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=-6.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=ham 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 47078C2D0DA for ; Wed, 25 Dec 2019 11:00:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0B2AA2071E for ; Wed, 25 Dec 2019 10:59:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="P39wrXvU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726185AbfLYK77 (ORCPT ); Wed, 25 Dec 2019 05:59:59 -0500 Received: from mail25.static.mailgun.info ([104.130.122.25]:15364 "EHLO mail25.static.mailgun.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726025AbfLYK77 (ORCPT ); Wed, 25 Dec 2019 05:59:59 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1577271598; h=Message-ID: References: In-Reply-To: Subject: Cc: To: From: Date: Content-Transfer-Encoding: Content-Type: MIME-Version: Sender; bh=JujXawWBTNE0kVjfdvuHufQl4/jIQvF0xYlEYGihM20=; b=P39wrXvUFtthzj1YvCuGGOZEfZWt6MXE0TugOuxCLybRYzFwLgCGbKybKovgACIF1vCu9KeS Hbq8BtS19CiC9stFtloQnGAzlHi6EvFKk1ElZPo043icTu2a3GS1pMcBfKGVZToC8uJdbOxH V0C22XmuYAuMzwL6tB3BHMH/TP0= X-Mailgun-Sending-Ip: 104.130.122.25 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 mxa.mailgun.org with ESMTP id 5e03412d.7f828a2999d0-smtp-out-n02; Wed, 25 Dec 2019 10:59:57 -0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 4811FC4479F; Wed, 25 Dec 2019 10:59:56 +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 4717DC43383; Wed, 25 Dec 2019 10:59:55 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Wed, 25 Dec 2019 18:59:55 +0800 From: Can Guo To: Bart Van Assche Cc: "Martin K . Petersen" , "James E . J . Bottomley" , linux-scsi@vger.kernel.org, Bean Huo , Avri Altman , Stanley Chu , Tomas Winkler Subject: Re: [PATCH 4/6] ufs: Fix a race condition in the tracing code In-Reply-To: <20191224220248.30138-5-bvanassche@acm.org> References: <20191224220248.30138-1-bvanassche@acm.org> <20191224220248.30138-5-bvanassche@acm.org> Message-ID: <39b63e90a34a294957c89bd30d0e4912@codeaurora.org> X-Sender: cang@codeaurora.org User-Agent: Roundcube Webmail/1.3.9 Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org On 2019-12-25 06:02, Bart Van Assche wrote: > Starting execution of a command before tracing a command may cause the > completion handler to free data while it is being traced. Fix this race > by tracing a command before it is submitted. > > Cc: Bean Huo > Cc: Can Guo > Cc: Avri Altman > Cc: Stanley Chu > Cc: Tomas Winkler > Signed-off-by: Bart Van Assche > --- > drivers/scsi/ufs/ufshcd.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c > index 80b028ba39e9..4d9bb1932b39 100644 > --- a/drivers/scsi/ufs/ufshcd.c > +++ b/drivers/scsi/ufs/ufshcd.c > @@ -1875,12 +1875,12 @@ void ufshcd_send_command(struct ufs_hba *hba, > unsigned int task_tag) > { > hba->lrb[task_tag].issue_time_stamp = ktime_get(); > hba->lrb[task_tag].compl_time_stamp = ktime_set(0, 0); > + ufshcd_add_command_trace(hba, task_tag, "send"); How about moving it after __set_bit(task_tag, &hba->outstanding_reqs);? Thanks, Can Guo. > ufshcd_clk_scaling_start_busy(hba); > __set_bit(task_tag, &hba->outstanding_reqs); > ufshcd_writel(hba, 1 << task_tag, REG_UTP_TRANSFER_REQ_DOOR_BELL); > /* Make sure that doorbell is committed immediately */ > wmb(); > - ufshcd_add_command_trace(hba, task_tag, "send"); > } > > /**