From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 16D3FC3A589 for ; Tue, 20 Aug 2019 13:13:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D15E820673 for ; Tue, 20 Aug 2019 13:13:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=mork.no header.i=@mork.no header.b="kWW9y5Fh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729261AbfHTNNg (ORCPT ); Tue, 20 Aug 2019 09:13:36 -0400 Received: from canardo.mork.no ([148.122.252.1]:37219 "EHLO canardo.mork.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728595AbfHTNNg (ORCPT ); Tue, 20 Aug 2019 09:13:36 -0400 Received: from miraculix.mork.no ([IPv6:2a02:2121:301:f490:2886:93ff:fe90:318c]) (authenticated bits=0) by canardo.mork.no (8.15.2/8.15.2) with ESMTPSA id x7KDDDJ3013260 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Tue, 20 Aug 2019 15:13:14 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mork.no; s=b; t=1566306794; bh=0T5LzHKB96aCeBiY/QH/lE5XRY7wPvG0Bd1Nxw1LE+Q=; h=From:To:Cc:Subject:References:Date:Message-ID:From; b=kWW9y5Fh3HZu49+oI+AFlSZfaeKfzw4Qf/iMwWJm965FW6/4rgWQPbuuO2GuHaZ2p IX4QtVmnYbmFzFqIyZVrgfGRz+t77lvsoyabyS2wg1BIf7jlcwmWrN7qR89U4X00R6 pD78/KC9SnnmUnzoHxCBJbGPHCp2/LWl9IorlqwY= Received: from bjorn by miraculix.mork.no with local (Exim 4.92) (envelope-from ) id 1i03wn-0000Wu-JX; Tue, 20 Aug 2019 15:13:13 +0200 From: =?utf-8?Q?Bj=C3=B8rn_Mork?= To: Oliver Neukum Cc: syzbot , gustavo@embeddedor.com, andreyknvl@google.com, syzkaller-bugs@googlegroups.com, gregkh@linuxfoundation.org, linux-usb@vger.kernel.org Subject: Re: WARNING in wdm_write/usb_submit_urb Organization: m References: <000000000000719222059081d6f2@google.com> <1566304128.11678.14.camel@suse.com> Date: Tue, 20 Aug 2019 15:13:13 +0200 In-Reply-To: <1566304128.11678.14.camel@suse.com> (Oliver Neukum's message of "Tue, 20 Aug 2019 14:28:48 +0200") Message-ID: <87imqs56ae.fsf@miraculix.mork.no> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Virus-Scanned: clamav-milter 0.101.2 at canardo X-Virus-Status: Clean Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Oliver Neukum writes: > + wait_event(desc->wait, > + /* > + * needs both flags. We cannot do with one > + * because resetting it would cause a race > + * with write() yet we need to signal > + * a disconnect > + */ > + !test_bit(WDM_IN_USE, &desc->flags) && > + test_bit(WDM_DISCONNECTING, &desc->flags)); I'm confused now... Won't this condition always be false? Should be wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags) || test_bit(WDM_DISCONNECTING, &desc->flags)); instead, or? Bj=C3=B8rn