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Diffstat (limited to 'sysdeps/m68k/dl-machine.h')
| -rw-r--r-- | sysdeps/m68k/dl-machine.h | 316 |
1 files changed, 316 insertions, 0 deletions
diff --git a/sysdeps/m68k/dl-machine.h b/sysdeps/m68k/dl-machine.h new file mode 100644 index 0000000000..146c5866a9 --- /dev/null +++ b/sysdeps/m68k/dl-machine.h @@ -0,0 +1,316 @@ +/* Machine-dependent ELF dynamic relocation inline functions. m68k version. + Copyright (C) 1996-2001, 2002, 2003, 2004 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#ifndef dl_machine_h +#define dl_machine_h + +#define ELF_MACHINE_NAME "m68k" + +#include <sys/param.h> + +/* Return nonzero iff ELF header is compatible with the running host. */ +static inline int +elf_machine_matches_host (const Elf32_Ehdr *ehdr) +{ + return ehdr->e_machine == EM_68K; +} + + +/* Return the link-time address of _DYNAMIC. Conveniently, this is the + first element of the GOT. This must be inlined in a function which + uses global data. */ +static inline Elf32_Addr +elf_machine_dynamic (void) +{ + register Elf32_Addr *got asm ("%a5"); + return *got; +} + + +/* Return the run-time load address of the shared object. */ +static inline Elf32_Addr +elf_machine_load_address (void) +{ + Elf32_Addr addr; + asm ("lea _dl_start(%%pc), %0\n\t" + "sub.l _dl_start@GOT.w(%%a5), %0" + : "=a" (addr)); + return addr; +} + + +/* Set up the loaded object described by L so its unrelocated PLT + entries will jump to the on-demand fixup code in dl-runtime.c. */ + +static inline int __attribute__ ((always_inline)) +elf_machine_runtime_setup (struct link_map *l, int lazy, int profile) +{ + Elf32_Addr *got; + extern void _dl_runtime_resolve (Elf32_Word); + extern void _dl_runtime_profile (Elf32_Word); + + if (l->l_info[DT_JMPREL] && lazy) + { + /* The GOT entries for functions in the PLT have not yet been + filled in. Their initial contents will arrange when called + to push an offset into the .rela.plt section, push + _GLOBAL_OFFSET_TABLE_[1], and then jump to + _GLOBAL_OFFSET_TABLE_[2]. */ + got = (Elf32_Addr *) D_PTR (l, l_info[DT_PLTGOT]); + got[1] = (Elf32_Addr) l; /* Identify this shared object. */ + + /* The got[2] entry contains the address of a function which gets + called to get the address of a so far unresolved function and + jump to it. The profiling extension of the dynamic linker allows + to intercept the calls to collect information. In this case we + don't store the address in the GOT so that all future calls also + end in this function. */ + if (profile) + { + got[2] = (Elf32_Addr) &_dl_runtime_profile; + + if (_dl_name_match_p (GLRO(dl_profile), l)) + { + /* This is the object we are looking for. Say that we really + want profiling and the timers are started. */ + GL(dl_profile_map) = l; + } + } + else + /* This function will get called to fix up the GOT entry indicated by + the offset on the stack, and then jump to the resolved address. */ + got[2] = (Elf32_Addr) &_dl_runtime_resolve; + } + + return lazy; +} + +/* This code is used in dl-runtime.c to call the `fixup' function + and then redirect to the address it returns. */ +#define TRAMPOLINE_TEMPLATE(tramp_name, fixup_name) \ +"| Trampoline for " #fixup_name "\n\ + .globl " #tramp_name "\n\ + .type " #tramp_name ", @function\n\ +" #tramp_name ":\n\ + | Save %a0 (struct return address) and %a1.\n\ + move.l %a0, -(%sp)\n\ + move.l %a1, -(%sp)\n\ + | Call the real address resolver.\n\ + jbsr " #fixup_name "\n\ + | Restore register %a0 and %a1.\n\ + move.l (%sp)+, %a1\n\ + move.l (%sp)+, %a0\n\ + | Pop parameters\n\ + addq.l #8, %sp\n\ + | Call real function.\n\ + jmp (%d0)\n\ + .size " #tramp_name ", . - " #tramp_name "\n" +#ifndef PROF +#define ELF_MACHINE_RUNTIME_TRAMPOLINE \ +asm (TRAMPOLINE_TEMPLATE (_dl_runtime_resolve, fixup) \ + TRAMPOLINE_TEMPLATE (_dl_runtime_profile, profile_fixup)); +#else +#define ELF_MACHINE_RUNTIME_TRAMPOLINE \ +asm (TRAMPOLINE_TEMPLATE (_dl_runtime_resolve, fixup) \ + ".globl _dl_runtime_profile\n" \ + ".set _dl_runtime_profile, _dl_runtime_resolve"); +#endif +#define ELF_MACHINE_RUNTIME_FIXUP_ARGS long int save_a0, long int save_a1 + + +/* Mask identifying addresses reserved for the user program, + where the dynamic linker should not map anything. */ +#define ELF_MACHINE_USER_ADDRESS_MASK 0x80000000UL + +/* Initial entry point code for the dynamic linker. + The C function `_dl_start' is the real entry point; + its return value is the user program's entry point. */ + +#define RTLD_START asm ("\ + .text\n\ + .globl _start\n\ + .type _start,@function\n\ +_start:\n\ + move.l %sp, -(%sp)\n\ + jbsr _dl_start\n\ + addq.l #4, %sp\n\ + /* FALLTHRU */\n\ +\n\ + .globl _dl_start_user\n\ + .type _dl_start_user,@function\n\ +_dl_start_user:\n\ + | Save the user entry point address in %a4.\n\ + move.l %d0, %a4\n\ + | See if we were run as a command with the executable file\n\ + | name as an extra leading argument.\n\ + move.l _dl_skip_args(%pc), %d0\n\ + | Pop the original argument count\n\ + move.l (%sp)+, %d1\n\ + | Subtract _dl_skip_args from it.\n\ + sub.l %d0, %d1\n\ + | Adjust the stack pointer to skip _dl_skip_args words.\n\ + lea (%sp, %d0*4), %sp\n\ + | Push back the modified argument count.\n\ + move.l %d1, -(%sp)\n\ + # Call _dl_init (struct link_map *main_map, int argc, char **argv, char **env)\n\ + pea 8(%sp, %d1*4)\n\ + pea 8(%sp)\n\ + move.l %d1, -(%sp)\n\ + move.l _rtld_local(%pc), -(%sp)\n\ + jbsr _dl_init_internal@PLTPC\n\ + addq.l #8, %sp\n\ + addq.l #8, %sp\n\ + | Pass our finalizer function to the user in %a1.\n\ + lea _dl_fini(%pc), %a1\n\ + | Initialize %fp with the stack pointer.\n\ + move.l %sp, %fp\n\ + | Jump to the user's entry point.\n\ + jmp (%a4)\n\ + .size _dl_start_user, . - _dl_start_user\n\ + .previous"); + +/* ELF_RTYPE_CLASS_PLT iff TYPE describes relocation of a PLT entry, so + PLT entries should not be allowed to define the value. + ELF_RTYPE_CLASS_NOCOPY iff TYPE should not be allowed to resolve to one + of the main executable's symbols, as for a COPY reloc. */ +#define elf_machine_type_class(type) \ + ((((type) == R_68K_JMP_SLOT) * ELF_RTYPE_CLASS_PLT) \ + | (((type) == R_68K_COPY) * ELF_RTYPE_CLASS_COPY)) + +/* A reloc type used for ld.so cmdline arg lookups to reject PLT entries. */ +#define ELF_MACHINE_JMP_SLOT R_68K_JMP_SLOT + +/* The m68k never uses Elf32_Rel relocations. */ +#define ELF_MACHINE_NO_REL 1 + +static inline Elf32_Addr +elf_machine_fixup_plt (struct link_map *map, lookup_t t, + const Elf32_Rela *reloc, + Elf32_Addr *reloc_addr, Elf32_Addr value) +{ + return *reloc_addr = value; +} + +/* Return the final value of a plt relocation. On the m68k the JMP_SLOT + relocation ignores the addend. */ +static inline Elf32_Addr +elf_machine_plt_value (struct link_map *map, const Elf32_Rela *reloc, + Elf32_Addr value) +{ + return value; +} + +#endif /* !dl_machine_h */ + +#ifdef RESOLVE + +/* Perform the relocation specified by RELOC and SYM (which is fully resolved). + MAP is the object containing the reloc. */ + +auto inline void __attribute__ ((unused, always_inline)) +elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc, + const Elf32_Sym *sym, const struct r_found_version *version, + void *const reloc_addr_arg) +{ + Elf32_Addr *const reloc_addr = reloc_addr_arg; + const unsigned int r_type = ELF32_R_TYPE (reloc->r_info); + + if (__builtin_expect (r_type == R_68K_RELATIVE, 0)) + *reloc_addr = map->l_addr + reloc->r_addend; + else + { + const Elf32_Sym *const refsym = sym; + Elf32_Addr value = RESOLVE (&sym, version, r_type); + if (sym) + value += sym->st_value; + + switch (r_type) + { + case R_68K_COPY: + if (sym == NULL) + /* This can happen in trace mode if an object could not be + found. */ + break; + if (sym->st_size > refsym->st_size + || (sym->st_size < refsym->st_size && GLRO(dl_verbose))) + { + const char *strtab; + + strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]); + _dl_error_printf ("\ +%s: Symbol `%s' has different size in shared object, consider re-linking\n", + rtld_progname ?: "<program name unknown>", + strtab + refsym->st_name); + } + memcpy (reloc_addr_arg, (void *) value, + MIN (sym->st_size, refsym->st_size)); + break; + case R_68K_GLOB_DAT: + case R_68K_JMP_SLOT: + *reloc_addr = value; + break; + case R_68K_8: + *(char *) reloc_addr = value + reloc->r_addend; + break; + case R_68K_16: + *(short *) reloc_addr = value + reloc->r_addend; + break; + case R_68K_32: + *reloc_addr = value + reloc->r_addend; + break; + case R_68K_PC8: + *(char *) reloc_addr + = value + reloc->r_addend - (Elf32_Addr) reloc_addr; + break; + case R_68K_PC16: + *(short *) reloc_addr + = value + reloc->r_addend - (Elf32_Addr) reloc_addr; + break; + case R_68K_PC32: + *reloc_addr = value + reloc->r_addend - (Elf32_Addr) reloc_addr; + break; + case R_68K_NONE: /* Alright, Wilbur. */ + break; + default: + _dl_reloc_bad_type (map, r_type, 0); + break; + } + } +} + +auto inline void __attribute__ ((unused, always_inline)) +elf_machine_rela_relative (Elf32_Addr l_addr, const Elf32_Rela *reloc, + void *const reloc_addr_arg) +{ + Elf32_Addr *const reloc_addr = reloc_addr_arg; + *reloc_addr = l_addr + reloc->r_addend; +} + +auto inline void __attribute__ ((unused, always_inline)) +elf_machine_lazy_rel (struct link_map *map, + Elf32_Addr l_addr, const Elf32_Rela *reloc) +{ + Elf32_Addr *const reloc_addr = (void *) (l_addr + reloc->r_offset); + if (ELF32_R_TYPE (reloc->r_info) == R_68K_JMP_SLOT) + *reloc_addr += l_addr; + else + _dl_reloc_bad_type (map, ELF32_R_TYPE (reloc->r_info), 1); +} + +#endif /* RESOLVE */ |