kernel/panic.c: turn off locks debug before releasing console lock

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 <ying.huang@linux.intel.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Baoquan He <bhe@redhat.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Xie XiuQi <xiexiuqi@huawei.com>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Petr Mladek <pmladek@suse.cz>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[jy0922.shim: apply from mainline for console lockup debugging of drm]
Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Change-Id: Ia6a7ce2ee74a846363501db8fc5cdbec96216b33

diff --git a/kernel/panic.c b/kernel/panic.c
index dae109ea89ebaacace8ec2fae827113e066b88f1..466c16f8190d31c4969c0af9e5a4012a70040fb0 100644 (file)
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -151,8 +151,11 @@ 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_trylock();
        console_unlock();