tcp: annotate data-races around icsk->icsk_probes_out

icsk->icsk_probes_out is read locklessly from inet_sk_diag_fill(),
get_tcp4_sock() and get_tcp6_sock().

Add corresponding READ_ONCE()/WRITE_ONCE() annotations.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Link: https://patch.msgid.link/20250822091727.835869-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index 35c1579e5bd4cef4a8c44d03ed1af16fe1735ac0..549f1f521f4f6f9e5fe347767ed0f98f4aa9b62a 100644 (file)
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -318,12 +318,12 @@ int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk,
                        jiffies_delta_to_msecs(icsk_timeout(icsk) - jiffies);
        } else if (icsk_pending == ICSK_TIME_PROBE0) {
                r->idiag_timer = 4;
-               r->idiag_retrans = icsk->icsk_probes_out;
+               r->idiag_retrans = READ_ONCE(icsk->icsk_probes_out);
                r->idiag_expires =
                        jiffies_delta_to_msecs(icsk_timeout(icsk) - jiffies);
        } else if (timer_pending(&sk->sk_timer)) {
                r->idiag_timer = 2;
-               r->idiag_retrans = icsk->icsk_probes_out;
+               r->idiag_retrans = READ_ONCE(icsk->icsk_probes_out);
                r->idiag_expires =
                        jiffies_delta_to_msecs(sk->sk_timer.expires - jiffies);
        }

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 4728801d06a7a1dabfaab2ce27a6dcfa36ffce7f..9bc8317e92b7952871f07ae11a9c2eaa7d3a9e65 100644 (file)
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -3376,7 +3376,7 @@ int tcp_disconnect(struct sock *sk, int flags)
        WRITE_ONCE(tp->write_seq, seq);
 
        icsk->icsk_backoff = 0;
-       icsk->icsk_probes_out = 0;
+       WRITE_ONCE(icsk->icsk_probes_out, 0);
        icsk->icsk_probes_tstamp = 0;
        icsk->icsk_rto = TCP_TIMEOUT_INIT;
        WRITE_ONCE(icsk->icsk_rto_min, TCP_RTO_MIN);

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 3baf3bef0d8328bc21150d6be45b32179da38f90..a52a747d8a55e6a405d2fb1608e979abceb51c07 100644 (file)
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -3913,7 +3913,7 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
         * log. Something worked...
         */
        WRITE_ONCE(sk->sk_err_soft, 0);
-       icsk->icsk_probes_out = 0;
+       WRITE_ONCE(icsk->icsk_probes_out, 0);
        tp->rcv_tstamp = tcp_jiffies32;
        if (!prior_packets)
                goto no_queue;

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 5d549dfd4e601eedb7c5cc3f3e503a5bef7ed4a4..9543f153835908286384defa787e2a707fb8dbda 100644 (file)
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2960,7 +2960,7 @@ static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i)
                jiffies_delta_to_clock_t(timer_expires - jiffies),
                READ_ONCE(icsk->icsk_retransmits),
                from_kuid_munged(seq_user_ns(f), sk_uid(sk)),
-               icsk->icsk_probes_out,
+               READ_ONCE(icsk->icsk_probes_out),
                sock_i_ino(sk),
                refcount_read(&sk->sk_refcnt), sk,
                jiffies_to_clock_t(icsk->icsk_rto),

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 72969c27eaaae4123dbc30bd8709a30be14d6830..06b26a6efd628e85f97bdb7253c344565b0ed56d 100644 (file)
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -4394,13 +4394,13 @@ void tcp_send_probe0(struct sock *sk)
 
        if (tp->packets_out || tcp_write_queue_empty(sk)) {
                /* Cancel probe timer, if it is not required. */
-               icsk->icsk_probes_out = 0;
+               WRITE_ONCE(icsk->icsk_probes_out, 0);
                icsk->icsk_backoff = 0;
                icsk->icsk_probes_tstamp = 0;
                return;
        }
 
-       icsk->icsk_probes_out++;
+       WRITE_ONCE(icsk->icsk_probes_out, icsk->icsk_probes_out + 1);
        if (err <= 0) {
                if (icsk->icsk_backoff < READ_ONCE(net->ipv4.sysctl_tcp_retries2))
                        icsk->icsk_backoff++;

diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index 8b11ab4cc9524f0e0066f474044a4c585115ec29..2dd73a4e8e517ab46d69ab655a6b1a9cbcaf7c1e 100644 (file)
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -392,7 +392,7 @@ static void tcp_probe_timer(struct sock *sk)
        int max_probes;
 
        if (tp->packets_out || !skb) {
-               icsk->icsk_probes_out = 0;
+               WRITE_ONCE(icsk->icsk_probes_out, 0);
                icsk->icsk_probes_tstamp = 0;
                return;
        }
@@ -839,7 +839,7 @@ static void tcp_keepalive_timer(struct timer_list *t)
                        goto out;
                }
                if (tcp_write_wakeup(sk, LINUX_MIB_TCPKEEPALIVE) <= 0) {
-                       icsk->icsk_probes_out++;
+                       WRITE_ONCE(icsk->icsk_probes_out, icsk->icsk_probes_out + 1);
                        elapsed = keepalive_intvl_when(tp);
                } else {
                        /* If keepalive was lost due to local congestion,

diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 7b177054452b983d3f49a06869950565c03c13ee..5620d9e50e195894fb0289d5bb8963579e14429e 100644 (file)
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -2232,7 +2232,7 @@ static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
                   jiffies_delta_to_clock_t(timer_expires - jiffies),
                   READ_ONCE(icsk->icsk_retransmits),
                   from_kuid_munged(seq_user_ns(seq), sk_uid(sp)),
-                  icsk->icsk_probes_out,
+                  READ_ONCE(icsk->icsk_probes_out),
                   sock_i_ino(sp),
                   refcount_read(&sp->sk_refcnt), sp,
                   jiffies_to_clock_t(icsk->icsk_rto),