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 <[email protected]> CC: Yvan Roux CC: Arun Sharma CC: David Mosberger --- src/arm/Gis_signal_frame.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/src/arm/Gis_signal_frame.c b/src/arm/Gis_signal_frame.c index e8efe7f..bfae4c6 100644 --- a/src/arm/Gis_signal_frame.c +++ b/src/arm/Gis_signal_frame.c @@ -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; -- 1.9.1 _______________________________________________ Libunwind-devel mailing list [email protected] https://lists.nongnu.org/mailman/listinfo/libunwind-devel
