Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752931AbaFBXFd (ORCPT ); Mon, 2 Jun 2014 19:05:33 -0400 Received: from mail-ob0-f172.google.com ([209.85.214.172]:42961 "EHLO mail-ob0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752797AbaFBXFa (ORCPT ); Mon, 2 Jun 2014 19:05:30 -0400 MIME-Version: 1.0 In-Reply-To: References: <1400799936-26499-1-git-send-email-keescook@chromium.org> Date: Mon, 2 Jun 2014 16:05:29 -0700 X-Google-Sender-Auth: E26drUiG60jXbPPELLldi_X79cQ Message-ID: Subject: Re: [PATCH v5 0/6] seccomp: add PR_SECCOMP_EXT and SECCOMP_EXT_ACT_TSYNC From: Kees Cook To: Andy Lutomirski , linux-api@vger.kernel.org, Andrew Morton Cc: Oleg Nesterov , James Morris , Stephen Rothwell , "David S. Miller" , LKML , Will Drewry , Julien Tinnes , Alexei Starovoitov Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 2, 2014 at 2:17 PM, Andy Lutomirski wrote: > On Mon, Jun 2, 2014 at 1:06 PM, Kees Cook wrote: >> On Mon, Jun 2, 2014 at 12:59 PM, Andy Lutomirski wrote: >>> On Mon, Jun 2, 2014 at 12:47 PM, Kees Cook wrote: >>>> Hi Andrew, >>>> >>>> Would you be willing to carry this series? Andy Lutomirski appears >>>> happy with it now. (Thanks again for all the feedback Andy!) If so, it >>>> has a relatively small merge conflict with the bpf changes living in >>>> net-next. Would you prefer I rebase against net-next, let sfr handle >>>> it, get carried in net-next, or some other option? >>> >>> Well, I'm still not entirely convinced that we want to have this much >>> multiplexing in a prctl, and I'm still a bit unconvinced that the code >> >> I don't want to get caught without interface argument flexibility >> again, so that's why the prctl interface is being set up that way. > > I was thinking that a syscall might be a lot prettier. It may pay to > cc linux-api, too. > > I'll offer you a deal: if you try to come up with a nice, clean > syscall, I'll try to write a fast(er) path for x86_64 to reduce > overhead. I bet I can save 90-100ns per syscall. :) Now added to the Cc. Which path do you mean to improve? Neither the prctl nor a syscall for this would need to be fast at all. I don't want to go in circles on this. I've been there before on my VFS link hardening series, and my module restriction series. I would like consensus from more than just one person. :) I'd like to hear from other folks on this (akpm?). My instinct is to continue using prctl since that is already where mediation for seccomp happens. I don't see why prctl vs a new syscall makes a difference here, frankly. -Kees -- Kees Cook Chrome OS Security -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/