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From: Bart Van Assche <bvanassche@acm.org>
To: "Martin K . Petersen" <martin.petersen@oracle.com>,
	"James E . J . Bottomley" <jejb@linux.vnet.ibm.com>
Cc: linux-scsi@vger.kernel.org, Bart Van Assche <bvanassche@acm.org>,
	Bean Huo <beanhuo@micron.com>, Can Guo <cang@codeaurora.org>,
	Avri Altman <avri.altman@wdc.com>,
	Stanley Chu <stanley.chu@mediatek.com>,
	Tomas Winkler <tomas.winkler@intel.com>
Subject: [PATCH 4/6] ufs: Fix a race condition in the tracing code
Date: Tue, 24 Dec 2019 14:02:46 -0800	[thread overview]
Message-ID: <20191224220248.30138-5-bvanassche@acm.org> (raw)
In-Reply-To: <20191224220248.30138-1-bvanassche@acm.org>

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 <beanhuo@micron.com>
Cc: Can Guo <cang@codeaurora.org>
Cc: Avri Altman <avri.altman@wdc.com>
Cc: Stanley Chu <stanley.chu@mediatek.com>
Cc: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 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");
 	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");
 }
 
 /**

  parent reply	other threads:[~2019-12-24 22:03 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-24 22:02 [PATCH 0/6] Six UFS patches Bart Van Assche
2019-12-24 22:02 ` [PATCH 1/6] ufs: Fix indentation in ufshcd_query_attr_retry() Bart Van Assche
2019-12-25  7:16   ` Stanley Chu
2019-12-25  8:17   ` Can Guo
2019-12-27  1:13   ` Alim Akhtar
2019-12-24 22:02 ` [PATCH 2/6] ufs: Make ufshcd_add_command_trace() easier to read Bart Van Assche
2019-12-25  7:16   ` Stanley Chu
2019-12-25  8:17   ` Can Guo
2019-12-27  1:17   ` Alim Akhtar
2019-12-24 22:02 ` [PATCH 3/6] ufs: Make ufshcd_prepare_utp_scsi_cmd_upiu() " Bart Van Assche
2019-12-25  7:17   ` Stanley Chu
2019-12-25  8:18   ` Can Guo
2019-12-24 22:02 ` Bart Van Assche [this message]
2019-12-25 10:59   ` [PATCH 4/6] ufs: Fix a race condition in the tracing code Can Guo
2019-12-26 17:35     ` Bart Van Assche
2019-12-27  5:50       ` Can Guo
2019-12-27  1:21   ` Alim Akhtar
2019-12-24 22:02 ` [PATCH 5/6] ufs: Remove superfluous memory barriers Bart Van Assche
2019-12-25 10:31   ` Can Guo
2019-12-26 17:36     ` Bart Van Assche
2019-12-24 22:02 ` [PATCH 6/6] ufs: Remove the SCSI timeout handler Bart Van Assche
2019-12-25 11:02   ` Can Guo
2019-12-27  1:24   ` Alim Akhtar
2020-05-28  9:47   ` Can Guo
2020-05-28 16:12     ` Bart Van Assche
2020-05-29  1:39       ` Can Guo
2020-05-29  3:56         ` Bart Van Assche
2020-01-03  2:58 ` [PATCH 0/6] Six UFS patches Martin K. Petersen

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