From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751664AbaCZEIM (ORCPT ); Wed, 26 Mar 2014 00:08:12 -0400 Received: from cdptpa-outbound-snat.email.rr.com ([107.14.166.232]:12178 "EHLO cdptpa-oedge-vip.email.rr.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751487AbaCZEIG (ORCPT ); Wed, 26 Mar 2014 00:08:06 -0400 Message-Id: <20140326040803.923522970@goodmis.org> User-Agent: quilt/0.61-1 Date: Wed, 26 Mar 2014 00:07:33 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Frederic Weisbecker , Andrew Morton , Aaron Tomlin Subject: [for-next][PATCH 2/2] tracing: Add BUG_ON when stack end location is over written References: <20140326040731.610462407@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline; filename=0002-tracing-Add-BUG_ON-when-stack-end-location-is-over-w.patch X-RR-Connecting-IP: 107.14.168.118:25 X-Cloudmark-Score: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Aaron Tomlin It is difficult to detect a stack overrun when it actually occurs. We have observed that this type of corruption is often silent and can go unnoticed. Once the corrupted region is examined, the outcome is undefined and often results in sporadic system crashes. When the stack tracing feature is enabled, let's check for this condition and take appropriate action. Note: init_task doesn't get its stack end location set to STACK_END_MAGIC. Link: http://lkml.kernel.org/r/1395669837-30209-1-git-send-email-atomlin@redhat.com Signed-off-by: Aaron Tomlin Signed-off-by: Steven Rostedt --- kernel/trace/trace_stack.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index e6be585..21b320e 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -13,6 +13,7 @@ #include #include #include +#include #include @@ -144,6 +145,8 @@ check_stack(unsigned long ip, unsigned long *stack) i++; } + BUG_ON(current != &init_task && + *(end_of_stack(current)) != STACK_END_MAGIC); out: arch_spin_unlock(&max_stack_lock); local_irq_restore(flags); -- 1.8.5.3