diff options
| author | Brian Foley <brian.foley@arm.com> | 2012-09-24 17:33:41 +0400 |
|---|---|---|
| committer | Rusty Russell <rusty@rustcorp.com.au> | 2012-09-28 09:35:16 +0400 |
| commit | 3850d29fc40f3494a3e9c3aac45b6afe53526449 (patch) | |
| tree | b80c5c7819de0bfc2a75a55939568f3784ed5dbf | |
| parent | 74a74b376c997645b32a4fdf8e76705a00ae097a (diff) | |
| download | linux-3850d29fc40f3494a3e9c3aac45b6afe53526449.tar.xz | |
virtio_mmio: fix off by one error allocating queue
vm_setup_vq fails to allow VirtQueues needing only 2 pages of
storage, as it should. Found with a kernel using 64kB pages, but
can be provoked if a virtio device reports QueueNumMax where the
descriptor table and available ring fit in one page, and the used
ring on the second (<= 227 descriptors with 4kB pages and <= 3640
with 64kB pages.)
Signed-off-by: Brian Foley <brian.foley@arm.com>
Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| -rw-r--r-- | drivers/virtio/virtio_mmio.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c index 5d7fee385b70..09edeecd42a5 100644 --- a/drivers/virtio/virtio_mmio.c +++ b/drivers/virtio/virtio_mmio.c @@ -334,8 +334,8 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index, while (1) { size = PAGE_ALIGN(vring_size(info->num, VIRTIO_MMIO_VRING_ALIGN)); - /* Already smallest possible allocation? */ - if (size <= VIRTIO_MMIO_VRING_ALIGN * 2) { + /* Did the last iter shrink the queue below minimum size? */ + if (size < VIRTIO_MMIO_VRING_ALIGN * 2) { err = -ENOMEM; goto error_alloc_pages; } |