From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20130911042856.926765523@goodmis.org> Date: Wed, 11 Sep 2013 00:27:35 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: ybu , Peter Zijlstra , Thomas Gleixner Subject: [028/251] printk: Fix rq->lock vs logbuf_lock unlock lock inversion References: <20130911042707.738353451@goodmis.org> Content-Disposition: inline; filename=0028-printk-Fix-rq-lock-vs-logbuf_lock-unlock-lock-invers.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.6.11.9-rc1 stable review patch. If anyone has any objections, please let me know. ------------------ From: "Bu, Yitian" [ Upstream commit dbda92d16f8655044e082930e4e9d244b87fde77 ] 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 Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/E807E903FE6CBE4D95E420FBFCC273B827413C@nasanexd01h.na.qualcomm.com Signed-off-by: Thomas Gleixner Signed-off-by: Steven Rostedt --- kernel/printk.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/printk.c b/kernel/printk.c index 2d3fc0e..74a3afb 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -1364,9 +1364,9 @@ static int console_trylock_for_printk(unsigned int cpu) } } logbuf_cpu = UINT_MAX; + raw_spin_unlock(&logbuf_lock); if (wake) up(&console_sem); - raw_spin_unlock(&logbuf_lock); return retval; } -- 1.7.10.4