1 files changed, 27 insertions, 15 deletions

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 3a5f81a66d34..9f7942cbcbb2 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -295,11 +295,8 @@ static void vhost_vq_meta_reset(struct vhost_dev *d)
 {
 	int i;
 
-	for (i = 0; i < d->nvqs; ++i) {
-		mutex_lock(&d->vqs[i]->mutex);
+	for (i = 0; i < d->nvqs; ++i)
 		__vhost_vq_meta_reset(d->vqs[i]);
-		mutex_unlock(&d->vqs[i]->mutex);
-	}
 }
 
 static void vhost_vq_reset(struct vhost_dev *dev,
@@ -658,7 +655,7 @@ static bool log_access_ok(void __user *log_base, u64 addr, unsigned long sz)
 	    a + (unsigned long)log_base > ULONG_MAX)
 		return false;
 
-	return access_ok(VERIFY_WRITE, log_base + a,
+	return access_ok(log_base + a,
 			 (sz + VHOST_PAGE_SIZE * 8 - 1) / VHOST_PAGE_SIZE / 8);
 }
 
@@ -684,7 +681,7 @@ static bool vq_memory_access_ok(void __user *log_base, struct vhost_umem *umem,
 			return false;
 
 
-		if (!access_ok(VERIFY_WRITE, (void __user *)a,
+		if (!access_ok((void __user *)a,
 				    node->size))
 			return false;
 		else if (log_all && !log_access_ok(log_base,
@@ -895,6 +892,20 @@ static inline void __user *__vhost_get_user(struct vhost_virtqueue *vq,
 #define vhost_get_used(vq, x, ptr) \
 	vhost_get_user(vq, x, ptr, VHOST_ADDR_USED)
 
+static void vhost_dev_lock_vqs(struct vhost_dev *d)
+{
+	int i = 0;
+	for (i = 0; i < d->nvqs; ++i)
+		mutex_lock_nested(&d->vqs[i]->mutex, i);
+}
+
+static void vhost_dev_unlock_vqs(struct vhost_dev *d)
+{
+	int i = 0;
+	for (i = 0; i < d->nvqs; ++i)
+		mutex_unlock(&d->vqs[i]->mutex);
+}
+
 static int vhost_new_umem_range(struct vhost_umem *umem,
 				u64 start, u64 size, u64 end,
 				u64 userspace_addr, int perm)
@@ -944,10 +955,7 @@ static void vhost_iotlb_notify_vq(struct vhost_dev *d,
 		if (msg->iova <= vq_msg->iova &&
 		    msg->iova + msg->size - 1 >= vq_msg->iova &&
 		    vq_msg->type == VHOST_IOTLB_MISS) {
-			mutex_lock(&node->vq->mutex);
 			vhost_poll_queue(&node->vq->poll);
-			mutex_unlock(&node->vq->mutex);
-
 			list_del(&node->node);
 			kfree(node);
 		}
@@ -965,10 +973,10 @@ static bool umem_access_ok(u64 uaddr, u64 size, int access)
 		return false;
 
 	if ((access & VHOST_ACCESS_RO) &&
-	    !access_ok(VERIFY_READ, (void __user *)a, size))
+	    !access_ok((void __user *)a, size))
 		return false;
 	if ((access & VHOST_ACCESS_WO) &&
-	    !access_ok(VERIFY_WRITE, (void __user *)a, size))
+	    !access_ok((void __user *)a, size))
 		return false;
 	return true;
 }
@@ -979,6 +987,7 @@ static int vhost_process_iotlb_msg(struct vhost_dev *dev,
 	int ret = 0;
 
 	mutex_lock(&dev->mutex);
+	vhost_dev_lock_vqs(dev);
 	switch (msg->type) {
 	case VHOST_IOTLB_UPDATE:
 		if (!dev->iotlb) {
@@ -1012,6 +1021,7 @@ static int vhost_process_iotlb_msg(struct vhost_dev *dev,
 		break;
 	}
 
+	vhost_dev_unlock_vqs(dev);
 	mutex_unlock(&dev->mutex);
 
 	return ret;
@@ -1175,10 +1185,10 @@ static bool vq_access_ok(struct vhost_virtqueue *vq, unsigned int num,
 {
 	size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
 
-	return access_ok(VERIFY_READ, desc, num * sizeof *desc) &&
-	       access_ok(VERIFY_READ, avail,
+	return access_ok(desc, num * sizeof *desc) &&
+	       access_ok(avail,
 			 sizeof *avail + num * sizeof *avail->ring + s) &&
-	       access_ok(VERIFY_WRITE, used,
+	       access_ok(used,
 			sizeof *used + num * sizeof *used->ring + s);
 }
 
@@ -1804,7 +1814,7 @@ int vhost_vq_init_access(struct vhost_virtqueue *vq)
 		goto err;
 	vq->signalled_used_valid = false;
 	if (!vq->iotlb &&
-	    !access_ok(VERIFY_READ, &vq->used->idx, sizeof vq->used->idx)) {
+	    !access_ok(&vq->used->idx, sizeof vq->used->idx)) {
 		r = -EFAULT;
 		goto err;
 	}
@@ -2223,6 +2233,8 @@ int vhost_add_used_n(struct vhost_virtqueue *vq, struct vring_used_elem *heads,
 		return -EFAULT;
 	}
 	if (unlikely(vq->log_used)) {
+		/* Make sure used idx is seen before log. */
+		smp_wmb();
 		/* Log used index update. */
 		log_write(vq->log_base,
 			  vq->log_addr + offsetof(struct vring_used, idx),