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=-11.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 8F3C7C33CA2 for ; Thu, 9 Jan 2020 10:33:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5D2DD2072A for ; Thu, 9 Jan 2020 10:33:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=cloudflare.com header.i=@cloudflare.com header.b="gOg28xh7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728448AbgAIKdf (ORCPT ); Thu, 9 Jan 2020 05:33:35 -0500 Received: from mail-wr1-f67.google.com ([209.85.221.67]:44225 "EHLO mail-wr1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729165AbgAIKdf (ORCPT ); Thu, 9 Jan 2020 05:33:35 -0500 Received: by mail-wr1-f67.google.com with SMTP id q10so6774684wrm.11 for ; Thu, 09 Jan 2020 02:33:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cloudflare.com; s=google; h=references:user-agent:from:to:cc:subject:in-reply-to:date :message-id:mime-version; bh=PQ++vjBtZFpbZ5vhUNmFbh7+x0gOXpjlJ1L44U/rr0I=; b=gOg28xh773Kv91RO5DuJ6yDTe8iX2YIwAroGOqjURQ7Qt19q++Udqx+3ZpUgbuA+E1 huZQr3S/YGFe27gvto3qmN43tbqHS3Z1rj9e6X1ajdK7o2QF6CSBlXliAntK1NgEYbPj iPH/WV9alqPggIZsR8+DAlZZ/PwPKu9ZvdNFE= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:references:user-agent:from:to:cc:subject :in-reply-to:date:message-id:mime-version; bh=PQ++vjBtZFpbZ5vhUNmFbh7+x0gOXpjlJ1L44U/rr0I=; b=nu/glAy1Ko1ETSgkhyjsD+vFMF0p09oMR26T/kpBVnXnDwETb7KsgKmmIhePsKOvMf ekCqeal/UWL1IrxNbs9kThdjPZmS/X3JyixVh+juWue4NqLFJfJZ5yWIXDnEEO6aoPsR ZJzxwxjqWgCxeHX46wAVrjlwpZ4JXMHDZK0d4SV0KOoRbXBu494KKkc8x1DzlXOCVze2 R9DuV9STVx6xtpVPo8n5LySIYMMlN9j+vZCMLXbIIdoTUK9XiVXhL3oFLNXJgo4Gyy9m JkbwU+rCaAg7DUZcJyu51lCYSkkgTpWbL39nJ32zInOybePWvilAfNo/Hjs8ImdhvRxj NSOQ== X-Gm-Message-State: APjAAAXjjgGM6PLOFKcf1LZgrnTC04NiWeNCUGr4jVXj1GLXbdvQJR5U b2i8kQ2+ShH686ClH9kJiMpZgw== X-Google-Smtp-Source: APXvYqxvDTJO+DGXoKt4xOvaTcNgga5xQJrpfeuS9ODtTpXcNuAYW8/QTjOvTEZ1s2Wc1mS7KQKgUA== X-Received: by 2002:adf:ea4e:: with SMTP id j14mr10354600wrn.101.1578566012763; Thu, 09 Jan 2020 02:33:32 -0800 (PST) Received: from cloudflare.com ([176.221.114.230]) by smtp.gmail.com with ESMTPSA id f1sm7607039wru.6.2020.01.09.02.33.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 09 Jan 2020 02:33:32 -0800 (PST) References: <157851776348.1732.12600714815781177085.stgit@ubuntu3-kvm2> <157851808101.1732.11616068811837364406.stgit@ubuntu3-kvm2> User-agent: mu4e 1.1.0; emacs 26.3 From: Jakub Sitnicki To: John Fastabend Cc: bpf@vger.kernel.org, netdev@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net Subject: Re: [bpf PATCH 3/9] bpf: sockmap/tls, push write_space updates through ulp updates In-reply-to: <157851808101.1732.11616068811837364406.stgit@ubuntu3-kvm2> Date: Thu, 09 Jan 2020 11:33:31 +0100 Message-ID: <87tv54syv8.fsf@cloudflare.com> MIME-Version: 1.0 Content-Type: text/plain Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Wed, Jan 08, 2020 at 10:14 PM CET, John Fastabend wrote: > When sockmap sock with TLS enabled is removed we cleanup bpf/psock state > and call tcp_update_ulp() to push updates to TLS ULP on top. However, we > don't push the write_space callback up and instead simply overwrite the > op with the psock stored previous op. This may or may not be correct so > to ensure we don't overwrite the TLS write space hook pass this field to > the ULP and have it fixup the ctx. > > This completes a previous fix that pushed the ops through to the ULP > but at the time missed doing this for write_space, presumably because > write_space TLS hook was added around the same time. > > Fixes: 95fa145479fbc ("bpf: sockmap/tls, close can race with map free") > Signed-off-by: John Fastabend > --- > include/linux/skmsg.h | 12 ++++++++---- > include/net/tcp.h | 6 ++++-- > net/ipv4/tcp_ulp.c | 6 ++++-- > net/tls/tls_main.c | 10 +++++++--- > 4 files changed, 23 insertions(+), 11 deletions(-) > > diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h > index b6afe01f8592..14d61bba0b79 100644 > --- a/include/linux/skmsg.h > +++ b/include/linux/skmsg.h > @@ -359,17 +359,21 @@ static inline void sk_psock_restore_proto(struct sock *sk, > struct sk_psock *psock) > { > sk->sk_prot->unhash = psock->saved_unhash; > - sk->sk_write_space = psock->saved_write_space; > > if (psock->sk_proto) { > struct inet_connection_sock *icsk = inet_csk(sk); > bool has_ulp = !!icsk->icsk_ulp_data; > > - if (has_ulp) > - tcp_update_ulp(sk, psock->sk_proto); > - else > + if (has_ulp) { > + tcp_update_ulp(sk, psock->sk_proto, > + psock->saved_write_space); > + } else { > sk->sk_prot = psock->sk_proto; > + sk->sk_write_space = psock->saved_write_space; > + } I'm wondering if we need the above fallback branch for no-ULP case? tcp_update_ulp repeats the ULP check and has the same fallback. Perhaps it can be reduced to: if (psock->sk_proto) { tcp_update_ulp(sk, psock->sk_proto, psock->saved_write_space); psock->sk_proto = NULL; } else { sk->sk_write_space = psock->saved_write_space; } Then there's the question if it's okay to leave psock->sk_proto set and potentially restore it more than once? Reading tls_update, the only user ULP 'update' callback, it looks fine. Can sk_psock_restore_proto be as simple as: static inline void sk_psock_restore_proto(struct sock *sk, struct sk_psock *psock) { tcp_update_ulp(sk, psock->sk_proto, psock->saved_write_space); } ... or am I missing something? Asking becuase I have a patch [0] like this in the queue and haven't seen issues with it during testing. -jkbs [0] https://github.com/jsitnicki/linux/commit/2d2152593c8e6c5f38548796501a81a6ba20b6dc > psock->sk_proto = NULL; > + } else { > + sk->sk_write_space = psock->saved_write_space; > } > } > > diff --git a/include/net/tcp.h b/include/net/tcp.h > index e460ea7f767b..e6f48384dc71 100644 > --- a/include/net/tcp.h > +++ b/include/net/tcp.h > @@ -2147,7 +2147,8 @@ struct tcp_ulp_ops { > /* initialize ulp */ > int (*init)(struct sock *sk); > /* update ulp */ > - void (*update)(struct sock *sk, struct proto *p); > + void (*update)(struct sock *sk, struct proto *p, > + void (*write_space)(struct sock *sk)); > /* cleanup ulp */ > void (*release)(struct sock *sk); > /* diagnostic */ > @@ -2162,7 +2163,8 @@ void tcp_unregister_ulp(struct tcp_ulp_ops *type); > int tcp_set_ulp(struct sock *sk, const char *name); > void tcp_get_available_ulp(char *buf, size_t len); > void tcp_cleanup_ulp(struct sock *sk); > -void tcp_update_ulp(struct sock *sk, struct proto *p); > +void tcp_update_ulp(struct sock *sk, struct proto *p, > + void (*write_space)(struct sock *sk)); > > #define MODULE_ALIAS_TCP_ULP(name) \ > __MODULE_INFO(alias, alias_userspace, name); \ > diff --git a/net/ipv4/tcp_ulp.c b/net/ipv4/tcp_ulp.c > index 12ab5db2b71c..38d3ad141161 100644 > --- a/net/ipv4/tcp_ulp.c > +++ b/net/ipv4/tcp_ulp.c > @@ -99,17 +99,19 @@ void tcp_get_available_ulp(char *buf, size_t maxlen) > rcu_read_unlock(); > } > > -void tcp_update_ulp(struct sock *sk, struct proto *proto) > +void tcp_update_ulp(struct sock *sk, struct proto *proto, > + void (*write_space)(struct sock *sk)) > { > struct inet_connection_sock *icsk = inet_csk(sk); > > if (!icsk->icsk_ulp_ops) { > + sk->sk_write_space = write_space; > sk->sk_prot = proto; > return; > } > > if (icsk->icsk_ulp_ops->update) > - icsk->icsk_ulp_ops->update(sk, proto); > + icsk->icsk_ulp_ops->update(sk, proto, write_space); > } > > void tcp_cleanup_ulp(struct sock *sk) > diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c > index dac24c7aa7d4..94774c0e5ff3 100644 > --- a/net/tls/tls_main.c > +++ b/net/tls/tls_main.c > @@ -732,15 +732,19 @@ static int tls_init(struct sock *sk) > return rc; > } > > -static void tls_update(struct sock *sk, struct proto *p) > +static void tls_update(struct sock *sk, struct proto *p, > + void (*write_space)(struct sock *sk)) > { > struct tls_context *ctx; > > ctx = tls_get_ctx(sk); > - if (likely(ctx)) > + if (likely(ctx)) { > + ctx->sk_write_space = write_space; > ctx->sk_proto = p; > - else > + } else { > sk->sk_prot = p; > + sk->sk_write_space = write_space; > + } > } > > static int tls_get_info(const struct sock *sk, struct sk_buff *skb)