[Crash-utility] [PATCH 6/6] x86_64: Trace RBP chain on kernel stack only if unwind() fails
- unwind() logic attempts to collect all the callee-saved registers including
RBP. So, RBP chain tracing is necessary only if this unwind() logic doesn't
succeed.
- Also, verify whether a given task is not active. This is because for active
tasks, RBP saved on the corresponding kernel stacks could be modified.
Signed-off-by: HATAYAMA Daisuke <d.hatayama(a)jp.fujitsu.com>
---
src/libgcore/gcore_x86.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/src/libgcore/gcore_x86.c b/src/libgcore/gcore_x86.c
index 8c129d3..871a9db 100644
--- a/src/libgcore/gcore_x86.c
+++ b/src/libgcore/gcore_x86.c
@@ -1258,7 +1258,7 @@ static inline void restore_rest(ulong task, struct pt_regs *regs,
* could trace the value of bp until its value became a
* user-space address. See comments of restore_frame_pointer.
*/
- if (machdep->flags & FRAMEPOINTER) {
+ else if ((machdep->flags & FRAMEPOINTER) && !is_task_active(task)) {
regs->rbp = restore_frame_pointer(task);
}
}
--
1.7.4