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Diffstat (limited to 'gdbserver/linux-i386-ipa.c')
| -rw-r--r-- | gdbserver/linux-i386-ipa.c | 294 |
1 files changed, 294 insertions, 0 deletions
diff --git a/gdbserver/linux-i386-ipa.c b/gdbserver/linux-i386-ipa.c new file mode 100644 index 00000000000..41f77c8deac --- /dev/null +++ b/gdbserver/linux-i386-ipa.c @@ -0,0 +1,294 @@ +/* GNU/Linux/x86 specific low level interface, for the in-process + agent library for GDB. + + Copyright (C) 2010-2020 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 <http://www.gnu.org/licenses/>. */ + +#include "server.h" +#include <sys/mman.h> +#include "tracepoint.h" +#include "linux-x86-tdesc.h" +#include "gdbsupport/x86-xstate.h" + +/* GDB register numbers. */ + +enum i386_gdb_regnum +{ + I386_EAX_REGNUM, /* %eax */ + I386_ECX_REGNUM, /* %ecx */ + I386_EDX_REGNUM, /* %edx */ + I386_EBX_REGNUM, /* %ebx */ + I386_ESP_REGNUM, /* %esp */ + I386_EBP_REGNUM, /* %ebp */ + I386_ESI_REGNUM, /* %esi */ + I386_EDI_REGNUM, /* %edi */ + I386_EIP_REGNUM, /* %eip */ + I386_EFLAGS_REGNUM, /* %eflags */ + I386_CS_REGNUM, /* %cs */ + I386_SS_REGNUM, /* %ss */ + I386_DS_REGNUM, /* %ds */ + I386_ES_REGNUM, /* %es */ + I386_FS_REGNUM, /* %fs */ + I386_GS_REGNUM, /* %gs */ + I386_ST0_REGNUM /* %st(0) */ +}; + +#define i386_num_regs 16 + +#define FT_CR_EAX 15 +#define FT_CR_ECX 14 +#define FT_CR_EDX 13 +#define FT_CR_EBX 12 +#define FT_CR_UESP 11 +#define FT_CR_EBP 10 +#define FT_CR_ESI 9 +#define FT_CR_EDI 8 +#define FT_CR_EIP 7 +#define FT_CR_EFL 6 +#define FT_CR_DS 5 +#define FT_CR_ES 4 +#define FT_CR_FS 3 +#define FT_CR_GS 2 +#define FT_CR_SS 1 +#define FT_CR_CS 0 + +/* Mapping between the general-purpose registers in jump tracepoint + format and GDB's register array layout. */ + +static const int i386_ft_collect_regmap[] = +{ + FT_CR_EAX * 4, FT_CR_ECX * 4, FT_CR_EDX * 4, FT_CR_EBX * 4, + FT_CR_UESP * 4, FT_CR_EBP * 4, FT_CR_ESI * 4, FT_CR_EDI * 4, + FT_CR_EIP * 4, FT_CR_EFL * 4, FT_CR_CS * 4, FT_CR_SS * 4, + FT_CR_DS * 4, FT_CR_ES * 4, FT_CR_FS * 4, FT_CR_GS * 4 +}; + +void +supply_fast_tracepoint_registers (struct regcache *regcache, + const unsigned char *buf) +{ + int i; + + for (i = 0; i < i386_num_regs; i++) + { + int regval; + + if (i >= I386_CS_REGNUM && i <= I386_GS_REGNUM) + regval = *(short *) (((char *) buf) + i386_ft_collect_regmap[i]); + else + regval = *(int *) (((char *) buf) + i386_ft_collect_regmap[i]); + + supply_register (regcache, i, ®val); + } +} + +ULONGEST +get_raw_reg (const unsigned char *raw_regs, int regnum) +{ + /* This should maybe be allowed to return an error code, or perhaps + better, have the emit_reg detect this, and emit a constant zero, + or something. */ + + if (regnum > i386_num_regs) + return 0; + else if (regnum >= I386_CS_REGNUM && regnum <= I386_GS_REGNUM) + return *(short *) (raw_regs + i386_ft_collect_regmap[regnum]); + else + return *(int *) (raw_regs + i386_ft_collect_regmap[regnum]); +} + +#ifdef HAVE_UST + +#include <ust/processor.h> + +/* "struct registers" is the UST object type holding the registers at + the time of the static tracepoint marker call. This doesn't + contain EIP, but we know what it must have been (the marker + address). */ + +#define ST_REGENTRY(REG) \ + { \ + offsetof (struct registers, REG), \ + sizeof (((struct registers *) NULL)->REG) \ + } + +static struct +{ + int offset; + int size; +} i386_st_collect_regmap[] = + { + ST_REGENTRY(eax), + ST_REGENTRY(ecx), + ST_REGENTRY(edx), + ST_REGENTRY(ebx), + ST_REGENTRY(esp), + ST_REGENTRY(ebp), + ST_REGENTRY(esi), + ST_REGENTRY(edi), + { -1, 0 }, /* eip */ + ST_REGENTRY(eflags), + ST_REGENTRY(cs), + ST_REGENTRY(ss), + }; + +#define i386_NUM_ST_COLLECT_GREGS \ + (sizeof (i386_st_collect_regmap) / sizeof (i386_st_collect_regmap[0])) + +void +supply_static_tracepoint_registers (struct regcache *regcache, + const unsigned char *buf, + CORE_ADDR pc) +{ + int i; + unsigned int newpc = pc; + + supply_register (regcache, I386_EIP_REGNUM, &newpc); + + for (i = 0; i < i386_NUM_ST_COLLECT_GREGS; i++) + if (i386_st_collect_regmap[i].offset != -1) + { + switch (i386_st_collect_regmap[i].size) + { + case 4: + supply_register (regcache, i, + ((char *) buf) + + i386_st_collect_regmap[i].offset); + break; + case 2: + { + unsigned long reg + = * (short *) (((char *) buf) + + i386_st_collect_regmap[i].offset); + reg &= 0xffff; + supply_register (regcache, i, ®); + } + break; + default: + internal_error (__FILE__, __LINE__, "unhandled register size: %d", + i386_st_collect_regmap[i].size); + } + } +} + +#endif /* HAVE_UST */ + + +/* This is only needed because reg-i386-linux-lib.o references it. We + may use it proper at some point. */ +const char *gdbserver_xmltarget; + +/* Attempt to allocate memory for trampolines in the first 64 KiB of + memory to enable smaller jump patches. */ + +static void +initialize_fast_tracepoint_trampoline_buffer (void) +{ + const CORE_ADDR buffer_end = 64 * 1024; + /* Ensure that the buffer will be at least 1 KiB in size, which is + enough space for over 200 fast tracepoints. */ + const int min_buffer_size = 1024; + char buf[IPA_BUFSIZ]; + CORE_ADDR mmap_min_addr = buffer_end + 1; + ULONGEST buffer_size; + FILE *f = fopen ("/proc/sys/vm/mmap_min_addr", "r"); + + if (!f) + { + snprintf (buf, sizeof (buf), "mmap_min_addr open failed: %s", + safe_strerror (errno)); + set_trampoline_buffer_space (0, 0, buf); + return; + } + + if (fgets (buf, IPA_BUFSIZ, f)) + sscanf (buf, "%llu", &mmap_min_addr); + + fclose (f); + + buffer_size = buffer_end - mmap_min_addr; + + if (buffer_size >= min_buffer_size) + { + if (mmap ((void *) (uintptr_t) mmap_min_addr, buffer_size, + PROT_READ | PROT_EXEC | PROT_WRITE, + MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, + -1, 0) + != MAP_FAILED) + set_trampoline_buffer_space (mmap_min_addr, buffer_end, NULL); + else + { + snprintf (buf, IPA_BUFSIZ, "low-64K-buffer mmap() failed: %s", + safe_strerror (errno)); + set_trampoline_buffer_space (0, 0, buf); + } + } + else + { + snprintf (buf, IPA_BUFSIZ, "mmap_min_addr is %d, must be %d or less", + (int) mmap_min_addr, (int) buffer_end - min_buffer_size); + set_trampoline_buffer_space (0, 0, buf); + } +} + +/* Map the tdesc index to xcr0 mask. */ +static uint64_t idx2mask[X86_TDESC_LAST] = { + X86_XSTATE_X87_MASK, + X86_XSTATE_SSE_MASK, + X86_XSTATE_AVX_MASK, + X86_XSTATE_MPX_MASK, + X86_XSTATE_AVX_MPX_MASK, + X86_XSTATE_AVX_AVX512_MASK, + X86_XSTATE_AVX_MPX_AVX512_PKU_MASK, +}; + +/* Return target_desc to use for IPA, given the tdesc index passed by + gdbserver. */ + +const struct target_desc * +get_ipa_tdesc (int idx) +{ + if (idx >= X86_TDESC_LAST) + { + internal_error (__FILE__, __LINE__, + "unknown ipa tdesc index: %d", idx); + } + return i386_linux_read_description (idx2mask[idx]); +} + +/* Allocate buffer for the jump pads. On i386, we can reach an arbitrary + address with a jump instruction, so just allocate normally. */ + +void * +alloc_jump_pad_buffer (size_t size) +{ + void *res = mmap (NULL, size, PROT_READ | PROT_WRITE | PROT_EXEC, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + + if (res == MAP_FAILED) + return NULL; + + return res; +} + +void +initialize_low_tracepoint (void) +{ + initialize_fast_tracepoint_trampoline_buffer (); + for (auto i = 0; i < X86_TDESC_LAST; i++) + i386_linux_read_description (idx2mask[i]); +} |