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arm: Fix is_signal_frame bug for Thumb/Thumb2 mode

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If Thumb is used, the least bit of the retrived IP value is set,
which makes the retrived opcode based on the IP invalid.

This patch fixes such behavior and adds a missed condition
found with glibc built for recent ARMv7l with Thumb2.

Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

CC: Yvan Roux
CC: Arun Sharma
CC: David Mosberger
This commit is contained in:
MyungJoo Ham 2016-05-19 02:52:09 +00:00 committed by Dave Watson
parent c4accd6ea2
commit ed90c8387b
1 changed files with 12 additions and 3 deletions
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15
src/arm/Gis_signal_frame.c
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@ -44,6 +44,13 @@ WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/* Thumb sigreturn (two insns, syscall number is loaded into r7) */
#define THUMB_SIGRETURN (0xdf00UL << 16 | 0x2700 | ARM_NR_sigreturn)
#define THUMB_RT_SIGRETURN (0xdf00UL << 16 | 0x2700 | ARM_NR_rt_sigreturn)
/* Thumb2 sigreturn (mov.w r7, $SYS_ify(rt_sigreturn/sigreturn)) */
#define THUMB2_SIGRETURN (((0x0700 | ARM_NR_sigreturn) << 16) | \
0xf04f)
#define THUMB2_RT_SIGRETURN (((0x0700 | ARM_NR_rt_sigreturn) << 16) | \
0xf04f)
/* TODO: with different toolchains, there are a lot more possibilities */
#endif /* __linux__ */
/* Returns 1 in case of a non-RT signal frame and 2 in case of a RT signal
@ -63,17 +70,19 @@ unw_is_signal_frame (unw_cursor_t *cursor)
a = unw_get_accessors (as);
arg = c->dwarf.as_arg;
ip = c->dwarf.ip;
/* The least bit denotes thumb/arm mode. Do not read there. */
ip = c->dwarf.ip & ~0x1;
if ((ret = (*a->access_mem) (as, ip, &w0, 0, arg)) < 0)
return ret;
/* Return 1 if the IP points to a non-RT sigreturn sequence. */
if (w0 == MOV_R7_SIGRETURN || w0 == ARM_SIGRETURN || w0 == THUMB_SIGRETURN)
if (w0 == MOV_R7_SIGRETURN || w0 == ARM_SIGRETURN || w0 == THUMB_SIGRETURN
|| w0 == THUMB2_SIGRETURN)
return 1;
/* Return 2 if the IP points to a RT sigreturn sequence. */
else if (w0 == MOV_R7_RT_SIGRETURN || w0 == ARM_RT_SIGRETURN
|| w0 == THUMB_RT_SIGRETURN)
|| w0 == THUMB_RT_SIGRETURN || w0 == THUMB2_RT_SIGRETURN)
return 2;
return 0;