From a81722ddd7e4d76c9bbff078d29416e18c6d7f71 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 4 Aug 2023 14:46:15 +0000 Subject: [PATCH] tcp: set TCP_LINGER2 locklessly tp->linger2 can be set locklessly as long as readers use READ_ONCE(). Signed-off-by: Eric Dumazet Acked-by: Soheil Hassas Yeganeh Signed-off-by: David S. Miller --- net/ipv4/tcp.c | 19 +++++++++---------- net/ipv4/tcp_input.c | 2 +- net/ipv4/tcp_timer.c | 2 +- 3 files changed, 11 insertions(+), 12 deletions(-) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index e74a959..5c71b4f 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2865,7 +2865,7 @@ adjudge_to_death: if (sk->sk_state == TCP_FIN_WAIT2) { struct tcp_sock *tp = tcp_sk(sk); - if (tp->linger2 < 0) { + if (READ_ONCE(tp->linger2) < 0) { tcp_set_state(sk, TCP_CLOSE); tcp_send_active_reset(sk, GFP_ATOMIC); __NET_INC_STATS(sock_net(sk), @@ -3471,6 +3471,14 @@ int do_tcp_setsockopt(struct sock *sk, int level, int optname, return tcp_sock_set_keepintvl(sk, val); case TCP_KEEPCNT: return tcp_sock_set_keepcnt(sk, val); + case TCP_LINGER2: + if (val < 0) + WRITE_ONCE(tp->linger2, -1); + else if (val > TCP_FIN_TIMEOUT_MAX / HZ) + WRITE_ONCE(tp->linger2, TCP_FIN_TIMEOUT_MAX); + else + WRITE_ONCE(tp->linger2, val * HZ); + return 0; } sockopt_lock_sock(sk); @@ -3576,15 +3584,6 @@ int do_tcp_setsockopt(struct sock *sk, int level, int optname, tp->save_syn = val; break; - case TCP_LINGER2: - if (val < 0) - WRITE_ONCE(tp->linger2, -1); - else if (val > TCP_FIN_TIMEOUT_MAX / HZ) - WRITE_ONCE(tp->linger2, TCP_FIN_TIMEOUT_MAX); - else - WRITE_ONCE(tp->linger2, val * HZ); - break; - case TCP_DEFER_ACCEPT: /* Translate value in seconds to number of retransmits */ WRITE_ONCE(icsk->icsk_accept_queue.rskq_defer_accept, diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 2995802..deac708 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -6624,7 +6624,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb) break; } - if (tp->linger2 < 0) { + if (READ_ONCE(tp->linger2) < 0) { tcp_done(sk); NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONDATA); return 1; diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c index f99e2d0..d45c96c 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -714,7 +714,7 @@ static void tcp_keepalive_timer (struct timer_list *t) tcp_mstamp_refresh(tp); if (sk->sk_state == TCP_FIN_WAIT2 && sock_flag(sk, SOCK_DEAD)) { - if (tp->linger2 >= 0) { + if (READ_ONCE(tp->linger2) >= 0) { const int tmo = tcp_fin_time(sk) - TCP_TIMEWAIT_LEN; if (tmo > 0) { -- 2.7.4