Re: [PATCH net v3 1/2] net: core: propagate unreadable flag in skb_zerocopy
Ilya Maximets <[email protected]>
| Newsgroups | org.kernel.vger.netdev,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <[email protected]> |
On 8/11/26 9:53 PM, Mina Almasry wrote:
> diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
> index ae69b2cabab9e..482893a5f67dc 100644
> --- a/net/openvswitch/datapath.c
> +++ b/net/openvswitch/datapath.c
> @@ -467,6 +467,9 @@ static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb,
> if (!dp_ifindex)
> return -ENODEV;
>
> + if (!skb_frags_readable(skb))
> + return -EFAULT;
> +
> if (skb_vlan_tag_present(skb)) {
> nskb = skb_clone(skb, GFP_ATOMIC);
> if (!nskb)
FWIW, the devmem integration doesn't seem well-designed. I understand
that it is for performance, but IMO there should be a way to copy the
data on a slow path to avoid dropping the packets. Clamping without
notifying the users that the packet is truncated is not a good solution.
Not for OVS, not for other parts of the kernel networking stack. It's
a uAPI breakage.
As it is, there is not much we can do here without extensive changes
in userspace applications, so for this OVS block:
Reviewed-by: Ilya Maximets <[email protected]>