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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D521EC4321E for ; Tue, 29 Nov 2022 01:01:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234619AbiK2BBP (ORCPT ); Mon, 28 Nov 2022 20:01:15 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37914 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234672AbiK2BBL (ORCPT ); Mon, 28 Nov 2022 20:01:11 -0500 Received: from smtp-fw-80007.amazon.com (smtp-fw-80007.amazon.com [99.78.197.218]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A7C773E0A6; Mon, 28 Nov 2022 17:01:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1669683671; x=1701219671; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=TnLUlshqejAasTVyid01sMRX0wFcafdFFs3w3Ws5T8g=; b=uqhDYOlmsOFprkhxETfTG5xkWQwdUVxuimeAeusXuxN1GSChNpDo7Gxi uktHju+dXzL7k2RnR/a3YcK63hKNnAljaHIs5yXhW+VDUx9fsiB6PsX8T Z+7oLpIb+skyfw/QkUp63LpXVEdaYhMtPYUWicVdWmbS0uvPiCeq7uVCE 8=; X-IronPort-AV: E=Sophos;i="5.96,201,1665446400"; d="scan'208";a="155736595" Received: from pdx4-co-svc-p1-lb2-vlan3.amazon.com (HELO email-inbound-relay-pdx-2a-m6i4x-21d8d9f4.us-west-2.amazon.com) ([10.25.36.214]) by smtp-border-fw-80007.pdx80.corp.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Nov 2022 01:01:09 +0000 Received: from EX13MTAUWC001.ant.amazon.com (pdx1-ws-svc-p6-lb9-vlan2.pdx.amazon.com [10.236.137.194]) by email-inbound-relay-pdx-2a-m6i4x-21d8d9f4.us-west-2.amazon.com (Postfix) with ESMTPS id 86F1781BCC; Tue, 29 Nov 2022 01:01:08 +0000 (UTC) Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX13MTAUWC001.ant.amazon.com (10.43.162.135) with Microsoft SMTP Server (TLS) id 15.0.1497.42; Tue, 29 Nov 2022 01:01:08 +0000 Received: from 88665a182662.ant.amazon.com (10.43.162.134) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1118.20; Tue, 29 Nov 2022 01:01:04 +0000 From: Kuniyuki Iwashima To: CC: , , , , , , , , , Subject: Re: [PATCH RESEND net-next] tcp: socket-specific version of WARN_ON_ONCE() Date: Tue, 29 Nov 2022 10:00:55 +0900 Message-ID: <20221129010055.75780-1-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20221124112229.789975-1-leitao@debian.org> References: <20221124112229.789975-1-leitao@debian.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.43.162.134] X-ClientProxiedBy: EX13D24UWB001.ant.amazon.com (10.43.161.93) To EX19D004ANA001.ant.amazon.com (10.37.240.138) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Breno Leitao Date: Thu, 24 Nov 2022 03:22:29 -0800 > There are cases where we need information about the socket during a > warning, so, it could help us to find bugs that happens and do not have > an easy repro. > > This diff creates a TCP socket-specific version of WARN_ON_ONCE(), which > dumps more information about the TCP socket. > > This new warning is not only useful to give more insight about kernel bugs, but, > it is also helpful to expose information that might be coming from buggy > BPF applications, such as BPF applications that sets invalid > tcp_sock->snd_cwnd values. Have you finally found a root cause on BPF or TCP side ? > Signed-off-by: Breno Leitao > --- > include/net/tcp.h | 3 ++- > include/net/tcp_debug.h | 10 ++++++++++ > net/ipv4/tcp.c | 30 ++++++++++++++++++++++++++++++ > 3 files changed, 42 insertions(+), 1 deletion(-) > create mode 100644 include/net/tcp_debug.h > > diff --git a/include/net/tcp.h b/include/net/tcp.h > index 14d45661a84d..e490af8e6fdc 100644 > --- a/include/net/tcp.h > +++ b/include/net/tcp.h > @@ -40,6 +40,7 @@ > #include > #include > #include > +#include > > #include > #include > @@ -1229,7 +1230,7 @@ static inline u32 tcp_snd_cwnd(const struct tcp_sock *tp) > > static inline void tcp_snd_cwnd_set(struct tcp_sock *tp, u32 val) > { > - WARN_ON_ONCE((int)val <= 0); > + TCP_SOCK_WARN_ON_ONCE(tp, (int)val <= 0); > tp->snd_cwnd = val; > } > > diff --git a/include/net/tcp_debug.h b/include/net/tcp_debug.h > new file mode 100644 > index 000000000000..50e96d87d335 > --- /dev/null > +++ b/include/net/tcp_debug.h > @@ -0,0 +1,10 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +#ifndef _LINUX_TCP_DEBUG_H > +#define _LINUX_TCP_DEBUG_H > + > +void tcp_sock_warn(const struct tcp_sock *tp); > + > +#define TCP_SOCK_WARN_ON_ONCE(tcp_sock, condition) \ > + DO_ONCE_LITE_IF(condition, tcp_sock_warn, tcp_sock) > + > +#endif /* _LINUX_TCP_DEBUG_H */ > diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c > index 54836a6b81d6..dd682f60c7cb 100644 > --- a/net/ipv4/tcp.c > +++ b/net/ipv4/tcp.c > @@ -4705,6 +4705,36 @@ int tcp_abort(struct sock *sk, int err) > } > EXPORT_SYMBOL_GPL(tcp_abort); > > +void tcp_sock_warn(const struct tcp_sock *tp) > +{ > + const struct sock *sk = (const struct sock *)tp; > + struct inet_sock *inet = inet_sk(sk); > + struct inet_connection_sock *icsk = inet_csk(sk); > + > + WARN_ON(1); > + > + if (!tp) Is this needed ? > + return; > + > + pr_warn("Socket Info: family=%u state=%d sport=%u dport=%u ccname=%s cwnd=%u", > + sk->sk_family, sk->sk_state, ntohs(inet->inet_sport), > + ntohs(inet->inet_dport), icsk->icsk_ca_ops->name, tcp_snd_cwnd(tp)); > + > + switch (sk->sk_family) { > + case AF_INET: > + pr_warn("saddr=%pI4 daddr=%pI4", &inet->inet_saddr, > + &inet->inet_daddr); As with tcp_syn_flood_action(), [address]:port format is easy to read and consistent in kernel ? > + break; > +#if IS_ENABLED(CONFIG_IPV6) > + case AF_INET6: > + pr_warn("saddr=%pI6 daddr=%pI6", &sk->sk_v6_rcv_saddr, > + &sk->sk_v6_daddr); > + break; > +#endif > + } > +} > +EXPORT_SYMBOL_GPL(tcp_sock_warn); > + > extern struct tcp_congestion_ops tcp_reno; > > static __initdata unsigned long thash_entries; > -- > 2.30.2