diff options
| author | Alice Chao <alice.chao@mediatek.com> | 2023-10-24 10:43:21 +0200 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2023-10-25 04:43:24 +0200 |
| commit | a5181c8955145431e809158ad370258f77c3b77f (patch) | |
| tree | 5cb8edf05a243170f49c3cebc3d3a7a8ae5bf850 /drivers/ufs | |
| parent | scsi: megaraid: Fix up debug message in megaraid_abort_and_reset() (diff) | |
| download | linux-a5181c8955145431e809158ad370258f77c3b77f.tar.xz linux-a5181c8955145431e809158ad370258f77c3b77f.zip | |
scsi: ufs: core: Fix race between force complete and ISR
While error handler force complete command (Thread A) and completion IRQ
raising (Thread B) of the same command, it may cause race condition.
Below is racing step (from 1 to 6):
ufshcd_mcq_compl_pending_transfer (Thread A)
1 if (cmd && !test_bit(SCMD_STATE_COMPLETE, &cmd->state)) {
5 spin_lock_irqsave(&hwq->cq_lock, flags); // wait lock release
set_host_byte(cmd, DID_REQUEUE);
6 ufshcd_release_scsi_cmd(hba, lrbp); // access null pointer
scsi_done(cmd);
spin_unlock_irqrestore(&hwq->cq_lock, flags);
}
ufshcd_mcq_poll_cqe_lock (Thread B)
2 spin_lock_irqsave(&hwq->cq_lock, flags);
ufshcd_mcq_poll_cqe_nolock()
ufshcd_compl_one_cqe()
3 ufshcd_release_scsi_cmd() // lrbp->cmd = NULL;
4 spin_unlock_irqrestore(&hwq->cq_lock, flags);
Signed-off-by: Alice Chao <alice.chao@mediatek.com>
Link: https://lore.kernel.org/r/20231024084324.12197-1-alice.chao@mediatek.com
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/ufs')
| -rw-r--r-- | drivers/ufs/core/ufshcd.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c index 5c4f2643dde6..24aa7a2de9da 100644 --- a/drivers/ufs/core/ufshcd.c +++ b/drivers/ufs/core/ufshcd.c @@ -5615,13 +5615,13 @@ static void ufshcd_mcq_compl_pending_transfer(struct ufs_hba *hba, * For those cmds of which the cqes are not present * in the cq, complete them explicitly. */ + spin_lock_irqsave(&hwq->cq_lock, flags); if (cmd && !test_bit(SCMD_STATE_COMPLETE, &cmd->state)) { - spin_lock_irqsave(&hwq->cq_lock, flags); set_host_byte(cmd, DID_REQUEUE); ufshcd_release_scsi_cmd(hba, lrbp); scsi_done(cmd); - spin_unlock_irqrestore(&hwq->cq_lock, flags); } + spin_unlock_irqrestore(&hwq->cq_lock, flags); } else { ufshcd_mcq_poll_cqe_lock(hba, hwq); } |