| Message ID | 20200206074644.1177551-1-mst@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | virtio_balloon: prevent pfn array overflow | expand |
On 06.02.20 08:47, Michael S. Tsirkin wrote: > Make sure, at build time, that pfn array is big enough to hold a single > page. It happens to be true since the PAGE_SHIFT value at the moment is > 20, which is 1M - exactly 256 4K balloon pages. > > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > --- > drivers/virtio/virtio_balloon.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c > index 8e400ece9273..2457c54b6185 100644 > --- a/drivers/virtio/virtio_balloon.c > +++ b/drivers/virtio/virtio_balloon.c > @@ -158,6 +158,8 @@ static void set_page_pfns(struct virtio_balloon *vb, > { > unsigned int i; > > + BUILD_BUG_ON(VIRTIO_BALLOON_PAGES_PER_PAGE > VIRTIO_BALLOON_ARRAY_PFNS_MAX); > + > /* > * Set balloon pfns pointing at this page. > * Note that the first pfn points at start of the page. > Reviewed-by: David Hildenbrand <david@redhat.com>
On 2020/2/6 下午3:47, Michael S. Tsirkin wrote: > Make sure, at build time, that pfn array is big enough to hold a single > page. It happens to be true since the PAGE_SHIFT value at the moment is > 20, which is 1M - exactly 256 4K balloon pages. > > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > --- > drivers/virtio/virtio_balloon.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c > index 8e400ece9273..2457c54b6185 100644 > --- a/drivers/virtio/virtio_balloon.c > +++ b/drivers/virtio/virtio_balloon.c > @@ -158,6 +158,8 @@ static void set_page_pfns(struct virtio_balloon *vb, > { > unsigned int i; > > + BUILD_BUG_ON(VIRTIO_BALLOON_PAGES_PER_PAGE > VIRTIO_BALLOON_ARRAY_PFNS_MAX); > + > /* > * Set balloon pfns pointing at this page. > * Note that the first pfn points at start of the page. Acked-by: Jason Wang <jasowang@redhat.com>
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 8e400ece9273..2457c54b6185 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -158,6 +158,8 @@ static void set_page_pfns(struct virtio_balloon *vb, { unsigned int i; + BUILD_BUG_ON(VIRTIO_BALLOON_PAGES_PER_PAGE > VIRTIO_BALLOON_ARRAY_PFNS_MAX); + /* * Set balloon pfns pointing at this page. * Note that the first pfn points at start of the page.
Make sure, at build time, that pfn array is big enough to hold a single page. It happens to be true since the PAGE_SHIFT value at the moment is 20, which is 1M - exactly 256 4K balloon pages. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> --- drivers/virtio/virtio_balloon.c | 2 ++ 1 file changed, 2 insertions(+)