From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932829AbcBCWh2 (ORCPT ); Wed, 3 Feb 2016 17:37:28 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:47061 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934081AbcBCWhO (ORCPT ); Wed, 3 Feb 2016 17:37:14 -0500 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Vitaly Kuznetsov , HATAYAMA Daisuke , Masami Hiramatsu , Jiri Kosina , Baoquan He , Prarit Bhargava , Xie XiuQi , Seth Jennings , "K. Y. Srinivasan" , Jan Kara , Petr Mladek , Yasuaki Ishimatsu , Andrew Morton , Linus Torvalds , Luis Henriques Subject: [PATCH 3.16.y-ckt 117/180] kernel/panic.c: turn off locks debug before releasing console lock Date: Wed, 3 Feb 2016 22:32:03 +0000 Message-Id: <1454538786-12215-118-git-send-email-luis.henriques@canonical.com> In-Reply-To: <1454538786-12215-1-git-send-email-luis.henriques@canonical.com> References: <1454538786-12215-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.7-ckt24 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Vitaly Kuznetsov 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 Signed-off-by: Vitaly Kuznetsov Cc: HATAYAMA Daisuke Cc: Masami Hiramatsu Cc: Jiri Kosina Cc: Baoquan He Cc: Prarit Bhargava Cc: Xie XiuQi Cc: Seth Jennings Cc: "K. Y. Srinivasan" Cc: Jan Kara Cc: Petr Mladek Cc: Yasuaki Ishimatsu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Luis Henriques --- kernel/panic.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/kernel/panic.c b/kernel/panic.c index df1d13ee481c..b3c877653d9c 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -150,8 +150,11 @@ 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();