Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753927AbbEUGD4 (ORCPT ); Thu, 21 May 2015 02:03:56 -0400 Received: from mail-wg0-f50.google.com ([74.125.82.50]:34968 "EHLO mail-wg0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751140AbbEUGDx (ORCPT ); Thu, 21 May 2015 02:03:53 -0400 Date: Thu, 21 May 2015 08:03:48 +0200 From: Ingo Molnar To: Maninder Singh Cc: akpm@linux-foundation.org, oleg@redhat.com, mhocko@suse.cz, peterz@infradead.org, riel@redhat.com, ionut.m.alexa@gmail.com, peter@hurleysoftware.com, linux-kernel@vger.kernel.org, "v.narang@samsung.com" , AKHILESH KUMAR , Peter Zijlstra Subject: Re: [EDT][PATCH] kernel/exit.c : Fix missing read_unlock Message-ID: <20150521060348.GA5615@gmail.com> References: <670017389.505251432184399737.JavaMail.weblogic@ep2mlwas07b> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <670017389.505251432184399737.JavaMail.weblogic@ep2mlwas07b> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1873 Lines: 71 * Maninder Singh wrote: > EP-F6AA0618C49C4AEDA73BFF1B39950BAB > Hi, > > From: Maninder Singh > > Subject: [PATCH 1/1] kernel/exit.c : Fix missing task_unlock > > This patch adds missing read_unlock if do_wait_thread or ptrace_do_wait > returns non zero. > > Signed-off-by: Maninder Singh > Signed-off-by: Vaneet Narang > Reviewd-by: Akhilesh Kumar > --- > kernel/exit.c | 8 ++++++-- > 1 files changed, 6 insertions(+), 2 deletions(-) > > diff --git a/kernel/exit.c b/kernel/exit.c > index 22fcc05..31a061f 100644 > --- a/kernel/exit.c > +++ b/kernel/exit.c > @@ -1486,12 +1486,16 @@ repeat: > tsk = current; > do { > retval = do_wait_thread(wo, tsk); > - if (retval) > + if (retval) { > + read_unlock(&tasklist_lock); > goto end; > + } > > retval = ptrace_do_wait(wo, tsk); > - if (retval) > + if (retval) { > + read_unlock(&tasklist_lock); > goto end; > + } > > if (wo->wo_flags & __WNOTHREAD) > break; That's surprising and the changelog is lacking. So the last time that code was touched upstream was 7 years ago: commit 64a16caf5e3417ee32f670debcb5857b02a9e08e Author: Oleg Nesterov Date: Wed Jun 17 16:27:40 2009 -0700 do_wait: simplify retval/tsk_result/notask_error mess please explain whether what you fix is: 1) an ancient bug that somehow nobody ever triggered (plus analysis of why it wasn't triggered) 2) a new bug introduced by commit XYZ (plus analysis) 3) something else Thanks, Ingo -- 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/