Sync to Linus v4.4-rc2 for LSM developers.

1 files changed, 13 insertions, 0 deletions

diff --git a/kernel/panic.c b/kernel/panic.c
index 04e91ff7560b..4b150bc0c6c1 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -23,6 +23,7 @@
 #include <linux/sysrq.h>
 #include <linux/init.h>
 #include <linux/nmi.h>
+#include <linux/console.h>
 
 #define PANIC_TIMER_STEP 100
 #define PANIC_BLINK_SPD 18
@@ -147,6 +148,18 @@ void panic(const char *fmt, ...)
 
 	bust_spinlocks(0);
 
+	/*
+	 * We may have ended up stopping the CPU holding the lock (in
+	 * smp_send_stop()) while still having some valuable data in the console
+	 * buffer.  Try to acquire the lock then release it regardless of the
+	 * result.  The release will also print the buffers out.  Locks debug
+	 * should be disabled to avoid reporting bad unlock balance when
+	 * panic() is not being callled from OOPS.
+	 */
+	debug_locks_off();
+	console_trylock();
+	console_unlock();
+
 	if (!panic_blink)
 		panic_blink = no_blink;