From patchwork Fri Mar 18 09:51:36 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "S.J. Wang" X-Patchwork-Id: 12785110 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C4F1CC433F5 for ; Fri, 18 Mar 2022 10:01:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234790AbiCRKCf (ORCPT ); Fri, 18 Mar 2022 06:02:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47628 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234079AbiCRKCf (ORCPT ); Fri, 18 Mar 2022 06:02:35 -0400 Received: from inva020.nxp.com (inva020.nxp.com [92.121.34.13]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 98C15100E09; Fri, 18 Mar 2022 03:01:16 -0700 (PDT) Received: from inva020.nxp.com (localhost [127.0.0.1]) by inva020.eu-rdc02.nxp.com (Postfix) with ESMTP id 1DE441A1F2A; Fri, 18 Mar 2022 11:01:15 +0100 (CET) Received: from aprdc01srsp001v.ap-rdc01.nxp.com (aprdc01srsp001v.ap-rdc01.nxp.com [165.114.16.16]) by inva020.eu-rdc02.nxp.com (Postfix) with ESMTP id D3A261A1F1D; Fri, 18 Mar 2022 11:01:14 +0100 (CET) Received: from localhost.localdomain (shlinux2.ap.freescale.net [10.192.224.44]) by aprdc01srsp001v.ap-rdc01.nxp.com (Postfix) with ESMTP id 83AEC183AD67; Fri, 18 Mar 2022 18:01:13 +0800 (+08) From: Shengjiu Wang To: bjorn.andersson@linaro.org, mathieu.poirier@linaro.org Cc: linux-remoteproc@vger.kernel.org, linux-kernel@vger.kernel.org, shengjiu.wang@gmail.com Subject: [PATCH] remoteproc: core: check rproc->power value before decreasing it Date: Fri, 18 Mar 2022 17:51:36 +0800 Message-Id: <1647597096-5480-1-git-send-email-shengjiu.wang@nxp.com> X-Mailer: git-send-email 2.7.4 X-Virus-Scanned: ClamAV using ClamSMTP Precedence: bulk List-ID: X-Mailing-List: linux-remoteproc@vger.kernel.org There are possibility that two 'stop' operation happen in parallel, then the rproc->power may be decreased to -1, that this reference count will be in wrong state. So check rproc->power to make sure it is larger than zero before decreasing it. Signed-off-by: Shengjiu Wang --- drivers/remoteproc/remoteproc_core.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c index c510125769b9..84e065ad8743 100644 --- a/drivers/remoteproc/remoteproc_core.c +++ b/drivers/remoteproc/remoteproc_core.c @@ -2075,6 +2075,9 @@ int rproc_shutdown(struct rproc *rproc) return ret; } + if (atomic_read(&rproc->power) <= 0) + goto out; + /* if the remote proc is still needed, bail out */ if (!atomic_dec_and_test(&rproc->power)) goto out;