255 lines
7 KiB
C
255 lines
7 KiB
C
/* Target-dependent code for OpenBSD/amd64.
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Copyright 2003, 2004 Free Software Foundation, Inc.
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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 "frame.h"
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#include "gdbcore.h"
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#include "symtab.h"
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#include "objfiles.h"
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#include "osabi.h"
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#include "regset.h"
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#include "target.h"
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#include "gdb_assert.h"
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#include "gdb_string.h"
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#include "amd64-tdep.h"
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#include "i387-tdep.h"
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#include "solib-svr4.h"
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/* Support for core dumps. */
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static void
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amd64obsd_supply_regset (const struct regset *regset,
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struct regcache *regcache, int regnum,
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const void *regs, size_t len)
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{
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const struct gdbarch_tdep *tdep = gdbarch_tdep (regset->arch);
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gdb_assert (len >= tdep->sizeof_gregset + I387_SIZEOF_FXSAVE);
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i386_supply_gregset (regset, regcache, regnum, regs, tdep->sizeof_gregset);
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amd64_supply_fxsave (regcache, regnum, (char *)regs + tdep->sizeof_gregset);
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}
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static const struct regset *
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amd64obsd_regset_from_core_section (struct gdbarch *gdbarch,
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const char *sect_name, size_t sect_size)
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{
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struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
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/* OpenBSD core dumps don't use seperate register sets for the
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general-purpose and floating-point registers. */
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if (strcmp (sect_name, ".reg") == 0
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&& sect_size >= tdep->sizeof_gregset + I387_SIZEOF_FXSAVE)
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{
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if (tdep->gregset == NULL)
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tdep->gregset = regset_alloc (gdbarch, amd64obsd_supply_regset, NULL);
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return tdep->gregset;
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}
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return NULL;
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}
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/* Support for signal handlers. */
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/* Default page size. */
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static const int amd64obsd_page_size = 4096;
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/* Return whether the frame preceding NEXT_FRAME corresponds to an
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OpenBSD sigtramp routine. */
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static int
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amd64obsd_sigtramp_p (struct frame_info *next_frame)
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{
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CORE_ADDR pc = frame_pc_unwind (next_frame);
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CORE_ADDR start_pc = (pc & ~(amd64obsd_page_size - 1));
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const char sigreturn[] =
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{
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0x48, 0xc7, 0xc0,
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0x67, 0x00, 0x00, 0x00, /* movq $SYS_sigreturn, %rax */
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0xcd, 0x80 /* int $0x80 */
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};
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size_t buflen = (sizeof sigreturn) + 1;
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char *name, *buf;
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/* If the function has a valid symbol name, it isn't a
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trampoline. */
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find_pc_partial_function (pc, &name, NULL, NULL);
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if (name != NULL)
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return 0;
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/* If the function lives in a valid section (even without a starting
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point) it isn't a trampoline. */
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if (find_pc_section (pc) != NULL)
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return 0;
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/* If we can't read the instructions at START_PC, return zero. */
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buf = alloca ((sizeof sigreturn) + 1);
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if (!safe_frame_unwind_memory (next_frame, start_pc + 6, buf, buflen))
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return 0;
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/* Check for sigreturn(2). Depending on how the assembler encoded
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the `movq %rsp, %rdi' instruction, the code starts at offset 6 or
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7. */
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if (memcmp (buf, sigreturn, sizeof sigreturn)
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&& memcpy (buf + 1, sigreturn, sizeof sigreturn))
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return 0;
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return 1;
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}
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/* Assuming NEXT_FRAME is for a frame following a BSD 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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amd64obsd_sigcontext_addr (struct frame_info *next_frame)
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{
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CORE_ADDR pc = frame_pc_unwind (next_frame);
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ULONGEST offset = (pc & (amd64obsd_page_size - 1));
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/* The %rsp register points at `struct sigcontext' upon entry of a
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signal trampoline. The relevant part of the trampoline is
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call *%rax
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movq %rsp, %rdi
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pushq %rdi
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movq $SYS_sigreturn,%rax
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int $0x80
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(see /usr/src/sys/arch/amd64/amd64/locore.S). The `pushq'
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instruction clobbers %rsp, but its value is saved in `%rdi'. */
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if (offset > 5)
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return frame_unwind_register_unsigned (next_frame, AMD64_RDI_REGNUM);
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else
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return frame_unwind_register_unsigned (next_frame, AMD64_RSP_REGNUM);
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}
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/* OpenBSD 3.5 or later. */
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/* Mapping between the general-purpose registers in `struct reg'
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format and GDB's register cache layout. */
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/* From <machine/reg.h>. */
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int amd64obsd_r_reg_offset[] =
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{
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14 * 8, /* %rax */
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13 * 8, /* %rbx */
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3 * 8, /* %rcx */
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2 * 8, /* %rdx */
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1 * 8, /* %rsi */
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0 * 8, /* %rdi */
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12 * 8, /* %rbp */
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15 * 8, /* %rsp */
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4 * 8, /* %r8 .. */
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5 * 8,
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6 * 8,
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7 * 8,
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8 * 8,
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9 * 8,
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10 * 8,
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11 * 8, /* ... %r15 */
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16 * 8, /* %rip */
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17 * 8, /* %eflags */
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18 * 8, /* %cs */
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19 * 8, /* %ss */
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20 * 8, /* %ds */
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21 * 8, /* %es */
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22 * 8, /* %fs */
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23 * 8 /* %gs */
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};
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/* From <machine/signal.h>. */
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static int amd64obsd_sc_reg_offset[] =
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{
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14 * 8, /* %rax */
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13 * 8, /* %rbx */
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3 * 8, /* %rcx */
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2 * 8, /* %rdx */
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1 * 8, /* %rsi */
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0 * 8, /* %rdi */
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12 * 8, /* %rbp */
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24 * 8, /* %rsp */
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4 * 8, /* %r8 ... */
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5 * 8,
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6 * 8,
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7 * 8,
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8 * 8,
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9 * 8,
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10 * 8,
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11 * 8, /* ... %r15 */
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21 * 8, /* %rip */
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23 * 8, /* %eflags */
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22 * 8, /* %cs */
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25 * 8, /* %ss */
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18 * 8, /* %ds */
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17 * 8, /* %es */
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16 * 8, /* %fs */
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15 * 8 /* %gs */
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};
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static void
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amd64obsd_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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amd64_init_abi (info, gdbarch);
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/* Initialize general-purpose register set details. */
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tdep->gregset_reg_offset = amd64obsd_r_reg_offset;
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tdep->gregset_num_regs = ARRAY_SIZE (amd64obsd_r_reg_offset);
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tdep->sizeof_gregset = 24 * 8;
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set_gdbarch_regset_from_core_section (gdbarch,
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amd64obsd_regset_from_core_section);
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tdep->jb_pc_offset = 7 * 8;
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tdep->sigtramp_p = amd64obsd_sigtramp_p;
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tdep->sigcontext_addr = amd64obsd_sigcontext_addr;
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tdep->sc_reg_offset = amd64obsd_sc_reg_offset;
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tdep->sc_num_regs = ARRAY_SIZE (amd64obsd_sc_reg_offset);
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/* OpenBSD uses SVR4-style shared libraries. */
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set_solib_svr4_fetch_link_map_offsets
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(gdbarch, svr4_lp64_fetch_link_map_offsets);
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}
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/* Provide a prototype to silence -Wmissing-prototypes. */
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void _initialize_amd64obsd_tdep (void);
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void
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_initialize_amd64obsd_tdep (void)
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{
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/* The OpenBSD/amd64 native dependent code makes this assumption. */
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gdb_assert (ARRAY_SIZE (amd64obsd_r_reg_offset) == AMD64_NUM_GREGS);
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gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64,
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GDB_OSABI_OPENBSD_ELF, amd64obsd_init_abi);
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/* OpenBSD uses traditional (a.out) NetBSD-style core dumps. */
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gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64,
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GDB_OSABI_NETBSD_AOUT, amd64obsd_init_abi);
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}
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