Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754141Ab3GXOa7 (ORCPT ); Wed, 24 Jul 2013 10:30:59 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:45697 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751153Ab3GXOGd (ORCPT ); Wed, 24 Jul 2013 10:06:33 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Peter Zijlstra" , "Bu, Yitian" , "Thomas Gleixner" Date: Wed, 24 Jul 2013 15:02:45 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [02/85] printk: Fix rq->lock vs logbuf_lock unlock lock inversion In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.101 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1473 Lines: 45 3.2.49-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: "Bu, Yitian" commit dbda92d16f8655044e082930e4e9d244b87fde77 upstream. commit 07354eb1a74d1 ("locking printk: Annotate logbuf_lock as raw") reintroduced a lock inversion problem which was fixed in commit 0b5e1c5255 ("printk: Release console_sem after logbuf_lock"). This happened probably when fixing up patch rejects. Restore the ordering and unlock logbuf_lock before releasing console_sem. Signed-off-by: ybu Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/E807E903FE6CBE4D95E420FBFCC273B827413C@nasanexd01h.na.qualcomm.com Signed-off-by: Thomas Gleixner [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings --- kernel/printk.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/kernel/printk.c +++ b/kernel/printk.c @@ -813,9 +813,9 @@ static int console_trylock_for_printk(un } } printk_cpu = UINT_MAX; + raw_spin_unlock(&logbuf_lock); if (wake) up(&console_sem); - raw_spin_unlock(&logbuf_lock); return retval; } static const char recursion_bug_msg [] = -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/