diff options
| author | Eric Dumazet <edumazet@google.com> | 2022-04-06 02:35:38 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2022-04-06 22:05:41 +0300 |
| commit | 40570375356c874b1578e05c1dcc3ff7c1322dbe (patch) | |
| tree | 54c7a52bfdd4e302f877e93dc94adb09cfa3aac4 /net/ipv4/tcp_htcp.c | |
| parent | 487dc3ca60e3e420d54bcc613cb49e8e85f34569 (diff) | |
| download | linux-40570375356c874b1578e05c1dcc3ff7c1322dbe.tar.xz | |
tcp: add accessors to read/set tp->snd_cwnd
We had various bugs over the years with code
breaking the assumption that tp->snd_cwnd is greater
than zero.
Lately, syzbot reported the WARN_ON_ONCE(!tp->prior_cwnd) added
in commit 8b8a321ff72c ("tcp: fix zero cwnd in tcp_cwnd_reduction")
can trigger, and without a repro we would have to spend
considerable time finding the bug.
Instead of complaining too late, we want to catch where
and when tp->snd_cwnd is set to an illegal value.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Suggested-by: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Link: https://lore.kernel.org/r/20220405233538.947344-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/ipv4/tcp_htcp.c')
| -rw-r--r-- | net/ipv4/tcp_htcp.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/net/ipv4/tcp_htcp.c b/net/ipv4/tcp_htcp.c index 55adcfcf96fe..52b1f2665dfa 100644 --- a/net/ipv4/tcp_htcp.c +++ b/net/ipv4/tcp_htcp.c @@ -124,7 +124,7 @@ static void measure_achieved_throughput(struct sock *sk, ca->packetcount += sample->pkts_acked; - if (ca->packetcount >= tp->snd_cwnd - (ca->alpha >> 7 ? : 1) && + if (ca->packetcount >= tcp_snd_cwnd(tp) - (ca->alpha >> 7 ? : 1) && now - ca->lasttime >= ca->minRTT && ca->minRTT > 0) { __u32 cur_Bi = ca->packetcount * HZ / (now - ca->lasttime); @@ -225,7 +225,7 @@ static u32 htcp_recalc_ssthresh(struct sock *sk) const struct htcp *ca = inet_csk_ca(sk); htcp_param_update(sk); - return max((tp->snd_cwnd * ca->beta) >> 7, 2U); + return max((tcp_snd_cwnd(tp) * ca->beta) >> 7, 2U); } static void htcp_cong_avoid(struct sock *sk, u32 ack, u32 acked) @@ -242,9 +242,9 @@ static void htcp_cong_avoid(struct sock *sk, u32 ack, u32 acked) /* In dangerous area, increase slowly. * In theory this is tp->snd_cwnd += alpha / tp->snd_cwnd */ - if ((tp->snd_cwnd_cnt * ca->alpha)>>7 >= tp->snd_cwnd) { - if (tp->snd_cwnd < tp->snd_cwnd_clamp) - tp->snd_cwnd++; + if ((tp->snd_cwnd_cnt * ca->alpha)>>7 >= tcp_snd_cwnd(tp)) { + if (tcp_snd_cwnd(tp) < tp->snd_cwnd_clamp) + tcp_snd_cwnd_set(tp, tcp_snd_cwnd(tp) + 1); tp->snd_cwnd_cnt = 0; htcp_alpha_update(ca); } else |