From nobody Fri Oct 18 06:21:56 2024 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 D1E371CD23 for ; Tue, 16 Jan 2024 18:16:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705428988; cv=none; b=pHTpc8t6QOw2kL5xNp9acQ2/rdiO1tO6KThMAVcY8OhMtPbd7qKylW1VG9MmLTMRmYPaOqpotobYKEL9gFMGmGsChko+TRgPsKyp1ZriYMAND3CBD5JWnaEv+wCl7KprqUk7Op4svaK57VWQJKPbJ86rpJmwOP6Z1d8lRLpkC4A= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705428988; c=relaxed/simple; bh=sX5FbE8Pbm0Ynp7114CU3ikFv9zcrotQgGAx37goFpg=; h=DKIM-Signature:Received:X-MC-Unique:Received:Received:From:To: Subject:Date:Message-ID:In-Reply-To:References:MIME-Version: X-Scanned-By:X-Mimecast-Spam-Score:X-Mimecast-Originator: Content-Transfer-Encoding:Content-Type; b=uOdhb02K7W6ePf/Arg3QsV4mBWsbQnc0QUTW9LKQZMaKDW/nPpIXSTf5LDE4uWc3ch31cOvuKWrKIVFRdMRdYGkQQDfxJEWVgpM3p7PUTIFFYQtHp6X3t0lqP/10K+e35+jRKOa5whivzkSajHBGfqFT6pOWgVcNyNc9rZ6WXAg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=bLsOvrxJ; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="bLsOvrxJ" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1705428985; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=FT09gDIvluUFxbY3kzwRCZoIX35ySbqgC6jLcmu8Qv8=; b=bLsOvrxJGEDuBiOzEI1NOuw1lvoQyiURKBrc5eiJeFtae4i754H4jt4VvcaWetlwoCL7ci Go0GqP2pFq/PPNb4ARID4DcWorCcPUaZoLzgCyyWCWvd16siM6V42YcDsplvDOcYAWFcAw /5VzaZAkVWHAXCP6pwagsuPmbIgYf2k= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-159-tzQnuWBbNSulgndgxCAovA-1; Tue, 16 Jan 2024 13:16:24 -0500 X-MC-Unique: tzQnuWBbNSulgndgxCAovA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 173773869142 for ; Tue, 16 Jan 2024 18:16:24 +0000 (UTC) Received: from gerbillo.redhat.com (unknown [10.45.225.11]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9AF101121306 for ; Tue, 16 Jan 2024 18:16:23 +0000 (UTC) From: Paolo Abeni To: mptcp@lists.linux.dev Subject: [PATCH mptcp-next 2/5] mptcp: annotate lockless access for the tx path Date: Tue, 16 Jan 2024 19:16:11 +0100 Message-ID: <92930a7b962611507f4bb87671d97f526ece5952.1705427537.git.pabeni@redhat.com> In-Reply-To: References: Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.3 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8"; x-default="true" 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 --- net/mptcp/options.c | 2 +- net/mptcp/protocol.c | 14 ++++++-------- net/mptcp/protocol.h | 2 +- 3 files changed, 8 insertions(+), 10 deletions(-) diff --git a/net/mptcp/options.c b/net/mptcp/options.c index cebbd0bc32aa..51b00d7e7c89 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -1061,7 +1061,7 @@ 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 9ad672a10c11..679d4576d2c1 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1033,13 +1033,14 @@ 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 +1500,7 @@ 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 @@ -3210,8 +3211,8 @@ 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; @@ -3316,9 +3317,6 @@ 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 3af85643328e..d05ec76dd7c2 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