From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5358E534475 for ; Thu, 17 Sep 2026 13:34:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789652092; cv=none; b=C+Z7yMLdS/2N7aXFGJj93pvYyXX9YrmeseDX4toUTOs8Fu00M2EwfRUKlJsnoIJuGE+krlOmEUsQ+M9QN2oO5a8QePTmZHa0IUNweKdBOFkxtCw6Jdy9LAnqNYK+w1wgqmLPiqkPCnr0FAY3L9nS75clq5LXosoWBcCGpvI36CE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789652092; c=relaxed/simple; bh=OJfGnb52eBOYWglmJbZpz0pNPaVTANDl6LDhXhZRAt4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=MnVsbl2AnOnju4MleH76jlIBXvO6BdiwM8XDLlhkoBfvdxLuUT21mmrSQVrNIv7Q516jbiV+UMGFKmHwYRJ/4tWkm2fgPp5rIst1Vt3aMdf9jxhrHDqgFsCfa38eVWtHhpW56nvMP8Tr1p2cBuyQQ6Egn+HjJFNh2hiq4zrgbY4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=aLfs4UPr; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="aLfs4UPr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 004EB1F000FF; Thu, 17 Sep 2026 13:34:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789652082; bh=NgyKiXAuacYzOJlNHDsbz3y7f+oMrQ/BF7s7Uld+yQY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=aLfs4UPrNTcPhoWrnJ4paMRq17A3PhIWMI7mEYNeyc/I1jtCW3ucHsek+Jtbw5H92 jDEFxTv/a9daTX8z38vJwt3Z+bNtL3sCtVGCbtUe8EPe05WugtEKgA30J1BNIn/WcC 4xQFHjdfbRaXpYBseAUebYz5oTfwPrCNRGpnm4rzR2On/Zj10Y4AnVngf7eU6ra/GH cCGKBywDHNNblvrvNL6yaJTRP94xroZbKVlprnBJUxADV4kAZCAOgtfYMwemhyNT17 8v7soc2vUsl0BBPV2aXLy4wAfCfSxJG8lGWHoSuCzPcMLPWOpyXiKdoQOFJ58sh75j n1Ql2beyNunQw== From: Sasha Levin To: stable@vger.kernel.org Cc: Eric Dumazet , Kuniyuki Iwashima , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.1.y 1/2] tcp: introduce icsk->icsk_keepalive_timer Date: Thu, 17 Sep 2026 09:34:39 -0400 Message-ID: <20260917133440.405725-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026091622-thieving-raffle-4915@gregkh> References: <2026091622-thieving-raffle-4915@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Eric Dumazet [ Upstream commit 08dfe370239e53494453cee1e2ded2cdaa1efd12 ] sk->sk_timer has been used for TCP keepalives. Keepalive timers are not in fast path, we want to use sk->sk_timer storage for retransmit timers, for better cache locality. Create icsk->icsk_keepalive_timer and change keepalive code to no longer use sk->sk_timer. Added space is reclaimed in the following patch. This includes changes to MPTCP, which was also using sk_timer. Alias icsk->mptcp_tout_timer and icsk->icsk_keepalive_timer for inet_sk_diag_fill() sake. Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20251124175013.1473655-4-edumazet@google.com Signed-off-by: Jakub Kicinski Backport to 6.1 as a dependency of 85c580b0d859 ("mptcp: prevent race between disconnect() and rtx"): Keep icsk_timeout and the existing TCP retransmit timer. Update the existing inet_csk keepalive helpers in inet_connection_sock.c instead of introducing the newer TCP helpers, and use from_timer() in the callbacks. Adjust the DCCP callback, since DCCP still shares the inet_csk timer setup in this branch. Omit the absent net_cachelines document. Also alias sk_timer as mptcp_retransmit_timer and move all MPTCP retransmit timer users there. The target directly stops this timer and the new mptcp_tout_timer, so both names must identify the timers actually in use. Initialize the MPTCP icsk_rto_min to this branch's TCP_RTO_MIN so the target restores a valid retransmit interval during disconnect. No functions are added. [ sashal: Reduced backport -- upstream 08dfe370239e5 touches 11 file(s), this backport carries 12. Not backported here: Documentation/networking/net_cachelines/inet_connection_sock.rst This note is generated from the file lists only; see the resolution record for the reasoning. ] Stable-dep-of: 85c580b0d859 ("mptcp: prevent race between disconnect() and rtx") Signed-off-by: Sasha Levin --- include/net/inet_connection_sock.h | 11 ++++++-- include/net/sock.h | 6 +++- net/dccp/timer.c | 4 ++- net/ipv4/inet_connection_sock.c | 10 +++---- net/ipv4/inet_diag.c | 4 +-- net/ipv4/tcp_ipv4.c | 4 +-- net/ipv4/tcp_timer.c | 5 ++-- net/ipv6/tcp_ipv6.c | 4 +-- net/mptcp/protocol.c | 28 +++++++++---------- net/mptcp/protocol.h | 2 +- .../selftests/bpf/progs/bpf_iter_tcp4.c | 4 +-- .../selftests/bpf/progs/bpf_iter_tcp6.c | 4 +-- 12 files changed, 49 insertions(+), 37 deletions(-) diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h index 9760ba0516b6c..51be99667a23c 100644 --- a/include/net/inet_connection_sock.h +++ b/include/net/inet_connection_sock.h @@ -63,6 +63,9 @@ struct inet_connection_sock_af_ops { * @icsk_bind2_hash: Bind node in the bhash2 table * @icsk_timeout: Timeout * @icsk_retransmit_timer: Resend (no ack) + * @icsk_delack_timer: Delayed ACK timer + * @icsk_keepalive_timer: Keepalive timer + * @mptcp_tout_timer: MPTCP timeout timer * @icsk_rto: Retransmit timeout * @icsk_pmtu_cookie Last pmtu seen by socket * @icsk_ca_ops Pluggable congestion control hook @@ -89,8 +92,12 @@ struct inet_connection_sock { struct inet_bind_bucket *icsk_bind_hash; struct inet_bind2_bucket *icsk_bind2_hash; unsigned long icsk_timeout; - struct timer_list icsk_retransmit_timer; - struct timer_list icsk_delack_timer; + struct timer_list icsk_retransmit_timer; + struct timer_list icsk_delack_timer; + union { + struct timer_list icsk_keepalive_timer; + struct timer_list mptcp_tout_timer; + }; __u32 icsk_rto; __u32 icsk_rto_min; __u32 icsk_delack_max; diff --git a/include/net/sock.h b/include/net/sock.h index 9fe621f985740..1aada87bde5f6 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -315,6 +315,7 @@ struct sk_filter; * @sk_txrehash: enable TX hash rethink * @sk_filter: socket filtering instructions * @sk_timer: sock cleanup timer + * @mptcp_retransmit_timer: MPTCP retransmit timer * @sk_stamp: time stamp of last packet received * @sk_stamp_seq: lock for accessing sk_stamp on 32 bit architectures only * @sk_tsflags: SO_TIMESTAMPING flags @@ -459,7 +460,10 @@ struct sock { __u32 sk_dst_pending_confirm; u32 sk_pacing_status; /* see enum sk_pacing */ long sk_sndtimeo; - struct timer_list sk_timer; + union { + struct timer_list sk_timer; + struct timer_list mptcp_retransmit_timer; + }; __u32 sk_priority; __u32 sk_mark; unsigned long sk_pacing_rate; /* bytes per second */ diff --git a/net/dccp/timer.c b/net/dccp/timer.c index 27a3b37acd2ef..ff9c0184e3f68 100644 --- a/net/dccp/timer.c +++ b/net/dccp/timer.c @@ -160,7 +160,9 @@ static void dccp_write_timer(struct timer_list *t) static void dccp_keepalive_timer(struct timer_list *t) { - struct sock *sk = from_timer(sk, t, sk_timer); + struct inet_connection_sock *icsk = + from_timer(icsk, t, icsk_keepalive_timer); + struct sock *sk = &icsk->icsk_inet.sk; pr_err("dccp should not use a keepalive timer !\n"); sock_put(sk); diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index 6184534aa1bf5..5e31302b42505 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -749,7 +749,7 @@ void inet_csk_init_xmit_timers(struct sock *sk, timer_setup(&icsk->icsk_retransmit_timer, retransmit_handler, 0); timer_setup(&icsk->icsk_delack_timer, delack_handler, 0); - timer_setup(&sk->sk_timer, keepalive_handler, 0); + timer_setup(&icsk->icsk_keepalive_timer, keepalive_handler, 0); icsk->icsk_pending = icsk->icsk_ack.pending = 0; } EXPORT_SYMBOL(inet_csk_init_xmit_timers); @@ -762,7 +762,7 @@ void inet_csk_clear_xmit_timers(struct sock *sk) sk_stop_timer(sk, &icsk->icsk_retransmit_timer); sk_stop_timer(sk, &icsk->icsk_delack_timer); - sk_stop_timer(sk, &sk->sk_timer); + sk_stop_timer(sk, &icsk->icsk_keepalive_timer); } EXPORT_SYMBOL(inet_csk_clear_xmit_timers); @@ -777,18 +777,18 @@ void inet_csk_clear_xmit_timers_sync(struct sock *sk) sk_stop_timer_sync(sk, &icsk->icsk_retransmit_timer); sk_stop_timer_sync(sk, &icsk->icsk_delack_timer); - sk_stop_timer_sync(sk, &sk->sk_timer); + sk_stop_timer_sync(sk, &icsk->icsk_keepalive_timer); } void inet_csk_delete_keepalive_timer(struct sock *sk) { - sk_stop_timer(sk, &sk->sk_timer); + sk_stop_timer(sk, &inet_csk(sk)->icsk_keepalive_timer); } EXPORT_SYMBOL(inet_csk_delete_keepalive_timer); void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len) { - sk_reset_timer(sk, &sk->sk_timer, jiffies + len); + sk_reset_timer(sk, &inet_csk(sk)->icsk_keepalive_timer, jiffies + len); } EXPORT_SYMBOL(inet_csk_reset_keepalive_timer); diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c index 2bd5d0ed7a6fc..02d8a63f39ebf 100644 --- a/net/ipv4/inet_diag.c +++ b/net/ipv4/inet_diag.c @@ -310,11 +310,11 @@ int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk, r->idiag_retrans = icsk->icsk_probes_out; r->idiag_expires = jiffies_delta_to_msecs(icsk->icsk_timeout - jiffies); - } else if (timer_pending(&sk->sk_timer)) { + } else if (timer_pending(&icsk->icsk_keepalive_timer)) { r->idiag_timer = 2; r->idiag_retrans = icsk->icsk_probes_out; r->idiag_expires = - jiffies_delta_to_msecs(sk->sk_timer.expires - jiffies); + jiffies_delta_to_msecs(icsk->icsk_keepalive_timer.expires - jiffies); } if ((ext & (1 << (INET_DIAG_INFO - 1))) && handler->idiag_info_size) { diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index ec3b0aa0a6260..aa99d7cd4bfec 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -2646,9 +2646,9 @@ static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i) } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) { timer_active = 4; timer_expires = icsk->icsk_timeout; - } else if (timer_pending(&sk->sk_timer)) { + } else if (timer_pending(&icsk->icsk_keepalive_timer)) { timer_active = 2; - timer_expires = sk->sk_timer.expires; + timer_expires = icsk->icsk_keepalive_timer.expires; } else { timer_active = 0; timer_expires = jiffies; diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c index 3662b49ce71ae..d086026018d62 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -706,8 +706,9 @@ EXPORT_SYMBOL_GPL(tcp_set_keepalive); static void tcp_keepalive_timer (struct timer_list *t) { - struct sock *sk = from_timer(sk, t, sk_timer); - struct inet_connection_sock *icsk = inet_csk(sk); + struct inet_connection_sock *icsk = + from_timer(icsk, t, icsk_keepalive_timer); + struct sock *sk = &icsk->icsk_inet.sk; struct tcp_sock *tp = tcp_sk(sk); u32 elapsed; diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index d3952b058453f..3d7bfa0e7be42 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -2000,9 +2000,9 @@ static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i) } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) { timer_active = 4; timer_expires = icsk->icsk_timeout; - } else if (timer_pending(&sp->sk_timer)) { + } else if (timer_pending(&icsk->icsk_keepalive_timer)) { timer_active = 2; - timer_expires = sp->sk_timer.expires; + timer_expires = icsk->icsk_keepalive_timer.expires; } else { timer_active = 0; timer_expires = jiffies; diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 2ce20884d7305..70810fa673c34 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -426,9 +426,7 @@ static bool __mptcp_move_skb(struct mptcp_sock *msk, struct sock *ssk, static void mptcp_stop_rtx_timer(struct sock *sk) { - struct inet_connection_sock *icsk = inet_csk(sk); - - sk_stop_timer(sk, &icsk->icsk_retransmit_timer); + sk_stop_timer(sk, &sk->mptcp_retransmit_timer); mptcp_sk(sk)->timer_ival = 0; } @@ -976,12 +974,11 @@ static void __mptcp_flush_join_list(struct sock *sk, struct list_head *join_list static bool mptcp_rtx_timer_pending(struct sock *sk) { - return timer_pending(&inet_csk(sk)->icsk_retransmit_timer); + return timer_pending(&sk->mptcp_retransmit_timer); } static void mptcp_reset_rtx_timer(struct sock *sk) { - struct inet_connection_sock *icsk = inet_csk(sk); unsigned long tout; /* prevent rescheduling on close */ @@ -989,7 +986,7 @@ static void mptcp_reset_rtx_timer(struct sock *sk) return; tout = mptcp_sk(sk)->timer_ival; - sk_reset_timer(sk, &icsk->icsk_retransmit_timer, jiffies + tout); + sk_reset_timer(sk, &sk->mptcp_retransmit_timer, jiffies + tout); } bool mptcp_schedule_work(struct sock *sk) @@ -2347,9 +2344,7 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, static void mptcp_retransmit_timer(struct timer_list *t) { - struct inet_connection_sock *icsk = from_timer(icsk, t, - icsk_retransmit_timer); - struct sock *sk = &icsk->icsk_inet.sk; + struct sock *sk = from_timer(sk, t, mptcp_retransmit_timer); struct mptcp_sock *msk = mptcp_sk(sk); bh_lock_sock(sk); @@ -2367,7 +2362,9 @@ static void mptcp_retransmit_timer(struct timer_list *t) static void mptcp_tout_timer(struct timer_list *t) { - struct sock *sk = from_timer(sk, t, sk_timer); + struct inet_connection_sock *icsk = + from_timer(icsk, t, mptcp_tout_timer); + struct sock *sk = &icsk->icsk_inet.sk; mptcp_schedule_work(sk); sock_put(sk); @@ -2799,7 +2796,7 @@ void mptcp_reset_tout_timer(struct mptcp_sock *msk, unsigned long fail_tout) */ timeout = inet_csk(sk)->icsk_mtup.probe_timestamp ? close_timeout : fail_tout; - sk_reset_timer(sk, &sk->sk_timer, timeout); + sk_reset_timer(sk, &inet_csk(sk)->mptcp_tout_timer, timeout); } static void mptcp_mp_fail_no_response(struct mptcp_sock *msk) @@ -2917,6 +2914,8 @@ static int __mptcp_init_sock(struct sock *sk) msk->first_pending = NULL; msk->rmem_fwd_alloc = 0; WRITE_ONCE(msk->rmem_released, 0); + /* MPTCP sockets do not go through tcp_init_sock(). */ + inet_csk(sk)->icsk_rto_min = TCP_RTO_MIN; msk->timer_ival = TCP_RTO_MIN; WRITE_ONCE(msk->first, NULL); @@ -2929,9 +2928,8 @@ static int __mptcp_init_sock(struct sock *sk) mptcp_pm_data_init(msk); spin_lock_init(&msk->fallback_lock); - /* re-use the csk retrans timer for MPTCP-level retrans */ - timer_setup(&msk->sk.icsk_retransmit_timer, mptcp_retransmit_timer, 0); - timer_setup(&sk->sk_timer, mptcp_tout_timer, 0); + timer_setup(&sk->mptcp_retransmit_timer, mptcp_retransmit_timer, 0); + timer_setup(&msk->sk.mptcp_tout_timer, mptcp_tout_timer, 0); return 0; } @@ -3108,7 +3106,7 @@ static void __mptcp_destroy_sock(struct sock *sk) might_sleep(); mptcp_stop_rtx_timer(sk); - sk_stop_timer(sk, &sk->sk_timer); + sk_stop_timer(sk, &inet_csk(sk)->mptcp_tout_timer); msk->pm.status = 0; sk->sk_prot->destroy(sk); diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index e835028fc4e50..cc70b15f8d692 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -697,7 +697,7 @@ static inline void mptcp_stop_tout_timer(struct sock *sk) if (!inet_csk(sk)->icsk_mtup.probe_timestamp) return; - sk_stop_timer(sk, &sk->sk_timer); + sk_stop_timer(sk, &inet_csk(sk)->mptcp_tout_timer); inet_csk(sk)->icsk_mtup.probe_timestamp = 0; } diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_tcp4.c b/tools/testing/selftests/bpf/progs/bpf_iter_tcp4.c index 92267abb462fc..be540970fcc1f 100644 --- a/tools/testing/selftests/bpf/progs/bpf_iter_tcp4.c +++ b/tools/testing/selftests/bpf/progs/bpf_iter_tcp4.c @@ -103,9 +103,9 @@ static int dump_tcp_sock(struct seq_file *seq, struct tcp_sock *tp, } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) { timer_active = 4; timer_expires = icsk->icsk_timeout; - } else if (timer_pending(&sp->sk_timer)) { + } else if (timer_pending(&icsk->icsk_keepalive_timer)) { timer_active = 2; - timer_expires = sp->sk_timer.expires; + timer_expires = icsk->icsk_keepalive_timer.expires; } else { timer_active = 0; timer_expires = bpf_jiffies64(); diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_tcp6.c b/tools/testing/selftests/bpf/progs/bpf_iter_tcp6.c index 943f7bba180e7..9f72398fc3cc3 100644 --- a/tools/testing/selftests/bpf/progs/bpf_iter_tcp6.c +++ b/tools/testing/selftests/bpf/progs/bpf_iter_tcp6.c @@ -103,9 +103,9 @@ static int dump_tcp6_sock(struct seq_file *seq, struct tcp6_sock *tp, } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) { timer_active = 4; timer_expires = icsk->icsk_timeout; - } else if (timer_pending(&sp->sk_timer)) { + } else if (timer_pending(&icsk->icsk_keepalive_timer)) { timer_active = 2; - timer_expires = sp->sk_timer.expires; + timer_expires = icsk->icsk_keepalive_timer.expires; } else { timer_active = 0; timer_expires = bpf_jiffies64(); -- 2.53.0