292 lines
8.3 KiB
C
292 lines
8.3 KiB
C
/* Target-dependent code for GNU/Linux running on x86-64, for GDB.
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Copyright 2001, 2003 Free Software Foundation, Inc.
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Contributed by Jiri Smid, SuSE Labs.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include "defs.h"
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#include "inferior.h"
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#include "gdbcore.h"
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#include "regcache.h"
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#include "osabi.h"
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#include "gdb_string.h"
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#include "x86-64-tdep.h"
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#include "x86-64-linux-tdep.h"
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/* Register indexes to 'struct user' come from <sys/reg.h>. */
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#define USER_R15 0
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#define USER_R14 1
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#define USER_R13 2
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#define USER_R12 3
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#define USER_RBP 4
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#define USER_RBX 5
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#define USER_R11 6
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#define USER_R10 7
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#define USER_R9 8
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#define USER_R8 9
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#define USER_RAX 10
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#define USER_RCX 11
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#define USER_RDX 12
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#define USER_RSI 13
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#define USER_RDI 14
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#define USER_RIP 16
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#define USER_CS 17
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#define USER_EFLAGS 18
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#define USER_RSP 19
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#define USER_SS 20
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#define USER_DS 23
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#define USER_ES 24
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#define USER_FS 25
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#define USER_GS 26
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/* Mapping between the general-purpose registers in `struct user'
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format and GDB's register array layout. */
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static int user_to_gdb_regmap[] =
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{
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USER_RAX, USER_RBX, USER_RCX, USER_RDX,
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USER_RSI, USER_RDI, USER_RBP, USER_RSP,
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USER_R8, USER_R9, USER_R10, USER_R11,
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USER_R12, USER_R13, USER_R14, USER_R15,
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USER_RIP, USER_EFLAGS,
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USER_DS, USER_ES, USER_FS, USER_GS
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};
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/* Fill GDB's register array with the general-purpose register values
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in *GREGSETP. */
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void
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x86_64_linux_supply_gregset (char *regp)
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{
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int i;
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for (i = 0; i < X86_64_NUM_GREGS; i++)
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supply_register (i, regp + (user_to_gdb_regmap[i] * 8));
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}
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/* Fill register REGNO (if it is a general-purpose register) in
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*GREGSETPS with the value in GDB's register array. If REGNO is -1,
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do this for all registers. */
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void
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x86_64_linux_fill_gregset (char *regp, int regno)
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{
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int i;
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for (i = 0; i < X86_64_NUM_GREGS; i++)
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if (regno == -1 || regno == i)
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regcache_collect (i, regp + (user_to_gdb_regmap[i] * 8));
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}
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/* The register sets used in GNU/Linux ELF core-dumps are identical to
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the register sets used by `ptrace'. The corresponding types are
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`elf_gregset_t' for the general-purpose registers (with
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`elf_greg_t' the type of a single GP register) and `elf_fpregset_t'
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for the floating-point registers. */
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static void
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fetch_core_registers (char *core_reg_sect, unsigned core_reg_size,
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int which, CORE_ADDR ignore)
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{
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switch (which)
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{
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case 0: /* Integer registers. */
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if (core_reg_size != 216)
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warning ("Wrong size register set in core file.");
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else
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x86_64_linux_supply_gregset (core_reg_sect);
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break;
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case 2: /* Floating point registers. */
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case 3: /* "Extended" floating point registers. This is gdb-speak
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for SSE/SSE2. */
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if (core_reg_size != 512)
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warning ("Wrong size XMM register set in core file.");
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else
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x86_64_supply_fxsave (core_reg_sect, -1);
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break;
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default:
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/* Don't know what kind of register request this is; just ignore it. */
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break;
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}
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}
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static struct core_fns x86_64_core_fns =
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{
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bfd_target_elf_flavour, /* core_flavour */
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default_check_format, /* check_format */
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default_core_sniffer, /* core_sniffer */
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fetch_core_registers, /* core_read_registers */
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NULL /* next */
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};
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#define LINUX_SIGTRAMP_INSN0 0x48 /* mov $NNNNNNNN, %rax */
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#define LINUX_SIGTRAMP_OFFSET0 0
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#define LINUX_SIGTRAMP_INSN1 0x0f /* syscall */
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#define LINUX_SIGTRAMP_OFFSET1 7
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static const unsigned char linux_sigtramp_code[] =
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{
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/* mov $__NR_rt_sigreturn, %rax */
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LINUX_SIGTRAMP_INSN0, 0xc7, 0xc0, 0x0f, 0x00, 0x00, 0x00,
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/* syscall */
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LINUX_SIGTRAMP_INSN1, 0x05
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};
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#define LINUX_SIGTRAMP_LEN (sizeof linux_sigtramp_code)
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/* If PC is in a sigtramp routine, return the address of the start of
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the routine. Otherwise, return 0. */
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static CORE_ADDR
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x86_64_linux_sigtramp_start (CORE_ADDR pc)
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{
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unsigned char buf[LINUX_SIGTRAMP_LEN];
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/* We only recognize a signal trampoline if PC is at the start of
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one of the two instructions. We optimize for finding the PC at
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the start, as will be the case when the trampoline is not the
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first frame on the stack. We assume that in the case where the
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PC is not at the start of the instruction sequence, there will be
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a few trailing readable bytes on the stack. */
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if (read_memory_nobpt (pc, (char *) buf, LINUX_SIGTRAMP_LEN) != 0)
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return 0;
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if (buf[0] != LINUX_SIGTRAMP_INSN0)
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{
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if (buf[0] != LINUX_SIGTRAMP_INSN1)
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return 0;
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pc -= LINUX_SIGTRAMP_OFFSET1;
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if (read_memory_nobpt (pc, (char *) buf, LINUX_SIGTRAMP_LEN) != 0)
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return 0;
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}
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if (memcmp (buf, linux_sigtramp_code, LINUX_SIGTRAMP_LEN) != 0)
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return 0;
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return pc;
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}
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/* Return whether PC is in a GNU/Linux sigtramp routine. */
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static int
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x86_64_linux_pc_in_sigtramp (CORE_ADDR pc, char *name)
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{
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/* If we have NAME, we can optimize the search. The trampoline is
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named __restore_rt. However, it isn't dynamically exported from
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the shared C library, so the trampoline may appear to be part of
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the preceding function. This should always be sigaction,
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__sigaction, or __libc_sigaction (all aliases to the same
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function). */
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if (name == NULL || strstr (name, "sigaction") != NULL)
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return (x86_64_linux_sigtramp_start (pc) != 0);
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return (strcmp ("__restore_rt", name) == 0);
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}
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/* Offset to struct sigcontext in ucontext, from <asm/ucontext.h>. */
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#define X86_64_LINUX_UCONTEXT_SIGCONTEXT_OFFSET 40
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/* Assuming NEXT_FRAME is a frame following a GNU/Linux sigtramp
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routine, return the address of the associated sigcontext structure. */
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static CORE_ADDR
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x86_64_linux_sigcontext_addr (struct frame_info *next_frame)
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{
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CORE_ADDR sp;
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char buf[8];
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frame_unwind_register (next_frame, SP_REGNUM, buf);
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sp = extract_unsigned_integer (buf, 8);
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/* The sigcontext structure is part of the user context. A pointer
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to the user context is passed as the third argument to the signal
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handler, i.e. in %rdx. Unfortunately %rdx isn't preserved across
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function calls so we can't use it. Fortunately the user context
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is part of the signal frame and the unwound %rsp directly points
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at it. */
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return sp + X86_64_LINUX_UCONTEXT_SIGCONTEXT_OFFSET;
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}
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/* From <asm/sigcontext.h>. */
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static int x86_64_linux_sc_reg_offset[X86_64_NUM_GREGS] =
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{
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13 * 8, /* %rax */
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11 * 8, /* %rbx */
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14 * 8, /* %rcx */
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12 * 8, /* %rdx */
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9 * 8, /* %rsi */
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8 * 8, /* %rdi */
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10 * 8, /* %rbp */
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15 * 8, /* %rsp */
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0 * 8, /* %r8 */
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1 * 8, /* %r9 */
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2 * 8, /* %r10 */
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3 * 8, /* %r11 */
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4 * 8, /* %r12 */
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5 * 8, /* %r13 */
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6 * 8, /* %r14 */
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7 * 8, /* %r15 */
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16 * 8, /* %rip */
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17 * 8, /* %eflags */
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-1, /* %ds */
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-1, /* %es */
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/* FIXME: kettenis/2002030531: The registers %fs and %gs are
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available in `struct sigcontext'. However, they only occupy two
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bytes instead of four, which makes using them here rather
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difficult. Leave them out for now. */
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-1, /* %fs */
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-1 /* %gs */
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};
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static void
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x86_64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
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{
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struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
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x86_64_init_abi (info, gdbarch);
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set_gdbarch_pc_in_sigtramp (gdbarch, x86_64_linux_pc_in_sigtramp);
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tdep->sigcontext_addr = x86_64_linux_sigcontext_addr;
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tdep->sc_reg_offset = x86_64_linux_sc_reg_offset;
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tdep->sc_num_regs = X86_64_NUM_GREGS;
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}
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/* Provide a prototype to silence -Wmissing-prototypes. */
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extern void _initialize_x86_64_linux_tdep (void);
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void
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_initialize_x86_64_linux_tdep (void)
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{
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add_core_fns (&x86_64_core_fns);
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gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64, GDB_OSABI_LINUX,
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x86_64_linux_init_abi);
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}
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