From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932335Ab3BSD4x (ORCPT ); Mon, 18 Feb 2013 22:56:53 -0500 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:28627 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932166Ab3BSD4r (ORCPT ); Mon, 18 Feb 2013 22:56:47 -0500 X-Authority-Analysis: v=2.0 cv=adbjbGUt c=1 sm=0 a=rXTBtCOcEpjy1lPqhTCpEQ==:17 a=mNMOxpOpBa8A:10 a=Ciwy3NGCPMMA:10 a=SM_E_W5WZlwA:10 a=5SG0PmZfjMsA:10 a=bbbx4UPp9XUA:10 a=meVymXHHAAAA:8 a=gXKFKoqqhuYA:10 a=EUspDBNiAAAA:8 a=VwQbUJbxAAAA:8 a=3bbGOjw-qwAXQl4_qLUA:9 a=Zh68SRI7RUMA:10 a=jeBq3FmKZ4MA:10 a=rXTBtCOcEpjy1lPqhTCpEQ==:117 X-Cloudmark-Score: 0 X-Authenticated-User: X-Originating-IP: 74.67.115.198 Message-Id: <20130219035645.895239359@goodmis.org> User-Agent: quilt/0.60-1 Date: Mon, 18 Feb 2013 22:56:26 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-rt-users Cc: Thomas Gleixner , Carsten Emde , John Kacur , ybu , Peter Zijlstra , , Subject: [PATCH RT 3/7] printk: Fix rq->lock vs logbuf_lock unlock lock inversion References: <20130219035623.277664914@goodmis.org> Content-Disposition: inline; filename=0003-printk-Fix-rq-lock-vs-logbuf_lock-unlock-lock-invers.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Bu, Yitian" 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 Cc: stable-rt@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 972cc56..37b9b99 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -867,9 +867,9 @@ static int console_trylock_for_printk(unsigned int cpu, unsigned long flags) } } 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 [] = -- 1.7.10.4