From: Jiri Slaby <jslaby@suse.cz>
Date: Fri, 1 Dec 2017 08:28:36 +0100
Subject: x86/stacktrace: remove STACKTRACE_DUMP_ONCE from
 __save_stack_trace_reliable
Patch-mainline: submitted on 2017/12/5
References: bnc#1058115

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@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
---
 arch/x86/kernel/stacktrace.c |    8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

--- a/arch/x86/kernel/stacktrace.c
+++ b/arch/x86/kernel/stacktrace.c
@@ -125,20 +125,16 @@ __save_stack_trace_reliable(struct stack
 		 * 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)))