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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 3CDDAC48BC2 for ; Wed, 23 Jun 2021 16:53:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2585261166 for ; Wed, 23 Jun 2021 16:53:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229873AbhFWQzt (ORCPT ); Wed, 23 Jun 2021 12:55:49 -0400 Received: from jabberwock.ucw.cz ([46.255.230.98]:42480 "EHLO jabberwock.ucw.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229523AbhFWQzq (ORCPT ); Wed, 23 Jun 2021 12:55:46 -0400 Received: by jabberwock.ucw.cz (Postfix, from userid 1017) id D71601C0B76; Wed, 23 Jun 2021 18:53:27 +0200 (CEST) Date: Wed, 23 Jun 2021 18:53:27 +0200 From: Pavel Machek To: Paolo Abeni Cc: Greg Kroah-Hartman , linux-kernel@vger.kernel.org, stable@vger.kernel.org, Mat Martineau , "David S. Miller" , Sasha Levin Subject: Re: [PATCH 5.10 038/146] mptcp: do not warn on bad input from the network Message-ID: <20210623165327.GA4150@amd> References: <20210621154911.244649123@linuxfoundation.org> <20210621154912.589676201@linuxfoundation.org> <20210623142235.GA27348@amd> <254a0b83518083416abdae4cd27659bc10760773.camel@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="W/nzBZO5zC0uMSeA" Content-Disposition: inline In-Reply-To: <254a0b83518083416abdae4cd27659bc10760773.camel@redhat.com> User-Agent: Mutt/1.5.23 (2014-03-12) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --W/nzBZO5zC0uMSeA Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! > > > From: Paolo Abeni > > >=20 > > > [ Upstream commit 61e710227e97172355d5f150d5c78c64175d9fb2 ] > > >=20 > > > warn_bad_map() produces a kernel WARN on bad input coming > > > from the network. Use pr_debug() to avoid spamming the system > > > log. > >=20 > > So... we switched from WARN _ONCE_ to pr_debug, as many times as we > > detect the problem. > >=20 > > Should this be pr_debug_once? >=20 > Thank you for double checking this! >=20 > In the MPTCP code, we use pr_debug() statements as a debug tool, e.g. > when enabled, it could print per-packet info with no restriction.=20 >=20 > There are (a few) similar use in the plain TCP code. >=20 > pr_debug() is not supposed to be enabled on any production system, > while the WARN_ONCE could trigger automated tools for irrelevant > network noise. Correct me if I'm wrong, but I believe pr_debug will result in messages being stored in the dmesg buffer, even on production systems. Best regards, Pavel --=20 http://www.livejournal.com/~pavelmachek --W/nzBZO5zC0uMSeA Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAmDTZwYACgkQMOfwapXb+vLbUACfTkpdQc/zNyx4Zx9cOFG2kmYU 7MYAnjvIgmPHboyiCqxdaPK0XXhSx4I2 =y0g6 -----END PGP SIGNATURE----- --W/nzBZO5zC0uMSeA--