From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oo1-xc30.google.com (mail-oo1-xc30.google.com [IPv6:2607:f8b0:4864:20::c30]) by sourceware.org (Postfix) with ESMTPS id B75393858401; Wed, 3 Apr 2024 14:46:33 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org B75393858401 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org B75393858401 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=2607:f8b0:4864:20::c30 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1712155595; cv=none; b=qEOlRIYMLaDqLErjeX54p++/Wr+OkdbVrdNf8+q2fD24XLQc9YK4qNfoUosXBLNPVM63rCQJv5Lt4h8FFvCPjXt4etMsndohos2fDvjMD7x1aCccjLN59fTYku1iLf52GyMMXi8KL9rXA0JXLVjlyc3ZtxAVYqGLCn4nxKNIFOU= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1712155595; c=relaxed/simple; bh=23YSbW1EEFqo+rJIPMNke0IlwXoGIosOIaA0Ew0LSfo=; h=DKIM-Signature:MIME-Version:From:Date:Message-ID:Subject:To; b=vICF/n1z74VJ4HLsv78QSKu6VQXgm5Q7uqmDTIZo6WZGHFUD/h/fhaYOpj5kirc7BYhyzj02TRq/E0pm3J3kCWBbIYz9hHYLwkKF8IrQNp3bnpw1ZiI/MwDPYCh2sRO1kal1NuQnS8bNwlK68dhuFtVKutbF1vORxH7z7Rs1XrI= ARC-Authentication-Results: i=1; server2.sourceware.org Received: by mail-oo1-xc30.google.com with SMTP id 006d021491bc7-5a529a1f69aso4073327eaf.3; Wed, 03 Apr 2024 07:46:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1712155593; x=1712760393; darn=sourceware.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :reply-to:in-reply-to:references:mime-version:from:to:cc:subject :date:message-id:reply-to; bh=21eLxaNsqn56YcIxmLnnT3S0wRDUc0aS/RryFt156zk=; b=m+gPPSI1OSrhOv64gfD+RxKa1MkzKT76sxPf1I62KWxHItndSOdse1ZNG+9kIjjmZv ExahdJmFozCh3+P3A21yevNvS08J72dM0QASH9D4Yg0RmkkWVlLVPb0NgJe9WDN+zrNJ ca6LBp6vg+CTCA7oMGKABlEAcuDlgy30V23FCNJSvvDaGrZmPd/JtG4COHhDkVp95u2q MArtFbi0aifZOax0MThQqHTh2eRAi/qHmrN9ayjd9pPVcvxdE9eikuHMpnaIx73FLGJF f4Z+nxQE02hbI8qmQaP00Z+xxvqBhQ1R0ywCpOLKt0s/ddTPl4FBQZayddChZX+ryMMF 9I5A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1712155593; x=1712760393; h=content-transfer-encoding:cc:to:subject:message-id:date:from :reply-to:in-reply-to:references:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=21eLxaNsqn56YcIxmLnnT3S0wRDUc0aS/RryFt156zk=; b=nX7ziWe2wx1W5Oz/KePqd/E8ouaTJhYyKm1PA8p+rVOUa+8MPG9+DR1299NDfAK5b+ HoxyT5zAgnu6fKd8s5oyKwtrGIxWkLVHYZZ3BRGu2fV85JNzkDTQUph0x0JxKNLiO+Kn 2ZvQdvu5Gz9Q/3/cUoHWE8N7y0bMxxiP4OrTm8pW+tnTZsoXIt8c3S7PnvZpzugCGXQ2 Y+s5RJjsqAvKlKad2v4HQdgOoNCHAPauijCvKu+828QfE6AKDuYadY9fCXCAmbKnST7+ pggPWzIvhwlyHAJrwKLSIgl0F+HI2/1QUfox++xcuzwXr2oydO++XwaI3AAbOp3TkeXm QAbg== X-Forwarded-Encrypted: i=1; AJvYcCWP4MX8GNLhMViO73SvkS3H3hAOUCF/gM2K8ySFJaayhphF8RkHWRW6qT3F4udoDfatRphwEr+Bw8AtHCO9gRmBSKVj0fjMNsuspgd5M5lTuGX4rYAtCPsy0ODpGViDumABmNCy9571AdiWF3ZP9+gE8swN74N0ZG90mInQmw+bxO1xpIoTcgd/PC+mdjJnfms= X-Gm-Message-State: AOJu0YznxNdX2eKw+lXXv0SaHM8M/T6/NPkbu1e9jtmGsLYc+47LShLH 5GCxEGnaJYqs1W+JhtdVr43Mb/EDL1loo8vVwI+BcNlQH+HToW+kL6OUddWlZ9GjIAy7SAMtiaF ZZDwwC4h4Rm+Ym/dSzLhwQtbg8hU= X-Google-Smtp-Source: AGHT+IHyAUQO6yYbgPMAXBZqKE+H9Vs8oxd/jXA6IeyVV6HnaafPEvIKUCbKxlMceWO1JHB8InZdqrZ/qXHA4asxiHk= X-Received: by 2002:a05:6820:270a:b0:5a5:2105:f209 with SMTP id db10-20020a056820270a00b005a52105f209mr16507263oob.6.1712155593056; Wed, 03 Apr 2024 07:46:33 -0700 (PDT) MIME-Version: 1.0 References: <20240329203909.GS9427@gnu.wildebeest.org> <20240401150617.GF19478@gnu.wildebeest.org> <12215cd2-16db-4ee4-bd98-6a4bcf318592@cs.ucla.edu> <6239192ba9ff8aad0752309a54b633dc75a57c77.camel@tugraz.at> <8e877d2f-01e0-c786-dea5-265edbdc0c07@suse.de> In-Reply-To: Reply-To: noloader@gmail.com From: Jeffrey Walton Date: Wed, 3 Apr 2024 10:46:21 -0400 Message-ID: Subject: Re: Sourceware mitigating and preventing the next xz-backdoor To: Martin Uecker Cc: Michael Matz , Ian Lance Taylor , Paul Koning , Paul Eggert , Sandra Loosemore , Mark Wielaard , overseers@sourceware.org, gcc@gcc.gnu.org, binutils@sourceware.org, gdb@sourceware.org, libc-alpha@sourceware.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Spam-Status: No, score=-0.1 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On Wed, Apr 3, 2024 at 10:33=E2=80=AFAM Martin Uecker via Gdb wrote: > > Am Mittwoch, dem 03.04.2024 um 16:00 +0200 schrieb Michael Matz: > > [...] > > (And, FWIW, testing for features isn't "complex". And have you looked = at > > other build systems? I have, and none of them are less complex, just > > opaque in different ways from make+autotools). > > I ask a very specific question: To what extend is testing > for features instead of semantic versions and/or supported > standards still necessary? This seems like a problematic approach > that may have been necessary decades ago, but it seems it may be > time to move on. I think it is still needed. As a first example, Musl does not define preprocessor macros to identify itself. The project feels features should be probed at build time with a tool like Autoconf. As a second example, activating code paths, like AVX2 and AVX512, requires ensuring the compiler actually supports the ISA. Building a program on an older distribution with an older compiler could run afoul. Jeff