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=-5.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 2EBE9C63777 for ; Tue, 24 Nov 2020 18:10:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CB87220897 for ; Tue, 24 Nov 2020 18:10:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="GhWd6eIT" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404171AbgKXSJz (ORCPT ); Tue, 24 Nov 2020 13:09:55 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:40885 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390790AbgKXSJz (ORCPT ); Tue, 24 Nov 2020 13:09:55 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1606241394; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=uUA8/aOgpZ26JxcYo0ZLju1cjGrlPjY1iezm4VSo/Pg=; b=GhWd6eITMF9ahzzmgCcELFdEbuk2UpvxGwWAxy1VPj7GkiN9MlgHtBQaNlFs0qS5YzmAcm RPv5NthTPuN47/pfmYBFqTmuAPx2KqhNrmgCsGOlz6jtCs0OKI27x6PXsbcIT3q7xT2+MH DLzLWRhLTFogtbx7yt8EfcjI3FHtFUM= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-460-QEKI0QbqNuOLThpMqBG3UA-1; Tue, 24 Nov 2020 13:09:52 -0500 X-MC-Unique: QEKI0QbqNuOLThpMqBG3UA-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 5D3FB809DDF; Tue, 24 Nov 2020 18:09:51 +0000 (UTC) Received: from oldenburg2.str.redhat.com (ovpn-112-141.ams2.redhat.com [10.36.112.141]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 7D70F5C1A3; Tue, 24 Nov 2020 18:09:46 +0000 (UTC) From: Florian Weimer To: Mark Wielaard Cc: Christian Brauner , linux-api@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, dev@opencontainers.org, corbet@lwn.net, Carlos O'Donell Subject: Re: [PATCH] syscalls: Document OCI seccomp filter interactions & workaround References: <87lfer2c0b.fsf@oldenburg2.str.redhat.com> <20201124122639.x4zqtxwlpnvw7ycx@wittgenstein> <878saq3ofx.fsf@oldenburg2.str.redhat.com> Date: Tue, 24 Nov 2020 19:09:44 +0100 In-Reply-To: (Mark Wielaard's message of "Tue, 24 Nov 2020 15:08:05 +0100") Message-ID: <87im9uzkwn.fsf@oldenburg2.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org * Mark Wielaard: > For valgrind the issue is statx which we try to use before falling back > to stat64, fstatat or stat (depending on architecture, not all define > all of these). The problem with these fallbacks is that under some > containers (libseccomp versions) they might return EPERM instead of > ENOSYS. This causes really obscure errors that are really hard to > diagnose. The probing sequence I proposed should also work for statx. 8-p > Don't you have the same issue with glibc for those architectures that > don't have fstatat or 32bit arches that need 64-bit time_t? And if so, > how are you working around containers possibly returning EPERM instead > of ENOSYS? That's a good point. I don't think many people run 32-bit containers in the cloud. The Y2038 changes in glibc impact 64-bit ports a little, but mostly on the fringes (e.g., clock_nanosleep vs nanosleep). Thanks, Florian -- Red Hat GmbH, https://de.redhat.com/ , Registered seat: Grasbrunn, Commercial register: Amtsgericht Muenchen, HRB 153243, Managing Directors: Charles Cachera, Brian Klemm, Laurie Krebs, Michael O'Neill