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=-4.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 B1230C432BE for ; Mon, 23 Aug 2021 11:50:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9981561378 for ; Mon, 23 Aug 2021 11:50:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236564AbhHWLvU (ORCPT ); Mon, 23 Aug 2021 07:51:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49858 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235337AbhHWLvT (ORCPT ); Mon, 23 Aug 2021 07:51:19 -0400 Received: from mail-pl1-x62a.google.com (mail-pl1-x62a.google.com [IPv6:2607:f8b0:4864:20::62a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E1CE9C061575; Mon, 23 Aug 2021 04:50:36 -0700 (PDT) Received: by mail-pl1-x62a.google.com with SMTP id e15so9983832plh.8; Mon, 23 Aug 2021 04:50:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:subject:to:cc:message-id:date:user-agent:mime-version :content-transfer-encoding:content-language; bh=O5DM1sJkMAZ9pupJ/zl5vudKhULLO2p/SdJWZo+B+eo=; b=PJvNXb8mSnm9cemZbK+4j70aWxx4Lee2OayaWVuYrLvVhGvzVf0+35TDcdzhEkKyiC thE3GiTXw8a8tWqL5XAZbWFES6Q7ZfET23jlCT7QrOXtoxXRQJdBaH9Kdr0u4VG9KqV8 1z8yyYn+rPrIKImrryJUbeZNy6e9fUeyKcUwisAoAxxBLhD5zdqURfMVxKyyDXqvGBUq j8RVMJoTNRhuzYEWXpb/qVn8/TUhYYUzn+tewG6e+f0/69GTNzkCWEhm9Kd6p+43TXfL uzAtO5RxSlYKjiHKikc9VzfzZk6mddt3QeT+lkAsoJ/lYwvHBD2bF0HsHVP74P5BkFsW lRVQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:subject:to:cc:message-id:date:user-agent :mime-version:content-transfer-encoding:content-language; bh=O5DM1sJkMAZ9pupJ/zl5vudKhULLO2p/SdJWZo+B+eo=; b=oboj3uN+u8qAAxbk+8EqY6IFtE4SHLzQxnl2okJ2wuoWDNwoODZa94O9DDCSWVD5J5 JVna4xo+dnD29jWEPPzx/Aqu4Z6rhaQLeFJMtJNpA1bpz+zIToA6Fp7F+jwKdFUxURGX bKS2vIpwzqqEPMw+T3Z8Ea/+0NpcvDERx1KvIbb8fTdTLdELOypjnTxmkX3wWF8pwzL7 aUk7NMM0sdOkeU23xeoWn7WW4Ufsuuxw8WfEsFATjAuR8IPNeUjw9YhE7U0OegG/C8jQ Z0Fq9h0vkKT+iwcCVNC6peWA05CkKdDgPDBQIST1330mbFfXVZe9eg90D8sHYT5L5VmN u78g== X-Gm-Message-State: AOAM532kz+4RTqlNgkubvhBJbABzFFkO+q/OrvafoNLXuzQgp6IQSOGb cTp+8B8MUZITw5SMVgvNN+ExSwDvXog= X-Google-Smtp-Source: ABdhPJyoKd8/N5yLCg/VKSt+JpWXIGEWPIPoRYiqsQg1ld8auxvdPPOsCmXasF0S+D02ad5sc+tvHQ== X-Received: by 2002:a17:902:6b47:b0:12f:6c5f:ab4f with SMTP id g7-20020a1709026b4700b0012f6c5fab4fmr20997699plt.17.1629719436043; Mon, 23 Aug 2021 04:50:36 -0700 (PDT) Received: from [10.136.0.70] ([45.145.248.194]) by smtp.gmail.com with ESMTPSA id n30sm15965384pfv.87.2021.08.23.04.50.33 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 23 Aug 2021 04:50:35 -0700 (PDT) From: Jia-Ju Bai Subject: [BUG] media: platform: qcom: venus: possible ABBA deadlock in venus_event_notify() and venus_helper_vb2_buf_queue() To: stanimir.varbanov@linaro.org, agross@kernel.org, bjorn.andersson@linaro.org, Mauro Carvalho Chehab Cc: Linux Media Mailing List , linux-arm-msm@vger.kernel.org, linux-kernel Message-ID: Date: Mon, 23 Aug 2021 19:50:31 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, My static analysis tool reports a possible ABBA deadlock in the venus driver in Linux 5.10: venus_event_notify()   mutex_lock(&core->lock); --> line 37 (Lock A)   vdec_event_notify() --> via a function pointer "inst->ops->event_notify(...)"   vdec_event_change()     mutex_lock(&inst->lock); --> line 1301 (Lock B) venus_helper_vb2_buf_queue()   mutex_lock(&inst->lock); --> line 1346 (Lock B)   session_process_buf()     venus_pm_load_scale()       load_scale_v4() via a function pointer "core->pm_ops->load_scale(...)"         mutex_lock(&core->lock); --> line 966 (Lock A) Besides, if "core->pm_ops->load_scale(...)" is load_scale_v1(): load_scale_v1()   load_per_type()     mutex_lock(&core->lock); --> line 150 (Lock A) When venus_event_notify() and venus_helper_vb2_buf_queue() are concurrently executed, the deadlock can occur. I am not quite sure whether this possible deadlock is real and how to fix it if it is real. Any feedback would be appreciated, thanks Reported-by: TOTE Robot Best wishes, Jia-Ju Bai