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authorEric Dumazet <edumazet@google.com>2024-10-02 17:30:40 +0000
committerJakub Kicinski <kuba@kernel.org>2024-10-04 15:34:39 -0700
commit5a9071a760a61b00260334ad576fe60debafaafc (patch)
tree12c4ab5c51e735e4a18e4dbc2b3113d417456fbf /net/ipv4/tcp_ipv4.c
parentd454184bba235d3a5d1ff4b30597b43a08c00f70 (diff)
downloadlwn-5a9071a760a61b00260334ad576fe60debafaafc.tar.gz
lwn-5a9071a760a61b00260334ad576fe60debafaafc.zip
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 <edumazet@google.com> Link: https://patch.msgid.link/20241002173042.917928-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/ipv4/tcp_ipv4.c')
-rw-r--r--net/ipv4/tcp_ipv4.c10
1 files changed, 6 insertions, 4 deletions
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 5afe5e57c89b..985028434f64 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2900,15 +2900,17 @@ static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i)
__be32 src = inet->inet_rcv_saddr;
__u16 destp = ntohs(inet->inet_dport);
__u16 srcp = ntohs(inet->inet_sport);
+ u8 icsk_pending;
int rx_queue;
int state;
- 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(&sk->sk_timer)) {