Commit d9d23a5a authored by Douglas Gilbert's avatar Douglas Gilbert Committed by Martin K. Petersen
Browse files

scsi: scsi_debug: Strengthen defer_t accesses 

Use READ_ONCE() and WRITE_ONCE() macros when accessing the
sdebug_defer::defer_t value.

Link: https://lore.kernel.org/r/20220109012853.301953-3-dgilbert@interlog.com


Signed-off-by: default avatarDouglas Gilbert <dgilbert@interlog.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 2aad3cd8

drivers/scsi/scsi_debug.c

+11 −11
Original line number Diff line number Diff line
@@ -4782,7 +4782,7 @@ static void sdebug_q_cmd_complete(struct sdebug_defer *sd_dp) 
		return;

	}

	spin_lock_irqsave(&sqp->qc_lock, iflags);

	sd_dp->defer_t = SDEB_DEFER_NONE;

	WRITE_ONCE(sd_dp->defer_t, SDEB_DEFER_NONE);

	sqcp = &sqp->qc_arr[qc_idx];

	scp = sqcp->a_cmnd;

	if (unlikely(scp == NULL)) {
@@ -5103,8 +5103,8 @@ static bool stop_queued_cmnd(struct scsi_cmnd *cmnd) 
				sqcp->a_cmnd = NULL;

				sd_dp = sqcp->sd_dp;

				if (sd_dp) {

					l_defer_t = sd_dp->defer_t;

					sd_dp->defer_t = SDEB_DEFER_NONE;

					l_defer_t = READ_ONCE(sd_dp->defer_t);

					WRITE_ONCE(sd_dp->defer_t, SDEB_DEFER_NONE);

				} else

					l_defer_t = SDEB_DEFER_NONE;

				spin_unlock_irqrestore(&sqp->qc_lock, iflags);
@@ -5145,8 +5145,8 @@ static void stop_all_queued(bool done_with_no_conn) 
				sqcp->a_cmnd = NULL;

				sd_dp = sqcp->sd_dp;

				if (sd_dp) {

					l_defer_t = sd_dp->defer_t;

					sd_dp->defer_t = SDEB_DEFER_NONE;

					l_defer_t = READ_ONCE(sd_dp->defer_t);

					WRITE_ONCE(sd_dp->defer_t, SDEB_DEFER_NONE);

				} else

					l_defer_t = SDEB_DEFER_NONE;

				spin_unlock_irqrestore(&sqp->qc_lock, iflags);
@@ -5627,7 +5627,7 @@ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip, 
				sd_dp->sqa_idx = sqp - sdebug_q_arr;

				sd_dp->qc_idx = k;

			}

			sd_dp->defer_t = SDEB_DEFER_POLL;

			WRITE_ONCE(sd_dp->defer_t, SDEB_DEFER_POLL);

			spin_unlock_irqrestore(&sqp->qc_lock, iflags);

		} else {

			if (!sd_dp->init_hrt) {
@@ -5639,7 +5639,7 @@ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip, 
				sd_dp->sqa_idx = sqp - sdebug_q_arr;

				sd_dp->qc_idx = k;

			}

			sd_dp->defer_t = SDEB_DEFER_HRT;

			WRITE_ONCE(sd_dp->defer_t, SDEB_DEFER_HRT);

			/* schedule the invocation of scsi_done() for a later time */

			hrtimer_start(&sd_dp->hrt, kt, HRTIMER_MODE_REL_PINNED);

		}
@@ -5658,7 +5658,7 @@ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip, 
				sd_dp->sqa_idx = sqp - sdebug_q_arr;

				sd_dp->qc_idx = k;

			}

			sd_dp->defer_t = SDEB_DEFER_POLL;

			WRITE_ONCE(sd_dp->defer_t, SDEB_DEFER_POLL);

			spin_unlock_irqrestore(&sqp->qc_lock, iflags);

		} else {

			if (!sd_dp->init_wq) {
@@ -5668,7 +5668,7 @@ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip, 
				sd_dp->qc_idx = k;

				INIT_WORK(&sd_dp->ew.work, sdebug_q_cmd_wq_complete);

			}

			sd_dp->defer_t = SDEB_DEFER_WQ;

			WRITE_ONCE(sd_dp->defer_t, SDEB_DEFER_WQ);

			schedule_work(&sd_dp->ew.work);

		}

		if (sdebug_statistics)
@@ -7436,7 +7436,7 @@ static int sdebug_blk_mq_poll(struct Scsi_Host *shost, unsigned int queue_num) 
			       queue_num, qc_idx, __func__);

			break;

		}

		if (sd_dp->defer_t == SDEB_DEFER_POLL) {

		if (READ_ONCE(sd_dp->defer_t) == SDEB_DEFER_POLL) {

			if (kt_from_boot < sd_dp->cmpl_ts)

				continue;
@@ -7470,7 +7470,7 @@ static int sdebug_blk_mq_poll(struct Scsi_Host *shost, unsigned int queue_num) 
			else

				atomic_set(&retired_max_queue, k + 1);

		}

		sd_dp->defer_t = SDEB_DEFER_NONE;

		WRITE_ONCE(sd_dp->defer_t, SDEB_DEFER_NONE);

		spin_unlock_irqrestore(&sqp->qc_lock, iflags);

		scsi_done(scp); /* callback to mid level */

		spin_lock_irqsave(&sqp->qc_lock, iflags);