diff options
| author | Kuniyuki Iwashima <kuniyu@amazon.com> | 2022-07-20 18:50:17 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2022-07-22 13:06:17 +0200 |
| commit | ab1ba21b523ab496b1a4a8e396333b24b0a18f9a (patch) | |
| tree | 4d454799a04c360beb15452bb5f1f0a1dea08b8e /net | |
| parent | tcp: Fix a data-race around sysctl_tcp_nometrics_save. (diff) | |
| download | linux-ab1ba21b523ab496b1a4a8e396333b24b0a18f9a.tar.xz linux-ab1ba21b523ab496b1a4a8e396333b24b0a18f9a.zip | |
tcp: Fix data-races around sysctl_tcp_no_ssthresh_metrics_save.
While reading sysctl_tcp_no_ssthresh_metrics_save, it can be changed
concurrently. Thus, we need to add READ_ONCE() to its readers.
Fixes: 65e6d90168f3 ("net-tcp: Disable TCP ssthresh metrics cache by default")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/tcp_metrics.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/net/ipv4/tcp_metrics.c b/net/ipv4/tcp_metrics.c index 9dcc418a26f2..d58e672be31c 100644 --- a/net/ipv4/tcp_metrics.c +++ b/net/ipv4/tcp_metrics.c @@ -385,7 +385,7 @@ void tcp_update_metrics(struct sock *sk) if (tcp_in_initial_slowstart(tp)) { /* Slow start still did not finish. */ - if (!net->ipv4.sysctl_tcp_no_ssthresh_metrics_save && + if (!READ_ONCE(net->ipv4.sysctl_tcp_no_ssthresh_metrics_save) && !tcp_metric_locked(tm, TCP_METRIC_SSTHRESH)) { val = tcp_metric_get(tm, TCP_METRIC_SSTHRESH); if (val && (tcp_snd_cwnd(tp) >> 1) > val) @@ -401,7 +401,7 @@ void tcp_update_metrics(struct sock *sk) } else if (!tcp_in_slow_start(tp) && icsk->icsk_ca_state == TCP_CA_Open) { /* Cong. avoidance phase, cwnd is reliable. */ - if (!net->ipv4.sysctl_tcp_no_ssthresh_metrics_save && + if (!READ_ONCE(net->ipv4.sysctl_tcp_no_ssthresh_metrics_save) && !tcp_metric_locked(tm, TCP_METRIC_SSTHRESH)) tcp_metric_set(tm, TCP_METRIC_SSTHRESH, max(tcp_snd_cwnd(tp) >> 1, tp->snd_ssthresh)); @@ -418,7 +418,7 @@ void tcp_update_metrics(struct sock *sk) tcp_metric_set(tm, TCP_METRIC_CWND, (val + tp->snd_ssthresh) >> 1); } - if (!net->ipv4.sysctl_tcp_no_ssthresh_metrics_save && + if (!READ_ONCE(net->ipv4.sysctl_tcp_no_ssthresh_metrics_save) && !tcp_metric_locked(tm, TCP_METRIC_SSTHRESH)) { val = tcp_metric_get(tm, TCP_METRIC_SSTHRESH); if (val && tp->snd_ssthresh > val) @@ -463,7 +463,7 @@ void tcp_init_metrics(struct sock *sk) if (tcp_metric_locked(tm, TCP_METRIC_CWND)) tp->snd_cwnd_clamp = tcp_metric_get(tm, TCP_METRIC_CWND); - val = net->ipv4.sysctl_tcp_no_ssthresh_metrics_save ? + val = READ_ONCE(net->ipv4.sysctl_tcp_no_ssthresh_metrics_save) ? 0 : tcp_metric_get(tm, TCP_METRIC_SSTHRESH); if (val) { tp->snd_ssthresh = val; |