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/* Target-dependent code for OpenBSD/amd64.
Copyright 2003, 2004 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 "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"
/* 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, (char *)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;
}
/* 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 char sigreturn[] =
{
0x48, 0xc7, 0xc0,
0x67, 0x00, 0x00, 0x00, /* movq $SYS_sigreturn, %rax */
0xcd, 0x80 /* int $0x80 */
};
size_t buflen = (sizeof sigreturn) + 1;
char *name, *buf;
/* 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);
}
/* 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 */
};
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 uses SVR4-style shared libraries. */
set_solib_svr4_fetch_link_map_offsets
(gdbarch, svr4_lp64_fetch_link_map_offsets);
}
/* 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);
}
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