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[3/3] xtensa: fix _Unwind_GetCFA

Message ID 1439848790-3488-4-git-send-email-jcmvbkbc@gmail.com
State New
Headers show

Commit Message

Max Filippov Aug. 17, 2015, 9:59 p.m. UTC 
Returning context->cfa in _Unwind_GetCFA makes CFA point one stack frame
higher than what was actually used by code at context->ra. This results
in invalid CFA value in signal frames and premature unwinding completion
in forced unwinding used by uClibc NPTL thread cancellation.
Returning context->sp from _Unwind_GetCFA makes all CFA values valid and
matching code that used them.

2015-08-18  Max Filippov  <jcmvbkbc@gmail.com>
libgcc/
	* config/xtensa/unwind-dw2-xtensa.c (_Unwind_GetCFA): Return
	context->sp instead of context->cfa.
---
 libgcc/config/xtensa/unwind-dw2-xtensa.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

augustine.sterling@gmail.com Aug. 18, 2015, 12:51 a.m. UTC | #1 
On Mon, Aug 17, 2015 at 2:59 PM, Max Filippov <jcmvbkbc@gmail.com> wrote:
> 2015-08-18  Max Filippov  <jcmvbkbc@gmail.com>
> libgcc/
>         * config/xtensa/unwind-dw2-xtensa.c (_Unwind_GetCFA): Return
>         context->sp instead of context->cfa.

Approved.
diff mbox

Patch

diff --git a/libgcc/config/xtensa/unwind-dw2-xtensa.c b/libgcc/config/xtensa/unwind-dw2-xtensa.c
index 82b0e63..8e579c7 100644
--- a/libgcc/config/xtensa/unwind-dw2-xtensa.c
+++ b/libgcc/config/xtensa/unwind-dw2-xtensa.c
@@ -130,7 +130,7 @@  _Unwind_GetGR (struct _Unwind_Context *context, int index)
 _Unwind_Word
 _Unwind_GetCFA (struct _Unwind_Context *context)
 {
-  return (_Unwind_Ptr) context->cfa;
+  return (_Unwind_Ptr) context->sp;
 }
 
 /* Overwrite the saved value for register INDEX in CONTEXT with VAL.  */