From nobody Mon Sep 16 19:36:11 2024 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 B7E1B144618; Fri, 2 Feb 2024 11:40:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706874022; cv=none; b=HwB9GWf+HAfFiXQ3DcSre06Ob/gHE9TjWx5MEVHPYQvCk+wbPpQcQIsf+jVHEeMy/+1og24TKyK8XhOlzzvsVqmPVbeCWXwQ7vOO/ZvE+11ucAKkkm5sVrx8q5764zrsn84c6EoUNz5cO/9VQM4i2LeciCU829cjvJMJ/TRumy0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706874022; c=relaxed/simple; bh=jbBx8q1vG4VmSQFPNppoUAvomZ9X9DzfrEVGbLhs1RE=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=IxxKGwH8e8utSoVcNl7dwEyZw22OiOyrVJWvt2zwhja7UGBSvDfhd9C35/Ev/Ytn6GuB0AwEzeeu73SVt6LzbHvnWDVS0LwPLP01A+5cXsdTeaL4sf2lJCMOH2FwAIs+3O+7M+qTwB+x07JicIoosT/j7las/DvEqRsnyC+1GKM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NHx07HdA; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="NHx07HdA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7B01DC433C7; Fri, 2 Feb 2024 11:40:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1706874022; bh=jbBx8q1vG4VmSQFPNppoUAvomZ9X9DzfrEVGbLhs1RE=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=NHx07HdA0txkz6Kg4jcglbOKmsnMJQ58xdfY9vQ097HoD2lqfWhNU++A6LQ9hvPDr PmgKyEkHh1COawu82I/+1FfMoQcLTXslltY6yU9BEiuFjq9iSw8pCgPEeBXj9/y2g9 aAybpsJy3SlwTCCTEkH8sJwhSDIu9RVgdQ20H/YCddHdiz6zFgqU/sMGFKcXuQhaic 9TkHtwER4oQf5GoGDRPaRVP9B03kpfgMhwT56jyYZ282TJQzU9YVNfzUbtwzZwJ4/b p56c3GeDu0lydQH6LdOIt7tL5Kr+GkYscYbEenA/P7OX22/biLGCqvOEW772fha6wA 2HzjsbtrPD0yA== From: "Matthieu Baerts (NGI0)" Date: Fri, 02 Feb 2024 12:40:08 +0100 Subject: [PATCH net-next 2/5] mptcp: annotate lockless access for the tx path Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20240202-upstream-net-next-20240202-mptcp-annotate-lockless-access-v1-2-031d6680afdc@kernel.org> References: <20240202-upstream-net-next-20240202-mptcp-annotate-lockless-access-v1-0-031d6680afdc@kernel.org> In-Reply-To: <20240202-upstream-net-next-20240202-mptcp-annotate-lockless-access-v1-0-031d6680afdc@kernel.org> To: mptcp@lists.linux.dev, Mat Martineau , Geliang Tang , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "Matthieu Baerts (NGI0)" X-Mailer: b4 0.12.4 X-Developer-Signature: v=1; a=openpgp-sha256; l=3573; i=matttbe@kernel.org; h=from:subject:message-id; bh=7J0ps97A16g4/waL3hRAHqtfG/mCa7C1N2tO1Q3wljs=; b=owEBbQKS/ZANAwAIAfa3gk9CaaBzAcsmYgBlvNSeEHAGjdHYf9+bhXUw0e25/bnvtwTgQPzCO hD8NwuWSW+JAjMEAAEIAB0WIQToy4X3aHcFem4n93r2t4JPQmmgcwUCZbzUngAKCRD2t4JPQmmg c2nrD/4rw4BSU4iHidYCavNrIGDXx87gVG23+vvfoUKu8HzUhssJai6lFM7HKzLL6nBbp0P/AYf Kk9XjZ/I9jq+gq3SmH3Unbdbb2a4CcQC1UmWy6Zm0tmmsj9tx/wWSSxCLAMxYYqJC1ay8rnb53N a2x/7hr6aoND1O/tqqskqXA50X/flbmCSUAneFYNAN4X1YENXB3pkIB/guybBgS2uE4fN9kdXON lP2zfKajD75+Oy2PXA2YM4Icswx7skiaaTPlv02ipfRoX7Uu3wRqDxuCm0DKsU+sIXHBOfDr2wc gRZcxRo7jE46xw3152JW6kjwVPf+D+pxjOas4PThmZoXwzo7QCmDCdVsk/1KC0u0AdCDJEMb/9A QvrkvvlCtek1dw2G/ywdxq2ZhoYf9YUO7IYyLZnFl/OzlBdwNLq3jPlZQ5Ew4AR/xJLXVNmNj6A ainP8gh97rpFenzS7OFAbkb1TyTne5KI9GhuO8YAbQ1TQgfDTXrTBsbx589TPeI03imb0Ycsh6f TtoYh6cjsdEK1vhkeL5bSrebmIv/J9joQ2xT0aharoSYV8wbIsfJ//TCbokpZh7t+aph70LuSqU OOOwywjBp3QGFl73cCGinUkAzWJ5qf1udzZW/XZseXb2D9JVRWqsLkjrrDH4LzF0aGeHdd3zIOk IG/KyuQMKV9qCjQ== X-Developer-Key: i=matttbe@kernel.org; a=openpgp; fpr=E8CB85F76877057A6E27F77AF6B7824F4269A073 From: Paolo Abeni The mptcp-level TX path info (write_seq, bytes_sent, snd_nxt) are under the msk socket lock protection, and are accessed lockless in a few spots. Always mark the write operations with WRITE_ONCE, read operations outside the lock with READ_ONCE and drop the annotation for read under such lock. To simplify the annotations move mptcp_pending_data_fin_ack() from __mptcp_data_acked() to __mptcp_clean_una(), under the msk socket lock, where such call would belong. Signed-off-by: Paolo Abeni Reviewed-by: Mat Martineau Signed-off-by: Matthieu Baerts (NGI0) --- net/mptcp/options.c | 2 +- net/mptcp/protocol.c | 15 +++++++-------- net/mptcp/protocol.h | 2 +- 3 files changed, 9 insertions(+), 10 deletions(-) diff --git a/net/mptcp/options.c b/net/mptcp/options.c index 5e2b130d8680..9b31a0a06265 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -1060,7 +1060,7 @@ static void ack_update_msk(struct mptcp_sock *msk, msk->wnd_end =3D new_wnd_end; =20 /* this assumes mptcp_incoming_options() is invoked after tcp_ack() */ - if (after64(msk->wnd_end, READ_ONCE(msk->snd_nxt))) + if (after64(msk->wnd_end, snd_nxt)) __mptcp_check_push(sk, ssk); =20 if (after64(new_snd_una, old_snd_una)) { diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 874f019c5093..b1c24ac3630f 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1033,13 +1033,15 @@ static void __mptcp_clean_una(struct sock *sk) msk->recovery =3D false; =20 out: - if (snd_una =3D=3D READ_ONCE(msk->snd_nxt) && - snd_una =3D=3D READ_ONCE(msk->write_seq)) { + if (snd_una =3D=3D msk->snd_nxt && snd_una =3D=3D msk->write_seq) { if (mptcp_rtx_timer_pending(sk) && !mptcp_data_fin_enabled(msk)) mptcp_stop_rtx_timer(sk); } else { mptcp_reset_rtx_timer(sk); } + + if (mptcp_pending_data_fin_ack(sk)) + mptcp_schedule_work(sk); } =20 static void __mptcp_clean_una_wakeup(struct sock *sk) @@ -1499,7 +1501,7 @@ static void mptcp_update_post_push(struct mptcp_sock = *msk, */ if (likely(after64(snd_nxt_new, msk->snd_nxt))) { msk->bytes_sent +=3D snd_nxt_new - msk->snd_nxt; - msk->snd_nxt =3D snd_nxt_new; + WRITE_ONCE(msk->snd_nxt, snd_nxt_new); } } =20 @@ -3200,8 +3202,8 @@ struct sock *mptcp_sk_clone_init(const struct sock *s= k, if (mp_opt->suboptions & OPTION_MPTCP_CSUMREQD) WRITE_ONCE(msk->csum_enabled, true); =20 - msk->write_seq =3D subflow_req->idsn + 1; - msk->snd_nxt =3D msk->write_seq; + WRITE_ONCE(msk->write_seq, subflow_req->idsn + 1); + WRITE_ONCE(msk->snd_nxt, msk->write_seq); msk->snd_una =3D msk->write_seq; msk->wnd_end =3D msk->snd_nxt + req->rsk_rcv_wnd; msk->setsockopt_seq =3D mptcp_sk(sk)->setsockopt_seq; @@ -3303,9 +3305,6 @@ void __mptcp_data_acked(struct sock *sk) __mptcp_clean_una(sk); else __set_bit(MPTCP_CLEAN_UNA, &mptcp_sk(sk)->cb_flags); - - if (mptcp_pending_data_fin_ack(sk)) - mptcp_schedule_work(sk); } =20 void __mptcp_check_push(struct sock *sk, struct sock *ssk) diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 13b8cf8ec704..421dede93e2b 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -402,7 +402,7 @@ static inline struct mptcp_data_frag *mptcp_rtx_head(st= ruct sock *sk) { struct mptcp_sock *msk =3D mptcp_sk(sk); =20 - if (msk->snd_una =3D=3D READ_ONCE(msk->snd_nxt)) + if (msk->snd_una =3D=3D msk->snd_nxt) return NULL; =20 return list_first_entry_or_null(&msk->rtx_queue, struct mptcp_data_frag, = list); --=20 2.43.0