From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754293AbbIJOyD (ORCPT ); Thu, 10 Sep 2015 10:54:03 -0400 Received: from mail-pa0-f54.google.com ([209.85.220.54]:35000 "EHLO mail-pa0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753968AbbIJOx4 (ORCPT ); Thu, 10 Sep 2015 10:53:56 -0400 Date: Thu, 10 Sep 2015 10:53:52 -0400 From: Tejun Heo To: Lai Jiangshan Cc: sedat.dilek@gmail.com, LKML Subject: Re: [Linux v4.2] workqueue: llvmlinux: acpid: BUG: sleeping function called from invalid context at kernel/workqueue.c:2680 Message-ID: <20150910145352.GE8114@mtj.duckdns.org> References: <20150910145227.GD8114@mtj.duckdns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150910145227.GD8114@mtj.duckdns.org> 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 On Thu, Sep 10, 2015 at 10:52:27AM -0400, Tejun Heo wrote: > Hey, > > On Thu, Sep 10, 2015 at 09:04:27AM +0800, Lai Jiangshan wrote: > > I think we need to add might_sleep() on the top of __cancel_work_timer(). > > The might_sleep() on the start_flush_work() doesn't cover all the > > paths of __cancel_work_timer(). > > And it can help to narrow the area of this bug. > > Sure, can you submit a patch? That said, this one is likely not a bug in the kernel code but more likely llvm either miscompiling or deviating from gcc behavior on some corner cases. Thanks. -- tejun