From: Magnus Karlsson <magnus.karlsson@intel.com>
Date: Wed, 11 Jul 2018 10:12:52 +0200
Subject: xsk: do not return EMSGSIZE in copy mode for packets larger than MTU
Patch-mainline: v4.18-rc6
Git-commit: 09210c4bcc065d9d91ef3c051902ad18252cd3c0
References: bsc#1109837

This patch stops returning EMSGSIZE from sendmsg in copy mode when the
size of the packet is larger than the MTU. Just send it to the device
so that it will drop it as in zero-copy mode. This makes the error
reporting consistent between copy mode and zero-copy mode.

Fixes: 35fcde7f8deb ("xsk: support for Tx")
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 net/xdp/xsk.c |    7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -233,15 +233,10 @@ static int xsk_generic_xmit(struct sock
 		if (xskq_reserve_addr(xs->umem->cq))
 			goto out;
 
-		len = desc.len;
-		if (unlikely(len > xs->dev->mtu)) {
-			err = -EMSGSIZE;
-			goto out;
-		}
-
 		if (xs->queue_id >= xs->dev->real_num_tx_queues)
 			goto out;
 
+		len = desc.len;
 		skb = sock_alloc_send_skb(sk, len, 1, &err);
 		if (unlikely(!skb)) {
 			err = -EAGAIN;