[deliverable/binutils-gdb.git] / gdb / amd64obsd-tdep.c

/* Target-dependent code for OpenBSD/amd64.

   Copyright 2003, 2004, 2005 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 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 "frame.h"
#include "gdbcore.h"
#include "symtab.h"
#include "objfiles.h"
#include "osabi.h"
#include "regcache.h"
#include "regset.h"
#include "target.h"

#include "gdb_assert.h"
#include "gdb_string.h"

#include "amd64-tdep.h"
#include "i387-tdep.h"
#include "solib-svr4.h"
#include "bsd-uthread.h"

/* Support for core dumps.  */

static void
amd64obsd_supply_regset (const struct regset *regset,
			 struct regcache *regcache, int regnum,
			 const void *regs, size_t len)
{
  const struct gdbarch_tdep *tdep = gdbarch_tdep (regset->arch);

  gdb_assert (len >= tdep->sizeof_gregset + I387_SIZEOF_FXSAVE);

  i386_supply_gregset (regset, regcache, regnum, regs, tdep->sizeof_gregset);
  amd64_supply_fxsave (regcache, regnum,
		       ((const gdb_byte *)regs) + tdep->sizeof_gregset);
}

static const struct regset *
amd64obsd_regset_from_core_section (struct gdbarch *gdbarch,
				    const char *sect_name, size_t sect_size)
{
  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

  /* OpenBSD core dumps don't use seperate register sets for the
     general-purpose and floating-point registers.  */

  if (strcmp (sect_name, ".reg") == 0
      && sect_size >= tdep->sizeof_gregset + I387_SIZEOF_FXSAVE)
    {
      if (tdep->gregset == NULL)
        tdep->gregset = regset_alloc (gdbarch, amd64obsd_supply_regset, NULL);
      return tdep->gregset;
    }

  return NULL;
}
\f

/* Support for signal handlers.  */

/* Default page size.  */
static const int amd64obsd_page_size = 4096;

/* Return whether the frame preceding NEXT_FRAME corresponds to an
   OpenBSD sigtramp routine.  */

static int
amd64obsd_sigtramp_p (struct frame_info *next_frame)
{
  CORE_ADDR pc = frame_pc_unwind (next_frame);
  CORE_ADDR start_pc = (pc & ~(amd64obsd_page_size - 1));
  const gdb_byte sigreturn[] =
  {
    0x48, 0xc7, 0xc0,
    0x67, 0x00, 0x00, 0x00,	/* movq $SYS_sigreturn, %rax */
    0xcd, 0x80			/* int $0x80 */
  };
  size_t buflen = (sizeof sigreturn) + 1;
  gdb_byte *buf;
  char *name;

  /* If the function has a valid symbol name, it isn't a
     trampoline.  */
  find_pc_partial_function (pc, &name, NULL, NULL);
  if (name != NULL)
    return 0;

  /* If the function lives in a valid section (even without a starting
     point) it isn't a trampoline.  */
  if (find_pc_section (pc) != NULL)
    return 0;

  /* If we can't read the instructions at START_PC, return zero.  */
  buf = alloca ((sizeof sigreturn) + 1);
  if (!safe_frame_unwind_memory (next_frame, start_pc + 6, buf, buflen))
    return 0;

  /* Check for sigreturn(2).  Depending on how the assembler encoded
     the `movq %rsp, %rdi' instruction, the code starts at offset 6 or
     7.  */
  if (memcmp (buf, sigreturn, sizeof sigreturn)
      && memcpy (buf + 1, sigreturn, sizeof sigreturn))
    return 0;

  return 1;
}

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

static CORE_ADDR
amd64obsd_sigcontext_addr (struct frame_info *next_frame)
{
  CORE_ADDR pc = frame_pc_unwind (next_frame);
  ULONGEST offset = (pc & (amd64obsd_page_size - 1));

  /* The %rsp register points at `struct sigcontext' upon entry of a
     signal trampoline.  The relevant part of the trampoline is

        call    *%rax
        movq    %rsp, %rdi
        pushq   %rdi
        movq    $SYS_sigreturn,%rax
        int     $0x80

     (see /usr/src/sys/arch/amd64/amd64/locore.S).  The `pushq'
     instruction clobbers %rsp, but its value is saved in `%rdi'.  */

  if (offset > 5)
    return frame_unwind_register_unsigned (next_frame, AMD64_RDI_REGNUM);
  else
    return frame_unwind_register_unsigned (next_frame, AMD64_RSP_REGNUM);
}
\f
/* OpenBSD 3.5 or later.  */

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

/* From <machine/reg.h>.  */
int amd64obsd_r_reg_offset[] =
{
  14 * 8,			/* %rax */
  13 * 8,			/* %rbx */
  3 * 8,			/* %rcx */
  2 * 8,			/* %rdx */
  1 * 8,			/* %rsi */
  0 * 8,			/* %rdi */
  12 * 8,			/* %rbp */
  15 * 8,			/* %rsp */
  4 * 8,			/* %r8 .. */
  5 * 8,
  6 * 8,
  7 * 8,
  8 * 8,
  9 * 8,
  10 * 8,
  11 * 8,			/* ... %r15 */
  16 * 8,			/* %rip */
  17 * 8,			/* %eflags */
  18 * 8,			/* %cs */
  19 * 8,			/* %ss */
  20 * 8,			/* %ds */
  21 * 8,			/* %es */
  22 * 8,			/* %fs */
  23 * 8			/* %gs */
};

/* From <machine/signal.h>.  */
static int amd64obsd_sc_reg_offset[] =
{
  14 * 8,			/* %rax */
  13 * 8,			/* %rbx */
  3 * 8,			/* %rcx */
  2 * 8,			/* %rdx */
  1 * 8,			/* %rsi */
  0 * 8,			/* %rdi */
  12 * 8,			/* %rbp */
  24 * 8,			/* %rsp */
  4 * 8,			/* %r8 ... */
  5 * 8,
  6 * 8,
  7 * 8,
  8 * 8,
  9 * 8,
  10 * 8,
  11 * 8,			/* ... %r15 */
  21 * 8,			/* %rip */
  23 * 8,			/* %eflags */
  22 * 8,			/* %cs */
  25 * 8,			/* %ss */
  18 * 8,			/* %ds */
  17 * 8,			/* %es */
  16 * 8,			/* %fs */
  15 * 8			/* %gs */
};

/* From /usr/src/lib/libpthread/arch/amd64/uthread_machdep.c.  */
static int amd64obsd_uthread_reg_offset[] =
{
  19 * 8,			/* %rax */
  16 * 8,			/* %rbx */
  18 * 8,			/* %rcx */
  17 * 8,			/* %rdx */
  14 * 8,			/* %rsi */
  13 * 8,			/* %rdi */
  15 * 8,			/* %rbp */
  -1,				/* %rsp */
  12 * 8,			/* %r8 ... */
  11 * 8,
  10 * 8,
  9 * 8,
  8 * 8,
  7 * 8,
  6 * 8,
  5 * 8,			/* ... %r15 */
  20 * 8,			/* %rip */
  4 * 8,			/* %eflags */
  21 * 8,			/* %cs */
  -1,				/* %ss */
  3 * 8,			/* %ds */
  2 * 8,			/* %es */
  1 * 8,			/* %fs */
  0 * 8				/* %gs */
};

/* Offset within the thread structure where we can find the saved
   stack pointer (%esp).  */
#define AMD64OBSD_UTHREAD_RSP_OFFSET	400

static void
amd64obsd_supply_uthread (struct regcache *regcache,
			  int regnum, CORE_ADDR addr)
{
  CORE_ADDR sp_addr = addr + AMD64OBSD_UTHREAD_RSP_OFFSET;
  CORE_ADDR sp = 0;
  gdb_byte buf[8];
  int i;

  gdb_assert (regnum >= -1);

  if (regnum == -1 || regnum == AMD64_RSP_REGNUM)
    {
      int offset;

      /* Fetch stack pointer from thread structure.  */
      sp = read_memory_unsigned_integer (sp_addr, 8);

      /* Adjust the stack pointer such that it looks as if we just
         returned from _thread_machdep_switch.  */
      offset = amd64obsd_uthread_reg_offset[AMD64_RIP_REGNUM] + 8;
      store_unsigned_integer (buf, 8, sp + offset);
      regcache_raw_supply (regcache, AMD64_RSP_REGNUM, buf);
    }

  for (i = 0; i < ARRAY_SIZE (amd64obsd_uthread_reg_offset); i++)
    {
      if (amd64obsd_uthread_reg_offset[i] != -1
	  && (regnum == -1 || regnum == i))
	{
	  /* Fetch stack pointer from thread structure (if we didn't
             do so already).  */
	  if (sp == 0)
	    sp = read_memory_unsigned_integer (sp_addr, 8);

	  /* Read the saved register from the stack frame.  */
	  read_memory (sp + amd64obsd_uthread_reg_offset[i], buf, 8);
	  regcache_raw_supply (regcache, i, buf);
	}
    }
}

static void
amd64obsd_collect_uthread (const struct regcache *regcache,
			   int regnum, CORE_ADDR addr)
{
  CORE_ADDR sp_addr = addr + AMD64OBSD_UTHREAD_RSP_OFFSET;
  CORE_ADDR sp = 0;
  gdb_byte buf[8];
  int i;

  gdb_assert (regnum >= -1);

  if (regnum == -1 || regnum == AMD64_RSP_REGNUM)
    {
      int offset;

      /* Calculate the stack pointer (frame pointer) that will be
         stored into the thread structure.  */
      offset = amd64obsd_uthread_reg_offset[AMD64_RIP_REGNUM] + 8;
      regcache_raw_collect (regcache, AMD64_RSP_REGNUM, buf);
      sp = extract_unsigned_integer (buf, 8) - offset;

      /* Store the stack pointer.  */
      write_memory_unsigned_integer (sp_addr, 8, sp);

      /* The stack pointer was (potentially) modified.  Make sure we
         build a proper stack frame.  */
      regnum = -1;
    }

  for (i = 0; i < ARRAY_SIZE (amd64obsd_uthread_reg_offset); i++)
    {
      if (amd64obsd_uthread_reg_offset[i] != -1
	  && (regnum == -1 || regnum == i))
	{
	  /* Fetch stack pointer from thread structure (if we didn't
             calculate it already).  */
	  if (sp == 0)
	    sp = read_memory_unsigned_integer (sp_addr, 8);

	  /* Write the register into the stack frame.  */
	  regcache_raw_collect (regcache, i, buf);
	  write_memory (sp + amd64obsd_uthread_reg_offset[i], buf, 8);
	}
    }
}

static void
amd64obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

  amd64_init_abi (info, gdbarch);

  /* Initialize general-purpose register set details.  */
  tdep->gregset_reg_offset = amd64obsd_r_reg_offset;
  tdep->gregset_num_regs = ARRAY_SIZE (amd64obsd_r_reg_offset);
  tdep->sizeof_gregset = 24 * 8;

  set_gdbarch_regset_from_core_section (gdbarch,
					amd64obsd_regset_from_core_section);

  tdep->jb_pc_offset = 7 * 8;

  tdep->sigtramp_p = amd64obsd_sigtramp_p;
  tdep->sigcontext_addr = amd64obsd_sigcontext_addr;
  tdep->sc_reg_offset = amd64obsd_sc_reg_offset;
  tdep->sc_num_regs = ARRAY_SIZE (amd64obsd_sc_reg_offset);

  /* OpenBSD provides a user-level threads implementation.  */
  bsd_uthread_set_supply_uthread (gdbarch, amd64obsd_supply_uthread);
  bsd_uthread_set_collect_uthread (gdbarch, amd64obsd_collect_uthread);

  /* OpenBSD uses SVR4-style shared libraries.  */
  set_solib_svr4_fetch_link_map_offsets
    (gdbarch, svr4_lp64_fetch_link_map_offsets);
}
\f

/* Provide a prototype to silence -Wmissing-prototypes.  */
void _initialize_amd64obsd_tdep (void);

void
_initialize_amd64obsd_tdep (void)
{
  /* The OpenBSD/amd64 native dependent code makes this assumption.  */
  gdb_assert (ARRAY_SIZE (amd64obsd_r_reg_offset) == AMD64_NUM_GREGS);

  gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64,
			  GDB_OSABI_OPENBSD_ELF, amd64obsd_init_abi);

  /* OpenBSD uses traditional (a.out) NetBSD-style core dumps.  */
  gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64,
			  GDB_OSABI_NETBSD_AOUT, amd64obsd_init_abi);
}
Commit	Line	Data
e2879ccb MK	1	/* Target-dependent code for OpenBSD/amd64.
e2879ccb MK	2
d8de1ef7	3	Copyright 2003, 2004, 2005 Free Software Foundation, Inc.
e2879ccb MK	4
	5	This file is part of GDB.
	6
	7	This program is free software; you can redistribute it and/or modify
	8	it under the terms of the GNU General Public License as published by
	9	the Free Software Foundation; either version 2 of the License, or
	10	(at your option) any later version.
	11
	12	This program is distributed in the hope that it will be useful,
	13	but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	GNU General Public License for more details.
	16
	17	You should have received a copy of the GNU General Public License
	18	along with this program; if not, write to the Free Software
	19	Foundation, Inc., 59 Temple Place - Suite 330,
	20	Boston, MA 02111-1307, USA. */
	21
	22	#include "defs.h"
	23	#include "frame.h"
	24	#include "gdbcore.h"
911bc6ee MK	25	#include "symtab.h"
911bc6ee MK	26	#include "objfiles.h"
e2879ccb	27	#include "osabi.h"
d78749b4	28	#include "regcache.h"
30b344b1	29	#include "regset.h"
e2879ccb MK	30	#include "target.h"
	31
	32	#include "gdb_assert.h"
	33	#include "gdb_string.h"
	34
85be1ca6	35	#include "amd64-tdep.h"
30b344b1	36	#include "i387-tdep.h"
7e654c37	37	#include "solib-svr4.h"
d78749b4	38	#include "bsd-uthread.h"
30b344b1 MK	39
	40	/* Support for core dumps. */
	41
	42	static void
	43	amd64obsd_supply_regset (const struct regset *regset,
	44	struct regcache *regcache, int regnum,
	45	const void *regs, size_t len)
	46	{
9ea75c57	47	const struct gdbarch_tdep *tdep = gdbarch_tdep (regset->arch);
30b344b1 MK	48
	49	gdb_assert (len >= tdep->sizeof_gregset + I387_SIZEOF_FXSAVE);
	50
	51	i386_supply_gregset (regset, regcache, regnum, regs, tdep->sizeof_gregset);
d8de1ef7 MK	52	amd64_supply_fxsave (regcache, regnum,
d8de1ef7 MK	53	((const gdb_byte *)regs) + tdep->sizeof_gregset);
30b344b1 MK	54	}
	55
	56	static const struct regset *
	57	amd64obsd_regset_from_core_section (struct gdbarch *gdbarch,
	58	const char *sect_name, size_t sect_size)
	59	{
	60	struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
	61
	62	/* OpenBSD core dumps don't use seperate register sets for the
	63	general-purpose and floating-point registers. */
	64
	65	if (strcmp (sect_name, ".reg") == 0
	66	&& sect_size >= tdep->sizeof_gregset + I387_SIZEOF_FXSAVE)
	67	{
	68	if (tdep->gregset == NULL)
9ea75c57	69	tdep->gregset = regset_alloc (gdbarch, amd64obsd_supply_regset, NULL);
30b344b1 MK	70	return tdep->gregset;
	71	}
	72
	73	return NULL;
	74	}
	75	\f
e2879ccb MK	76
	77	/* Support for signal handlers. */
	78
911bc6ee	79	/* Default page size. */
e2879ccb MK	80	static const int amd64obsd_page_size = 4096;
e2879ccb MK	81
377d9ebd	82	/* Return whether the frame preceding NEXT_FRAME corresponds to an
911bc6ee MK	83	OpenBSD sigtramp routine. */
911bc6ee MK	84
e2879ccb	85	static int
911bc6ee	86	amd64obsd_sigtramp_p (struct frame_info *next_frame)
e2879ccb	87	{
911bc6ee	88	CORE_ADDR pc = frame_pc_unwind (next_frame);
e2879ccb	89	CORE_ADDR start_pc = (pc & ~(amd64obsd_page_size - 1));
d8de1ef7	90	const gdb_byte sigreturn[] =
e2879ccb MK	91	{
	92	0x48, 0xc7, 0xc0,
	93	0x67, 0x00, 0x00, 0x00, /* movq $SYS_sigreturn, %rax */
84d04465	94	0xcd, 0x80 /* int $0x80 */
e2879ccb	95	};
1c5bf419	96	size_t buflen = (sizeof sigreturn) + 1;
d8de1ef7 MK	97	gdb_byte *buf;
d8de1ef7 MK	98	char *name;
911bc6ee MK	99
	100	/* If the function has a valid symbol name, it isn't a
	101	trampoline. */
	102	find_pc_partial_function (pc, &name, NULL, NULL);
	103	if (name != NULL)
	104	return 0;
e2879ccb	105
911bc6ee MK	106	/* If the function lives in a valid section (even without a starting
	107	point) it isn't a trampoline. */
	108	if (find_pc_section (pc) != NULL)
e2879ccb MK	109	return 0;
	110
	111	/* If we can't read the instructions at START_PC, return zero. */
4cd28409	112	buf = alloca ((sizeof sigreturn) + 1);
1c5bf419	113	if (!safe_frame_unwind_memory (next_frame, start_pc + 6, buf, buflen))
e2879ccb MK	114	return 0;
e2879ccb MK	115
4cd28409 MK	116	/* Check for sigreturn(2). Depending on how the assembler encoded
	117	the `movq %rsp, %rdi' instruction, the code starts at offset 6 or
	118	7. */
	119	if (memcmp (buf, sigreturn, sizeof sigreturn)
	120	&& memcpy (buf + 1, sigreturn, sizeof sigreturn))
e2879ccb MK	121	return 0;
	122
	123	return 1;
	124	}
	125
	126	/* Assuming NEXT_FRAME is for a frame following a BSD sigtramp
	127	routine, return the address of the associated sigcontext structure. */
	128
	129	static CORE_ADDR
	130	amd64obsd_sigcontext_addr (struct frame_info *next_frame)
	131	{
0fe85704 MK	132	CORE_ADDR pc = frame_pc_unwind (next_frame);
	133	ULONGEST offset = (pc & (amd64obsd_page_size - 1));
	134
e2879ccb	135	/* The %rsp register points at `struct sigcontext' upon entry of a
0fe85704 MK	136	signal trampoline. The relevant part of the trampoline is
	137
	138	call *%rax
	139	movq %rsp, %rdi
	140	pushq %rdi
	141	movq $SYS_sigreturn,%rax
	142	int $0x80
	143
	144	(see /usr/src/sys/arch/amd64/amd64/locore.S). The `pushq'
	145	instruction clobbers %rsp, but its value is saved in `%rdi'. */
	146
4cd28409	147	if (offset > 5)
0fe85704 MK	148	return frame_unwind_register_unsigned (next_frame, AMD64_RDI_REGNUM);
	149	else
	150	return frame_unwind_register_unsigned (next_frame, AMD64_RSP_REGNUM);
e2879ccb MK	151	}
	152	\f
	153	/* OpenBSD 3.5 or later. */
	154
	155	/* Mapping between the general-purpose registers in `struct reg'
	156	format and GDB's register cache layout. */
	157
30b344b1	158	/* From <machine/reg.h>. */
e2879ccb MK	159	int amd64obsd_r_reg_offset[] =
	160	{
	161	14 * 8, /* %rax */
	162	13 * 8, /* %rbx */
	163	3 * 8, /* %rcx */
	164	2 * 8, /* %rdx */
	165	1 * 8, /* %rsi */
	166	0 * 8, /* %rdi */
	167	12 * 8, /* %rbp */
	168	15 * 8, /* %rsp */
	169	4 * 8, /* %r8 .. */
	170	5 * 8,
	171	6 * 8,
	172	7 * 8,
	173	8 * 8,
	174	9 * 8,
	175	10 * 8,
	176	11 * 8, /* ... %r15 */
	177	16 * 8, /* %rip */
	178	17 * 8, /* %eflags */
	179	18 * 8, /* %cs */
	180	19 * 8, /* %ss */
	181	20 * 8, /* %ds */
	182	21 * 8, /* %es */
	183	22 * 8, /* %fs */
	184	23 * 8 /* %gs */
	185	};
	186
30b344b1	187	/* From <machine/signal.h>. */
e2879ccb MK	188	static int amd64obsd_sc_reg_offset[] =
	189	{
	190	14 * 8, /* %rax */
	191	13 * 8, /* %rbx */
	192	3 * 8, /* %rcx */
	193	2 * 8, /* %rdx */
	194	1 * 8, /* %rsi */
	195	0 * 8, /* %rdi */
	196	12 * 8, /* %rbp */
	197	24 * 8, /* %rsp */
	198	4 * 8, /* %r8 ... */
	199	5 * 8,
	200	6 * 8,
	201	7 * 8,
	202	8 * 8,
	203	9 * 8,
	204	10 * 8,
	205	11 * 8, /* ... %r15 */
	206	21 * 8, /* %rip */
	207	23 * 8, /* %eflags */
	208	22 * 8, /* %cs */
	209	25 * 8, /* %ss */
	210	18 * 8, /* %ds */
	211	17 * 8, /* %es */
	212	16 * 8, /* %fs */
	213	15 * 8 /* %gs */
	214	};
	215
d78749b4 MK	216	/* From /usr/src/lib/libpthread/arch/amd64/uthread_machdep.c. */
	217	static int amd64obsd_uthread_reg_offset[] =
	218	{
	219	19 * 8, /* %rax */
	220	16 * 8, /* %rbx */
	221	18 * 8, /* %rcx */
	222	17 * 8, /* %rdx */
	223	14 * 8, /* %rsi */
	224	13 * 8, /* %rdi */
	225	15 * 8, /* %rbp */
	226	-1, /* %rsp */
	227	12 * 8, /* %r8 ... */
	228	11 * 8,
	229	10 * 8,
	230	9 * 8,
	231	8 * 8,
	232	7 * 8,
	233	6 * 8,
	234	5 * 8, /* ... %r15 */
	235	20 * 8, /* %rip */
	236	4 * 8, /* %eflags */
	237	21 * 8, /* %cs */
	238	-1, /* %ss */
	239	3 * 8, /* %ds */
	240	2 * 8, /* %es */
	241	1 * 8, /* %fs */
	242	0 * 8 /* %gs */
	243	};
	244
	245	/* Offset within the thread structure where we can find the saved
	246	stack pointer (%esp). */
	247	#define AMD64OBSD_UTHREAD_RSP_OFFSET 400
	248
	249	static void
	250	amd64obsd_supply_uthread (struct regcache *regcache,
	251	int regnum, CORE_ADDR addr)
	252	{
	253	CORE_ADDR sp_addr = addr + AMD64OBSD_UTHREAD_RSP_OFFSET;
	254	CORE_ADDR sp = 0;
	255	gdb_byte buf[8];
	256	int i;
	257
	258	gdb_assert (regnum >= -1);
	259
	260	if (regnum == -1 \|\| regnum == AMD64_RSP_REGNUM)
	261	{
	262	int offset;
	263
	264	/* Fetch stack pointer from thread structure. */
	265	sp = read_memory_unsigned_integer (sp_addr, 8);
	266
	267	/* Adjust the stack pointer such that it looks as if we just
	268	returned from _thread_machdep_switch. */
	269	offset = amd64obsd_uthread_reg_offset[AMD64_RIP_REGNUM] + 8;
	270	store_unsigned_integer (buf, 8, sp + offset);
	271	regcache_raw_supply (regcache, AMD64_RSP_REGNUM, buf);
	272	}
	273
	274	for (i = 0; i < ARRAY_SIZE (amd64obsd_uthread_reg_offset); i++)
	275	{
	276	if (amd64obsd_uthread_reg_offset[i] != -1
	277	&& (regnum == -1 \|\| regnum == i))
	278	{
	279	/* Fetch stack pointer from thread structure (if we didn't
280	do so already). */
281	if (sp == 0)
282	sp = read_memory_unsigned_integer (sp_addr, 8);
283
284	/* Read the saved register from the stack frame. */
285	read_memory (sp + amd64obsd_uthread_reg_offset[i], buf, 8);
286	regcache_raw_supply (regcache, i, buf);
287	}
288	}
289	}
290
291	static void
292	amd64obsd_collect_uthread (const struct regcache *regcache,
293	int regnum, CORE_ADDR addr)
294	{
295	CORE_ADDR sp_addr = addr + AMD64OBSD_UTHREAD_RSP_OFFSET;
296	CORE_ADDR sp = 0;
297	gdb_byte buf[8];
298	int i;
299
300	gdb_assert (regnum >= -1);
301
302	if (regnum == -1 \|\| regnum == AMD64_RSP_REGNUM)
303	{
304	int offset;
305
306	/* Calculate the stack pointer (frame pointer) that will be
307	stored into the thread structure. */
308	offset = amd64obsd_uthread_reg_offset[AMD64_RIP_REGNUM] + 8;
309	regcache_raw_collect (regcache, AMD64_RSP_REGNUM, buf);
310	sp = extract_unsigned_integer (buf, 8) - offset;
311
312	/* Store the stack pointer. */
313	write_memory_unsigned_integer (sp_addr, 8, sp);
314
315	/* The stack pointer was (potentially) modified. Make sure we
316	build a proper stack frame. */
317	regnum = -1;
318	}
319
320	for (i = 0; i < ARRAY_SIZE (amd64obsd_uthread_reg_offset); i++)
321	{
322	if (amd64obsd_uthread_reg_offset[i] != -1
323	&& (regnum == -1 \|\| regnum == i))
324	{
325	/* Fetch stack pointer from thread structure (if we didn't
326	calculate it already). */
327	if (sp == 0)
328	sp = read_memory_unsigned_integer (sp_addr, 8);
329
330	/* Write the register into the stack frame. */
331	regcache_raw_collect (regcache, i, buf);
332	write_memory (sp + amd64obsd_uthread_reg_offset[i], buf, 8);
333	}
334	}
335	}
336
e2879ccb MK	337	static void
	338	amd64obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
	339	{
	340	struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
	341
90f90721	342	amd64_init_abi (info, gdbarch);
e2879ccb	343
30b344b1 MK	344	/* Initialize general-purpose register set details. */
	345	tdep->gregset_reg_offset = amd64obsd_r_reg_offset;
	346	tdep->gregset_num_regs = ARRAY_SIZE (amd64obsd_r_reg_offset);
	347	tdep->sizeof_gregset = 24 * 8;
	348
	349	set_gdbarch_regset_from_core_section (gdbarch,
	350	amd64obsd_regset_from_core_section);
	351
e2879ccb MK	352	tdep->jb_pc_offset = 7 * 8;
e2879ccb MK	353
911bc6ee	354	tdep->sigtramp_p = amd64obsd_sigtramp_p;
e2879ccb MK	355	tdep->sigcontext_addr = amd64obsd_sigcontext_addr;
	356	tdep->sc_reg_offset = amd64obsd_sc_reg_offset;
	357	tdep->sc_num_regs = ARRAY_SIZE (amd64obsd_sc_reg_offset);
7e654c37	358
d78749b4 MK	359	/* OpenBSD provides a user-level threads implementation. */
	360	bsd_uthread_set_supply_uthread (gdbarch, amd64obsd_supply_uthread);
	361	bsd_uthread_set_collect_uthread (gdbarch, amd64obsd_collect_uthread);
	362
7e654c37 MK	363	/* OpenBSD uses SVR4-style shared libraries. */
	364	set_solib_svr4_fetch_link_map_offsets
	365	(gdbarch, svr4_lp64_fetch_link_map_offsets);
e2879ccb MK	366	}
	367	\f
	368
	369	/* Provide a prototype to silence -Wmissing-prototypes. */
	370	void _initialize_amd64obsd_tdep (void);
	371
	372	void
30b344b1	373	_initialize_amd64obsd_tdep (void)
e2879ccb MK	374	{
e2879ccb MK	375	/* The OpenBSD/amd64 native dependent code makes this assumption. */
90f90721	376	gdb_assert (ARRAY_SIZE (amd64obsd_r_reg_offset) == AMD64_NUM_GREGS);
e2879ccb MK	377
	378	gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64,
	379	GDB_OSABI_OPENBSD_ELF, amd64obsd_init_abi);
30b344b1 MK	380
	381	/* OpenBSD uses traditional (a.out) NetBSD-style core dumps. */
	382	gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64,
	383	GDB_OSABI_NETBSD_AOUT, amd64obsd_init_abi);
e2879ccb	384	}