Commit eacf36f5 authored Dec 24, 2019 by Bart Van Assche Committed by Martin K. Petersen Jan 02, 2020

scsi: ufs: Fix a race condition in the tracing code

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>
Link: https://lore.kernel.org/r/20191224220248.30138-5-bvanassche@acm.org

Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

parent 1b21b8f0

drivers/scsi/ufs/ufshcd.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1860,12 +1860,12 @@ 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");
		}

		/**

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