From patchwork Thu Jul 22 03:34:35 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bart Van Assche X-Patchwork-Id: 484225 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 BF29CC636C8 for ; Thu, 22 Jul 2021 03:35:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A926F6124B for ; Thu, 22 Jul 2021 03:35:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231169AbhGVCzR (ORCPT ); Wed, 21 Jul 2021 22:55:17 -0400 Received: from mail-pj1-f52.google.com ([209.85.216.52]:40896 "EHLO mail-pj1-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231156AbhGVCzQ (ORCPT ); Wed, 21 Jul 2021 22:55:16 -0400 Received: by mail-pj1-f52.google.com with SMTP id u9-20020a17090a1f09b029017554809f35so2283213pja.5 for ; Wed, 21 Jul 2021 20:35:52 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=Fb2RY2/wstAyuLtAtIt20ooGDzmuUYR3su3nCi4Jx+0=; b=aSXbGIMOHoW8+AEiGtvd1qQg1jpkvHq92vDkdIX4fryw+fkAVdO9UF0uKZeeUb5Sxd gryboD4Q9Q8t1/dnMA7VqafeJ/vXg+7ia2J48+AQVtPAX14e+APC/LMfMEAXDEUx4Jd4 CcQjDlfeH57LkEqU/KvGL0Ba312L1l/gElUkGgNG8CBbXHiGcUoWe5LD1TfkY252USvL WB4ao3a3Wo3aY7kfP6aRs8xMLmkxm/sc1LhR3PaACIS0+EoB9bAuJ++Iogx75CuY60ok 3nqhU0bFm5TbZcSbdILMtaSLBs4TFKRnYKA2jmtSW63aPskTj1j8nGKS2leP5BTeW8YY MUzg== X-Gm-Message-State: AOAM531LeKjYljlO1ZbwDKPCx/g7lOEoWdd4F/H8RVtUxrsM/LbFEpyk 0hQV0G9f+RLom72WBQ8V27g= X-Google-Smtp-Source: ABdhPJxB2H+SLTrb6ekNeROP4kLxnutyY2vInxEcC+U8rwzZbCVNDoN6kCjhJr65quXLVZo6h34Lww== X-Received: by 2002:a62:be18:0:b029:318:df2e:c17c with SMTP id l24-20020a62be180000b0290318df2ec17cmr40368164pff.30.1626924951670; Wed, 21 Jul 2021 20:35:51 -0700 (PDT) Received: from asus.hsd1.ca.comcast.net ([2601:647:4000:d7:30e2:954a:f4a0:3224]) by smtp.gmail.com with ESMTPSA id n6sm32060258pgb.60.2021.07.21.20.35.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 21 Jul 2021 20:35:51 -0700 (PDT) From: Bart Van Assche To: "Martin K . Petersen" Cc: linux-scsi@vger.kernel.org, Jaegeuk Kim , Bart Van Assche , Adrian Hunter , Stanley Chu , Can Guo , Asutosh Das , Avri Altman , "James E.J. Bottomley" , Matthias Brugger , Bean Huo Subject: [PATCH v3 14/18] scsi: ufs: Fix the SCSI abort handler Date: Wed, 21 Jul 2021 20:34:35 -0700 Message-Id: <20210722033439.26550-15-bvanassche@acm.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210722033439.26550-1-bvanassche@acm.org> References: <20210722033439.26550-1-bvanassche@acm.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Make the following changes in ufshcd_abort(): - Return FAILED instead of SUCCESS if the abort handler notices that a SCSI command has already been completed. Returning SUCCESS in this case triggers a use-after-free and may trigger a kernel crash. - Fix the code for aborting SCSI commands submitted to a WLUN. The current approach for aborting SCSI commands that have been submitted to a WLUN and that timed out is as follows: - Report to the SCSI core that the command has completed successfully. Let the block layer free any data buffers associated with the command. - Mark the command as outstanding in 'outstanding_reqs'. - If the block layer tries to reuse the tag associated with the aborted command, busy-wait until the tag is freed. This approach can result in: - Memory corruption if the controller accesses the data buffer after the block layer has freed the associated data buffers. - A race condition if ufshcd_queuecommand() or ufshcd_exec_dev_cmd() checks the bit that corresponds to an aborted command in 'outstanding_reqs' after it has been cleared and before it is reset. - High energy consumption if ufshcd_queuecommand() repeatedly returns SCSI_MLQUEUE_HOST_BUSY. Fix this by reporting to the SCSI error handler that aborting a SCSI command failed if the SCSI command was submitted to a WLUN. Cc: Adrian Hunter Cc: Stanley Chu Cc: Can Guo Cc: Asutosh Das Cc: Avri Altman Fixes: 7a7e66c65d41 ("scsi: ufs: Fix a race condition between ufshcd_abort() and eh_work()") Signed-off-by: Bart Van Assche Reviewed-by: Bean Huo --- drivers/scsi/ufs/ufshcd.c | 54 ++++++++++++++------------------------- 1 file changed, 19 insertions(+), 35 deletions(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index a3ad83a3bae0..c35e101c5834 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -2724,15 +2724,6 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd) WARN_ON(ufshcd_is_clkgating_allowed(hba) && (hba->clk_gating.state != CLKS_ON)); - if (unlikely(test_bit(tag, &hba->outstanding_reqs))) { - if (hba->pm_op_in_progress) - set_host_byte(cmd, DID_BAD_TARGET); - else - err = SCSI_MLQUEUE_HOST_BUSY; - ufshcd_release(hba); - goto out; - } - lrbp = &hba->lrb[tag]; WARN_ON(lrbp->cmd); lrbp->cmd = cmd; @@ -2929,11 +2920,6 @@ static int ufshcd_exec_dev_cmd(struct ufs_hba *hba, req->timeout = msecs_to_jiffies(2 * timeout); blk_mq_start_request(req); - if (unlikely(test_bit(tag, &hba->outstanding_reqs))) { - err = -EBUSY; - goto out; - } - lrbp = &hba->lrb[tag]; WARN_ON(lrbp->cmd); err = ufshcd_compose_dev_cmd(hba, lrbp, cmd_type, tag); @@ -6922,19 +6908,19 @@ static int ufshcd_abort(struct scsi_cmnd *cmd) unsigned int tag = cmd->request->tag; struct ufshcd_lrb *lrbp = &hba->lrb[tag]; unsigned long flags; - int err = 0; + int err = FAILED; u32 reg; WARN_ONCE(tag < 0, "Invalid tag %d\n", tag); ufshcd_hold(hba, false); reg = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL); - /* If command is already aborted/completed, return SUCCESS */ + /* If command is already aborted/completed, return FAILED. */ if (!(test_bit(tag, &hba->outstanding_reqs))) { dev_err(hba->dev, "%s: cmd at tag %d already completed, outstanding=0x%lx, doorbell=0x%x\n", __func__, tag, hba->outstanding_reqs, reg); - goto out; + goto release; } /* Print Transfer Request of aborted task */ @@ -6963,7 +6949,8 @@ static int ufshcd_abort(struct scsi_cmnd *cmd) dev_err(hba->dev, "%s: cmd was completed, but without a notifying intr, tag = %d", __func__, tag); - goto cleanup; + __ufshcd_transfer_req_compl(hba, 1UL << tag); + goto release; } /* @@ -6976,36 +6963,33 @@ static int ufshcd_abort(struct scsi_cmnd *cmd) */ if (lrbp->lun == UFS_UPIU_UFS_DEVICE_WLUN) { ufshcd_update_evt_hist(hba, UFS_EVT_ABORT, lrbp->lun); - __ufshcd_transfer_req_compl(hba, (1UL << tag)); - set_bit(tag, &hba->outstanding_reqs); + spin_lock_irqsave(host->host_lock, flags); hba->force_reset = true; ufshcd_schedule_eh_work(hba); spin_unlock_irqrestore(host->host_lock, flags); - goto out; + goto release; } /* Skip task abort in case previous aborts failed and report failure */ - if (lrbp->req_abort_skip) - err = -EIO; - else - err = ufshcd_try_to_abort_task(hba, tag); + if (lrbp->req_abort_skip) { + dev_err(hba->dev, "%s: skipping abort\n", __func__); + ufshcd_set_req_abort_skip(hba, hba->outstanding_reqs); + goto release; + } - if (!err) { -cleanup: - __ufshcd_transfer_req_compl(hba, (1UL << tag)); -out: - err = SUCCESS; - } else { + err = ufshcd_try_to_abort_task(hba, tag); + if (err) { dev_err(hba->dev, "%s: failed with err %d\n", __func__, err); ufshcd_set_req_abort_skip(hba, hba->outstanding_reqs); err = FAILED; + goto release; } - /* - * This ufshcd_release() corresponds to the original scsi cmd that got - * aborted here (as we won't get any IRQ for it). - */ + err = SUCCESS; + +release: + /* Matches the ufshcd_hold() call at the start of this function. */ ufshcd_release(hba); return err; }