From: Vitaly Kuznetsov <[email protected]>

3.12-stable review patch.  If anyone has any objections, please let me know.

===============

commit 7625b3a0007decf2b135cb47ca67abc78a7b1bc1 upstream.

Commit 08d78658f393 ("panic: release stale console lock to always get the
logbuf printed out") introduced an unwanted bad unlock balance report when
panic() is called directly and not from OOPS (e.g.  from out_of_memory()).
The difference is that in case of OOPS we disable locks debug in
oops_enter() and on direct panic call nobody does that.

Fixes: 08d78658f393 ("panic: release stale console lock to always get the 
logbuf printed out")
Reported-by: kernel test robot <[email protected]>
Signed-off-by: Vitaly Kuznetsov <[email protected]>
Cc: HATAYAMA Daisuke <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Jiri Kosina <[email protected]>
Cc: Baoquan He <[email protected]>
Cc: Prarit Bhargava <[email protected]>
Cc: Xie XiuQi <[email protected]>
Cc: Seth Jennings <[email protected]>
Cc: "K. Y. Srinivasan" <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Petr Mladek <[email protected]>
Cc: Yasuaki Ishimatsu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Jiri Slaby <[email protected]>
---
 kernel/panic.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/kernel/panic.c b/kernel/panic.c
index de5924c75b1b..639255d5e5e1 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -138,8 +138,11 @@ void panic(const char *fmt, ...)
         * 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.
+        * 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_flush_on_panic();
 
        if (!panic_blink)
-- 
2.11.0

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