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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 9C2BDC0044C for ; Wed, 31 Oct 2018 13:04:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5CFC920664 for ; Wed, 31 Oct 2018 13:04:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5CFC920664 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729304AbeJaWCo (ORCPT ); Wed, 31 Oct 2018 18:02:44 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58748 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729130AbeJaWCo (ORCPT ); Wed, 31 Oct 2018 18:02:44 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 03832C04C26D; Wed, 31 Oct 2018 13:04:47 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.43.17.31]) by smtp.corp.redhat.com (Postfix) with SMTP id 6A47D194B7; Wed, 31 Oct 2018 13:04:44 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Wed, 31 Oct 2018 14:04:45 +0100 (CET) Date: Wed, 31 Oct 2018 14:04:42 +0100 From: Oleg Nesterov To: Kees Cook Cc: Tycho Andersen , Andy Lutomirski , "Eric W . Biederman" , "Serge E . Hallyn" , Christian Brauner , Tyler Hicks , Akihiro Suda , Aleksa Sarai , LKML , Linux Containers , Linux API Subject: Re: [PATCH v8 1/2] seccomp: add a return code to trap to userspace Message-ID: <20181031130442.GB9007@redhat.com> References: <20181029224031.29809-1-tycho@tycho.ws> <20181029224031.29809-2-tycho@tycho.ws> <20181030150254.GB3385@redhat.com> <20181030155403.GC7343@cisco> <20181030162752.GB7643@redhat.com> <20181030163926.GC7643@redhat.com> <20181030172143.GD7343@cisco> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Wed, 31 Oct 2018 13:04:47 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/30, Kees Cook wrote: > > I'd like to avoid changing the return value of __secure_computing() to > just avoid having to touch all the callers. And I'd prefer not to > change __seccomp_filter() to a bool, since I'd like the return values > to be consistent through the call chain. Sure, please forget. > I find the existing code more readable than a single-line return, just > because it's very explicit. I don't want to have to think any harder > when reading seccomp. ;) Heh ;) Again, please forget, this is cosmetic. But I simply can't resist. I asked this question exactly because I was confused by these 2 lines: if (__seccomp_filter(this_syscall, NULL, true)) return -1; return 0; to me it looks as if we need to filter out some non-zero return values and turn them into -1. I had to spend some time (and think harder ;) to verify that this is just the recursive call and nothing more. nevermind, please ignore. Oleg.