Commit ade4e7de authored by Eric Dumazet's avatar Eric Dumazet Committed by Lipeng Sang
Browse files

tcp: minor optimization in tcp_add_backlog() 

stable inclusion
from stable-v5.10.153
commit 49713d7c38588311815889cb8c766591255ec836
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I64YCA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=49713d7c38588311815889cb8c766591255ec836



--------------------------------

[ Upstream commit d519f350 ]

If packet is going to be coalesced, sk_sndbuf/sk_rcvbuf values
are not used. Defer their access to the point we need them.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Stable-dep-of: ec791d81 ("tcp: fix a signed-integer-overflow bug in tcp_add_backlog()")
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
Signed-off-by: default avatarLipeng Sang <sanglipeng1@jd.com>
parent 4ce2bd3d

net/ipv4/tcp_ipv4.c

+2 −3
Original line number Diff line number Diff line
@@ -1770,8 +1770,7 @@ int tcp_v4_early_demux(struct sk_buff *skb) 


bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb)

{

	u32 limit = READ_ONCE(sk->sk_rcvbuf) + READ_ONCE(sk->sk_sndbuf);

	u32 tail_gso_size, tail_gso_segs;

	u32 limit, tail_gso_size, tail_gso_segs;

	struct skb_shared_info *shinfo;

	const struct tcphdr *th;

	struct tcphdr *thtail;
@@ -1878,7 +1877,7 @@ bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb) 
	 * to reduce memory overhead, so add a little headroom here.

	 * Few sockets backlog are possibly concurrently non empty.

	 */

	limit += 64*1024;

	limit = READ_ONCE(sk->sk_rcvbuf) + READ_ONCE(sk->sk_sndbuf) + 64*1024;



	if (unlikely(sk_add_backlog(sk, skb, limit))) {

		bh_unlock_sock(sk);