Remove support for pre-5.0 FreeBSD/i386 signal trampolines.

The last relevant release (FreeBSD 4.11) was released in January of
2005.
This commit is contained in:
John Baldwin 2022-01-28 11:14:37 -08:00
parent 187365caaa
commit bf84b776bd

View file

@ -37,12 +37,10 @@
/* 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. */
/* FreeBSD/i386 binaries running under an amd64 kernel use a different
trampoline This trampoline differs from the i386 kernel trampoline
in that it omits a middle section that conditionally restores
%gs. */
static const gdb_byte i386fbsd_sigtramp_start[] =
{
@ -65,62 +63,6 @@ static const gdb_byte i386fbsd_sigtramp_end[] =
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);
@ -132,31 +74,13 @@ 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
!= 0)
return 0;
/* Since the end is shorter than the middle, check for a matching end
@ -165,14 +89,15 @@ i386fbsd_sigtramp_p (struct frame_info *this_frame)
if (!safe_frame_unwind_memory (this_frame, pc,
{buf, sizeof i386fbsd_sigtramp_end}))
return 0;
if (memcmp (buf, end, sizeof i386fbsd_sigtramp_end) == 0)
if (memcmp (buf, i386fbsd_sigtramp_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)
if (memcmp (buf, i386fbsd_sigtramp_middle, sizeof i386fbsd_sigtramp_middle)
!= 0)
return 0;
/* The middle matched, check for a matching end. */
@ -180,7 +105,7 @@ i386fbsd_sigtramp_p (struct frame_info *this_frame)
if (!safe_frame_unwind_memory (this_frame, pc,
{buf, sizeof i386fbsd_sigtramp_end}))
return 0;
if (memcmp (buf, end, sizeof i386fbsd_sigtramp_end) != 0)
if (memcmp (buf, i386fbsd_sigtramp_end, sizeof i386fbsd_sigtramp_end) != 0)
return 0;
return 1;