Commit 97ef7b4c authored Dec 08, 2018 by Willem de Bruijn Committed by David S. Miller Dec 08, 2018

ip: silence udp zerocopy smatch false positive



extra_uref is used in __ip(6)_append_data only if uarg is set.

Smatch sees that the variable is passed to sock_zerocopy_put_abort.
This function accesses it only when uarg is set, but smatch cannot
infer this.

Make this dependency explicit.

Fixes: 52900d22 ("udp: elide zerocopy operation in hot path")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 83af01ba

net/ipv4/ip_output.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -1130,6 +1130,7 @@ alloc_new_skb:
		error_efault:
		err = -EFAULT;
		error:
		if (uarg)
		sock_zerocopy_put_abort(uarg, extra_uref);
		cork->length -= length;
		IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTDISCARDS);

net/ipv6/ip6_output.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -1575,6 +1575,7 @@ alloc_new_skb:
		error_efault:
		err = -EFAULT;
		error:
		if (uarg)
		sock_zerocopy_put_abort(uarg, extra_uref);
		cork->length -= length;
		IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);

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