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| author | Eric Dumazet <edumazet@google.com> | 2023-02-27 11:33:36 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2023-02-27 22:59:29 +0300 |
| commit | 580f98cc33a260bb8c6a39ae2921b29586b84fdf (patch) | |
| tree | ef2eab5f3e3a3cd60992ce51a8b8abff49e60ab9 /net/ipv4 | |
| parent | 972074ea88402e9b1b29c3a8d3d6d1aadaff624e (diff) | |
| download | linux-580f98cc33a260bb8c6a39ae2921b29586b84fdf.tar.xz | |
tcp: tcp_check_req() can be called from process context
This is a follow up of commit 0a375c822497 ("tcp: tcp_rtx_synack()
can be called from process context").
Frederick Lawler reported another "__this_cpu_add() in preemptible"
warning caused by the same reason.
In my former patch I took care of tcp_rtx_synack()
but forgot that tcp_check_req() also contained some SNMP updates.
Note that some parts of tcp_check_req() always run in BH context,
I added a comment to clarify this.
Fixes: 8336886f786f ("tcp: TCP Fast Open Server - support TFO listeners")
Link: https://lore.kernel.org/netdev/8cd33923-a21d-397c-e46b-2a068c287b03@cloudflare.com/T/
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Frederick Lawler <fred@cloudflare.com>
Tested-by: Frederick Lawler <fred@cloudflare.com>
Link: https://lore.kernel.org/r/20230227083336.4153089-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/tcp_minisocks.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index e002f2e1d4f2..9a7ef7732c24 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -597,6 +597,9 @@ EXPORT_SYMBOL(tcp_create_openreq_child); * validation and inside tcp_v4_reqsk_send_ack(). Can we do better? * * We don't need to initialize tmp_opt.sack_ok as we don't use the results + * + * Note: If @fastopen is true, this can be called from process context. + * Otherwise, this is from BH context. */ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb, @@ -748,7 +751,7 @@ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb, &tcp_rsk(req)->last_oow_ack_time)) req->rsk_ops->send_ack(sk, skb, req); if (paws_reject) - __NET_INC_STATS(sock_net(sk), LINUX_MIB_PAWSESTABREJECTED); + NET_INC_STATS(sock_net(sk), LINUX_MIB_PAWSESTABREJECTED); return NULL; } @@ -767,7 +770,7 @@ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb, * "fourth, check the SYN bit" */ if (flg & (TCP_FLAG_RST|TCP_FLAG_SYN)) { - __TCP_INC_STATS(sock_net(sk), TCP_MIB_ATTEMPTFAILS); + TCP_INC_STATS(sock_net(sk), TCP_MIB_ATTEMPTFAILS); goto embryonic_reset; } |