[PATCH 4.19 45/63] tcp: remove redundant check on tskb

Greg Kroah-Hartman
2024-05-14T11:41:00Z

From: Colin Ian King <colin.king@canonical.com>

[ Upstream commit d1edc085559744fbda7a55e97eeae8bd6135a11b ]

The non-null check on tskb is always false because it is in an else
path of a check on tskb and hence tskb is null in this code block.
This is check is therefore redundant and can be removed as well
as the label coalesc.

if (tsbk) {
...
} else {
...
if (unlikely(!skb)) {
if (tskb) /* can never be true, redundant code */
goto coalesc;
return;
}
}

Addresses-Coverity: ("Logically dead code")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 94062790aedb ("tcp: defer shutdown(SEND_SHUTDOWN) for TCP_SYN_RECV sockets")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/ipv4/tcp_output.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 670804d4c1690..8b78cb96a8461 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -3132,7 +3132,6 @@ void tcp_send_fin(struct sock *sk)
tskb = skb_rb_last(&sk->tcp_rtx_queue);

if (tskb) {
-coalesce:
TCP_SKB_CB(tskb)->tcp_flags |= TCPHDR_FIN;
TCP_SKB_CB(tskb)->end_seq++;
tp->write_seq++;
@@ -3148,11 +3147,9 @@ void tcp_send_fin(struct sock *sk)
}
} else {
skb = alloc_skb_fclone(MAX_TCP_HEADER, sk->sk_allocation);
- if (unlikely(!skb)) {
- if (tskb)
- goto coalesce;
+ if (unlikely(!skb))
return;
- }
+
INIT_LIST_HEAD(&skb->tcp_tsorted_anchor);
skb_reserve(skb, MAX_TCP_HEADER);
sk_forced_mem_schedule(sk, skb->truesize);
--
2.43.0