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 F3C364FDE5A for ; Thu, 17 Sep 2026 12:49:08 +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=1789649362; cv=none; b=Nlf71mzgdfzv9jKBIGA3kpfr1gju+YvaObe480E5c+cMuI3D1YMtak3q+r0nZtlNDobNuvFIuKV0pXydqUvByHv1A1DQeN5lH5cIlwWGQvICYZAhfp6v6TiZJUGOJupyDoDO1FQJdnWMMMNT1sdt2RqcXG2i4sfy5gXmsZOxQW0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789649362; c=relaxed/simple; bh=oARIR2mQjj+zSEjei4mMgNd9O103Dnooxe/FkE1qC9c=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=CtemsG3qdaWyD4JOajeMLHeGtAZBCU1OGkuveVWjOPqFWYcREhIFmysV+vod7G20ykKqHKFdwvRcgPjkD/9xQJSxBKszj6qdjaZcoKqiWSLO86HT5tScBmOGpC7cCch+D3kZuc2tTub2Txjj3daNZ3rc/nRsyDXaycomjVsLDgM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=dPr/1lqE; 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="dPr/1lqE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7A3601F0089B; Thu, 17 Sep 2026 12:49:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789649345; bh=OSC72dXnWkQwXmQhWGmjmLR5POUgcl4Gxio2zJivTw4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=dPr/1lqEhckyNiF/Qaquobr1oNxvwSLofoGpB5RvHDfH9QkfihKrZydD2NNfiujrt zRWsUweaKV2Kkp4uMfm4+NTjrjiBc9DwiUaliyWN7nAZpOzuxYrJH2ZmX8EvwacXc4 Bb0aOefc3HXAProbSToaSfmhjh9XByBRz/tLonO7i1m3rU61n5xOv93NTTh3CwEe5f moWDmmr0AM11Cm4FYxfQx2FdooNqN7KmCXRs8Whzr/QNMcEPQZgiSmP27uKHqqBNCD rvm/wi27Jn58E3rAy5e8664bwqLRg6OSegxG1lfjXj6OHLgU3piUXcN7v0tru9Aah6 OGmaW5GZmzcqw== From: Sasha Levin To: stable@vger.kernel.org Cc: Eric Dumazet , Kuniyuki Iwashima , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.6.y 1/2] tcp: introduce icsk->icsk_keepalive_timer Date: Thu, 17 Sep 2026 08:49:02 -0400 Message-ID: <20260917124903.223926-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026091621-borough-happiness-9e59@gregkh> References: <2026091621-borough-happiness-9e59@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 adaptation for Linux 6.6 and target 85c580b0d859: Keep icsk_timeout and the existing inet_csk keepalive helpers, updating those helpers rather than introducing the newer TCP-specific functions. Use from_timer() and update the DCCP callback to match the shared timer initializer. Drop the cacheline documentation hunk: that file does not exist in this branch. Provide the target's sk->mptcp_retransmit_timer alias and move all MPTCP retransmit timer operations to that storage, now freed by moving the timeout timer. TCP retransmit timers retain their stable-tree layout. Initialize MPTCP's icsk_rto_min to TCP_RTO_MIN so the target's disconnect reset has a valid value. Move the existing disconnect close-event notification into the existing mptcp_pm_connection_closed() function and call it from disconnect, matching the target's patch context without changing event delivery. No functions are added. These adaptations allow the target patch to apply unchanged. [ sashal: Reduced backport -- upstream 08dfe370239e5 touches 11 file(s), this backport carries 13. 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/pm.c | 3 ++ net/mptcp/protocol.c | 32 ++++++++----------- net/mptcp/protocol.h | 2 +- .../selftests/bpf/progs/bpf_iter_tcp4.c | 4 +-- .../selftests/bpf/progs/bpf_iter_tcp6.c | 4 +-- 13 files changed, 53 insertions(+), 40 deletions(-) diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h index 4ed883cad65a0..0a33e7cdcc8ba 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 c1f129a532b20..f1a5c61d6acf9 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 @@ -462,7 +463,10 @@ 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 b3255e87cc7e1..b4fb33eb02fb0 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 530d495ff7d28..c2883a4f25fc9 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -752,7 +752,7 @@ 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); @@ -765,7 +765,7 @@ 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); @@ -780,18 +780,18 @@ 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 5d09ab3ed735e..2128f28e8248d 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 638303d6691eb..b85db4825178b 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -2713,9 +2713,9 @@ 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 b65cd417b0f7c..1205fcb138af5 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -739,8 +739,9 @@ 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 f13fdd1214aaa..8b772983e47b9 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -1990,9 +1990,9 @@ 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/pm.c b/net/mptcp/pm.c index 0d21f4e693908..ee2ef0171969c 100644 --- a/net/mptcp/pm.c +++ b/net/mptcp/pm.c @@ -155,6 +155,9 @@ void mptcp_pm_fully_established(struct mptcp_sock *msk, const struct sock *ssk) void mptcp_pm_connection_closed(struct mptcp_sock *msk) { pr_debug("msk=%p\n", msk); + + if (msk->token) + mptcp_event(MPTCP_EVENT_CLOSED, msk, NULL, GFP_KERNEL); } void mptcp_pm_subflow_established(struct mptcp_sock *msk) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 127438ef120e6..eb5ade30f1a31 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -416,9 +416,7 @@ static bool __mptcp_move_skb(struct sock *sk, struct sk_buff *skb) 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; } @@ -971,12 +969,11 @@ 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 */ @@ -984,7 +981,7 @@ 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) @@ -2353,9 +2350,7 @@ 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); @@ -2373,7 +2368,9 @@ 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); @@ -2816,7 +2813,7 @@ 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) @@ -2931,7 +2928,8 @@ static void __mptcp_init_sock(struct sock *sk) msk->first_pending = NULL; msk->rmem_fwd_alloc = 0; WRITE_ONCE(msk->rmem_released, 0); - msk->timer_ival = TCP_RTO_MIN; + msk->sk.icsk_rto_min = TCP_RTO_MIN; + msk->timer_ival = msk->sk.icsk_rto_min; msk->scaling_ratio = TCP_DEFAULT_SCALING_RATIO; WRITE_ONCE(msk->first, NULL); @@ -2945,9 +2943,8 @@ static void __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); } static void mptcp_ca_reset(struct sock *sk) @@ -3148,7 +3145,7 @@ 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; mptcp_release_sched(msk); @@ -3320,8 +3317,7 @@ static int mptcp_disconnect(struct sock *sk, int flags) mptcp_stop_rtx_timer(sk); mptcp_stop_tout_timer(sk); - if (msk->token) - mptcp_event(MPTCP_EVENT_CLOSED, msk, NULL, GFP_KERNEL); + mptcp_pm_connection_closed(msk); /* msk->subflow is still intact, the following will not free the first * subflow diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index af00d64e61f4b..6d390269da5c5 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -764,7 +764,7 @@ 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