VQs may be accessed to mark the device broken while they are
created/destroyed. Hence protect the access to the vqs list.
Fixes: e2dcdfe95c0b ("virtio: virtio_break_device() to mark all virtqueues
broken.")
Signed-off-by: Parav Pandit <[email protected]>
---
drivers/virtio/virtio.c | 1 +
drivers/virtio/virtio_ring.c | 8 ++++++++
include/linux/virtio.h | 1 +
3 files changed, 10 insertions(+)
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index 4b15c00c0a0a..a0d81e35ec4b 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -355,6 +355,7 @@ int register_virtio_device(struct virtio_device *dev)
virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
INIT_LIST_HEAD(&dev->vqs);
+ rwlock_init(&dev->vqs_list_lock);
/*
* device_add() causes the bus infrastructure to look for a matching
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index d2e1a7a21171..66a91dec39d9 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -1755,7 +1755,9 @@ static struct virtqueue *vring_create_virtqueue_packed(
cpu_to_le16(vq->packed.event_flags_shadow);
}
+ write_lock(&vdev->vqs_list_lock);
list_add_tail(&vq->vq.list, &vdev->vqs);
+ write_unlock(&vdev->vqs_list_lock);
return &vq->vq;
err_desc_extra:
@@ -2229,7 +2231,9 @@ struct virtqueue *__vring_new_virtqueue(unsigned int
index,
memset(vq->split.desc_state, 0, vring.num *
sizeof(struct vring_desc_state_split));
+ write_lock(&vdev->vqs_list_lock);
list_add_tail(&vq->vq.list, &vdev->vqs);
+ write_unlock(&vdev->vqs_list_lock);
return &vq->vq;
err_extra:
@@ -2291,7 +2295,9 @@ void vring_del_virtqueue(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
+ write_lock(&vq->vq.vdev->vqs_list_lock);
list_del(&_vq->list);
+ write_unlock(&vq->vq.vdev->vqs_list_lock);
if (vq->we_own_ring) {
if (vq->packed_ring) {
@@ -2386,12 +2392,14 @@ void virtio_break_device(struct virtio_device *dev)
{
struct virtqueue *_vq;
+ read_lock(&dev->vqs_list_lock);
list_for_each_entry(_vq, &dev->vqs, list) {
struct vring_virtqueue *vq = to_vvq(_vq);
/* Pairs with READ_ONCE() in virtqueue_is_broken(). */
smp_store_release(&vq->broken, true);
}
+ read_unlock(&dev->vqs_list_lock);
}
EXPORT_SYMBOL_GPL(virtio_break_device);
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index b1894e0323fa..1cf77d480ef3 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -115,6 +115,7 @@ struct virtio_device {
const struct virtio_config_ops *config;
const struct vringh_config_ops *vringh_config;
struct list_head vqs;
+ rwlock_t vqs_list_lock;
u64 features;
void *priv;
};
--
2.27.0
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