From 5a9071a760a61b00260334ad576fe60debafaafc Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 2 Oct 2024 17:30:40 +0000 Subject: tcp: annotate data-races around icsk->icsk_pending icsk->icsk_pending can be read locklessly already. Following patch in the series will add another lockless read. Add smp_load_acquire() and smp_store_release() annotations because following patch will add a test in tcp_write_timer(), and READ_ONCE()/WRITE_ONCE() alone would possibly lead to races. Signed-off-by: Eric Dumazet Link: https://patch.msgid.link/20241002173042.917928-2-edumazet@google.com Signed-off-by: Jakub Kicinski --- net/ipv6/tcp_ipv6.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'net/ipv6/tcp_ipv6.c') diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index d71ab4e1efe1..7634c0be6acb 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -2177,6 +2177,7 @@ static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i) const struct tcp_sock *tp = tcp_sk(sp); const struct inet_connection_sock *icsk = inet_csk(sp); const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq; + u8 icsk_pending; int rx_queue; int state; @@ -2185,12 +2186,13 @@ static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i) destp = ntohs(inet->inet_dport); srcp = ntohs(inet->inet_sport); - if (icsk->icsk_pending == ICSK_TIME_RETRANS || - icsk->icsk_pending == ICSK_TIME_REO_TIMEOUT || - icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) { + icsk_pending = smp_load_acquire(&icsk->icsk_pending); + if (icsk_pending == ICSK_TIME_RETRANS || + icsk_pending == ICSK_TIME_REO_TIMEOUT || + icsk_pending == ICSK_TIME_LOSS_PROBE) { timer_active = 1; timer_expires = icsk->icsk_timeout; - } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) { + } else if (icsk_pending == ICSK_TIME_PROBE0) { timer_active = 4; timer_expires = icsk->icsk_timeout; } else if (timer_pending(&sp->sk_timer)) { -- cgit v1.2.3