panic: print out stacktrace if DEBUG_BUGVERBOSE

if CONFIG_DEBUG_BUGVERBOSE is set then the user most definitely wanted
to see as much information about kernel crashes as possible - so give
them at least a stack dump.

this is particularly useful for stackprotector related panics, where
the stacktrace can give us the exact location of the (attempted)
attack.

Pointed out by pageexec@freemail.hu in the stackprotector breakage
threads.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 3 insertions, 0 deletions

diff --git a/kernel/panic.c b/kernel/panic.c
index f236001cc4db..17aad578a2f2 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -80,6 +80,9 @@ NORET_TYPE void panic(const char * fmt, ...)
         vsnprintf(buf, sizeof(buf), fmt, args);
         va_end(args);
         printk(KERN_EMERG "Kernel panic - not syncing: %s\n",buf);
+#ifdef CONFIG_DEBUG_BUGVERBOSE
+        dump_stack();
+#endif
         bust_spinlocks(0);
 
         /*