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=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,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 0D9D1C48BCF for ; Thu, 10 Jun 2021 00:54:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D5F9A61182 for ; Thu, 10 Jun 2021 00:54:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229770AbhFJA4r (ORCPT ); Wed, 9 Jun 2021 20:56:47 -0400 Received: from m43-7.mailgun.net ([69.72.43.7]:35265 "EHLO m43-7.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229507AbhFJA4r (ORCPT ); Wed, 9 Jun 2021 20:56:47 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1623286491; h=Message-ID: References: In-Reply-To: Subject: Cc: To: From: Date: Content-Transfer-Encoding: Content-Type: MIME-Version: Sender; bh=IRiJ5K8YisVDKjZxsTxSkq8Yob/1/IJG4BZVkroF3gA=; b=Mq0YTIz5QH5vT2iuAINxCi7/YB+HQVt4mV3lwkghP28haafG5j6iUFGetCeIHsFQmJVxW25e p8SA+GBMI4p/mzLlXavmv+RkFO32tlySCfUIoyz0uDT6tCRw1XeV8rw8xCA3iOWsyi48xr7w aYd/e49K+kLMgghGNoBuYrufMIQ= X-Mailgun-Sending-Ip: 69.72.43.7 X-Mailgun-Sid: WyJlNmU5NiIsICJsaW51eC1zY3NpQHZnZXIua2VybmVsLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n06.prod.us-east-1.postgun.com with SMTP id 60c162c7f726fa418886d525 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Thu, 10 Jun 2021 00:54:31 GMT Sender: cang=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 680CCC433D3; Thu, 10 Jun 2021 00:54:30 +0000 (UTC) Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: cang) by smtp.codeaurora.org (Postfix) with ESMTPSA id 24325C433F1; Thu, 10 Jun 2021 00:54:29 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Thu, 10 Jun 2021 08:54:29 +0800 From: Can Guo To: Dan Carpenter Cc: linux-scsi@vger.kernel.org Subject: Re: [bug report] scsi: ufs: Optimize host lock on transfer requests send/compl paths In-Reply-To: References: Message-ID: <6158235591271fe789dd86f76b360145@codeaurora.org> X-Sender: cang@codeaurora.org User-Agent: Roundcube Webmail/1.3.9 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Hi Dan, On 2021-06-09 19:01, Dan Carpenter wrote: > Hello Can Guo, > > The patch a45f937110fa: "scsi: ufs: Optimize host lock on transfer > requests send/compl paths" from May 24, 2021, leads to the following > static checker warning: > > drivers/scsi/ufs/ufshcd.c:2998 ufshcd_exec_dev_cmd() > error: potentially dereferencing uninitialized 'lrbp'. > I uploaded a fix yesterday - https://lore.kernel.org/patchwork/patch/1443774/ Thanks for reporting it and sorry for the disturb. Regards, Can Guo. > drivers/scsi/ufs/ufshcd.c > 2948 static int ufshcd_exec_dev_cmd(struct ufs_hba *hba, > 2949 enum dev_cmd_type cmd_type, int timeout) > 2950 { > 2951 struct request_queue *q = hba->cmd_queue; > 2952 struct request *req; > 2953 struct ufshcd_lrb *lrbp; > ^^^^ > > 2954 int err; > 2955 int tag; > 2956 struct completion wait; > 2957 > 2958 down_read(&hba->clk_scaling_lock); > 2959 > 2960 /* > 2961 * Get free slot, sleep if slots are unavailable. > 2962 * Even though we use wait_event() which sleeps > indefinitely, > 2963 * the maximum wait time is bounded by SCSI request > timeout. > 2964 */ > 2965 req = blk_get_request(q, REQ_OP_DRV_OUT, 0); > 2966 if (IS_ERR(req)) { > 2967 err = PTR_ERR(req); > 2968 goto out_unlock; > 2969 } > 2970 tag = req->tag; > 2971 WARN_ON_ONCE(!ufshcd_valid_tag(hba, tag)); > 2972 /* Set the timeout such that the SCSI error handler is > not activated. */ > 2973 req->timeout = msecs_to_jiffies(2 * timeout); > 2974 blk_mq_start_request(req); > 2975 > 2976 if (unlikely(test_bit(tag, &hba->outstanding_reqs))) { > 2977 err = -EBUSY; > 2978 goto out; > ^^^^^^^^ > > 2979 } > 2980 > 2981 init_completion(&wait); > 2982 lrbp = &hba->lrb[tag]; > > This used to be initialized before the goto > > 2983 WARN_ON(lrbp->cmd); > 2984 err = ufshcd_compose_dev_cmd(hba, lrbp, cmd_type, tag); > 2985 if (unlikely(err)) > 2986 goto out_put_tag; > 2987 > 2988 hba->dev_cmd.complete = &wait; > 2989 > 2990 ufshcd_add_query_upiu_trace(hba, UFS_QUERY_SEND, > lrbp->ucd_req_ptr); > 2991 /* Make sure descriptors are ready before ringing the > doorbell */ > 2992 wmb(); > 2993 > 2994 ufshcd_send_command(hba, tag); > 2995 err = ufshcd_wait_for_dev_cmd(hba, lrbp, timeout); > 2996 out: > 2997 ufshcd_add_query_upiu_trace(hba, err ? UFS_QUERY_ERR : > UFS_QUERY_COMP, > 2998 (struct utp_upiu_req > *)lrbp->ucd_rsp_ptr); > > ^^^^^^^^^^^^^^^^^ > > 2999 > 3000 out_put_tag: > 3001 blk_put_request(req); > 3002 out_unlock: > 3003 up_read(&hba->clk_scaling_lock); > 3004 return err; > 3005 } > > regards, > dan carpenter