releases/4.4.140/nvme-pci-initialize-queue-memory-before-interrupts.patch

   1 From 161b8be2bd6abad250d4b3f674bdd5480f15beeb Mon Sep 17 00:00:00 2001
   2 From: Keith Busch <keith.busch@intel.com>
   3 Date: Thu, 14 Sep 2017 13:54:39 -0400
   4 Subject: nvme-pci: initialize queue memory before interrupts
   5
   6 From: Keith Busch <keith.busch@intel.com>
   7
   8 commit 161b8be2bd6abad250d4b3f674bdd5480f15beeb upstream.
   9
  10 A spurious interrupt before the nvme driver has initialized the completion
  11 queue may inadvertently cause the driver to believe it has a completion
  12 to process. This may result in a NULL dereference since the nvmeq's tags
  13 are not set at this point.
  14
  15 The patch initializes the host's CQ memory so that a spurious interrupt
  16 isn't mistaken for a real completion.
  17
  18 Signed-off-by: Keith Busch <keith.busch@intel.com>
  19 Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
  20 Signed-off-by: Christoph Hellwig <hch@lst.de>
  21 Signed-off-by: Jens Axboe <axboe@kernel.dk>
  22 [bwh: Backported to 4.4: adjust context]
  23 Cc: Ben Hutchings <ben.hutchings@codethink.co.uk>
  24 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  25 ---
  26  drivers/nvme/host/pci.c |    4 ++--
  27  1 file changed, 2 insertions(+), 2 deletions(-)
  28
  29 --- a/drivers/nvme/host/pci.c
  30 +++ b/drivers/nvme/host/pci.c
  31 @@ -1589,11 +1589,11 @@ static int nvme_create_queue(struct nvme
  32         if (result < 0)
  33                 goto release_cq;
  34
  35 +       nvme_init_queue(nvmeq, qid);
  36         result = queue_request_irq(dev, nvmeq, nvmeq->irqname);
  37         if (result < 0)
  38                 goto release_sq;
  39
  40 -       nvme_init_queue(nvmeq, qid);
  41         return result;
  42
  43   release_sq:
  44 @@ -1797,6 +1797,7 @@ static int nvme_configure_admin_queue(st
  45                 goto free_nvmeq;
  46
  47         nvmeq->cq_vector = 0;
  48 +       nvme_init_queue(nvmeq, 0);
  49         result = queue_request_irq(dev, nvmeq, nvmeq->irqname);
  50         if (result) {
  51                 nvmeq->cq_vector = -1;
  52 @@ -3165,7 +3166,6 @@ static void nvme_probe_work(struct work_
  53                 goto disable;
  54         }
  55
  56 -       nvme_init_queue(dev->queues[0], 0);
  57         result = nvme_alloc_admin_tags(dev);
  58         if (result)
  59                 goto disable;