[deliverable/binutils-gdb.git] / gdb / x86-64-linux-tdep.c

/* Target-dependent code for GNU/Linux running on x86-64, for GDB.

   Copyright 2001, 2003 Free Software Foundation, Inc.

   Contributed by Jiri Smid, SuSE Labs.

   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 2 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, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include "defs.h"
#include "inferior.h"
#include "gdbcore.h"
#include "regcache.h"
#include "osabi.h"

#include "gdb_string.h"

#include "x86-64-tdep.h"
#include "x86-64-linux-tdep.h"

/* Register indexes to 'struct user' come from <sys/reg.h>.  */

#define USER_R15    0
#define USER_R14    1
#define USER_R13    2
#define USER_R12    3
#define USER_RBP    4
#define USER_RBX    5
#define USER_R11    6
#define USER_R10    7
#define USER_R9     8
#define USER_R8     9
#define USER_RAX    10
#define USER_RCX    11
#define USER_RDX    12
#define USER_RSI    13
#define USER_RDI    14
#define USER_RIP    16
#define USER_CS     17
#define USER_EFLAGS 18
#define USER_RSP    19
#define USER_SS     20
#define USER_DS     23
#define USER_ES     24
#define USER_FS     25
#define USER_GS     26

/* Mapping between the general-purpose registers in `struct user'
   format and GDB's register array layout.  */

static int user_to_gdb_regmap[] =
{
  USER_RAX, USER_RBX, USER_RCX, USER_RDX,
  USER_RSI, USER_RDI, USER_RBP, USER_RSP,
  USER_R8, USER_R9, USER_R10, USER_R11,
  USER_R12, USER_R13, USER_R14, USER_R15,
  USER_RIP, USER_EFLAGS,
  USER_DS, USER_ES, USER_FS, USER_GS
};

/* Fill GDB's register array with the general-purpose register values
   in *GREGSETP.  */

void
x86_64_linux_supply_gregset (char *regp)
{
  int i;

  for (i = 0; i < X86_64_NUM_GREGS; i++)
    supply_register (i, regp + (user_to_gdb_regmap[i] * 8));
}

/* Fill register REGNO (if it is a general-purpose register) in
   *GREGSETPS with the value in GDB's register array.  If REGNO is -1,
   do this for all registers.  */

void
x86_64_linux_fill_gregset (char *regp, int regno)
{
  int i;

  for (i = 0; i < X86_64_NUM_GREGS; i++)
    if (regno == -1 || regno == i)
      regcache_collect (i, regp + (user_to_gdb_regmap[i] * 8));
}

/* The register sets used in GNU/Linux ELF core-dumps are identical to
   the register sets used by `ptrace'.  The corresponding types are
   `elf_gregset_t' for the general-purpose registers (with
   `elf_greg_t' the type of a single GP register) and `elf_fpregset_t'
   for the floating-point registers.  */

static void
fetch_core_registers (char *core_reg_sect, unsigned core_reg_size,
			 int which, CORE_ADDR ignore)
{
  switch (which)
    {
    case 0:  /* Integer registers.  */
      if (core_reg_size != 216)
	warning ("Wrong size register set in core file.");
      else
	x86_64_linux_supply_gregset (core_reg_sect);
      break;

    case 2:  /* Floating point registers.  */
    case 3:  /* "Extended" floating point registers.  This is gdb-speak
		for SSE/SSE2. */
      if (core_reg_size != 512)
	warning ("Wrong size XMM register set in core file.");
      else
	x86_64_supply_fxsave (current_regcache, -1, core_reg_sect);
      break;

    default:
      /* Don't know what kind of register request this is; just ignore it.  */
      break;
    }
}

static struct core_fns x86_64_core_fns = 
{
  bfd_target_elf_flavour,		/* core_flavour */
  default_check_format,			/* check_format */
  default_core_sniffer,			/* core_sniffer */
  fetch_core_registers,			/* core_read_registers */
  NULL					/* next */
};

#define LINUX_SIGTRAMP_INSN0	0x48	/* mov $NNNNNNNN, %rax */
#define LINUX_SIGTRAMP_OFFSET0	0
#define LINUX_SIGTRAMP_INSN1	0x0f	/* syscall */
#define LINUX_SIGTRAMP_OFFSET1	7

static const unsigned char linux_sigtramp_code[] =
{
  /* mov $__NR_rt_sigreturn, %rax */
  LINUX_SIGTRAMP_INSN0, 0xc7, 0xc0, 0x0f, 0x00, 0x00, 0x00,
  /* syscall */
  LINUX_SIGTRAMP_INSN1, 0x05
};

#define LINUX_SIGTRAMP_LEN (sizeof linux_sigtramp_code)

/* If PC is in a sigtramp routine, return the address of the start of
   the routine.  Otherwise, return 0.  */

static CORE_ADDR
x86_64_linux_sigtramp_start (CORE_ADDR pc)
{
  unsigned char buf[LINUX_SIGTRAMP_LEN];

  /* We only recognize a signal trampoline if PC is at the start of
     one of the two instructions.  We optimize for finding the PC at
     the start, as will be the case when the trampoline is not the
     first frame on the stack.  We assume that in the case where the
     PC is not at the start of the instruction sequence, there will be
     a few trailing readable bytes on the stack.  */

  if (read_memory_nobpt (pc, (char *) buf, LINUX_SIGTRAMP_LEN) != 0)
    return 0;

  if (buf[0] != LINUX_SIGTRAMP_INSN0)
    {
      if (buf[0] != LINUX_SIGTRAMP_INSN1)
	return 0;

      pc -= LINUX_SIGTRAMP_OFFSET1;

      if (read_memory_nobpt (pc, (char *) buf, LINUX_SIGTRAMP_LEN) != 0)
	return 0;
    }

  if (memcmp (buf, linux_sigtramp_code, LINUX_SIGTRAMP_LEN) != 0)
    return 0;

  return pc;
}

/* Return whether PC is in a GNU/Linux sigtramp routine.  */

static int
x86_64_linux_pc_in_sigtramp (CORE_ADDR pc, char *name)
{
  /* If we have NAME, we can optimize the search.  The trampoline is
     named __restore_rt.  However, it isn't dynamically exported from
     the shared C library, so the trampoline may appear to be part of
     the preceding function.  This should always be sigaction,
     __sigaction, or __libc_sigaction (all aliases to the same
     function).  */
  if (name == NULL || strstr (name, "sigaction") != NULL)
    return (x86_64_linux_sigtramp_start (pc) != 0);

  return (strcmp ("__restore_rt", name) == 0);
}

/* Offset to struct sigcontext in ucontext, from <asm/ucontext.h>.  */
#define X86_64_LINUX_UCONTEXT_SIGCONTEXT_OFFSET 40

/* Assuming NEXT_FRAME is a frame following a GNU/Linux sigtramp
   routine, return the address of the associated sigcontext structure.  */

static CORE_ADDR
x86_64_linux_sigcontext_addr (struct frame_info *next_frame)
{
  CORE_ADDR sp;
  char buf[8];

  frame_unwind_register (next_frame, SP_REGNUM, buf);
  sp = extract_unsigned_integer (buf, 8);

  /* The sigcontext structure is part of the user context.  A pointer
     to the user context is passed as the third argument to the signal
     handler, i.e. in %rdx.  Unfortunately %rdx isn't preserved across
     function calls so we can't use it.  Fortunately the user context
     is part of the signal frame and the unwound %rsp directly points
     at it.  */
  return sp + X86_64_LINUX_UCONTEXT_SIGCONTEXT_OFFSET;
}
\f

/* From <asm/sigcontext.h>.  */
static int x86_64_linux_sc_reg_offset[X86_64_NUM_GREGS] =
{
  13 * 8,			/* %rax */
  11 * 8,			/* %rbx */
  14 * 8,			/* %rcx */
  12 * 8,			/* %rdx */
  9 * 8,			/* %rsi */
  8 * 8,			/* %rdi */
  10 * 8,			/* %rbp */
  15 * 8,			/* %rsp */
  0 * 8,			/* %r8 */
  1 * 8,			/* %r9 */
  2 * 8,			/* %r10 */
  3 * 8,			/* %r11 */
  4 * 8,			/* %r12 */
  5 * 8,			/* %r13 */
  6 * 8,			/* %r14 */
  7 * 8,			/* %r15 */
  16 * 8,			/* %rip */
  17 * 8,			/* %eflags */
  -1,				/* %ds */
  -1,				/* %es */

  /* FIXME: kettenis/2002030531: The registers %fs and %gs are
     available in `struct sigcontext'.  However, they only occupy two
     bytes instead of four, which makes using them here rather
     difficult.  Leave them out for now.  */
  -1,				/* %fs */
  -1				/* %gs */
};

static void
x86_64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
  x86_64_init_abi (info, gdbarch);

  set_gdbarch_pc_in_sigtramp (gdbarch, x86_64_linux_pc_in_sigtramp);

  tdep->sigcontext_addr = x86_64_linux_sigcontext_addr;
  tdep->sc_reg_offset = x86_64_linux_sc_reg_offset;
  tdep->sc_num_regs = X86_64_NUM_GREGS;
}
\f

/* Provide a prototype to silence -Wmissing-prototypes.  */
extern void _initialize_x86_64_linux_tdep (void);

void
_initialize_x86_64_linux_tdep (void)
{
  add_core_fns (&x86_64_core_fns);

  gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64, GDB_OSABI_LINUX,
			  x86_64_linux_init_abi);
}
Commit	Line	Data
a4b6fc86 AC	1	/* Target-dependent code for GNU/Linux running on x86-64, for GDB.
a4b6fc86 AC	2
1bac305b	3	Copyright 2001, 2003 Free Software Foundation, Inc.
a4b6fc86	4
53e95fcf JS	5	Contributed by Jiri Smid, SuSE Labs.
	6
	7	This file is part of GDB.
	8
	9	This program is free software; you can redistribute it and/or modify
	10	it under the terms of the GNU General Public License as published by
	11	the Free Software Foundation; either version 2 of the License, or
	12	(at your option) any later version.
	13
	14	This program is distributed in the hope that it will be useful,
	15	but WITHOUT ANY WARRANTY; without even the implied warranty of
	16	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	17	GNU General Public License for more details.
	18
	19	You should have received a copy of the GNU General Public License
	20	along with this program; if not, write to the Free Software
	21	Foundation, Inc., 59 Temple Place - Suite 330,
	22	Boston, MA 02111-1307, USA. */
	23
	24	#include "defs.h"
	25	#include "inferior.h"
	26	#include "gdbcore.h"
	27	#include "regcache.h"
84dc46cb	28	#include "osabi.h"
53e95fcf	29
c4f35dd8	30	#include "gdb_string.h"
53e95fcf	31
c4f35dd8	32	#include "x86-64-tdep.h"
eba29c8c ML	33	#include "x86-64-linux-tdep.h"
	34
	35	/* Register indexes to 'struct user' come from <sys/reg.h>. */
	36
	37	#define USER_R15 0
	38	#define USER_R14 1
	39	#define USER_R13 2
	40	#define USER_R12 3
	41	#define USER_RBP 4
	42	#define USER_RBX 5
	43	#define USER_R11 6
	44	#define USER_R10 7
	45	#define USER_R9 8
	46	#define USER_R8 9
	47	#define USER_RAX 10
	48	#define USER_RCX 11
	49	#define USER_RDX 12
	50	#define USER_RSI 13
	51	#define USER_RDI 14
	52	#define USER_RIP 16
	53	#define USER_CS 17
	54	#define USER_EFLAGS 18
	55	#define USER_RSP 19
	56	#define USER_SS 20
	57	#define USER_DS 23
	58	#define USER_ES 24
	59	#define USER_FS 25
	60	#define USER_GS 26
	61
	62	/* Mapping between the general-purpose registers in `struct user'
	63	format and GDB's register array layout. */
	64
	65	static int user_to_gdb_regmap[] =
	66	{
	67	USER_RAX, USER_RBX, USER_RCX, USER_RDX,
	68	USER_RSI, USER_RDI, USER_RBP, USER_RSP,
	69	USER_R8, USER_R9, USER_R10, USER_R11,
	70	USER_R12, USER_R13, USER_R14, USER_R15,
b0f5c6f2	71	USER_RIP, USER_EFLAGS,
eba29c8c ML	72	USER_DS, USER_ES, USER_FS, USER_GS
	73	};
	74
	75	/* Fill GDB's register array with the general-purpose register values
	76	in GREGSETP. /
	77
	78	void
	79	x86_64_linux_supply_gregset (char *regp)
	80	{
	81	int i;
	82
	83	for (i = 0; i < X86_64_NUM_GREGS; i++)
	84	supply_register (i, regp + (user_to_gdb_regmap[i] * 8));
	85	}
	86
	87	/* Fill register REGNO (if it is a general-purpose register) in
	88	*GREGSETPS with the value in GDB's register array. If REGNO is -1,
	89	do this for all registers. */
	90
	91	void
	92	x86_64_linux_fill_gregset (char *regp, int regno)
	93	{
	94	int i;
	95
	96	for (i = 0; i < X86_64_NUM_GREGS; i++)
	97	if (regno == -1 \|\| regno == i)
	98	regcache_collect (i, regp + (user_to_gdb_regmap[i] * 8));
	99	}
	100
	101	/* The register sets used in GNU/Linux ELF core-dumps are identical to
	102	the register sets used by `ptrace'. The corresponding types are
	103	`elf_gregset_t' for the general-purpose registers (with
	104	`elf_greg_t' the type of a single GP register) and `elf_fpregset_t'
	105	for the floating-point registers. */
	106
	107	static void
	108	fetch_core_registers (char *core_reg_sect, unsigned core_reg_size,
	109	int which, CORE_ADDR ignore)
	110	{
	111	switch (which)
	112	{
	113	case 0: /* Integer registers. */
	114	if (core_reg_size != 216)
	115	warning ("Wrong size register set in core file.");
	116	else
	117	x86_64_linux_supply_gregset (core_reg_sect);
	118	break;
	119
	120	case 2: /* Floating point registers. */
	121	case 3: /* "Extended" floating point registers. This is gdb-speak
	122	for SSE/SSE2. */
	123	if (core_reg_size != 512)
	124	warning ("Wrong size XMM register set in core file.");
	125	else
41d041d6	126	x86_64_supply_fxsave (current_regcache, -1, core_reg_sect);
eba29c8c ML	127	break;
	128
	129	default:
	130	/* Don't know what kind of register request this is; just ignore it. */
	131	break;
	132	}
	133	}
	134
	135	static struct core_fns x86_64_core_fns =
	136	{
	137	bfd_target_elf_flavour, /* core_flavour */
	138	default_check_format, /* check_format */
	139	default_core_sniffer, /* core_sniffer */
	140	fetch_core_registers, /* core_read_registers */
	141	NULL /* next */
	142	};
c4f35dd8 MK	143
	144	#define LINUX_SIGTRAMP_INSN0 0x48 /* mov $NNNNNNNN, %rax */
	145	#define LINUX_SIGTRAMP_OFFSET0 0
	146	#define LINUX_SIGTRAMP_INSN1 0x0f /* syscall */
	147	#define LINUX_SIGTRAMP_OFFSET1 7
	148
	149	static const unsigned char linux_sigtramp_code[] =
	150	{
	151	/* mov $__NR_rt_sigreturn, %rax */
baed091b ML	152	LINUX_SIGTRAMP_INSN0, 0xc7, 0xc0, 0x0f, 0x00, 0x00, 0x00,
	153	/* syscall */
	154	LINUX_SIGTRAMP_INSN1, 0x05
53e95fcf JS	155	};
	156
	157	#define LINUX_SIGTRAMP_LEN (sizeof linux_sigtramp_code)
	158
	159	/* If PC is in a sigtramp routine, return the address of the start of
	160	the routine. Otherwise, return 0. */
	161
	162	static CORE_ADDR
	163	x86_64_linux_sigtramp_start (CORE_ADDR pc)
	164	{
	165	unsigned char buf[LINUX_SIGTRAMP_LEN];
c4f35dd8 MK	166
	167	/* We only recognize a signal trampoline if PC is at the start of
	168	one of the two instructions. We optimize for finding the PC at
	169	the start, as will be the case when the trampoline is not the
	170	first frame on the stack. We assume that in the case where the
	171	PC is not at the start of the instruction sequence, there will be
	172	a few trailing readable bytes on the stack. */
	173
53e95fcf JS	174	if (read_memory_nobpt (pc, (char *) buf, LINUX_SIGTRAMP_LEN) != 0)
	175	return 0;
	176
	177	if (buf[0] != LINUX_SIGTRAMP_INSN0)
	178	{
	179	if (buf[0] != LINUX_SIGTRAMP_INSN1)
	180	return 0;
	181
	182	pc -= LINUX_SIGTRAMP_OFFSET1;
	183
	184	if (read_memory_nobpt (pc, (char *) buf, LINUX_SIGTRAMP_LEN) != 0)
	185	return 0;
	186	}
	187
	188	if (memcmp (buf, linux_sigtramp_code, LINUX_SIGTRAMP_LEN) != 0)
	189	return 0;
	190
	191	return pc;
	192	}
	193
baed091b ML	194	/* Return whether PC is in a GNU/Linux sigtramp routine. */
baed091b ML	195
c4f35dd8 MK	196	static int
c4f35dd8 MK	197	x86_64_linux_pc_in_sigtramp (CORE_ADDR pc, char *name)
baed091b	198	{
c4f35dd8 MK	199	/* If we have NAME, we can optimize the search. The trampoline is
	200	named __restore_rt. However, it isn't dynamically exported from
	201	the shared C library, so the trampoline may appear to be part of
	202	the preceding function. This should always be sigaction,
	203	__sigaction, or __libc_sigaction (all aliases to the same
	204	function). */
	205	if (name == NULL \|\| strstr (name, "sigaction") != NULL)
	206	return (x86_64_linux_sigtramp_start (pc) != 0);
	207
	208	return (strcmp ("__restore_rt", name) == 0);
baed091b ML	209	}
baed091b ML	210
c4f35dd8 MK	211	/* Offset to struct sigcontext in ucontext, from <asm/ucontext.h>. */
c4f35dd8 MK	212	#define X86_64_LINUX_UCONTEXT_SIGCONTEXT_OFFSET 40
b64bbf8c	213
c4f35dd8 MK	214	/* Assuming NEXT_FRAME is a frame following a GNU/Linux sigtramp
c4f35dd8 MK	215	routine, return the address of the associated sigcontext structure. */
baed091b	216
c4f35dd8 MK	217	static CORE_ADDR
c4f35dd8 MK	218	x86_64_linux_sigcontext_addr (struct frame_info *next_frame)
baed091b	219	{
c4f35dd8 MK	220	CORE_ADDR sp;
	221	char buf[8];
	222
	223	frame_unwind_register (next_frame, SP_REGNUM, buf);
	224	sp = extract_unsigned_integer (buf, 8);
	225
	226	/* The sigcontext structure is part of the user context. A pointer
	227	to the user context is passed as the third argument to the signal
	228	handler, i.e. in %rdx. Unfortunately %rdx isn't preserved across
	229	function calls so we can't use it. Fortunately the user context
	230	is part of the signal frame and the unwound %rsp directly points
	231	at it. */
	232	return sp + X86_64_LINUX_UCONTEXT_SIGCONTEXT_OFFSET;
baed091b	233	}
2213a65d MK	234	\f
2213a65d MK	235
2b5e0749 MK	236	/* From <asm/sigcontext.h>. */
	237	static int x86_64_linux_sc_reg_offset[X86_64_NUM_GREGS] =
	238	{
	239	13 * 8, /* %rax */
	240	11 * 8, /* %rbx */
	241	14 * 8, /* %rcx */
	242	12 * 8, /* %rdx */
	243	9 * 8, /* %rsi */
	244	8 * 8, /* %rdi */
	245	10 * 8, /* %rbp */
	246	15 * 8, /* %rsp */
	247	0 * 8, /* %r8 */
	248	1 * 8, /* %r9 */
	249	2 * 8, /* %r10 */
	250	3 * 8, /* %r11 */
	251	4 * 8, /* %r12 */
	252	5 * 8, /* %r13 */
	253	6 * 8, /* %r14 */
	254	7 * 8, /* %r15 */
	255	16 * 8, /* %rip */
	256	17 * 8, /* %eflags */
	257	-1, /* %ds */
	258	-1, /* %es */
	259
	260	/* FIXME: kettenis/2002030531: The registers %fs and %gs are
	261	available in `struct sigcontext'. However, they only occupy two
	262	bytes instead of four, which makes using them here rather
	263	difficult. Leave them out for now. */
	264	-1, /* %fs */
	265	-1 /* %gs */
	266	};
	267
2213a65d MK	268	static void
	269	x86_64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
	270	{
c4f35dd8	271	struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
2213a65d	272	x86_64_init_abi (info, gdbarch);
c4f35dd8 MK	273
	274	set_gdbarch_pc_in_sigtramp (gdbarch, x86_64_linux_pc_in_sigtramp);
	275
	276	tdep->sigcontext_addr = x86_64_linux_sigcontext_addr;
2b5e0749 MK	277	tdep->sc_reg_offset = x86_64_linux_sc_reg_offset;
2b5e0749 MK	278	tdep->sc_num_regs = X86_64_NUM_GREGS;
2213a65d	279	}
c4f35dd8	280	\f
2213a65d MK	281
	282	/* Provide a prototype to silence -Wmissing-prototypes. */
	283	extern void _initialize_x86_64_linux_tdep (void);
	284
	285	void
	286	_initialize_x86_64_linux_tdep (void)
	287	{
eba29c8c ML	288	add_core_fns (&x86_64_core_fns);
eba29c8c ML	289
2213a65d MK	290	gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64, GDB_OSABI_LINUX,
	291	x86_64_linux_init_abi);
	292	}