diff options
| author | Seth Forshee <seth.forshee@canonical.com> | 2014-11-25 20:28:24 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-12-16 09:09:42 -0800 |
| commit | 0a8c00c7edd66707bc60fb0dee21bdb2740baf4e (patch) | |
| tree | cdda58ec3f75cf9e5e56da50bf598ebbf9bc5dbf | |
| parent | 4542246879ccdb5f3cc58d8e66955246a74a9494 (diff) | |
| download | lwn-0a8c00c7edd66707bc60fb0dee21bdb2740baf4e.tar.gz lwn-0a8c00c7edd66707bc60fb0dee21bdb2740baf4e.zip | |
xen-netfront: Remove BUGs on paged skb data which crosses a page boundary
commit 8d609725d4357f499e2103e46011308b32f53513 upstream.
These BUGs can be erroneously triggered by frags which refer to
tail pages within a compound page. The data in these pages may
overrun the hardware page while still being contained within the
compound page, but since compound_order() evaluates to 0 for tail
pages the assertion fails. The code already iterates through
subsequent pages correctly in this scenario, so the BUGs are
unnecessary and can be removed.
Fixes: f36c374782e4 ("xen/netfront: handle compound page fragments on transmit")
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/net/xen-netfront.c | 5 |
1 files changed, 0 insertions, 5 deletions
diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index 82e0f1fd2254..a1db958df4a4 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -459,9 +459,6 @@ static void xennet_make_frags(struct sk_buff *skb, struct net_device *dev, len = skb_frag_size(frag); offset = frag->page_offset; - /* Data must not cross a page boundary. */ - BUG_ON(len + offset > PAGE_SIZE<<compound_order(page)); - /* Skip unused frames from start of page */ page += offset >> PAGE_SHIFT; offset &= ~PAGE_MASK; @@ -469,8 +466,6 @@ static void xennet_make_frags(struct sk_buff *skb, struct net_device *dev, while (len > 0) { unsigned long bytes; - BUG_ON(offset >= PAGE_SIZE); - bytes = PAGE_SIZE - offset; if (bytes > len) bytes = len; |