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| author | Halil Pasic <pasic@linux.ibm.com> | 2019-07-23 17:11:01 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-09-16 08:22:23 +0200 |
| commit | b1dd1d06b31da3cb8a535f9eeb3909e83f9ba3f5 (patch) | |
| tree | aa8a3c52b7266e7690ed102c2c4dfe416d503614 | |
| parent | 057cdb6f0f47c643905df5557fdf9d56f46d2931 (diff) | |
| download | linux-stable-b1dd1d06b31da3cb8a535f9eeb3909e83f9ba3f5.tar.gz linux-stable-b1dd1d06b31da3cb8a535f9eeb3909e83f9ba3f5.tar.bz2 linux-stable-b1dd1d06b31da3cb8a535f9eeb3909e83f9ba3f5.zip | |
virtio/s390: fix race on airq_areas[]
[ Upstream commit 4f419eb14272e0698e8c55bb5f3f266cc2a21c81 ]
The access to airq_areas was racy ever since the adapter interrupts got
introduced to virtio-ccw, but since commit 39c7dcb15892 ("virtio/s390:
make airq summary indicators DMA") this became an issue in practice as
well. Namely before that commit the airq_info that got overwritten was
still functional. After that commit however the two infos share a
summary_indicator, which aggravates the situation. Which means
auto-online mechanism occasionally hangs the boot with virtio_blk.
Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 96b14536d935 ("virtio-ccw: virtio-ccw adapter interrupt support.")
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/s390/virtio/virtio_ccw.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c index ec54538f7ae1..67efdf25657f 100644 --- a/drivers/s390/virtio/virtio_ccw.c +++ b/drivers/s390/virtio/virtio_ccw.c @@ -132,6 +132,7 @@ struct airq_info { struct airq_iv *aiv; }; static struct airq_info *airq_areas[MAX_AIRQ_AREAS]; +static DEFINE_MUTEX(airq_areas_lock); #define CCW_CMD_SET_VQ 0x13 #define CCW_CMD_VDEV_RESET 0x33 @@ -244,9 +245,11 @@ static unsigned long get_airq_indicator(struct virtqueue *vqs[], int nvqs, unsigned long bit, flags; for (i = 0; i < MAX_AIRQ_AREAS && !indicator_addr; i++) { + mutex_lock(&airq_areas_lock); if (!airq_areas[i]) airq_areas[i] = new_airq_info(); info = airq_areas[i]; + mutex_unlock(&airq_areas_lock); if (!info) return 0; write_lock_irqsave(&info->lock, flags); |