From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 34ADBC18E5A for ; Mon, 9 Mar 2020 11:14:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0DE9A2051A for ; Mon, 9 Mar 2020 11:14:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=cloudflare.com header.i=@cloudflare.com header.b="xFcofdtj" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726379AbgCILOT (ORCPT ); Mon, 9 Mar 2020 07:14:19 -0400 Received: from mail-wr1-f66.google.com ([209.85.221.66]:35592 "EHLO mail-wr1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726444AbgCILNN (ORCPT ); Mon, 9 Mar 2020 07:13:13 -0400 Received: by mail-wr1-f66.google.com with SMTP id r7so10552762wro.2 for ; Mon, 09 Mar 2020 04:13:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cloudflare.com; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=bXYQbvQcpVVfxQJOftOtLbw866myUq7cAFw4ms5hCzI=; b=xFcofdtjFoUwBtvCbSm2iPdfivasWRGJkR53WQmyBVLv04AbNSdHAfQQzmbA5OE88U Xt8vdTlWliLZDQUymfBQ2a3NH8if6G8qj3NeUYwyvFq4bURnnlr8GWPtcsjfqcLDcDfk UF9KyEq4LGXwQHSjcsfqCE1p9eoq5cN2bVGZI= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=bXYQbvQcpVVfxQJOftOtLbw866myUq7cAFw4ms5hCzI=; b=SL6Q/+z5jUvOeRYMsCTUlD9pzUUv++MxrtYMYJN0pwV7rvWtWRLWIi8Zvvl0od6h4V 70j117+BfhJmiUS/+D5wCzMO6o9ez4Nj2jArV1ZoF3r7ggRJpH9fGm8yzXeglKenSrBI pm17J8cA/ecaMO7y82GgBjZwe2ZzJxp7OG0sRbrAMFJR9ZU9Q2hT2coQzEKVyL6E8B3s fFtnuhgn16lty86U41Qeu39eT0fX2wM+4AryDo4H3ACfHVPifgQ8g/L+UIBTpX95EUCf AP2kcqfi8Xu+qhGXhqq/HFbRde8S0qUJrD0nU9BX9PrZ0FS2pdxvOmERzvha8xuxEJU1 4o4w== X-Gm-Message-State: ANhLgQ0N4HlzUVlcEtDx3QhxBPNfBdcYhszkU8cotOOfvEowl2zS3WXF ON/JbkK363/n9IqIJIy8+LPQMA== X-Google-Smtp-Source: ADFU+vt7604NF4aclxTrcoVHcTHYp7wb/YpuXMQtBXRHz5ddOg6tyku4iGXZWaw8xkvrhcLh77Zqpw== X-Received: by 2002:a05:6000:12c9:: with SMTP id l9mr21767238wrx.25.1583752392194; Mon, 09 Mar 2020 04:13:12 -0700 (PDT) Received: from localhost.localdomain ([2a06:98c0:1000:8250:3dcc:c1d:7f05:4873]) by smtp.gmail.com with ESMTPSA id a5sm25732846wmb.37.2020.03.09.04.13.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 09 Mar 2020 04:13:11 -0700 (PDT) From: Lorenz Bauer To: John Fastabend , Daniel Borkmann , Jakub Sitnicki , Lorenz Bauer , Eric Dumazet , "David S. Miller" , Alexey Kuznetsov , Hideaki YOSHIFUJI , Jakub Kicinski , Alexei Starovoitov Cc: kernel-team@cloudflare.com, netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH bpf-next v4 02/12] skmsg: update saved hooks only once Date: Mon, 9 Mar 2020 11:12:33 +0000 Message-Id: <20200309111243.6982-3-lmb@cloudflare.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200309111243.6982-1-lmb@cloudflare.com> References: <20200309111243.6982-1-lmb@cloudflare.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Only update psock->saved_* if psock->sk_proto has not been initialized yet. This allows us to get rid of tcp_bpf_reinit_sk_prot. Signed-off-by: Lorenz Bauer Reviewed-by: Jakub Sitnicki Acked-by: John Fastabend --- include/linux/skmsg.h | 20 ++++++++++++++++---- net/ipv4/tcp_bpf.c | 16 +--------------- 2 files changed, 17 insertions(+), 19 deletions(-) diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h index 4d3d75d63066..2be51b7a5800 100644 --- a/include/linux/skmsg.h +++ b/include/linux/skmsg.h @@ -347,11 +347,23 @@ static inline void sk_psock_update_proto(struct sock *sk, struct sk_psock *psock, struct proto *ops) { - psock->saved_unhash = sk->sk_prot->unhash; - psock->saved_close = sk->sk_prot->close; - psock->saved_write_space = sk->sk_write_space; + /* Initialize saved callbacks and original proto only once, since this + * function may be called multiple times for a psock, e.g. when + * psock->progs.msg_parser is updated. + * + * Since we've not installed the new proto, psock is not yet in use and + * we can initialize it without synchronization. + */ + if (!psock->sk_proto) { + struct proto *orig = READ_ONCE(sk->sk_prot); + + psock->saved_unhash = orig->unhash; + psock->saved_close = orig->close; + psock->saved_write_space = sk->sk_write_space; + + psock->sk_proto = orig; + } - psock->sk_proto = sk->sk_prot; /* Pairs with lockless read in sk_clone_lock() */ WRITE_ONCE(sk->sk_prot, ops); } diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c index 7d6e1b75d4d4..3327afa05c3d 100644 --- a/net/ipv4/tcp_bpf.c +++ b/net/ipv4/tcp_bpf.c @@ -637,20 +637,6 @@ static void tcp_bpf_update_sk_prot(struct sock *sk, struct sk_psock *psock) sk_psock_update_proto(sk, psock, &tcp_bpf_prots[family][config]); } -static void tcp_bpf_reinit_sk_prot(struct sock *sk, struct sk_psock *psock) -{ - int family = sk->sk_family == AF_INET6 ? TCP_BPF_IPV6 : TCP_BPF_IPV4; - int config = psock->progs.msg_parser ? TCP_BPF_TX : TCP_BPF_BASE; - - /* Reinit occurs when program types change e.g. TCP_BPF_TX is removed - * or added requiring sk_prot hook updates. We keep original saved - * hooks in this case. - * - * Pairs with lockless read in sk_clone_lock(). - */ - WRITE_ONCE(sk->sk_prot, &tcp_bpf_prots[family][config]); -} - static int tcp_bpf_assert_proto_ops(struct proto *ops) { /* In order to avoid retpoline, we make assumptions when we call @@ -670,7 +656,7 @@ void tcp_bpf_reinit(struct sock *sk) rcu_read_lock(); psock = sk_psock(sk); - tcp_bpf_reinit_sk_prot(sk, psock); + tcp_bpf_update_sk_prot(sk, psock); rcu_read_unlock(); } -- 2.20.1