[PATCH v2 3/6] x86/stacktrace: remove STACKTRACE_DUMP_ONCE from __save_stack_trace_reliable

From: Jiri Slaby
Date: Mon May 14 2018 - 10:08:44 EST


The stack unwinding can sometimes fail yet. Especially with the
generated debug info. So do not yell at users -- live patching (the only
user of this interface) will inform the user about the failure
gracefully.

Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: x86@xxxxxxxxxx
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
arch/x86/kernel/stacktrace.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c
index 3a4602c2324f..e0169b128523 100644
--- a/arch/x86/kernel/stacktrace.c
+++ b/arch/x86/kernel/stacktrace.c
@@ -125,20 +125,16 @@ __save_stack_trace_reliable(struct stack_trace *trace,
* generated code which __kernel_text_address() doesn't know
* about.
*/
- if (!addr) {
- STACKTRACE_DUMP_ONCE(task);
+ if (!addr)
return -EINVAL;
- }

if (save_stack_address(trace, addr, false))
return -EINVAL;
}

/* Check for stack corruption */
- if (unwind_error(&state)) {
- STACKTRACE_DUMP_ONCE(task);
+ if (unwind_error(&state))
return -EINVAL;
- }

/* Success path for non-user tasks, i.e. kthreads and idle tasks */
if (!(task->flags & (PF_KTHREAD | PF_IDLE)))
--
2.16.3