macvtap: zerocopy: set SKBTX_DEV_ZEROCOPY only when skb is built successfully (01d6657b) · Commits · 戴 / test

Current the SKBTX_DEV_ZEROCOPY is set unconditionally after zerocopy_sg_from_iovec(), this would lead NULL pointer when macvtap fails to build zerocopy skb because destructor_arg was not initialized. Solve this by set this flag after the skb were built successfully. Signed-off-by:

Jason Wang <jasowang@redhat.com> Signed-off-by:

Michael S. Tsirkin <mst@redhat.com>

drivers/net/macvtap.c

+5 −4

Original line number	Diff line number	Diff line
		@@ -699,10 +699,9 @@ static ssize_t macvtap_get_user(struct macvtap_queue q, struct msghdr m,
		if (!skb)
		goto err;

		if (zerocopy) {
		if (zerocopy)
		err = zerocopy_sg_from_iovec(skb, iv, vnet_hdr_len, count);
		skb_shinfo(skb)->tx_flags \|= SKBTX_DEV_ZEROCOPY;
		} else
		else
		err = skb_copy_datagram_from_iovec(skb, 0, iv, vnet_hdr_len,
		len);
		if (err)
		@@ -721,8 +720,10 @@ static ssize_t macvtap_get_user(struct macvtap_queue q, struct msghdr m,
		rcu_read_lock_bh();
		vlan = rcu_dereference_bh(q->vlan);
		/* copy skb_ubuf_info for callback when skb has no error */
		if (zerocopy)
		if (zerocopy) {
		skb_shinfo(skb)->destructor_arg = m->msg_control;
		skb_shinfo(skb)->tx_flags \|= SKBTX_DEV_ZEROCOPY;
		}
		if (vlan)
		macvlan_start_xmit(skb, vlan->dev);
		else

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