489 lines
14 KiB
C
489 lines
14 KiB
C
/* Target-dependent code for FreeBSD/i386.
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Copyright (C) 2003-2017 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 3 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, see <http://www.gnu.org/licenses/>. */
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#include "defs.h"
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#include "arch-utils.h"
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#include "gdbcore.h"
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#include "osabi.h"
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#include "regcache.h"
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#include "regset.h"
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#include "i386-fbsd-tdep.h"
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#include "x86-xstate.h"
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#include "i386-tdep.h"
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#include "i387-tdep.h"
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#include "bsd-uthread.h"
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#include "fbsd-tdep.h"
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#include "solib-svr4.h"
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/* Support for signal handlers. */
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/* Return whether THIS_FRAME corresponds to a FreeBSD sigtramp
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routine. */
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/* FreeBSD/i386 supports three different signal trampolines, one for
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versions before 4.0, a second for 4.x, and a third for 5.0 and
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later. To complicate matters, FreeBSD/i386 binaries running under
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an amd64 kernel use a different set of trampolines. These
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trampolines differ from the i386 kernel trampolines in that they
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omit a middle section that conditionally restores %gs. */
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static const gdb_byte i386fbsd_sigtramp_start[] =
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{
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0x8d, 0x44, 0x24, 0x20, /* lea SIGF_UC(%esp),%eax */
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0x50 /* pushl %eax */
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};
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static const gdb_byte i386fbsd_sigtramp_middle[] =
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{
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0xf7, 0x40, 0x54, 0x00, 0x00, 0x02, 0x00,
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/* testl $PSL_VM,UC_EFLAGS(%eax) */
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0x75, 0x03, /* jne +3 */
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0x8e, 0x68, 0x14 /* mov UC_GS(%eax),%gs */
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};
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static const gdb_byte i386fbsd_sigtramp_end[] =
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{
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0xb8, 0xa1, 0x01, 0x00, 0x00, /* movl $SYS_sigreturn,%eax */
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0x50, /* pushl %eax */
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0xcd, 0x80 /* int $0x80 */
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};
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static const gdb_byte i386fbsd_freebsd4_sigtramp_start[] =
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{
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0x8d, 0x44, 0x24, 0x14, /* lea SIGF_UC4(%esp),%eax */
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0x50 /* pushl %eax */
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};
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static const gdb_byte i386fbsd_freebsd4_sigtramp_middle[] =
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{
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0xf7, 0x40, 0x54, 0x00, 0x00, 0x02, 0x00,
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/* testl $PSL_VM,UC4_EFLAGS(%eax) */
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0x75, 0x03, /* jne +3 */
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0x8e, 0x68, 0x14 /* mov UC4_GS(%eax),%gs */
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};
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static const gdb_byte i386fbsd_freebsd4_sigtramp_end[] =
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{
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0xb8, 0x58, 0x01, 0x00, 0x00, /* movl $344,%eax */
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0x50, /* pushl %eax */
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0xcd, 0x80 /* int $0x80 */
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};
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static const gdb_byte i386fbsd_osigtramp_start[] =
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{
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0x8d, 0x44, 0x24, 0x14, /* lea SIGF_SC(%esp),%eax */
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0x50 /* pushl %eax */
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};
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static const gdb_byte i386fbsd_osigtramp_middle[] =
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{
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0xf7, 0x40, 0x18, 0x00, 0x00, 0x02, 0x00,
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/* testl $PSL_VM,SC_PS(%eax) */
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0x75, 0x03, /* jne +3 */
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0x8e, 0x68, 0x44 /* mov SC_GS(%eax),%gs */
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};
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static const gdb_byte i386fbsd_osigtramp_end[] =
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{
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0xb8, 0x67, 0x00, 0x00, 0x00, /* movl $103,%eax */
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0x50, /* pushl %eax */
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0xcd, 0x80 /* int $0x80 */
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};
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/* The three different trampolines are all the same size. */
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gdb_static_assert (sizeof i386fbsd_sigtramp_start
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== sizeof i386fbsd_freebsd4_sigtramp_start);
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gdb_static_assert (sizeof i386fbsd_sigtramp_start
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== sizeof i386fbsd_osigtramp_start);
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gdb_static_assert (sizeof i386fbsd_sigtramp_middle
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== sizeof i386fbsd_freebsd4_sigtramp_middle);
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gdb_static_assert (sizeof i386fbsd_sigtramp_middle
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== sizeof i386fbsd_osigtramp_middle);
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gdb_static_assert (sizeof i386fbsd_sigtramp_end
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== sizeof i386fbsd_freebsd4_sigtramp_end);
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gdb_static_assert (sizeof i386fbsd_sigtramp_end
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== sizeof i386fbsd_osigtramp_end);
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/* We assume that the middle is the largest chunk below. */
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gdb_static_assert (sizeof i386fbsd_sigtramp_middle
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> sizeof i386fbsd_sigtramp_start);
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gdb_static_assert (sizeof i386fbsd_sigtramp_middle
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> sizeof i386fbsd_sigtramp_end);
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static int
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i386fbsd_sigtramp_p (struct frame_info *this_frame)
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{
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CORE_ADDR pc = get_frame_pc (this_frame);
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gdb_byte buf[sizeof i386fbsd_sigtramp_middle];
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const gdb_byte *middle, *end;
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/* Look for a matching start. */
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if (!safe_frame_unwind_memory (this_frame, pc, buf,
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sizeof i386fbsd_sigtramp_start))
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return 0;
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if (memcmp (buf, i386fbsd_sigtramp_start, sizeof i386fbsd_sigtramp_start)
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== 0)
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{
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middle = i386fbsd_sigtramp_middle;
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end = i386fbsd_sigtramp_end;
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}
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else if (memcmp (buf, i386fbsd_freebsd4_sigtramp_start,
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sizeof i386fbsd_freebsd4_sigtramp_start) == 0)
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{
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middle = i386fbsd_freebsd4_sigtramp_middle;
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end = i386fbsd_freebsd4_sigtramp_end;
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}
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else if (memcmp (buf, i386fbsd_osigtramp_start,
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sizeof i386fbsd_osigtramp_start) == 0)
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{
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middle = i386fbsd_osigtramp_middle;
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end = i386fbsd_osigtramp_end;
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}
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else
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return 0;
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/* Since the end is shorter than the middle, check for a matching end
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next. */
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pc += sizeof i386fbsd_sigtramp_start;
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if (!safe_frame_unwind_memory (this_frame, pc, buf,
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sizeof i386fbsd_sigtramp_end))
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return 0;
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if (memcmp (buf, end, sizeof i386fbsd_sigtramp_end) == 0)
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return 1;
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/* If the end didn't match, check for a matching middle. */
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if (!safe_frame_unwind_memory (this_frame, pc, buf,
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sizeof i386fbsd_sigtramp_middle))
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return 0;
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if (memcmp (buf, middle, sizeof i386fbsd_sigtramp_middle) != 0)
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return 0;
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/* The middle matched, check for a matching end. */
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pc += sizeof i386fbsd_sigtramp_middle;
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if (!safe_frame_unwind_memory (this_frame, pc, buf,
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sizeof i386fbsd_sigtramp_end))
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return 0;
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if (memcmp (buf, end, sizeof i386fbsd_sigtramp_end) != 0)
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return 0;
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return 1;
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}
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/* FreeBSD 3.0-RELEASE or later. */
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/* From <machine/reg.h>. */
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static int i386fbsd_r_reg_offset[] =
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{
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9 * 4, 8 * 4, 7 * 4, 6 * 4, /* %eax, %ecx, %edx, %ebx */
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15 * 4, 4 * 4, /* %esp, %ebp */
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3 * 4, 2 * 4, /* %esi, %edi */
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12 * 4, 14 * 4, /* %eip, %eflags */
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13 * 4, 16 * 4, /* %cs, %ss */
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1 * 4, 0 * 4, -1, -1 /* %ds, %es, %fs, %gs */
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};
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/* Sigtramp routine location. */
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CORE_ADDR i386fbsd_sigtramp_start_addr;
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CORE_ADDR i386fbsd_sigtramp_end_addr;
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/* From <machine/signal.h>. */
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int i386fbsd_sc_reg_offset[] =
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{
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8 + 14 * 4, /* %eax */
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8 + 13 * 4, /* %ecx */
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8 + 12 * 4, /* %edx */
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8 + 11 * 4, /* %ebx */
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8 + 0 * 4, /* %esp */
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8 + 1 * 4, /* %ebp */
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8 + 10 * 4, /* %esi */
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8 + 9 * 4, /* %edi */
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8 + 3 * 4, /* %eip */
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8 + 4 * 4, /* %eflags */
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8 + 7 * 4, /* %cs */
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8 + 8 * 4, /* %ss */
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8 + 6 * 4, /* %ds */
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8 + 5 * 4, /* %es */
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8 + 15 * 4, /* %fs */
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8 + 16 * 4 /* %gs */
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};
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/* From /usr/src/lib/libc/i386/gen/_setjmp.S. */
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static int i386fbsd_jmp_buf_reg_offset[] =
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{
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-1, /* %eax */
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-1, /* %ecx */
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-1, /* %edx */
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1 * 4, /* %ebx */
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2 * 4, /* %esp */
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3 * 4, /* %ebp */
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4 * 4, /* %esi */
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5 * 4, /* %edi */
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0 * 4 /* %eip */
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};
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/* Get XSAVE extended state xcr0 from core dump. */
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uint64_t
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i386fbsd_core_read_xcr0 (bfd *abfd)
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{
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asection *xstate = bfd_get_section_by_name (abfd, ".reg-xstate");
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uint64_t xcr0;
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if (xstate)
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{
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size_t size = bfd_section_size (abfd, xstate);
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/* Check extended state size. */
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if (size < X86_XSTATE_AVX_SIZE)
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xcr0 = X86_XSTATE_SSE_MASK;
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else
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{
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char contents[8];
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if (! bfd_get_section_contents (abfd, xstate, contents,
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I386_FBSD_XSAVE_XCR0_OFFSET,
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8))
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{
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warning (_("Couldn't read `xcr0' bytes from "
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"`.reg-xstate' section in core file."));
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return 0;
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}
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xcr0 = bfd_get_64 (abfd, contents);
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}
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}
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else
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xcr0 = 0;
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return xcr0;
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}
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/* Implement the core_read_description gdbarch method. */
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static const struct target_desc *
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i386fbsd_core_read_description (struct gdbarch *gdbarch,
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struct target_ops *target,
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bfd *abfd)
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{
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return i386_target_description (i386fbsd_core_read_xcr0 (abfd));
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}
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/* Similar to i386_supply_fpregset, but use XSAVE extended state. */
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static void
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i386fbsd_supply_xstateregset (const struct regset *regset,
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struct regcache *regcache, int regnum,
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const void *xstateregs, size_t len)
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{
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i387_supply_xsave (regcache, regnum, xstateregs);
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}
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/* Similar to i386_collect_fpregset, but use XSAVE extended state. */
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static void
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i386fbsd_collect_xstateregset (const struct regset *regset,
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const struct regcache *regcache,
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int regnum, void *xstateregs, size_t len)
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{
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i387_collect_xsave (regcache, regnum, xstateregs, 1);
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}
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/* Register set definitions. */
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static const struct regset i386fbsd_xstateregset =
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{
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NULL,
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i386fbsd_supply_xstateregset,
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i386fbsd_collect_xstateregset
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};
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/* Iterate over core file register note sections. */
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static void
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i386fbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
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iterate_over_regset_sections_cb *cb,
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void *cb_data,
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const struct regcache *regcache)
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{
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struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
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cb (".reg", tdep->sizeof_gregset, &i386_gregset, NULL, cb_data);
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cb (".reg2", tdep->sizeof_fpregset, &i386_fpregset, NULL, cb_data);
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if (tdep->xcr0 & X86_XSTATE_AVX)
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cb (".reg-xstate", X86_XSTATE_SIZE(tdep->xcr0),
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&i386fbsd_xstateregset, "XSAVE extended state", cb_data);
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}
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static void
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i386fbsd_supply_uthread (struct regcache *regcache,
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int regnum, CORE_ADDR addr)
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{
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gdb_byte buf[4];
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int i;
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gdb_assert (regnum >= -1);
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for (i = 0; i < ARRAY_SIZE (i386fbsd_jmp_buf_reg_offset); i++)
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{
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if (i386fbsd_jmp_buf_reg_offset[i] != -1
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&& (regnum == -1 || regnum == i))
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{
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read_memory (addr + i386fbsd_jmp_buf_reg_offset[i], buf, 4);
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regcache_raw_supply (regcache, i, buf);
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}
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}
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}
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static void
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i386fbsd_collect_uthread (const struct regcache *regcache,
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int regnum, CORE_ADDR addr)
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{
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gdb_byte buf[4];
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int i;
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gdb_assert (regnum >= -1);
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for (i = 0; i < ARRAY_SIZE (i386fbsd_jmp_buf_reg_offset); i++)
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{
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if (i386fbsd_jmp_buf_reg_offset[i] != -1
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&& (regnum == -1 || regnum == i))
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{
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regcache_raw_collect (regcache, i, buf);
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write_memory (addr + i386fbsd_jmp_buf_reg_offset[i], buf, 4);
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}
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}
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}
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static void
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i386fbsd_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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/* Obviously FreeBSD is BSD-based. */
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i386bsd_init_abi (info, gdbarch);
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/* FreeBSD has a different `struct reg', and reserves some space for
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its FPU emulator in `struct fpreg'. */
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tdep->gregset_reg_offset = i386fbsd_r_reg_offset;
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tdep->gregset_num_regs = ARRAY_SIZE (i386fbsd_r_reg_offset);
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tdep->sizeof_gregset = 18 * 4;
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tdep->sizeof_fpregset = 176;
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/* FreeBSD uses -freg-struct-return by default. */
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tdep->struct_return = reg_struct_return;
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tdep->sigtramp_p = i386fbsd_sigtramp_p;
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/* FreeBSD uses a different memory layout. */
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tdep->sigtramp_start = i386fbsd_sigtramp_start_addr;
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tdep->sigtramp_end = i386fbsd_sigtramp_end_addr;
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/* FreeBSD has a more complete `struct sigcontext'. */
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tdep->sc_reg_offset = i386fbsd_sc_reg_offset;
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tdep->sc_num_regs = ARRAY_SIZE (i386fbsd_sc_reg_offset);
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/* FreeBSD provides a user-level threads implementation. */
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bsd_uthread_set_supply_uthread (gdbarch, i386fbsd_supply_uthread);
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bsd_uthread_set_collect_uthread (gdbarch, i386fbsd_collect_uthread);
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i386_elf_init_abi (info, gdbarch);
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/* FreeBSD uses SVR4-style shared libraries. */
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set_solib_svr4_fetch_link_map_offsets
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(gdbarch, svr4_ilp32_fetch_link_map_offsets);
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}
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/* FreeBSD 4.0-RELEASE or later. */
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/* From <machine/reg.h>. */
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static int i386fbsd4_r_reg_offset[] =
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{
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10 * 4, 9 * 4, 8 * 4, 7 * 4, /* %eax, %ecx, %edx, %ebx */
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16 * 4, 5 * 4, /* %esp, %ebp */
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4 * 4, 3 * 4, /* %esi, %edi */
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13 * 4, 15 * 4, /* %eip, %eflags */
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14 * 4, 17 * 4, /* %cs, %ss */
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2 * 4, 1 * 4, 0 * 4, 18 * 4 /* %ds, %es, %fs, %gs */
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};
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/* From <machine/signal.h>. */
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int i386fbsd4_sc_reg_offset[] =
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{
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20 + 11 * 4, /* %eax */
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20 + 10 * 4, /* %ecx */
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20 + 9 * 4, /* %edx */
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20 + 8 * 4, /* %ebx */
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20 + 17 * 4, /* %esp */
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20 + 6 * 4, /* %ebp */
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20 + 5 * 4, /* %esi */
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20 + 4 * 4, /* %edi */
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20 + 14 * 4, /* %eip */
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20 + 16 * 4, /* %eflags */
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20 + 15 * 4, /* %cs */
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20 + 18 * 4, /* %ss */
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20 + 3 * 4, /* %ds */
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20 + 2 * 4, /* %es */
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20 + 1 * 4, /* %fs */
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20 + 0 * 4 /* %gs */
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};
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static void
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i386fbsd4_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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/* Generic FreeBSD support. */
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fbsd_init_abi (info, gdbarch);
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/* Inherit stuff from older releases. We assume that FreeBSD
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4.0-RELEASE always uses ELF. */
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i386fbsd_init_abi (info, gdbarch);
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/* FreeBSD 4.0 introduced a new `struct reg'. */
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tdep->gregset_reg_offset = i386fbsd4_r_reg_offset;
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tdep->gregset_num_regs = ARRAY_SIZE (i386fbsd4_r_reg_offset);
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tdep->sizeof_gregset = 19 * 4;
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/* FreeBSD 4.0 introduced a new `struct sigcontext'. */
|
||
tdep->sc_reg_offset = i386fbsd4_sc_reg_offset;
|
||
tdep->sc_num_regs = ARRAY_SIZE (i386fbsd4_sc_reg_offset);
|
||
|
||
tdep->xsave_xcr0_offset = I386_FBSD_XSAVE_XCR0_OFFSET;
|
||
|
||
/* Iterate over core file register note sections. */
|
||
set_gdbarch_iterate_over_regset_sections
|
||
(gdbarch, i386fbsd_iterate_over_regset_sections);
|
||
|
||
set_gdbarch_core_read_description (gdbarch,
|
||
i386fbsd_core_read_description);
|
||
}
|
||
|
||
|
||
/* Provide a prototype to silence -Wmissing-prototypes. */
|
||
void _initialize_i386fbsd_tdep (void);
|
||
|
||
void
|
||
_initialize_i386fbsd_tdep (void)
|
||
{
|
||
gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_FREEBSD,
|
||
i386fbsd4_init_abi);
|
||
}
|