[PATH v2] NVMe: init nvme queue before enabling irq

[Wenbo Wang]

From: Wenbo Wang <wenbo.wang@xxxxxxxxxxxx>

During reset process, the nvme_dev->bar (ioremapped) may change,
so nvmeq->q_db shall be also updated by nvme_init_queue().

Currently nvmeq irq is enabled before queue init, so a spurious
interrupt triggered nvme_process_cq may access nvmeq->q_db just
before it is updated, this could cause kernel panic.

Signed-off-by: Wenbo Wang <wenbo.wang@xxxxxxxxxxxx>
Reviewed-by: Wenwei Tao <wenwei.tao@xxxxxxxxxxxx>
---
 drivers/nvme/host/pci.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index f5c0e26..3371c18 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1529,9 +1529,6 @@ static struct nvme_queue *nvme_alloc_queue(struct nvme_dev *dev, int qid,
 	snprintf(nvmeq->irqname, sizeof(nvmeq->irqname), "nvme%dq%d",
 			dev->instance, qid);
 	spin_lock_init(&nvmeq->q_lock);
-	nvmeq->cq_head = 0;
-	nvmeq->cq_phase = 1;
-	nvmeq->q_db = &dev->dbs[qid * 2 * dev->db_stride];
 	nvmeq->q_depth = depth;
 	nvmeq->qid = qid;
 	nvmeq->cq_vector = -1;
@@ -1590,11 +1587,17 @@ static int nvme_create_queue(struct nvme_queue *nvmeq, int qid)
 	if (result < 0)
 		goto release_cq;
 
+	/*
+	 * Init queue door bell ioremap address before enabling irq, if not,
+	 * a spurious interrupt triggered nvme_process_cq may access invalid
+	 * address
+	 */
+	nvme_init_queue(nvmeq, qid);
+
 	result = queue_request_irq(dev, nvmeq, nvmeq->irqname);
 	if (result < 0)
 		goto release_sq;
 
-	nvme_init_queue(nvmeq, qid);
 	return result;
 
  release_sq:
@@ -1789,6 +1792,8 @@ static int nvme_configure_admin_queue(struct nvme_dev *dev)
 	if (result)
 		goto free_nvmeq;
 
+	nvme_init_queue(nvmeq, 0);
+
 	nvmeq->cq_vector = 0;
 	result = queue_request_irq(dev, nvmeq, nvmeq->irqname);
 	if (result) {
@@ -3164,7 +3169,6 @@ static void nvme_probe_work(struct work_struct *work)
 		goto disable;
 	}
 
-	nvme_init_queue(dev->queues[0], 0);
 	result = nvme_alloc_admin_tags(dev);
 	if (result)
 		goto disable;
-- 
1.8.3.1