/* Target-dependent code for FreeBSD/i386.
- Copyright (C) 2003, 2004, 2005 Free Software Foundation, Inc.
+ Copyright (C) 2003-2015 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
+ the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
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., 51 Franklin Street, Fifth Floor,
- Boston, MA 02110-1301, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "arch-utils.h"
#include "osabi.h"
#include "regcache.h"
-#include "gdb_assert.h"
-
#include "i386-tdep.h"
#include "i387-tdep.h"
#include "bsd-uthread.h"
+#include "fbsd-tdep.h"
#include "solib-svr4.h"
+/* Support for signal handlers. */
+
+/* Return whether THIS_FRAME corresponds to a FreeBSD sigtramp
+ routine. */
+
+/* FreeBSD/i386 supports three different signal trampolines, one for
+ versions before 4.0, a second for 4.x, and a third for 5.0 and
+ later. To complicate matters, FreeBSD/i386 binaries running under
+ an amd64 kernel use a different set of trampolines. These
+ trampolines differ from the i386 kernel trampolines in that they
+ omit a middle section that conditionally restores %gs. */
+
+static const gdb_byte i386fbsd_sigtramp_start[] =
+{
+ 0x8d, 0x44, 0x24, 0x20, /* lea SIGF_UC(%esp),%eax */
+ 0x50 /* pushl %eax */
+};
+
+static const gdb_byte i386fbsd_sigtramp_middle[] =
+{
+ 0xf7, 0x40, 0x54, 0x00, 0x00, 0x02, 0x00,
+ /* testl $PSL_VM,UC_EFLAGS(%eax) */
+ 0x75, 0x03, /* jne +3 */
+ 0x8e, 0x68, 0x14 /* mov UC_GS(%eax),%gs */
+};
+
+static const gdb_byte i386fbsd_sigtramp_end[] =
+{
+ 0xb8, 0xa1, 0x01, 0x00, 0x00, /* movl $SYS_sigreturn,%eax */
+ 0x50, /* pushl %eax */
+ 0xcd, 0x80 /* int $0x80 */
+};
+
+static const gdb_byte i386fbsd_freebsd4_sigtramp_start[] =
+{
+ 0x8d, 0x44, 0x24, 0x14, /* lea SIGF_UC4(%esp),%eax */
+ 0x50 /* pushl %eax */
+};
+
+static const gdb_byte i386fbsd_freebsd4_sigtramp_middle[] =
+{
+ 0xf7, 0x40, 0x54, 0x00, 0x00, 0x02, 0x00,
+ /* testl $PSL_VM,UC4_EFLAGS(%eax) */
+ 0x75, 0x03, /* jne +3 */
+ 0x8e, 0x68, 0x14 /* mov UC4_GS(%eax),%gs */
+};
+
+static const gdb_byte i386fbsd_freebsd4_sigtramp_end[] =
+{
+ 0xb8, 0x58, 0x01, 0x00, 0x00, /* movl $344,%eax */
+ 0x50, /* pushl %eax */
+ 0xcd, 0x80 /* int $0x80 */
+};
+
+static const gdb_byte i386fbsd_osigtramp_start[] =
+{
+ 0x8d, 0x44, 0x24, 0x14, /* lea SIGF_SC(%esp),%eax */
+ 0x50 /* pushl %eax */
+};
+
+static const gdb_byte i386fbsd_osigtramp_middle[] =
+{
+ 0xf7, 0x40, 0x18, 0x00, 0x00, 0x02, 0x00,
+ /* testl $PSL_VM,SC_PS(%eax) */
+ 0x75, 0x03, /* jne +3 */
+ 0x8e, 0x68, 0x44 /* mov SC_GS(%eax),%gs */
+};
+
+static const gdb_byte i386fbsd_osigtramp_end[] =
+{
+ 0xb8, 0x67, 0x00, 0x00, 0x00, /* movl $103,%eax */
+ 0x50, /* pushl %eax */
+ 0xcd, 0x80 /* int $0x80 */
+};
+
+/* The three different trampolines are all the same size. */
+gdb_static_assert (sizeof i386fbsd_sigtramp_start ==
+ sizeof i386fbsd_freebsd4_sigtramp_start);
+gdb_static_assert (sizeof i386fbsd_sigtramp_start ==
+ sizeof i386fbsd_osigtramp_start);
+gdb_static_assert (sizeof i386fbsd_sigtramp_middle ==
+ sizeof i386fbsd_freebsd4_sigtramp_middle);
+gdb_static_assert (sizeof i386fbsd_sigtramp_middle ==
+ sizeof i386fbsd_osigtramp_middle);
+gdb_static_assert (sizeof i386fbsd_sigtramp_end ==
+ sizeof i386fbsd_freebsd4_sigtramp_end);
+gdb_static_assert (sizeof i386fbsd_sigtramp_end ==
+ sizeof i386fbsd_osigtramp_end);
+
+/* We assume that the middle is the largest chunk below. */
+gdb_static_assert (sizeof i386fbsd_sigtramp_middle >
+ sizeof i386fbsd_sigtramp_start);
+gdb_static_assert (sizeof i386fbsd_sigtramp_middle >
+ sizeof i386fbsd_sigtramp_end);
+
+static int
+i386fbsd_sigtramp_p (struct frame_info *this_frame)
+{
+ CORE_ADDR pc = get_frame_pc (this_frame);
+ gdb_byte buf[sizeof i386fbsd_sigtramp_middle];
+ const gdb_byte *middle, *end;
+
+ /* Look for a matching start. */
+ if (!safe_frame_unwind_memory (this_frame, pc, buf,
+ sizeof i386fbsd_sigtramp_start))
+ return 0;
+ if (memcmp (buf, i386fbsd_sigtramp_start, sizeof i386fbsd_sigtramp_start) ==
+ 0) {
+ middle = i386fbsd_sigtramp_middle;
+ end = i386fbsd_sigtramp_end;
+ } else if (memcmp (buf, i386fbsd_freebsd4_sigtramp_start,
+ sizeof i386fbsd_freebsd4_sigtramp_start) == 0) {
+ middle = i386fbsd_freebsd4_sigtramp_middle;
+ end = i386fbsd_freebsd4_sigtramp_end;
+ } else if (memcmp (buf, i386fbsd_osigtramp_start,
+ sizeof i386fbsd_osigtramp_start) == 0) {
+ middle = i386fbsd_osigtramp_middle;
+ end = i386fbsd_osigtramp_end;
+ } else
+ return 0;
+
+ /* Since the end is shorter than the middle, check for a matching end
+ next. */
+ pc += sizeof i386fbsd_sigtramp_start;
+ if (!safe_frame_unwind_memory (this_frame, pc, buf,
+ sizeof i386fbsd_sigtramp_end))
+ return 0;
+ if (memcmp (buf, end, sizeof i386fbsd_sigtramp_end) == 0)
+ return 1;
+
+ /* If the end didn't match, check for a matching middle. */
+ if (!safe_frame_unwind_memory (this_frame, pc, buf,
+ sizeof i386fbsd_sigtramp_middle))
+ return 0;
+ if (memcmp (buf, middle, sizeof i386fbsd_sigtramp_middle) != 0)
+ return 0;
+
+ /* The middle matched, check for a matching end. */
+ pc += sizeof i386fbsd_sigtramp_middle;
+ if (!safe_frame_unwind_memory (this_frame, pc, buf,
+ sizeof i386fbsd_sigtramp_end))
+ return 0;
+ if (memcmp (buf, end, sizeof i386fbsd_sigtramp_end) != 0)
+ return 0;
+
+ return 1;
+}
+
/* FreeBSD 3.0-RELEASE or later. */
/* From <machine/reg.h>. */
};
/* Sigtramp routine location. */
-CORE_ADDR i386fbsd_sigtramp_start_addr = 0xbfbfdf20;
-CORE_ADDR i386fbsd_sigtramp_end_addr = 0xbfbfdff0;
+CORE_ADDR i386fbsd_sigtramp_start_addr;
+CORE_ADDR i386fbsd_sigtramp_end_addr;
/* From <machine/signal.h>. */
int i386fbsd_sc_reg_offset[] =
i386fbsd_supply_uthread (struct regcache *regcache,
int regnum, CORE_ADDR addr)
{
- char buf[4];
+ gdb_byte buf[4];
int i;
gdb_assert (regnum >= -1);
i386fbsd_collect_uthread (const struct regcache *regcache,
int regnum, CORE_ADDR addr)
{
- char buf[4];
+ gdb_byte buf[4];
int i;
gdb_assert (regnum >= -1);
/* FreeBSD uses -freg-struct-return by default. */
tdep->struct_return = reg_struct_return;
+ tdep->sigtramp_p = i386fbsd_sigtramp_p;
+
/* FreeBSD uses a different memory layout. */
tdep->sigtramp_start = i386fbsd_sigtramp_start_addr;
tdep->sigtramp_end = i386fbsd_sigtramp_end_addr;
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ /* Generic FreeBSD support. */
+ fbsd_init_abi (info, gdbarch);
+
/* Inherit stuff from older releases. We assume that FreeBSD
4.0-RELEASE always uses ELF. */
i386fbsd_init_abi (info, gdbarch);