From 3862807880acc0adaef6749738d210c9f45c3049 Mon Sep 17 00:00:00 2001 From: Aaron Tomlin Date: Mon, 24 Mar 2014 14:03:57 +0000 Subject: tracing: Add BUG_ON when stack end location is over written 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(+) (limited to 'kernel/trace') 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); -- cgit v1.1