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authorAaron Tomlin <atomlin@redhat.com>2014-03-24 14:03:57 +0000
committerSteven Rostedt <rostedt@goodmis.org>2014-03-24 10:39:11 -0400
commit3862807880acc0adaef6749738d210c9f45c3049 (patch)
tree1545044eb873c915f015288fb4b45e5a3bd50a55 /kernel/trace
parent0dea6d52638b2693b18cd2ed8938b236e0789ddb (diff)
downloadblackbird-op-linux-3862807880acc0adaef6749738d210c9f45c3049.tar.gz
blackbird-op-linux-3862807880acc0adaef6749738d210c9f45c3049.zip
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 <atomlin@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/trace_stack.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index e6be585cf06a..21b320e5d163 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -13,6 +13,7 @@
#include <linux/sysctl.h>
#include <linux/init.h>
#include <linux/fs.h>
+#include <linux/magic.h>
#include <asm/setup.h>
@@ -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);
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