diff options
Diffstat (limited to 'drivers/virtio/virtio_ring.c')
| -rw-r--r-- | drivers/virtio/virtio_ring.c | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 6d2614e34470..00f64f2f8b72 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -14,6 +14,9 @@ #include <linux/spinlock.h> #include <xen/xen.h> +static bool force_used_validation = false; +module_param(force_used_validation, bool, 0444); + #ifdef DEBUG /* For development, we want to crash whenever the ring is screwed. */ #define BAD_RING(_vq, fmt, args...) \ @@ -182,6 +185,9 @@ struct vring_virtqueue { } packed; }; + /* Per-descriptor in buffer length */ + u32 *buflen; + /* How to notify other side. FIXME: commonalize hcalls! */ bool (*notify)(struct virtqueue *vq); @@ -490,6 +496,7 @@ static inline int virtqueue_add_split(struct virtqueue *_vq, unsigned int i, n, avail, descs_used, prev, err_idx; int head; bool indirect; + u32 buflen = 0; START_USE(vq); @@ -571,6 +578,7 @@ static inline int virtqueue_add_split(struct virtqueue *_vq, VRING_DESC_F_NEXT | VRING_DESC_F_WRITE, indirect); + buflen += sg->length; } } /* Last one doesn't continue. */ @@ -610,6 +618,10 @@ static inline int virtqueue_add_split(struct virtqueue *_vq, else vq->split.desc_state[head].indir_desc = ctx; + /* Store in buffer length if necessary */ + if (vq->buflen) + vq->buflen[head] = buflen; + /* Put entry in available array (but don't update avail->idx until they * do sync). */ avail = vq->split.avail_idx_shadow & (vq->split.vring.num - 1); @@ -784,6 +796,11 @@ static void *virtqueue_get_buf_ctx_split(struct virtqueue *_vq, BAD_RING(vq, "id %u is not a head!\n", i); return NULL; } + if (vq->buflen && unlikely(*len > vq->buflen[i])) { + BAD_RING(vq, "used len %d is larger than in buflen %u\n", + *len, vq->buflen[i]); + return NULL; + } /* detach_buf_split clears data, so grab it now. */ ret = vq->split.desc_state[i].data; @@ -1062,6 +1079,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, unsigned int i, n, err_idx; u16 head, id; dma_addr_t addr; + u32 buflen = 0; head = vq->packed.next_avail_idx; desc = alloc_indirect_packed(total_sg, gfp); @@ -1091,6 +1109,8 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, desc[i].addr = cpu_to_le64(addr); desc[i].len = cpu_to_le32(sg->length); i++; + if (n >= out_sgs) + buflen += sg->length; } } @@ -1144,6 +1164,10 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, vq->packed.desc_state[id].indir_desc = desc; vq->packed.desc_state[id].last = id; + /* Store in buffer length if necessary */ + if (vq->buflen) + vq->buflen[id] = buflen; + vq->num_added += 1; pr_debug("Added buffer head %i to %p\n", head, vq); @@ -1179,6 +1203,7 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq, __le16 head_flags, flags; u16 head, id, prev, curr, avail_used_flags; int err; + u32 buflen = 0; START_USE(vq); @@ -1258,6 +1283,8 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq, 1 << VRING_PACKED_DESC_F_AVAIL | 1 << VRING_PACKED_DESC_F_USED; } + if (n >= out_sgs) + buflen += sg->length; } } @@ -1277,6 +1304,10 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq, vq->packed.desc_state[id].indir_desc = ctx; vq->packed.desc_state[id].last = prev; + /* Store in buffer length if necessary */ + if (vq->buflen) + vq->buflen[id] = buflen; + /* * A driver MUST NOT make the first descriptor in the list * available before all subsequent descriptors comprising @@ -1463,6 +1494,11 @@ static void *virtqueue_get_buf_ctx_packed(struct virtqueue *_vq, BAD_RING(vq, "id %u is not a head!\n", id); return NULL; } + if (vq->buflen && unlikely(*len > vq->buflen[id])) { + BAD_RING(vq, "used len %d is larger than in buflen %u\n", + *len, vq->buflen[id]); + return NULL; + } /* detach_buf_packed clears data, so grab it now. */ ret = vq->packed.desc_state[id].data; @@ -1668,6 +1704,7 @@ static struct virtqueue *vring_create_virtqueue_packed( struct vring_virtqueue *vq; struct vring_packed_desc *ring; struct vring_packed_desc_event *driver, *device; + struct virtio_driver *drv = drv_to_virtio(vdev->dev.driver); dma_addr_t ring_dma_addr, driver_event_dma_addr, device_event_dma_addr; size_t ring_size_in_bytes, event_size_in_bytes; @@ -1757,6 +1794,15 @@ static struct virtqueue *vring_create_virtqueue_packed( if (!vq->packed.desc_extra) goto err_desc_extra; + if (!drv->suppress_used_validation || force_used_validation) { + vq->buflen = kmalloc_array(num, sizeof(*vq->buflen), + GFP_KERNEL); + if (!vq->buflen) + goto err_buflen; + } else { + vq->buflen = NULL; + } + /* No callback? Tell other side not to bother us. */ if (!callback) { vq->packed.event_flags_shadow = VRING_PACKED_EVENT_FLAG_DISABLE; @@ -1769,6 +1815,8 @@ static struct virtqueue *vring_create_virtqueue_packed( spin_unlock(&vdev->vqs_list_lock); return &vq->vq; +err_buflen: + kfree(vq->packed.desc_extra); err_desc_extra: kfree(vq->packed.desc_state); err_desc_state: @@ -2176,6 +2224,7 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index, void (*callback)(struct virtqueue *), const char *name) { + struct virtio_driver *drv = drv_to_virtio(vdev->dev.driver); struct vring_virtqueue *vq; if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED)) @@ -2235,6 +2284,15 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index, if (!vq->split.desc_extra) goto err_extra; + if (!drv->suppress_used_validation || force_used_validation) { + vq->buflen = kmalloc_array(vring.num, sizeof(*vq->buflen), + GFP_KERNEL); + if (!vq->buflen) + goto err_buflen; + } else { + vq->buflen = NULL; + } + /* Put everything in free lists. */ vq->free_head = 0; memset(vq->split.desc_state, 0, vring.num * @@ -2245,6 +2303,8 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index, spin_unlock(&vdev->vqs_list_lock); return &vq->vq; +err_buflen: + kfree(vq->split.desc_extra); err_extra: kfree(vq->split.desc_state); err_state: |