From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-5.8 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id 613607D072 for ; Wed, 23 May 2018 11:36:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932550AbeEWLfA (ORCPT ); Wed, 23 May 2018 07:35:00 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:36664 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932529AbeEWLfA (ORCPT ); Wed, 23 May 2018 07:35:00 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 78D5087ABE; Wed, 23 May 2018 11:34:59 +0000 (UTC) Received: from asgard.redhat.com (ovpn-200-41.brq.redhat.com [10.40.200.41]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 6919210C5635; Wed, 23 May 2018 11:34:54 +0000 (UTC) Date: Wed, 23 May 2018 13:35:47 +0200 From: Eugene Syromiatnikov To: Alexei Starovoitov Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, Kees Cook , Kai-Heng Feng , Daniel Borkmann , Alexei Starovoitov , Jonathan Corbet , Jiri Olsa , Jesper Dangaard Brouer Subject: Re: [PATCH 0/3] bpf: add boot parameters for sysctl knobs Message-ID: <20180523113542.GD3888@asgard.redhat.com> References: <20180521122923.GA15717@asgard.redhat.com> <20180521185811.2r6372timh5rfs5n@ast-mbp.dhcp.thefacebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180521185811.2r6372timh5rfs5n@ast-mbp.dhcp.thefacebook.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Wed, 23 May 2018 11:34:59 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Wed, 23 May 2018 11:34:59 +0000 (UTC) for IP:'10.11.54.3' DOMAIN:'int-mx03.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'esyr@redhat.com' RCPT:'' Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Mon, May 21, 2018 at 11:58:13AM -0700, Alexei Starovoitov wrote: > On Mon, May 21, 2018 at 02:29:30PM +0200, Eugene Syromiatnikov wrote: > > Hello. > > > > This patch set adds ability to set default values for > > kernel.unprivileged_bpf_disable, net.core.bpf_jit_harden, > > net.core.bpf_jit_kallsyms sysctl knobs as well as option to override > > them via a boot-time kernel parameter. > > Commits log not only should explain 'what' is being done by the patch, > but 'why' as well. Some BPF sysctl knobs affect the loading of BPF programs, and during system boot/init stages these sysctls are not yet configured. A concrete example is systemd, that has implemented loading of BPF programs. Thus, to allow controlling these setting at early boot, this patch set adds the ability to change the default setting of these sysctl knobs as well as option to override them via a boot-time kernel parameter (in order to avoid rebuilding kernel each time a need of changing these defaults arises). The sysctl knobs in question are kernel.unprivileged_bpf_disable, net.core.bpf_jit_harden, and net.core.bpf_jit_kallsyms. -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html