tcp_metrics: annotate data-races around tm->tcpm_vals[]

[platform/kernel/linux-starfive.git] / net / ipv4 / tcp_metrics.c

diff --git a/net/ipv4/tcp_metrics.c b/net/ipv4/tcp_metrics.c
index 131fa30..fd4ab7a 100644 (file)
--- a/net/ipv4/tcp_metrics.c
+++ b/net/ipv4/tcp_metrics.c
@@ -63,17 +63,19 @@ static bool tcp_metric_locked(struct tcp_metrics_block *tm,
        return READ_ONCE(tm->tcpm_lock) & (1 << idx);
 }
 
-static u32 tcp_metric_get(struct tcp_metrics_block *tm,
+static u32 tcp_metric_get(const struct tcp_metrics_block *tm,
                          enum tcp_metric_index idx)
 {
-       return tm->tcpm_vals[idx];
+       /* Paired with WRITE_ONCE() in tcp_metric_set() */
+       return READ_ONCE(tm->tcpm_vals[idx]);
 }
 
 static void tcp_metric_set(struct tcp_metrics_block *tm,
                           enum tcp_metric_index idx,
                           u32 val)
 {
-       tm->tcpm_vals[idx] = val;
+       /* Paired with READ_ONCE() in tcp_metric_get() */
+       WRITE_ONCE(tm->tcpm_vals[idx], val);
 }
 
 static bool addr_same(const struct inetpeer_addr *a,
@@ -115,13 +117,16 @@ static void tcpm_suck_dst(struct tcp_metrics_block *tm,
        WRITE_ONCE(tm->tcpm_lock, val);
 
        msval = dst_metric_raw(dst, RTAX_RTT);
-       tm->tcpm_vals[TCP_METRIC_RTT] = msval * USEC_PER_MSEC;
+       tcp_metric_set(tm, TCP_METRIC_RTT, msval * USEC_PER_MSEC);
 
        msval = dst_metric_raw(dst, RTAX_RTTVAR);
-       tm->tcpm_vals[TCP_METRIC_RTTVAR] = msval * USEC_PER_MSEC;
-       tm->tcpm_vals[TCP_METRIC_SSTHRESH] = dst_metric_raw(dst, RTAX_SSTHRESH);
-       tm->tcpm_vals[TCP_METRIC_CWND] = dst_metric_raw(dst, RTAX_CWND);
-       tm->tcpm_vals[TCP_METRIC_REORDERING] = dst_metric_raw(dst, RTAX_REORDERING);
+       tcp_metric_set(tm, TCP_METRIC_RTTVAR, msval * USEC_PER_MSEC);
+       tcp_metric_set(tm, TCP_METRIC_SSTHRESH,
+                      dst_metric_raw(dst, RTAX_SSTHRESH));
+       tcp_metric_set(tm, TCP_METRIC_CWND,
+                      dst_metric_raw(dst, RTAX_CWND));
+       tcp_metric_set(tm, TCP_METRIC_REORDERING,
+                      dst_metric_raw(dst, RTAX_REORDERING));
        if (fastopen_clear) {
                tm->tcpm_fastopen.mss = 0;
                tm->tcpm_fastopen.syn_loss = 0;
@@ -667,7 +672,7 @@ static int tcp_metrics_fill_info(struct sk_buff *msg,
                if (!nest)
                        goto nla_put_failure;
                for (i = 0; i < TCP_METRIC_MAX_KERNEL + 1; i++) {
-                       u32 val = tm->tcpm_vals[i];
+                       u32 val = tcp_metric_get(tm, i);
 
                        if (!val)
                                continue;