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=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 47E16C433DF for ; Fri, 21 Aug 2020 11:47:24 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 01319204EC for ; Fri, 21 Aug 2020 11:47:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=hostfission.com header.i=@hostfission.com header.b="ROhp0wa9" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 01319204EC Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=hostfission.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:51768 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1k95Vz-0002Vu-3N for qemu-devel@archiver.kernel.org; Fri, 21 Aug 2020 07:47:23 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:44596) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k95E4-0001jB-3t for qemu-devel@nongnu.org; Fri, 21 Aug 2020 07:28:52 -0400 Received: from mail1.hostfission.com ([139.99.139.48]:44010) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1k95E2-00011g-4s for qemu-devel@nongnu.org; Fri, 21 Aug 2020 07:28:51 -0400 Received: from www1.hostfission.com (www1.hostfission.com [139.99.139.52]) by mail1.hostfission.com (Postfix) with ESMTP id D7883405E8; Fri, 21 Aug 2020 21:28:44 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hostfission.com; s=mail; t=1598009324; bh=2pTHj+PCws8Rq30Y9j4PZL3rmeVtYANvCBCqBgWcCSM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=ROhp0wa9RRaKGx29IDXOa5gDd/4dbVk4+zOia4Kmk+RxOONK5H6WGRhFpoBY2ut/q y350JE35zmZrgjBWrdyAlu2p3xThQQ1es7bJtVdTkEjNAiFR/rpv0JWmdin8BKnoxb n8UFAxrIQTyqmXJIRLoFGj4paTXgty7BU08WAWjg= Received: from mail.hostfission.com (www1.hostfission.com [127.0.0.1]) by www1.hostfission.com (Postfix) with ESMTP id C5E5087E5A; Fri, 21 Aug 2020 21:28:44 +1000 (AEST) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Fri, 21 Aug 2020 21:28:44 +1000 From: Geoffrey McRae To: Paolo Bonzini Cc: Christian Schoenebeck , qemu-devel@nongnu.org, Gerd Hoffmann Subject: Re: [PATCH v5 1/1] audio/jack: fix use after free segfault In-Reply-To: References: <20200819062940.52774-1-geoff@hostfission.com> <5029913.bOW1W81TKx@silver> <20200820053728.kv7pngxqzp32uky3@sirius.home.kraxel.org> <3140676.b1PlGooJ8z@silver> Message-ID: X-Sender: geoff@hostfission.com User-Agent: Roundcube Webmail/1.3.8 Received-SPF: pass client-ip=139.99.139.48; envelope-from=geoff@hostfission.com; helo=mail1.hostfission.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/08/21 07:28:45 X-ACL-Warn: Detected OS = Linux 3.11 and newer X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" > My suggestion is to work towards protecting the audio code with its own > mutex(es) and ignore the existence of the BQL for subsystems that can > do > so (audio is a prime candidate). Also please add comments to > audio_int.h about which functions are called from other threads than > the > QEMU main thread. Ok, so to get back on topic, what exactly is the best way forward to fix this issue in this patchset? Should I be managing a local mutex instead? > > Thanks, > > Paolo > > [1] https://lamport.azurewebsites.net/pubs/teaching-concurrency.pdf