data->section_maps.resize (objfile->obfd->section_count); /* Fill in exception table. */ for (i = 0; i < exidx_data.size () / 8; i++) { struct arm_exidx_entry new_exidx_entry; bfd_vma idx = bfd_h_get_32 (objfile->obfd, exidx_data.data () + i * 8); bfd_vma val = bfd_h_get_32 (objfile->obfd, exidx_data.data () + i * 8 + 4); bfd_vma addr = 0, word = 0; int n_bytes = 0, n_words = 0; struct obj_section *sec; gdb_byte *entry = NULL; /* Extract address of start of function. */ idx = ((idx & 0x7fffffff) ^ 0x40000000) - 0x40000000; idx += exidx_vma + i * 8; /* Find section containing function and compute section offset. */ sec = arm_obj_section_from_vma (objfile, idx); if (sec == NULL) continue; idx -= bfd_section_vma (sec->the_bfd_section); /* Determine address of exception table entry. */ if (val == 1) { /* EXIDX_CANTUNWIND -- no exception table entry present. */ } else if ((val & 0xff000000) == 0x80000000) { /* Exception table entry embedded in .ARM.exidx -- must be short form. */ word = val; n_bytes = 3; } else if (!(val & 0x80000000)) { /* Exception table entry in .ARM.extab. */ addr = ((val & 0x7fffffff) ^ 0x40000000) - 0x40000000; addr += exidx_vma + i * 8 + 4; if (addr >= extab_vma && addr + 4 <= extab_vma + extab_data.size ()) { word = bfd_h_get_32 (objfile->obfd, extab_data.data () + addr - extab_vma); addr += 4; if ((word & 0xff000000) == 0x80000000) { /* Short form. */ n_bytes = 3; } else if ((word & 0xff000000) == 0x81000000 || (word & 0xff000000) == 0x82000000) { /* Long form. */ n_bytes = 2; n_words = ((word >> 16) & 0xff); } else if (!(word & 0x80000000)) { bfd_vma pers; struct obj_section *pers_sec; int gnu_personality = 0; /* Custom personality routine. */ pers = ((word & 0x7fffffff) ^ 0x40000000) - 0x40000000; pers = UNMAKE_THUMB_ADDR (pers + addr - 4); /* Check whether we've got one of the variants of the GNU personality routines. */ pers_sec = arm_obj_section_from_vma (objfile, pers); if (pers_sec) { static const char *personality[] = { "__gcc_personality_v0", "__gxx_personality_v0", "__gcj_personality_v0", "__gnu_objc_personality_v0", NULL }; CORE_ADDR pc = pers + pers_sec->offset (); int k; for (k = 0; personality[k]; k++) if (lookup_minimal_symbol_by_pc_name (pc, personality[k], objfile)) { gnu_personality = 1; break; } } /* If so, the next word contains a word count in the high byte, followed by the same unwind instructions as the pre-defined forms. */ if (gnu_personality && addr + 4 <= extab_vma + extab_data.size ()) { word = bfd_h_get_32 (objfile->obfd, (extab_data.data () + addr - extab_vma)); addr += 4; n_bytes = 3; n_words = ((word >> 24) & 0xff); } } } } /* Sanity check address. */ if (n_words) if (addr < extab_vma || addr + 4 * n_words > extab_vma + extab_data.size ()) n_words = n_bytes = 0; /* The unwind instructions reside in WORD (only the N_BYTES least significant bytes are valid), followed by N_WORDS words in the extab section starting at ADDR. */ if (n_bytes || n_words) { gdb_byte *p = entry = (gdb_byte *) obstack_alloc (&objfile->objfile_obstack, n_bytes + n_words * 4 + 1); while (n_bytes--) *p++ = (gdb_byte) ((word >> (8 * n_bytes)) & 0xff); while (n_words--) { word = bfd_h_get_32 (objfile->obfd, extab_data.data () + addr - extab_vma); addr += 4; *p++ = (gdb_byte) ((word >> 24) & 0xff); *p++ = (gdb_byte) ((word >> 16) & 0xff); *p++ = (gdb_byte) ((word >> 8) & 0xff); *p++ = (gdb_byte) (word & 0xff); } /* Implied "Finish" to terminate the list. */ *p++ = 0xb0; } /* Push entry onto vector. They are guaranteed to always appear in order of increasing addresses. */ new_exidx_entry.addr = idx; new_exidx_entry.entry = entry; data->section_maps[sec->the_bfd_section->index].push_back (new_exidx_entry); } } /* Search for the exception table entry covering MEMADDR. If one is found, return a pointer to its data. Otherwise, return 0. If START is non-NULL, set *START to the start of the region covered by this entry. */ static gdb_byte * arm_find_exidx_entry (CORE_ADDR memaddr, CORE_ADDR *start) { struct obj_section *sec; sec = find_pc_section (memaddr); if (sec != NULL) { struct arm_exidx_data *data; struct arm_exidx_entry map_key = { memaddr - sec->addr (), 0 }; data = arm_exidx_data_key.get (sec->objfile->obfd.get ()); if (data != NULL) { std::vector &map = data->section_maps[sec->the_bfd_section->index]; if (!map.empty ()) { auto idx = std::lower_bound (map.begin (), map.end (), map_key); /* std::lower_bound finds the earliest ordered insertion point. If the following symbol starts at this exact address, we use that; otherwise, the preceding exception table entry covers this address. */ if (idx < map.end ()) { if (idx->addr == map_key.addr) { if (start) *start = idx->addr + sec->addr (); return idx->entry; } } if (idx > map.begin ()) { idx = idx - 1; if (start) *start = idx->addr + sec->addr (); return idx->entry; } } } } return NULL; } /* Given the current frame THIS_FRAME, and its associated frame unwinding instruction list from the ARM exception table entry ENTRY, allocate and return a prologue cache structure describing how to unwind this frame. Return NULL if the unwinding instruction list contains a "spare", "reserved" or "refuse to unwind" instruction as defined in section "9.3 Frame unwinding instructions" of the "Exception Handling ABI for the ARM Architecture" document. */ static struct arm_prologue_cache * arm_exidx_fill_cache (frame_info_ptr this_frame, gdb_byte *entry) { CORE_ADDR vsp = 0; int vsp_valid = 0; struct arm_prologue_cache *cache; cache = FRAME_OBSTACK_ZALLOC (struct arm_prologue_cache); arm_cache_init (cache, this_frame); for (;;) { gdb_byte insn; /* Whenever we reload SP, we actually have to retrieve its actual value in the current frame. */ if (!vsp_valid) { if (cache->saved_regs[ARM_SP_REGNUM].is_realreg ()) { int reg = cache->saved_regs[ARM_SP_REGNUM].realreg (); vsp = get_frame_register_unsigned (this_frame, reg); } else { CORE_ADDR addr = cache->saved_regs[ARM_SP_REGNUM].addr (); vsp = get_frame_memory_unsigned (this_frame, addr, 4); } vsp_valid = 1; } /* Decode next unwind instruction. */ insn = *entry++; if ((insn & 0xc0) == 0) { int offset = insn & 0x3f; vsp += (offset << 2) + 4; } else if ((insn & 0xc0) == 0x40) { int offset = insn & 0x3f; vsp -= (offset << 2) + 4; } else if ((insn & 0xf0) == 0x80) { int mask = ((insn & 0xf) << 8) | *entry++; int i; /* The special case of an all-zero mask identifies "Refuse to unwind". We return NULL to fall back to the prologue analyzer. */ if (mask == 0) return NULL; /* Pop registers r4..r15 under mask. */ for (i = 0; i < 12; i++) if (mask & (1 << i)) { cache->saved_regs[4 + i].set_addr (vsp); vsp += 4; } /* Special-case popping SP -- we need to reload vsp. */ if (mask & (1 << (ARM_SP_REGNUM - 4))) vsp_valid = 0; } else if ((insn & 0xf0) == 0x90) { int reg = insn & 0xf; /* Reserved cases. */ if (reg == ARM_SP_REGNUM || reg == ARM_PC_REGNUM) return NULL; /* Set SP from another register and mark VSP for reload. */ cache->saved_regs[ARM_SP_REGNUM] = cache->saved_regs[reg]; vsp_valid = 0; } else if ((insn & 0xf0) == 0xa0) { int count = insn & 0x7; int pop_lr = (insn & 0x8) != 0; int i; /* Pop r4..r[4+count]. */ for (i = 0; i <= count; i++) { cache->saved_regs[4 + i].set_addr (vsp); vsp += 4; } /* If indicated by flag, pop LR as well. */ if (pop_lr) { cache->saved_regs[ARM_LR_REGNUM].set_addr (vsp); vsp += 4; } } else if (insn == 0xb0) { /* We could only have updated PC by popping into it; if so, it will show up as address. Otherwise, copy LR into PC. */ if (!cache->saved_regs[ARM_PC_REGNUM].is_addr ()) cache->saved_regs[ARM_PC_REGNUM] = cache->saved_regs[ARM_LR_REGNUM]; /* We're done. */ break; } else if (insn == 0xb1) { int mask = *entry++; int i; /* All-zero mask and mask >= 16 is "spare". */ if (mask == 0 || mask >= 16) return NULL; /* Pop r0..r3 under mask. */ for (i = 0; i < 4; i++) if (mask & (1 << i)) { cache->saved_regs[i].set_addr (vsp); vsp += 4; } } else if (insn == 0xb2) { ULONGEST offset = 0; unsigned shift = 0; do { offset |= (*entry & 0x7f) << shift; shift += 7; } while (*entry++ & 0x80); vsp += 0x204 + (offset << 2); } else if (insn == 0xb3) { int start = *entry >> 4; int count = (*entry++) & 0xf; int i; /* Only registers D0..D15 are valid here. */ if (start + count >= 16) return NULL; /* Pop VFP double-precision registers D[start]..D[start+count]. */ for (i = 0; i <= count; i++) { cache->saved_regs[ARM_D0_REGNUM + start + i].set_addr (vsp); vsp += 8; } /* Add an extra 4 bytes for FSTMFDX-style stack. */ vsp += 4; } else if ((insn & 0xf8) == 0xb8) { int count = insn & 0x7; int i; /* Pop VFP double-precision registers D[8]..D[8+count]. */ for (i = 0; i <= count; i++) { cache->saved_regs[ARM_D0_REGNUM + 8 + i].set_addr (vsp); vsp += 8; } /* Add an extra 4 bytes for FSTMFDX-style stack. */ vsp += 4; } else if (insn == 0xc6) { int start = *entry >> 4; int count = (*entry++) & 0xf; int i; /* Only registers WR0..WR15 are valid. */ if (start + count >= 16) return NULL; /* Pop iwmmx registers WR[start]..WR[start+count]. */ for (i = 0; i <= count; i++) { cache->saved_regs[ARM_WR0_REGNUM + start + i].set_addr (vsp); vsp += 8; } } else if (insn == 0xc7) { int mask = *entry++; int i; /* All-zero mask and mask >= 16 is "spare". */ if (mask == 0 || mask >= 16) return NULL; /* Pop iwmmx general-purpose registers WCGR0..WCGR3 under mask. */ for (i = 0; i < 4; i++) if (mask & (1 << i)) { cache->saved_regs[ARM_WCGR0_REGNUM + i].set_addr (vsp); vsp += 4; } } else if ((insn & 0xf8) == 0xc0) { int count = insn & 0x7; int i; /* Pop iwmmx registers WR[10]..WR[10+count]. */ for (i = 0; i <= count; i++) { cache->saved_regs[ARM_WR0_REGNUM + 10 + i].set_addr (vsp); vsp += 8; } } else if (insn == 0xc8) { int start = *entry >> 4; int count = (*entry++) & 0xf; int i; /* Only registers D0..D31 are valid. */ if (start + count >= 16) return NULL; /* Pop VFP double-precision registers D[16+start]..D[16+start+count]. */ for (i = 0; i <= count; i++) { cache->saved_regs[ARM_D0_REGNUM + 16 + start + i].set_addr (vsp); vsp += 8; } } else if (insn == 0xc9) { int start = *entry >> 4; int count = (*entry++) & 0xf; int i; /* Pop VFP double-precision registers D[start]..D[start+count]. */ for (i = 0; i <= count; i++) { cache->saved_regs[ARM_D0_REGNUM + start + i].set_addr (vsp); vsp += 8; } } else if ((insn & 0xf8) == 0xd0) { int count = insn & 0x7; int i; /* Pop VFP double-precision registers D[8]..D[8+count]. */ for (i = 0; i <= count; i++) { cache->saved_regs[ARM_D0_REGNUM + 8 + i].set_addr (vsp); vsp += 8; } } else { /* Everything else is "spare". */ return NULL; } } /* If we restore SP from a register, assume this was the frame register. Otherwise just fall back to SP as frame register. */ if (cache->saved_regs[ARM_SP_REGNUM].is_realreg ()) cache->framereg = cache->saved_regs[ARM_SP_REGNUM].realreg (); else cache->framereg = ARM_SP_REGNUM; /* Determine offset to previous frame. */ cache->framesize = vsp - get_frame_register_unsigned (this_frame, cache->framereg); /* We already got the previous SP. */ arm_gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (this_frame)); arm_cache_set_active_sp_value (cache, tdep, vsp); return cache; } /* Unwinding via ARM exception table entries. Note that the sniffer already computes a filled-in prologue cache, which is then used with the same arm_prologue_this_id and arm_prologue_prev_register routines also used for prologue-parsing based unwinding. */ static int arm_exidx_unwind_sniffer (const struct frame_unwind *self, frame_info_ptr this_frame, void **this_prologue_cache) { struct gdbarch *gdbarch = get_frame_arch (this_frame); enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch); CORE_ADDR addr_in_block, exidx_region, func_start; struct arm_prologue_cache *cache; gdb_byte *entry; /* See if we have an ARM exception table entry covering this address. */ addr_in_block = get_frame_address_in_block (this_frame); entry = arm_find_exidx_entry (addr_in_block, &exidx_region); if (!entry) return 0; /* The ARM exception table does not describe unwind information for arbitrary PC values, but is guaranteed to be correct only at call sites. We have to decide here whether we want to use ARM exception table information for this frame, or fall back to using prologue parsing. (Note that if we have DWARF CFI, this sniffer isn't even called -- CFI is always preferred.) Before we make this decision, however, we check whether we actually have *symbol* information for the current frame. If not, prologue parsing would not work anyway, so we might as well use the exception table and hope for the best. */ if (find_pc_partial_function (addr_in_block, NULL, &func_start, NULL)) { int exc_valid = 0; /* If the next frame is "normal", we are at a call site in this frame, so exception information is guaranteed to be valid. */ if (get_next_frame (this_frame) && get_frame_type (get_next_frame (this_frame)) == NORMAL_FRAME) exc_valid = 1; /* Some syscalls keep PC pointing to the SVC instruction itself. */ for (int shift = 0; shift <= 1 && !exc_valid; ++shift) { /* We also assume exception information is valid if we're currently blocked in a system call. The system library is supposed to ensure this, so that e.g. pthread cancellation works. */ if (arm_frame_is_thumb (this_frame)) { ULONGEST insn; if (safe_read_memory_unsigned_integer ((get_frame_pc (this_frame) - (shift ? 2 : 0)), 2, byte_order_for_code, &insn) && (insn & 0xff00) == 0xdf00 /* svc */) exc_valid = 1; } else { ULONGEST insn; if (safe_read_memory_unsigned_integer ((get_frame_pc (this_frame) - (shift ? 4 : 0)), 4, byte_order_for_code, &insn) && (insn & 0x0f000000) == 0x0f000000 /* svc */) exc_valid = 1; } } /* Bail out if we don't know that exception information is valid. */ if (!exc_valid) return 0; /* The ARM exception index does not mark the *end* of the region covered by the entry, and some functions will not have any entry. To correctly recognize the end of the covered region, the linker should have inserted dummy records with a CANTUNWIND marker. Unfortunately, current versions of GNU ld do not reliably do this, and thus we may have found an incorrect entry above. As a (temporary) sanity check, we only use the entry if it lies *within* the bounds of the function. Note that this check might reject perfectly valid entries that just happen to cover multiple functions; therefore this check ought to be removed once the linker is fixed. */ if (func_start > exidx_region) return 0; } /* Decode the list of unwinding instructions into a prologue cache. Note that this may fail due to e.g. a "refuse to unwind" code. */ cache = arm_exidx_fill_cache (this_frame, entry); if (!cache) return 0; *this_prologue_cache = cache; return 1; } struct frame_unwind arm_exidx_unwind = { "arm exidx", NORMAL_FRAME, default_frame_unwind_stop_reason, arm_prologue_this_id, arm_prologue_prev_register, NULL, arm_exidx_unwind_sniffer }; static struct arm_prologue_cache * arm_make_epilogue_frame_cache (frame_info_ptr this_frame) { struct arm_prologue_cache *cache; int reg; cache = FRAME_OBSTACK_ZALLOC (struct arm_prologue_cache); arm_cache_init (cache, this_frame); /* Still rely on the offset calculated from prologue. */ arm_scan_prologue (this_frame, cache); /* Since we are in epilogue, the SP has been restored. */ arm_gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (this_frame)); arm_cache_set_active_sp_value (cache, tdep, get_frame_register_unsigned (this_frame, ARM_SP_REGNUM)); /* Calculate actual addresses of saved registers using offsets determined by arm_scan_prologue. */ for (reg = 0; reg < gdbarch_num_regs (get_frame_arch (this_frame)); reg++) if (cache->saved_regs[reg].is_addr ()) cache->saved_regs[reg].set_addr (cache->saved_regs[reg].addr () + arm_cache_get_prev_sp_value (cache, tdep)); return cache; } /* Implementation of function hook 'this_id' in 'struct frame_uwnind' for epilogue unwinder. */ static void arm_epilogue_frame_this_id (frame_info_ptr this_frame, void **this_cache, struct frame_id *this_id) { struct arm_prologue_cache *cache; CORE_ADDR pc, func; if (*this_cache == NULL) *this_cache = arm_make_epilogue_frame_cache (this_frame); cache = (struct arm_prologue_cache *) *this_cache; /* Use function start address as part of the frame ID. If we cannot identify the start address (due to missing symbol information), fall back to just using the current PC. */ pc = get_frame_pc (this_frame); func = get_frame_func (this_frame); if (func == 0) func = pc; arm_gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (this_frame)); *this_id = frame_id_build (arm_cache_get_prev_sp_value (cache, tdep), pc); } /* Implementation of function hook 'prev_register' in 'struct frame_uwnind' for epilogue unwinder. */ static struct value * arm_epilogue_frame_prev_register (frame_info_ptr this_frame, void **this_cache, int regnum) { if (*this_cache == NULL) *this_cache = arm_make_epilogue_frame_cache (this_frame); return arm_prologue_prev_register (this_frame, this_cache, regnum); } static int arm_stack_frame_destroyed_p_1 (struct gdbarch *gdbarch, CORE_ADDR pc); static int thumb_stack_frame_destroyed_p (struct gdbarch *gdbarch, CORE_ADDR pc); /* Implementation of function hook 'sniffer' in 'struct frame_uwnind' for epilogue unwinder. */ static int arm_epilogue_frame_sniffer (const struct frame_unwind *self, frame_info_ptr this_frame, void **this_prologue_cache) { if (frame_relative_level (this_frame) == 0) { struct gdbarch *gdbarch = get_frame_arch (this_frame); CORE_ADDR pc = get_frame_pc (this_frame); if (arm_frame_is_thumb (this_frame)) return thumb_stack_frame_destroyed_p (gdbarch, pc); else return arm_stack_frame_destroyed_p_1 (gdbarch, pc); } else return 0; } /* Frame unwinder from epilogue. */ static const struct frame_unwind arm_epilogue_frame_unwind = { "arm epilogue", NORMAL_FRAME, default_frame_unwind_stop_reason, arm_epilogue_frame_this_id, arm_epilogue_frame_prev_register, NULL, arm_epilogue_frame_sniffer, }; /* Recognize GCC's trampoline for thumb call-indirect. If we are in a trampoline, return the target PC. Otherwise return 0. void call0a (char c, short s, int i, long l) {} int main (void) { (*pointer_to_call0a) (c, s, i, l); } Instead of calling a stub library function _call_via_xx (xx is the register name), GCC may inline the trampoline in the object file as below (register r2 has the address of call0a). .global main .type main, %function ... bl .L1 ... .size main, .-main .L1: bx r2 The trampoline 'bx r2' doesn't belong to main. */ static CORE_ADDR arm_skip_bx_reg (frame_info_ptr frame, CORE_ADDR pc) { /* The heuristics of recognizing such trampoline is that FRAME is executing in Thumb mode and the instruction on PC is 'bx Rm'. */ if (arm_frame_is_thumb (frame)) { gdb_byte buf[2]; if (target_read_memory (pc, buf, 2) == 0) { struct gdbarch *gdbarch = get_frame_arch (frame); enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch); uint16_t insn = extract_unsigned_integer (buf, 2, byte_order_for_code); if ((insn & 0xff80) == 0x4700) /* bx */ { CORE_ADDR dest = get_frame_register_unsigned (frame, bits (insn, 3, 6)); /* Clear the LSB so that gdb core sets step-resume breakpoint at the right address. */ return UNMAKE_THUMB_ADDR (dest); } } } return 0; } static struct arm_prologue_cache * arm_make_stub_cache (frame_info_ptr this_frame) { struct arm_prologue_cache *cache; cache = FRAME_OBSTACK_ZALLOC (struct arm_prologue_cache); arm_cache_init (cache, this_frame); arm_gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (this_frame)); arm_cache_set_active_sp_value (cache, tdep, get_frame_register_unsigned (this_frame, ARM_SP_REGNUM)); return cache; } /* Our frame ID for a stub frame is the current SP and LR. */ static void arm_stub_this_id (frame_info_ptr this_frame, void **this_cache, struct frame_id *this_id) { struct arm_prologue_cache *cache; if (*this_cache == NULL) *this_cache = arm_make_stub_cache (this_frame); cache = (struct arm_prologue_cache *) *this_cache; arm_gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (this_frame)); *this_id = frame_id_build (arm_cache_get_prev_sp_value (cache, tdep), get_frame_pc (this_frame)); } static int arm_stub_unwind_sniffer (const struct frame_unwind *self, frame_info_ptr this_frame, void **this_prologue_cache) { CORE_ADDR addr_in_block; gdb_byte dummy[4]; CORE_ADDR pc, start_addr; const char *name; addr_in_block = get_frame_address_in_block (this_frame); pc = get_frame_pc (this_frame); if (in_plt_section (addr_in_block) /* We also use the stub winder if the target memory is unreadable to avoid having the prologue unwinder trying to read it. */ || target_read_memory (pc, dummy, 4) != 0) return 1; if (find_pc_partial_function (pc, &name, &start_addr, NULL) == 0 && arm_skip_bx_reg (this_frame, pc) != 0) return 1; return 0; } struct frame_unwind arm_stub_unwind = { "arm stub", NORMAL_FRAME, default_frame_unwind_stop_reason, arm_stub_this_id, arm_prologue_prev_register, NULL, arm_stub_unwind_sniffer }; /* Put here the code to store, into CACHE->saved_regs, the addresses of the saved registers of frame described by THIS_FRAME. CACHE is returned. */ static struct arm_prologue_cache * arm_m_exception_cache (frame_info_ptr this_frame) { struct gdbarch *gdbarch = get_frame_arch (this_frame); arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); struct arm_prologue_cache *cache; cache = FRAME_OBSTACK_ZALLOC (struct arm_prologue_cache); arm_cache_init (cache, this_frame); /* ARMv7-M Architecture Reference "B1.5.6 Exception entry behavior" describes which bits in LR that define which stack was used prior to the exception and if FPU is used (causing extended stack frame). */ /* In the lockup state PC contains a lockup magic value. The PC value of the the next outer frame is irreversibly lost. The other registers are intact so LR likely contains PC of some frame next to the outer one, but we cannot analyze the next outer frame without knowing its PC therefore we do not know SP fixup for this frame. Some heuristics to resynchronize SP might be possible. For simplicity, just terminate the unwinding to prevent it going astray and attempting to read data/addresses it shouldn't, which may cause further issues due to side-effects. */ CORE_ADDR pc = get_frame_pc (this_frame); if (arm_m_addr_is_lockup (pc)) { /* The lockup can be real just in the innermost frame as the CPU is stopped and cannot create more frames. If we hit lockup magic PC in the other frame, it is just a sentinel at the top of stack: do not warn then. */ if (frame_relative_level (this_frame) == 0) warning (_("ARM M in lockup state, stack unwinding terminated.")); /* Terminate any further stack unwinding. */ arm_cache_set_active_sp_value (cache, tdep, 0); return cache; } CORE_ADDR lr = get_frame_register_unsigned (this_frame, ARM_LR_REGNUM); /* ARMv7-M Architecture Reference "A2.3.1 Arm core registers" states that LR is set to 0xffffffff on reset. ARMv8-M Architecture Reference "B3.3 Registers" states that LR is set to 0xffffffff on warm reset if Main Extension is implemented, otherwise the value is unknown. */ if (lr == 0xffffffff) { /* Terminate any further stack unwinding. */ arm_cache_set_active_sp_value (cache, tdep, 0); return cache; } /* Check FNC_RETURN indicator bits (24-31). */ bool fnc_return = (((lr >> 24) & 0xff) == 0xfe); if (fnc_return) { /* FNC_RETURN is only valid for targets with Security Extension. */ if (!tdep->have_sec_ext) { error (_("While unwinding an exception frame, found unexpected Link " "Register value %s that requires the security extension, " "but the extension was not found or is disabled. This " "should not happen and may be caused by corrupt data or a " "bug in GDB."), phex (lr, ARM_INT_REGISTER_SIZE)); } if (!arm_unwind_secure_frames) { warning (_("Non-secure to secure stack unwinding disabled.")); /* Terminate any further stack unwinding. */ arm_cache_set_active_sp_value (cache, tdep, 0); return cache; } ULONGEST xpsr = get_frame_register_unsigned (this_frame, ARM_PS_REGNUM); if ((xpsr & 0x1ff) != 0) /* Handler mode: This is the mode that exceptions are handled in. */ arm_cache_switch_prev_sp (cache, tdep, tdep->m_profile_msp_s_regnum); else /* Thread mode: This is the normal mode that programs run in. */ arm_cache_switch_prev_sp (cache, tdep, tdep->m_profile_psp_s_regnum); CORE_ADDR unwound_sp = arm_cache_get_prev_sp_value (cache, tdep); /* Stack layout for a function call from Secure to Non-Secure state (ARMv8-M section B3.16): SP Offset +-------------------+ 0x08 | | +-------------------+ <-- Original SP 0x04 | Partial xPSR | +-------------------+ 0x00 | Return Address | +===================+ <-- New SP */ cache->saved_regs[ARM_PC_REGNUM].set_addr (unwound_sp + 0x00); cache->saved_regs[ARM_LR_REGNUM].set_addr (unwound_sp + 0x00); cache->saved_regs[ARM_PS_REGNUM].set_addr (unwound_sp + 0x04); arm_cache_set_active_sp_value (cache, tdep, unwound_sp + 0x08); return cache; } /* Check EXC_RETURN indicator bits (24-31). */ bool exc_return = (((lr >> 24) & 0xff) == 0xff); if (exc_return) { int sp_regnum; bool secure_stack_used = false; bool default_callee_register_stacking = false; bool exception_domain_is_secure = false; enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); /* Check EXC_RETURN bit SPSEL if Main or Thread (process) stack used. */ bool process_stack_used = (bit (lr, 2) != 0); if (tdep->have_sec_ext) { secure_stack_used = (bit (lr, 6) != 0); default_callee_register_stacking = (bit (lr, 5) != 0); exception_domain_is_secure = (bit (lr, 0) != 0); /* Unwinding from non-secure to secure can trip security measures. In order to avoid the debugger being intrusive, rely on the user to configure the requested mode. */ if (secure_stack_used && !exception_domain_is_secure && !arm_unwind_secure_frames) { warning (_("Non-secure to secure stack unwinding disabled.")); /* Terminate any further stack unwinding. */ arm_cache_set_active_sp_value (cache, tdep, 0); return cache; } if (process_stack_used) { if (secure_stack_used) /* Secure thread (process) stack used, use PSP_S as SP. */ sp_regnum = tdep->m_profile_psp_s_regnum; else /* Non-secure thread (process) stack used, use PSP_NS as SP. */ sp_regnum = tdep->m_profile_psp_ns_regnum; } else { if (secure_stack_used) /* Secure main stack used, use MSP_S as SP. */ sp_regnum = tdep->m_profile_msp_s_regnum; else /* Non-secure main stack used, use MSP_NS as SP. */ sp_regnum = tdep->m_profile_msp_ns_regnum; } } else { if (process_stack_used) /* Thread (process) stack used, use PSP as SP. */ sp_regnum = tdep->m_profile_psp_regnum; else /* Main stack used, use MSP as SP. */ sp_regnum = tdep->m_profile_msp_regnum; } /* Set the active SP regnum. */ arm_cache_switch_prev_sp (cache, tdep, sp_regnum); /* Fetch the SP to use for this frame. */ CORE_ADDR unwound_sp = arm_cache_get_prev_sp_value (cache, tdep); /* Exception entry context stacking are described in ARMv8-M (section B3.19) and ARMv7-M (sections B1.5.6 and B1.5.7) Architecture Reference Manuals. The following figure shows the structure of the stack frame when Security and Floating-point extensions are present. SP Offsets Without With Callee Regs Callee Regs (Secure -> Non-Secure) +-------------------+ 0xA8 | | 0xD0 +===================+ --+ <-- Original SP 0xA4 | S31 | 0xCC | +-------------------+ | ... | Additional FP context +-------------------+ | 0x68 | S16 | 0x90 | +===================+ --+ 0x64 | Reserved | 0x8C | +-------------------+ | 0x60 | FPSCR | 0x88 | +-------------------+ | 0x5C | S15 | 0x84 | FP context +-------------------+ | ... | +-------------------+ | 0x20 | S0 | 0x48 | +===================+ --+ 0x1C | xPSR | 0x44 | +-------------------+ | 0x18 | Return address | 0x40 | +-------------------+ | 0x14 | LR(R14) | 0x3C | +-------------------+ | 0x10 | R12 | 0x38 | State context +-------------------+ | 0x0C | R3 | 0x34 | +-------------------+ | ... | +-------------------+ | 0x00 | R0 | 0x28 | +===================+ --+ | R11 | 0x24 | +-------------------+ | ... | +-------------------+ | Additional state | R4 | 0x08 | context when +-------------------+ | transitioning from | Reserved | 0x04 | Secure to Non-Secure +-------------------+ | | Magic signature | 0x00 | +===================+ --+ <-- New SP */ uint32_t sp_r0_offset = 0; /* With the Security extension, the hardware saves R4..R11 too. */ if (tdep->have_sec_ext && secure_stack_used && (!default_callee_register_stacking || !exception_domain_is_secure)) { /* Read R4..R11 from the integer callee registers. */ cache->saved_regs[4].set_addr (unwound_sp + 0x08); cache->saved_regs[5].set_addr (unwound_sp + 0x0C); cache->saved_regs[6].set_addr (unwound_sp + 0x10); cache->saved_regs[7].set_addr (unwound_sp + 0x14); cache->saved_regs[8].set_addr (unwound_sp + 0x18); cache->saved_regs[9].set_addr (unwound_sp + 0x1C); cache->saved_regs[10].set_addr (unwound_sp + 0x20); cache->saved_regs[11].set_addr (unwound_sp + 0x24); sp_r0_offset = 0x28; } /* The hardware saves eight 32-bit words, comprising xPSR, ReturnAddress, LR (R14), R12, R3, R2, R1, R0. See details in "B1.5.6 Exception entry behavior" in "ARMv7-M Architecture Reference Manual". */ cache->saved_regs[0].set_addr (unwound_sp + sp_r0_offset); cache->saved_regs[1].set_addr (unwound_sp + sp_r0_offset + 0x04); cache->saved_regs[2].set_addr (unwound_sp + sp_r0_offset + 0x08); cache->saved_regs[3].set_addr (unwound_sp + sp_r0_offset + 0x0C); cache->saved_regs[ARM_IP_REGNUM].set_addr (unwound_sp + sp_r0_offset + 0x10); cache->saved_regs[ARM_LR_REGNUM].set_addr (unwound_sp + sp_r0_offset + 0x14); cache->saved_regs[ARM_PC_REGNUM].set_addr (unwound_sp + sp_r0_offset + 0x18); cache->saved_regs[ARM_PS_REGNUM].set_addr (unwound_sp + sp_r0_offset + 0x1C); /* Check EXC_RETURN bit FTYPE if extended stack frame (FPU regs stored) type used. */ bool extended_frame_used = (bit (lr, 4) == 0); if (extended_frame_used) { ULONGEST fpccr; ULONGEST fpcar; /* Read FPCCR register. */ if (!safe_read_memory_unsigned_integer (FPCCR, ARM_INT_REGISTER_SIZE, byte_order, &fpccr)) { warning (_("Could not fetch required FPCCR content. Further " "unwinding is impossible.")); arm_cache_set_active_sp_value (cache, tdep, 0); return cache; } /* Read FPCAR register. */ if (!safe_read_memory_unsigned_integer (FPCAR, ARM_INT_REGISTER_SIZE, byte_order, &fpcar)) { warning (_("Could not fetch FPCAR content. Further unwinding of " "FP register values will be unreliable.")); fpcar = 0; } bool fpccr_aspen = bit (fpccr, 31); bool fpccr_lspen = bit (fpccr, 30); bool fpccr_ts = bit (fpccr, 26); bool fpccr_lspact = bit (fpccr, 0); /* The LSPEN and ASPEN bits indicate if the lazy state preservation for FP registers is enabled or disabled. The LSPACT bit indicate, together with FPCAR, if the lazy state preservation feature is active for the current frame or for another frame. See "Lazy context save of FP state", in B1.5.7, also ARM AN298, supported by Cortex-M4F architecture for details. */ bool fpcar_points_to_this_frame = ((unwound_sp + sp_r0_offset + 0x20) == (fpcar & ~0x7)); bool read_fp_regs_from_stack = (!(fpccr_aspen && fpccr_lspen && fpccr_lspact && fpcar_points_to_this_frame)); /* Extended stack frame type used. */ if (read_fp_regs_from_stack) { CORE_ADDR addr = unwound_sp + sp_r0_offset + 0x20; for (int i = 0; i < 8; i++) { cache->saved_regs[ARM_D0_REGNUM + i].set_addr (addr); addr += 8; } } cache->saved_regs[ARM_FPSCR_REGNUM].set_addr (unwound_sp + sp_r0_offset + 0x60); if (tdep->have_sec_ext && !default_callee_register_stacking && fpccr_ts) { /* Handle floating-point callee saved registers. */ if (read_fp_regs_from_stack) { CORE_ADDR addr = unwound_sp + sp_r0_offset + 0x68; for (int i = 8; i < 16; i++) { cache->saved_regs[ARM_D0_REGNUM + i].set_addr (addr); addr += 8; } } arm_cache_set_active_sp_value (cache, tdep, unwound_sp + sp_r0_offset + 0xA8); } else { /* Offset 0x64 is reserved. */ arm_cache_set_active_sp_value (cache, tdep, unwound_sp + sp_r0_offset + 0x68); } } else { /* Standard stack frame type used. */ arm_cache_set_active_sp_value (cache, tdep, unwound_sp + sp_r0_offset + 0x20); } /* If bit 9 of the saved xPSR is set, then there is a four-byte aligner between the top of the 32-byte stack frame and the previous context's stack pointer. */ ULONGEST xpsr; if (!safe_read_memory_unsigned_integer (cache->saved_regs[ARM_PS_REGNUM] .addr (), ARM_INT_REGISTER_SIZE, byte_order, &xpsr)) { warning (_("Could not fetch required XPSR content. Further " "unwinding is impossible.")); arm_cache_set_active_sp_value (cache, tdep, 0); return cache; } if (bit (xpsr, 9) != 0) { CORE_ADDR new_sp = arm_cache_get_prev_sp_value (cache, tdep) + 4; arm_cache_set_active_sp_value (cache, tdep, new_sp); } return cache; } internal_error (_("While unwinding an exception frame, " "found unexpected Link Register value " "%s. This should not happen and may " "be caused by corrupt data or a bug in" " GDB."), phex (lr, ARM_INT_REGISTER_SIZE)); } /* Implementation of the stop_reason hook for arm_m_exception frames. */ static enum unwind_stop_reason arm_m_exception_frame_unwind_stop_reason (frame_info_ptr this_frame, void **this_cache) { struct arm_prologue_cache *cache; arm_gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (this_frame)); if (*this_cache == NULL) *this_cache = arm_m_exception_cache (this_frame); cache = (struct arm_prologue_cache *) *this_cache; /* If we've hit a wall, stop. */ if (arm_cache_get_prev_sp_value (cache, tdep) == 0) return UNWIND_OUTERMOST; return UNWIND_NO_REASON; } /* Implementation of function hook 'this_id' in 'struct frame_uwnind'. */ static void arm_m_exception_this_id (frame_info_ptr this_frame, void **this_cache, struct frame_id *this_id) { struct arm_prologue_cache *cache; if (*this_cache == NULL) *this_cache = arm_m_exception_cache (this_frame); cache = (struct arm_prologue_cache *) *this_cache; /* Our frame ID for a stub frame is the current SP and LR. */ arm_gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (this_frame)); *this_id = frame_id_build (arm_cache_get_prev_sp_value (cache, tdep), get_frame_pc (this_frame)); } /* Implementation of function hook 'prev_register' in 'struct frame_uwnind'. */ static struct value * arm_m_exception_prev_register (frame_info_ptr this_frame, void **this_cache, int prev_regnum) { struct arm_prologue_cache *cache; CORE_ADDR sp_value; if (*this_cache == NULL) *this_cache = arm_m_exception_cache (this_frame); cache = (struct arm_prologue_cache *) *this_cache; /* The value was already reconstructed into PREV_SP. */ arm_gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (this_frame)); if (prev_regnum == ARM_SP_REGNUM) return frame_unwind_got_constant (this_frame, prev_regnum, arm_cache_get_prev_sp_value (cache, tdep)); /* If we are asked to unwind the PC, strip the saved T bit. */ if (prev_regnum == ARM_PC_REGNUM) { struct value *value = trad_frame_get_prev_register (this_frame, cache->saved_regs, prev_regnum); CORE_ADDR pc = value_as_address (value); return frame_unwind_got_constant (this_frame, prev_regnum, UNMAKE_THUMB_ADDR (pc)); } /* The value might be one of the alternative SP, if so, use the value already constructed. */ if (arm_is_alternative_sp_register (tdep, prev_regnum)) { sp_value = arm_cache_get_sp_register (cache, tdep, prev_regnum); return frame_unwind_got_constant (this_frame, prev_regnum, sp_value); } /* If we are asked to unwind the xPSR, set T bit if PC is in thumb mode. LR register is unreliable as it contains FNC_RETURN or EXC_RETURN pattern. */ if (prev_regnum == ARM_PS_REGNUM) { struct gdbarch *gdbarch = get_frame_arch (this_frame); struct value *value = trad_frame_get_prev_register (this_frame, cache->saved_regs, ARM_PC_REGNUM); CORE_ADDR pc = value_as_address (value); value = trad_frame_get_prev_register (this_frame, cache->saved_regs, ARM_PS_REGNUM); ULONGEST xpsr = value_as_long (value); /* Reconstruct the T bit; see arm_prologue_prev_register for details. */ xpsr = reconstruct_t_bit (gdbarch, pc, xpsr); return frame_unwind_got_constant (this_frame, ARM_PS_REGNUM, xpsr); } return trad_frame_get_prev_register (this_frame, cache->saved_regs, prev_regnum); } /* Implementation of function hook 'sniffer' in 'struct frame_uwnind'. */ static int arm_m_exception_unwind_sniffer (const struct frame_unwind *self, frame_info_ptr this_frame, void **this_prologue_cache) { struct gdbarch *gdbarch = get_frame_arch (this_frame); CORE_ADDR this_pc = get_frame_pc (this_frame); /* No need to check is_m; this sniffer is only registered for M-profile architectures. */ /* Check if exception frame returns to a magic PC value. */ return arm_m_addr_is_magic (gdbarch, this_pc); } /* Frame unwinder for M-profile exceptions (EXC_RETURN on stack), lockup and secure/nonsecure interstate function calls (FNC_RETURN). */ struct frame_unwind arm_m_exception_unwind = { "arm m exception lockup sec_fnc", SIGTRAMP_FRAME, arm_m_exception_frame_unwind_stop_reason, arm_m_exception_this_id, arm_m_exception_prev_register, NULL, arm_m_exception_unwind_sniffer }; static CORE_ADDR arm_normal_frame_base (frame_info_ptr this_frame, void **this_cache) { struct arm_prologue_cache *cache; if (*this_cache == NULL) *this_cache = arm_make_prologue_cache (this_frame); cache = (struct arm_prologue_cache *) *this_cache; arm_gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (this_frame)); return arm_cache_get_prev_sp_value (cache, tdep) - cache->framesize; } struct frame_base arm_normal_base = { &arm_prologue_unwind, arm_normal_frame_base, arm_normal_frame_base, arm_normal_frame_base }; struct arm_dwarf2_prev_register_cache { /* Cached value of the coresponding stack pointer for the inner frame. */ CORE_ADDR sp; CORE_ADDR msp; CORE_ADDR msp_s; CORE_ADDR msp_ns; CORE_ADDR psp; CORE_ADDR psp_s; CORE_ADDR psp_ns; }; static struct value * arm_dwarf2_prev_register (frame_info_ptr this_frame, void **this_cache, int regnum) { struct gdbarch * gdbarch = get_frame_arch (this_frame); arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); CORE_ADDR lr; ULONGEST cpsr; arm_dwarf2_prev_register_cache *cache = ((arm_dwarf2_prev_register_cache *) dwarf2_frame_get_fn_data (this_frame, this_cache, arm_dwarf2_prev_register)); if (!cache) { const unsigned int size = sizeof (struct arm_dwarf2_prev_register_cache); cache = ((arm_dwarf2_prev_register_cache *) dwarf2_frame_allocate_fn_data (this_frame, this_cache, arm_dwarf2_prev_register, size)); if (tdep->have_sec_ext) { cache->sp = get_frame_register_unsigned (this_frame, ARM_SP_REGNUM); cache->msp_s = get_frame_register_unsigned (this_frame, tdep->m_profile_msp_s_regnum); cache->msp_ns = get_frame_register_unsigned (this_frame, tdep->m_profile_msp_ns_regnum); cache->psp_s = get_frame_register_unsigned (this_frame, tdep->m_profile_psp_s_regnum); cache->psp_ns = get_frame_register_unsigned (this_frame, tdep->m_profile_psp_ns_regnum); } else if (tdep->is_m) { cache->sp = get_frame_register_unsigned (this_frame, ARM_SP_REGNUM); cache->msp = get_frame_register_unsigned (this_frame, tdep->m_profile_msp_regnum); cache->psp = get_frame_register_unsigned (this_frame, tdep->m_profile_psp_regnum); } } if (regnum == ARM_PC_REGNUM) { /* The PC is normally copied from the return column, which describes saves of LR. However, that version may have an extra bit set to indicate Thumb state. The bit is not part of the PC. */ /* Record in the frame whether the return address was signed. */ if (tdep->have_pacbti) { CORE_ADDR ra_auth_code = frame_unwind_register_unsigned (this_frame, tdep->pacbti_pseudo_base); if (ra_auth_code != 0) set_frame_previous_pc_masked (this_frame); } lr = frame_unwind_register_unsigned (this_frame, ARM_LR_REGNUM); return frame_unwind_got_constant (this_frame, regnum, arm_addr_bits_remove (gdbarch, lr)); } else if (regnum == ARM_PS_REGNUM) { /* Reconstruct the T bit; see arm_prologue_prev_register for details. */ cpsr = get_frame_register_unsigned (this_frame, regnum); lr = frame_unwind_register_unsigned (this_frame, ARM_LR_REGNUM); cpsr = reconstruct_t_bit (gdbarch, lr, cpsr); return frame_unwind_got_constant (this_frame, regnum, cpsr); } else if (arm_is_alternative_sp_register (tdep, regnum)) { /* Handle the alternative SP registers on Cortex-M. */ bool override_with_sp_value = false; CORE_ADDR val; if (tdep->have_sec_ext) { bool is_msp = (regnum == tdep->m_profile_msp_regnum) && (cache->msp_s == cache->sp || cache->msp_ns == cache->sp); bool is_msp_s = (regnum == tdep->m_profile_msp_s_regnum) && (cache->msp_s == cache->sp); bool is_msp_ns = (regnum == tdep->m_profile_msp_ns_regnum) && (cache->msp_ns == cache->sp); bool is_psp = (regnum == tdep->m_profile_psp_regnum) && (cache->psp_s == cache->sp || cache->psp_ns == cache->sp); bool is_psp_s = (regnum == tdep->m_profile_psp_s_regnum) && (cache->psp_s == cache->sp); bool is_psp_ns = (regnum == tdep->m_profile_psp_ns_regnum) && (cache->psp_ns == cache->sp); override_with_sp_value = is_msp || is_msp_s || is_msp_ns || is_psp || is_psp_s || is_psp_ns; } else if (tdep->is_m) { bool is_msp = (regnum == tdep->m_profile_msp_regnum) && (cache->sp == cache->msp); bool is_psp = (regnum == tdep->m_profile_psp_regnum) && (cache->sp == cache->psp); override_with_sp_value = is_msp || is_psp; } if (override_with_sp_value) { /* Use value of SP from previous frame. */ frame_info_ptr prev_frame = get_prev_frame (this_frame); if (prev_frame) val = get_frame_register_unsigned (prev_frame, ARM_SP_REGNUM); else val = get_frame_base (this_frame); } else /* Use value for the register from previous frame. */ val = get_frame_register_unsigned (this_frame, regnum); return frame_unwind_got_constant (this_frame, regnum, val); } internal_error (_("Unexpected register %d"), regnum); } /* Implement the stack_frame_destroyed_p gdbarch method. */ static int thumb_stack_frame_destroyed_p (struct gdbarch *gdbarch, CORE_ADDR pc) { enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch); unsigned int insn, insn2; int found_return = 0, found_stack_adjust = 0; CORE_ADDR func_start, func_end; CORE_ADDR scan_pc; gdb_byte buf[4]; if (!find_pc_partial_function (pc, NULL, &func_start, &func_end)) return 0; /* The epilogue is a sequence of instructions along the following lines: - add stack frame size to SP or FP - [if frame pointer used] restore SP from FP - restore registers from SP [may include PC] - a return-type instruction [if PC wasn't already restored] In a first pass, we scan forward from the current PC and verify the instructions we find as compatible with this sequence, ending in a return instruction. However, this is not sufficient to distinguish indirect function calls within a function from indirect tail calls in the epilogue in some cases. Therefore, if we didn't already find any SP-changing instruction during forward scan, we add a backward scanning heuristic to ensure we actually are in the epilogue. */ scan_pc = pc; while (scan_pc < func_end && !found_return) { if (target_read_memory (scan_pc, buf, 2)) break; scan_pc += 2; insn = extract_unsigned_integer (buf, 2, byte_order_for_code); if ((insn & 0xff80) == 0x4700) /* bx */ found_return = 1; else if (insn == 0x46f7) /* mov pc, lr */ found_return = 1; else if (thumb_instruction_restores_sp (insn)) { if ((insn & 0xff00) == 0xbd00) /* pop */ found_return = 1; } else if (thumb_insn_size (insn) == 4) /* 32-bit Thumb-2 instruction */ { if (target_read_memory (scan_pc, buf, 2)) break; scan_pc += 2; insn2 = extract_unsigned_integer (buf, 2, byte_order_for_code); if (insn == 0xe8bd) /* ldm.w sp!, */ { if (insn2 & 0x8000) /* include PC. */ found_return = 1; } else if (insn == 0xf85d /* ldr.w , [sp], #4 */ && (insn2 & 0x0fff) == 0x0b04) { if ((insn2 & 0xf000) == 0xf000) /* is PC. */ found_return = 1; } else if ((insn & 0xffbf) == 0xecbd /* vldm sp!, */ && (insn2 & 0x0e00) == 0x0a00) ; else break; } else break; } if (!found_return) return 0; /* Since any instruction in the epilogue sequence, with the possible exception of return itself, updates the stack pointer, we need to scan backwards for at most one instruction. Try either a 16-bit or a 32-bit instruction. This is just a heuristic, so we do not worry too much about false positives. */ if (pc - 4 < func_start) return 0; if (target_read_memory (pc - 4, buf, 4)) return 0; insn = extract_unsigned_integer (buf, 2, byte_order_for_code); insn2 = extract_unsigned_integer (buf + 2, 2, byte_order_for_code); if (thumb_instruction_restores_sp (insn2)) found_stack_adjust = 1; else if (insn == 0xe8bd) /* ldm.w sp!, */ found_stack_adjust = 1; else if (insn == 0xf85d /* ldr.w , [sp], #4 */ && (insn2 & 0x0fff) == 0x0b04) found_stack_adjust = 1; else if ((insn & 0xffbf) == 0xecbd /* vldm sp!, */ && (insn2 & 0x0e00) == 0x0a00) found_stack_adjust = 1; return found_stack_adjust; } static int arm_stack_frame_destroyed_p_1 (struct gdbarch *gdbarch, CORE_ADDR pc) { enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch); unsigned int insn; int found_return; CORE_ADDR func_start, func_end; if (!find_pc_partial_function (pc, NULL, &func_start, &func_end)) return 0; /* We are in the epilogue if the previous instruction was a stack adjustment and the next instruction is a possible return (bx, mov pc, or pop). We could have to scan backwards to find the stack adjustment, or forwards to find the return, but this is a decent approximation. First scan forwards. */ found_return = 0; insn = read_memory_unsigned_integer (pc, 4, byte_order_for_code); if (bits (insn, 28, 31) != INST_NV) { if ((insn & 0x0ffffff0) == 0x012fff10) /* BX. */ found_return = 1; else if ((insn & 0x0ffffff0) == 0x01a0f000) /* MOV PC. */ found_return = 1; else if ((insn & 0x0fff0000) == 0x08bd0000 && (insn & 0x0000c000) != 0) /* POP (LDMIA), including PC or LR. */ found_return = 1; } if (!found_return) return 0; /* Scan backwards. This is just a heuristic, so do not worry about false positives from mode changes. */ if (pc < func_start + 4) return 0; insn = read_memory_unsigned_integer (pc - 4, 4, byte_order_for_code); if (arm_instruction_restores_sp (insn)) return 1; return 0; } /* Implement the stack_frame_destroyed_p gdbarch method. */ static int arm_stack_frame_destroyed_p (struct gdbarch *gdbarch, CORE_ADDR pc) { if (arm_pc_is_thumb (gdbarch, pc)) return thumb_stack_frame_destroyed_p (gdbarch, pc); else return arm_stack_frame_destroyed_p_1 (gdbarch, pc); } /* When arguments must be pushed onto the stack, they go on in reverse order. The code below implements a FILO (stack) to do this. */ struct arm_stack_item { int len; struct arm_stack_item *prev; gdb_byte *data; }; static struct arm_stack_item * push_stack_item (struct arm_stack_item *prev, const gdb_byte *contents, int len) { struct arm_stack_item *si; si = XNEW (struct arm_stack_item); si->data = (gdb_byte *) xmalloc (len); si->len = len; si->prev = prev; memcpy (si->data, contents, len); return si; } static struct arm_stack_item * pop_stack_item (struct arm_stack_item *si) { struct arm_stack_item *dead = si; si = si->prev; xfree (dead->data); xfree (dead); return si; } /* Implement the gdbarch type alignment method, overrides the generic alignment algorithm for anything that is arm specific. */ static ULONGEST arm_type_align (gdbarch *gdbarch, struct type *t) { t = check_typedef (t); if (t->code () == TYPE_CODE_ARRAY && t->is_vector ()) { /* Use the natural alignment for vector types (the same for scalar type), but the maximum alignment is 64-bit. */ if (t->length () > 8) return 8; else return t->length (); } /* Allow the common code to calculate the alignment. */ return 0; } /* Possible base types for a candidate for passing and returning in VFP registers. */ enum arm_vfp_cprc_base_type { VFP_CPRC_UNKNOWN, VFP_CPRC_SINGLE, VFP_CPRC_DOUBLE, VFP_CPRC_VEC64, VFP_CPRC_VEC128 }; /* The length of one element of base type B. */ static unsigned arm_vfp_cprc_unit_length (enum arm_vfp_cprc_base_type b) { switch (b) { case VFP_CPRC_SINGLE: return 4; case VFP_CPRC_DOUBLE: return 8; case VFP_CPRC_VEC64: return 8; case VFP_CPRC_VEC128: return 16; default: internal_error (_("Invalid VFP CPRC type: %d."), (int) b); } } /* The character ('s', 'd' or 'q') for the type of VFP register used for passing base type B. */ static int arm_vfp_cprc_reg_char (enum arm_vfp_cprc_base_type b) { switch (b) { case VFP_CPRC_SINGLE: return 's'; case VFP_CPRC_DOUBLE: return 'd'; case VFP_CPRC_VEC64: return 'd'; case VFP_CPRC_VEC128: return 'q'; default: internal_error (_("Invalid VFP CPRC type: %d."), (int) b); } } /* Determine whether T may be part of a candidate for passing and returning in VFP registers, ignoring the limit on the total number of components. If *BASE_TYPE is VFP_CPRC_UNKNOWN, set it to the classification of the first valid component found; if it is not VFP_CPRC_UNKNOWN, all components must have the same classification as *BASE_TYPE. If it is found that T contains a type not permitted for passing and returning in VFP registers, a type differently classified from *BASE_TYPE, or two types differently classified from each other, return -1, otherwise return the total number of base-type elements found (possibly 0 in an empty structure or array). Vector types are not currently supported, matching the generic AAPCS support. */ static int arm_vfp_cprc_sub_candidate (struct type *t, enum arm_vfp_cprc_base_type *base_type) { t = check_typedef (t); switch (t->code ()) { case TYPE_CODE_FLT: switch (t->length ()) { case 4: if (*base_type == VFP_CPRC_UNKNOWN) *base_type = VFP_CPRC_SINGLE; else if (*base_type != VFP_CPRC_SINGLE) return -1; return 1; case 8: if (*base_type == VFP_CPRC_UNKNOWN) *base_type = VFP_CPRC_DOUBLE; else if (*base_type != VFP_CPRC_DOUBLE) return -1; return 1; default: return -1; } break; case TYPE_CODE_COMPLEX: /* Arguments of complex T where T is one of the types float or double get treated as if they are implemented as: struct complexT { T real; T imag; }; */ switch (t->length ()) { case 8: if (*base_type == VFP_CPRC_UNKNOWN) *base_type = VFP_CPRC_SINGLE; else if (*base_type != VFP_CPRC_SINGLE) return -1; return 2; case 16: if (*base_type == VFP_CPRC_UNKNOWN) *base_type = VFP_CPRC_DOUBLE; else if (*base_type != VFP_CPRC_DOUBLE) return -1; return 2; default: return -1; } break; case TYPE_CODE_ARRAY: { if (t->is_vector ()) { /* A 64-bit or 128-bit containerized vector type are VFP CPRCs. */ switch (t->length ()) { case 8: if (*base_type == VFP_CPRC_UNKNOWN) *base_type = VFP_CPRC_VEC64; return 1; case 16: if (*base_type == VFP_CPRC_UNKNOWN) *base_type = VFP_CPRC_VEC128; return 1; default: return -1; } } else { int count; unsigned unitlen; count = arm_vfp_cprc_sub_candidate (t->target_type (), base_type); if (count == -1) return -1; if (t->length () == 0) { gdb_assert (count == 0); return 0; } else if (count == 0) return -1; unitlen = arm_vfp_cprc_unit_length (*base_type); gdb_assert ((t->length () % unitlen) == 0); return t->length () / unitlen; } } break; case TYPE_CODE_STRUCT: { int count = 0; unsigned unitlen; int i; for (i = 0; i < t->num_fields (); i++) { int sub_count = 0; if (!t->field (i).is_static ()) sub_count = arm_vfp_cprc_sub_candidate (t->field (i).type (), base_type); if (sub_count == -1) return -1; count += sub_count; } if (t->length () == 0) { gdb_assert (count == 0); return 0; } else if (count == 0) return -1; unitlen = arm_vfp_cprc_unit_length (*base_type); if (t->length () != unitlen * count) return -1; return count; } case TYPE_CODE_UNION: { int count = 0; unsigned unitlen; int i; for (i = 0; i < t->num_fields (); i++) { int sub_count = arm_vfp_cprc_sub_candidate (t->field (i).type (), base_type); if (sub_count == -1) return -1; count = (count > sub_count ? count : sub_count); } if (t->length () == 0) { gdb_assert (count == 0); return 0; } else if (count == 0) return -1; unitlen = arm_vfp_cprc_unit_length (*base_type); if (t->length () != unitlen * count) return -1; return count; } default: break; } return -1; } /* Determine whether T is a VFP co-processor register candidate (CPRC) if passed to or returned from a non-variadic function with the VFP ABI in effect. Return 1 if it is, 0 otherwise. If it is, set *BASE_TYPE to the base type for T and *COUNT to the number of elements of that base type before returning. */ static int arm_vfp_call_candidate (struct type *t, enum arm_vfp_cprc_base_type *base_type, int *count) { enum arm_vfp_cprc_base_type b = VFP_CPRC_UNKNOWN; int c = arm_vfp_cprc_sub_candidate (t, &b); if (c <= 0 || c > 4) return 0; *base_type = b; *count = c; return 1; } /* Return 1 if the VFP ABI should be used for passing arguments to and returning values from a function of type FUNC_TYPE, 0 otherwise. */ static int arm_vfp_abi_for_function (struct gdbarch *gdbarch, struct type *func_type) { arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); /* Variadic functions always use the base ABI. Assume that functions without debug info are not variadic. */ if (func_type && check_typedef (func_type)->has_varargs ()) return 0; /* The VFP ABI is only supported as a variant of AAPCS. */ if (tdep->arm_abi != ARM_ABI_AAPCS) return 0; return tdep->fp_model == ARM_FLOAT_VFP; } /* We currently only support passing parameters in integer registers, which conforms with GCC's default model, and VFP argument passing following the VFP variant of AAPCS. Several other variants exist and we should probably support some of them based on the selected ABI. */ static CORE_ADDR arm_push_dummy_call (struct gdbarch *gdbarch, struct value *function, struct regcache *regcache, CORE_ADDR bp_addr, int nargs, struct value **args, CORE_ADDR sp, function_call_return_method return_method, CORE_ADDR struct_addr) { enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); int argnum; int argreg; int nstack; struct arm_stack_item *si = NULL; int use_vfp_abi; struct type *ftype; unsigned vfp_regs_free = (1 << 16) - 1; arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); /* Determine the type of this function and whether the VFP ABI applies. */ ftype = check_typedef (function->type ()); if (ftype->code () == TYPE_CODE_PTR) ftype = check_typedef (ftype->target_type ()); use_vfp_abi = arm_vfp_abi_for_function (gdbarch, ftype); /* Set the return address. For the ARM, the return breakpoint is always at BP_ADDR. */ if (arm_pc_is_thumb (gdbarch, bp_addr)) bp_addr |= 1; regcache_cooked_write_unsigned (regcache, ARM_LR_REGNUM, bp_addr); /* Walk through the list of args and determine how large a temporary stack is required. Need to take care here as structs may be passed on the stack, and we have to push them. */ nstack = 0; argreg = ARM_A1_REGNUM; nstack = 0; /* The struct_return pointer occupies the first parameter passing register. */ if (return_method == return_method_struct) { arm_debug_printf ("struct return in %s = %s", gdbarch_register_name (gdbarch, argreg), paddress (gdbarch, struct_addr)); regcache_cooked_write_unsigned (regcache, argreg, struct_addr); argreg++; } for (argnum = 0; argnum < nargs; argnum++) { int len; struct type *arg_type; struct type *target_type; enum type_code typecode; const bfd_byte *val; int align; enum arm_vfp_cprc_base_type vfp_base_type; int vfp_base_count; int may_use_core_reg = 1; arg_type = check_typedef (args[argnum]->type ()); len = arg_type->length (); target_type = arg_type->target_type (); typecode = arg_type->code (); val = args[argnum]->contents ().data (); align = type_align (arg_type); /* Round alignment up to a whole number of words. */ align = (align + ARM_INT_REGISTER_SIZE - 1) & ~(ARM_INT_REGISTER_SIZE - 1); /* Different ABIs have different maximum alignments. */ if (tdep->arm_abi == ARM_ABI_APCS) { /* The APCS ABI only requires word alignment. */ align = ARM_INT_REGISTER_SIZE; } else { /* The AAPCS requires at most doubleword alignment. */ if (align > ARM_INT_REGISTER_SIZE * 2) align = ARM_INT_REGISTER_SIZE * 2; } if (use_vfp_abi && arm_vfp_call_candidate (arg_type, &vfp_base_type, &vfp_base_count)) { int regno; int unit_length; int shift; unsigned mask; /* Because this is a CPRC it cannot go in a core register or cause a core register to be skipped for alignment. Either it goes in VFP registers and the rest of this loop iteration is skipped for this argument, or it goes on the stack (and the stack alignment code is correct for this case). */ may_use_core_reg = 0; unit_length = arm_vfp_cprc_unit_length (vfp_base_type); shift = unit_length / 4; mask = (1 << (shift * vfp_base_count)) - 1; for (regno = 0; regno < 16; regno += shift) if (((vfp_regs_free >> regno) & mask) == mask) break; if (regno < 16) { int reg_char; int reg_scaled; int i; vfp_regs_free &= ~(mask << regno); reg_scaled = regno / shift; reg_char = arm_vfp_cprc_reg_char (vfp_base_type); for (i = 0; i < vfp_base_count; i++) { char name_buf[4]; int regnum; if (reg_char == 'q') arm_neon_quad_write (gdbarch, regcache, reg_scaled + i, val + i * unit_length); else { xsnprintf (name_buf, sizeof (name_buf), "%c%d", reg_char, reg_scaled + i); regnum = user_reg_map_name_to_regnum (gdbarch, name_buf, strlen (name_buf)); regcache->cooked_write (regnum, val + i * unit_length); } } continue; } else { /* This CPRC could not go in VFP registers, so all VFP registers are now marked as used. */ vfp_regs_free = 0; } } /* Push stack padding for doubleword alignment. */ if (nstack & (align - 1)) { si = push_stack_item (si, val, ARM_INT_REGISTER_SIZE); nstack += ARM_INT_REGISTER_SIZE; } /* Doubleword aligned quantities must go in even register pairs. */ if (may_use_core_reg && argreg <= ARM_LAST_ARG_REGNUM && align > ARM_INT_REGISTER_SIZE && argreg & 1) argreg++; /* If the argument is a pointer to a function, and it is a Thumb function, create a LOCAL copy of the value and set the THUMB bit in it. */ if (TYPE_CODE_PTR == typecode && target_type != NULL && TYPE_CODE_FUNC == check_typedef (target_type)->code ()) { CORE_ADDR regval = extract_unsigned_integer (val, len, byte_order); if (arm_pc_is_thumb (gdbarch, regval)) { bfd_byte *copy = (bfd_byte *) alloca (len); store_unsigned_integer (copy, len, byte_order, MAKE_THUMB_ADDR (regval)); val = copy; } } /* Copy the argument to general registers or the stack in register-sized pieces. Large arguments are split between registers and stack. */ while (len > 0) { int partial_len = len < ARM_INT_REGISTER_SIZE ? len : ARM_INT_REGISTER_SIZE; CORE_ADDR regval = extract_unsigned_integer (val, partial_len, byte_order); if (may_use_core_reg && argreg <= ARM_LAST_ARG_REGNUM) { /* The argument is being passed in a general purpose register. */ if (byte_order == BFD_ENDIAN_BIG) regval <<= (ARM_INT_REGISTER_SIZE - partial_len) * 8; arm_debug_printf ("arg %d in %s = 0x%s", argnum, gdbarch_register_name (gdbarch, argreg), phex (regval, ARM_INT_REGISTER_SIZE)); regcache_cooked_write_unsigned (regcache, argreg, regval); argreg++; } else { gdb_byte buf[ARM_INT_REGISTER_SIZE]; memset (buf, 0, sizeof (buf)); store_unsigned_integer (buf, partial_len, byte_order, regval); /* Push the arguments onto the stack. */ arm_debug_printf ("arg %d @ sp + %d", argnum, nstack); si = push_stack_item (si, buf, ARM_INT_REGISTER_SIZE); nstack += ARM_INT_REGISTER_SIZE; } len -= partial_len; val += partial_len; } } /* If we have an odd number of words to push, then decrement the stack by one word now, so first stack argument will be dword aligned. */ if (nstack & 4) sp -= 4; while (si) { sp -= si->len; write_memory (sp, si->data, si->len); si = pop_stack_item (si); } /* Finally, update teh SP register. */ regcache_cooked_write_unsigned (regcache, ARM_SP_REGNUM, sp); return sp; } /* Always align the frame to an 8-byte boundary. This is required on some platforms and harmless on the rest. */ static CORE_ADDR arm_frame_align (struct gdbarch *gdbarch, CORE_ADDR sp) { /* Align the stack to eight bytes. */ return sp & ~ (CORE_ADDR) 7; } static void print_fpu_flags (struct ui_file *file, int flags) { if (flags & (1 << 0)) gdb_puts ("IVO ", file); if (flags & (1 << 1)) gdb_puts ("DVZ ", file); if (flags & (1 << 2)) gdb_puts ("OFL ", file); if (flags & (1 << 3)) gdb_puts ("UFL ", file); if (flags & (1 << 4)) gdb_puts ("INX ", file); gdb_putc ('\n', file); } /* Print interesting information about the floating point processor (if present) or emulator. */ static void arm_print_float_info (struct gdbarch *gdbarch, struct ui_file *file, frame_info_ptr frame, const char *args) { unsigned long status = get_frame_register_unsigned (frame, ARM_FPS_REGNUM); int type; type = (status >> 24) & 127; if (status & (1 << 31)) gdb_printf (file, _("Hardware FPU type %d\n"), type); else gdb_printf (file, _("Software FPU type %d\n"), type); /* i18n: [floating point unit] mask */ gdb_puts (_("mask: "), file); print_fpu_flags (file, status >> 16); /* i18n: [floating point unit] flags */ gdb_puts (_("flags: "), file); print_fpu_flags (file, status); } /* Construct the ARM extended floating point type. */ static struct type * arm_ext_type (struct gdbarch *gdbarch) { arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); if (!tdep->arm_ext_type) { type_allocator alloc (gdbarch); tdep->arm_ext_type = init_float_type (alloc, -1, "builtin_type_arm_ext", floatformats_arm_ext); } return tdep->arm_ext_type; } static struct type * arm_neon_double_type (struct gdbarch *gdbarch) { arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); if (tdep->neon_double_type == NULL) { struct type *t, *elem; t = arch_composite_type (gdbarch, "__gdb_builtin_type_neon_d", TYPE_CODE_UNION); elem = builtin_type (gdbarch)->builtin_uint8; append_composite_type_field (t, "u8", init_vector_type (elem, 8)); elem = builtin_type (gdbarch)->builtin_uint16; append_composite_type_field (t, "u16", init_vector_type (elem, 4)); elem = builtin_type (gdbarch)->builtin_uint32; append_composite_type_field (t, "u32", init_vector_type (elem, 2)); elem = builtin_type (gdbarch)->builtin_uint64; append_composite_type_field (t, "u64", elem); elem = builtin_type (gdbarch)->builtin_float; append_composite_type_field (t, "f32", init_vector_type (elem, 2)); elem = builtin_type (gdbarch)->builtin_double; append_composite_type_field (t, "f64", elem); t->set_is_vector (true); t->set_name ("neon_d"); tdep->neon_double_type = t; } return tdep->neon_double_type; } /* FIXME: The vector types are not correctly ordered on big-endian targets. Just as s0 is the low bits of d0, d0[0] is also the low bits of d0 - regardless of what unit size is being held in d0. So the offset of the first uint8 in d0 is 7, but the offset of the first float is 4. This code works as-is for little-endian targets. */ static struct type * arm_neon_quad_type (struct gdbarch *gdbarch) { arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); if (tdep->neon_quad_type == NULL) { struct type *t, *elem; t = arch_composite_type (gdbarch, "__gdb_builtin_type_neon_q", TYPE_CODE_UNION); elem = builtin_type (gdbarch)->builtin_uint8; append_composite_type_field (t, "u8", init_vector_type (elem, 16)); elem = builtin_type (gdbarch)->builtin_uint16; append_composite_type_field (t, "u16", init_vector_type (elem, 8)); elem = builtin_type (gdbarch)->builtin_uint32; append_composite_type_field (t, "u32", init_vector_type (elem, 4)); elem = builtin_type (gdbarch)->builtin_uint64; append_composite_type_field (t, "u64", init_vector_type (elem, 2)); elem = builtin_type (gdbarch)->builtin_float; append_composite_type_field (t, "f32", init_vector_type (elem, 4)); elem = builtin_type (gdbarch)->builtin_double; append_composite_type_field (t, "f64", init_vector_type (elem, 2)); t->set_is_vector (true); t->set_name ("neon_q"); tdep->neon_quad_type = t; } return tdep->neon_quad_type; } /* Return true if REGNUM is a Q pseudo register. Return false otherwise. REGNUM is the raw register number and not a pseudo-relative register number. */ static bool is_q_pseudo (struct gdbarch *gdbarch, int regnum) { arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); /* Q pseudo registers are available for both NEON (Q0~Q15) and MVE (Q0~Q7) features. */ if (tdep->have_q_pseudos && regnum >= tdep->q_pseudo_base && regnum < (tdep->q_pseudo_base + tdep->q_pseudo_count)) return true; return false; } /* Return true if REGNUM is a VFP S pseudo register. Return false otherwise. REGNUM is the raw register number and not a pseudo-relative register number. */ static bool is_s_pseudo (struct gdbarch *gdbarch, int regnum) { arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); if (tdep->have_s_pseudos && regnum >= tdep->s_pseudo_base && regnum < (tdep->s_pseudo_base + tdep->s_pseudo_count)) return true; return false; } /* Return true if REGNUM is a MVE pseudo register (P0). Return false otherwise. REGNUM is the raw register number and not a pseudo-relative register number. */ static bool is_mve_pseudo (struct gdbarch *gdbarch, int regnum) { arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); if (tdep->have_mve && regnum >= tdep->mve_pseudo_base && regnum < tdep->mve_pseudo_base + tdep->mve_pseudo_count) return true; return false; } /* Return true if REGNUM is a PACBTI pseudo register (ra_auth_code). Return false otherwise. REGNUM is the raw register number and not a pseudo-relative register number. */ static bool is_pacbti_pseudo (struct gdbarch *gdbarch, int regnum) { arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); if (tdep->have_pacbti && regnum >= tdep->pacbti_pseudo_base && regnum < tdep->pacbti_pseudo_base + tdep->pacbti_pseudo_count) return true; return false; } /* Return the GDB type object for the "standard" data type of data in register N. */ static struct type * arm_register_type (struct gdbarch *gdbarch, int regnum) { arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); if (is_s_pseudo (gdbarch, regnum)) return builtin_type (gdbarch)->builtin_float; if (is_q_pseudo (gdbarch, regnum)) return arm_neon_quad_type (gdbarch); if (is_mve_pseudo (gdbarch, regnum)) return builtin_type (gdbarch)->builtin_int16; if (is_pacbti_pseudo (gdbarch, regnum)) return builtin_type (gdbarch)->builtin_uint32; /* If the target description has register information, we are only in this function so that we can override the types of double-precision registers for NEON. */ if (tdesc_has_registers (gdbarch_target_desc (gdbarch))) { struct type *t = tdesc_register_type (gdbarch, regnum); if (regnum >= ARM_D0_REGNUM && regnum < ARM_D0_REGNUM + 32 && t->code () == TYPE_CODE_FLT && tdep->have_neon) return arm_neon_double_type (gdbarch); else return t; } if (regnum >= ARM_F0_REGNUM && regnum < ARM_F0_REGNUM + NUM_FREGS) { if (!tdep->have_fpa_registers) return builtin_type (gdbarch)->builtin_void; return arm_ext_type (gdbarch); } else if (regnum == ARM_SP_REGNUM) return builtin_type (gdbarch)->builtin_data_ptr; else if (regnum == ARM_PC_REGNUM) return builtin_type (gdbarch)->builtin_func_ptr; else if (regnum >= ARRAY_SIZE (arm_register_names)) /* These registers are only supported on targets which supply an XML description. */ return builtin_type (gdbarch)->builtin_int0; else return builtin_type (gdbarch)->builtin_uint32; } /* Map a DWARF register REGNUM onto the appropriate GDB register number. */ static int arm_dwarf_reg_to_regnum (struct gdbarch *gdbarch, int reg) { /* Core integer regs. */ if (reg >= 0 && reg <= 15) return reg; /* Legacy FPA encoding. These were once used in a way which overlapped with VFP register numbering, so their use is discouraged, but GDB doesn't support the ARM toolchain which used them for VFP. */ if (reg >= 16 && reg <= 23) return ARM_F0_REGNUM + reg - 16; /* New assignments for the FPA registers. */ if (reg >= 96 && reg <= 103) return ARM_F0_REGNUM + reg - 96; /* WMMX register assignments. */ if (reg >= 104 && reg <= 111) return ARM_WCGR0_REGNUM + reg - 104; if (reg >= 112 && reg <= 127) return ARM_WR0_REGNUM + reg - 112; /* PACBTI register containing the Pointer Authentication Code. */ if (reg == ARM_DWARF_RA_AUTH_CODE) { arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); if (tdep->have_pacbti) return tdep->pacbti_pseudo_base; return -1; } if (reg >= 192 && reg <= 199) return ARM_WC0_REGNUM + reg - 192; /* VFP v2 registers. A double precision value is actually in d1 rather than s2, but the ABI only defines numbering for the single precision registers. This will "just work" in GDB for little endian targets (we'll read eight bytes, starting in s0 and then progressing to s1), but will be reversed on big endian targets with VFP. This won't be a problem for the new Neon quad registers; you're supposed to use DW_OP_piece for those. */ if (reg >= 64 && reg <= 95) { char name_buf[4]; xsnprintf (name_buf, sizeof (name_buf), "s%d", reg - 64); return user_reg_map_name_to_regnum (gdbarch, name_buf, strlen (name_buf)); } /* VFP v3 / Neon registers. This range is also used for VFP v2 registers, except that it now describes d0 instead of s0. */ if (reg >= 256 && reg <= 287) { char name_buf[4]; xsnprintf (name_buf, sizeof (name_buf), "d%d", reg - 256); return user_reg_map_name_to_regnum (gdbarch, name_buf, strlen (name_buf)); } return -1; } /* Map GDB internal REGNUM onto the Arm simulator register numbers. */ static int arm_register_sim_regno (struct gdbarch *gdbarch, int regnum) { int reg = regnum; gdb_assert (reg >= 0 && reg < gdbarch_num_regs (gdbarch)); if (regnum >= ARM_WR0_REGNUM && regnum <= ARM_WR15_REGNUM) return regnum - ARM_WR0_REGNUM + SIM_ARM_IWMMXT_COP0R0_REGNUM; if (regnum >= ARM_WC0_REGNUM && regnum <= ARM_WC7_REGNUM) return regnum - ARM_WC0_REGNUM + SIM_ARM_IWMMXT_COP1R0_REGNUM; if (regnum >= ARM_WCGR0_REGNUM && regnum <= ARM_WCGR7_REGNUM) return regnum - ARM_WCGR0_REGNUM + SIM_ARM_IWMMXT_COP1R8_REGNUM; if (reg < NUM_GREGS) return SIM_ARM_R0_REGNUM + reg; reg -= NUM_GREGS; if (reg < NUM_FREGS) return SIM_ARM_FP0_REGNUM + reg; reg -= NUM_FREGS; if (reg < NUM_SREGS) return SIM_ARM_FPS_REGNUM + reg; reg -= NUM_SREGS; internal_error (_("Bad REGNUM %d"), regnum); } static const unsigned char op_lit0 = DW_OP_lit0; static void arm_dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum, struct dwarf2_frame_state_reg *reg, frame_info_ptr this_frame) { arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); if (is_pacbti_pseudo (gdbarch, regnum)) { /* Initialize RA_AUTH_CODE to zero. */ reg->how = DWARF2_FRAME_REG_SAVED_VAL_EXP; reg->loc.exp.start = &op_lit0; reg->loc.exp.len = 1; return; } if (regnum == ARM_PC_REGNUM || regnum == ARM_PS_REGNUM) { reg->how = DWARF2_FRAME_REG_FN; reg->loc.fn = arm_dwarf2_prev_register; } else if (regnum == ARM_SP_REGNUM) reg->how = DWARF2_FRAME_REG_CFA; else if (arm_is_alternative_sp_register (tdep, regnum)) { /* Handle the alternative SP registers on Cortex-M. */ reg->how = DWARF2_FRAME_REG_FN; reg->loc.fn = arm_dwarf2_prev_register; } } /* Given BUF, which is OLD_LEN bytes ending at ENDADDR, expand the buffer to be NEW_LEN bytes ending at ENDADDR. Return NULL if an error occurs. BUF is freed. */ static gdb_byte * extend_buffer_earlier (gdb_byte *buf, CORE_ADDR endaddr, int old_len, int new_len) { gdb_byte *new_buf; int bytes_to_read = new_len - old_len; new_buf = (gdb_byte *) xmalloc (new_len); memcpy (new_buf + bytes_to_read, buf, old_len); xfree (buf); if (target_read_code (endaddr - new_len, new_buf, bytes_to_read) != 0) { xfree (new_buf); return NULL; } return new_buf; } /* An IT block is at most the 2-byte IT instruction followed by four 4-byte instructions. The furthest back we must search to find an IT block that affects the current instruction is thus 2 + 3 * 4 == 14 bytes. */ #define MAX_IT_BLOCK_PREFIX 14 /* Use a quick scan if there are more than this many bytes of code. */ #define IT_SCAN_THRESHOLD 32 /* Adjust a breakpoint's address to move breakpoints out of IT blocks. A breakpoint in an IT block may not be hit, depending on the condition flags. */ static CORE_ADDR arm_adjust_breakpoint_address (struct gdbarch *gdbarch, CORE_ADDR bpaddr) { gdb_byte *buf; char map_type; CORE_ADDR boundary, func_start; int buf_len; enum bfd_endian order = gdbarch_byte_order_for_code (gdbarch); int i, any, last_it, last_it_count; arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); /* If we are using BKPT breakpoints, none of this is necessary. */ if (tdep->thumb2_breakpoint == NULL) return bpaddr; /* ARM mode does not have this problem. */ if (!arm_pc_is_thumb (gdbarch, bpaddr)) return bpaddr; /* We are setting a breakpoint in Thumb code that could potentially contain an IT block. The first step is to find how much Thumb code there is; we do not need to read outside of known Thumb sequences. */ map_type = arm_find_mapping_symbol (bpaddr, &boundary); if (map_type == 0) /* Thumb-2 code must have mapping symbols to have a chance. */ return bpaddr; bpaddr = gdbarch_addr_bits_remove (gdbarch, bpaddr); if (find_pc_partial_function (bpaddr, NULL, &func_start, NULL) && func_start > boundary) boundary = func_start; /* Search for a candidate IT instruction. We have to do some fancy footwork to distinguish a real IT instruction from the second half of a 32-bit instruction, but there is no need for that if there's no candidate. */ buf_len = std::min (bpaddr - boundary, (CORE_ADDR) MAX_IT_BLOCK_PREFIX); if (buf_len == 0) /* No room for an IT instruction. */ return bpaddr; buf = (gdb_byte *) xmalloc (buf_len); if (target_read_code (bpaddr - buf_len, buf, buf_len) != 0) return bpaddr; any = 0; for (i = 0; i < buf_len; i += 2) { unsigned short inst1 = extract_unsigned_integer (&buf[i], 2, order); if ((inst1 & 0xff00) == 0xbf00 && (inst1 & 0x000f) != 0) { any = 1; break; } } if (any == 0) { xfree (buf); return bpaddr; } /* OK, the code bytes before this instruction contain at least one halfword which resembles an IT instruction. We know that it's Thumb code, but there are still two possibilities. Either the halfword really is an IT instruction, or it is the second half of a 32-bit Thumb instruction. The only way we can tell is to scan forwards from a known instruction boundary. */ if (bpaddr - boundary > IT_SCAN_THRESHOLD) { int definite; /* There's a lot of code before this instruction. Start with an optimistic search; it's easy to recognize halfwords that can not be the start of a 32-bit instruction, and use that to lock on to the instruction boundaries. */ buf = extend_buffer_earlier (buf, bpaddr, buf_len, IT_SCAN_THRESHOLD); if (buf == NULL) return bpaddr; buf_len = IT_SCAN_THRESHOLD; definite = 0; for (i = 0; i < buf_len - sizeof (buf) && ! definite; i += 2) { unsigned short inst1 = extract_unsigned_integer (&buf[i], 2, order); if (thumb_insn_size (inst1) == 2) { definite = 1; break; } } /* At this point, if DEFINITE, BUF[I] is the first place we are sure that we know the instruction boundaries, and it is far enough from BPADDR that we could not miss an IT instruction affecting BPADDR. If ! DEFINITE, give up - start from a known boundary. */ if (! definite) { buf = extend_buffer_earlier (buf, bpaddr, buf_len, bpaddr - boundary); if (buf == NULL) return bpaddr; buf_len = bpaddr - boundary; i = 0; } } else { buf = extend_buffer_earlier (buf, bpaddr, buf_len, bpaddr - boundary); if (buf == NULL) return bpaddr; buf_len = bpaddr - boundary; i = 0; } /* Scan forwards. Find the last IT instruction before BPADDR. */ last_it = -1; last_it_count = 0; while (i < buf_len) { unsigned short inst1 = extract_unsigned_integer (&buf[i], 2, order); last_it_count--; if ((inst1 & 0xff00) == 0xbf00 && (inst1 & 0x000f) != 0) { last_it = i; if (inst1 & 0x0001) last_it_count = 4; else if (inst1 & 0x0002) last_it_count = 3; else if (inst1 & 0x0004) last_it_count = 2; else last_it_count = 1; } i += thumb_insn_size (inst1); } xfree (buf); if (last_it == -1) /* There wasn't really an IT instruction after all. */ return bpaddr; if (last_it_count < 1) /* It was too far away. */ return bpaddr; /* This really is a trouble spot. Move the breakpoint to the IT instruction. */ return bpaddr - buf_len + last_it; } /* ARM displaced stepping support. Generally ARM displaced stepping works as follows: 1. When an instruction is to be single-stepped, it is first decoded by arm_process_displaced_insn. Depending on the type of instruction, it is then copied to a scratch location, possibly in a modified form. The copy_* set of functions performs such modification, as necessary. A breakpoint is placed after the modified instruction in the scratch space to return control to GDB. Note in particular that instructions which modify the PC will no longer do so after modification. 2. The instruction is single-stepped, by setting the PC to the scratch location address, and resuming. Control returns to GDB when the breakpoint is hit. 3. A cleanup function (cleanup_*) is called corresponding to the copy_* function used for the current instruction. This function's job is to put the CPU/memory state back to what it would have been if the instruction had been executed unmodified in its original location. */ /* NOP instruction (mov r0, r0). */ #define ARM_NOP 0xe1a00000 #define THUMB_NOP 0x4600 /* Helper for register reads for displaced stepping. In particular, this returns the PC as it would be seen by the instruction at its original location. */ ULONGEST displaced_read_reg (regcache *regs, arm_displaced_step_copy_insn_closure *dsc, int regno) { ULONGEST ret; CORE_ADDR from = dsc->insn_addr; if (regno == ARM_PC_REGNUM) { /* Compute pipeline offset: - When executing an ARM instruction, PC reads as the address of the current instruction plus 8. - When executing a Thumb instruction, PC reads as the address of the current instruction plus 4. */ if (!dsc->is_thumb) from += 8; else from += 4; displaced_debug_printf ("read pc value %.8lx", (unsigned long) from); return (ULONGEST) from; } else { regcache_cooked_read_unsigned (regs, regno, &ret); displaced_debug_printf ("read r%d value %.8lx", regno, (unsigned long) ret); return ret; } } static int displaced_in_arm_mode (struct regcache *regs) { ULONGEST ps; ULONGEST t_bit = arm_psr_thumb_bit (regs->arch ()); regcache_cooked_read_unsigned (regs, ARM_PS_REGNUM, &ps); return (ps & t_bit) == 0; } /* Write to the PC as from a branch instruction. */ static void branch_write_pc (regcache *regs, arm_displaced_step_copy_insn_closure *dsc, ULONGEST val) { if (!dsc->is_thumb) /* Note: If bits 0/1 are set, this branch would be unpredictable for architecture versions < 6. */ regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, val & ~(ULONGEST) 0x3); else regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, val & ~(ULONGEST) 0x1); } /* Write to the PC as from a branch-exchange instruction. */ static void bx_write_pc (struct regcache *regs, ULONGEST val) { ULONGEST ps; ULONGEST t_bit = arm_psr_thumb_bit (regs->arch ()); regcache_cooked_read_unsigned (regs, ARM_PS_REGNUM, &ps); if ((val & 1) == 1) { regcache_cooked_write_unsigned (regs, ARM_PS_REGNUM, ps | t_bit); regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, val & 0xfffffffe); } else if ((val & 2) == 0) { regcache_cooked_write_unsigned (regs, ARM_PS_REGNUM, ps & ~t_bit); regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, val); } else { /* Unpredictable behaviour. Try to do something sensible (switch to ARM mode, align dest to 4 bytes). */ warning (_("Single-stepping BX to non-word-aligned ARM instruction.")); regcache_cooked_write_unsigned (regs, ARM_PS_REGNUM, ps & ~t_bit); regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, val & 0xfffffffc); } } /* Write to the PC as if from a load instruction. */ static void load_write_pc (regcache *regs, arm_displaced_step_copy_insn_closure *dsc, ULONGEST val) { if (DISPLACED_STEPPING_ARCH_VERSION >= 5) bx_write_pc (regs, val); else branch_write_pc (regs, dsc, val); } /* Write to the PC as if from an ALU instruction. */ static void alu_write_pc (regcache *regs, arm_displaced_step_copy_insn_closure *dsc, ULONGEST val) { if (DISPLACED_STEPPING_ARCH_VERSION >= 7 && !dsc->is_thumb) bx_write_pc (regs, val); else branch_write_pc (regs, dsc, val); } /* Helper for writing to registers for displaced stepping. Writing to the PC has a varying effects depending on the instruction which does the write: this is controlled by the WRITE_PC argument. */ void displaced_write_reg (regcache *regs, arm_displaced_step_copy_insn_closure *dsc, int regno, ULONGEST val, enum pc_write_style write_pc) { if (regno == ARM_PC_REGNUM) { displaced_debug_printf ("writing pc %.8lx", (unsigned long) val); switch (write_pc) { case BRANCH_WRITE_PC: branch_write_pc (regs, dsc, val); break; case BX_WRITE_PC: bx_write_pc (regs, val); break; case LOAD_WRITE_PC: load_write_pc (regs, dsc, val); break; case ALU_WRITE_PC: alu_write_pc (regs, dsc, val); break; case CANNOT_WRITE_PC: warning (_("Instruction wrote to PC in an unexpected way when " "single-stepping")); break; default: internal_error (_("Invalid argument to displaced_write_reg")); } dsc->wrote_to_pc = 1; } else { displaced_debug_printf ("writing r%d value %.8lx", regno, (unsigned long) val); regcache_cooked_write_unsigned (regs, regno, val); } } /* This function is used to concisely determine if an instruction INSN references PC. Register fields of interest in INSN should have the corresponding fields of BITMASK set to 0b1111. The function returns return 1 if any of these fields in INSN reference the PC (also 0b1111, r15), else it returns 0. */ static int insn_references_pc (uint32_t insn, uint32_t bitmask) { uint32_t lowbit = 1; while (bitmask != 0) { uint32_t mask; for (; lowbit && (bitmask & lowbit) == 0; lowbit <<= 1) ; if (!lowbit) break; mask = lowbit * 0xf; if ((insn & mask) == mask) return 1; bitmask &= ~mask; } return 0; } /* The simplest copy function. Many instructions have the same effect no matter what address they are executed at: in those cases, use this. */ static int arm_copy_unmodified (struct gdbarch *gdbarch, uint32_t insn, const char *iname, arm_displaced_step_copy_insn_closure *dsc) { displaced_debug_printf ("copying insn %.8lx, opcode/class '%s' unmodified", (unsigned long) insn, iname); dsc->modinsn[0] = insn; return 0; } static int thumb_copy_unmodified_32bit (struct gdbarch *gdbarch, uint16_t insn1, uint16_t insn2, const char *iname, arm_displaced_step_copy_insn_closure *dsc) { displaced_debug_printf ("copying insn %.4x %.4x, opcode/class '%s' " "unmodified", insn1, insn2, iname); dsc->modinsn[0] = insn1; dsc->modinsn[1] = insn2; dsc->numinsns = 2; return 0; } /* Copy 16-bit Thumb(Thumb and 16-bit Thumb-2) instruction without any modification. */ static int thumb_copy_unmodified_16bit (struct gdbarch *gdbarch, uint16_t insn, const char *iname, arm_displaced_step_copy_insn_closure *dsc) { displaced_debug_printf ("copying insn %.4x, opcode/class '%s' unmodified", insn, iname); dsc->modinsn[0] = insn; return 0; } /* Preload instructions with immediate offset. */ static void cleanup_preload (struct gdbarch *gdbarch, regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { displaced_write_reg (regs, dsc, 0, dsc->tmp[0], CANNOT_WRITE_PC); if (!dsc->u.preload.immed) displaced_write_reg (regs, dsc, 1, dsc->tmp[1], CANNOT_WRITE_PC); } static void install_preload (struct gdbarch *gdbarch, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc, unsigned int rn) { ULONGEST rn_val; /* Preload instructions: {pli/pld} [rn, #+/-imm] -> {pli/pld} [r0, #+/-imm]. */ dsc->tmp[0] = displaced_read_reg (regs, dsc, 0); rn_val = displaced_read_reg (regs, dsc, rn); displaced_write_reg (regs, dsc, 0, rn_val, CANNOT_WRITE_PC); dsc->u.preload.immed = 1; dsc->cleanup = &cleanup_preload; } static int arm_copy_preload (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { unsigned int rn = bits (insn, 16, 19); if (!insn_references_pc (insn, 0x000f0000ul)) return arm_copy_unmodified (gdbarch, insn, "preload", dsc); displaced_debug_printf ("copying preload insn %.8lx", (unsigned long) insn); dsc->modinsn[0] = insn & 0xfff0ffff; install_preload (gdbarch, regs, dsc, rn); return 0; } static int thumb2_copy_preload (struct gdbarch *gdbarch, uint16_t insn1, uint16_t insn2, regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { unsigned int rn = bits (insn1, 0, 3); unsigned int u_bit = bit (insn1, 7); int imm12 = bits (insn2, 0, 11); ULONGEST pc_val; if (rn != ARM_PC_REGNUM) return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "preload", dsc); /* PC is only allowed to use in PLI (immediate,literal) Encoding T3, and PLD (literal) Encoding T1. */ displaced_debug_printf ("copying pld/pli pc (0x%x) %c imm12 %.4x", (unsigned int) dsc->insn_addr, u_bit ? '+' : '-', imm12); if (!u_bit) imm12 = -1 * imm12; /* Rewrite instruction {pli/pld} PC imm12 into: Prepare: tmp[0] <- r0, tmp[1] <- r1, r0 <- pc, r1 <- imm12 {pli/pld} [r0, r1] Cleanup: r0 <- tmp[0], r1 <- tmp[1]. */ dsc->tmp[0] = displaced_read_reg (regs, dsc, 0); dsc->tmp[1] = displaced_read_reg (regs, dsc, 1); pc_val = displaced_read_reg (regs, dsc, ARM_PC_REGNUM); displaced_write_reg (regs, dsc, 0, pc_val, CANNOT_WRITE_PC); displaced_write_reg (regs, dsc, 1, imm12, CANNOT_WRITE_PC); dsc->u.preload.immed = 0; /* {pli/pld} [r0, r1] */ dsc->modinsn[0] = insn1 & 0xfff0; dsc->modinsn[1] = 0xf001; dsc->numinsns = 2; dsc->cleanup = &cleanup_preload; return 0; } /* Preload instructions with register offset. */ static void install_preload_reg(struct gdbarch *gdbarch, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc, unsigned int rn, unsigned int rm) { ULONGEST rn_val, rm_val; /* Preload register-offset instructions: {pli/pld} [rn, rm {, shift}] -> {pli/pld} [r0, r1 {, shift}]. */ dsc->tmp[0] = displaced_read_reg (regs, dsc, 0); dsc->tmp[1] = displaced_read_reg (regs, dsc, 1); rn_val = displaced_read_reg (regs, dsc, rn); rm_val = displaced_read_reg (regs, dsc, rm); displaced_write_reg (regs, dsc, 0, rn_val, CANNOT_WRITE_PC); displaced_write_reg (regs, dsc, 1, rm_val, CANNOT_WRITE_PC); dsc->u.preload.immed = 0; dsc->cleanup = &cleanup_preload; } static int arm_copy_preload_reg (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { unsigned int rn = bits (insn, 16, 19); unsigned int rm = bits (insn, 0, 3); if (!insn_references_pc (insn, 0x000f000ful)) return arm_copy_unmodified (gdbarch, insn, "preload reg", dsc); displaced_debug_printf ("copying preload insn %.8lx", (unsigned long) insn); dsc->modinsn[0] = (insn & 0xfff0fff0) | 0x1; install_preload_reg (gdbarch, regs, dsc, rn, rm); return 0; } /* Copy/cleanup coprocessor load and store instructions. */ static void cleanup_copro_load_store (struct gdbarch *gdbarch, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { ULONGEST rn_val = displaced_read_reg (regs, dsc, 0); displaced_write_reg (regs, dsc, 0, dsc->tmp[0], CANNOT_WRITE_PC); if (dsc->u.ldst.writeback) displaced_write_reg (regs, dsc, dsc->u.ldst.rn, rn_val, LOAD_WRITE_PC); } static void install_copro_load_store (struct gdbarch *gdbarch, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc, int writeback, unsigned int rn) { ULONGEST rn_val; /* Coprocessor load/store instructions: {stc/stc2} [, #+/-imm] (and other immediate addressing modes) -> {stc/stc2} [r0, #+/-imm]. ldc/ldc2 are handled identically. */ dsc->tmp[0] = displaced_read_reg (regs, dsc, 0); rn_val = displaced_read_reg (regs, dsc, rn); /* PC should be 4-byte aligned. */ rn_val = rn_val & 0xfffffffc; displaced_write_reg (regs, dsc, 0, rn_val, CANNOT_WRITE_PC); dsc->u.ldst.writeback = writeback; dsc->u.ldst.rn = rn; dsc->cleanup = &cleanup_copro_load_store; } static int arm_copy_copro_load_store (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { unsigned int rn = bits (insn, 16, 19); if (!insn_references_pc (insn, 0x000f0000ul)) return arm_copy_unmodified (gdbarch, insn, "copro load/store", dsc); displaced_debug_printf ("copying coprocessor load/store insn %.8lx", (unsigned long) insn); dsc->modinsn[0] = insn & 0xfff0ffff; install_copro_load_store (gdbarch, regs, dsc, bit (insn, 25), rn); return 0; } static int thumb2_copy_copro_load_store (struct gdbarch *gdbarch, uint16_t insn1, uint16_t insn2, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { unsigned int rn = bits (insn1, 0, 3); if (rn != ARM_PC_REGNUM) return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "copro load/store", dsc); displaced_debug_printf ("copying coprocessor load/store insn %.4x%.4x", insn1, insn2); dsc->modinsn[0] = insn1 & 0xfff0; dsc->modinsn[1] = insn2; dsc->numinsns = 2; /* This function is called for copying instruction LDC/LDC2/VLDR, which doesn't support writeback, so pass 0. */ install_copro_load_store (gdbarch, regs, dsc, 0, rn); return 0; } /* Clean up branch instructions (actually perform the branch, by setting PC). */ static void cleanup_branch (struct gdbarch *gdbarch, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { uint32_t status = displaced_read_reg (regs, dsc, ARM_PS_REGNUM); int branch_taken = condition_true (dsc->u.branch.cond, status); enum pc_write_style write_pc = dsc->u.branch.exchange ? BX_WRITE_PC : BRANCH_WRITE_PC; if (!branch_taken) return; if (dsc->u.branch.link) { /* The value of LR should be the next insn of current one. In order not to confuse logic handling later insn `bx lr', if current insn mode is Thumb, the bit 0 of LR value should be set to 1. */ ULONGEST next_insn_addr = dsc->insn_addr + dsc->insn_size; if (dsc->is_thumb) next_insn_addr |= 0x1; displaced_write_reg (regs, dsc, ARM_LR_REGNUM, next_insn_addr, CANNOT_WRITE_PC); } displaced_write_reg (regs, dsc, ARM_PC_REGNUM, dsc->u.branch.dest, write_pc); } /* Copy B/BL/BLX instructions with immediate destinations. */ static void install_b_bl_blx (struct gdbarch *gdbarch, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc, unsigned int cond, int exchange, int link, long offset) { /* Implement "BL " as: Preparation: cond <- instruction condition Insn: mov r0, r0 (nop) Cleanup: if (condition true) { r14 <- pc; pc <- label }. B similar, but don't set r14 in cleanup. */ dsc->u.branch.cond = cond; dsc->u.branch.link = link; dsc->u.branch.exchange = exchange; dsc->u.branch.dest = dsc->insn_addr; if (link && exchange) /* For BLX, offset is computed from the Align (PC, 4). */ dsc->u.branch.dest = dsc->u.branch.dest & 0xfffffffc; if (dsc->is_thumb) dsc->u.branch.dest += 4 + offset; else dsc->u.branch.dest += 8 + offset; dsc->cleanup = &cleanup_branch; } static int arm_copy_b_bl_blx (struct gdbarch *gdbarch, uint32_t insn, regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { unsigned int cond = bits (insn, 28, 31); int exchange = (cond == 0xf); int link = exchange || bit (insn, 24); long offset; displaced_debug_printf ("copying %s immediate insn %.8lx", (exchange) ? "blx" : (link) ? "bl" : "b", (unsigned long) insn); if (exchange) /* For BLX, set bit 0 of the destination. The cleanup_branch function will then arrange the switch into Thumb mode. */ offset = (bits (insn, 0, 23) << 2) | (bit (insn, 24) << 1) | 1; else offset = bits (insn, 0, 23) << 2; if (bit (offset, 25)) offset = offset | ~0x3ffffff; dsc->modinsn[0] = ARM_NOP; install_b_bl_blx (gdbarch, regs, dsc, cond, exchange, link, offset); return 0; } static int thumb2_copy_b_bl_blx (struct gdbarch *gdbarch, uint16_t insn1, uint16_t insn2, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { int link = bit (insn2, 14); int exchange = link && !bit (insn2, 12); int cond = INST_AL; long offset = 0; int j1 = bit (insn2, 13); int j2 = bit (insn2, 11); int s = sbits (insn1, 10, 10); int i1 = !(j1 ^ bit (insn1, 10)); int i2 = !(j2 ^ bit (insn1, 10)); if (!link && !exchange) /* B */ { offset = (bits (insn2, 0, 10) << 1); if (bit (insn2, 12)) /* Encoding T4 */ { offset |= (bits (insn1, 0, 9) << 12) | (i2 << 22) | (i1 << 23) | (s << 24); cond = INST_AL; } else /* Encoding T3 */ { offset |= (bits (insn1, 0, 5) << 12) | (j1 << 18) | (j2 << 19) | (s << 20); cond = bits (insn1, 6, 9); } } else { offset = (bits (insn1, 0, 9) << 12); offset |= ((i2 << 22) | (i1 << 23) | (s << 24)); offset |= exchange ? (bits (insn2, 1, 10) << 2) : (bits (insn2, 0, 10) << 1); } displaced_debug_printf ("copying %s insn %.4x %.4x with offset %.8lx", link ? (exchange) ? "blx" : "bl" : "b", insn1, insn2, offset); dsc->modinsn[0] = THUMB_NOP; install_b_bl_blx (gdbarch, regs, dsc, cond, exchange, link, offset); return 0; } /* Copy B Thumb instructions. */ static int thumb_copy_b (struct gdbarch *gdbarch, uint16_t insn, arm_displaced_step_copy_insn_closure *dsc) { unsigned int cond = 0; int offset = 0; unsigned short bit_12_15 = bits (insn, 12, 15); CORE_ADDR from = dsc->insn_addr; if (bit_12_15 == 0xd) { /* offset = SignExtend (imm8:0, 32) */ offset = sbits ((insn << 1), 0, 8); cond = bits (insn, 8, 11); } else if (bit_12_15 == 0xe) /* Encoding T2 */ { offset = sbits ((insn << 1), 0, 11); cond = INST_AL; } displaced_debug_printf ("copying b immediate insn %.4x with offset %d", insn, offset); dsc->u.branch.cond = cond; dsc->u.branch.link = 0; dsc->u.branch.exchange = 0; dsc->u.branch.dest = from + 4 + offset; dsc->modinsn[0] = THUMB_NOP; dsc->cleanup = &cleanup_branch; return 0; } /* Copy BX/BLX with register-specified destinations. */ static void install_bx_blx_reg (struct gdbarch *gdbarch, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc, int link, unsigned int cond, unsigned int rm) { /* Implement {BX,BLX} " as: Preparation: cond <- instruction condition Insn: mov r0, r0 (nop) Cleanup: if (condition true) { r14 <- pc; pc <- dest; }. Don't set r14 in cleanup for BX. */ dsc->u.branch.dest = displaced_read_reg (regs, dsc, rm); dsc->u.branch.cond = cond; dsc->u.branch.link = link; dsc->u.branch.exchange = 1; dsc->cleanup = &cleanup_branch; } static int arm_copy_bx_blx_reg (struct gdbarch *gdbarch, uint32_t insn, regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { unsigned int cond = bits (insn, 28, 31); /* BX: x12xxx1x BLX: x12xxx3x. */ int link = bit (insn, 5); unsigned int rm = bits (insn, 0, 3); displaced_debug_printf ("copying insn %.8lx", (unsigned long) insn); dsc->modinsn[0] = ARM_NOP; install_bx_blx_reg (gdbarch, regs, dsc, link, cond, rm); return 0; } static int thumb_copy_bx_blx_reg (struct gdbarch *gdbarch, uint16_t insn, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { int link = bit (insn, 7); unsigned int rm = bits (insn, 3, 6); displaced_debug_printf ("copying insn %.4x", (unsigned short) insn); dsc->modinsn[0] = THUMB_NOP; install_bx_blx_reg (gdbarch, regs, dsc, link, INST_AL, rm); return 0; } /* Copy/cleanup arithmetic/logic instruction with immediate RHS. */ static void cleanup_alu_imm (struct gdbarch *gdbarch, regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { ULONGEST rd_val = displaced_read_reg (regs, dsc, 0); displaced_write_reg (regs, dsc, 0, dsc->tmp[0], CANNOT_WRITE_PC); displaced_write_reg (regs, dsc, 1, dsc->tmp[1], CANNOT_WRITE_PC); displaced_write_reg (regs, dsc, dsc->rd, rd_val, ALU_WRITE_PC); } static int arm_copy_alu_imm (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { unsigned int rn = bits (insn, 16, 19); unsigned int rd = bits (insn, 12, 15); unsigned int op = bits (insn, 21, 24); int is_mov = (op == 0xd); ULONGEST rd_val, rn_val; if (!insn_references_pc (insn, 0x000ff000ul)) return arm_copy_unmodified (gdbarch, insn, "ALU immediate", dsc); displaced_debug_printf ("copying immediate %s insn %.8lx", is_mov ? "move" : "ALU", (unsigned long) insn); /* Instruction is of form: rd, [rn,] #imm Rewrite as: Preparation: tmp1, tmp2 <- r0, r1; r0, r1 <- rd, rn Insn: r0, r1, #imm Cleanup: rd <- r0; r0 <- tmp1; r1 <- tmp2 */ dsc->tmp[0] = displaced_read_reg (regs, dsc, 0); dsc->tmp[1] = displaced_read_reg (regs, dsc, 1); rn_val = displaced_read_reg (regs, dsc, rn); rd_val = displaced_read_reg (regs, dsc, rd); displaced_write_reg (regs, dsc, 0, rd_val, CANNOT_WRITE_PC); displaced_write_reg (regs, dsc, 1, rn_val, CANNOT_WRITE_PC); dsc->rd = rd; if (is_mov) dsc->modinsn[0] = insn & 0xfff00fff; else dsc->modinsn[0] = (insn & 0xfff00fff) | 0x10000; dsc->cleanup = &cleanup_alu_imm; return 0; } static int thumb2_copy_alu_imm (struct gdbarch *gdbarch, uint16_t insn1, uint16_t insn2, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { unsigned int op = bits (insn1, 5, 8); unsigned int rn, rm, rd; ULONGEST rd_val, rn_val; rn = bits (insn1, 0, 3); /* Rn */ rm = bits (insn2, 0, 3); /* Rm */ rd = bits (insn2, 8, 11); /* Rd */ /* This routine is only called for instruction MOV. */ gdb_assert (op == 0x2 && rn == 0xf); if (rm != ARM_PC_REGNUM && rd != ARM_PC_REGNUM) return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "ALU imm", dsc); displaced_debug_printf ("copying reg %s insn %.4x%.4x", "ALU", insn1, insn2); /* Instruction is of form: rd, [rn,] #imm Rewrite as: Preparation: tmp1, tmp2 <- r0, r1; r0, r1 <- rd, rn Insn: r0, r1, #imm Cleanup: rd <- r0; r0 <- tmp1; r1 <- tmp2 */ dsc->tmp[0] = displaced_read_reg (regs, dsc, 0); dsc->tmp[1] = displaced_read_reg (regs, dsc, 1); rn_val = displaced_read_reg (regs, dsc, rn); rd_val = displaced_read_reg (regs, dsc, rd); displaced_write_reg (regs, dsc, 0, rd_val, CANNOT_WRITE_PC); displaced_write_reg (regs, dsc, 1, rn_val, CANNOT_WRITE_PC); dsc->rd = rd; dsc->modinsn[0] = insn1; dsc->modinsn[1] = ((insn2 & 0xf0f0) | 0x1); dsc->numinsns = 2; dsc->cleanup = &cleanup_alu_imm; return 0; } /* Copy/cleanup arithmetic/logic insns with register RHS. */ static void cleanup_alu_reg (struct gdbarch *gdbarch, regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { ULONGEST rd_val; int i; rd_val = displaced_read_reg (regs, dsc, 0); for (i = 0; i < 3; i++) displaced_write_reg (regs, dsc, i, dsc->tmp[i], CANNOT_WRITE_PC); displaced_write_reg (regs, dsc, dsc->rd, rd_val, ALU_WRITE_PC); } static void install_alu_reg (struct gdbarch *gdbarch, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc, unsigned int rd, unsigned int rn, unsigned int rm) { ULONGEST rd_val, rn_val, rm_val; /* Instruction is of form: rd, [rn,] rm [, ] Rewrite as: Preparation: tmp1, tmp2, tmp3 <- r0, r1, r2; r0, r1, r2 <- rd, rn, rm Insn: r0, [r1,] r2 [, ] Cleanup: rd <- r0; r0, r1, r2 <- tmp1, tmp2, tmp3 */ dsc->tmp[0] = displaced_read_reg (regs, dsc, 0); dsc->tmp[1] = displaced_read_reg (regs, dsc, 1); dsc->tmp[2] = displaced_read_reg (regs, dsc, 2); rd_val = displaced_read_reg (regs, dsc, rd); rn_val = displaced_read_reg (regs, dsc, rn); rm_val = displaced_read_reg (regs, dsc, rm); displaced_write_reg (regs, dsc, 0, rd_val, CANNOT_WRITE_PC); displaced_write_reg (regs, dsc, 1, rn_val, CANNOT_WRITE_PC); displaced_write_reg (regs, dsc, 2, rm_val, CANNOT_WRITE_PC); dsc->rd = rd; dsc->cleanup = &cleanup_alu_reg; } static int arm_copy_alu_reg (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { unsigned int op = bits (insn, 21, 24); int is_mov = (op == 0xd); if (!insn_references_pc (insn, 0x000ff00ful)) return arm_copy_unmodified (gdbarch, insn, "ALU reg", dsc); displaced_debug_printf ("copying reg %s insn %.8lx", is_mov ? "move" : "ALU", (unsigned long) insn); if (is_mov) dsc->modinsn[0] = (insn & 0xfff00ff0) | 0x2; else dsc->modinsn[0] = (insn & 0xfff00ff0) | 0x10002; install_alu_reg (gdbarch, regs, dsc, bits (insn, 12, 15), bits (insn, 16, 19), bits (insn, 0, 3)); return 0; } static int thumb_copy_alu_reg (struct gdbarch *gdbarch, uint16_t insn, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { unsigned rm, rd; rm = bits (insn, 3, 6); rd = (bit (insn, 7) << 3) | bits (insn, 0, 2); if (rd != ARM_PC_REGNUM && rm != ARM_PC_REGNUM) return thumb_copy_unmodified_16bit (gdbarch, insn, "ALU reg", dsc); displaced_debug_printf ("copying ALU reg insn %.4x", (unsigned short) insn); dsc->modinsn[0] = ((insn & 0xff00) | 0x10); install_alu_reg (gdbarch, regs, dsc, rd, rd, rm); return 0; } /* Cleanup/copy arithmetic/logic insns with shifted register RHS. */ static void cleanup_alu_shifted_reg (struct gdbarch *gdbarch, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { ULONGEST rd_val = displaced_read_reg (regs, dsc, 0); int i; for (i = 0; i < 4; i++) displaced_write_reg (regs, dsc, i, dsc->tmp[i], CANNOT_WRITE_PC); displaced_write_reg (regs, dsc, dsc->rd, rd_val, ALU_WRITE_PC); } static void install_alu_shifted_reg (struct gdbarch *gdbarch, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc, unsigned int rd, unsigned int rn, unsigned int rm, unsigned rs) { int i; ULONGEST rd_val, rn_val, rm_val, rs_val; /* Instruction is of form: rd, [rn,] rm, rs Rewrite as: Preparation: tmp1, tmp2, tmp3, tmp4 <- r0, r1, r2, r3 r0, r1, r2, r3 <- rd, rn, rm, rs Insn: r0, r1, r2, r3 Cleanup: tmp5 <- r0 r0, r1, r2, r3 <- tmp1, tmp2, tmp3, tmp4 rd <- tmp5 */ for (i = 0; i < 4; i++) dsc->tmp[i] = displaced_read_reg (regs, dsc, i); rd_val = displaced_read_reg (regs, dsc, rd); rn_val = displaced_read_reg (regs, dsc, rn); rm_val = displaced_read_reg (regs, dsc, rm); rs_val = displaced_read_reg (regs, dsc, rs); displaced_write_reg (regs, dsc, 0, rd_val, CANNOT_WRITE_PC); displaced_write_reg (regs, dsc, 1, rn_val, CANNOT_WRITE_PC); displaced_write_reg (regs, dsc, 2, rm_val, CANNOT_WRITE_PC); displaced_write_reg (regs, dsc, 3, rs_val, CANNOT_WRITE_PC); dsc->rd = rd; dsc->cleanup = &cleanup_alu_shifted_reg; } static int arm_copy_alu_shifted_reg (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { unsigned int op = bits (insn, 21, 24); int is_mov = (op == 0xd); unsigned int rd, rn, rm, rs; if (!insn_references_pc (insn, 0x000fff0ful)) return arm_copy_unmodified (gdbarch, insn, "ALU shifted reg", dsc); displaced_debug_printf ("copying shifted reg %s insn %.8lx", is_mov ? "move" : "ALU", (unsigned long) insn); rn = bits (insn, 16, 19); rm = bits (insn, 0, 3); rs = bits (insn, 8, 11); rd = bits (insn, 12, 15); if (is_mov) dsc->modinsn[0] = (insn & 0xfff000f0) | 0x302; else dsc->modinsn[0] = (insn & 0xfff000f0) | 0x10302; install_alu_shifted_reg (gdbarch, regs, dsc, rd, rn, rm, rs); return 0; } /* Clean up load instructions. */ static void cleanup_load (struct gdbarch *gdbarch, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { ULONGEST rt_val, rt_val2 = 0, rn_val; rt_val = displaced_read_reg (regs, dsc, 0); if (dsc->u.ldst.xfersize == 8) rt_val2 = displaced_read_reg (regs, dsc, 1); rn_val = displaced_read_reg (regs, dsc, 2); displaced_write_reg (regs, dsc, 0, dsc->tmp[0], CANNOT_WRITE_PC); if (dsc->u.ldst.xfersize > 4) displaced_write_reg (regs, dsc, 1, dsc->tmp[1], CANNOT_WRITE_PC); displaced_write_reg (regs, dsc, 2, dsc->tmp[2], CANNOT_WRITE_PC); if (!dsc->u.ldst.immed) displaced_write_reg (regs, dsc, 3, dsc->tmp[3], CANNOT_WRITE_PC); /* Handle register writeback. */ if (dsc->u.ldst.writeback) displaced_write_reg (regs, dsc, dsc->u.ldst.rn, rn_val, CANNOT_WRITE_PC); /* Put result in right place. */ displaced_write_reg (regs, dsc, dsc->rd, rt_val, LOAD_WRITE_PC); if (dsc->u.ldst.xfersize == 8) displaced_write_reg (regs, dsc, dsc->rd + 1, rt_val2, LOAD_WRITE_PC); } /* Clean up store instructions. */ static void cleanup_store (struct gdbarch *gdbarch, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { ULONGEST rn_val = displaced_read_reg (regs, dsc, 2); displaced_write_reg (regs, dsc, 0, dsc->tmp[0], CANNOT_WRITE_PC); if (dsc->u.ldst.xfersize > 4) displaced_write_reg (regs, dsc, 1, dsc->tmp[1], CANNOT_WRITE_PC); displaced_write_reg (regs, dsc, 2, dsc->tmp[2], CANNOT_WRITE_PC); if (!dsc->u.ldst.immed) displaced_write_reg (regs, dsc, 3, dsc->tmp[3], CANNOT_WRITE_PC); if (!dsc->u.ldst.restore_r4) displaced_write_reg (regs, dsc, 4, dsc->tmp[4], CANNOT_WRITE_PC); /* Writeback. */ if (dsc->u.ldst.writeback) displaced_write_reg (regs, dsc, dsc->u.ldst.rn, rn_val, CANNOT_WRITE_PC); } /* Copy "extra" load/store instructions. These are halfword/doubleword transfers, which have a different encoding to byte/word transfers. */ static int arm_copy_extra_ld_st (struct gdbarch *gdbarch, uint32_t insn, int unprivileged, regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { unsigned int op1 = bits (insn, 20, 24); unsigned int op2 = bits (insn, 5, 6); unsigned int rt = bits (insn, 12, 15); unsigned int rn = bits (insn, 16, 19); unsigned int rm = bits (insn, 0, 3); char load[12] = {0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1}; char bytesize[12] = {2, 2, 2, 2, 8, 1, 8, 1, 8, 2, 8, 2}; int immed = (op1 & 0x4) != 0; int opcode; ULONGEST rt_val, rt_val2 = 0, rn_val, rm_val = 0; if (!insn_references_pc (insn, 0x000ff00ful)) return arm_copy_unmodified (gdbarch, insn, "extra load/store", dsc); displaced_debug_printf ("copying %sextra load/store insn %.8lx", unprivileged ? "unprivileged " : "", (unsigned long) insn); opcode = ((op2 << 2) | (op1 & 0x1) | ((op1 & 0x4) >> 1)) - 4; if (opcode < 0) internal_error (_("copy_extra_ld_st: instruction decode error")); dsc->tmp[0] = displaced_read_reg (regs, dsc, 0); dsc->tmp[1] = displaced_read_reg (regs, dsc, 1); dsc->tmp[2] = displaced_read_reg (regs, dsc, 2); if (!immed) dsc->tmp[3] = displaced_read_reg (regs, dsc, 3); rt_val = displaced_read_reg (regs, dsc, rt); if (bytesize[opcode] == 8) rt_val2 = displaced_read_reg (regs, dsc, rt + 1); rn_val = displaced_read_reg (regs, dsc, rn); if (!immed) rm_val = displaced_read_reg (regs, dsc, rm); displaced_write_reg (regs, dsc, 0, rt_val, CANNOT_WRITE_PC); if (bytesize[opcode] == 8) displaced_write_reg (regs, dsc, 1, rt_val2, CANNOT_WRITE_PC); displaced_write_reg (regs, dsc, 2, rn_val, CANNOT_WRITE_PC); if (!immed) displaced_write_reg (regs, dsc, 3, rm_val, CANNOT_WRITE_PC); dsc->rd = rt; dsc->u.ldst.xfersize = bytesize[opcode]; dsc->u.ldst.rn = rn; dsc->u.ldst.immed = immed; dsc->u.ldst.writeback = bit (insn, 24) == 0 || bit (insn, 21) != 0; dsc->u.ldst.restore_r4 = 0; if (immed) /* {ldr,str} rt, [rt2,] [rn, #imm] -> {ldr,str} r0, [r1,] [r2, #imm]. */ dsc->modinsn[0] = (insn & 0xfff00fff) | 0x20000; else /* {ldr,str} rt, [rt2,] [rn, +/-rm] -> {ldr,str} r0, [r1,] [r2, +/-r3]. */ dsc->modinsn[0] = (insn & 0xfff00ff0) | 0x20003; dsc->cleanup = load[opcode] ? &cleanup_load : &cleanup_store; return 0; } /* Copy byte/half word/word loads and stores. */ static void install_load_store (struct gdbarch *gdbarch, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc, int load, int immed, int writeback, int size, int usermode, int rt, int rm, int rn) { ULONGEST rt_val, rn_val, rm_val = 0; dsc->tmp[0] = displaced_read_reg (regs, dsc, 0); dsc->tmp[2] = displaced_read_reg (regs, dsc, 2); if (!immed) dsc->tmp[3] = displaced_read_reg (regs, dsc, 3); if (!load) dsc->tmp[4] = displaced_read_reg (regs, dsc, 4); rt_val = displaced_read_reg (regs, dsc, rt); rn_val = displaced_read_reg (regs, dsc, rn); if (!immed) rm_val = displaced_read_reg (regs, dsc, rm); displaced_write_reg (regs, dsc, 0, rt_val, CANNOT_WRITE_PC); displaced_write_reg (regs, dsc, 2, rn_val, CANNOT_WRITE_PC); if (!immed) displaced_write_reg (regs, dsc, 3, rm_val, CANNOT_WRITE_PC); dsc->rd = rt; dsc->u.ldst.xfersize = size; dsc->u.ldst.rn = rn; dsc->u.ldst.immed = immed; dsc->u.ldst.writeback = writeback; /* To write PC we can do: Before this sequence of instructions: r0 is the PC value got from displaced_read_reg, so r0 = from + 8; r2 is the Rn value got from displaced_read_reg. Insn1: push {pc} Write address of STR instruction + offset on stack Insn2: pop {r4} Read it back from stack, r4 = addr(Insn1) + offset Insn3: sub r4, r4, pc r4 = addr(Insn1) + offset - pc = addr(Insn1) + offset - addr(Insn3) - 8 = offset - 16 Insn4: add r4, r4, #8 r4 = offset - 8 Insn5: add r0, r0, r4 r0 = from + 8 + offset - 8 = from + offset Insn6: str r0, [r2, #imm] (or str r0, [r2, r3]) Otherwise we don't know what value to write for PC, since the offset is architecture-dependent (sometimes PC+8, sometimes PC+12). More details of this can be found in Section "Saving from r15" in http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0204g/Cihbjifh.html */ dsc->cleanup = load ? &cleanup_load : &cleanup_store; } static int thumb2_copy_load_literal (struct gdbarch *gdbarch, uint16_t insn1, uint16_t insn2, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc, int size) { unsigned int u_bit = bit (insn1, 7); unsigned int rt = bits (insn2, 12, 15); int imm12 = bits (insn2, 0, 11); ULONGEST pc_val; displaced_debug_printf ("copying ldr pc (0x%x) R%d %c imm12 %.4x", (unsigned int) dsc->insn_addr, rt, u_bit ? '+' : '-', imm12); if (!u_bit) imm12 = -1 * imm12; /* Rewrite instruction LDR Rt imm12 into: Prepare: tmp[0] <- r0, tmp[1] <- r2, tmp[2] <- r3, r2 <- pc, r3 <- imm12 LDR R0, R2, R3, Cleanup: rt <- r0, r0 <- tmp[0], r2 <- tmp[1], r3 <- tmp[2]. */ dsc->tmp[0] = displaced_read_reg (regs, dsc, 0); dsc->tmp[2] = displaced_read_reg (regs, dsc, 2); dsc->tmp[3] = displaced_read_reg (regs, dsc, 3); pc_val = displaced_read_reg (regs, dsc, ARM_PC_REGNUM); pc_val = pc_val & 0xfffffffc; displaced_write_reg (regs, dsc, 2, pc_val, CANNOT_WRITE_PC); displaced_write_reg (regs, dsc, 3, imm12, CANNOT_WRITE_PC); dsc->rd = rt; dsc->u.ldst.xfersize = size; dsc->u.ldst.immed = 0; dsc->u.ldst.writeback = 0; dsc->u.ldst.restore_r4 = 0; /* LDR R0, R2, R3 */ dsc->modinsn[0] = 0xf852; dsc->modinsn[1] = 0x3; dsc->numinsns = 2; dsc->cleanup = &cleanup_load; return 0; } static int thumb2_copy_load_reg_imm (struct gdbarch *gdbarch, uint16_t insn1, uint16_t insn2, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc, int writeback, int immed) { unsigned int rt = bits (insn2, 12, 15); unsigned int rn = bits (insn1, 0, 3); unsigned int rm = bits (insn2, 0, 3); /* Only valid if !immed. */ /* In LDR (register), there is also a register Rm, which is not allowed to be PC, so we don't have to check it. */ if (rt != ARM_PC_REGNUM && rn != ARM_PC_REGNUM) return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "load", dsc); displaced_debug_printf ("copying ldr r%d [r%d] insn %.4x%.4x", rt, rn, insn1, insn2); install_load_store (gdbarch, regs, dsc, 1, immed, writeback, 4, 0, rt, rm, rn); dsc->u.ldst.restore_r4 = 0; if (immed) /* ldr[b] rt, [rn, #imm], etc. -> ldr[b] r0, [r2, #imm]. */ { dsc->modinsn[0] = (insn1 & 0xfff0) | 0x2; dsc->modinsn[1] = insn2 & 0x0fff; } else /* ldr[b] rt, [rn, rm], etc. -> ldr[b] r0, [r2, r3]. */ { dsc->modinsn[0] = (insn1 & 0xfff0) | 0x2; dsc->modinsn[1] = (insn2 & 0x0ff0) | 0x3; } dsc->numinsns = 2; return 0; } static int arm_copy_ldr_str_ldrb_strb (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc, int load, int size, int usermode) { int immed = !bit (insn, 25); int writeback = (bit (insn, 24) == 0 || bit (insn, 21) != 0); unsigned int rt = bits (insn, 12, 15); unsigned int rn = bits (insn, 16, 19); unsigned int rm = bits (insn, 0, 3); /* Only valid if !immed. */ if (!insn_references_pc (insn, 0x000ff00ful)) return arm_copy_unmodified (gdbarch, insn, "load/store", dsc); displaced_debug_printf ("copying %s%s r%d [r%d] insn %.8lx", load ? (size == 1 ? "ldrb" : "ldr") : (size == 1 ? "strb" : "str"), usermode ? "t" : "", rt, rn, (unsigned long) insn); install_load_store (gdbarch, regs, dsc, load, immed, writeback, size, usermode, rt, rm, rn); if (load || rt != ARM_PC_REGNUM) { dsc->u.ldst.restore_r4 = 0; if (immed) /* {ldr,str}[b] rt, [rn, #imm], etc. -> {ldr,str}[b] r0, [r2, #imm]. */ dsc->modinsn[0] = (insn & 0xfff00fff) | 0x20000; else /* {ldr,str}[b] rt, [rn, rm], etc. -> {ldr,str}[b] r0, [r2, r3]. */ dsc->modinsn[0] = (insn & 0xfff00ff0) | 0x20003; } else { /* We need to use r4 as scratch. Make sure it's restored afterwards. */ dsc->u.ldst.restore_r4 = 1; dsc->modinsn[0] = 0xe92d8000; /* push {pc} */ dsc->modinsn[1] = 0xe8bd0010; /* pop {r4} */ dsc->modinsn[2] = 0xe044400f; /* sub r4, r4, pc. */ dsc->modinsn[3] = 0xe2844008; /* add r4, r4, #8. */ dsc->modinsn[4] = 0xe0800004; /* add r0, r0, r4. */ /* As above. */ if (immed) dsc->modinsn[5] = (insn & 0xfff00fff) | 0x20000; else dsc->modinsn[5] = (insn & 0xfff00ff0) | 0x20003; dsc->numinsns = 6; } dsc->cleanup = load ? &cleanup_load : &cleanup_store; return 0; } /* Cleanup LDM instructions with fully-populated register list. This is an unfortunate corner case: it's impossible to implement correctly by modifying the instruction. The issue is as follows: we have an instruction, ldm rN, {r0-r15} which we must rewrite to avoid loading PC. A possible solution would be to do the load in two halves, something like (with suitable cleanup afterwards): mov r8, rN ldm[id][ab] r8!, {r0-r7} str r7, ldm[id][ab] r8, {r7-r14} but at present there's no suitable place for , since the scratch space is overwritten before the cleanup routine is called. For now, we simply emulate the instruction. */ static void cleanup_block_load_all (struct gdbarch *gdbarch, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { int inc = dsc->u.block.increment; int bump_before = dsc->u.block.before ? (inc ? 4 : -4) : 0; int bump_after = dsc->u.block.before ? 0 : (inc ? 4 : -4); uint32_t regmask = dsc->u.block.regmask; int regno = inc ? 0 : 15; CORE_ADDR xfer_addr = dsc->u.block.xfer_addr; int exception_return = dsc->u.block.load && dsc->u.block.user && (regmask & 0x8000) != 0; uint32_t status = displaced_read_reg (regs, dsc, ARM_PS_REGNUM); int do_transfer = condition_true (dsc->u.block.cond, status); enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); if (!do_transfer) return; /* If the instruction is ldm rN, {...pc}^, I don't think there's anything sensible we can do here. Complain loudly. */ if (exception_return) error (_("Cannot single-step exception return")); /* We don't handle any stores here for now. */ gdb_assert (dsc->u.block.load != 0); displaced_debug_printf ("emulating block transfer: %s %s %s", dsc->u.block.load ? "ldm" : "stm", dsc->u.block.increment ? "inc" : "dec", dsc->u.block.before ? "before" : "after"); while (regmask) { uint32_t memword; if (inc) while (regno <= ARM_PC_REGNUM && (regmask & (1 << regno)) == 0) regno++; else while (regno >= 0 && (regmask & (1 << regno)) == 0) regno--; xfer_addr += bump_before; memword = read_memory_unsigned_integer (xfer_addr, 4, byte_order); displaced_write_reg (regs, dsc, regno, memword, LOAD_WRITE_PC); xfer_addr += bump_after; regmask &= ~(1 << regno); } if (dsc->u.block.writeback) displaced_write_reg (regs, dsc, dsc->u.block.rn, xfer_addr, CANNOT_WRITE_PC); } /* Clean up an STM which included the PC in the register list. */ static void cleanup_block_store_pc (struct gdbarch *gdbarch, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { uint32_t status = displaced_read_reg (regs, dsc, ARM_PS_REGNUM); int store_executed = condition_true (dsc->u.block.cond, status); CORE_ADDR pc_stored_at, transferred_regs = count_one_bits (dsc->u.block.regmask); CORE_ADDR stm_insn_addr; uint32_t pc_val; long offset; enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); /* If condition code fails, there's nothing else to do. */ if (!store_executed) return; if (dsc->u.block.increment) { pc_stored_at = dsc->u.block.xfer_addr + 4 * transferred_regs; if (dsc->u.block.before) pc_stored_at += 4; } else { pc_stored_at = dsc->u.block.xfer_addr; if (dsc->u.block.before) pc_stored_at -= 4; } pc_val = read_memory_unsigned_integer (pc_stored_at, 4, byte_order); stm_insn_addr = dsc->scratch_base; offset = pc_val - stm_insn_addr; displaced_debug_printf ("detected PC offset %.8lx for STM instruction", offset); /* Rewrite the stored PC to the proper value for the non-displaced original instruction. */ write_memory_unsigned_integer (pc_stored_at, 4, byte_order, dsc->insn_addr + offset); } /* Clean up an LDM which includes the PC in the register list. We clumped all the registers in the transferred list into a contiguous range r0...rX (to avoid loading PC directly and losing control of the debugged program), so we must undo that here. */ static void cleanup_block_load_pc (struct gdbarch *gdbarch, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { uint32_t status = displaced_read_reg (regs, dsc, ARM_PS_REGNUM); int load_executed = condition_true (dsc->u.block.cond, status); unsigned int mask = dsc->u.block.regmask, write_reg = ARM_PC_REGNUM; unsigned int regs_loaded = count_one_bits (mask); unsigned int num_to_shuffle = regs_loaded, clobbered; /* The method employed here will fail if the register list is fully populated (we need to avoid loading PC directly). */ gdb_assert (num_to_shuffle < 16); if (!load_executed) return; clobbered = (1 << num_to_shuffle) - 1; while (num_to_shuffle > 0) { if ((mask & (1 << write_reg)) != 0) { unsigned int read_reg = num_to_shuffle - 1; if (read_reg != write_reg) { ULONGEST rval = displaced_read_reg (regs, dsc, read_reg); displaced_write_reg (regs, dsc, write_reg, rval, LOAD_WRITE_PC); displaced_debug_printf ("LDM: move loaded register r%d to r%d", read_reg, write_reg); } else displaced_debug_printf ("LDM: register r%d already in the right " "place", write_reg); clobbered &= ~(1 << write_reg); num_to_shuffle--; } write_reg--; } /* Restore any registers we scribbled over. */ for (write_reg = 0; clobbered != 0; write_reg++) { if ((clobbered & (1 << write_reg)) != 0) { displaced_write_reg (regs, dsc, write_reg, dsc->tmp[write_reg], CANNOT_WRITE_PC); displaced_debug_printf ("LDM: restored clobbered register r%d", write_reg); clobbered &= ~(1 << write_reg); } } /* Perform register writeback manually. */ if (dsc->u.block.writeback) { ULONGEST new_rn_val = dsc->u.block.xfer_addr; if (dsc->u.block.increment) new_rn_val += regs_loaded * 4; else new_rn_val -= regs_loaded * 4; displaced_write_reg (regs, dsc, dsc->u.block.rn, new_rn_val, CANNOT_WRITE_PC); } } /* Handle ldm/stm, apart from some tricky cases which are unlikely to occur in user-level code (in particular exception return, ldm rn, {...pc}^). */ static int arm_copy_block_xfer (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { int load = bit (insn, 20); int user = bit (insn, 22); int increment = bit (insn, 23); int before = bit (insn, 24); int writeback = bit (insn, 21); int rn = bits (insn, 16, 19); /* Block transfers which don't mention PC can be run directly out-of-line. */ if (rn != ARM_PC_REGNUM && (insn & 0x8000) == 0) return arm_copy_unmodified (gdbarch, insn, "ldm/stm", dsc); if (rn == ARM_PC_REGNUM) { warning (_("displaced: Unpredictable LDM or STM with " "base register r15")); return arm_copy_unmodified (gdbarch, insn, "unpredictable ldm/stm", dsc); } displaced_debug_printf ("copying block transfer insn %.8lx", (unsigned long) insn); dsc->u.block.xfer_addr = displaced_read_reg (regs, dsc, rn); dsc->u.block.rn = rn; dsc->u.block.load = load; dsc->u.block.user = user; dsc->u.block.increment = increment; dsc->u.block.before = before; dsc->u.block.writeback = writeback; dsc->u.block.cond = bits (insn, 28, 31); dsc->u.block.regmask = insn & 0xffff; if (load) { if ((insn & 0xffff) == 0xffff) { /* LDM with a fully-populated register list. This case is particularly tricky. Implement for now by fully emulating the instruction (which might not behave perfectly in all cases, but these instructions should be rare enough for that not to matter too much). */ dsc->modinsn[0] = ARM_NOP; dsc->cleanup = &cleanup_block_load_all; } else { /* LDM of a list of registers which includes PC. Implement by rewriting the list of registers to be transferred into a contiguous chunk r0...rX before doing the transfer, then shuffling registers into the correct places in the cleanup routine. */ unsigned int regmask = insn & 0xffff; unsigned int num_in_list = count_one_bits (regmask), new_regmask; unsigned int i; for (i = 0; i < num_in_list; i++) dsc->tmp[i] = displaced_read_reg (regs, dsc, i); /* Writeback makes things complicated. We need to avoid clobbering the base register with one of the registers in our modified register list, but just using a different register can't work in all cases, e.g.: ldm r14!, {r0-r13,pc} which would need to be rewritten as: ldm rN!, {r0-r14} but that can't work, because there's no free register for N. Solve this by turning off the writeback bit, and emulating writeback manually in the cleanup routine. */ if (writeback) insn &= ~(1 << 21); new_regmask = (1 << num_in_list) - 1; displaced_debug_printf ("LDM r%d%s, {..., pc}: original reg list " "%.4x, modified list %.4x", rn, writeback ? "!" : "", (int) insn & 0xffff, new_regmask); dsc->modinsn[0] = (insn & ~0xffff) | (new_regmask & 0xffff); dsc->cleanup = &cleanup_block_load_pc; } } else { /* STM of a list of registers which includes PC. Run the instruction as-is, but out of line: this will store the wrong value for the PC, so we must manually fix up the memory in the cleanup routine. Doing things this way has the advantage that we can auto-detect the offset of the PC write (which is architecture-dependent) in the cleanup routine. */ dsc->modinsn[0] = insn; dsc->cleanup = &cleanup_block_store_pc; } return 0; } static int thumb2_copy_block_xfer (struct gdbarch *gdbarch, uint16_t insn1, uint16_t insn2, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { int rn = bits (insn1, 0, 3); int load = bit (insn1, 4); int writeback = bit (insn1, 5); /* Block transfers which don't mention PC can be run directly out-of-line. */ if (rn != ARM_PC_REGNUM && (insn2 & 0x8000) == 0) return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "ldm/stm", dsc); if (rn == ARM_PC_REGNUM) { warning (_("displaced: Unpredictable LDM or STM with " "base register r15")); return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "unpredictable ldm/stm", dsc); } displaced_debug_printf ("copying block transfer insn %.4x%.4x", insn1, insn2); /* Clear bit 13, since it should be always zero. */ dsc->u.block.regmask = (insn2 & 0xdfff); dsc->u.block.rn = rn; dsc->u.block.load = load; dsc->u.block.user = 0; dsc->u.block.increment = bit (insn1, 7); dsc->u.block.before = bit (insn1, 8); dsc->u.block.writeback = writeback; dsc->u.block.cond = INST_AL; dsc->u.block.xfer_addr = displaced_read_reg (regs, dsc, rn); if (load) { if (dsc->u.block.regmask == 0xffff) { /* This branch is impossible to happen. */ gdb_assert (0); } else { unsigned int regmask = dsc->u.block.regmask; unsigned int num_in_list = count_one_bits (regmask), new_regmask; unsigned int i; for (i = 0; i < num_in_list; i++) dsc->tmp[i] = displaced_read_reg (regs, dsc, i); if (writeback) insn1 &= ~(1 << 5); new_regmask = (1 << num_in_list) - 1; displaced_debug_printf ("LDM r%d%s, {..., pc}: original reg list " "%.4x, modified list %.4x", rn, writeback ? "!" : "", (int) dsc->u.block.regmask, new_regmask); dsc->modinsn[0] = insn1; dsc->modinsn[1] = (new_regmask & 0xffff); dsc->numinsns = 2; dsc->cleanup = &cleanup_block_load_pc; } } else { dsc->modinsn[0] = insn1; dsc->modinsn[1] = insn2; dsc->numinsns = 2; dsc->cleanup = &cleanup_block_store_pc; } return 0; } /* Wrapper over read_memory_unsigned_integer for use in arm_get_next_pcs. This is used to avoid a dependency on BFD's bfd_endian enum. */ ULONGEST arm_get_next_pcs_read_memory_unsigned_integer (CORE_ADDR memaddr, int len, int byte_order) { return read_memory_unsigned_integer (memaddr, len, (enum bfd_endian) byte_order); } /* Wrapper over gdbarch_addr_bits_remove for use in arm_get_next_pcs. */ CORE_ADDR arm_get_next_pcs_addr_bits_remove (struct arm_get_next_pcs *self, CORE_ADDR val) { return gdbarch_addr_bits_remove (self->regcache->arch (), val); } /* Wrapper over syscall_next_pc for use in get_next_pcs. */ static CORE_ADDR arm_get_next_pcs_syscall_next_pc (struct arm_get_next_pcs *self) { return 0; } /* Wrapper over arm_is_thumb for use in arm_get_next_pcs. */ int arm_get_next_pcs_is_thumb (struct arm_get_next_pcs *self) { return arm_is_thumb (self->regcache); } /* single_step() is called just before we want to resume the inferior, if we want to single-step it but there is no hardware or kernel single-step support. We find the target of the coming instructions and breakpoint them. */ std::vector arm_software_single_step (struct regcache *regcache) { struct gdbarch *gdbarch = regcache->arch (); struct arm_get_next_pcs next_pcs_ctx; arm_get_next_pcs_ctor (&next_pcs_ctx, &arm_get_next_pcs_ops, gdbarch_byte_order (gdbarch), gdbarch_byte_order_for_code (gdbarch), 0, regcache); std::vector next_pcs = arm_get_next_pcs (&next_pcs_ctx); for (CORE_ADDR &pc_ref : next_pcs) pc_ref = gdbarch_addr_bits_remove (gdbarch, pc_ref); return next_pcs; } /* Cleanup/copy SVC (SWI) instructions. These two functions are overridden for Linux, where some SVC instructions must be treated specially. */ static void cleanup_svc (struct gdbarch *gdbarch, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { CORE_ADDR resume_addr = dsc->insn_addr + dsc->insn_size; displaced_debug_printf ("cleanup for svc, resume at %.8lx", (unsigned long) resume_addr); displaced_write_reg (regs, dsc, ARM_PC_REGNUM, resume_addr, BRANCH_WRITE_PC); } /* Common copy routine for svc instruction. */ static int install_svc (struct gdbarch *gdbarch, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { /* Preparation: none. Insn: unmodified svc. Cleanup: pc <- insn_addr + insn_size. */ /* Pretend we wrote to the PC, so cleanup doesn't set PC to the next instruction. */ dsc->wrote_to_pc = 1; /* Allow OS-specific code to override SVC handling. */ if (dsc->u.svc.copy_svc_os) return dsc->u.svc.copy_svc_os (gdbarch, regs, dsc); else { dsc->cleanup = &cleanup_svc; return 0; } } static int arm_copy_svc (struct gdbarch *gdbarch, uint32_t insn, regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { displaced_debug_printf ("copying svc insn %.8lx", (unsigned long) insn); dsc->modinsn[0] = insn; return install_svc (gdbarch, regs, dsc); } static int thumb_copy_svc (struct gdbarch *gdbarch, uint16_t insn, regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { displaced_debug_printf ("copying svc insn %.4x", insn); dsc->modinsn[0] = insn; return install_svc (gdbarch, regs, dsc); } /* Copy undefined instructions. */ static int arm_copy_undef (struct gdbarch *gdbarch, uint32_t insn, arm_displaced_step_copy_insn_closure *dsc) { displaced_debug_printf ("copying undefined insn %.8lx", (unsigned long) insn); dsc->modinsn[0] = insn; return 0; } static int thumb_32bit_copy_undef (struct gdbarch *gdbarch, uint16_t insn1, uint16_t insn2, arm_displaced_step_copy_insn_closure *dsc) { displaced_debug_printf ("copying undefined insn %.4x %.4x", (unsigned short) insn1, (unsigned short) insn2); dsc->modinsn[0] = insn1; dsc->modinsn[1] = insn2; dsc->numinsns = 2; return 0; } /* Copy unpredictable instructions. */ static int arm_copy_unpred (struct gdbarch *gdbarch, uint32_t insn, arm_displaced_step_copy_insn_closure *dsc) { displaced_debug_printf ("copying unpredictable insn %.8lx", (unsigned long) insn); dsc->modinsn[0] = insn; return 0; } /* The decode_* functions are instruction decoding helpers. They mostly follow the presentation in the ARM ARM. */ static int arm_decode_misc_memhint_neon (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { unsigned int op1 = bits (insn, 20, 26), op2 = bits (insn, 4, 7); unsigned int rn = bits (insn, 16, 19); if (op1 == 0x10 && (op2 & 0x2) == 0x0 && (rn & 0x1) == 0x0) return arm_copy_unmodified (gdbarch, insn, "cps", dsc); else if (op1 == 0x10 && op2 == 0x0 && (rn & 0x1) == 0x1) return arm_copy_unmodified (gdbarch, insn, "setend", dsc); else if ((op1 & 0x60) == 0x20) return arm_copy_unmodified (gdbarch, insn, "neon dataproc", dsc); else if ((op1 & 0x71) == 0x40) return arm_copy_unmodified (gdbarch, insn, "neon elt/struct load/store", dsc); else if ((op1 & 0x77) == 0x41) return arm_copy_unmodified (gdbarch, insn, "unallocated mem hint", dsc); else if ((op1 & 0x77) == 0x45) return arm_copy_preload (gdbarch, insn, regs, dsc); /* pli. */ else if ((op1 & 0x77) == 0x51) { if (rn != 0xf) return arm_copy_preload (gdbarch, insn, regs, dsc); /* pld/pldw. */ else return arm_copy_unpred (gdbarch, insn, dsc); } else if ((op1 & 0x77) == 0x55) return arm_copy_preload (gdbarch, insn, regs, dsc); /* pld/pldw. */ else if (op1 == 0x57) switch (op2) { case 0x1: return arm_copy_unmodified (gdbarch, insn, "clrex", dsc); case 0x4: return arm_copy_unmodified (gdbarch, insn, "dsb", dsc); case 0x5: return arm_copy_unmodified (gdbarch, insn, "dmb", dsc); case 0x6: return arm_copy_unmodified (gdbarch, insn, "isb", dsc); default: return arm_copy_unpred (gdbarch, insn, dsc); } else if ((op1 & 0x63) == 0x43) return arm_copy_unpred (gdbarch, insn, dsc); else if ((op2 & 0x1) == 0x0) switch (op1 & ~0x80) { case 0x61: return arm_copy_unmodified (gdbarch, insn, "unallocated mem hint", dsc); case 0x65: return arm_copy_preload_reg (gdbarch, insn, regs, dsc); /* pli reg. */ case 0x71: case 0x75: /* pld/pldw reg. */ return arm_copy_preload_reg (gdbarch, insn, regs, dsc); case 0x63: case 0x67: case 0x73: case 0x77: return arm_copy_unpred (gdbarch, insn, dsc); default: return arm_copy_undef (gdbarch, insn, dsc); } else return arm_copy_undef (gdbarch, insn, dsc); /* Probably unreachable. */ } static int arm_decode_unconditional (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { if (bit (insn, 27) == 0) return arm_decode_misc_memhint_neon (gdbarch, insn, regs, dsc); /* Switch on bits: 0bxxxxx321xxx0xxxxxxxxxxxxxxxxxxxx. */ else switch (((insn & 0x7000000) >> 23) | ((insn & 0x100000) >> 20)) { case 0x0: case 0x2: return arm_copy_unmodified (gdbarch, insn, "srs", dsc); case 0x1: case 0x3: return arm_copy_unmodified (gdbarch, insn, "rfe", dsc); case 0x4: case 0x5: case 0x6: case 0x7: return arm_copy_b_bl_blx (gdbarch, insn, regs, dsc); case 0x8: switch ((insn & 0xe00000) >> 21) { case 0x1: case 0x3: case 0x4: case 0x5: case 0x6: case 0x7: /* stc/stc2. */ return arm_copy_copro_load_store (gdbarch, insn, regs, dsc); case 0x2: return arm_copy_unmodified (gdbarch, insn, "mcrr/mcrr2", dsc); default: return arm_copy_undef (gdbarch, insn, dsc); } case 0x9: { int rn_f = (bits (insn, 16, 19) == 0xf); switch ((insn & 0xe00000) >> 21) { case 0x1: case 0x3: /* ldc/ldc2 imm (undefined for rn == pc). */ return rn_f ? arm_copy_undef (gdbarch, insn, dsc) : arm_copy_copro_load_store (gdbarch, insn, regs, dsc); case 0x2: return arm_copy_unmodified (gdbarch, insn, "mrrc/mrrc2", dsc); case 0x4: case 0x5: case 0x6: case 0x7: /* ldc/ldc2 lit (undefined for rn != pc). */ return rn_f ? arm_copy_copro_load_store (gdbarch, insn, regs, dsc) : arm_copy_undef (gdbarch, insn, dsc); default: return arm_copy_undef (gdbarch, insn, dsc); } } case 0xa: return arm_copy_unmodified (gdbarch, insn, "stc/stc2", dsc); case 0xb: if (bits (insn, 16, 19) == 0xf) /* ldc/ldc2 lit. */ return arm_copy_copro_load_store (gdbarch, insn, regs, dsc); else return arm_copy_undef (gdbarch, insn, dsc); case 0xc: if (bit (insn, 4)) return arm_copy_unmodified (gdbarch, insn, "mcr/mcr2", dsc); else return arm_copy_unmodified (gdbarch, insn, "cdp/cdp2", dsc); case 0xd: if (bit (insn, 4)) return arm_copy_unmodified (gdbarch, insn, "mrc/mrc2", dsc); else return arm_copy_unmodified (gdbarch, insn, "cdp/cdp2", dsc); default: return arm_copy_undef (gdbarch, insn, dsc); } } /* Decode miscellaneous instructions in dp/misc encoding space. */ static int arm_decode_miscellaneous (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { unsigned int op2 = bits (insn, 4, 6); unsigned int op = bits (insn, 21, 22); switch (op2) { case 0x0: return arm_copy_unmodified (gdbarch, insn, "mrs/msr", dsc); case 0x1: if (op == 0x1) /* bx. */ return arm_copy_bx_blx_reg (gdbarch, insn, regs, dsc); else if (op == 0x3) return arm_copy_unmodified (gdbarch, insn, "clz", dsc); else return arm_copy_undef (gdbarch, insn, dsc); case 0x2: if (op == 0x1) /* Not really supported. */ return arm_copy_unmodified (gdbarch, insn, "bxj", dsc); else return arm_copy_undef (gdbarch, insn, dsc); case 0x3: if (op == 0x1) return arm_copy_bx_blx_reg (gdbarch, insn, regs, dsc); /* blx register. */ else return arm_copy_undef (gdbarch, insn, dsc); case 0x5: return arm_copy_unmodified (gdbarch, insn, "saturating add/sub", dsc); case 0x7: if (op == 0x1) return arm_copy_unmodified (gdbarch, insn, "bkpt", dsc); else if (op == 0x3) /* Not really supported. */ return arm_copy_unmodified (gdbarch, insn, "smc", dsc); /* Fall through. */ default: return arm_copy_undef (gdbarch, insn, dsc); } } static int arm_decode_dp_misc (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { if (bit (insn, 25)) switch (bits (insn, 20, 24)) { case 0x10: return arm_copy_unmodified (gdbarch, insn, "movw", dsc); case 0x14: return arm_copy_unmodified (gdbarch, insn, "movt", dsc); case 0x12: case 0x16: return arm_copy_unmodified (gdbarch, insn, "msr imm", dsc); default: return arm_copy_alu_imm (gdbarch, insn, regs, dsc); } else { uint32_t op1 = bits (insn, 20, 24), op2 = bits (insn, 4, 7); if ((op1 & 0x19) != 0x10 && (op2 & 0x1) == 0x0) return arm_copy_alu_reg (gdbarch, insn, regs, dsc); else if ((op1 & 0x19) != 0x10 && (op2 & 0x9) == 0x1) return arm_copy_alu_shifted_reg (gdbarch, insn, regs, dsc); else if ((op1 & 0x19) == 0x10 && (op2 & 0x8) == 0x0) return arm_decode_miscellaneous (gdbarch, insn, regs, dsc); else if ((op1 & 0x19) == 0x10 && (op2 & 0x9) == 0x8) return arm_copy_unmodified (gdbarch, insn, "halfword mul/mla", dsc); else if ((op1 & 0x10) == 0x00 && op2 == 0x9) return arm_copy_unmodified (gdbarch, insn, "mul/mla", dsc); else if ((op1 & 0x10) == 0x10 && op2 == 0x9) return arm_copy_unmodified (gdbarch, insn, "synch", dsc); else if (op2 == 0xb || (op2 & 0xd) == 0xd) /* 2nd arg means "unprivileged". */ return arm_copy_extra_ld_st (gdbarch, insn, (op1 & 0x12) == 0x02, regs, dsc); } /* Should be unreachable. */ return 1; } static int arm_decode_ld_st_word_ubyte (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { int a = bit (insn, 25), b = bit (insn, 4); uint32_t op1 = bits (insn, 20, 24); if ((!a && (op1 & 0x05) == 0x00 && (op1 & 0x17) != 0x02) || (a && (op1 & 0x05) == 0x00 && (op1 & 0x17) != 0x02 && !b)) return arm_copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 0, 4, 0); else if ((!a && (op1 & 0x17) == 0x02) || (a && (op1 & 0x17) == 0x02 && !b)) return arm_copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 0, 4, 1); else if ((!a && (op1 & 0x05) == 0x01 && (op1 & 0x17) != 0x03) || (a && (op1 & 0x05) == 0x01 && (op1 & 0x17) != 0x03 && !b)) return arm_copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 1, 4, 0); else if ((!a && (op1 & 0x17) == 0x03) || (a && (op1 & 0x17) == 0x03 && !b)) return arm_copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 1, 4, 1); else if ((!a && (op1 & 0x05) == 0x04 && (op1 & 0x17) != 0x06) || (a && (op1 & 0x05) == 0x04 && (op1 & 0x17) != 0x06 && !b)) return arm_copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 0, 1, 0); else if ((!a && (op1 & 0x17) == 0x06) || (a && (op1 & 0x17) == 0x06 && !b)) return arm_copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 0, 1, 1); else if ((!a && (op1 & 0x05) == 0x05 && (op1 & 0x17) != 0x07) || (a && (op1 & 0x05) == 0x05 && (op1 & 0x17) != 0x07 && !b)) return arm_copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 1, 1, 0); else if ((!a && (op1 & 0x17) == 0x07) || (a && (op1 & 0x17) == 0x07 && !b)) return arm_copy_ldr_str_ldrb_strb (gdbarch, insn, regs, dsc, 1, 1, 1); /* Should be unreachable. */ return 1; } static int arm_decode_media (struct gdbarch *gdbarch, uint32_t insn, arm_displaced_step_copy_insn_closure *dsc) { switch (bits (insn, 20, 24)) { case 0x00: case 0x01: case 0x02: case 0x03: return arm_copy_unmodified (gdbarch, insn, "parallel add/sub signed", dsc); case 0x04: case 0x05: case 0x06: case 0x07: return arm_copy_unmodified (gdbarch, insn, "parallel add/sub unsigned", dsc); case 0x08: case 0x09: case 0x0a: case 0x0b: case 0x0c: case 0x0d: case 0x0e: case 0x0f: return arm_copy_unmodified (gdbarch, insn, "decode/pack/unpack/saturate/reverse", dsc); case 0x18: if (bits (insn, 5, 7) == 0) /* op2. */ { if (bits (insn, 12, 15) == 0xf) return arm_copy_unmodified (gdbarch, insn, "usad8", dsc); else return arm_copy_unmodified (gdbarch, insn, "usada8", dsc); } else return arm_copy_undef (gdbarch, insn, dsc); case 0x1a: case 0x1b: if (bits (insn, 5, 6) == 0x2) /* op2[1:0]. */ return arm_copy_unmodified (gdbarch, insn, "sbfx", dsc); else return arm_copy_undef (gdbarch, insn, dsc); case 0x1c: case 0x1d: if (bits (insn, 5, 6) == 0x0) /* op2[1:0]. */ { if (bits (insn, 0, 3) == 0xf) return arm_copy_unmodified (gdbarch, insn, "bfc", dsc); else return arm_copy_unmodified (gdbarch, insn, "bfi", dsc); } else return arm_copy_undef (gdbarch, insn, dsc); case 0x1e: case 0x1f: if (bits (insn, 5, 6) == 0x2) /* op2[1:0]. */ return arm_copy_unmodified (gdbarch, insn, "ubfx", dsc); else return arm_copy_undef (gdbarch, insn, dsc); } /* Should be unreachable. */ return 1; } static int arm_decode_b_bl_ldmstm (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { if (bit (insn, 25)) return arm_copy_b_bl_blx (gdbarch, insn, regs, dsc); else return arm_copy_block_xfer (gdbarch, insn, regs, dsc); } static int arm_decode_ext_reg_ld_st (struct gdbarch *gdbarch, uint32_t insn, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { unsigned int opcode = bits (insn, 20, 24); switch (opcode) { case 0x04: case 0x05: /* VFP/Neon mrrc/mcrr. */ return arm_copy_unmodified (gdbarch, insn, "vfp/neon mrrc/mcrr", dsc); case 0x08: case 0x0a: case 0x0c: case 0x0e: case 0x12: case 0x16: return arm_copy_unmodified (gdbarch, insn, "vfp/neon vstm/vpush", dsc); case 0x09: case 0x0b: case 0x0d: case 0x0f: case 0x13: case 0x17: return arm_copy_unmodified (gdbarch, insn, "vfp/neon vldm/vpop", dsc); case 0x10: case 0x14: case 0x18: case 0x1c: /* vstr. */ case 0x11: case 0x15: case 0x19: case 0x1d: /* vldr. */ /* Note: no writeback for these instructions. Bit 25 will always be zero though (via caller), so the following works OK. */ return arm_copy_copro_load_store (gdbarch, insn, regs, dsc); } /* Should be unreachable. */ return 1; } /* Decode shifted register instructions. */ static int thumb2_decode_dp_shift_reg (struct gdbarch *gdbarch, uint16_t insn1, uint16_t insn2, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { /* PC is only allowed to be used in instruction MOV. */ unsigned int op = bits (insn1, 5, 8); unsigned int rn = bits (insn1, 0, 3); if (op == 0x2 && rn == 0xf) /* MOV */ return thumb2_copy_alu_imm (gdbarch, insn1, insn2, regs, dsc); else return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "dp (shift reg)", dsc); } /* Decode extension register load/store. Exactly the same as arm_decode_ext_reg_ld_st. */ static int thumb2_decode_ext_reg_ld_st (struct gdbarch *gdbarch, uint16_t insn1, uint16_t insn2, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { unsigned int opcode = bits (insn1, 4, 8); switch (opcode) { case 0x04: case 0x05: return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "vfp/neon vmov", dsc); case 0x08: case 0x0c: /* 01x00 */ case 0x0a: case 0x0e: /* 01x10 */ case 0x12: case 0x16: /* 10x10 */ return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "vfp/neon vstm/vpush", dsc); case 0x09: case 0x0d: /* 01x01 */ case 0x0b: case 0x0f: /* 01x11 */ case 0x13: case 0x17: /* 10x11 */ return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "vfp/neon vldm/vpop", dsc); case 0x10: case 0x14: case 0x18: case 0x1c: /* vstr. */ return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "vstr", dsc); case 0x11: case 0x15: case 0x19: case 0x1d: /* vldr. */ return thumb2_copy_copro_load_store (gdbarch, insn1, insn2, regs, dsc); } /* Should be unreachable. */ return 1; } static int arm_decode_svc_copro (struct gdbarch *gdbarch, uint32_t insn, regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { unsigned int op1 = bits (insn, 20, 25); int op = bit (insn, 4); unsigned int coproc = bits (insn, 8, 11); if ((op1 & 0x20) == 0x00 && (op1 & 0x3a) != 0x00 && (coproc & 0xe) == 0xa) return arm_decode_ext_reg_ld_st (gdbarch, insn, regs, dsc); else if ((op1 & 0x21) == 0x00 && (op1 & 0x3a) != 0x00 && (coproc & 0xe) != 0xa) /* stc/stc2. */ return arm_copy_copro_load_store (gdbarch, insn, regs, dsc); else if ((op1 & 0x21) == 0x01 && (op1 & 0x3a) != 0x00 && (coproc & 0xe) != 0xa) /* ldc/ldc2 imm/lit. */ return arm_copy_copro_load_store (gdbarch, insn, regs, dsc); else if ((op1 & 0x3e) == 0x00) return arm_copy_undef (gdbarch, insn, dsc); else if ((op1 & 0x3e) == 0x04 && (coproc & 0xe) == 0xa) return arm_copy_unmodified (gdbarch, insn, "neon 64bit xfer", dsc); else if (op1 == 0x04 && (coproc & 0xe) != 0xa) return arm_copy_unmodified (gdbarch, insn, "mcrr/mcrr2", dsc); else if (op1 == 0x05 && (coproc & 0xe) != 0xa) return arm_copy_unmodified (gdbarch, insn, "mrrc/mrrc2", dsc); else if ((op1 & 0x30) == 0x20 && !op) { if ((coproc & 0xe) == 0xa) return arm_copy_unmodified (gdbarch, insn, "vfp dataproc", dsc); else return arm_copy_unmodified (gdbarch, insn, "cdp/cdp2", dsc); } else if ((op1 & 0x30) == 0x20 && op) return arm_copy_unmodified (gdbarch, insn, "neon 8/16/32 bit xfer", dsc); else if ((op1 & 0x31) == 0x20 && op && (coproc & 0xe) != 0xa) return arm_copy_unmodified (gdbarch, insn, "mcr/mcr2", dsc); else if ((op1 & 0x31) == 0x21 && op && (coproc & 0xe) != 0xa) return arm_copy_unmodified (gdbarch, insn, "mrc/mrc2", dsc); else if ((op1 & 0x30) == 0x30) return arm_copy_svc (gdbarch, insn, regs, dsc); else return arm_copy_undef (gdbarch, insn, dsc); /* Possibly unreachable. */ } static int thumb2_decode_svc_copro (struct gdbarch *gdbarch, uint16_t insn1, uint16_t insn2, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { unsigned int coproc = bits (insn2, 8, 11); unsigned int bit_5_8 = bits (insn1, 5, 8); unsigned int bit_9 = bit (insn1, 9); unsigned int bit_4 = bit (insn1, 4); if (bit_9 == 0) { if (bit_5_8 == 2) return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "neon 64bit xfer/mrrc/mrrc2/mcrr/mcrr2", dsc); else if (bit_5_8 == 0) /* UNDEFINED. */ return thumb_32bit_copy_undef (gdbarch, insn1, insn2, dsc); else { /*coproc is 101x. SIMD/VFP, ext registers load/store. */ if ((coproc & 0xe) == 0xa) return thumb2_decode_ext_reg_ld_st (gdbarch, insn1, insn2, regs, dsc); else /* coproc is not 101x. */ { if (bit_4 == 0) /* STC/STC2. */ return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "stc/stc2", dsc); else /* LDC/LDC2 {literal, immediate}. */ return thumb2_copy_copro_load_store (gdbarch, insn1, insn2, regs, dsc); } } } else return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "coproc", dsc); return 0; } static void install_pc_relative (struct gdbarch *gdbarch, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc, int rd) { /* ADR Rd, #imm Rewrite as: Preparation: Rd <- PC Insn: ADD Rd, #imm Cleanup: Null. */ /* Rd <- PC */ int val = displaced_read_reg (regs, dsc, ARM_PC_REGNUM); displaced_write_reg (regs, dsc, rd, val, CANNOT_WRITE_PC); } static int thumb_copy_pc_relative_16bit (struct gdbarch *gdbarch, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc, int rd, unsigned int imm) { /* Encoding T2: ADDS Rd, #imm */ dsc->modinsn[0] = (0x3000 | (rd << 8) | imm); install_pc_relative (gdbarch, regs, dsc, rd); return 0; } static int thumb_decode_pc_relative_16bit (struct gdbarch *gdbarch, uint16_t insn, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { unsigned int rd = bits (insn, 8, 10); unsigned int imm8 = bits (insn, 0, 7); displaced_debug_printf ("copying thumb adr r%d, #%d insn %.4x", rd, imm8, insn); return thumb_copy_pc_relative_16bit (gdbarch, regs, dsc, rd, imm8); } static int thumb_copy_pc_relative_32bit (struct gdbarch *gdbarch, uint16_t insn1, uint16_t insn2, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { unsigned int rd = bits (insn2, 8, 11); /* Since immediate has the same encoding in ADR ADD and SUB, so we simply extract raw immediate encoding rather than computing immediate. When generating ADD or SUB instruction, we can simply perform OR operation to set immediate into ADD. */ unsigned int imm_3_8 = insn2 & 0x70ff; unsigned int imm_i = insn1 & 0x0400; /* Clear all bits except bit 10. */ displaced_debug_printf ("copying thumb adr r%d, #%d:%d insn %.4x%.4x", rd, imm_i, imm_3_8, insn1, insn2); if (bit (insn1, 7)) /* Encoding T2 */ { /* Encoding T3: SUB Rd, Rd, #imm */ dsc->modinsn[0] = (0xf1a0 | rd | imm_i); dsc->modinsn[1] = ((rd << 8) | imm_3_8); } else /* Encoding T3 */ { /* Encoding T3: ADD Rd, Rd, #imm */ dsc->modinsn[0] = (0xf100 | rd | imm_i); dsc->modinsn[1] = ((rd << 8) | imm_3_8); } dsc->numinsns = 2; install_pc_relative (gdbarch, regs, dsc, rd); return 0; } static int thumb_copy_16bit_ldr_literal (struct gdbarch *gdbarch, uint16_t insn1, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { unsigned int rt = bits (insn1, 8, 10); unsigned int pc; int imm8 = (bits (insn1, 0, 7) << 2); /* LDR Rd, #imm8 Rwrite as: Preparation: tmp0 <- R0, tmp2 <- R2, tmp3 <- R3, R2 <- PC, R3 <- #imm8; Insn: LDR R0, [R2, R3]; Cleanup: R2 <- tmp2, R3 <- tmp3, Rd <- R0, R0 <- tmp0 */ displaced_debug_printf ("copying thumb ldr r%d [pc #%d]", rt, imm8); dsc->tmp[0] = displaced_read_reg (regs, dsc, 0); dsc->tmp[2] = displaced_read_reg (regs, dsc, 2); dsc->tmp[3] = displaced_read_reg (regs, dsc, 3); pc = displaced_read_reg (regs, dsc, ARM_PC_REGNUM); /* The assembler calculates the required value of the offset from the Align(PC,4) value of this instruction to the label. */ pc = pc & 0xfffffffc; displaced_write_reg (regs, dsc, 2, pc, CANNOT_WRITE_PC); displaced_write_reg (regs, dsc, 3, imm8, CANNOT_WRITE_PC); dsc->rd = rt; dsc->u.ldst.xfersize = 4; dsc->u.ldst.rn = 0; dsc->u.ldst.immed = 0; dsc->u.ldst.writeback = 0; dsc->u.ldst.restore_r4 = 0; dsc->modinsn[0] = 0x58d0; /* ldr r0, [r2, r3]*/ dsc->cleanup = &cleanup_load; return 0; } /* Copy Thumb cbnz/cbz instruction. */ static int thumb_copy_cbnz_cbz (struct gdbarch *gdbarch, uint16_t insn1, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { int non_zero = bit (insn1, 11); unsigned int imm5 = (bit (insn1, 9) << 6) | (bits (insn1, 3, 7) << 1); CORE_ADDR from = dsc->insn_addr; int rn = bits (insn1, 0, 2); int rn_val = displaced_read_reg (regs, dsc, rn); dsc->u.branch.cond = (rn_val && non_zero) || (!rn_val && !non_zero); /* CBNZ and CBZ do not affect the condition flags. If condition is true, set it INST_AL, so cleanup_branch will know branch is taken, otherwise, condition is false, let it be, cleanup_branch will do nothing. */ if (dsc->u.branch.cond) { dsc->u.branch.cond = INST_AL; dsc->u.branch.dest = from + 4 + imm5; } else dsc->u.branch.dest = from + 2; dsc->u.branch.link = 0; dsc->u.branch.exchange = 0; displaced_debug_printf ("copying %s [r%d = 0x%x] insn %.4x to %.8lx", non_zero ? "cbnz" : "cbz", rn, rn_val, insn1, dsc->u.branch.dest); dsc->modinsn[0] = THUMB_NOP; dsc->cleanup = &cleanup_branch; return 0; } /* Copy Table Branch Byte/Halfword */ static int thumb2_copy_table_branch (struct gdbarch *gdbarch, uint16_t insn1, uint16_t insn2, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { ULONGEST rn_val, rm_val; int is_tbh = bit (insn2, 4); CORE_ADDR halfwords = 0; enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); rn_val = displaced_read_reg (regs, dsc, bits (insn1, 0, 3)); rm_val = displaced_read_reg (regs, dsc, bits (insn2, 0, 3)); if (is_tbh) { gdb_byte buf[2]; target_read_memory (rn_val + 2 * rm_val, buf, 2); halfwords = extract_unsigned_integer (buf, 2, byte_order); } else { gdb_byte buf[1]; target_read_memory (rn_val + rm_val, buf, 1); halfwords = extract_unsigned_integer (buf, 1, byte_order); } displaced_debug_printf ("%s base 0x%x offset 0x%x offset 0x%x", is_tbh ? "tbh" : "tbb", (unsigned int) rn_val, (unsigned int) rm_val, (unsigned int) halfwords); dsc->u.branch.cond = INST_AL; dsc->u.branch.link = 0; dsc->u.branch.exchange = 0; dsc->u.branch.dest = dsc->insn_addr + 4 + 2 * halfwords; dsc->cleanup = &cleanup_branch; return 0; } static void cleanup_pop_pc_16bit_all (struct gdbarch *gdbarch, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { /* PC <- r7 */ int val = displaced_read_reg (regs, dsc, 7); displaced_write_reg (regs, dsc, ARM_PC_REGNUM, val, BX_WRITE_PC); /* r7 <- r8 */ val = displaced_read_reg (regs, dsc, 8); displaced_write_reg (regs, dsc, 7, val, CANNOT_WRITE_PC); /* r8 <- tmp[0] */ displaced_write_reg (regs, dsc, 8, dsc->tmp[0], CANNOT_WRITE_PC); } static int thumb_copy_pop_pc_16bit (struct gdbarch *gdbarch, uint16_t insn1, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { dsc->u.block.regmask = insn1 & 0x00ff; /* Rewrite instruction: POP {rX, rY, ...,rZ, PC} to : (1) register list is full, that is, r0-r7 are used. Prepare: tmp[0] <- r8 POP {r0, r1, ...., r6, r7}; remove PC from reglist MOV r8, r7; Move value of r7 to r8; POP {r7}; Store PC value into r7. Cleanup: PC <- r7, r7 <- r8, r8 <-tmp[0] (2) register list is not full, supposing there are N registers in register list (except PC, 0 <= N <= 7). Prepare: for each i, 0 - N, tmp[i] <- ri. POP {r0, r1, ...., rN}; Cleanup: Set registers in original reglist from r0 - rN. Restore r0 - rN from tmp[] properly. */ displaced_debug_printf ("copying thumb pop {%.8x, pc} insn %.4x", dsc->u.block.regmask, insn1); if (dsc->u.block.regmask == 0xff) { dsc->tmp[0] = displaced_read_reg (regs, dsc, 8); dsc->modinsn[0] = (insn1 & 0xfeff); /* POP {r0,r1,...,r6, r7} */ dsc->modinsn[1] = 0x46b8; /* MOV r8, r7 */ dsc->modinsn[2] = 0xbc80; /* POP {r7} */ dsc->numinsns = 3; dsc->cleanup = &cleanup_pop_pc_16bit_all; } else { unsigned int num_in_list = count_one_bits (dsc->u.block.regmask); unsigned int i; unsigned int new_regmask; for (i = 0; i < num_in_list + 1; i++) dsc->tmp[i] = displaced_read_reg (regs, dsc, i); new_regmask = (1 << (num_in_list + 1)) - 1; displaced_debug_printf ("POP {..., pc}: original reg list %.4x, " "modified list %.4x", (int) dsc->u.block.regmask, new_regmask); dsc->u.block.regmask |= 0x8000; dsc->u.block.writeback = 0; dsc->u.block.cond = INST_AL; dsc->modinsn[0] = (insn1 & ~0x1ff) | (new_regmask & 0xff); dsc->cleanup = &cleanup_block_load_pc; } return 0; } static void thumb_process_displaced_16bit_insn (struct gdbarch *gdbarch, uint16_t insn1, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { unsigned short op_bit_12_15 = bits (insn1, 12, 15); unsigned short op_bit_10_11 = bits (insn1, 10, 11); int err = 0; /* 16-bit thumb instructions. */ switch (op_bit_12_15) { /* Shift (imme), add, subtract, move and compare. */ case 0: case 1: case 2: case 3: err = thumb_copy_unmodified_16bit (gdbarch, insn1, "shift/add/sub/mov/cmp", dsc); break; case 4: switch (op_bit_10_11) { case 0: /* Data-processing */ err = thumb_copy_unmodified_16bit (gdbarch, insn1, "data-processing", dsc); break; case 1: /* Special data instructions and branch and exchange. */ { unsigned short op = bits (insn1, 7, 9); if (op == 6 || op == 7) /* BX or BLX */ err = thumb_copy_bx_blx_reg (gdbarch, insn1, regs, dsc); else if (bits (insn1, 6, 7) != 0) /* ADD/MOV/CMP high registers. */ err = thumb_copy_alu_reg (gdbarch, insn1, regs, dsc); else err = thumb_copy_unmodified_16bit (gdbarch, insn1, "special data", dsc); } break; default: /* LDR (literal) */ err = thumb_copy_16bit_ldr_literal (gdbarch, insn1, regs, dsc); } break; case 5: case 6: case 7: case 8: case 9: /* Load/Store single data item */ err = thumb_copy_unmodified_16bit (gdbarch, insn1, "ldr/str", dsc); break; case 10: if (op_bit_10_11 < 2) /* Generate PC-relative address */ err = thumb_decode_pc_relative_16bit (gdbarch, insn1, regs, dsc); else /* Generate SP-relative address */ err = thumb_copy_unmodified_16bit (gdbarch, insn1, "sp-relative", dsc); break; case 11: /* Misc 16-bit instructions */ { switch (bits (insn1, 8, 11)) { case 1: case 3: case 9: case 11: /* CBNZ, CBZ */ err = thumb_copy_cbnz_cbz (gdbarch, insn1, regs, dsc); break; case 12: case 13: /* POP */ if (bit (insn1, 8)) /* PC is in register list. */ err = thumb_copy_pop_pc_16bit (gdbarch, insn1, regs, dsc); else err = thumb_copy_unmodified_16bit (gdbarch, insn1, "pop", dsc); break; case 15: /* If-Then, and hints */ if (bits (insn1, 0, 3)) /* If-Then makes up to four following instructions conditional. IT instruction itself is not conditional, so handle it as a common unmodified instruction. */ err = thumb_copy_unmodified_16bit (gdbarch, insn1, "If-Then", dsc); else err = thumb_copy_unmodified_16bit (gdbarch, insn1, "hints", dsc); break; default: err = thumb_copy_unmodified_16bit (gdbarch, insn1, "misc", dsc); } } break; case 12: if (op_bit_10_11 < 2) /* Store multiple registers */ err = thumb_copy_unmodified_16bit (gdbarch, insn1, "stm", dsc); else /* Load multiple registers */ err = thumb_copy_unmodified_16bit (gdbarch, insn1, "ldm", dsc); break; case 13: /* Conditional branch and supervisor call */ if (bits (insn1, 9, 11) != 7) /* conditional branch */ err = thumb_copy_b (gdbarch, insn1, dsc); else err = thumb_copy_svc (gdbarch, insn1, regs, dsc); break; case 14: /* Unconditional branch */ err = thumb_copy_b (gdbarch, insn1, dsc); break; default: err = 1; } if (err) internal_error (_("thumb_process_displaced_16bit_insn: Instruction decode error")); } static int decode_thumb_32bit_ld_mem_hints (struct gdbarch *gdbarch, uint16_t insn1, uint16_t insn2, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { int rt = bits (insn2, 12, 15); int rn = bits (insn1, 0, 3); int op1 = bits (insn1, 7, 8); switch (bits (insn1, 5, 6)) { case 0: /* Load byte and memory hints */ if (rt == 0xf) /* PLD/PLI */ { if (rn == 0xf) /* PLD literal or Encoding T3 of PLI(immediate, literal). */ return thumb2_copy_preload (gdbarch, insn1, insn2, regs, dsc); else return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "pli/pld", dsc); } else { if (rn == 0xf) /* LDRB/LDRSB (literal) */ return thumb2_copy_load_literal (gdbarch, insn1, insn2, regs, dsc, 1); else return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "ldrb{reg, immediate}/ldrbt", dsc); } break; case 1: /* Load halfword and memory hints. */ if (rt == 0xf) /* PLD{W} and Unalloc memory hint. */ return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "pld/unalloc memhint", dsc); else { if (rn == 0xf) return thumb2_copy_load_literal (gdbarch, insn1, insn2, regs, dsc, 2); else return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "ldrh/ldrht", dsc); } break; case 2: /* Load word */ { int insn2_bit_8_11 = bits (insn2, 8, 11); if (rn == 0xf) return thumb2_copy_load_literal (gdbarch, insn1, insn2, regs, dsc, 4); else if (op1 == 0x1) /* Encoding T3 */ return thumb2_copy_load_reg_imm (gdbarch, insn1, insn2, regs, dsc, 0, 1); else /* op1 == 0x0 */ { if (insn2_bit_8_11 == 0xc || (insn2_bit_8_11 & 0x9) == 0x9) /* LDR (immediate) */ return thumb2_copy_load_reg_imm (gdbarch, insn1, insn2, regs, dsc, bit (insn2, 8), 1); else if (insn2_bit_8_11 == 0xe) /* LDRT */ return thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "ldrt", dsc); else /* LDR (register) */ return thumb2_copy_load_reg_imm (gdbarch, insn1, insn2, regs, dsc, 0, 0); } break; } default: return thumb_32bit_copy_undef (gdbarch, insn1, insn2, dsc); break; } return 0; } static void thumb_process_displaced_32bit_insn (struct gdbarch *gdbarch, uint16_t insn1, uint16_t insn2, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { int err = 0; unsigned short op = bit (insn2, 15); unsigned int op1 = bits (insn1, 11, 12); switch (op1) { case 1: { switch (bits (insn1, 9, 10)) { case 0: if (bit (insn1, 6)) { /* Load/store {dual, exclusive}, table branch. */ if (bits (insn1, 7, 8) == 1 && bits (insn1, 4, 5) == 1 && bits (insn2, 5, 7) == 0) err = thumb2_copy_table_branch (gdbarch, insn1, insn2, regs, dsc); else /* PC is not allowed to use in load/store {dual, exclusive} instructions. */ err = thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "load/store dual/ex", dsc); } else /* load/store multiple */ { switch (bits (insn1, 7, 8)) { case 0: case 3: /* SRS, RFE */ err = thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "srs/rfe", dsc); break; case 1: case 2: /* LDM/STM/PUSH/POP */ err = thumb2_copy_block_xfer (gdbarch, insn1, insn2, regs, dsc); break; } } break; case 1: /* Data-processing (shift register). */ err = thumb2_decode_dp_shift_reg (gdbarch, insn1, insn2, regs, dsc); break; default: /* Coprocessor instructions. */ err = thumb2_decode_svc_copro (gdbarch, insn1, insn2, regs, dsc); break; } break; } case 2: /* op1 = 2 */ if (op) /* Branch and misc control. */ { if (bit (insn2, 14) /* BLX/BL */ || bit (insn2, 12) /* Unconditional branch */ || (bits (insn1, 7, 9) != 0x7)) /* Conditional branch */ err = thumb2_copy_b_bl_blx (gdbarch, insn1, insn2, regs, dsc); else err = thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "misc ctrl", dsc); } else { if (bit (insn1, 9)) /* Data processing (plain binary imm). */ { int dp_op = bits (insn1, 4, 8); int rn = bits (insn1, 0, 3); if ((dp_op == 0 || dp_op == 0xa) && rn == 0xf) err = thumb_copy_pc_relative_32bit (gdbarch, insn1, insn2, regs, dsc); else err = thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "dp/pb", dsc); } else /* Data processing (modified immediate) */ err = thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "dp/mi", dsc); } break; case 3: /* op1 = 3 */ switch (bits (insn1, 9, 10)) { case 0: if (bit (insn1, 4)) err = decode_thumb_32bit_ld_mem_hints (gdbarch, insn1, insn2, regs, dsc); else /* NEON Load/Store and Store single data item */ err = thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "neon elt/struct load/store", dsc); break; case 1: /* op1 = 3, bits (9, 10) == 1 */ switch (bits (insn1, 7, 8)) { case 0: case 1: /* Data processing (register) */ err = thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "dp(reg)", dsc); break; case 2: /* Multiply and absolute difference */ err = thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "mul/mua/diff", dsc); break; case 3: /* Long multiply and divide */ err = thumb_copy_unmodified_32bit (gdbarch, insn1, insn2, "lmul/lmua", dsc); break; } break; default: /* Coprocessor instructions */ err = thumb2_decode_svc_copro (gdbarch, insn1, insn2, regs, dsc); break; } break; default: err = 1; } if (err) internal_error (_("thumb_process_displaced_32bit_insn: Instruction decode error")); } static void thumb_process_displaced_insn (struct gdbarch *gdbarch, CORE_ADDR from, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch); uint16_t insn1 = read_memory_unsigned_integer (from, 2, byte_order_for_code); displaced_debug_printf ("process thumb insn %.4x at %.8lx", insn1, (unsigned long) from); dsc->is_thumb = 1; dsc->insn_size = thumb_insn_size (insn1); if (thumb_insn_size (insn1) == 4) { uint16_t insn2 = read_memory_unsigned_integer (from + 2, 2, byte_order_for_code); thumb_process_displaced_32bit_insn (gdbarch, insn1, insn2, regs, dsc); } else thumb_process_displaced_16bit_insn (gdbarch, insn1, regs, dsc); } void arm_process_displaced_insn (struct gdbarch *gdbarch, CORE_ADDR from, CORE_ADDR to, struct regcache *regs, arm_displaced_step_copy_insn_closure *dsc) { int err = 0; enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch); uint32_t insn; /* Most displaced instructions use a 1-instruction scratch space, so set this here and override below if/when necessary. */ dsc->numinsns = 1; dsc->insn_addr = from; dsc->scratch_base = to; dsc->cleanup = NULL; dsc->wrote_to_pc = 0; if (!displaced_in_arm_mode (regs)) return thumb_process_displaced_insn (gdbarch, from, regs, dsc); dsc->is_thumb = 0; dsc->insn_size = 4; insn = read_memory_unsigned_integer (from, 4, byte_order_for_code); displaced_debug_printf ("stepping insn %.8lx at %.8lx", (unsigned long) insn, (unsigned long) from); if ((insn & 0xf0000000) == 0xf0000000) err = arm_decode_unconditional (gdbarch, insn, regs, dsc); else switch (((insn & 0x10) >> 4) | ((insn & 0xe000000) >> 24)) { case 0x0: case 0x1: case 0x2: case 0x3: err = arm_decode_dp_misc (gdbarch, insn, regs, dsc); break; case 0x4: case 0x5: case 0x6: err = arm_decode_ld_st_word_ubyte (gdbarch, insn, regs, dsc); break; case 0x7: err = arm_decode_media (gdbarch, insn, dsc); break; case 0x8: case 0x9: case 0xa: case 0xb: err = arm_decode_b_bl_ldmstm (gdbarch, insn, regs, dsc); break; case 0xc: case 0xd: case 0xe: case 0xf: err = arm_decode_svc_copro (gdbarch, insn, regs, dsc); break; } if (err) internal_error (_("arm_process_displaced_insn: Instruction decode error")); } /* Actually set up the scratch space for a displaced instruction. */ void arm_displaced_init_closure (struct gdbarch *gdbarch, CORE_ADDR from, CORE_ADDR to, arm_displaced_step_copy_insn_closure *dsc) { arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); unsigned int i, len, offset; enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch); int size = dsc->is_thumb? 2 : 4; const gdb_byte *bkp_insn; offset = 0; /* Poke modified instruction(s). */ for (i = 0; i < dsc->numinsns; i++) { if (size == 4) displaced_debug_printf ("writing insn %.8lx at %.8lx", dsc->modinsn[i], (unsigned long) to + offset); else if (size == 2) displaced_debug_printf ("writing insn %.4x at %.8lx", (unsigned short) dsc->modinsn[i], (unsigned long) to + offset); write_memory_unsigned_integer (to + offset, size, byte_order_for_code, dsc->modinsn[i]); offset += size; } /* Choose the correct breakpoint instruction. */ if (dsc->is_thumb) { bkp_insn = tdep->thumb_breakpoint; len = tdep->thumb_breakpoint_size; } else { bkp_insn = tdep->arm_breakpoint; len = tdep->arm_breakpoint_size; } /* Put breakpoint afterwards. */ write_memory (to + offset, bkp_insn, len); displaced_debug_printf ("copy %s->%s", paddress (gdbarch, from), paddress (gdbarch, to)); } /* Entry point for cleaning things up after a displaced instruction has been single-stepped. */ void arm_displaced_step_fixup (struct gdbarch *gdbarch, struct displaced_step_copy_insn_closure *dsc_, CORE_ADDR from, CORE_ADDR to, struct regcache *regs, bool completed_p) { /* The following block exists as a temporary measure while displaced stepping is fixed architecture at a time within GDB. In an earlier implementation of displaced stepping, if GDB thought the displaced instruction had not been executed then this fix up function was never called. As a consequence, things that should be fixed by this function were left in an unfixed state. However, it's not as simple as always calling this function; this function needs to be updated to decide what should be fixed up based on whether the displaced step executed or not, which requires each architecture to be considered individually. Until this architecture is updated, this block replicates the old behaviour; we just restore the program counter register, and leave everything else unfixed. */ if (!completed_p) { CORE_ADDR pc = regcache_read_pc (regs); pc = from + (pc - to); regcache_write_pc (regs, pc); return; } arm_displaced_step_copy_insn_closure *dsc = (arm_displaced_step_copy_insn_closure *) dsc_; if (dsc->cleanup) dsc->cleanup (gdbarch, regs, dsc); if (!dsc->wrote_to_pc) regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, dsc->insn_addr + dsc->insn_size); } #include "bfd-in2.h" #include "libcoff.h" static int gdb_print_insn_arm (bfd_vma memaddr, disassemble_info *info) { gdb_disassemble_info *di = static_cast (info->application_data); struct gdbarch *gdbarch = di->arch (); if (arm_pc_is_thumb (gdbarch, memaddr)) { static asymbol *asym; static combined_entry_type ce; static struct coff_symbol_struct csym; static struct bfd fake_bfd; static bfd_target fake_target; if (csym.native == NULL) { /* Create a fake symbol vector containing a Thumb symbol. This is solely so that the code in print_insn_little_arm() and print_insn_big_arm() in opcodes/arm-dis.c will detect the presence of a Thumb symbol and switch to decoding Thumb instructions. */ fake_target.flavour = bfd_target_coff_flavour; fake_bfd.xvec = &fake_target; ce.u.syment.n_sclass = C_THUMBEXTFUNC; csym.native = &ce; csym.symbol.the_bfd = &fake_bfd; csym.symbol.name = "fake"; asym = (asymbol *) & csym; } memaddr = UNMAKE_THUMB_ADDR (memaddr); info->symbols = &asym; } else info->symbols = NULL; /* GDB is able to get bfd_mach from the exe_bfd, info->mach is accurate, so mark USER_SPECIFIED_MACHINE_TYPE bit. Otherwise, opcodes/arm-dis.c:print_insn reset info->mach, and it will trigger the assert on the mismatch of info->mach and bfd_get_mach (current_program_space->exec_bfd ()) in default_print_insn. */ if (current_program_space->exec_bfd () != NULL && (current_program_space->exec_bfd ()->arch_info == gdbarch_bfd_arch_info (gdbarch))) info->flags |= USER_SPECIFIED_MACHINE_TYPE; return default_print_insn (memaddr, info); } /* The following define instruction sequences that will cause ARM cpu's to take an undefined instruction trap. These are used to signal a breakpoint to GDB. The newer ARMv4T cpu's are capable of operating in ARM or Thumb modes. A different instruction is required for each mode. The ARM cpu's can also be big or little endian. Thus four different instructions are needed to support all cases. Note: ARMv4 defines several new instructions that will take the undefined instruction trap. ARM7TDMI is nominally ARMv4T, but does not in fact add the new instructions. The new undefined instructions in ARMv4 are all instructions that had no defined behaviour in earlier chips. There is no guarantee that they will raise an exception, but may be treated as NOP's. In practice, it may only safe to rely on instructions matching: 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 C C C C 0 1 1 x x x x x x x x x x x x x x x x x x x x 1 x x x x Even this may only true if the condition predicate is true. The following use a condition predicate of ALWAYS so it is always TRUE. There are other ways of forcing a breakpoint. GNU/Linux, RISC iX, and NetBSD all use a software interrupt rather than an undefined instruction to force a trap. This can be handled by by the abi-specific code during establishment of the gdbarch vector. */ #define ARM_LE_BREAKPOINT {0xFE,0xDE,0xFF,0xE7} #define ARM_BE_BREAKPOINT {0xE7,0xFF,0xDE,0xFE} #define THUMB_LE_BREAKPOINT {0xbe,0xbe} #define THUMB_BE_BREAKPOINT {0xbe,0xbe} static const gdb_byte arm_default_arm_le_breakpoint[] = ARM_LE_BREAKPOINT; static const gdb_byte arm_default_arm_be_breakpoint[] = ARM_BE_BREAKPOINT; static const gdb_byte arm_default_thumb_le_breakpoint[] = THUMB_LE_BREAKPOINT; static const gdb_byte arm_default_thumb_be_breakpoint[] = THUMB_BE_BREAKPOINT; /* Implement the breakpoint_kind_from_pc gdbarch method. */ static int arm_breakpoint_kind_from_pc (struct gdbarch *gdbarch, CORE_ADDR *pcptr) { arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch); if (arm_pc_is_thumb (gdbarch, *pcptr)) { *pcptr = UNMAKE_THUMB_ADDR (*pcptr); /* If we have a separate 32-bit breakpoint instruction for Thumb-2, check whether we are replacing a 32-bit instruction. */ if (tdep->thumb2_breakpoint != NULL) { gdb_byte buf[2]; if (target_read_memory (*pcptr, buf, 2) == 0) { unsigned short inst1; inst1 = extract_unsigned_integer (buf, 2, byte_order_for_code); if (thumb_insn_size (inst1) == 4) return ARM_BP_KIND_THUMB2; } } return ARM_BP_KIND_THUMB; } else return ARM_BP_KIND_ARM; } /* Implement the sw_breakpoint_from_kind gdbarch method. */ static const gdb_byte * arm_sw_breakpoint_from_kind (struct gdbarch *gdbarch, int kind, int *size) { arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); switch (kind) { case ARM_BP_KIND_ARM: *size = tdep->arm_breakpoint_size; return tdep->arm_breakpoint; case ARM_BP_KIND_THUMB: *size = tdep->thumb_breakpoint_size; return tdep->thumb_breakpoint; case ARM_BP_KIND_THUMB2: *size = tdep->thumb2_breakpoint_size; return tdep->thumb2_breakpoint; default: gdb_assert_not_reached ("unexpected arm breakpoint kind"); } } /* Implement the breakpoint_kind_from_current_state gdbarch method. */ static int arm_breakpoint_kind_from_current_state (struct gdbarch *gdbarch, struct regcache *regcache, CORE_ADDR *pcptr) { gdb_byte buf[4]; /* Check the memory pointed by PC is readable. */ if (target_read_memory (regcache_read_pc (regcache), buf, 4) == 0) { struct arm_get_next_pcs next_pcs_ctx; arm_get_next_pcs_ctor (&next_pcs_ctx, &arm_get_next_pcs_ops, gdbarch_byte_order (gdbarch), gdbarch_byte_order_for_code (gdbarch), 0, regcache); std::vector next_pcs = arm_get_next_pcs (&next_pcs_ctx); /* If MEMADDR is the next instruction of current pc, do the software single step computation, and get the thumb mode by the destination address. */ for (CORE_ADDR pc : next_pcs) { if (UNMAKE_THUMB_ADDR (pc) == *pcptr) { if (IS_THUMB_ADDR (pc)) { *pcptr = MAKE_THUMB_ADDR (*pcptr); return arm_breakpoint_kind_from_pc (gdbarch, pcptr); } else return ARM_BP_KIND_ARM; } } } return arm_breakpoint_kind_from_pc (gdbarch, pcptr); } /* Extract from an array REGBUF containing the (raw) register state a function return value of type TYPE, and copy that, in virtual format, into VALBUF. */ static void arm_extract_return_value (struct type *type, struct regcache *regs, gdb_byte *valbuf) { struct gdbarch *gdbarch = regs->arch (); enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); if (TYPE_CODE_FLT == type->code ()) { switch (tdep->fp_model) { case ARM_FLOAT_FPA: { /* The value is in register F0 in internal format. We need to extract the raw value and then convert it to the desired internal type. */ bfd_byte tmpbuf[ARM_FP_REGISTER_SIZE]; regs->cooked_read (ARM_F0_REGNUM, tmpbuf); target_float_convert (tmpbuf, arm_ext_type (gdbarch), valbuf, type); } break; case ARM_FLOAT_SOFT_FPA: case ARM_FLOAT_SOFT_VFP: /* ARM_FLOAT_VFP can arise if this is a variadic function so not using the VFP ABI code. */ case ARM_FLOAT_VFP: regs->cooked_read (ARM_A1_REGNUM, valbuf); if (type->length () > 4) regs->cooked_read (ARM_A1_REGNUM + 1, valbuf + ARM_INT_REGISTER_SIZE); break; default: internal_error (_("arm_extract_return_value: " "Floating point model not supported")); break; } } else if (type->code () == TYPE_CODE_INT || type->code () == TYPE_CODE_CHAR || type->code () == TYPE_CODE_BOOL || type->code () == TYPE_CODE_PTR || TYPE_IS_REFERENCE (type) || type->code () == TYPE_CODE_ENUM || is_fixed_point_type (type)) { /* If the type is a plain integer, then the access is straight-forward. Otherwise we have to play around a bit more. */ int len = type->length (); int regno = ARM_A1_REGNUM; ULONGEST tmp; while (len > 0) { /* By using store_unsigned_integer we avoid having to do anything special for small big-endian values. */ regcache_cooked_read_unsigned (regs, regno++, &tmp); store_unsigned_integer (valbuf, (len > ARM_INT_REGISTER_SIZE ? ARM_INT_REGISTER_SIZE : len), byte_order, tmp); len -= ARM_INT_REGISTER_SIZE; valbuf += ARM_INT_REGISTER_SIZE; } } else { /* For a structure or union the behaviour is as if the value had been stored to word-aligned memory and then loaded into registers with 32-bit load instruction(s). */ int len = type->length (); int regno = ARM_A1_REGNUM; bfd_byte tmpbuf[ARM_INT_REGISTER_SIZE]; while (len > 0) { regs->cooked_read (regno++, tmpbuf); memcpy (valbuf, tmpbuf, len > ARM_INT_REGISTER_SIZE ? ARM_INT_REGISTER_SIZE : len); len -= ARM_INT_REGISTER_SIZE; valbuf += ARM_INT_REGISTER_SIZE; } } } /* Will a function return an aggregate type in memory or in a register? Return 0 if an aggregate type can be returned in a register, 1 if it must be returned in memory. */ static int arm_return_in_memory (struct gdbarch *gdbarch, struct type *type) { enum type_code code; type = check_typedef (type); /* Simple, non-aggregate types (ie not including vectors and complex) are always returned in a register (or registers). */ code = type->code (); if (TYPE_CODE_STRUCT != code && TYPE_CODE_UNION != code && TYPE_CODE_ARRAY != code && TYPE_CODE_COMPLEX != code) return 0; if (TYPE_HAS_DYNAMIC_LENGTH (type)) return 1; if (TYPE_CODE_ARRAY == code && type->is_vector ()) { /* Vector values should be returned using ARM registers if they are not over 16 bytes. */ return (type->length () > 16); } arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); if (tdep->arm_abi != ARM_ABI_APCS) { /* The AAPCS says all aggregates not larger than a word are returned in a register. */ if (type->length () <= ARM_INT_REGISTER_SIZE && language_pass_by_reference (type).trivially_copyable) return 0; return 1; } else { int nRc; /* All aggregate types that won't fit in a register must be returned in memory. */ if (type->length () > ARM_INT_REGISTER_SIZE || !language_pass_by_reference (type).trivially_copyable) return 1; /* In the ARM ABI, "integer" like aggregate types are returned in registers. For an aggregate type to be integer like, its size must be less than or equal to ARM_INT_REGISTER_SIZE and the offset of each addressable subfield must be zero. Note that bit fields are not addressable, and all addressable subfields of unions always start at offset zero. This function is based on the behaviour of GCC 2.95.1. See: gcc/arm.c: arm_return_in_memory() for details. Note: All versions of GCC before GCC 2.95.2 do not set up the parameters correctly for a function returning the following structure: struct { float f;}; This should be returned in memory, not a register. Richard Earnshaw sent me a patch, but I do not know of any way to detect if a function like the above has been compiled with the correct calling convention. */ /* Assume all other aggregate types can be returned in a register. Run a check for structures, unions and arrays. */ nRc = 0; if ((TYPE_CODE_STRUCT == code) || (TYPE_CODE_UNION == code)) { int i; /* Need to check if this struct/union is "integer" like. For this to be true, its size must be less than or equal to ARM_INT_REGISTER_SIZE and the offset of each addressable subfield must be zero. Note that bit fields are not addressable, and unions always start at offset zero. If any of the subfields is a floating point type, the struct/union cannot be an integer type. */ /* For each field in the object, check: 1) Is it FP? --> yes, nRc = 1; 2) Is it addressable (bitpos != 0) and not packed (bitsize == 0)? --> yes, nRc = 1 */ for (i = 0; i < type->num_fields (); i++) { enum type_code field_type_code; field_type_code = check_typedef (type->field (i).type ())->code (); /* Is it a floating point type field? */ if (field_type_code == TYPE_CODE_FLT) { nRc = 1; break; } /* If bitpos != 0, then we have to care about it. */ if (type->field (i).loc_bitpos () != 0) { /* Bitfields are not addressable. If the field bitsize is zero, then the field is not packed. Hence it cannot be a bitfield or any other packed type. */ if (TYPE_FIELD_BITSIZE (type, i) == 0) { nRc = 1; break; } } } } return nRc; } } /* Write into appropriate registers a function return value of type TYPE, given in virtual format. */ static void arm_store_return_value (struct type *type, struct regcache *regs, const gdb_byte *valbuf) { struct gdbarch *gdbarch = regs->arch (); enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); if (type->code () == TYPE_CODE_FLT) { gdb_byte buf[ARM_FP_REGISTER_SIZE]; arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); switch (tdep->fp_model) { case ARM_FLOAT_FPA: target_float_convert (valbuf, type, buf, arm_ext_type (gdbarch)); regs->cooked_write (ARM_F0_REGNUM, buf); break; case ARM_FLOAT_SOFT_FPA: case ARM_FLOAT_SOFT_VFP: /* ARM_FLOAT_VFP can arise if this is a variadic function so not using the VFP ABI code. */ case ARM_FLOAT_VFP: regs->cooked_write (ARM_A1_REGNUM, valbuf); if (type->length () > 4) regs->cooked_write (ARM_A1_REGNUM + 1, valbuf + ARM_INT_REGISTER_SIZE); break; default: internal_error (_("arm_store_return_value: Floating " "point model not supported")); break; } } else if (type->code () == TYPE_CODE_INT || type->code () == TYPE_CODE_CHAR || type->code () == TYPE_CODE_BOOL || type->code () == TYPE_CODE_PTR || TYPE_IS_REFERENCE (type) || type->code () == TYPE_CODE_ENUM) { if (type->length () <= 4) { /* Values of one word or less are zero/sign-extended and returned in r0. */ bfd_byte tmpbuf[ARM_INT_REGISTER_SIZE]; LONGEST val = unpack_long (type, valbuf); store_signed_integer (tmpbuf, ARM_INT_REGISTER_SIZE, byte_order, val); regs->cooked_write (ARM_A1_REGNUM, tmpbuf); } else { /* Integral values greater than one word are stored in consecutive registers starting with r0. This will always be a multiple of the regiser size. */ int len = type->length (); int regno = ARM_A1_REGNUM; while (len > 0) { regs->cooked_write (regno++, valbuf); len -= ARM_INT_REGISTER_SIZE; valbuf += ARM_INT_REGISTER_SIZE; } } } else { /* For a structure or union the behaviour is as if the value had been stored to word-aligned memory and then loaded into registers with 32-bit load instruction(s). */ int len = type->length (); int regno = ARM_A1_REGNUM; bfd_byte tmpbuf[ARM_INT_REGISTER_SIZE]; while (len > 0) { memcpy (tmpbuf, valbuf, len > ARM_INT_REGISTER_SIZE ? ARM_INT_REGISTER_SIZE : len); regs->cooked_write (regno++, tmpbuf); len -= ARM_INT_REGISTER_SIZE; valbuf += ARM_INT_REGISTER_SIZE; } } } /* Handle function return values. */ static enum return_value_convention arm_return_value (struct gdbarch *gdbarch, struct value *function, struct type *valtype, struct regcache *regcache, struct value **read_value, const gdb_byte *writebuf) { arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); struct type *func_type = function ? function->type () : NULL; enum arm_vfp_cprc_base_type vfp_base_type; int vfp_base_count; if (arm_vfp_abi_for_function (gdbarch, func_type) && arm_vfp_call_candidate (valtype, &vfp_base_type, &vfp_base_count)) { int reg_char = arm_vfp_cprc_reg_char (vfp_base_type); int unit_length = arm_vfp_cprc_unit_length (vfp_base_type); int i; gdb_byte *readbuf = nullptr; if (read_value != nullptr) { *read_value = value::allocate (valtype); readbuf = (*read_value)->contents_raw ().data (); } for (i = 0; i < vfp_base_count; i++) { if (reg_char == 'q') { if (writebuf) arm_neon_quad_write (gdbarch, regcache, i, writebuf + i * unit_length); if (readbuf) arm_neon_quad_read (gdbarch, regcache, i, readbuf + i * unit_length); } else { char name_buf[4]; int regnum; xsnprintf (name_buf, sizeof (name_buf), "%c%d", reg_char, i); regnum = user_reg_map_name_to_regnum (gdbarch, name_buf, strlen (name_buf)); if (writebuf) regcache->cooked_write (regnum, writebuf + i * unit_length); if (readbuf) regcache->cooked_read (regnum, readbuf + i * unit_length); } } return RETURN_VALUE_REGISTER_CONVENTION; } if (valtype->code () == TYPE_CODE_STRUCT || valtype->code () == TYPE_CODE_UNION || valtype->code () == TYPE_CODE_ARRAY) { /* From the AAPCS document: Result return: A Composite Type larger than 4 bytes, or whose size cannot be determined statically by both caller and callee, is stored in memory at an address passed as an extra argument when the function was called (Parameter Passing, rule A.4). The memory to be used for the result may be modified at any point during the function call. Parameter Passing: A.4: If the subroutine is a function that returns a result in memory, then the address for the result is placed in r0 and the NCRN is set to r1. */ if (tdep->struct_return == pcc_struct_return || arm_return_in_memory (gdbarch, valtype)) { if (read_value != nullptr) { CORE_ADDR addr; regcache->cooked_read (ARM_A1_REGNUM, &addr); *read_value = value_at_non_lval (valtype, addr); } return RETURN_VALUE_ABI_RETURNS_ADDRESS; } } else if (valtype->code () == TYPE_CODE_COMPLEX) { if (arm_return_in_memory (gdbarch, valtype)) return RETURN_VALUE_STRUCT_CONVENTION; } if (writebuf) arm_store_return_value (valtype, regcache, writebuf); if (read_value != nullptr) { *read_value = value::allocate (valtype); gdb_byte *readbuf = (*read_value)->contents_raw ().data (); arm_extract_return_value (valtype, regcache, readbuf); } return RETURN_VALUE_REGISTER_CONVENTION; } static int arm_get_longjmp_target (frame_info_ptr frame, CORE_ADDR *pc) { struct gdbarch *gdbarch = get_frame_arch (frame); arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); CORE_ADDR jb_addr; gdb_byte buf[ARM_INT_REGISTER_SIZE]; jb_addr = get_frame_register_unsigned (frame, ARM_A1_REGNUM); if (target_read_memory (jb_addr + tdep->jb_pc * tdep->jb_elt_size, buf, ARM_INT_REGISTER_SIZE)) return 0; *pc = extract_unsigned_integer (buf, ARM_INT_REGISTER_SIZE, byte_order); return 1; } /* A call to cmse secure entry function "foo" at "a" is modified by GNU ld as "b". a) bl xxxx xxxx: b) bl yyyy <__acle_se_foo> section .gnu.sgstubs: yyyy: sg // secure gateway b.w xxxx <__acle_se_foo> // original_branch_dest <__acle_se_foo> xxxx: When the control at "b", the pc contains "yyyy" (sg address) which is a trampoline and does not exist in source code. This function returns the target pc "xxxx". For more details please refer to section 5.4 (Entry functions) and section 3.4.4 (C level development flow of secure code) of "armv8-m-security-extensions-requirements-on-development-tools-engineering-specification" document on www.developer.arm.com. */ static CORE_ADDR arm_skip_cmse_entry (CORE_ADDR pc, const char *name, struct objfile *objfile) { int target_len = strlen (name) + strlen ("__acle_se_") + 1; char *target_name = (char *) alloca (target_len); xsnprintf (target_name, target_len, "%s%s", "__acle_se_", name); struct bound_minimal_symbol minsym = lookup_minimal_symbol (target_name, NULL, objfile); if (minsym.minsym != nullptr) return minsym.value_address (); return 0; } /* Return true when SEC points to ".gnu.sgstubs" section. */ static bool arm_is_sgstubs_section (struct obj_section *sec) { return (sec != nullptr && sec->the_bfd_section != nullptr && sec->the_bfd_section->name != nullptr && streq (sec->the_bfd_section->name, ".gnu.sgstubs")); } /* Recognize GCC and GNU ld's trampolines. If we are in a trampoline, return the target PC. Otherwise return 0. */ CORE_ADDR arm_skip_stub (frame_info_ptr frame, CORE_ADDR pc) { const char *name; int namelen; CORE_ADDR start_addr; /* Find the starting address and name of the function containing the PC. */ if (find_pc_partial_function (pc, &name, &start_addr, NULL) == 0) { /* Trampoline 'bx reg' doesn't belong to any functions. Do the check here. */ start_addr = arm_skip_bx_reg (frame, pc); if (start_addr != 0) return start_addr; return 0; } /* If PC is in a Thumb call or return stub, return the address of the target PC, which is in a register. The thunk functions are called _call_via_xx, where x is the register name. The possible names are r0-r9, sl, fp, ip, sp, and lr. ARM RealView has similar functions, named __ARM_call_via_r[0-7]. */ if (startswith (name, "_call_via_") || startswith (name, "__ARM_call_via_")) { /* Use the name suffix to determine which register contains the target PC. */ static const char *table[15] = {"r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "sl", "fp", "ip", "sp", "lr" }; int regno; int offset = strlen (name) - 2; for (regno = 0; regno <= 14; regno++) if (strcmp (&name[offset], table[regno]) == 0) return get_frame_register_unsigned (frame, regno); } /* GNU ld generates __foo_from_arm or __foo_from_thumb for non-interworking calls to foo. We could decode the stubs to find the target but it's easier to use the symbol table. */ namelen = strlen (name); if (name[0] == '_' && name[1] == '_' && ((namelen > 2 + strlen ("_from_thumb") && startswith (name + namelen - strlen ("_from_thumb"), "_from_thumb")) || (namelen > 2 + strlen ("_from_arm") && startswith (name + namelen - strlen ("_from_arm"), "_from_arm")))) { char *target_name; int target_len = namelen - 2; struct bound_minimal_symbol minsym; struct objfile *objfile; struct obj_section *sec; if (name[namelen - 1] == 'b') target_len -= strlen ("_from_thumb"); else target_len -= strlen ("_from_arm"); target_name = (char *) alloca (target_len + 1); memcpy (target_name, name + 2, target_len); target_name[target_len] = '\0'; sec = find_pc_section (pc); objfile = (sec == NULL) ? NULL : sec->objfile; minsym = lookup_minimal_symbol (target_name, NULL, objfile); if (minsym.minsym != NULL) return minsym.value_address (); else return 0; } struct obj_section *section = find_pc_section (pc); /* Check whether SECTION points to the ".gnu.sgstubs" section. */ if (arm_is_sgstubs_section (section)) return arm_skip_cmse_entry (pc, name, section->objfile); return 0; /* not a stub */ } static void arm_update_current_architecture (void) { /* If the current architecture is not ARM, we have nothing to do. */ if (gdbarch_bfd_arch_info (target_gdbarch ())->arch != bfd_arch_arm) return; /* Update the architecture. */ gdbarch_info info; if (!gdbarch_update_p (info)) internal_error (_("could not update architecture")); } static void set_fp_model_sfunc (const char *args, int from_tty, struct cmd_list_element *c) { int fp_model; for (fp_model = ARM_FLOAT_AUTO; fp_model != ARM_FLOAT_LAST; fp_model++) if (strcmp (current_fp_model, fp_model_strings[fp_model]) == 0) { arm_fp_model = (enum arm_float_model) fp_model; break; } if (fp_model == ARM_FLOAT_LAST) internal_error (_("Invalid fp model accepted: %s."), current_fp_model); arm_update_current_architecture (); } static void show_fp_model (struct ui_file *file, int from_tty, struct cmd_list_element *c, const char *value) { if (arm_fp_model == ARM_FLOAT_AUTO && gdbarch_bfd_arch_info (target_gdbarch ())->arch == bfd_arch_arm) { arm_gdbarch_tdep *tdep = gdbarch_tdep (target_gdbarch ()); gdb_printf (file, _("\ The current ARM floating point model is \"auto\" (currently \"%s\").\n"), fp_model_strings[tdep->fp_model]); } else gdb_printf (file, _("\ The current ARM floating point model is \"%s\".\n"), fp_model_strings[arm_fp_model]); } static void arm_set_abi (const char *args, int from_tty, struct cmd_list_element *c) { int arm_abi; for (arm_abi = ARM_ABI_AUTO; arm_abi != ARM_ABI_LAST; arm_abi++) if (strcmp (arm_abi_string, arm_abi_strings[arm_abi]) == 0) { arm_abi_global = (enum arm_abi_kind) arm_abi; break; } if (arm_abi == ARM_ABI_LAST) internal_error (_("Invalid ABI accepted: %s."), arm_abi_string); arm_update_current_architecture (); } static void arm_show_abi (struct ui_file *file, int from_tty, struct cmd_list_element *c, const char *value) { if (arm_abi_global == ARM_ABI_AUTO && gdbarch_bfd_arch_info (target_gdbarch ())->arch == bfd_arch_arm) { arm_gdbarch_tdep *tdep = gdbarch_tdep (target_gdbarch ()); gdb_printf (file, _("\ The current ARM ABI is \"auto\" (currently \"%s\").\n"), arm_abi_strings[tdep->arm_abi]); } else gdb_printf (file, _("The current ARM ABI is \"%s\".\n"), arm_abi_string); } static void arm_show_fallback_mode (struct ui_file *file, int from_tty, struct cmd_list_element *c, const char *value) { gdb_printf (file, _("The current execution mode assumed " "(when symbols are unavailable) is \"%s\".\n"), arm_fallback_mode_string); } static void arm_show_force_mode (struct ui_file *file, int from_tty, struct cmd_list_element *c, const char *value) { gdb_printf (file, _("The current execution mode assumed " "(even when symbols are available) is \"%s\".\n"), arm_force_mode_string); } static void arm_show_unwind_secure_frames (struct ui_file *file, int from_tty, struct cmd_list_element *c, const char *value) { gdb_printf (file, _("Usage of non-secure to secure exception stack unwinding is %s.\n"), arm_unwind_secure_frames ? "on" : "off"); } /* If the user changes the register disassembly style used for info register and other commands, we have to also switch the style used in opcodes for disassembly output. This function is run in the "set arm disassembly" command, and does that. */ static void set_disassembly_style_sfunc (const char *args, int from_tty, struct cmd_list_element *c) { /* Convert the short style name into the long style name (eg, reg-names-*) before calling the generic set_disassembler_options() function. */ std::string long_name = std::string ("reg-names-") + disassembly_style; set_disassembler_options (&long_name[0]); } static void show_disassembly_style_sfunc (struct ui_file *file, int from_tty, struct cmd_list_element *c, const char *value) { struct gdbarch *gdbarch = get_current_arch (); char *options = get_disassembler_options (gdbarch); const char *style = ""; int len = 0; const char *opt; FOR_EACH_DISASSEMBLER_OPTION (opt, options) if (startswith (opt, "reg-names-")) { style = &opt[strlen ("reg-names-")]; len = strcspn (style, ","); } gdb_printf (file, "The disassembly style is \"%.*s\".\n", len, style); } /* Return the ARM register name corresponding to register I. */ static const char * arm_register_name (struct gdbarch *gdbarch, int i) { arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); if (is_s_pseudo (gdbarch, i)) { static const char *const s_pseudo_names[] = { "s0", "s1", "s2", "s3", "s4", "s5", "s6", "s7", "s8", "s9", "s10", "s11", "s12", "s13", "s14", "s15", "s16", "s17", "s18", "s19", "s20", "s21", "s22", "s23", "s24", "s25", "s26", "s27", "s28", "s29", "s30", "s31", }; return s_pseudo_names[i - tdep->s_pseudo_base]; } if (is_q_pseudo (gdbarch, i)) { static const char *const q_pseudo_names[] = { "q0", "q1", "q2", "q3", "q4", "q5", "q6", "q7", "q8", "q9", "q10", "q11", "q12", "q13", "q14", "q15", }; return q_pseudo_names[i - tdep->q_pseudo_base]; } if (is_mve_pseudo (gdbarch, i)) return "p0"; /* RA_AUTH_CODE is used for unwinding only. Do not assign it a name. */ if (is_pacbti_pseudo (gdbarch, i)) return ""; if (i >= ARRAY_SIZE (arm_register_names)) /* These registers are only supported on targets which supply an XML description. */ return ""; /* Non-pseudo registers. */ return arm_register_names[i]; } /* Test whether the coff symbol specific value corresponds to a Thumb function. */ static int coff_sym_is_thumb (int val) { return (val == C_THUMBEXT || val == C_THUMBSTAT || val == C_THUMBEXTFUNC || val == C_THUMBSTATFUNC || val == C_THUMBLABEL); } /* arm_coff_make_msymbol_special() arm_elf_make_msymbol_special() These functions test whether the COFF or ELF symbol corresponds to an address in thumb code, and set a "special" bit in a minimal symbol to indicate that it does. */ static void arm_elf_make_msymbol_special(asymbol *sym, struct minimal_symbol *msym) { elf_symbol_type *elfsym = (elf_symbol_type *) sym; if (ARM_GET_SYM_BRANCH_TYPE (elfsym->internal_elf_sym.st_target_internal) == ST_BRANCH_TO_THUMB) MSYMBOL_SET_SPECIAL (msym); } static void arm_coff_make_msymbol_special(int val, struct minimal_symbol *msym) { if (coff_sym_is_thumb (val)) MSYMBOL_SET_SPECIAL (msym); } static void arm_record_special_symbol (struct gdbarch *gdbarch, struct objfile *objfile, asymbol *sym) { const char *name = bfd_asymbol_name (sym); struct arm_per_bfd *data; struct arm_mapping_symbol new_map_sym; gdb_assert (name[0] == '$'); if (name[1] != 'a' && name[1] != 't' && name[1] != 'd') return; data = arm_bfd_data_key.get (objfile->obfd.get ()); if (data == NULL) data = arm_bfd_data_key.emplace (objfile->obfd.get (), objfile->obfd->section_count); arm_mapping_symbol_vec &map = data->section_maps[bfd_asymbol_section (sym)->index]; new_map_sym.value = sym->value; new_map_sym.type = name[1]; /* Insert at the end, the vector will be sorted on first use. */ map.push_back (new_map_sym); } static void arm_write_pc (struct regcache *regcache, CORE_ADDR pc) { struct gdbarch *gdbarch = regcache->arch (); regcache_cooked_write_unsigned (regcache, ARM_PC_REGNUM, pc); /* If necessary, set the T bit. */ if (arm_apcs_32) { ULONGEST val, t_bit; regcache_cooked_read_unsigned (regcache, ARM_PS_REGNUM, &val); t_bit = arm_psr_thumb_bit (gdbarch); if (arm_pc_is_thumb (gdbarch, pc)) regcache_cooked_write_unsigned (regcache, ARM_PS_REGNUM, val | t_bit); else regcache_cooked_write_unsigned (regcache, ARM_PS_REGNUM, val & ~t_bit); } } /* Read the contents of a NEON quad register, by reading from two double registers. This is used to implement the quad pseudo registers, and for argument passing in case the quad registers are missing; vectors are passed in quad registers when using the VFP ABI, even if a NEON unit is not present. REGNUM is the index of the quad register, in [0, 15]. */ static enum register_status arm_neon_quad_read (struct gdbarch *gdbarch, readable_regcache *regcache, int regnum, gdb_byte *buf) { char name_buf[4]; gdb_byte reg_buf[8]; int offset, double_regnum; enum register_status status; xsnprintf (name_buf, sizeof (name_buf), "d%d", regnum << 1); double_regnum = user_reg_map_name_to_regnum (gdbarch, name_buf, strlen (name_buf)); /* d0 is always the least significant half of q0. */ if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG) offset = 8; else offset = 0; status = regcache->raw_read (double_regnum, reg_buf); if (status != REG_VALID) return status; memcpy (buf + offset, reg_buf, 8); offset = 8 - offset; status = regcache->raw_read (double_regnum + 1, reg_buf); if (status != REG_VALID) return status; memcpy (buf + offset, reg_buf, 8); return REG_VALID; } /* Read the contents of the MVE pseudo register REGNUM and store it in BUF. */ static enum register_status arm_mve_pseudo_read (struct gdbarch *gdbarch, readable_regcache *regcache, int regnum, gdb_byte *buf) { arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); /* P0 is the first 16 bits of VPR. */ return regcache->raw_read_part (tdep->mve_vpr_regnum, 0, 2, buf); } static enum register_status arm_pseudo_read (struct gdbarch *gdbarch, readable_regcache *regcache, int regnum, gdb_byte *buf) { const int num_regs = gdbarch_num_regs (gdbarch); char name_buf[4]; gdb_byte reg_buf[8]; int offset, double_regnum; arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); gdb_assert (regnum >= num_regs); if (is_q_pseudo (gdbarch, regnum)) { /* Quad-precision register. */ return arm_neon_quad_read (gdbarch, regcache, regnum - tdep->q_pseudo_base, buf); } else if (is_mve_pseudo (gdbarch, regnum)) return arm_mve_pseudo_read (gdbarch, regcache, regnum, buf); else { enum register_status status; regnum -= tdep->s_pseudo_base; /* Single-precision register. */ gdb_assert (regnum < 32); /* s0 is always the least significant half of d0. */ if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG) offset = (regnum & 1) ? 0 : 4; else offset = (regnum & 1) ? 4 : 0; xsnprintf (name_buf, sizeof (name_buf), "d%d", regnum >> 1); double_regnum = user_reg_map_name_to_regnum (gdbarch, name_buf, strlen (name_buf)); status = regcache->raw_read (double_regnum, reg_buf); if (status == REG_VALID) memcpy (buf, reg_buf + offset, 4); return status; } } /* Store the contents of BUF to a NEON quad register, by writing to two double registers. This is used to implement the quad pseudo registers, and for argument passing in case the quad registers are missing; vectors are passed in quad registers when using the VFP ABI, even if a NEON unit is not present. REGNUM is the index of the quad register, in [0, 15]. */ static void arm_neon_quad_write (struct gdbarch *gdbarch, struct regcache *regcache, int regnum, const gdb_byte *buf) { char name_buf[4]; int offset, double_regnum; xsnprintf (name_buf, sizeof (name_buf), "d%d", regnum << 1); double_regnum = user_reg_map_name_to_regnum (gdbarch, name_buf, strlen (name_buf)); /* d0 is always the least significant half of q0. */ if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG) offset = 8; else offset = 0; regcache->raw_write (double_regnum, buf + offset); offset = 8 - offset; regcache->raw_write (double_regnum + 1, buf + offset); } /* Store the contents of BUF to the MVE pseudo register REGNUM. */ static void arm_mve_pseudo_write (struct gdbarch *gdbarch, struct regcache *regcache, int regnum, const gdb_byte *buf) { arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); /* P0 is the first 16 bits of VPR. */ regcache->raw_write_part (tdep->mve_vpr_regnum, 0, 2, buf); } static void arm_pseudo_write (struct gdbarch *gdbarch, struct regcache *regcache, int regnum, const gdb_byte *buf) { const int num_regs = gdbarch_num_regs (gdbarch); char name_buf[4]; gdb_byte reg_buf[8]; int offset, double_regnum; arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); gdb_assert (regnum >= num_regs); if (is_q_pseudo (gdbarch, regnum)) { /* Quad-precision register. */ arm_neon_quad_write (gdbarch, regcache, regnum - tdep->q_pseudo_base, buf); } else if (is_mve_pseudo (gdbarch, regnum)) arm_mve_pseudo_write (gdbarch, regcache, regnum, buf); else { regnum -= tdep->s_pseudo_base; /* Single-precision register. */ gdb_assert (regnum < 32); /* s0 is always the least significant half of d0. */ if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG) offset = (regnum & 1) ? 0 : 4; else offset = (regnum & 1) ? 4 : 0; xsnprintf (name_buf, sizeof (name_buf), "d%d", regnum >> 1); double_regnum = user_reg_map_name_to_regnum (gdbarch, name_buf, strlen (name_buf)); regcache->raw_read (double_regnum, reg_buf); memcpy (reg_buf + offset, buf, 4); regcache->raw_write (double_regnum, reg_buf); } } static struct value * value_of_arm_user_reg (frame_info_ptr frame, const void *baton) { const int *reg_p = (const int *) baton; return value_of_register (*reg_p, frame); } static enum gdb_osabi arm_elf_osabi_sniffer (bfd *abfd) { unsigned int elfosabi; enum gdb_osabi osabi = GDB_OSABI_UNKNOWN; elfosabi = elf_elfheader (abfd)->e_ident[EI_OSABI]; if (elfosabi == ELFOSABI_ARM) /* GNU tools use this value. Check note sections in this case, as well. */ { for (asection *sect : gdb_bfd_sections (abfd)) generic_elf_osabi_sniff_abi_tag_sections (abfd, sect, &osabi); } /* Anything else will be handled by the generic ELF sniffer. */ return osabi; } static int arm_register_reggroup_p (struct gdbarch *gdbarch, int regnum, const struct reggroup *group) { /* FPS register's type is INT, but belongs to float_reggroup. Beside this, FPS register belongs to save_regroup, restore_reggroup, and all_reggroup, of course. */ if (regnum == ARM_FPS_REGNUM) return (group == float_reggroup || group == save_reggroup || group == restore_reggroup || group == all_reggroup); else return default_register_reggroup_p (gdbarch, regnum, group); } /* For backward-compatibility we allow two 'g' packet lengths with the remote protocol depending on whether FPA registers are supplied. M-profile targets do not have FPA registers, but some stubs already exist in the wild which use a 'g' packet which supplies them albeit with dummy values. The packet format which includes FPA registers should be considered deprecated for M-profile targets. */ static void arm_register_g_packet_guesses (struct gdbarch *gdbarch) { arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); if (tdep->is_m) { const target_desc *tdesc; /* If we know from the executable this is an M-profile target, cater for remote targets whose register set layout is the same as the FPA layout. */ tdesc = arm_read_mprofile_description (ARM_M_TYPE_WITH_FPA); register_remote_g_packet_guess (gdbarch, ARM_CORE_REGS_SIZE + ARM_FP_REGS_SIZE, tdesc); /* The regular M-profile layout. */ tdesc = arm_read_mprofile_description (ARM_M_TYPE_M_PROFILE); register_remote_g_packet_guess (gdbarch, ARM_CORE_REGS_SIZE, tdesc); /* M-profile plus M4F VFP. */ tdesc = arm_read_mprofile_description (ARM_M_TYPE_VFP_D16); register_remote_g_packet_guess (gdbarch, ARM_CORE_REGS_SIZE + ARM_VFP2_REGS_SIZE, tdesc); /* M-profile plus MVE. */ tdesc = arm_read_mprofile_description (ARM_M_TYPE_MVE); register_remote_g_packet_guess (gdbarch, ARM_CORE_REGS_SIZE + ARM_VFP2_REGS_SIZE + ARM_INT_REGISTER_SIZE, tdesc); /* M-profile system (stack pointers). */ tdesc = arm_read_mprofile_description (ARM_M_TYPE_SYSTEM); register_remote_g_packet_guess (gdbarch, 2 * ARM_INT_REGISTER_SIZE, tdesc); } /* Otherwise we don't have a useful guess. */ } /* Implement the code_of_frame_writable gdbarch method. */ static int arm_code_of_frame_writable (struct gdbarch *gdbarch, frame_info_ptr frame) { arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); if (tdep->is_m && get_frame_type (frame) == SIGTRAMP_FRAME) { /* M-profile exception frames return to some magic PCs, where isn't writable at all. */ return 0; } else return 1; } /* Implement gdbarch_gnu_triplet_regexp. If the arch name is arm then allow it to be postfixed by a version (eg armv7hl). */ static const char * arm_gnu_triplet_regexp (struct gdbarch *gdbarch) { if (strcmp (gdbarch_bfd_arch_info (gdbarch)->arch_name, "arm") == 0) return "arm(v[^- ]*)?"; return gdbarch_bfd_arch_info (gdbarch)->arch_name; } /* Implement the "get_pc_address_flags" gdbarch method. */ static std::string arm_get_pc_address_flags (frame_info_ptr frame, CORE_ADDR pc) { if (get_frame_pc_masked (frame)) return "PAC"; return ""; } /* Initialize the current architecture based on INFO. If possible, re-use an architecture from ARCHES, which is a list of architectures already created during this debugging session. Called e.g. at program startup, when reading a core file, and when reading a binary file. */ static struct gdbarch * arm_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) { struct gdbarch_list *best_arch; enum arm_abi_kind arm_abi = arm_abi_global; enum arm_float_model fp_model = arm_fp_model; tdesc_arch_data_up tdesc_data; int i; bool is_m = false; bool have_sec_ext = false; int vfp_register_count = 0; bool have_s_pseudos = false, have_q_pseudos = false; bool have_wmmx_registers = false; bool have_neon = false; bool have_fpa_registers = true; const struct target_desc *tdesc = info.target_desc; bool have_vfp = false; bool have_mve = false; bool have_pacbti = false; int mve_vpr_regnum = -1; int register_count = ARM_NUM_REGS; bool have_m_profile_msp = false; int m_profile_msp_regnum = -1; int m_profile_psp_regnum = -1; int m_profile_msp_ns_regnum = -1; int m_profile_psp_ns_regnum = -1; int m_profile_msp_s_regnum = -1; int m_profile_psp_s_regnum = -1; int tls_regnum = 0; /* If we have an object to base this architecture on, try to determine its ABI. */ if (arm_abi == ARM_ABI_AUTO && info.abfd != NULL) { int ei_osabi, e_flags; switch (bfd_get_flavour (info.abfd)) { case bfd_target_coff_flavour: /* Assume it's an old APCS-style ABI. */ /* XXX WinCE? */ arm_abi = ARM_ABI_APCS; break; case bfd_target_elf_flavour: ei_osabi = elf_elfheader (info.abfd)->e_ident[EI_OSABI]; e_flags = elf_elfheader (info.abfd)->e_flags; if (ei_osabi == ELFOSABI_ARM) { /* GNU tools used to use this value, but do not for EABI objects. There's nowhere to tag an EABI version anyway, so assume APCS. */ arm_abi = ARM_ABI_APCS; } else if (ei_osabi == ELFOSABI_NONE || ei_osabi == ELFOSABI_GNU) { int eabi_ver = EF_ARM_EABI_VERSION (e_flags); switch (eabi_ver) { case EF_ARM_EABI_UNKNOWN: /* Assume GNU tools. */ arm_abi = ARM_ABI_APCS; break; case EF_ARM_EABI_VER4: case EF_ARM_EABI_VER5: arm_abi = ARM_ABI_AAPCS; /* EABI binaries default to VFP float ordering. They may also contain build attributes that can be used to identify if the VFP argument-passing ABI is in use. */ if (fp_model == ARM_FLOAT_AUTO) { #ifdef HAVE_ELF switch (bfd_elf_get_obj_attr_int (info.abfd, OBJ_ATTR_PROC, Tag_ABI_VFP_args)) { case AEABI_VFP_args_base: /* "The user intended FP parameter/result passing to conform to AAPCS, base variant". */ fp_model = ARM_FLOAT_SOFT_VFP; break; case AEABI_VFP_args_vfp: /* "The user intended FP parameter/result passing to conform to AAPCS, VFP variant". */ fp_model = ARM_FLOAT_VFP; break; case AEABI_VFP_args_toolchain: /* "The user intended FP parameter/result passing to conform to tool chain-specific conventions" - we don't know any such conventions, so leave it as "auto". */ break; case AEABI_VFP_args_compatible: /* "Code is compatible with both the base and VFP variants; the user did not permit non-variadic functions to pass FP parameters/results" - leave it as "auto". */ break; default: /* Attribute value not mentioned in the November 2012 ABI, so leave it as "auto". */ break; } #else fp_model = ARM_FLOAT_SOFT_VFP; #endif } break; default: /* Leave it as "auto". */ warning (_("unknown ARM EABI version 0x%x"), eabi_ver); break; } #ifdef HAVE_ELF /* Detect M-profile programs. This only works if the executable file includes build attributes; GCC does copy them to the executable, but e.g. RealView does not. */ int attr_arch = bfd_elf_get_obj_attr_int (info.abfd, OBJ_ATTR_PROC, Tag_CPU_arch); int attr_profile = bfd_elf_get_obj_attr_int (info.abfd, OBJ_ATTR_PROC, Tag_CPU_arch_profile); /* GCC specifies the profile for v6-M; RealView only specifies the profile for architectures starting with V7 (as opposed to architectures with a tag numerically greater than TAG_CPU_ARCH_V7). */ if (!tdesc_has_registers (tdesc) && (attr_arch == TAG_CPU_ARCH_V6_M || attr_arch == TAG_CPU_ARCH_V6S_M || attr_arch == TAG_CPU_ARCH_V7E_M || attr_arch == TAG_CPU_ARCH_V8M_BASE || attr_arch == TAG_CPU_ARCH_V8M_MAIN || attr_arch == TAG_CPU_ARCH_V8_1M_MAIN || attr_profile == 'M')) is_m = true; /* Look for attributes that indicate support for ARMv8.1-m PACBTI. */ if (!tdesc_has_registers (tdesc) && is_m) { int attr_pac_extension = bfd_elf_get_obj_attr_int (info.abfd, OBJ_ATTR_PROC, Tag_PAC_extension); int attr_bti_extension = bfd_elf_get_obj_attr_int (info.abfd, OBJ_ATTR_PROC, Tag_BTI_extension); int attr_pacret_use = bfd_elf_get_obj_attr_int (info.abfd, OBJ_ATTR_PROC, Tag_PACRET_use); int attr_bti_use = bfd_elf_get_obj_attr_int (info.abfd, OBJ_ATTR_PROC, Tag_BTI_use); if (attr_pac_extension != 0 || attr_bti_extension != 0 || attr_pacret_use != 0 || attr_bti_use != 0) have_pacbti = true; } #endif } if (fp_model == ARM_FLOAT_AUTO) { switch (e_flags & (EF_ARM_SOFT_FLOAT | EF_ARM_VFP_FLOAT)) { case 0: /* Leave it as "auto". Strictly speaking this case means FPA, but almost nobody uses that now, and many toolchains fail to set the appropriate bits for the floating-point model they use. */ break; case EF_ARM_SOFT_FLOAT: fp_model = ARM_FLOAT_SOFT_FPA; break; case EF_ARM_VFP_FLOAT: fp_model = ARM_FLOAT_VFP; break; case EF_ARM_SOFT_FLOAT | EF_ARM_VFP_FLOAT: fp_model = ARM_FLOAT_SOFT_VFP; break; } } if (e_flags & EF_ARM_BE8) info.byte_order_for_code = BFD_ENDIAN_LITTLE; break; default: /* Leave it as "auto". */ break; } } /* Check any target description for validity. */ if (tdesc_has_registers (tdesc)) { /* For most registers we require GDB's default names; but also allow the numeric names for sp / lr / pc, as a convenience. */ static const char *const arm_sp_names[] = { "r13", "sp", NULL }; static const char *const arm_lr_names[] = { "r14", "lr", NULL }; static const char *const arm_pc_names[] = { "r15", "pc", NULL }; const struct tdesc_feature *feature; int valid_p; feature = tdesc_find_feature (tdesc, "org.gnu.gdb.arm.core"); if (feature == NULL) { feature = tdesc_find_feature (tdesc, "org.gnu.gdb.arm.m-profile"); if (feature == NULL) return NULL; else is_m = true; } tdesc_data = tdesc_data_alloc (); valid_p = 1; for (i = 0; i < ARM_SP_REGNUM; i++) valid_p &= tdesc_numbered_register (feature, tdesc_data.get (), i, arm_register_names[i]); valid_p &= tdesc_numbered_register_choices (feature, tdesc_data.get (), ARM_SP_REGNUM, arm_sp_names); valid_p &= tdesc_numbered_register_choices (feature, tdesc_data.get (), ARM_LR_REGNUM, arm_lr_names); valid_p &= tdesc_numbered_register_choices (feature, tdesc_data.get (), ARM_PC_REGNUM, arm_pc_names); if (is_m) valid_p &= tdesc_numbered_register (feature, tdesc_data.get (), ARM_PS_REGNUM, "xpsr"); else valid_p &= tdesc_numbered_register (feature, tdesc_data.get (), ARM_PS_REGNUM, "cpsr"); if (!valid_p) return NULL; if (is_m) { feature = tdesc_find_feature (tdesc, "org.gnu.gdb.arm.m-system"); if (feature != nullptr) { /* MSP */ valid_p &= tdesc_numbered_register (feature, tdesc_data.get (), register_count, "msp"); if (!valid_p) { warning (_("M-profile m-system feature is missing required register msp.")); return nullptr; } have_m_profile_msp = true; m_profile_msp_regnum = register_count++; /* PSP */ valid_p &= tdesc_numbered_register (feature, tdesc_data.get (), register_count, "psp"); if (!valid_p) { warning (_("M-profile m-system feature is missing required register psp.")); return nullptr; } m_profile_psp_regnum = register_count++; } } feature = tdesc_find_feature (tdesc, "org.gnu.gdb.arm.fpa"); if (feature != NULL) { valid_p = 1; for (i = ARM_F0_REGNUM; i <= ARM_FPS_REGNUM; i++) valid_p &= tdesc_numbered_register (feature, tdesc_data.get (), i, arm_register_names[i]); if (!valid_p) return NULL; } else have_fpa_registers = false; feature = tdesc_find_feature (tdesc, "org.gnu.gdb.xscale.iwmmxt"); if (feature != NULL) { static const char *const iwmmxt_names[] = { "wR0", "wR1", "wR2", "wR3", "wR4", "wR5", "wR6", "wR7", "wR8", "wR9", "wR10", "wR11", "wR12", "wR13", "wR14", "wR15", "wCID", "wCon", "wCSSF", "wCASF", "", "", "", "", "wCGR0", "wCGR1", "wCGR2", "wCGR3", "", "", "", "", }; valid_p = 1; for (i = ARM_WR0_REGNUM; i <= ARM_WR15_REGNUM; i++) valid_p &= tdesc_numbered_register (feature, tdesc_data.get (), i, iwmmxt_names[i - ARM_WR0_REGNUM]); /* Check for the control registers, but do not fail if they are missing. */ for (i = ARM_WC0_REGNUM; i <= ARM_WCASF_REGNUM; i++) tdesc_numbered_register (feature, tdesc_data.get (), i, iwmmxt_names[i - ARM_WR0_REGNUM]); for (i = ARM_WCGR0_REGNUM; i <= ARM_WCGR3_REGNUM; i++) valid_p &= tdesc_numbered_register (feature, tdesc_data.get (), i, iwmmxt_names[i - ARM_WR0_REGNUM]); if (!valid_p) return NULL; have_wmmx_registers = true; } /* If we have a VFP unit, check whether the single precision registers are present. If not, then we will synthesize them as pseudo registers. */ feature = tdesc_find_feature (tdesc, "org.gnu.gdb.arm.vfp"); if (feature != NULL) { static const char *const vfp_double_names[] = { "d0", "d1", "d2", "d3", "d4", "d5", "d6", "d7", "d8", "d9", "d10", "d11", "d12", "d13", "d14", "d15", "d16", "d17", "d18", "d19", "d20", "d21", "d22", "d23", "d24", "d25", "d26", "d27", "d28", "d29", "d30", "d31", }; /* Require the double precision registers. There must be either 16 or 32. */ valid_p = 1; for (i = 0; i < 32; i++) { valid_p &= tdesc_numbered_register (feature, tdesc_data.get (), ARM_D0_REGNUM + i, vfp_double_names[i]); if (!valid_p) break; } if (!valid_p && i == 16) valid_p = 1; /* Also require FPSCR. */ valid_p &= tdesc_numbered_register (feature, tdesc_data.get (), ARM_FPSCR_REGNUM, "fpscr"); if (!valid_p) return NULL; have_vfp = true; if (tdesc_unnumbered_register (feature, "s0") == 0) have_s_pseudos = true; vfp_register_count = i; /* If we have VFP, also check for NEON. The architecture allows NEON without VFP (integer vector operations only), but GDB does not support that. */ feature = tdesc_find_feature (tdesc, "org.gnu.gdb.arm.neon"); if (feature != NULL) { /* NEON requires 32 double-precision registers. */ if (i != 32) return NULL; /* If there are quad registers defined by the stub, use their type; otherwise (normally) provide them with the default type. */ if (tdesc_unnumbered_register (feature, "q0") == 0) have_q_pseudos = true; } } /* Check for the TLS register feature. */ feature = tdesc_find_feature (tdesc, "org.gnu.gdb.arm.tls"); if (feature != nullptr) { valid_p &= tdesc_numbered_register (feature, tdesc_data.get (), register_count, "tpidruro"); if (!valid_p) return nullptr; tls_regnum = register_count; register_count++; } /* Check for MVE after all the checks for GPR's, VFP and Neon. MVE (Helium) is an M-profile extension. */ if (is_m) { /* Do we have the MVE feature? */ feature = tdesc_find_feature (tdesc,"org.gnu.gdb.arm.m-profile-mve"); if (feature != nullptr) { /* If we have MVE, we must always have the VPR register. */ valid_p &= tdesc_numbered_register (feature, tdesc_data.get (), register_count, "vpr"); if (!valid_p) { warning (_("MVE feature is missing required register vpr.")); return nullptr; } have_mve = true; mve_vpr_regnum = register_count; register_count++; /* We can't have Q pseudo registers available here, as that would mean we have NEON features, and that is only available on A and R profiles. */ gdb_assert (!have_q_pseudos); /* Given we have a M-profile target description, if MVE is enabled and there are VFP registers, we should have Q pseudo registers (Q0 ~ Q7). */ if (have_vfp) have_q_pseudos = true; } /* Do we have the ARMv8.1-m PACBTI feature? */ feature = tdesc_find_feature (tdesc, "org.gnu.gdb.arm.m-profile-pacbti"); if (feature != nullptr) { /* By advertising this feature, the target acknowledges the presence of the ARMv8.1-m PACBTI extensions. We don't care for any particular registers in this group, so the target is free to include whatever it deems appropriate. The expectation is for this feature to include the PAC keys. */ have_pacbti = true; } /* Do we have the Security extension? */ feature = tdesc_find_feature (tdesc, "org.gnu.gdb.arm.secext"); if (feature != nullptr) { /* Secure/Non-secure stack pointers. */ /* MSP_NS */ valid_p &= tdesc_numbered_register (feature, tdesc_data.get (), register_count, "msp_ns"); if (!valid_p) { warning (_("M-profile secext feature is missing required register msp_ns.")); return nullptr; } m_profile_msp_ns_regnum = register_count++; /* PSP_NS */ valid_p &= tdesc_numbered_register (feature, tdesc_data.get (), register_count, "psp_ns"); if (!valid_p) { warning (_("M-profile secext feature is missing required register psp_ns.")); return nullptr; } m_profile_psp_ns_regnum = register_count++; /* MSP_S */ valid_p &= tdesc_numbered_register (feature, tdesc_data.get (), register_count, "msp_s"); if (!valid_p) { warning (_("M-profile secext feature is missing required register msp_s.")); return nullptr; } m_profile_msp_s_regnum = register_count++; /* PSP_S */ valid_p &= tdesc_numbered_register (feature, tdesc_data.get (), register_count, "psp_s"); if (!valid_p) { warning (_("M-profile secext feature is missing required register psp_s.")); return nullptr; } m_profile_psp_s_regnum = register_count++; have_sec_ext = true; } } } /* If there is already a candidate, use it. */ for (best_arch = gdbarch_list_lookup_by_info (arches, &info); best_arch != NULL; best_arch = gdbarch_list_lookup_by_info (best_arch->next, &info)) { arm_gdbarch_tdep *tdep = gdbarch_tdep (best_arch->gdbarch); if (arm_abi != ARM_ABI_AUTO && arm_abi != tdep->arm_abi) continue; if (fp_model != ARM_FLOAT_AUTO && fp_model != tdep->fp_model) continue; /* There are various other properties in tdep that we do not need to check here: those derived from a target description, since gdbarches with a different target description are automatically disqualified. */ /* Do check is_m, though, since it might come from the binary. */ if (is_m != tdep->is_m) continue; /* Also check for ARMv8.1-m PACBTI support, since it might come from the binary. */ if (have_pacbti != tdep->have_pacbti) continue; /* Found a match. */ break; } if (best_arch != NULL) return best_arch->gdbarch; gdbarch *gdbarch = gdbarch_alloc (&info, gdbarch_tdep_up (new arm_gdbarch_tdep)); arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); /* Record additional information about the architecture we are defining. These are gdbarch discriminators, like the OSABI. */ tdep->arm_abi = arm_abi; tdep->fp_model = fp_model; tdep->is_m = is_m; tdep->have_sec_ext = have_sec_ext; tdep->have_fpa_registers = have_fpa_registers; tdep->have_wmmx_registers = have_wmmx_registers; gdb_assert (vfp_register_count == 0 || vfp_register_count == 16 || vfp_register_count == 32); tdep->vfp_register_count = vfp_register_count; tdep->have_s_pseudos = have_s_pseudos; tdep->have_q_pseudos = have_q_pseudos; tdep->have_neon = have_neon; tdep->tls_regnum = tls_regnum; /* Adjust the MVE feature settings. */ if (have_mve) { tdep->have_mve = true; tdep->mve_vpr_regnum = mve_vpr_regnum; } /* Adjust the PACBTI feature settings. */ tdep->have_pacbti = have_pacbti; /* Adjust the M-profile stack pointers settings. */ if (have_m_profile_msp) { tdep->m_profile_msp_regnum = m_profile_msp_regnum; tdep->m_profile_psp_regnum = m_profile_psp_regnum; tdep->m_profile_msp_ns_regnum = m_profile_msp_ns_regnum; tdep->m_profile_psp_ns_regnum = m_profile_psp_ns_regnum; tdep->m_profile_msp_s_regnum = m_profile_msp_s_regnum; tdep->m_profile_psp_s_regnum = m_profile_psp_s_regnum; } arm_register_g_packet_guesses (gdbarch); /* Breakpoints. */ switch (info.byte_order_for_code) { case BFD_ENDIAN_BIG: tdep->arm_breakpoint = arm_default_arm_be_breakpoint; tdep->arm_breakpoint_size = sizeof (arm_default_arm_be_breakpoint); tdep->thumb_breakpoint = arm_default_thumb_be_breakpoint; tdep->thumb_breakpoint_size = sizeof (arm_default_thumb_be_breakpoint); break; case BFD_ENDIAN_LITTLE: tdep->arm_breakpoint = arm_default_arm_le_breakpoint; tdep->arm_breakpoint_size = sizeof (arm_default_arm_le_breakpoint); tdep->thumb_breakpoint = arm_default_thumb_le_breakpoint; tdep->thumb_breakpoint_size = sizeof (arm_default_thumb_le_breakpoint); break; default: internal_error (_("arm_gdbarch_init: bad byte order for float format")); } /* On ARM targets char defaults to unsigned. */ set_gdbarch_char_signed (gdbarch, 0); /* wchar_t is unsigned under the AAPCS. */ if (tdep->arm_abi == ARM_ABI_AAPCS) set_gdbarch_wchar_signed (gdbarch, 0); else set_gdbarch_wchar_signed (gdbarch, 1); /* Compute type alignment. */ set_gdbarch_type_align (gdbarch, arm_type_align); /* Note: for displaced stepping, this includes the breakpoint, and one word of additional scratch space. This setting isn't used for anything beside displaced stepping at present. */ set_gdbarch_displaced_step_buffer_length (gdbarch, 4 * ARM_DISPLACED_MODIFIED_INSNS); set_gdbarch_max_insn_length (gdbarch, 4); /* This should be low enough for everything. */ tdep->lowest_pc = 0x20; tdep->jb_pc = -1; /* Longjump support not enabled by default. */ /* The default, for both APCS and AAPCS, is to return small structures in registers. */ tdep->struct_return = reg_struct_return; set_gdbarch_push_dummy_call (gdbarch, arm_push_dummy_call); set_gdbarch_frame_align (gdbarch, arm_frame_align); if (is_m) set_gdbarch_code_of_frame_writable (gdbarch, arm_code_of_frame_writable); set_gdbarch_write_pc (gdbarch, arm_write_pc); frame_base_set_default (gdbarch, &arm_normal_base); /* Address manipulation. */ set_gdbarch_addr_bits_remove (gdbarch, arm_addr_bits_remove); /* Advance PC across function entry code. */ set_gdbarch_skip_prologue (gdbarch, arm_skip_prologue); /* Detect whether PC is at a point where the stack has been destroyed. */ set_gdbarch_stack_frame_destroyed_p (gdbarch, arm_stack_frame_destroyed_p); /* Skip trampolines. */ set_gdbarch_skip_trampoline_code (gdbarch, arm_skip_stub); /* The stack grows downward. */ set_gdbarch_inner_than (gdbarch, core_addr_lessthan); /* Breakpoint manipulation. */ set_gdbarch_breakpoint_kind_from_pc (gdbarch, arm_breakpoint_kind_from_pc); set_gdbarch_sw_breakpoint_from_kind (gdbarch, arm_sw_breakpoint_from_kind); set_gdbarch_breakpoint_kind_from_current_state (gdbarch, arm_breakpoint_kind_from_current_state); /* Information about registers, etc. */ set_gdbarch_sp_regnum (gdbarch, ARM_SP_REGNUM); set_gdbarch_pc_regnum (gdbarch, ARM_PC_REGNUM); set_gdbarch_num_regs (gdbarch, register_count); set_gdbarch_register_type (gdbarch, arm_register_type); set_gdbarch_register_reggroup_p (gdbarch, arm_register_reggroup_p); /* This "info float" is FPA-specific. Use the generic version if we do not have FPA. */ if (tdep->have_fpa_registers) set_gdbarch_print_float_info (gdbarch, arm_print_float_info); /* Internal <-> external register number maps. */ set_gdbarch_dwarf2_reg_to_regnum (gdbarch, arm_dwarf_reg_to_regnum); set_gdbarch_register_sim_regno (gdbarch, arm_register_sim_regno); set_gdbarch_register_name (gdbarch, arm_register_name); /* Returning results. */ set_gdbarch_return_value_as_value (gdbarch, arm_return_value); /* Disassembly. */ set_gdbarch_print_insn (gdbarch, gdb_print_insn_arm); /* Minsymbol frobbing. */ set_gdbarch_elf_make_msymbol_special (gdbarch, arm_elf_make_msymbol_special); set_gdbarch_coff_make_msymbol_special (gdbarch, arm_coff_make_msymbol_special); set_gdbarch_record_special_symbol (gdbarch, arm_record_special_symbol); /* Thumb-2 IT block support. */ set_gdbarch_adjust_breakpoint_address (gdbarch, arm_adjust_breakpoint_address); /* Virtual tables. */ set_gdbarch_vbit_in_delta (gdbarch, 1); /* Hook in the ABI-specific overrides, if they have been registered. */ gdbarch_init_osabi (info, gdbarch); dwarf2_frame_set_init_reg (gdbarch, arm_dwarf2_frame_init_reg); /* Add some default predicates. */ if (is_m) frame_unwind_append_unwinder (gdbarch, &arm_m_exception_unwind); frame_unwind_append_unwinder (gdbarch, &arm_stub_unwind); dwarf2_append_unwinders (gdbarch); frame_unwind_append_unwinder (gdbarch, &arm_exidx_unwind); frame_unwind_append_unwinder (gdbarch, &arm_epilogue_frame_unwind); frame_unwind_append_unwinder (gdbarch, &arm_prologue_unwind); /* Now we have tuned the configuration, set a few final things, based on what the OS ABI has told us. */ /* If the ABI is not otherwise marked, assume the old GNU APCS. EABI binaries are always marked. */ if (tdep->arm_abi == ARM_ABI_AUTO) tdep->arm_abi = ARM_ABI_APCS; /* Watchpoints are not steppable. */ set_gdbarch_have_nonsteppable_watchpoint (gdbarch, 1); /* We used to default to FPA for generic ARM, but almost nobody uses that now, and we now provide a way for the user to force the model. So default to the most useful variant. */ if (tdep->fp_model == ARM_FLOAT_AUTO) tdep->fp_model = ARM_FLOAT_SOFT_FPA; if (tdep->jb_pc >= 0) set_gdbarch_get_longjmp_target (gdbarch, arm_get_longjmp_target); /* Floating point sizes and format. */ set_gdbarch_float_format (gdbarch, floatformats_ieee_single); if (tdep->fp_model == ARM_FLOAT_SOFT_FPA || tdep->fp_model == ARM_FLOAT_FPA) { set_gdbarch_double_format (gdbarch, floatformats_ieee_double_littlebyte_bigword); set_gdbarch_long_double_format (gdbarch, floatformats_ieee_double_littlebyte_bigword); } else { set_gdbarch_double_format (gdbarch, floatformats_ieee_double); set_gdbarch_long_double_format (gdbarch, floatformats_ieee_double); } /* Hook used to decorate frames with signed return addresses, only available for ARMv8.1-m PACBTI. */ if (is_m && have_pacbti) set_gdbarch_get_pc_address_flags (gdbarch, arm_get_pc_address_flags); if (tdesc_data != nullptr) { set_tdesc_pseudo_register_name (gdbarch, arm_register_name); tdesc_use_registers (gdbarch, tdesc, std::move (tdesc_data)); register_count = gdbarch_num_regs (gdbarch); /* Override tdesc_register_type to adjust the types of VFP registers for NEON. */ set_gdbarch_register_type (gdbarch, arm_register_type); } /* Initialize the pseudo register data. */ int num_pseudos = 0; if (tdep->have_s_pseudos) { /* VFP single precision pseudo registers (S0~S31). */ tdep->s_pseudo_base = register_count; tdep->s_pseudo_count = 32; num_pseudos += tdep->s_pseudo_count; if (tdep->have_q_pseudos) { /* NEON quad precision pseudo registers (Q0~Q15). */ tdep->q_pseudo_base = register_count + num_pseudos; if (have_neon) tdep->q_pseudo_count = 16; else if (have_mve) tdep->q_pseudo_count = ARM_MVE_NUM_Q_REGS; num_pseudos += tdep->q_pseudo_count; } } /* Do we have any MVE pseudo registers? */ if (have_mve) { tdep->mve_pseudo_base = register_count + num_pseudos; tdep->mve_pseudo_count = 1; num_pseudos += tdep->mve_pseudo_count; } /* Do we have any ARMv8.1-m PACBTI pseudo registers. */ if (have_pacbti) { tdep->pacbti_pseudo_base = register_count + num_pseudos; tdep->pacbti_pseudo_count = 1; num_pseudos += tdep->pacbti_pseudo_count; } /* Set some pseudo register hooks, if we have pseudo registers. */ if (tdep->have_s_pseudos || have_mve || have_pacbti) { set_gdbarch_num_pseudo_regs (gdbarch, num_pseudos); set_gdbarch_pseudo_register_read (gdbarch, arm_pseudo_read); set_gdbarch_pseudo_register_write (gdbarch, arm_pseudo_write); } /* Add standard register aliases. We add aliases even for those names which are used by the current architecture - it's simpler, and does no harm, since nothing ever lists user registers. */ for (i = 0; i < ARRAY_SIZE (arm_register_aliases); i++) user_reg_add (gdbarch, arm_register_aliases[i].name, value_of_arm_user_reg, &arm_register_aliases[i].regnum); set_gdbarch_disassembler_options (gdbarch, &arm_disassembler_options); set_gdbarch_valid_disassembler_options (gdbarch, disassembler_options_arm ()); set_gdbarch_gnu_triplet_regexp (gdbarch, arm_gnu_triplet_regexp); return gdbarch; } static void arm_dump_tdep (struct gdbarch *gdbarch, struct ui_file *file) { arm_gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); if (tdep == NULL) return; gdb_printf (file, _("arm_dump_tdep: fp_model = %i\n"), (int) tdep->fp_model); gdb_printf (file, _("arm_dump_tdep: have_fpa_registers = %i\n"), (int) tdep->have_fpa_registers); gdb_printf (file, _("arm_dump_tdep: have_wmmx_registers = %i\n"), (int) tdep->have_wmmx_registers); gdb_printf (file, _("arm_dump_tdep: vfp_register_count = %i\n"), (int) tdep->vfp_register_count); gdb_printf (file, _("arm_dump_tdep: have_s_pseudos = %s\n"), tdep->have_s_pseudos? "true" : "false"); gdb_printf (file, _("arm_dump_tdep: s_pseudo_base = %i\n"), (int) tdep->s_pseudo_base); gdb_printf (file, _("arm_dump_tdep: s_pseudo_count = %i\n"), (int) tdep->s_pseudo_count); gdb_printf (file, _("arm_dump_tdep: have_q_pseudos = %s\n"), tdep->have_q_pseudos? "true" : "false"); gdb_printf (file, _("arm_dump_tdep: q_pseudo_base = %i\n"), (int) tdep->q_pseudo_base); gdb_printf (file, _("arm_dump_tdep: q_pseudo_count = %i\n"), (int) tdep->q_pseudo_count); gdb_printf (file, _("arm_dump_tdep: have_neon = %i\n"), (int) tdep->have_neon); gdb_printf (file, _("arm_dump_tdep: have_mve = %s\n"), tdep->have_mve? "yes" : "no"); gdb_printf (file, _("arm_dump_tdep: mve_vpr_regnum = %i\n"), tdep->mve_vpr_regnum); gdb_printf (file, _("arm_dump_tdep: mve_pseudo_base = %i\n"), tdep->mve_pseudo_base); gdb_printf (file, _("arm_dump_tdep: mve_pseudo_count = %i\n"), tdep->mve_pseudo_count); gdb_printf (file, _("arm_dump_tdep: m_profile_msp_regnum = %i\n"), tdep->m_profile_msp_regnum); gdb_printf (file, _("arm_dump_tdep: m_profile_psp_regnum = %i\n"), tdep->m_profile_psp_regnum); gdb_printf (file, _("arm_dump_tdep: m_profile_msp_ns_regnum = %i\n"), tdep->m_profile_msp_ns_regnum); gdb_printf (file, _("arm_dump_tdep: m_profile_psp_ns_regnum = %i\n"), tdep->m_profile_psp_ns_regnum); gdb_printf (file, _("arm_dump_tdep: m_profile_msp_s_regnum = %i\n"), tdep->m_profile_msp_s_regnum); gdb_printf (file, _("arm_dump_tdep: m_profile_psp_s_regnum = %i\n"), tdep->m_profile_psp_s_regnum); gdb_printf (file, _("arm_dump_tdep: Lowest pc = 0x%lx\n"), (unsigned long) tdep->lowest_pc); gdb_printf (file, _("arm_dump_tdep: have_pacbti = %s\n"), tdep->have_pacbti? "yes" : "no"); gdb_printf (file, _("arm_dump_tdep: pacbti_pseudo_base = %i\n"), tdep->pacbti_pseudo_base); gdb_printf (file, _("arm_dump_tdep: pacbti_pseudo_count = %i\n"), tdep->pacbti_pseudo_count); gdb_printf (file, _("arm_dump_tdep: is_m = %s\n"), tdep->is_m? "yes" : "no"); } #if GDB_SELF_TEST namespace selftests { static void arm_record_test (void); static void arm_analyze_prologue_test (); } #endif void _initialize_arm_tdep (); void _initialize_arm_tdep () { long length; int i, j; char regdesc[1024], *rdptr = regdesc; size_t rest = sizeof (regdesc); gdbarch_register (bfd_arch_arm, arm_gdbarch_init, arm_dump_tdep); /* Add ourselves to objfile event chain. */ gdb::observers::new_objfile.attach (arm_exidx_new_objfile, "arm-tdep"); /* Register an ELF OS ABI sniffer for ARM binaries. */ gdbarch_register_osabi_sniffer (bfd_arch_arm, bfd_target_elf_flavour, arm_elf_osabi_sniffer); /* Add root prefix command for all "set arm"/"show arm" commands. */ add_setshow_prefix_cmd ("arm", no_class, _("Various ARM-specific commands."), _("Various ARM-specific commands."), &setarmcmdlist, &showarmcmdlist, &setlist, &showlist); arm_disassembler_options = xstrdup ("reg-names-std"); const disasm_options_t *disasm_options = &disassembler_options_arm ()->options; int num_disassembly_styles = 0; for (i = 0; disasm_options->name[i] != NULL; i++) if (startswith (disasm_options->name[i], "reg-names-")) num_disassembly_styles++; /* Initialize the array that will be passed to add_setshow_enum_cmd(). */ valid_disassembly_styles = XNEWVEC (const char *, num_disassembly_styles + 1); for (i = j = 0; disasm_options->name[i] != NULL; i++) if (startswith (disasm_options->name[i], "reg-names-")) { size_t offset = strlen ("reg-names-"); const char *style = disasm_options->name[i]; valid_disassembly_styles[j++] = &style[offset]; if (strcmp (&style[offset], "std") == 0) disassembly_style = &style[offset]; length = snprintf (rdptr, rest, "%s - %s\n", &style[offset], disasm_options->description[i]); rdptr += length; rest -= length; } /* Mark the end of valid options. */ valid_disassembly_styles[num_disassembly_styles] = NULL; /* Create the help text. */ std::string helptext = string_printf ("%s%s%s", _("The valid values are:\n"), regdesc, _("The default is \"std\".")); add_setshow_enum_cmd("disassembler", no_class, valid_disassembly_styles, &disassembly_style, _("Set the disassembly style."), _("Show the disassembly style."), helptext.c_str (), set_disassembly_style_sfunc, show_disassembly_style_sfunc, &setarmcmdlist, &showarmcmdlist); add_setshow_boolean_cmd ("apcs32", no_class, &arm_apcs_32, _("Set usage of ARM 32-bit mode."), _("Show usage of ARM 32-bit mode."), _("When off, a 26-bit PC will be used."), NULL, NULL, /* FIXME: i18n: Usage of ARM 32-bit mode is %s. */ &setarmcmdlist, &showarmcmdlist); /* Add a command to allow the user to force the FPU model. */ add_setshow_enum_cmd ("fpu", no_class, fp_model_strings, ¤t_fp_model, _("Set the floating point type."), _("Show the floating point type."), _("auto - Determine the FP typefrom the OS-ABI.\n\ softfpa - Software FP, mixed-endian doubles on little-endian ARMs.\n\ fpa - FPA co-processor (GCC compiled).\n\ softvfp - Software FP with pure-endian doubles.\n\ vfp - VFP co-processor."), set_fp_model_sfunc, show_fp_model, &setarmcmdlist, &showarmcmdlist); /* Add a command to allow the user to force the ABI. */ add_setshow_enum_cmd ("abi", class_support, arm_abi_strings, &arm_abi_string, _("Set the ABI."), _("Show the ABI."), NULL, arm_set_abi, arm_show_abi, &setarmcmdlist, &showarmcmdlist); /* Add two commands to allow the user to force the assumed execution mode. */ add_setshow_enum_cmd ("fallback-mode", class_support, arm_mode_strings, &arm_fallback_mode_string, _("Set the mode assumed when symbols are unavailable."), _("Show the mode assumed when symbols are unavailable."), NULL, NULL, arm_show_fallback_mode, &setarmcmdlist, &showarmcmdlist); add_setshow_enum_cmd ("force-mode", class_support, arm_mode_strings, &arm_force_mode_string, _("Set the mode assumed even when symbols are available."), _("Show the mode assumed even when symbols are available."), NULL, NULL, arm_show_force_mode, &setarmcmdlist, &showarmcmdlist); /* Add a command to stop triggering security exceptions when unwinding exception stacks. */ add_setshow_boolean_cmd ("unwind-secure-frames", no_class, &arm_unwind_secure_frames, _("Set usage of non-secure to secure exception stack unwinding."), _("Show usage of non-secure to secure exception stack unwinding."), _("When on, the debugger can trigger memory access traps."), NULL, arm_show_unwind_secure_frames, &setarmcmdlist, &showarmcmdlist); /* Debugging flag. */ add_setshow_boolean_cmd ("arm", class_maintenance, &arm_debug, _("Set ARM debugging."), _("Show ARM debugging."), _("When on, arm-specific debugging is enabled."), NULL, NULL, /* FIXME: i18n: "ARM debugging is %s. */ &setdebuglist, &showdebuglist); #if GDB_SELF_TEST selftests::register_test ("arm-record", selftests::arm_record_test); selftests::register_test ("arm_analyze_prologue", selftests::arm_analyze_prologue_test); #endif } /* ARM-reversible process record data structures. */ #define ARM_INSN_SIZE_BYTES 4 #define THUMB_INSN_SIZE_BYTES 2 #define THUMB2_INSN_SIZE_BYTES 4 /* Position of the bit within a 32-bit ARM instruction that defines whether the instruction is a load or store. */ #define INSN_S_L_BIT_NUM 20 #define REG_ALLOC(REGS, LENGTH, RECORD_BUF) \ do \ { \ unsigned int reg_len = LENGTH; \ if (reg_len) \ { \ REGS = XNEWVEC (uint32_t, reg_len); \ memcpy(®S[0], &RECORD_BUF[0], sizeof(uint32_t)*LENGTH); \ } \ } \ while (0) #define MEM_ALLOC(MEMS, LENGTH, RECORD_BUF) \ do \ { \ unsigned int mem_len = LENGTH; \ if (mem_len) \ { \ MEMS = XNEWVEC (struct arm_mem_r, mem_len); \ memcpy(&MEMS->len, &RECORD_BUF[0], \ sizeof(struct arm_mem_r) * LENGTH); \ } \ } \ while (0) /* Checks whether insn is already recorded or yet to be decoded. (boolean expression). */ #define INSN_RECORDED(ARM_RECORD) \ (0 != (ARM_RECORD)->reg_rec_count || 0 != (ARM_RECORD)->mem_rec_count) /* ARM memory record structure. */ struct arm_mem_r { uint32_t len; /* Record length. */ uint32_t addr; /* Memory address. */ }; /* ARM instruction record contains opcode of current insn and execution state (before entry to decode_insn()), contains list of to-be-modified registers and memory blocks (on return from decode_insn()). */ struct arm_insn_decode_record { struct gdbarch *gdbarch; struct regcache *regcache; CORE_ADDR this_addr; /* Address of the insn being decoded. */ uint32_t arm_insn; /* Should accommodate thumb. */ uint32_t cond; /* Condition code. */ uint32_t opcode; /* Insn opcode. */ uint32_t decode; /* Insn decode bits. */ uint32_t mem_rec_count; /* No of mem records. */ uint32_t reg_rec_count; /* No of reg records. */ uint32_t *arm_regs; /* Registers to be saved for this record. */ struct arm_mem_r *arm_mems; /* Memory to be saved for this record. */ }; /* Checks ARM SBZ and SBO mandatory fields. */ static int sbo_sbz (uint32_t insn, uint32_t bit_num, uint32_t len, uint32_t sbo) { uint32_t ones = bits (insn, bit_num - 1, (bit_num -1) + (len - 1)); if (!len) return 1; if (!sbo) ones = ~ones; while (ones) { if (!(ones & sbo)) { return 0; } ones = ones >> 1; } return 1; } enum arm_record_result { ARM_RECORD_SUCCESS = 0, ARM_RECORD_FAILURE = 1 }; enum arm_record_strx_t { ARM_RECORD_STRH=1, ARM_RECORD_STRD }; enum record_type_t { ARM_RECORD=1, THUMB_RECORD, THUMB2_RECORD }; static int arm_record_strx (arm_insn_decode_record *arm_insn_r, uint32_t *record_buf, uint32_t *record_buf_mem, arm_record_strx_t str_type) { struct regcache *reg_cache = arm_insn_r->regcache; ULONGEST u_regval[2]= {0}; uint32_t reg_src1 = 0, reg_src2 = 0; uint32_t immed_high = 0, immed_low = 0,offset_8 = 0, tgt_mem_addr = 0; arm_insn_r->opcode = bits (arm_insn_r->arm_insn, 21, 24); arm_insn_r->decode = bits (arm_insn_r->arm_insn, 4, 7); if (14 == arm_insn_r->opcode || 10 == arm_insn_r->opcode) { /* 1) Handle misc store, immediate offset. */ immed_low = bits (arm_insn_r->arm_insn, 0, 3); immed_high = bits (arm_insn_r->arm_insn, 8, 11); reg_src1 = bits (arm_insn_r->arm_insn, 16, 19); regcache_raw_read_unsigned (reg_cache, reg_src1, &u_regval[0]); if (ARM_PC_REGNUM == reg_src1) { /* If R15 was used as Rn, hence current PC+8. */ u_regval[0] = u_regval[0] + 8; } offset_8 = (immed_high << 4) | immed_low; /* Calculate target store address. */ if (14 == arm_insn_r->opcode) { tgt_mem_addr = u_regval[0] + offset_8; } else { tgt_mem_addr = u_regval[0] - offset_8; } if (ARM_RECORD_STRH == str_type) { record_buf_mem[0] = 2; record_buf_mem[1] = tgt_mem_addr; arm_insn_r->mem_rec_count = 1; } else if (ARM_RECORD_STRD == str_type) { record_buf_mem[0] = 4; record_buf_mem[1] = tgt_mem_addr; record_buf_mem[2] = 4; record_buf_mem[3] = tgt_mem_addr + 4; arm_insn_r->mem_rec_count = 2; } } else if (12 == arm_insn_r->opcode || 8 == arm_insn_r->opcode) { /* 2) Store, register offset. */ /* Get Rm. */ reg_src1 = bits (arm_insn_r->arm_insn, 0, 3); /* Get Rn. */ reg_src2 = bits (arm_insn_r->arm_insn, 16, 19); regcache_raw_read_unsigned (reg_cache, reg_src1, &u_regval[0]); regcache_raw_read_unsigned (reg_cache, reg_src2, &u_regval[1]); if (15 == reg_src2) { /* If R15 was used as Rn, hence current PC+8. */ u_regval[0] = u_regval[0] + 8; } /* Calculate target store address, Rn +/- Rm, register offset. */ if (12 == arm_insn_r->opcode) { tgt_mem_addr = u_regval[0] + u_regval[1]; } else { tgt_mem_addr = u_regval[1] - u_regval[0]; } if (ARM_RECORD_STRH == str_type) { record_buf_mem[0] = 2; record_buf_mem[1] = tgt_mem_addr; arm_insn_r->mem_rec_count = 1; } else if (ARM_RECORD_STRD == str_type) { record_buf_mem[0] = 4; record_buf_mem[1] = tgt_mem_addr; record_buf_mem[2] = 4; record_buf_mem[3] = tgt_mem_addr + 4; arm_insn_r->mem_rec_count = 2; } } else if (11 == arm_insn_r->opcode || 15 == arm_insn_r->opcode || 2 == arm_insn_r->opcode || 6 == arm_insn_r->opcode) { /* 3) Store, immediate pre-indexed. */ /* 5) Store, immediate post-indexed. */ immed_low = bits (arm_insn_r->arm_insn, 0, 3); immed_high = bits (arm_insn_r->arm_insn, 8, 11); offset_8 = (immed_high << 4) | immed_low; reg_src1 = bits (arm_insn_r->arm_insn, 16, 19); regcache_raw_read_unsigned (reg_cache, reg_src1, &u_regval[0]); /* Calculate target store address, Rn +/- Rm, register offset. */ if (15 == arm_insn_r->opcode || 6 == arm_insn_r->opcode) { tgt_mem_addr = u_regval[0] + offset_8; } else { tgt_mem_addr = u_regval[0] - offset_8; } if (ARM_RECORD_STRH == str_type) { record_buf_mem[0] = 2; record_buf_mem[1] = tgt_mem_addr; arm_insn_r->mem_rec_count = 1; } else if (ARM_RECORD_STRD == str_type) { record_buf_mem[0] = 4; record_buf_mem[1] = tgt_mem_addr; record_buf_mem[2] = 4; record_buf_mem[3] = tgt_mem_addr + 4; arm_insn_r->mem_rec_count = 2; } /* Record Rn also as it changes. */ *(record_buf) = bits (arm_insn_r->arm_insn, 16, 19); arm_insn_r->reg_rec_count = 1; } else if (9 == arm_insn_r->opcode || 13 == arm_insn_r->opcode || 0 == arm_insn_r->opcode || 4 == arm_insn_r->opcode) { /* 4) Store, register pre-indexed. */ /* 6) Store, register post -indexed. */ reg_src1 = bits (arm_insn_r->arm_insn, 0, 3); reg_src2 = bits (arm_insn_r->arm_insn, 16, 19); regcache_raw_read_unsigned (reg_cache, reg_src1, &u_regval[0]); regcache_raw_read_unsigned (reg_cache, reg_src2, &u_regval[1]); /* Calculate target store address, Rn +/- Rm, register offset. */ if (13 == arm_insn_r->opcode || 4 == arm_insn_r->opcode) { tgt_mem_addr = u_regval[0] + u_regval[1]; } else { tgt_mem_addr = u_regval[1] - u_regval[0]; } if (ARM_RECORD_STRH == str_type) { record_buf_mem[0] = 2; record_buf_mem[1] = tgt_mem_addr; arm_insn_r->mem_rec_count = 1; } else if (ARM_RECORD_STRD == str_type) { record_buf_mem[0] = 4; record_buf_mem[1] = tgt_mem_addr; record_buf_mem[2] = 4; record_buf_mem[3] = tgt_mem_addr + 4; arm_insn_r->mem_rec_count = 2; } /* Record Rn also as it changes. */ *(record_buf) = bits (arm_insn_r->arm_insn, 16, 19); arm_insn_r->reg_rec_count = 1; } return 0; } /* Handling ARM extension space insns. */ static int arm_record_extension_space (arm_insn_decode_record *arm_insn_r) { int ret = 0; /* Return value: -1:record failure ; 0:success */ uint32_t opcode1 = 0, opcode2 = 0, insn_op1 = 0; uint32_t record_buf[8], record_buf_mem[8]; uint32_t reg_src1 = 0; struct regcache *reg_cache = arm_insn_r->regcache; ULONGEST u_regval = 0; gdb_assert (!INSN_RECORDED(arm_insn_r)); /* Handle unconditional insn extension space. */ opcode1 = bits (arm_insn_r->arm_insn, 20, 27); opcode2 = bits (arm_insn_r->arm_insn, 4, 7); if (arm_insn_r->cond) { /* PLD has no affect on architectural state, it just affects the caches. */ if (5 == ((opcode1 & 0xE0) >> 5)) { /* BLX(1) */ record_buf[0] = ARM_PS_REGNUM; record_buf[1] = ARM_LR_REGNUM; arm_insn_r->reg_rec_count = 2; } /* STC2, LDC2, MCR2, MRC2, CDP2: , co-processor insn. */ } opcode1 = bits (arm_insn_r->arm_insn, 25, 27); if (3 == opcode1 && bit (arm_insn_r->arm_insn, 4)) { ret = -1; /* Undefined instruction on ARM V5; need to handle if later versions define it. */ } opcode1 = bits (arm_insn_r->arm_insn, 24, 27); opcode2 = bits (arm_insn_r->arm_insn, 4, 7); insn_op1 = bits (arm_insn_r->arm_insn, 20, 23); /* Handle arithmetic insn extension space. */ if (!opcode1 && 9 == opcode2 && 1 != arm_insn_r->cond && !INSN_RECORDED(arm_insn_r)) { /* Handle MLA(S) and MUL(S). */ if (in_inclusive_range (insn_op1, 0U, 3U)) { record_buf[0] = bits (arm_insn_r->arm_insn, 12, 15); record_buf[1] = ARM_PS_REGNUM; arm_insn_r->reg_rec_count = 2; } else if (in_inclusive_range (insn_op1, 4U, 15U)) { /* Handle SMLAL(S), SMULL(S), UMLAL(S), UMULL(S). */ record_buf[0] = bits (arm_insn_r->arm_insn, 16, 19); record_buf[1] = bits (arm_insn_r->arm_insn, 12, 15); record_buf[2] = ARM_PS_REGNUM; arm_insn_r->reg_rec_count = 3; } } opcode1 = bits (arm_insn_r->arm_insn, 26, 27); opcode2 = bits (arm_insn_r->arm_insn, 23, 24); insn_op1 = bits (arm_insn_r->arm_insn, 21, 22); /* Handle control insn extension space. */ if (!opcode1 && 2 == opcode2 && !bit (arm_insn_r->arm_insn, 20) && 1 != arm_insn_r->cond && !INSN_RECORDED(arm_insn_r)) { if (!bit (arm_insn_r->arm_insn,25)) { if (!bits (arm_insn_r->arm_insn, 4, 7)) { if ((0 == insn_op1) || (2 == insn_op1)) { /* MRS. */ record_buf[0] = bits (arm_insn_r->arm_insn, 12, 15); arm_insn_r->reg_rec_count = 1; } else if (1 == insn_op1) { /* CSPR is going to be changed. */ record_buf[0] = ARM_PS_REGNUM; arm_insn_r->reg_rec_count = 1; } else if (3 == insn_op1) { /* SPSR is going to be changed. */ /* We need to get SPSR value, which is yet to be done. */ return -1; } } else if (1 == bits (arm_insn_r->arm_insn, 4, 7)) { if (1 == insn_op1) { /* BX. */ record_buf[0] = ARM_PS_REGNUM; arm_insn_r->reg_rec_count = 1; } else if (3 == insn_op1) { /* CLZ. */ record_buf[0] = bits (arm_insn_r->arm_insn, 12, 15); arm_insn_r->reg_rec_count = 1; } } else if (3 == bits (arm_insn_r->arm_insn, 4, 7)) { /* BLX. */ record_buf[0] = ARM_PS_REGNUM; record_buf[1] = ARM_LR_REGNUM; arm_insn_r->reg_rec_count = 2; } else if (5 == bits (arm_insn_r->arm_insn, 4, 7)) { /* QADD, QSUB, QDADD, QDSUB */ record_buf[0] = ARM_PS_REGNUM; record_buf[1] = bits (arm_insn_r->arm_insn, 12, 15); arm_insn_r->reg_rec_count = 2; } else if (7 == bits (arm_insn_r->arm_insn, 4, 7)) { /* BKPT. */ record_buf[0] = ARM_PS_REGNUM; record_buf[1] = ARM_LR_REGNUM; arm_insn_r->reg_rec_count = 2; /* Save SPSR also;how? */ return -1; } else if(8 == bits (arm_insn_r->arm_insn, 4, 7) || 10 == bits (arm_insn_r->arm_insn, 4, 7) || 12 == bits (arm_insn_r->arm_insn, 4, 7) || 14 == bits (arm_insn_r->arm_insn, 4, 7) ) { if (0 == insn_op1 || 1 == insn_op1) { /* SMLA, SMLAW, SMULW. */ /* We dont do optimization for SMULW where we need only Rd. */ record_buf[0] = bits (arm_insn_r->arm_insn, 12, 15); record_buf[1] = ARM_PS_REGNUM; arm_insn_r->reg_rec_count = 2; } else if (2 == insn_op1) { /* SMLAL. */ record_buf[0] = bits (arm_insn_r->arm_insn, 12, 15); record_buf[1] = bits (arm_insn_r->arm_insn, 16, 19); arm_insn_r->reg_rec_count = 2; } else if (3 == insn_op1) { /* SMUL. */ record_buf[0] = bits (arm_insn_r->arm_insn, 12, 15); arm_insn_r->reg_rec_count = 1; } } } else { /* MSR : immediate form. */ if (1 == insn_op1) { /* CSPR is going to be changed. */ record_buf[0] = ARM_PS_REGNUM; arm_insn_r->reg_rec_count = 1; } else if (3 == insn_op1) { /* SPSR is going to be changed. */ /* we need to get SPSR value, which is yet to be done */ return -1; } } } opcode1 = bits (arm_insn_r->arm_insn, 25, 27); opcode2 = bits (arm_insn_r->arm_insn, 20, 24); insn_op1 = bits (arm_insn_r->arm_insn, 5, 6); /* Handle load/store insn extension space. */ if (!opcode1 && bit (arm_insn_r->arm_insn, 7) && bit (arm_insn_r->arm_insn, 4) && 1 != arm_insn_r->cond && !INSN_RECORDED(arm_insn_r)) { /* SWP/SWPB. */ if (0 == insn_op1) { /* These insn, changes register and memory as well. */ /* SWP or SWPB insn. */ /* Get memory address given by Rn. */ reg_src1 = bits (arm_insn_r->arm_insn, 16, 19); regcache_raw_read_unsigned (reg_cache, reg_src1, &u_regval); /* SWP insn ?, swaps word. */ if (8 == arm_insn_r->opcode) { record_buf_mem[0] = 4; } else { /* SWPB insn, swaps only byte. */ record_buf_mem[0] = 1; } record_buf_mem[1] = u_regval; arm_insn_r->mem_rec_count = 1; record_buf[0] = bits (arm_insn_r->arm_insn, 12, 15); arm_insn_r->reg_rec_count = 1; } else if (1 == insn_op1 && !bit (arm_insn_r->arm_insn, 20)) { /* STRH. */ arm_record_strx(arm_insn_r, &record_buf[0], &record_buf_mem[0], ARM_RECORD_STRH); } else if (2 == insn_op1 && !bit (arm_insn_r->arm_insn, 20)) { /* LDRD. */ record_buf[0] = bits (arm_insn_r->arm_insn, 12, 15); record_buf[1] = record_buf[0] + 1; arm_insn_r->reg_rec_count = 2; } else if (3 == insn_op1 && !bit (arm_insn_r->arm_insn, 20)) { /* STRD. */ arm_record_strx(arm_insn_r, &record_buf[0], &record_buf_mem[0], ARM_RECORD_STRD); } else if (bit (arm_insn_r->arm_insn, 20) && insn_op1 <= 3) { /* LDRH, LDRSB, LDRSH. */ record_buf[0] = bits (arm_insn_r->arm_insn, 12, 15); arm_insn_r->reg_rec_count = 1; } } opcode1 = bits (arm_insn_r->arm_insn, 23, 27); if (24 == opcode1 && bit (arm_insn_r->arm_insn, 21) && !INSN_RECORDED(arm_insn_r)) { ret = -1; /* Handle coprocessor insn extension space. */ } /* To be done for ARMv5 and later; as of now we return -1. */ if (-1 == ret) return ret; REG_ALLOC (arm_insn_r->arm_regs, arm_insn_r->reg_rec_count, record_buf); MEM_ALLOC (arm_insn_r->arm_mems, arm_insn_r->mem_rec_count, record_buf_mem); return ret; } /* Handling opcode 000 insns. */ static int arm_record_data_proc_misc_ld_str (arm_insn_decode_record *arm_insn_r) { struct regcache *reg_cache = arm_insn_r->regcache; uint32_t record_buf[8], record_buf_mem[8]; ULONGEST u_regval[2] = {0}; uint32_t reg_src1 = 0; uint32_t opcode1 = 0; arm_insn_r->opcode = bits (arm_insn_r->arm_insn, 21, 24); arm_insn_r->decode = bits (arm_insn_r->arm_insn, 4, 7); opcode1 = bits (arm_insn_r->arm_insn, 20, 24); if (!((opcode1 & 0x19) == 0x10)) { /* Data-processing (register) and Data-processing (register-shifted register */ /* Out of 11 shifter operands mode, all the insn modifies destination register, which is specified by 13-16 decode. */ record_buf[0] = bits (arm_insn_r->arm_insn, 12, 15); record_buf[1] = ARM_PS_REGNUM; arm_insn_r->reg_rec_count = 2; } else if ((arm_insn_r->decode < 8) && ((opcode1 & 0x19) == 0x10)) { /* Miscellaneous instructions */ if (3 == arm_insn_r->decode && 0x12 == opcode1 && sbo_sbz (arm_insn_r->arm_insn, 9, 12, 1)) { /* Handle BLX, branch and link/exchange. */ if (9 == arm_insn_r->opcode) { /* Branch is chosen by setting T bit of CSPR, bitp[0] of Rm, and R14 stores the return address. */ record_buf[0] = ARM_PS_REGNUM; record_buf[1] = ARM_LR_REGNUM; arm_insn_r->reg_rec_count = 2; } } else if (7 == arm_insn_r->decode && 0x12 == opcode1) { /* Handle enhanced software breakpoint insn, BKPT. */ /* CPSR is changed to be executed in ARM state, disabling normal interrupts, entering abort mode. */ /* According to high vector configuration PC is set. */ /* user hit breakpoint and type reverse, in that case, we need to go back with previous CPSR and Program Counter. */ record_buf[0] = ARM_PS_REGNUM; record_buf[1] = ARM_LR_REGNUM; arm_insn_r->reg_rec_count = 2; /* Save SPSR also; how? */ return -1; } else if (1 == arm_insn_r->decode && 0x12 == opcode1 && sbo_sbz (arm_insn_r->arm_insn, 9, 12, 1)) { /* Handle BX, branch and link/exchange. */ /* Branch is chosen by setting T bit of CSPR, bitp[0] of Rm. */ record_buf[0] = ARM_PS_REGNUM; arm_insn_r->reg_rec_count = 1; } else if (1 == arm_insn_r->decode && 0x16 == opcode1 && sbo_sbz (arm_insn_r->arm_insn, 9, 4, 1) && sbo_sbz (arm_insn_r->arm_insn, 17, 4, 1)) { /* Count leading zeros: CLZ. */ record_buf[0] = bits (arm_insn_r->arm_insn, 12, 15); arm_insn_r->reg_rec_count = 1; } else if (!bit (arm_insn_r->arm_insn, INSN_S_L_BIT_NUM) && (8 == arm_insn_r->opcode || 10 == arm_insn_r->opcode) && sbo_sbz (arm_insn_r->arm_insn, 17, 4, 1) && sbo_sbz (arm_insn_r->arm_insn, 1, 12, 0)) { /* Handle MRS insn. */ record_buf[0] = bits (arm_insn_r->arm_insn, 12, 15); arm_insn_r->reg_rec_count = 1; } } else if (9 == arm_insn_r->decode && opcode1 < 0x10) { /* Multiply and multiply-accumulate */ /* Handle multiply instructions. */ /* MLA, MUL, SMLAL, SMULL, UMLAL, UMULL. */ if (0 == arm_insn_r->opcode || 1 == arm_insn_r->opcode) { /* Handle MLA and MUL. */ record_buf[0] = bits (arm_insn_r->arm_insn, 16, 19); record_buf[1] = ARM_PS_REGNUM; arm_insn_r->reg_rec_count = 2; } else if (4 <= arm_insn_r->opcode && 7 >= arm_insn_r->opcode) { /* Handle SMLAL, SMULL, UMLAL, UMULL. */ record_buf[0] = bits (arm_insn_r->arm_insn, 16, 19); record_buf[1] = bits (arm_insn_r->arm_insn, 12, 15); record_buf[2] = ARM_PS_REGNUM; arm_insn_r->reg_rec_count = 3; } } else if (9 == arm_insn_r->decode && opcode1 > 0x10) { /* Synchronization primitives */ /* Handling SWP, SWPB. */ /* These insn, changes register and memory as well. */ /* SWP or SWPB insn. */ reg_src1 = bits (arm_insn_r->arm_insn, 16, 19); regcache_raw_read_unsigned (reg_cache, reg_src1, &u_regval[0]); /* SWP insn ?, swaps word. */ if (8 == arm_insn_r->opcode) { record_buf_mem[0] = 4; } else { /* SWPB insn, swaps only byte. */ record_buf_mem[0] = 1; } record_buf_mem[1] = u_regval[0]; arm_insn_r->mem_rec_count = 1; record_buf[0] = bits (arm_insn_r->arm_insn, 12, 15); arm_insn_r->reg_rec_count = 1; } else if (11 == arm_insn_r->decode || 13 == arm_insn_r->decode || 15 == arm_insn_r->decode) { if ((opcode1 & 0x12) == 2) { /* Extra load/store (unprivileged) */ return -1; } else { /* Extra load/store */ switch (bits (arm_insn_r->arm_insn, 5, 6)) { case 1: if ((opcode1 & 0x05) == 0x0 || (opcode1 & 0x05) == 0x4) { /* STRH (register), STRH (immediate) */ arm_record_strx (arm_insn_r, &record_buf[0], &record_buf_mem[0], ARM_RECORD_STRH); } else if ((opcode1 & 0x05) == 0x1) { /* LDRH (register) */ record_buf[0] = bits (arm_insn_r->arm_insn, 12, 15); arm_insn_r->reg_rec_count = 1; if (bit (arm_insn_r->arm_insn, 21)) { /* Write back to Rn. */ record_buf[arm_insn_r->reg_rec_count++] = bits (arm_insn_r->arm_insn, 16, 19); } } else if ((opcode1 & 0x05) == 0x5) { /* LDRH (immediate), LDRH (literal) */ int rn = bits (arm_insn_r->arm_insn, 16, 19); record_buf[0] = bits (arm_insn_r->arm_insn, 12, 15); arm_insn_r->reg_rec_count = 1; if (rn != 15) { /*LDRH (immediate) */ if (bit (arm_insn_r->arm_insn, 21)) { /* Write back to Rn. */ record_buf[arm_insn_r->reg_rec_count++] = rn; } } } else return -1; break; case 2: if ((opcode1 & 0x05) == 0x0) { /* LDRD (register) */ record_buf[0] = bits (arm_insn_r->arm_insn, 12, 15); record_buf[1] = record_buf[0] + 1; arm_insn_r->reg_rec_count = 2; if (bit (arm_insn_r->arm_insn, 21)) { /* Write back to Rn. */ record_buf[arm_insn_r->reg_rec_count++] = bits (arm_insn_r->arm_insn, 16, 19); } } else if ((opcode1 & 0x05) == 0x1) { /* LDRSB (register) */ record_buf[0] = bits (arm_insn_r->arm_insn, 12, 15); arm_insn_r->reg_rec_count = 1; if (bit (arm_insn_r->arm_insn, 21)) { /* Write back to Rn. */ record_buf[arm_insn_r->reg_rec_count++] = bits (arm_insn_r->arm_insn, 16, 19); } } else if ((opcode1 & 0x05) == 0x4 || (opcode1 & 0x05) == 0x5) { /* LDRD (immediate), LDRD (literal), LDRSB (immediate), LDRSB (literal) */ int rn = bits (arm_insn_r->arm_insn, 16, 19); record_buf[0] = bits (arm_insn_r->arm_insn, 12, 15); arm_insn_r->reg_rec_count = 1; if (rn != 15) { /*LDRD (immediate), LDRSB (immediate) */ if (bit (arm_insn_r->arm_insn, 21)) { /* Write back to Rn. */ record_buf[arm_insn_r->reg_rec_count++] = rn; } } } else return -1; break; case 3: if ((opcode1 & 0x05) == 0x0) { /* STRD (register) */ arm_record_strx (arm_insn_r, &record_buf[0], &record_buf_mem[0], ARM_RECORD_STRD); } else if ((opcode1 & 0x05) == 0x1) { /* LDRSH (register) */ record_buf[0] = bits (arm_insn_r->arm_insn, 12, 15); arm_insn_r->reg_rec_count = 1; if (bit (arm_insn_r->arm_insn, 21)) { /* Write back to Rn. */ record_buf[arm_insn_r->reg_rec_count++] = bits (arm_insn_r->arm_insn, 16, 19); } } else if ((opcode1 & 0x05) == 0x4) { /* STRD (immediate) */ arm_record_strx (arm_insn_r, &record_buf[0], &record_buf_mem[0], ARM_RECORD_STRD); } else if ((opcode1 & 0x05) == 0x5) { /* LDRSH (immediate), LDRSH (literal) */ record_buf[0] = bits (arm_insn_r->arm_insn, 12, 15); arm_insn_r->reg_rec_count = 1; if (bit (arm_insn_r->arm_insn, 21)) { /* Write back to Rn. */ record_buf[arm_insn_r->reg_rec_count++] = bits (arm_insn_r->arm_insn, 16, 19); } } else return -1; break; default: return -1; } } } else { return -1; } REG_ALLOC (arm_insn_r->arm_regs, arm_insn_r->reg_rec_count, record_buf); MEM_ALLOC (arm_insn_r->arm_mems, arm_insn_r->mem_rec_count, record_buf_mem); return 0; } /* Handling opcode 001 insns. */ static int arm_record_data_proc_imm (arm_insn_decode_record *arm_insn_r) { uint32_t record_buf[8], record_buf_mem[8]; arm_insn_r->opcode = bits (arm_insn_r->arm_insn, 21, 24); arm_insn_r->decode = bits (arm_insn_r->arm_insn, 4, 7); if ((9 == arm_insn_r->opcode || 11 == arm_insn_r->opcode) && 2 == bits (arm_insn_r->arm_insn, 20, 21) && sbo_sbz (arm_insn_r->arm_insn, 13, 4, 1) ) { /* Handle MSR insn. */ if (9 == arm_insn_r->opcode) { /* CSPR is going to be changed. */ record_buf[0] = ARM_PS_REGNUM; arm_insn_r->reg_rec_count = 1; } else { /* SPSR is going to be changed. */ } } else if (arm_insn_r->opcode <= 15) { /* Normal data processing insns. */ /* Out of 11 shifter operands mode, all the insn modifies destination register, which is specified by 13-16 decode. */ record_buf[0] = bits (arm_insn_r->arm_insn, 12, 15); record_buf[1] = ARM_PS_REGNUM; arm_insn_r->reg_rec_count = 2; } else { return -1; } REG_ALLOC (arm_insn_r->arm_regs, arm_insn_r->reg_rec_count, record_buf); MEM_ALLOC (arm_insn_r->arm_mems, arm_insn_r->mem_rec_count, record_buf_mem); return 0; } static int arm_record_media (arm_insn_decode_record *arm_insn_r) { uint32_t record_buf[8]; switch (bits (arm_insn_r->arm_insn, 22, 24)) { case 0: /* Parallel addition and subtraction, signed */ case 1: /* Parallel addition and subtraction, unsigned */ case 2: case 3: /* Packing, unpacking, saturation and reversal */ { int rd = bits (arm_insn_r->arm_insn, 12, 15); record_buf[arm_insn_r->reg_rec_count++] = rd; } break; case 4: case 5: /* Signed multiplies */ { int rd = bits (arm_insn_r->arm_insn, 16, 19); unsigned int op1 = bits (arm_insn_r->arm_insn, 20, 22); record_buf[arm_insn_r->reg_rec_count++] = rd; if (op1 == 0x0) record_buf[arm_insn_r->reg_rec_count++] = ARM_PS_REGNUM; else if (op1 == 0x4) record_buf[arm_insn_r->reg_rec_count++] = bits (arm_insn_r->arm_insn, 12, 15); } break; case 6: { if (bit (arm_insn_r->arm_insn, 21) && bits (arm_insn_r->arm_insn, 5, 6) == 0x2) { /* SBFX */ record_buf[arm_insn_r->reg_rec_count++] = bits (arm_insn_r->arm_insn, 12, 15); } else if (bits (arm_insn_r->arm_insn, 20, 21) == 0x0 && bits (arm_insn_r->arm_insn, 5, 7) == 0x0) { /* USAD8 and USADA8 */ record_buf[arm_insn_r->reg_rec_count++] = bits (arm_insn_r->arm_insn, 16, 19); } } break; case 7: { if (bits (arm_insn_r->arm_insn, 20, 21) == 0x3 && bits (arm_insn_r->arm_insn, 5, 7) == 0x7) { /* Permanently UNDEFINED */ return -1; } else { /* BFC, BFI and UBFX */ record_buf[arm_insn_r->reg_rec_count++] = bits (arm_insn_r->arm_insn, 12, 15); } } break; default: return -1; } REG_ALLOC (arm_insn_r->arm_regs, arm_insn_r->reg_rec_count, record_buf); return 0; } /* Handle ARM mode instructions with opcode 010. */ static int arm_record_ld_st_imm_offset (arm_insn_decode_record *arm_insn_r) { struct regcache *reg_cache = arm_insn_r->regcache; uint32_t reg_base , reg_dest; uint32_t offset_12, tgt_mem_addr; uint32_t record_buf[8], record_buf_mem[8]; unsigned char wback; ULONGEST u_regval; /* Calculate wback. */ wback = (bit (arm_insn_r->arm_insn, 24) == 0) || (bit (arm_insn_r->arm_insn, 21) == 1); arm_insn_r->reg_rec_count = 0; reg_base = bits (arm_insn_r->arm_insn, 16, 19); if (bit (arm_insn_r->arm_insn, INSN_S_L_BIT_NUM)) { /* LDR (immediate), LDR (literal), LDRB (immediate), LDRB (literal), LDRBT and LDRT. */ reg_dest = bits (arm_insn_r->arm_insn, 12, 15); record_buf[arm_insn_r->reg_rec_count++] = reg_dest; /* The LDR instruction is capable of doing branching. If MOV LR, PC preceeds a LDR instruction having R15 as reg_base, it emulates a branch and link instruction, and hence we need to save CPSR and PC as well. */ if (ARM_PC_REGNUM == reg_dest) record_buf[arm_insn_r->reg_rec_count++] = ARM_PS_REGNUM; /* If wback is true, also save the base register, which is going to be written to. */ if (wback) record_buf[arm_insn_r->reg_rec_count++] = reg_base; } else { /* STR (immediate), STRB (immediate), STRBT and STRT. */ offset_12 = bits (arm_insn_r->arm_insn, 0, 11); regcache_raw_read_unsigned (reg_cache, reg_base, &u_regval); /* Handle bit U. */ if (bit (arm_insn_r->arm_insn, 23)) { /* U == 1: Add the offset. */ tgt_mem_addr = (uint32_t) u_regval + offset_12; } else { /* U == 0: subtract the offset. */ tgt_mem_addr = (uint32_t) u_regval - offset_12; } /* Bit 22 tells us whether the store instruction writes 1 byte or 4 bytes. */ if (bit (arm_insn_r->arm_insn, 22)) { /* STRB and STRBT: 1 byte. */ record_buf_mem[0] = 1; } else { /* STR and STRT: 4 bytes. */ record_buf_mem[0] = 4; } /* Handle bit P. */ if (bit (arm_insn_r->arm_insn, 24)) record_buf_mem[1] = tgt_mem_addr; else record_buf_mem[1] = (uint32_t) u_regval; arm_insn_r->mem_rec_count = 1; /* If wback is true, also save the base register, which is going to be written to. */ if (wback) record_buf[arm_insn_r->reg_rec_count++] = reg_base; } REG_ALLOC (arm_insn_r->arm_regs, arm_insn_r->reg_rec_count, record_buf); MEM_ALLOC (arm_insn_r->arm_mems, arm_insn_r->mem_rec_count, record_buf_mem); return 0; } /* Handling opcode 011 insns. */ static int arm_record_ld_st_reg_offset (arm_insn_decode_record *arm_insn_r) { struct regcache *reg_cache = arm_insn_r->regcache; uint32_t shift_imm = 0; uint32_t reg_src1 = 0, reg_src2 = 0, reg_dest = 0; uint32_t offset_12 = 0, tgt_mem_addr = 0; uint32_t record_buf[8], record_buf_mem[8]; LONGEST s_word; ULONGEST u_regval[2]; if (bit (arm_insn_r->arm_insn, 4)) return arm_record_media (arm_insn_r); arm_insn_r->opcode = bits (arm_insn_r->arm_insn, 21, 24); arm_insn_r->decode = bits (arm_insn_r->arm_insn, 4, 7); /* Handle enhanced store insns and LDRD DSP insn, order begins according to addressing modes for store insns STRH insn. */ /* LDR or STR? */ if (bit (arm_insn_r->arm_insn, INSN_S_L_BIT_NUM)) { reg_dest = bits (arm_insn_r->arm_insn, 12, 15); /* LDR insn has a capability to do branching, if MOV LR, PC is preceded by LDR insn having Rn as R15 in that case, it emulates branch and link insn, and hence we need to save CSPR and PC as well. */ if (15 != reg_dest) { record_buf[0] = bits (arm_insn_r->arm_insn, 12, 15); arm_insn_r->reg_rec_count = 1; } else { record_buf[0] = reg_dest; record_buf[1] = ARM_PS_REGNUM; arm_insn_r->reg_rec_count = 2; } } else { if (! bits (arm_insn_r->arm_insn, 4, 11)) { /* Store insn, register offset and register pre-indexed, register post-indexed. */ /* Get Rm. */ reg_src1 = bits (arm_insn_r->arm_insn, 0, 3); /* Get Rn. */ reg_src2 = bits (arm_insn_r->arm_insn, 16, 19); regcache_raw_read_unsigned (reg_cache, reg_src1 , &u_regval[0]); regcache_raw_read_unsigned (reg_cache, reg_src2 , &u_regval[1]); if (15 == reg_src2) { /* If R15 was used as Rn, hence current PC+8. */ /* Pre-indexed mode doesnt reach here ; illegal insn. */ u_regval[0] = u_regval[0] + 8; } /* Calculate target store address, Rn +/- Rm, register offset. */ /* U == 1. */ if (bit (arm_insn_r->arm_insn, 23)) { tgt_mem_addr = u_regval[0] + u_regval[1]; } else { tgt_mem_addr = u_regval[1] - u_regval[0]; } switch (arm_insn_r->opcode) { /* STR. */ case 8: case 12: /* STR. */ case 9: case 13: /* STRT. */ case 1: case 5: /* STR. */ case 0: case 4: record_buf_mem[0] = 4; break; /* STRB. */ case 10: case 14: /* STRB. */ case 11: case 15: /* STRBT. */ case 3: case 7: /* STRB. */ case 2: case 6: record_buf_mem[0] = 1; break; default: gdb_assert_not_reached ("no decoding pattern found"); break; } record_buf_mem[1] = tgt_mem_addr; arm_insn_r->mem_rec_count = 1; if (9 == arm_insn_r->opcode || 11 == arm_insn_r->opcode || 13 == arm_insn_r->opcode || 15 == arm_insn_r->opcode || 0 == arm_insn_r->opcode || 2 == arm_insn_r->opcode || 4 == arm_insn_r->opcode || 6 == arm_insn_r->opcode || 1 == arm_insn_r->opcode || 3 == arm_insn_r->opcode || 5 == arm_insn_r->opcode || 7 == arm_insn_r->opcode ) { /* Rn is going to be changed in pre-indexed mode and post-indexed mode as well. */ record_buf[0] = reg_src2; arm_insn_r->reg_rec_count = 1; } } else { /* Store insn, scaled register offset; scaled pre-indexed. */ offset_12 = bits (arm_insn_r->arm_insn, 5, 6); /* Get Rm. */ reg_src1 = bits (arm_insn_r->arm_insn, 0, 3); /* Get Rn. */ reg_src2 = bits (arm_insn_r->arm_insn, 16, 19); /* Get shift_imm. */ shift_imm = bits (arm_insn_r->arm_insn, 7, 11); regcache_raw_read_unsigned (reg_cache, reg_src1, &u_regval[0]); regcache_raw_read_signed (reg_cache, reg_src1, &s_word); regcache_raw_read_unsigned (reg_cache, reg_src2, &u_regval[1]); /* Offset_12 used as shift. */ switch (offset_12) { case 0: /* Offset_12 used as index. */ offset_12 = u_regval[0] << shift_imm; break; case 1: offset_12 = (!shift_imm)?0:u_regval[0] >> shift_imm; break; case 2: if (!shift_imm) { if (bit (u_regval[0], 31)) { offset_12 = 0xFFFFFFFF; } else { offset_12 = 0; } } else { /* This is arithmetic shift. */ offset_12 = s_word >> shift_imm; } break; case 3: if (!shift_imm) { regcache_raw_read_unsigned (reg_cache, ARM_PS_REGNUM, &u_regval[1]); /* Get C flag value and shift it by 31. */ offset_12 = (((bit (u_regval[1], 29)) << 31) \ | (u_regval[0]) >> 1); } else { offset_12 = (u_regval[0] >> shift_imm) \ | (u_regval[0] << (sizeof(uint32_t) - shift_imm)); } break; default: gdb_assert_not_reached ("no decoding pattern found"); break; } regcache_raw_read_unsigned (reg_cache, reg_src2, &u_regval[1]); /* bit U set. */ if (bit (arm_insn_r->arm_insn, 23)) { tgt_mem_addr = u_regval[1] + offset_12; } else { tgt_mem_addr = u_regval[1] - offset_12; } switch (arm_insn_r->opcode) { /* STR. */ case 8: case 12: /* STR. */ case 9: case 13: /* STRT. */ case 1: case 5: /* STR. */ case 0: case 4: record_buf_mem[0] = 4; break; /* STRB. */ case 10: case 14: /* STRB. */ case 11: case 15: /* STRBT. */ case 3: case 7: /* STRB. */ case 2: case 6: record_buf_mem[0] = 1; break; default: gdb_assert_not_reached ("no decoding pattern found"); break; } record_buf_mem[1] = tgt_mem_addr; arm_insn_r->mem_rec_count = 1; if (9 == arm_insn_r->opcode || 11 == arm_insn_r->opcode || 13 == arm_insn_r->opcode || 15 == arm_insn_r->opcode || 0 == arm_insn_r->opcode || 2 == arm_insn_r->opcode || 4 == arm_insn_r->opcode || 6 == arm_insn_r->opcode || 1 == arm_insn_r->opcode || 3 == arm_insn_r->opcode || 5 == arm_insn_r->opcode || 7 == arm_insn_r->opcode ) { /* Rn is going to be changed in register scaled pre-indexed mode,and scaled post indexed mode. */ record_buf[0] = reg_src2; arm_insn_r->reg_rec_count = 1; } } } REG_ALLOC (arm_insn_r->arm_regs, arm_insn_r->reg_rec_count, record_buf); MEM_ALLOC (arm_insn_r->arm_mems, arm_insn_r->mem_rec_count, record_buf_mem); return 0; } /* Handle ARM mode instructions with opcode 100. */ static int arm_record_ld_st_multiple (arm_insn_decode_record *arm_insn_r) { struct regcache *reg_cache = arm_insn_r->regcache; uint32_t register_count = 0, register_bits; uint32_t reg_base, addr_mode; uint32_t record_buf[24], record_buf_mem[48]; uint32_t wback; ULONGEST u_regval; /* Fetch the list of registers. */ register_bits = bits (arm_insn_r->arm_insn, 0, 15); arm_insn_r->reg_rec_count = 0; /* Fetch the base register that contains the address we are loading data to. */ reg_base = bits (arm_insn_r->arm_insn, 16, 19); /* Calculate wback. */ wback = (bit (arm_insn_r->arm_insn, 21) == 1); if (bit (arm_insn_r->arm_insn, INSN_S_L_BIT_NUM)) { /* LDM/LDMIA/LDMFD, LDMDA/LDMFA, LDMDB and LDMIB. */ /* Find out which registers are going to be loaded from memory. */ while (register_bits) { if (register_bits & 0x00000001) record_buf[arm_insn_r->reg_rec_count++] = register_count; register_bits = register_bits >> 1; register_count++; } /* If wback is true, also save the base register, which is going to be written to. */ if (wback) record_buf[arm_insn_r->reg_rec_count++] = reg_base; /* Save the CPSR register. */ record_buf[arm_insn_r->reg_rec_count++] = ARM_PS_REGNUM; } else { /* STM (STMIA, STMEA), STMDA (STMED), STMDB (STMFD) and STMIB (STMFA). */ addr_mode = bits (arm_insn_r->arm_insn, 23, 24); regcache_raw_read_unsigned (reg_cache, reg_base, &u_regval); /* Find out how many registers are going to be stored to memory. */ while (register_bits) { if (register_bits & 0x00000001) register_count++; register_bits = register_bits >> 1; } switch (addr_mode) { /* STMDA (STMED): Decrement after. */ case 0: record_buf_mem[1] = (uint32_t) u_regval - register_count * ARM_INT_REGISTER_SIZE + 4; break; /* STM (STMIA, STMEA): Increment after. */ case 1: record_buf_mem[1] = (uint32_t) u_regval; break; /* STMDB (STMFD): Decrement before. */ case 2: record_buf_mem[1] = (uint32_t) u_regval - register_count * ARM_INT_REGISTER_SIZE; break; /* STMIB (STMFA): Increment before. */ case 3: record_buf_mem[1] = (uint32_t) u_regval + ARM_INT_REGISTER_SIZE; break; default: gdb_assert_not_reached ("no decoding pattern found"); break; } record_buf_mem[0] = register_count * ARM_INT_REGISTER_SIZE; arm_insn_r->mem_rec_count = 1; /* If wback is true, also save the base register, which is going to be written to. */ if (wback) record_buf[arm_insn_r->reg_rec_count++] = reg_base; } REG_ALLOC (arm_insn_r->arm_regs, arm_insn_r->reg_rec_count, record_buf); MEM_ALLOC (arm_insn_r->arm_mems, arm_insn_r->mem_rec_count, record_buf_mem); return 0; } /* Handling opcode 101 insns. */ static int arm_record_b_bl (arm_insn_decode_record *arm_insn_r) { uint32_t record_buf[8]; /* Handle B, BL, BLX(1) insns. */ /* B simply branches so we do nothing here. */ /* Note: BLX(1) doesnt fall here but instead it falls into extension space. */ if (bit (arm_insn_r->arm_insn, 24)) { record_buf[0] = ARM_LR_REGNUM; arm_insn_r->reg_rec_count = 1; } REG_ALLOC (arm_insn_r->arm_regs, arm_insn_r->reg_rec_count, record_buf); return 0; } static int arm_record_unsupported_insn (arm_insn_decode_record *arm_insn_r) { gdb_printf (gdb_stderr, _("Process record does not support instruction " "0x%0x at address %s.\n"),arm_insn_r->arm_insn, paddress (arm_insn_r->gdbarch, arm_insn_r->this_addr)); return -1; } /* Record handler for vector data transfer instructions. */ static int arm_record_vdata_transfer_insn (arm_insn_decode_record *arm_insn_r) { uint32_t bits_a, bit_c, bit_l, reg_t, reg_v; uint32_t record_buf[4]; reg_t = bits (arm_insn_r->arm_insn, 12, 15); reg_v = bits (arm_insn_r->arm_insn, 21, 23); bits_a = bits (arm_insn_r->arm_insn, 21, 23); bit_l = bit (arm_insn_r->arm_insn, 20); bit_c = bit (arm_insn_r->arm_insn, 8); /* Handle VMOV instruction. */ if (bit_l && bit_c) { record_buf[0] = reg_t; arm_insn_r->reg_rec_count = 1; } else if (bit_l && !bit_c) { /* Handle VMOV instruction. */ if (bits_a == 0x00) { record_buf[0] = reg_t; arm_insn_r->reg_rec_count = 1; } /* Handle VMRS instruction. */ else if (bits_a == 0x07) { if (reg_t == 15) reg_t = ARM_PS_REGNUM; record_buf[0] = reg_t; arm_insn_r->reg_rec_count = 1; } } else if (!bit_l && !bit_c) { /* Handle VMOV instruction. */ if (bits_a == 0x00) { record_buf[0] = ARM_D0_REGNUM + reg_v; arm_insn_r->reg_rec_count = 1; } /* Handle VMSR instruction. */ else if (bits_a == 0x07) { record_buf[0] = ARM_FPSCR_REGNUM; arm_insn_r->reg_rec_count = 1; } } else if (!bit_l && bit_c) { /* Handle VMOV instruction. */ if (!(bits_a & 0x04)) { record_buf[0] = (reg_v | (bit (arm_insn_r->arm_insn, 7) << 4)) + ARM_D0_REGNUM; arm_insn_r->reg_rec_count = 1; } /* Handle VDUP instruction. */ else { if (bit (arm_insn_r->arm_insn, 21)) { reg_v = reg_v | (bit (arm_insn_r->arm_insn, 7) << 4); record_buf[0] = reg_v + ARM_D0_REGNUM; record_buf[1] = reg_v + ARM_D0_REGNUM + 1; arm_insn_r->reg_rec_count = 2; } else { reg_v = reg_v | (bit (arm_insn_r->arm_insn, 7) << 4); record_buf[0] = reg_v + ARM_D0_REGNUM; arm_insn_r->reg_rec_count = 1; } } } REG_ALLOC (arm_insn_r->arm_regs, arm_insn_r->reg_rec_count, record_buf); return 0; } /* Record handler for extension register load/store instructions. */ static int arm_record_exreg_ld_st_insn (arm_insn_decode_record *arm_insn_r) { uint32_t opcode, single_reg; uint8_t op_vldm_vstm; uint32_t record_buf[8], record_buf_mem[128]; ULONGEST u_regval = 0; struct regcache *reg_cache = arm_insn_r->regcache; opcode = bits (arm_insn_r->arm_insn, 20, 24); single_reg = !bit (arm_insn_r->arm_insn, 8); op_vldm_vstm = opcode & 0x1b; /* Handle VMOV instructions. */ if ((opcode & 0x1e) == 0x04) { if (bit (arm_insn_r->arm_insn, 20)) /* to_arm_registers bit 20? */ { record_buf[0] = bits (arm_insn_r->arm_insn, 12, 15); record_buf[1] = bits (arm_insn_r->arm_insn, 16, 19); arm_insn_r->reg_rec_count = 2; } else { uint8_t reg_m = bits (arm_insn_r->arm_insn, 0, 3); uint8_t bit_m = bit (arm_insn_r->arm_insn, 5); if (single_reg) { /* The first S register number m is REG_M:M (M is bit 5), the corresponding D register number is REG_M:M / 2, which is REG_M. */ record_buf[arm_insn_r->reg_rec_count++] = ARM_D0_REGNUM + reg_m; /* The second S register number is REG_M:M + 1, the corresponding D register number is (REG_M:M + 1) / 2. IOW, if bit M is 1, the first and second S registers are mapped to different D registers, otherwise, they are in the same D register. */ if (bit_m) { record_buf[arm_insn_r->reg_rec_count++] = ARM_D0_REGNUM + reg_m + 1; } } else { record_buf[0] = ((bit_m << 4) + reg_m + ARM_D0_REGNUM); arm_insn_r->reg_rec_count = 1; } } } /* Handle VSTM and VPUSH instructions. */ else if (op_vldm_vstm == 0x08 || op_vldm_vstm == 0x0a || op_vldm_vstm == 0x12) { uint32_t start_address, reg_rn, imm_off32, imm_off8, memory_count; uint32_t memory_index = 0; reg_rn = bits (arm_insn_r->arm_insn, 16, 19); regcache_raw_read_unsigned (reg_cache, reg_rn, &u_regval); imm_off8 = bits (arm_insn_r->arm_insn, 0, 7); imm_off32 = imm_off8 << 2; memory_count = imm_off8; if (bit (arm_insn_r->arm_insn, 23)) start_address = u_regval; else start_address = u_regval - imm_off32; if (bit (arm_insn_r->arm_insn, 21)) { record_buf[0] = reg_rn; arm_insn_r->reg_rec_count = 1; } while (memory_count > 0) { if (single_reg) { record_buf_mem[memory_index] = 4; record_buf_mem[memory_index + 1] = start_address; start_address = start_address + 4; memory_index = memory_index + 2; } else { record_buf_mem[memory_index] = 4; record_buf_mem[memory_index + 1] = start_address; record_buf_mem[memory_index + 2] = 4; record_buf_mem[memory_index + 3] = start_address + 4; start_address = start_address + 8; memory_index = memory_index + 4; } memory_count--; } arm_insn_r->mem_rec_count = (memory_index >> 1); } /* Handle VLDM instructions. */ else if (op_vldm_vstm == 0x09 || op_vldm_vstm == 0x0b || op_vldm_vstm == 0x13) { uint32_t reg_count, reg_vd; uint32_t reg_index = 0; uint32_t bit_d = bit (arm_insn_r->arm_insn, 22); reg_vd = bits (arm_insn_r->arm_insn, 12, 15); reg_count = bits (arm_insn_r->arm_insn, 0, 7); /* REG_VD is the first D register number. If the instruction loads memory to S registers (SINGLE_REG is TRUE), the register number is (REG_VD << 1 | bit D), so the corresponding D register number is (REG_VD << 1 | bit D) / 2 = REG_VD. */ if (!single_reg) reg_vd = reg_vd | (bit_d << 4); if (bit (arm_insn_r->arm_insn, 21) /* write back */) record_buf[reg_index++] = bits (arm_insn_r->arm_insn, 16, 19); /* If the instruction loads memory to D register, REG_COUNT should be divided by 2, according to the ARM Architecture Reference Manual. If the instruction loads memory to S register, divide by 2 as well because two S registers are mapped to D register. */ reg_count = reg_count / 2; if (single_reg && bit_d) { /* Increase the register count if S register list starts from an odd number (bit d is one). */ reg_count++; } while (reg_count > 0) { record_buf[reg_index++] = ARM_D0_REGNUM + reg_vd + reg_count - 1; reg_count--; } arm_insn_r->reg_rec_count = reg_index; } /* VSTR Vector store register. */ else if ((opcode & 0x13) == 0x10) { uint32_t start_address, reg_rn, imm_off32, imm_off8; uint32_t memory_index = 0; reg_rn = bits (arm_insn_r->arm_insn, 16, 19); regcache_raw_read_unsigned (reg_cache, reg_rn, &u_regval); imm_off8 = bits (arm_insn_r->arm_insn, 0, 7); imm_off32 = imm_off8 << 2; if (bit (arm_insn_r->arm_insn, 23)) start_address = u_regval + imm_off32; else start_address = u_regval - imm_off32; if (single_reg) { record_buf_mem[memory_index] = 4; record_buf_mem[memory_index + 1] = start_address; arm_insn_r->mem_rec_count = 1; } else { record_buf_mem[memory_index] = 4; record_buf_mem[memory_index + 1] = start_address; record_buf_mem[memory_index + 2] = 4; record_buf_mem[memory_index + 3] = start_address + 4; arm_insn_r->mem_rec_count = 2; } } /* VLDR Vector load register. */ else if ((opcode & 0x13) == 0x11) { uint32_t reg_vd = bits (arm_insn_r->arm_insn, 12, 15); if (!single_reg) { reg_vd = reg_vd | (bit (arm_insn_r->arm_insn, 22) << 4); record_buf[0] = ARM_D0_REGNUM + reg_vd; } else { reg_vd = (reg_vd << 1) | bit (arm_insn_r->arm_insn, 22); /* Record register D rather than pseudo register S. */ record_buf[0] = ARM_D0_REGNUM + reg_vd / 2; } arm_insn_r->reg_rec_count = 1; } REG_ALLOC (arm_insn_r->arm_regs, arm_insn_r->reg_rec_count, record_buf); MEM_ALLOC (arm_insn_r->arm_mems, arm_insn_r->mem_rec_count, record_buf_mem); return 0; } /* Record handler for arm/thumb mode VFP data processing instructions. */ static int arm_record_vfp_data_proc_insn (arm_insn_decode_record *arm_insn_r) { uint32_t opc1, opc2, opc3, dp_op_sz, bit_d, reg_vd; uint32_t record_buf[4]; enum insn_types {INSN_T0, INSN_T1, INSN_T2, INSN_T3, INSN_INV}; enum insn_types curr_insn_type = INSN_INV; reg_vd = bits (arm_insn_r->arm_insn, 12, 15); opc1 = bits (arm_insn_r->arm_insn, 20, 23); opc2 = bits (arm_insn_r->arm_insn, 16, 19); opc3 = bits (arm_insn_r->arm_insn, 6, 7); dp_op_sz = bit (arm_insn_r->arm_insn, 8); bit_d = bit (arm_insn_r->arm_insn, 22); /* Mask off the "D" bit. */ opc1 = opc1 & ~0x04; /* Handle VMLA, VMLS. */ if (opc1 == 0x00) { if (bit (arm_insn_r->arm_insn, 10)) { if (bit (arm_insn_r->arm_insn, 6)) curr_insn_type = INSN_T0; else curr_insn_type = INSN_T1; } else { if (dp_op_sz) curr_insn_type = INSN_T1; else curr_insn_type = INSN_T2; } } /* Handle VNMLA, VNMLS, VNMUL. */ else if (opc1 == 0x01) { if (dp_op_sz) curr_insn_type = INSN_T1; else curr_insn_type = INSN_T2; } /* Handle VMUL. */ else if (opc1 == 0x02 && !(opc3 & 0x01)) { if (bit (arm_insn_r->arm_insn, 10)) { if (bit (arm_insn_r->arm_insn, 6)) curr_insn_type = INSN_T0; else curr_insn_type = INSN_T1; } else { if (dp_op_sz) curr_insn_type = INSN_T1; else curr_insn_type = INSN_T2; } } /* Handle VADD, VSUB. */ else if (opc1 == 0x03) { if (!bit (arm_insn_r->arm_insn, 9)) { if (bit (arm_insn_r->arm_insn, 6)) curr_insn_type = INSN_T0; else curr_insn_type = INSN_T1; } else { if (dp_op_sz) curr_insn_type = INSN_T1; else curr_insn_type = INSN_T2; } } /* Handle VDIV. */ else if (opc1 == 0x08) { if (dp_op_sz) curr_insn_type = INSN_T1; else curr_insn_type = INSN_T2; } /* Handle all other vfp data processing instructions. */ else if (opc1 == 0x0b) { /* Handle VMOV. */ if (!(opc3 & 0x01) || (opc2 == 0x00 && opc3 == 0x01)) { if (bit (arm_insn_r->arm_insn, 4)) { if (bit (arm_insn_r->arm_insn, 6)) curr_insn_type = INSN_T0; else curr_insn_type = INSN_T1; } else { if (dp_op_sz) curr_insn_type = INSN_T1; else curr_insn_type = INSN_T2; } } /* Handle VNEG and VABS. */ else if ((opc2 == 0x01 && opc3 == 0x01) || (opc2 == 0x00 && opc3 == 0x03)) { if (!bit (arm_insn_r->arm_insn, 11)) { if (bit (arm_insn_r->arm_insn, 6)) curr_insn_type = INSN_T0; else curr_insn_type = INSN_T1; } else { if (dp_op_sz) curr_insn_type = INSN_T1; else curr_insn_type = INSN_T2; } } /* Handle VSQRT. */ else if (opc2 == 0x01 && opc3 == 0x03) { if (dp_op_sz) curr_insn_type = INSN_T1; else curr_insn_type = INSN_T2; } /* Handle VCVT. */ else if (opc2 == 0x07 && opc3 == 0x03) { if (!dp_op_sz) curr_insn_type = INSN_T1; else curr_insn_type = INSN_T2; } else if (opc3 & 0x01) { /* Handle VCVT. */ if ((opc2 == 0x08) || (opc2 & 0x0e) == 0x0c) { if (!bit (arm_insn_r->arm_insn, 18)) curr_insn_type = INSN_T2; else { if (dp_op_sz) curr_insn_type = INSN_T1; else curr_insn_type = INSN_T2; } } /* Handle VCVT. */ else if ((opc2 & 0x0e) == 0x0a || (opc2 & 0x0e) == 0x0e) { if (dp_op_sz) curr_insn_type = INSN_T1; else curr_insn_type = INSN_T2; } /* Handle VCVTB, VCVTT. */ else if ((opc2 & 0x0e) == 0x02) curr_insn_type = INSN_T2; /* Handle VCMP, VCMPE. */ else if ((opc2 & 0x0e) == 0x04) curr_insn_type = INSN_T3; } } switch (curr_insn_type) { case INSN_T0: reg_vd = reg_vd | (bit_d << 4); record_buf[0] = reg_vd + ARM_D0_REGNUM; record_buf[1] = reg_vd + ARM_D0_REGNUM + 1; arm_insn_r->reg_rec_count = 2; break; case INSN_T1: reg_vd = reg_vd | (bit_d << 4); record_buf[0] = reg_vd + ARM_D0_REGNUM; arm_insn_r->reg_rec_count = 1; break; case INSN_T2: reg_vd = (reg_vd << 1) | bit_d; record_buf[0] = reg_vd + ARM_D0_REGNUM; arm_insn_r->reg_rec_count = 1; break; case INSN_T3: record_buf[0] = ARM_FPSCR_REGNUM; arm_insn_r->reg_rec_count = 1; break; default: gdb_assert_not_reached ("no decoding pattern found"); break; } REG_ALLOC (arm_insn_r->arm_regs, arm_insn_r->reg_rec_count, record_buf); return 0; } /* Handling opcode 110 insns. */ static int arm_record_asimd_vfp_coproc (arm_insn_decode_record *arm_insn_r) { uint32_t op1, op1_ebit, coproc; coproc = bits (arm_insn_r->arm_insn, 8, 11); op1 = bits (arm_insn_r->arm_insn, 20, 25); op1_ebit = bit (arm_insn_r->arm_insn, 20); if ((coproc & 0x0e) == 0x0a) { /* Handle extension register ld/st instructions. */ if (!(op1 & 0x20)) return arm_record_exreg_ld_st_insn (arm_insn_r); /* 64-bit transfers between arm core and extension registers. */ if ((op1 & 0x3e) == 0x04) return arm_record_exreg_ld_st_insn (arm_insn_r); } else { /* Handle coprocessor ld/st instructions. */ if (!(op1 & 0x3a)) { /* Store. */ if (!op1_ebit) return arm_record_unsupported_insn (arm_insn_r); else /* Load. */ return arm_record_unsupported_insn (arm_insn_r); } /* Move to coprocessor from two arm core registers. */ if (op1 == 0x4) return arm_record_unsupported_insn (arm_insn_r); /* Move to two arm core registers from coprocessor. */ if (op1 == 0x5) { uint32_t reg_t[2]; reg_t[0] = bits (arm_insn_r->arm_insn, 12, 15); reg_t[1] = bits (arm_insn_r->arm_insn, 16, 19); arm_insn_r->reg_rec_count = 2; REG_ALLOC (arm_insn_r->arm_regs, arm_insn_r->reg_rec_count, reg_t); return 0; } } return arm_record_unsupported_insn (arm_insn_r); } /* Handling opcode 111 insns. */ static int arm_record_coproc_data_proc (arm_insn_decode_record *arm_insn_r) { uint32_t op, op1_ebit, coproc, bits_24_25; arm_gdbarch_tdep *tdep = gdbarch_tdep (arm_insn_r->gdbarch); struct regcache *reg_cache = arm_insn_r->regcache; arm_insn_r->opcode = bits (arm_insn_r->arm_insn, 24, 27); coproc = bits (arm_insn_r->arm_insn, 8, 11); op1_ebit = bit (arm_insn_r->arm_insn, 20); op = bit (arm_insn_r->arm_insn, 4); bits_24_25 = bits (arm_insn_r->arm_insn, 24, 25); /* Handle arm SWI/SVC system call instructions. */ if (bits_24_25 == 0x3) { if (tdep->arm_syscall_record != NULL) { ULONGEST svc_operand, svc_number; svc_operand = (0x00ffffff & arm_insn_r->arm_insn); if (svc_operand) /* OABI. */ svc_number = svc_operand - 0x900000; else /* EABI. */ regcache_raw_read_unsigned (reg_cache, 7, &svc_number); return tdep->arm_syscall_record (reg_cache, svc_number); } else { gdb_printf (gdb_stderr, _("no syscall record support\n")); return -1; } } else if (bits_24_25 == 0x02) { if (op) { if ((coproc & 0x0e) == 0x0a) { /* 8, 16, and 32-bit transfer */ return arm_record_vdata_transfer_insn (arm_insn_r); } else { if (op1_ebit) { /* MRC, MRC2 */ uint32_t record_buf[1]; record_buf[0] = bits (arm_insn_r->arm_insn, 12, 15); if (record_buf[0] == 15) record_buf[0] = ARM_PS_REGNUM; arm_insn_r->reg_rec_count = 1; REG_ALLOC (arm_insn_r->arm_regs, arm_insn_r->reg_rec_count, record_buf); return 0; } else { /* MCR, MCR2 */ return -1; } } } else { if ((coproc & 0x0e) == 0x0a) { /* VFP data-processing instructions. */ return arm_record_vfp_data_proc_insn (arm_insn_r); } else { /* CDP, CDP2 */ return -1; } } } else { unsigned int op1 = bits (arm_insn_r->arm_insn, 20, 25); if (op1 == 5) { if ((coproc & 0x0e) != 0x0a) { /* MRRC, MRRC2 */ return -1; } } else if (op1 == 4 || op1 == 5) { if ((coproc & 0x0e) == 0x0a) { /* 64-bit transfers between ARM core and extension */ return -1; } else if (op1 == 4) { /* MCRR, MCRR2 */ return -1; } } else if (op1 == 0 || op1 == 1) { /* UNDEFINED */ return -1; } else { if ((coproc & 0x0e) == 0x0a) { /* Extension register load/store */ } else { /* STC, STC2, LDC, LDC2 */ } return -1; } } return -1; } /* Handling opcode 000 insns. */ static int thumb_record_shift_add_sub (arm_insn_decode_record *thumb_insn_r) { uint32_t record_buf[8]; uint32_t reg_src1 = 0; reg_src1 = bits (thumb_insn_r->arm_insn, 0, 2); record_buf[0] = ARM_PS_REGNUM; record_buf[1] = reg_src1; thumb_insn_r->reg_rec_count = 2; REG_ALLOC (thumb_insn_r->arm_regs, thumb_insn_r->reg_rec_count, record_buf); return 0; } /* Handling opcode 001 insns. */ static int thumb_record_add_sub_cmp_mov (arm_insn_decode_record *thumb_insn_r) { uint32_t record_buf[8]; uint32_t reg_src1 = 0; reg_src1 = bits (thumb_insn_r->arm_insn, 8, 10); record_buf[0] = ARM_PS_REGNUM; record_buf[1] = reg_src1; thumb_insn_r->reg_rec_count = 2; REG_ALLOC (thumb_insn_r->arm_regs, thumb_insn_r->reg_rec_count, record_buf); return 0; } /* Handling opcode 010 insns. */ static int thumb_record_ld_st_reg_offset (arm_insn_decode_record *thumb_insn_r) { struct regcache *reg_cache = thumb_insn_r->regcache; uint32_t record_buf[8], record_buf_mem[8]; uint32_t reg_src1 = 0, reg_src2 = 0; uint32_t opcode1 = 0, opcode2 = 0, opcode3 = 0; ULONGEST u_regval[2] = {0}; opcode1 = bits (thumb_insn_r->arm_insn, 10, 12); if (bit (thumb_insn_r->arm_insn, 12)) { /* Handle load/store register offset. */ uint32_t opB = bits (thumb_insn_r->arm_insn, 9, 11); if (in_inclusive_range (opB, 4U, 7U)) { /* LDR(2), LDRB(2) , LDRH(2), LDRSB, LDRSH. */ reg_src1 = bits (thumb_insn_r->arm_insn,0, 2); record_buf[0] = reg_src1; thumb_insn_r->reg_rec_count = 1; } else if (in_inclusive_range (opB, 0U, 2U)) { /* STR(2), STRB(2), STRH(2) . */ reg_src1 = bits (thumb_insn_r->arm_insn, 3, 5); reg_src2 = bits (thumb_insn_r->arm_insn, 6, 8); regcache_raw_read_unsigned (reg_cache, reg_src1, &u_regval[0]); regcache_raw_read_unsigned (reg_cache, reg_src2, &u_regval[1]); if (0 == opB) record_buf_mem[0] = 4; /* STR (2). */ else if (2 == opB) record_buf_mem[0] = 1; /* STRB (2). */ else if (1 == opB) record_buf_mem[0] = 2; /* STRH (2). */ record_buf_mem[1] = u_regval[0] + u_regval[1]; thumb_insn_r->mem_rec_count = 1; } } else if (bit (thumb_insn_r->arm_insn, 11)) { /* Handle load from literal pool. */ /* LDR(3). */ reg_src1 = bits (thumb_insn_r->arm_insn, 8, 10); record_buf[0] = reg_src1; thumb_insn_r->reg_rec_count = 1; } else if (opcode1) { /* Special data instructions and branch and exchange */ opcode2 = bits (thumb_insn_r->arm_insn, 8, 9); opcode3 = bits (thumb_insn_r->arm_insn, 0, 2); if ((3 == opcode2) && (!opcode3)) { /* Branch with exchange. */ record_buf[0] = ARM_PS_REGNUM; thumb_insn_r->reg_rec_count = 1; } else { /* Format 8; special data processing insns. */ record_buf[0] = ARM_PS_REGNUM; record_buf[1] = (bit (thumb_insn_r->arm_insn, 7) << 3 | bits (thumb_insn_r->arm_insn, 0, 2)); thumb_insn_r->reg_rec_count = 2; } } else { /* Format 5; data processing insns. */ reg_src1 = bits (thumb_insn_r->arm_insn, 0, 2); if (bit (thumb_insn_r->arm_insn, 7)) { reg_src1 = reg_src1 + 8; } record_buf[0] = ARM_PS_REGNUM; record_buf[1] = reg_src1; thumb_insn_r->reg_rec_count = 2; } REG_ALLOC (thumb_insn_r->arm_regs, thumb_insn_r->reg_rec_count, record_buf); MEM_ALLOC (thumb_insn_r->arm_mems, thumb_insn_r->mem_rec_count, record_buf_mem); return 0; } /* Handling opcode 001 insns. */ static int thumb_record_ld_st_imm_offset (arm_insn_decode_record *thumb_insn_r) { struct regcache *reg_cache = thumb_insn_r->regcache; uint32_t record_buf[8], record_buf_mem[8]; uint32_t reg_src1 = 0; uint32_t opcode = 0, immed_5 = 0; ULONGEST u_regval = 0; opcode = bits (thumb_insn_r->arm_insn, 11, 12); if (opcode) { /* LDR(1). */ reg_src1 = bits (thumb_insn_r->arm_insn, 0, 2); record_buf[0] = reg_src1; thumb_insn_r->reg_rec_count = 1; } else { /* STR(1). */ reg_src1 = bits (thumb_insn_r->arm_insn, 3, 5); immed_5 = bits (thumb_insn_r->arm_insn, 6, 10); regcache_raw_read_unsigned (reg_cache, reg_src1, &u_regval); record_buf_mem[0] = 4; record_buf_mem[1] = u_regval + (immed_5 * 4); thumb_insn_r->mem_rec_count = 1; } REG_ALLOC (thumb_insn_r->arm_regs, thumb_insn_r->reg_rec_count, record_buf); MEM_ALLOC (thumb_insn_r->arm_mems, thumb_insn_r->mem_rec_count, record_buf_mem); return 0; } /* Handling opcode 100 insns. */ static int thumb_record_ld_st_stack (arm_insn_decode_record *thumb_insn_r) { struct regcache *reg_cache = thumb_insn_r->regcache; uint32_t record_buf[8], record_buf_mem[8]; uint32_t reg_src1 = 0; uint32_t opcode = 0, immed_8 = 0, immed_5 = 0; ULONGEST u_regval = 0; opcode = bits (thumb_insn_r->arm_insn, 11, 12); if (3 == opcode) { /* LDR(4). */ reg_src1 = bits (thumb_insn_r->arm_insn, 8, 10); record_buf[0] = reg_src1; thumb_insn_r->reg_rec_count = 1; } else if (1 == opcode) { /* LDRH(1). */ reg_src1 = bits (thumb_insn_r->arm_insn, 0, 2); record_buf[0] = reg_src1; thumb_insn_r->reg_rec_count = 1; } else if (2 == opcode) { /* STR(3). */ immed_8 = bits (thumb_insn_r->arm_insn, 0, 7); regcache_raw_read_unsigned (reg_cache, ARM_SP_REGNUM, &u_regval); record_buf_mem[0] = 4; record_buf_mem[1] = u_regval + (immed_8 * 4); thumb_insn_r->mem_rec_count = 1; } else if (0 == opcode) { /* STRH(1). */ immed_5 = bits (thumb_insn_r->arm_insn, 6, 10); reg_src1 = bits (thumb_insn_r->arm_insn, 3, 5); regcache_raw_read_unsigned (reg_cache, reg_src1, &u_regval); record_buf_mem[0] = 2; record_buf_mem[1] = u_regval + (immed_5 * 2); thumb_insn_r->mem_rec_count = 1; } REG_ALLOC (thumb_insn_r->arm_regs, thumb_insn_r->reg_rec_count, record_buf); MEM_ALLOC (thumb_insn_r->arm_mems, thumb_insn_r->mem_rec_count, record_buf_mem); return 0; } /* Handling opcode 101 insns. */ static int thumb_record_misc (arm_insn_decode_record *thumb_insn_r) { struct regcache *reg_cache = thumb_insn_r->regcache; uint32_t opcode = 0; uint32_t register_bits = 0, register_count = 0; uint32_t index = 0, start_address = 0; uint32_t record_buf[24], record_buf_mem[48]; uint32_t reg_src1; ULONGEST u_regval = 0; opcode = bits (thumb_insn_r->arm_insn, 11, 12); if (opcode == 0 || opcode == 1) { /* ADR and ADD (SP plus immediate) */ reg_src1 = bits (thumb_insn_r->arm_insn, 8, 10); record_buf[0] = reg_src1; thumb_insn_r->reg_rec_count = 1; } else { /* Miscellaneous 16-bit instructions */ uint32_t opcode2 = bits (thumb_insn_r->arm_insn, 8, 11); switch (opcode2) { case 6: /* SETEND and CPS */ break; case 0: /* ADD/SUB (SP plus immediate) */ reg_src1 = bits (thumb_insn_r->arm_insn, 8, 10); record_buf[0] = ARM_SP_REGNUM; thumb_insn_r->reg_rec_count = 1; break; case 1: /* fall through */ case 3: /* fall through */ case 9: /* fall through */ case 11: /* CBNZ, CBZ */ break; case 2: /* SXTH, SXTB, UXTH, UXTB */ record_buf[0] = bits (thumb_insn_r->arm_insn, 0, 2); thumb_insn_r->reg_rec_count = 1; break; case 4: /* fall through */ case 5: /* PUSH. */ register_bits = bits (thumb_insn_r->arm_insn, 0, 7); regcache_raw_read_unsigned (reg_cache, ARM_SP_REGNUM, &u_regval); while (register_bits) { if (register_bits & 0x00000001) register_count++; register_bits = register_bits >> 1; } start_address = u_regval - \ (4 * (bit (thumb_insn_r->arm_insn, 8) + register_count)); thumb_insn_r->mem_rec_count = register_count; while (register_count) { record_buf_mem[(register_count * 2) - 1] = start_address; record_buf_mem[(register_count * 2) - 2] = 4; start_address = start_address + 4; register_count--; } record_buf[0] = ARM_SP_REGNUM; thumb_insn_r->reg_rec_count = 1; break; case 10: /* REV, REV16, REVSH */ record_buf[0] = bits (thumb_insn_r->arm_insn, 0, 2); thumb_insn_r->reg_rec_count = 1; break; case 12: /* fall through */ case 13: /* POP. */ register_bits = bits (thumb_insn_r->arm_insn, 0, 7); while (register_bits) { if (register_bits & 0x00000001) record_buf[index++] = register_count; register_bits = register_bits >> 1; register_count++; } record_buf[index++] = ARM_PS_REGNUM; record_buf[index++] = ARM_SP_REGNUM; thumb_insn_r->reg_rec_count = index; break; case 0xe: /* BKPT insn. */ /* Handle enhanced software breakpoint insn, BKPT. */ /* CPSR is changed to be executed in ARM state, disabling normal interrupts, entering abort mode. */ /* According to high vector configuration PC is set. */ /* User hits breakpoint and type reverse, in that case, we need to go back with previous CPSR and Program Counter. */ record_buf[0] = ARM_PS_REGNUM; record_buf[1] = ARM_LR_REGNUM; thumb_insn_r->reg_rec_count = 2; /* We need to save SPSR value, which is not yet done. */ gdb_printf (gdb_stderr, _("Process record does not support instruction " "0x%0x at address %s.\n"), thumb_insn_r->arm_insn, paddress (thumb_insn_r->gdbarch, thumb_insn_r->this_addr)); return -1; case 0xf: /* If-Then, and hints */ break; default: return -1; }; } REG_ALLOC (thumb_insn_r->arm_regs, thumb_insn_r->reg_rec_count, record_buf); MEM_ALLOC (thumb_insn_r->arm_mems, thumb_insn_r->mem_rec_count, record_buf_mem); return 0; } /* Handling opcode 110 insns. */ static int thumb_record_ldm_stm_swi (arm_insn_decode_record *thumb_insn_r) { arm_gdbarch_tdep *tdep = gdbarch_tdep (thumb_insn_r->gdbarch); struct regcache *reg_cache = thumb_insn_r->regcache; uint32_t ret = 0; /* function return value: -1:record failure ; 0:success */ uint32_t reg_src1 = 0; uint32_t opcode1 = 0, opcode2 = 0, register_bits = 0, register_count = 0; uint32_t index = 0, start_address = 0; uint32_t record_buf[24], record_buf_mem[48]; ULONGEST u_regval = 0; opcode1 = bits (thumb_insn_r->arm_insn, 8, 12); opcode2 = bits (thumb_insn_r->arm_insn, 11, 12); if (1 == opcode2) { /* LDMIA. */ register_bits = bits (thumb_insn_r->arm_insn, 0, 7); /* Get Rn. */ reg_src1 = bits (thumb_insn_r->arm_insn, 8, 10); while (register_bits) { if (register_bits & 0x00000001) record_buf[index++] = register_count; register_bits = register_bits >> 1; register_count++; } record_buf[index++] = reg_src1; thumb_insn_r->reg_rec_count = index; } else if (0 == opcode2) { /* It handles both STMIA. */ register_bits = bits (thumb_insn_r->arm_insn, 0, 7); /* Get Rn. */ reg_src1 = bits (thumb_insn_r->arm_insn, 8, 10); regcache_raw_read_unsigned (reg_cache, reg_src1, &u_regval); while (register_bits) { if (register_bits & 0x00000001) register_count++; register_bits = register_bits >> 1; } start_address = u_regval; thumb_insn_r->mem_rec_count = register_count; while (register_count) { record_buf_mem[(register_count * 2) - 1] = start_address; record_buf_mem[(register_count * 2) - 2] = 4; start_address = start_address + 4; register_count--; } } else if (0x1F == opcode1) { /* Handle arm syscall insn. */ if (tdep->arm_syscall_record != NULL) { regcache_raw_read_unsigned (reg_cache, 7, &u_regval); ret = tdep->arm_syscall_record (reg_cache, u_regval); } else { gdb_printf (gdb_stderr, _("no syscall record support\n")); return -1; } } /* B (1), conditional branch is automatically taken care in process_record, as PC is saved there. */ REG_ALLOC (thumb_insn_r->arm_regs, thumb_insn_r->reg_rec_count, record_buf); MEM_ALLOC (thumb_insn_r->arm_mems, thumb_insn_r->mem_rec_count, record_buf_mem); return ret; } /* Handling opcode 111 insns. */ static int thumb_record_branch (arm_insn_decode_record *thumb_insn_r) { uint32_t record_buf[8]; uint32_t bits_h = 0; bits_h = bits (thumb_insn_r->arm_insn, 11, 12); if (2 == bits_h || 3 == bits_h) { /* BL */ record_buf[0] = ARM_LR_REGNUM; thumb_insn_r->reg_rec_count = 1; } else if (1 == bits_h) { /* BLX(1). */ record_buf[0] = ARM_PS_REGNUM; record_buf[1] = ARM_LR_REGNUM; thumb_insn_r->reg_rec_count = 2; } /* B(2) is automatically taken care in process_record, as PC is saved there. */ REG_ALLOC (thumb_insn_r->arm_regs, thumb_insn_r->reg_rec_count, record_buf); return 0; } /* Handler for thumb2 load/store multiple instructions. */ static int thumb2_record_ld_st_multiple (arm_insn_decode_record *thumb2_insn_r) { struct regcache *reg_cache = thumb2_insn_r->regcache; uint32_t reg_rn, op; uint32_t register_bits = 0, register_count = 0; uint32_t index = 0, start_address = 0; uint32_t record_buf[24], record_buf_mem[48]; ULONGEST u_regval = 0; reg_rn = bits (thumb2_insn_r->arm_insn, 16, 19); op = bits (thumb2_insn_r->arm_insn, 23, 24); if (0 == op || 3 == op) { if (bit (thumb2_insn_r->arm_insn, INSN_S_L_BIT_NUM)) { /* Handle RFE instruction. */ record_buf[0] = ARM_PS_REGNUM; thumb2_insn_r->reg_rec_count = 1; } else { /* Handle SRS instruction after reading banked SP. */ return arm_record_unsupported_insn (thumb2_insn_r); } } else if (1 == op || 2 == op) { if (bit (thumb2_insn_r->arm_insn, INSN_S_L_BIT_NUM)) { /* Handle LDM/LDMIA/LDMFD and LDMDB/LDMEA instructions. */ register_bits = bits (thumb2_insn_r->arm_insn, 0, 15); while (register_bits) { if (register_bits & 0x00000001) record_buf[index++] = register_count; register_count++; register_bits = register_bits >> 1; } record_buf[index++] = reg_rn; record_buf[index++] = ARM_PS_REGNUM; thumb2_insn_r->reg_rec_count = index; } else { /* Handle STM/STMIA/STMEA and STMDB/STMFD. */ register_bits = bits (thumb2_insn_r->arm_insn, 0, 15); regcache_raw_read_unsigned (reg_cache, reg_rn, &u_regval); while (register_bits) { if (register_bits & 0x00000001) register_count++; register_bits = register_bits >> 1; } if (1 == op) { /* Start address calculation for LDMDB/LDMEA. */ start_address = u_regval; } else if (2 == op) { /* Start address calculation for LDMDB/LDMEA. */ start_address = u_regval - register_count * 4; } thumb2_insn_r->mem_rec_count = register_count; while (register_count) { record_buf_mem[register_count * 2 - 1] = start_address; record_buf_mem[register_count * 2 - 2] = 4; start_address = start_address + 4; register_count--; } record_buf[0] = reg_rn; record_buf[1] = ARM_PS_REGNUM; thumb2_insn_r->reg_rec_count = 2; } } MEM_ALLOC (thumb2_insn_r->arm_mems, thumb2_insn_r->mem_rec_count, record_buf_mem); REG_ALLOC (thumb2_insn_r->arm_regs, thumb2_insn_r->reg_rec_count, record_buf); return ARM_RECORD_SUCCESS; } /* Handler for thumb2 load/store (dual/exclusive) and table branch instructions. */ static int thumb2_record_ld_st_dual_ex_tbb (arm_insn_decode_record *thumb2_insn_r) { struct regcache *reg_cache = thumb2_insn_r->regcache; uint32_t reg_rd, reg_rn, offset_imm; uint32_t reg_dest1, reg_dest2; uint32_t address, offset_addr; uint32_t record_buf[8], record_buf_mem[8]; uint32_t op1, op2, op3; ULONGEST u_regval[2]; op1 = bits (thumb2_insn_r->arm_insn, 23, 24); op2 = bits (thumb2_insn_r->arm_insn, 20, 21); op3 = bits (thumb2_insn_r->arm_insn, 4, 7); if (bit (thumb2_insn_r->arm_insn, INSN_S_L_BIT_NUM)) { if(!(1 == op1 && 1 == op2 && (0 == op3 || 1 == op3))) { reg_dest1 = bits (thumb2_insn_r->arm_insn, 12, 15); record_buf[0] = reg_dest1; record_buf[1] = ARM_PS_REGNUM; thumb2_insn_r->reg_rec_count = 2; } if (3 == op2 || (op1 & 2) || (1 == op1 && 1 == op2 && 7 == op3)) { reg_dest2 = bits (thumb2_insn_r->arm_insn, 8, 11); record_buf[2] = reg_dest2; thumb2_insn_r->reg_rec_count = 3; } } else { reg_rn = bits (thumb2_insn_r->arm_insn, 16, 19); regcache_raw_read_unsigned (reg_cache, reg_rn, &u_regval[0]); if (0 == op1 && 0 == op2) { /* Handle STREX. */ offset_imm = bits (thumb2_insn_r->arm_insn, 0, 7); address = u_regval[0] + (offset_imm * 4); record_buf_mem[0] = 4; record_buf_mem[1] = address; thumb2_insn_r->mem_rec_count = 1; reg_rd = bits (thumb2_insn_r->arm_insn, 0, 3); record_buf[0] = reg_rd; thumb2_insn_r->reg_rec_count = 1; } else if (1 == op1 && 0 == op2) { reg_rd = bits (thumb2_insn_r->arm_insn, 0, 3); record_buf[0] = reg_rd; thumb2_insn_r->reg_rec_count = 1; address = u_regval[0]; record_buf_mem[1] = address; if (4 == op3) { /* Handle STREXB. */ record_buf_mem[0] = 1; thumb2_insn_r->mem_rec_count = 1; } else if (5 == op3) { /* Handle STREXH. */ record_buf_mem[0] = 2 ; thumb2_insn_r->mem_rec_count = 1; } else if (7 == op3) { /* Handle STREXD. */ address = u_regval[0]; record_buf_mem[0] = 4; record_buf_mem[2] = 4; record_buf_mem[3] = address + 4; thumb2_insn_r->mem_rec_count = 2; } } else { offset_imm = bits (thumb2_insn_r->arm_insn, 0, 7); if (bit (thumb2_insn_r->arm_insn, 24)) { if (bit (thumb2_insn_r->arm_insn, 23)) offset_addr = u_regval[0] + (offset_imm * 4); else offset_addr = u_regval[0] - (offset_imm * 4); address = offset_addr; } else address = u_regval[0]; record_buf_mem[0] = 4; record_buf_mem[1] = address; record_buf_mem[2] = 4; record_buf_mem[3] = address + 4; thumb2_insn_r->mem_rec_count = 2; record_buf[0] = reg_rn; thumb2_insn_r->reg_rec_count = 1; } } REG_ALLOC (thumb2_insn_r->arm_regs, thumb2_insn_r->reg_rec_count, record_buf); MEM_ALLOC (thumb2_insn_r->arm_mems, thumb2_insn_r->mem_rec_count, record_buf_mem); return ARM_RECORD_SUCCESS; } /* Handler for thumb2 data processing (shift register and modified immediate) instructions. */ static int thumb2_record_data_proc_sreg_mimm (arm_insn_decode_record *thumb2_insn_r) { uint32_t reg_rd, op; uint32_t record_buf[8]; op = bits (thumb2_insn_r->arm_insn, 21, 24); reg_rd = bits (thumb2_insn_r->arm_insn, 8, 11); if ((0 == op || 4 == op || 8 == op || 13 == op) && 15 == reg_rd) { record_buf[0] = ARM_PS_REGNUM; thumb2_insn_r->reg_rec_count = 1; } else { record_buf[0] = reg_rd; record_buf[1] = ARM_PS_REGNUM; thumb2_insn_r->reg_rec_count = 2; } REG_ALLOC (thumb2_insn_r->arm_regs, thumb2_insn_r->reg_rec_count, record_buf); return ARM_RECORD_SUCCESS; } /* Generic handler for thumb2 instructions which effect destination and PS registers. */ static int thumb2_record_ps_dest_generic (arm_insn_decode_record *thumb2_insn_r) { uint32_t reg_rd; uint32_t record_buf[8]; reg_rd = bits (thumb2_insn_r->arm_insn, 8, 11); record_buf[0] = reg_rd; record_buf[1] = ARM_PS_REGNUM; thumb2_insn_r->reg_rec_count = 2; REG_ALLOC (thumb2_insn_r->arm_regs, thumb2_insn_r->reg_rec_count, record_buf); return ARM_RECORD_SUCCESS; } /* Handler for thumb2 branch and miscellaneous control instructions. */ static int thumb2_record_branch_misc_cntrl (arm_insn_decode_record *thumb2_insn_r) { uint32_t op, op1, op2; uint32_t record_buf[8]; op = bits (thumb2_insn_r->arm_insn, 20, 26); op1 = bits (thumb2_insn_r->arm_insn, 12, 14); op2 = bits (thumb2_insn_r->arm_insn, 8, 11); /* Handle MSR insn. */ if (!(op1 & 0x2) && 0x38 == op) { if (!(op2 & 0x3)) { /* CPSR is going to be changed. */ record_buf[0] = ARM_PS_REGNUM; thumb2_insn_r->reg_rec_count = 1; } else { arm_record_unsupported_insn(thumb2_insn_r); return -1; } } else if (4 == (op1 & 0x5) || 5 == (op1 & 0x5)) { /* BLX. */ record_buf[0] = ARM_PS_REGNUM; record_buf[1] = ARM_LR_REGNUM; thumb2_insn_r->reg_rec_count = 2; } REG_ALLOC (thumb2_insn_r->arm_regs, thumb2_insn_r->reg_rec_count, record_buf); return ARM_RECORD_SUCCESS; } /* Handler for thumb2 store single data item instructions. */ static int thumb2_record_str_single_data (arm_insn_decode_record *thumb2_insn_r) { struct regcache *reg_cache = thumb2_insn_r->regcache; uint32_t reg_rn, reg_rm, offset_imm, shift_imm; uint32_t address, offset_addr; uint32_t record_buf[8], record_buf_mem[8]; uint32_t op1, op2; ULONGEST u_regval[2]; op1 = bits (thumb2_insn_r->arm_insn, 21, 23); op2 = bits (thumb2_insn_r->arm_insn, 6, 11); reg_rn = bits (thumb2_insn_r->arm_insn, 16, 19); regcache_raw_read_unsigned (reg_cache, reg_rn, &u_regval[0]); if (bit (thumb2_insn_r->arm_insn, 23)) { /* T2 encoding. */ offset_imm = bits (thumb2_insn_r->arm_insn, 0, 11); offset_addr = u_regval[0] + offset_imm; address = offset_addr; } else { /* T3 encoding. */ if ((0 == op1 || 1 == op1 || 2 == op1) && !(op2 & 0x20)) { /* Handle STRB (register). */ reg_rm = bits (thumb2_insn_r->arm_insn, 0, 3); regcache_raw_read_unsigned (reg_cache, reg_rm, &u_regval[1]); shift_imm = bits (thumb2_insn_r->arm_insn, 4, 5); offset_addr = u_regval[1] << shift_imm; address = u_regval[0] + offset_addr; } else { offset_imm = bits (thumb2_insn_r->arm_insn, 0, 7); if (bit (thumb2_insn_r->arm_insn, 10)) { if (bit (thumb2_insn_r->arm_insn, 9)) offset_addr = u_regval[0] + offset_imm; else offset_addr = u_regval[0] - offset_imm; address = offset_addr; } else address = u_regval[0]; } } switch (op1) { /* Store byte instructions. */ case 4: case 0: record_buf_mem[0] = 1; break; /* Store half word instructions. */ case 1: case 5: record_buf_mem[0] = 2; break; /* Store word instructions. */ case 2: case 6: record_buf_mem[0] = 4; break; default: gdb_assert_not_reached ("no decoding pattern found"); break; } record_buf_mem[1] = address; thumb2_insn_r->mem_rec_count = 1; record_buf[0] = reg_rn; thumb2_insn_r->reg_rec_count = 1; REG_ALLOC (thumb2_insn_r->arm_regs, thumb2_insn_r->reg_rec_count, record_buf); MEM_ALLOC (thumb2_insn_r->arm_mems, thumb2_insn_r->mem_rec_count, record_buf_mem); return ARM_RECORD_SUCCESS; } /* Handler for thumb2 load memory hints instructions. */ static int thumb2_record_ld_mem_hints (arm_insn_decode_record *thumb2_insn_r) { uint32_t record_buf[8]; uint32_t reg_rt, reg_rn; reg_rt = bits (thumb2_insn_r->arm_insn, 12, 15); reg_rn = bits (thumb2_insn_r->arm_insn, 16, 19); if (ARM_PC_REGNUM != reg_rt) { record_buf[0] = reg_rt; record_buf[1] = reg_rn; record_buf[2] = ARM_PS_REGNUM; thumb2_insn_r->reg_rec_count = 3; REG_ALLOC (thumb2_insn_r->arm_regs, thumb2_insn_r->reg_rec_count, record_buf); return ARM_RECORD_SUCCESS; } return ARM_RECORD_FAILURE; } /* Handler for thumb2 load word instructions. */ static int thumb2_record_ld_word (arm_insn_decode_record *thumb2_insn_r) { uint32_t record_buf[8]; record_buf[0] = bits (thumb2_insn_r->arm_insn, 12, 15); record_buf[1] = ARM_PS_REGNUM; thumb2_insn_r->reg_rec_count = 2; REG_ALLOC (thumb2_insn_r->arm_regs, thumb2_insn_r->reg_rec_count, record_buf); return ARM_RECORD_SUCCESS; } /* Handler for thumb2 long multiply, long multiply accumulate, and divide instructions. */ static int thumb2_record_lmul_lmla_div (arm_insn_decode_record *thumb2_insn_r) { uint32_t opcode1 = 0, opcode2 = 0; uint32_t record_buf[8]; opcode1 = bits (thumb2_insn_r->arm_insn, 20, 22); opcode2 = bits (thumb2_insn_r->arm_insn, 4, 7); if (0 == opcode1 || 2 == opcode1 || (opcode1 >= 4 && opcode1 <= 6)) { /* Handle SMULL, UMULL, SMULAL. */ /* Handle SMLAL(S), SMULL(S), UMLAL(S), UMULL(S). */ record_buf[0] = bits (thumb2_insn_r->arm_insn, 16, 19); record_buf[1] = bits (thumb2_insn_r->arm_insn, 12, 15); record_buf[2] = ARM_PS_REGNUM; thumb2_insn_r->reg_rec_count = 3; } else if (1 == opcode1 || 3 == opcode2) { /* Handle SDIV and UDIV. */ record_buf[0] = bits (thumb2_insn_r->arm_insn, 16, 19); record_buf[1] = bits (thumb2_insn_r->arm_insn, 12, 15); record_buf[2] = ARM_PS_REGNUM; thumb2_insn_r->reg_rec_count = 3; } else return ARM_RECORD_FAILURE; REG_ALLOC (thumb2_insn_r->arm_regs, thumb2_insn_r->reg_rec_count, record_buf); return ARM_RECORD_SUCCESS; } /* Record handler for thumb32 coprocessor instructions. */ static int thumb2_record_coproc_insn (arm_insn_decode_record *thumb2_insn_r) { if (bit (thumb2_insn_r->arm_insn, 25)) return arm_record_coproc_data_proc (thumb2_insn_r); else return arm_record_asimd_vfp_coproc (thumb2_insn_r); } /* Record handler for advance SIMD structure load/store instructions. */ static int thumb2_record_asimd_struct_ld_st (arm_insn_decode_record *thumb2_insn_r) { struct regcache *reg_cache = thumb2_insn_r->regcache; uint32_t l_bit, a_bit, b_bits; uint32_t record_buf[128], record_buf_mem[128]; uint32_t reg_rn, reg_vd, address, f_elem; uint32_t index_r = 0, index_e = 0, bf_regs = 0, index_m = 0, loop_t = 0; uint8_t f_ebytes; l_bit = bit (thumb2_insn_r->arm_insn, 21); a_bit = bit (thumb2_insn_r->arm_insn, 23); b_bits = bits (thumb2_insn_r->arm_insn, 8, 11); reg_rn = bits (thumb2_insn_r->arm_insn, 16, 19); reg_vd = bits (thumb2_insn_r->arm_insn, 12, 15); reg_vd = (bit (thumb2_insn_r->arm_insn, 22) << 4) | reg_vd; f_ebytes = (1 << bits (thumb2_insn_r->arm_insn, 6, 7)); f_elem = 8 / f_ebytes; if (!l_bit) { ULONGEST u_regval = 0; regcache_raw_read_unsigned (reg_cache, reg_rn, &u_regval); address = u_regval; if (!a_bit) { /* Handle VST1. */ if (b_bits == 0x02 || b_bits == 0x0a || (b_bits & 0x0e) == 0x06) { if (b_bits == 0x07) bf_regs = 1; else if (b_bits == 0x0a) bf_regs = 2; else if (b_bits == 0x06) bf_regs = 3; else if (b_bits == 0x02) bf_regs = 4; else bf_regs = 0; for (index_r = 0; index_r < bf_regs; index_r++) { for (index_e = 0; index_e < f_elem; index_e++) { record_buf_mem[index_m++] = f_ebytes; record_buf_mem[index_m++] = address; address = address + f_ebytes; thumb2_insn_r->mem_rec_count += 1; } } } /* Handle VST2. */ else if (b_bits == 0x03 || (b_bits & 0x0e) == 0x08) { if (b_bits == 0x09 || b_bits == 0x08) bf_regs = 1; else if (b_bits == 0x03) bf_regs = 2; else bf_regs = 0; for (index_r = 0; index_r < bf_regs; index_r++) for (index_e = 0; index_e < f_elem; index_e++) { for (loop_t = 0; loop_t < 2; loop_t++) { record_buf_mem[index_m++] = f_ebytes; record_buf_mem[index_m++] = address + (loop_t * f_ebytes); thumb2_insn_r->mem_rec_count += 1; } address = address + (2 * f_ebytes); } } /* Handle VST3. */ else if ((b_bits & 0x0e) == 0x04) { for (index_e = 0; index_e < f_elem; index_e++) { for (loop_t = 0; loop_t < 3; loop_t++) { record_buf_mem[index_m++] = f_ebytes; record_buf_mem[index_m++] = address + (loop_t * f_ebytes); thumb2_insn_r->mem_rec_count += 1; } address = address + (3 * f_ebytes); } } /* Handle VST4. */ else if (!(b_bits & 0x0e)) { for (index_e = 0; index_e < f_elem; index_e++) { for (loop_t = 0; loop_t < 4; loop_t++) { record_buf_mem[index_m++] = f_ebytes; record_buf_mem[index_m++] = address + (loop_t * f_ebytes); thumb2_insn_r->mem_rec_count += 1; } address = address + (4 * f_ebytes); } } } else { uint8_t bft_size = bits (thumb2_insn_r->arm_insn, 10, 11); if (bft_size == 0x00) f_ebytes = 1; else if (bft_size == 0x01) f_ebytes = 2; else if (bft_size == 0x02) f_ebytes = 4; else f_ebytes = 0; /* Handle VST1. */ if (!(b_bits & 0x0b) || b_bits == 0x08) thumb2_insn_r->mem_rec_count = 1; /* Handle VST2. */ else if ((b_bits & 0x0b) == 0x01 || b_bits == 0x09) thumb2_insn_r->mem_rec_count = 2; /* Handle VST3. */ else if ((b_bits & 0x0b) == 0x02 || b_bits == 0x0a) thumb2_insn_r->mem_rec_count = 3; /* Handle VST4. */ else if ((b_bits & 0x0b) == 0x03 || b_bits == 0x0b) thumb2_insn_r->mem_rec_count = 4; for (index_m = 0; index_m < thumb2_insn_r->mem_rec_count; index_m++) { record_buf_mem[index_m] = f_ebytes; record_buf_mem[index_m] = address + (index_m * f_ebytes); } } } else { if (!a_bit) { /* Handle VLD1. */ if (b_bits == 0x02 || b_bits == 0x0a || (b_bits & 0x0e) == 0x06) thumb2_insn_r->reg_rec_count = 1; /* Handle VLD2. */ else if (b_bits == 0x03 || (b_bits & 0x0e) == 0x08) thumb2_insn_r->reg_rec_count = 2; /* Handle VLD3. */ else if ((b_bits & 0x0e) == 0x04) thumb2_insn_r->reg_rec_count = 3; /* Handle VLD4. */ else if (!(b_bits & 0x0e)) thumb2_insn_r->reg_rec_count = 4; } else { /* Handle VLD1. */ if (!(b_bits & 0x0b) || b_bits == 0x08 || b_bits == 0x0c) thumb2_insn_r->reg_rec_count = 1; /* Handle VLD2. */ else if ((b_bits & 0x0b) == 0x01 || b_bits == 0x09 || b_bits == 0x0d) thumb2_insn_r->reg_rec_count = 2; /* Handle VLD3. */ else if ((b_bits & 0x0b) == 0x02 || b_bits == 0x0a || b_bits == 0x0e) thumb2_insn_r->reg_rec_count = 3; /* Handle VLD4. */ else if ((b_bits & 0x0b) == 0x03 || b_bits == 0x0b || b_bits == 0x0f) thumb2_insn_r->reg_rec_count = 4; for (index_r = 0; index_r < thumb2_insn_r->reg_rec_count; index_r++) record_buf[index_r] = reg_vd + ARM_D0_REGNUM + index_r; } } if (bits (thumb2_insn_r->arm_insn, 0, 3) != 15) { record_buf[index_r] = reg_rn; thumb2_insn_r->reg_rec_count += 1; } REG_ALLOC (thumb2_insn_r->arm_regs, thumb2_insn_r->reg_rec_count, record_buf); MEM_ALLOC (thumb2_insn_r->arm_mems, thumb2_insn_r->mem_rec_count, record_buf_mem); return 0; } /* Decodes thumb2 instruction type and invokes its record handler. */ static unsigned int thumb2_record_decode_insn_handler (arm_insn_decode_record *thumb2_insn_r) { uint32_t op, op1, op2; op = bit (thumb2_insn_r->arm_insn, 15); op1 = bits (thumb2_insn_r->arm_insn, 27, 28); op2 = bits (thumb2_insn_r->arm_insn, 20, 26); if (op1 == 0x01) { if (!(op2 & 0x64 )) { /* Load/store multiple instruction. */ return thumb2_record_ld_st_multiple (thumb2_insn_r); } else if ((op2 & 0x64) == 0x4) { /* Load/store (dual/exclusive) and table branch instruction. */ return thumb2_record_ld_st_dual_ex_tbb (thumb2_insn_r); } else if ((op2 & 0x60) == 0x20) { /* Data-processing (shifted register). */ return thumb2_record_data_proc_sreg_mimm (thumb2_insn_r); } else if (op2 & 0x40) { /* Co-processor instructions. */ return thumb2_record_coproc_insn (thumb2_insn_r); } } else if (op1 == 0x02) { if (op) { /* Branches and miscellaneous control instructions. */ return thumb2_record_branch_misc_cntrl (thumb2_insn_r); } else if (op2 & 0x20) { /* Data-processing (plain binary immediate) instruction. */ return thumb2_record_ps_dest_generic (thumb2_insn_r); } else { /* Data-processing (modified immediate). */ return thumb2_record_data_proc_sreg_mimm (thumb2_insn_r); } } else if (op1 == 0x03) { if (!(op2 & 0x71 )) { /* Store single data item. */ return thumb2_record_str_single_data (thumb2_insn_r); } else if (!((op2 & 0x71) ^ 0x10)) { /* Advanced SIMD or structure load/store instructions. */ return thumb2_record_asimd_struct_ld_st (thumb2_insn_r); } else if (!((op2 & 0x67) ^ 0x01)) { /* Load byte, memory hints instruction. */ return thumb2_record_ld_mem_hints (thumb2_insn_r); } else if (!((op2 & 0x67) ^ 0x03)) { /* Load halfword, memory hints instruction. */ return thumb2_record_ld_mem_hints (thumb2_insn_r); } else if (!((op2 & 0x67) ^ 0x05)) { /* Load word instruction. */ return thumb2_record_ld_word (thumb2_insn_r); } else if (!((op2 & 0x70) ^ 0x20)) { /* Data-processing (register) instruction. */ return thumb2_record_ps_dest_generic (thumb2_insn_r); } else if (!((op2 & 0x78) ^ 0x30)) { /* Multiply, multiply accumulate, abs diff instruction. */ return thumb2_record_ps_dest_generic (thumb2_insn_r); } else if (!((op2 & 0x78) ^ 0x38)) { /* Long multiply, long multiply accumulate, and divide. */ return thumb2_record_lmul_lmla_div (thumb2_insn_r); } else if (op2 & 0x40) { /* Co-processor instructions. */ return thumb2_record_coproc_insn (thumb2_insn_r); } } return -1; } namespace { /* Abstract instruction reader. */ class abstract_instruction_reader { public: /* Read one instruction of size LEN from address MEMADDR and using BYTE_ORDER endianness. */ virtual ULONGEST read (CORE_ADDR memaddr, const size_t len, enum bfd_endian byte_order) = 0; }; /* Instruction reader from real target. */ class instruction_reader : public abstract_instruction_reader { public: ULONGEST read (CORE_ADDR memaddr, const size_t len, enum bfd_endian byte_order) override { return read_code_unsigned_integer (memaddr, len, byte_order); } }; } // namespace typedef int (*sti_arm_hdl_fp_t) (arm_insn_decode_record*); /* Decode arm/thumb insn depending on condition cods and opcodes; and dispatch it. */ static int decode_insn (abstract_instruction_reader &reader, arm_insn_decode_record *arm_record, record_type_t record_type, uint32_t insn_size) { /* (Starting from numerical 0); bits 25, 26, 27 decodes type of arm instruction. */ static const sti_arm_hdl_fp_t arm_handle_insn[8] = { arm_record_data_proc_misc_ld_str, /* 000. */ arm_record_data_proc_imm, /* 001. */ arm_record_ld_st_imm_offset, /* 010. */ arm_record_ld_st_reg_offset, /* 011. */ arm_record_ld_st_multiple, /* 100. */ arm_record_b_bl, /* 101. */ arm_record_asimd_vfp_coproc, /* 110. */ arm_record_coproc_data_proc /* 111. */ }; /* (Starting from numerical 0); bits 13,14,15 decodes type of thumb instruction. */ static const sti_arm_hdl_fp_t thumb_handle_insn[8] = { \ thumb_record_shift_add_sub, /* 000. */ thumb_record_add_sub_cmp_mov, /* 001. */ thumb_record_ld_st_reg_offset, /* 010. */ thumb_record_ld_st_imm_offset, /* 011. */ thumb_record_ld_st_stack, /* 100. */ thumb_record_misc, /* 101. */ thumb_record_ldm_stm_swi, /* 110. */ thumb_record_branch /* 111. */ }; uint32_t ret = 0; /* return value: negative:failure 0:success. */ uint32_t insn_id = 0; enum bfd_endian code_endian = gdbarch_byte_order_for_code (arm_record->gdbarch); arm_record->arm_insn = reader.read (arm_record->this_addr, insn_size, code_endian); if (ARM_RECORD == record_type) { arm_record->cond = bits (arm_record->arm_insn, 28, 31); insn_id = bits (arm_record->arm_insn, 25, 27); if (arm_record->cond == 0xf) ret = arm_record_extension_space (arm_record); else { /* If this insn has fallen into extension space then we need not decode it anymore. */ ret = arm_handle_insn[insn_id] (arm_record); } if (ret != ARM_RECORD_SUCCESS) { arm_record_unsupported_insn (arm_record); ret = -1; } } else if (THUMB_RECORD == record_type) { /* As thumb does not have condition codes, we set negative. */ arm_record->cond = -1; insn_id = bits (arm_record->arm_insn, 13, 15); ret = thumb_handle_insn[insn_id] (arm_record); if (ret != ARM_RECORD_SUCCESS) { arm_record_unsupported_insn (arm_record); ret = -1; } } else if (THUMB2_RECORD == record_type) { /* As thumb does not have condition codes, we set negative. */ arm_record->cond = -1; /* Swap first half of 32bit thumb instruction with second half. */ arm_record->arm_insn = (arm_record->arm_insn >> 16) | (arm_record->arm_insn << 16); ret = thumb2_record_decode_insn_handler (arm_record); if (ret != ARM_RECORD_SUCCESS) { arm_record_unsupported_insn (arm_record); ret = -1; } } else { /* Throw assertion. */ gdb_assert_not_reached ("not a valid instruction, could not decode"); } return ret; } #if GDB_SELF_TEST namespace selftests { /* Instruction reader class for selftests. For 16-bit Thumb instructions, an array of uint16_t should be used. For 32-bit Thumb instructions and regular 32-bit Arm instructions, an array of uint32_t should be used. */ template class instruction_reader_selftest : public abstract_instruction_reader { public: template instruction_reader_selftest (const T (&insns)[SIZE]) : m_insns (insns), m_insns_size (SIZE) {} ULONGEST read (CORE_ADDR memaddr, const size_t length, enum bfd_endian byte_order) override { SELF_CHECK (length == sizeof (T)); SELF_CHECK (memaddr % sizeof (T) == 0); SELF_CHECK ((memaddr / sizeof (T)) < m_insns_size); return m_insns[memaddr / sizeof (T)]; } private: const T *m_insns; const size_t m_insns_size; }; static void arm_record_test (void) { struct gdbarch_info info; info.bfd_arch_info = bfd_scan_arch ("arm"); struct gdbarch *gdbarch = gdbarch_find_by_info (info); SELF_CHECK (gdbarch != NULL); /* 16-bit Thumb instructions. */ { arm_insn_decode_record arm_record; memset (&arm_record, 0, sizeof (arm_insn_decode_record)); arm_record.gdbarch = gdbarch; /* Use the endian-free representation of the instructions here. The test will handle endianness conversions. */ static const uint16_t insns[] = { /* db b2 uxtb r3, r3 */ 0xb2db, /* cd 58 ldr r5, [r1, r3] */ 0x58cd, }; instruction_reader_selftest reader (insns); int ret = decode_insn (reader, &arm_record, THUMB_RECORD, THUMB_INSN_SIZE_BYTES); SELF_CHECK (ret == 0); SELF_CHECK (arm_record.mem_rec_count == 0); SELF_CHECK (arm_record.reg_rec_count == 1); SELF_CHECK (arm_record.arm_regs[0] == 3); arm_record.this_addr += 2; ret = decode_insn (reader, &arm_record, THUMB_RECORD, THUMB_INSN_SIZE_BYTES); SELF_CHECK (ret == 0); SELF_CHECK (arm_record.mem_rec_count == 0); SELF_CHECK (arm_record.reg_rec_count == 1); SELF_CHECK (arm_record.arm_regs[0] == 5); } /* 32-bit Thumb-2 instructions. */ { arm_insn_decode_record arm_record; memset (&arm_record, 0, sizeof (arm_insn_decode_record)); arm_record.gdbarch = gdbarch; /* Use the endian-free representation of the instruction here. The test will handle endianness conversions. */ static const uint32_t insns[] = { /* mrc 15, 0, r7, cr13, cr0, {3} */ 0x7f70ee1d, }; instruction_reader_selftest reader (insns); int ret = decode_insn (reader, &arm_record, THUMB2_RECORD, THUMB2_INSN_SIZE_BYTES); SELF_CHECK (ret == 0); SELF_CHECK (arm_record.mem_rec_count == 0); SELF_CHECK (arm_record.reg_rec_count == 1); SELF_CHECK (arm_record.arm_regs[0] == 7); } /* 32-bit instructions. */ { arm_insn_decode_record arm_record; memset (&arm_record, 0, sizeof (arm_insn_decode_record)); arm_record.gdbarch = gdbarch; /* Use the endian-free representation of the instruction here. The test will handle endianness conversions. */ static const uint32_t insns[] = { /* mov r5, r0 */ 0xe1a05000, }; instruction_reader_selftest reader (insns); int ret = decode_insn (reader, &arm_record, ARM_RECORD, ARM_INSN_SIZE_BYTES); SELF_CHECK (ret == 0); } } /* Instruction reader from manually cooked instruction sequences. */ class test_arm_instruction_reader : public arm_instruction_reader { public: explicit test_arm_instruction_reader (gdb::array_view insns) : m_insns (insns) {} uint32_t read (CORE_ADDR memaddr, enum bfd_endian byte_order) const override { SELF_CHECK (memaddr % 4 == 0); SELF_CHECK (memaddr / 4 < m_insns.size ()); return m_insns[memaddr / 4]; } private: const gdb::array_view m_insns; }; static void arm_analyze_prologue_test () { for (bfd_endian endianness : {BFD_ENDIAN_LITTLE, BFD_ENDIAN_BIG}) { struct gdbarch_info info; info.byte_order = endianness; info.byte_order_for_code = endianness; info.bfd_arch_info = bfd_scan_arch ("arm"); struct gdbarch *gdbarch = gdbarch_find_by_info (info); SELF_CHECK (gdbarch != NULL); /* The "sub" instruction contains an immediate value rotate count of 0, which resulted in a 32-bit shift of a 32-bit value, caught by UBSan. */ const uint32_t insns[] = { 0xe92d4ff0, /* push {r4, r5, r6, r7, r8, r9, sl, fp, lr} */ 0xe1a05000, /* mov r5, r0 */ 0xe5903020, /* ldr r3, [r0, #32] */ 0xe24dd044, /* sub sp, sp, #68 ; 0x44 */ }; test_arm_instruction_reader mem_reader (insns); arm_prologue_cache cache; arm_cache_init (&cache, gdbarch); arm_analyze_prologue (gdbarch, 0, sizeof (insns) - 1, &cache, mem_reader); } } } // namespace selftests #endif /* GDB_SELF_TEST */ /* Cleans up local record registers and memory allocations. */ static void deallocate_reg_mem (arm_insn_decode_record *record) { xfree (record->arm_regs); xfree (record->arm_mems); } /* Parse the current instruction and record the values of the registers and memory that will be changed in current instruction to record_arch_list". Return -1 if something is wrong. */ int arm_process_record (struct gdbarch *gdbarch, struct regcache *regcache, CORE_ADDR insn_addr) { uint32_t no_of_rec = 0; uint32_t ret = 0; /* return value: -1:record failure ; 0:success */ ULONGEST t_bit = 0, insn_id = 0; ULONGEST u_regval = 0; arm_insn_decode_record arm_record; memset (&arm_record, 0, sizeof (arm_insn_decode_record)); arm_record.regcache = regcache; arm_record.this_addr = insn_addr; arm_record.gdbarch = gdbarch; if (record_debug > 1) { gdb_printf (gdb_stdlog, "Process record: arm_process_record " "addr = %s\n", paddress (gdbarch, arm_record.this_addr)); } instruction_reader reader; enum bfd_endian code_endian = gdbarch_byte_order_for_code (arm_record.gdbarch); arm_record.arm_insn = reader.read (arm_record.this_addr, 2, code_endian); /* Check the insn, whether it is thumb or arm one. */ t_bit = arm_psr_thumb_bit (arm_record.gdbarch); regcache_raw_read_unsigned (arm_record.regcache, ARM_PS_REGNUM, &u_regval); if (!(u_regval & t_bit)) { /* We are decoding arm insn. */ ret = decode_insn (reader, &arm_record, ARM_RECORD, ARM_INSN_SIZE_BYTES); } else { insn_id = bits (arm_record.arm_insn, 11, 15); /* is it thumb2 insn? */ if ((0x1D == insn_id) || (0x1E == insn_id) || (0x1F == insn_id)) { ret = decode_insn (reader, &arm_record, THUMB2_RECORD, THUMB2_INSN_SIZE_BYTES); } else { /* We are decoding thumb insn. */ ret = decode_insn (reader, &arm_record, THUMB_RECORD, THUMB_INSN_SIZE_BYTES); } } if (0 == ret) { /* Record registers. */ record_full_arch_list_add_reg (arm_record.regcache, ARM_PC_REGNUM); if (arm_record.arm_regs) { for (no_of_rec = 0; no_of_rec < arm_record.reg_rec_count; no_of_rec++) { if (record_full_arch_list_add_reg (arm_record.regcache , arm_record.arm_regs[no_of_rec])) ret = -1; } } /* Record memories. */ if (arm_record.arm_mems) { for (no_of_rec = 0; no_of_rec < arm_record.mem_rec_count; no_of_rec++) { if (record_full_arch_list_add_mem ((CORE_ADDR)arm_record.arm_mems[no_of_rec].addr, arm_record.arm_mems[no_of_rec].len)) ret = -1; } } if (record_full_arch_list_add_end ()) ret = -1; } deallocate_reg_mem (&arm_record); return ret; } /* See arm-tdep.h. */ const target_desc * arm_read_description (arm_fp_type fp_type, bool tls) { struct target_desc *tdesc = tdesc_arm_list[fp_type][tls]; if (tdesc == nullptr) { tdesc = arm_create_target_description (fp_type, tls); tdesc_arm_list[fp_type][tls] = tdesc; } return tdesc; } /* See arm-tdep.h. */ const target_desc * arm_read_mprofile_description (arm_m_profile_type m_type) { struct target_desc *tdesc = tdesc_arm_mprofile_list[m_type]; if (tdesc == nullptr) { tdesc = arm_create_mprofile_target_description (m_type); tdesc_arm_mprofile_list[m_type] = tdesc; } return tdesc; }