[PATCH AUTOSEL 5.4 018/134] scsi: lpfc: Fix hardlockup in lpfc_abort_handler

Sasha Levin
2019-12-11T16:09:05Z

From: James Smart <jsmart2021@gmail.com>

[ Upstream commit 91a52b617cdb8bf6d298892101c061d438b84a19 ]

In lpfc_abort_handler, the lock acquire order is hbalock (irqsave),
buf_lock (irq) and ring_lock (irq). The issue is that in two places the
locks are released out of order - the buf_lock and the hbalock - resulting
in the cpu preemption/lock flags getting restored out of order and
deadlocking the cpu.

Fix the unlock order by fully releasing the hbalocks as well.

CC: Zhangguanghui <zhang.guanghui@h3c.com>
Link: https://lore.kernel.org/r/20191018211832.7917-7-jsmart2021@gmail.com
Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/scsi/lpfc/lpfc_scsi.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/lpfc/lpfc_scsi.c b/drivers/scsi/lpfc/lpfc_scsi.c
index 6822cd9ff8f1e..68b31b27fa057 100644
--- a/drivers/scsi/lpfc/lpfc_scsi.c
+++ b/drivers/scsi/lpfc/lpfc_scsi.c
@@ -4843,20 +4843,21 @@ lpfc_abort_handler(struct scsi_cmnd *cmnd)
ret_val = __lpfc_sli_issue_iocb(phba, LPFC_FCP_RING,
abtsiocb, 0);
}
- /* no longer need the lock after this point */
- spin_unlock_irqrestore(&phba->hbalock, flags);

if (ret_val == IOCB_ERROR) {
/* Indicate the IO is not being aborted by the driver. */
iocb->iocb_flag &= ~LPFC_DRIVER_ABORTED;
lpfc_cmd->waitq = NULL;
spin_unlock(&lpfc_cmd->buf_lock);
+ spin_unlock_irqrestore(&phba->hbalock, flags);
lpfc_sli_release_iocbq(phba, abtsiocb);
ret = FAILED;
goto out;
}

+ /* no longer need the lock after this point */
spin_unlock(&lpfc_cmd->buf_lock);
+ spin_unlock_irqrestore(&phba->hbalock, flags);

if (phba->cfg_poll & DISABLE_FCP_RING_INT)
lpfc_sli_handle_fast_ring_event(phba,
--
2.20.1