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 D335FC432BE for ; Mon, 23 Aug 2021 11:32:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AB31C61361 for ; Mon, 23 Aug 2021 11:32:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236237AbhHWLcq (ORCPT ); Mon, 23 Aug 2021 07:32:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45478 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234997AbhHWLcp (ORCPT ); Mon, 23 Aug 2021 07:32:45 -0400 Received: from mail-pj1-x1033.google.com (mail-pj1-x1033.google.com [IPv6:2607:f8b0:4864:20::1033]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9A0E1C061575; Mon, 23 Aug 2021 04:32:00 -0700 (PDT) Received: by mail-pj1-x1033.google.com with SMTP id oa17so11767538pjb.1; Mon, 23 Aug 2021 04:32:00 -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=fpst6WuiQvBEVS+61khIq6Qn59v3bAx5r84xd9neoMk=; b=ZXFZtnmlRbRNWTqvikszENKBieQd35ESzS9296CIGG2zWnHk3BOBuc1+xL4HEDrYcD EeRCMwimMOt0yiiACpgUh1cNb9wnSoFjf6YD+HufOuBxpFGn1w+P/NKuF35uJIsQ9voJ RlhQjnuEEKgs3Q2YiFz6Bfh2wcnl2WoVqu2tWwgIht4ygvn4zaf7VlglnNVJphqXXG22 zjVgBMokhcYAqoDJRakUaH5HDuTtF68MLKFNP8br+IZsKjlpxvOsnIQda0Y/qX/VYaQj fngsPFhAiRqUtiz+dQllgjCXHJnEzGYkt5i9W2GJAReNIBSatkdELmm2Fc1iNSgQyN0C fIew== 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=fpst6WuiQvBEVS+61khIq6Qn59v3bAx5r84xd9neoMk=; b=t1b47HXdLBVBH0uFPLv6swT/6/CJ2jSJu9Ej8ghO/4C0WC+ZZpPnR/KdyNXFkGYEL6 hpHejw9vQ10OricdpjO/vZZtqMXTONca2i7icj0K4gewbBtYwxNiEIr6C3uiVraNkzHb UBH7NVWipGgNpVmazRfg3r9BeuMLV6uarOhDM7b4BZOt4lN1+sPzb5Ut3h4kv0BnPWFz N7hCyhfG+bUYsK+/nmi6I6OTfqlbMjQMJcGdEEGLezk2uylUWM3AZrVnpjjV7nBZTdZp r8p7tbsts4TDhvWV/3ul9bDgoB3A+HiU3g7cJoe4cuIsxyQV7I5ChrgRg0yobYJkq1VV rgIA== X-Gm-Message-State: AOAM531VNpIoHRCYc/TTzfm/HvTJRVig8CAZOQMCZdlbYafmVBRibKsE qDPHfbazchq81dd2lZTgNNrXiphweS0= X-Google-Smtp-Source: ABdhPJwT6uVwEp9Yshmg5oZSqg1c0Grxk4iqgeSykqU8fgbSWW+ByTwDeFMm2hlAeheMspfcWEfclg== X-Received: by 2002:a17:902:8c83:b029:129:17e5:a1cc with SMTP id t3-20020a1709028c83b029012917e5a1ccmr28041269plo.49.1629718319649; Mon, 23 Aug 2021 04:31:59 -0700 (PDT) Received: from [10.18.0.46] ([85.203.23.7]) by smtp.gmail.com with ESMTPSA id k25sm15741438pfa.213.2021.08.23.04.31.56 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 23 Aug 2021 04:31:59 -0700 (PDT) From: Jia-Ju Bai Subject: [BUG] scsi: lpfc: possible ABBCCA deadlock involving three threads To: james.smart@broadcom.com, dick.kennedy@broadcom.com, jejb@linux.ibm.com, martin.petersen@oracle.com Cc: linux-scsi@vger.kernel.org, linux-kernel Message-ID: Date: Mon, 23 Aug 2021 19:31:55 +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 ABBCCA deadlock in the lpfc driver in Linux 5.10: lpfc_els_flush_cmd()   spin_lock(&pring->ring_lock); --> line 8124 (Lock A)   lpfc_sli_cancel_iocbs()     lpfc_sli_release_iocbq()       spin_lock_irqsave(&phba->hbalock, iflags); --> line 1384 (Lock B) lpfc_sli_abort_taskmgmt()   spin_lock_irqsave(&phba->hbalock, iflags); --> line 11812 (Lock B)   spin_lock(&lpfc_cmd->buf_lock); --> line 11830 (Lock C) lpfc_abort_handler()   spin_lock(&lpfc_cmd->buf_lock); --> line 4760 (Lock C)   spin_lock(&pring_s4->ring_lock); --> line 4777 (Lock A) When lpfc_els_flush_cmd(), lpfc_sli_abort_taskmgmt() and lpfc_abort_handler() 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