From patchwork Fri Apr 8 22:17:10 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tong Zhang X-Patchwork-Id: 12807250 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id D43D1C433F5 for ; Fri, 8 Apr 2022 22:19:18 +0000 (UTC) Received: from localhost ([::1]:49808 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ncwwn-0002O3-F4 for qemu-devel@archiver.kernel.org; Fri, 08 Apr 2022 18:19:17 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:57136) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ncwux-0001cU-6r for qemu-devel@nongnu.org; Fri, 08 Apr 2022 18:17:23 -0400 Received: from mailout2.w2.samsung.com ([211.189.100.12]:13787) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ncwuu-00043j-TV for qemu-devel@nongnu.org; Fri, 08 Apr 2022 18:17:22 -0400 Received: from uscas1p2.samsung.com (unknown [182.198.245.207]) by mailout2.w2.samsung.com (KnoxPortal) with ESMTP id 20220408221712usoutp023384d1b2b9e043e01995fe95afbd837a~kC7RZ4NZZ0503205032usoutp02G; Fri, 8 Apr 2022 22:17:12 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 mailout2.w2.samsung.com 20220408221712usoutp023384d1b2b9e043e01995fe95afbd837a~kC7RZ4NZZ0503205032usoutp02G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=samsung.com; s=mail20170921; t=1649456232; bh=1ZjvoENIycjky5C3cXuao6J9XyheLQrjNGLqV80MRCw=; h=From:To:CC:Subject:Date:References:From; b=lg0dD54EAINgJD6dVIa3KU9UNqej0M0QJrRkf4w5vIikzZ1i54SRr8T10E6h8QVQW VNYVYz2Ax3lOhA0+iKu9ofT6IXYCjk7dhvzMZYWuYxYnX86NZcdlgAwY3J8OOvVFEL iymKMgxfnh75Pz/zHFXKSese0gRJZhuNe6YYe3qQ= Received: from ussmges2new.samsung.com (u111.gpu85.samsung.co.kr [203.254.195.111]) by uscas1p2.samsung.com (KnoxPortal) with ESMTP id 20220408221712uscas1p2eabd510fb75e173a34976d930516e80e~kC7Q_IT-n1844518445uscas1p2v; Fri, 8 Apr 2022 22:17:12 +0000 (GMT) Received: from uscas1p2.samsung.com ( [182.198.245.207]) by ussmges2new.samsung.com (USCPEMTA) with SMTP id 7C.96.09642.864B0526; Fri, 8 Apr 2022 18:17:12 -0400 (EDT) Received: from ussmgxs2new.samsung.com (u91.gpu85.samsung.co.kr [203.254.195.91]) by uscas1p2.samsung.com (KnoxPortal) with ESMTP id 20220408221711uscas1p2d64b2adae902cc51d328882980fbc50b~kC7Qq3g2w2064620646uscas1p2X; Fri, 8 Apr 2022 22:17:11 +0000 (GMT) X-AuditID: cbfec36f-bfdff700000025aa-87-6250b46851c6 Received: from SSI-EX2.ssi.samsung.com ( [105.128.2.145]) by ussmgxs2new.samsung.com (USCPEXMTA) with SMTP id B2.36.09672.764B0526; Fri, 8 Apr 2022 18:17:11 -0400 (EDT) Received: from SSI-EX2.ssi.samsung.com (105.128.2.227) by SSI-EX2.ssi.samsung.com (105.128.2.227) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.1.2242.4; Fri, 8 Apr 2022 15:17:11 -0700 Received: from SSI-EX2.ssi.samsung.com ([fe80::2149:7df2:31b5:d9a0]) by SSI-EX2.ssi.samsung.com ([fe80::719f:92d1:f17f:5400%4]) with mapi id 15.01.2242.008; Fri, 8 Apr 2022 15:17:11 -0700 From: Tong Zhang To: Paolo Bonzini , Peter Xu , "David Hildenbrand" , =?iso-8859-1?q?Philippe_Mathieu-Dau?= =?iso-8859-1?q?d=E9?= , "qemu-devel@nongnu.org" Subject: [PATCH] hw/dma: fix crash caused by race condition Thread-Topic: [PATCH] hw/dma: fix crash caused by race condition Thread-Index: AQHYS5ZkVMtIe81jHEmRve4sseIikw== Date: Fri, 8 Apr 2022 22:17:10 +0000 Message-ID: <20220408221701.9081-1-t.zhang2@samsung.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [105.128.2.176] MIME-Version: 1.0 X-CFilter-Loop: Reflected X-Brightmail-Tracker: H4sIAAAAAAAAA02SWUwTURSGvTPDdEDbDBXtEYjBaqJQW5conURjiPJQfVCMMSTEBAqM7AVb Ky4ExOCGuCX2wbpgkSLSIoQ2BAQLLbiAilsAadxqcEEMSyJbtVXoYMLb/+d855z/nlwKF+r8 gqk01UFWrVJmiskAov7R2AtpqjUmcW3Nl/nMWI0bZ57U2XGmpd7rx1hbxnnM4/MNBNPx4wUZ RSpavxt4ikb9e56iv8eCKYZt3WQMERewOZnNTDvEqtdsSQhIvfErPcfif9hQLjiO+njFyJ8C egO8PNNFFKMASkjfRfDVU4tx5iQGRabn6D9lHXjm00K6GkF1ex4HjSBw9V7kcaYFwbXmFh9F 0ivBfbaMnCkE0S4EgxcqyZkCThfAlSkrNqMX0ptA12TwNQTRUXB/eBDjtAysRo/fjCboFXCy 4YdP82kGGnQ1Ph7Ri2Gi04xxM0Xg7C/FuKiBUHatGef0YvDed5GcXgYfJwZ4HC+Dt7ors3kk UGEYxLn5gdBxtZ/g+CVgr3zrOwzQNygwtjdPN1PTJhpab9IcEwKe9xWzewvgqnMScXwJAnN7 zeyFN4H7YfPsYgF43J8RN4cPZ04JLyGxfs4T9HPi6efE08+JdwsRVUik1WiyUljNehWbK9Mo szRaVYosKTurDk3/nKfetuwG1OsclTkQRiEHAgoXB/GZxJhEIT9ZeeQoq86OV2szWY0DhVCE WMSvSKtVCukU5UE2g2VzWPX/Kkb5Bx/HcHu0OdmoGrGYvAmTI1G5wSUCaWh+dvyjJkFM/ryM bz2WHegBuzRae/nWif2hp8gvAiYvNrDbFHu7uIpvXf277fevNumdUuvYgonciBMHyicagzHj 15feB9ffEB2Pt5eKPhXZbfJRwc5JzCZXLZI45eG0re/vmp1mXVhEmIMZc2Y4Qy2u4cJXdE/f RpcrMvPD6YHGqu48x7vxe5KePVp5f9ifrnTpw3ND7r22bSZXpO3Q7pLOOI9hq73r2Pbqj/Z2 7VKzdIPdtMsevsqzFYpUf8tEC48URveFFi5v3Xczd0o3bgzZZfj0OjmpoGnoj1chSZzaFndB LkE/P98uFROaVOW6CFytUf4De6JX76gDAAA= X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFprAIsWRmVeSWpSXmKPExsWS2cA0UTd9S0CSwb5FxhZf1/9itjix6SCz xf5t/1gttuz/xm5xvHcHi8XJV+fZHNg8DrxYyO6xc9Zddo8n1zYzebzfd5UtgCWKyyYlNSez LLVI3y6BK2Pul6yCzZwVC5fwNTDeZO9i5OSQEDCR2PLyDGMXIxeHkMBqRokpex5BOR8YJVbM msYC4exnlHjw7h1YC5uAusSvzkVsIAkRgfuMEo92T2UGSTAL1EtM+bmFCcQWFrCWmLp7ISOI LSLgILHr/WsmCFtPYsvSv6wgNouAikTrjldgNq+AhcSOqevB6hkFxCS+n1rDBDFTXOLWk/lM ELcKSCzZc54ZwhaVePn4HyuErShx//tLdoh6PYkbU6ewQdjaEssWvmaGmC8ocXLmExaIekmJ gytusExgFJ2FZMUsJO2zkLTPQtK+gJFlFaN4aXFxbnpFsVFearlecWJucWleul5yfu4mRmCk nf53OHoH4+1bH/UOMTJxMB5ilOBgVhLhtUgKSBLiTUmsrEotyo8vKs1JLT7EKM3BoiTO+zJq YryQQHpiSWp2ampBahFMlomDU6qBaVbDIoujyayXWl2XKP5gX8Ad4G+bIzHRJ9+u4IPT5kkB nZeN15g+uxpzz9Tyq9tEkbX+RfxCr8refC5ec/7yVq7Z7fka/W2rLlSfCmgILb+UucwhxUTE 5uMLqXlfTskYTNAvnX31iHzd9wwnFotTb/im+HYYN/+Nv3+jb+3ioA7ei08DOdcr9Z20MwyP 59b7+CXqxA/dSRsXL/go+39r+RKW3DzdT1OaeqtfesivvJrwYaVo0rl3XXFxU39WXDl1uSAi k01nUZq85+ZfUw9+K8/nWlnk/7eeQeGzATvH4ikzazq/CW399rJDYdmhk2Vi20s2SX57XL+j 8E7avxc5snFLeNREq+TYLk7m5/z6XYmlOCPRUIu5qDgRAKU34O4jAwAA X-CMS-MailID: 20220408221711uscas1p2d64b2adae902cc51d328882980fbc50b CMS-TYPE: 301P X-CMS-RootMailID: 20220408221711uscas1p2d64b2adae902cc51d328882980fbc50b References: Received-SPF: pass client-ip=211.189.100.12; envelope-from=t.zhang2@samsung.com; helo=mailout2.w2.samsung.com X-Spam_score_int: -71 X-Spam_score: -7.2 X-Spam_bar: ------- X-Spam_report: (-7.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_HI=-5, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "ztong0001@gmail.com" , Francisco Londono , Tong Zhang Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" assert(dbs->acb) is meant to check the return value of io_func per documented in commit 6bee44ea34 ("dma: the passed io_func does not return NULL"). However, there is a chance that after calling aio_context_release(dbs->ctx); the dma_blk_cb function is called before the assertion and dbs->acb is set to NULL again at line 121. Thus when we run assert at line 181 it will fail. softmmu/dma-helpers.c:181: dma_blk_cb: Assertion `dbs->acb' failed. Reported-by: Francisco Londono Signed-off-by: Tong Zhang --- softmmu/dma-helpers.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/softmmu/dma-helpers.c b/softmmu/dma-helpers.c index 7820fec54c..cb81017928 100644 --- a/softmmu/dma-helpers.c +++ b/softmmu/dma-helpers.c @@ -177,8 +177,8 @@ static void dma_blk_cb(void *opaque, int ret) aio_context_acquire(dbs->ctx); dbs->acb = dbs->io_func(dbs->offset, &dbs->iov, dma_blk_cb, dbs, dbs->io_func_opaque); - aio_context_release(dbs->ctx); assert(dbs->acb); + aio_context_release(dbs->ctx); } static void dma_aio_cancel(BlockAIOCB *acb)