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| author | Eric Dumazet <edumazet@google.com> | 2024-06-03 15:51:06 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2024-06-05 12:30:09 +0100 |
| commit | 69e0b33a7fce4d96649b9fa32e56b696921aa48e (patch) | |
| tree | d0f565a124d88f3ac9a486f228cb9bf76a24e24a /net/ipv4/tcp_ipv4.c | |
| parent | b907194a5d5bcd3b01d28d095f6a4d9fcd9c5354 (diff) | |
| download | lwn-69e0b33a7fce4d96649b9fa32e56b696921aa48e.tar.gz lwn-69e0b33a7fce4d96649b9fa32e56b696921aa48e.zip | |
tcp: annotate data-races around tw->tw_ts_recent and tw->tw_ts_recent_stamp
These fields can be read and written locklessly, add annotations
around these minor races.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_ipv4.c')
| -rw-r--r-- | net/ipv4/tcp_ipv4.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 04044605cadf..3ef4b274c24b 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -114,6 +114,7 @@ int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp) const struct inet_timewait_sock *tw = inet_twsk(sktw); const struct tcp_timewait_sock *tcptw = tcp_twsk(sktw); struct tcp_sock *tp = tcp_sk(sk); + int ts_recent_stamp; if (reuse == 2) { /* Still does not detect *everything* that goes through @@ -152,9 +153,10 @@ int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp) If TW bucket has been already destroyed we fall back to VJ's scheme and use initial timestamp retrieved from peer table. */ - if (tcptw->tw_ts_recent_stamp && + ts_recent_stamp = READ_ONCE(tcptw->tw_ts_recent_stamp); + if (ts_recent_stamp && (!twp || (reuse && time_after32(ktime_get_seconds(), - tcptw->tw_ts_recent_stamp)))) { + ts_recent_stamp)))) { /* inet_twsk_hashdance() sets sk_refcnt after putting twsk * and releasing the bucket lock. */ @@ -178,8 +180,8 @@ int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp) if (!seq) seq = 1; WRITE_ONCE(tp->write_seq, seq); - tp->rx_opt.ts_recent = tcptw->tw_ts_recent; - tp->rx_opt.ts_recent_stamp = tcptw->tw_ts_recent_stamp; + tp->rx_opt.ts_recent = READ_ONCE(tcptw->tw_ts_recent); + tp->rx_opt.ts_recent_stamp = ts_recent_stamp; } return 1; @@ -1064,7 +1066,7 @@ static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb) tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt, tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale, tcp_tw_tsval(tcptw), - tcptw->tw_ts_recent, + READ_ONCE(tcptw->tw_ts_recent), tw->tw_bound_dev_if, &key, tw->tw_transparent ? IP_REPLY_ARG_NOSRCCHECK : 0, tw->tw_tos, |