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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Zhangguanghui <zhang.guanghui@h3c.com>,
        Dick Kennedy <dick.kennedy@broadcom.com>,
        James Smart <jsmart2021@gmail.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.4 019/191] scsi: lpfc: Fix hardlockup in lpfc_abort_handler
Date:   Thu,  2 Jan 2020 23:05:01 +0100
Message-Id: <20200102215831.933817549@linuxfoundation.org>
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References: <20200102215829.911231638@linuxfoundation.org>
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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 ad8ef67a1db3..aa82d538a18a 100644
--- a/drivers/scsi/lpfc/lpfc_scsi.c
+++ b/drivers/scsi/lpfc/lpfc_scsi.c
@@ -4846,20 +4846,21 @@ 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