/* Target-dependent code for FreeBSD/i386.
- Copyright (C) 2003, 2004, 2005, 2007, 2008, 2009
- Free Software Foundation, Inc.
+ Copyright (C) 2003-2015 Free Software Foundation, Inc.
This file is part of GDB.
#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);
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