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=-8.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 1CBB1C433DF for ; Tue, 16 Jun 2020 12:21:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E428520C09 for ; Tue, 16 Jun 2020 12:21:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="WCJ8C9Th" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728596AbgFPMVH (ORCPT ); Tue, 16 Jun 2020 08:21:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42518 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726052AbgFPMVH (ORCPT ); Tue, 16 Jun 2020 08:21:07 -0400 Received: from mail-il1-x143.google.com (mail-il1-x143.google.com [IPv6:2607:f8b0:4864:20::143]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EB78FC08C5C3 for ; Tue, 16 Jun 2020 05:21:06 -0700 (PDT) Received: by mail-il1-x143.google.com with SMTP id g3so3310322ilq.10 for ; Tue, 16 Jun 2020 05:21:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=2dyDpoLwIzV8Y2oUVWLUvllKR0lYbevMOUFT0R36afQ=; b=WCJ8C9ThcrJ9JyM+LwYLoP8teUs6OOqWzFt0B+WKUmQEDEJARfMFSYesiYcnxggBAO SL62uH4RsxB8ER24y/h+PA6x7JTVxMhOg82AcTYagDooAJo3f6UHmLWMlARu4z8y2MXE bg+RASloJPg/QWVzEyAuA+mQ4WSLUZ/NfgurTZYfatDjrt4aB7v1BSo8AvY0W5sy3/fb VtDpxR/N1pieOam7mj9O7r/vuPpWYEA7fthd7HnxpWgeUJU87sx3d2INqr+nBlfc+iTf bhZug5enKk5d8LgFHimwLSQamDALpuEszfYS7E2bz4CIH8K3GH/f1KbtgNHCeDJ8sxF9 0yUg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=2dyDpoLwIzV8Y2oUVWLUvllKR0lYbevMOUFT0R36afQ=; b=tfpApydsS776VHlP7nqwfMyU1M0hAFn0H6N5L6fdxnN/5HqscYrNZnHm7xImKrtxYy Jb+vRBub2+5gXQDPnIE1pv6wpTQyhe4CoDgPi/IHHF1sEi1QLprCdVAQmYWr5GX9jSYz aRSWX6DuJpaYZwrEtVKirtUrhtrt4GwCuxyhVOYRDb+SGqpKkOCHQgVfGROkVzzbn3ww CwRVMUGFTrT7TaKE02RN7xMPi8OE5f98uD9ClNnc66gFmLgDsyWcZ8b3MieqCi4HUKeT Rlc2yFtvGtySB5Cdpo76PTg+9vnoDn3JgHJ5XSGQ4Ll+I+TbFXQ0T46EwfPS+Nf9qsHi CndA== X-Gm-Message-State: AOAM531f1HAetAx1KeuM98ZJurdDYY+D4p5M2BAj48DfoIc//9fyCp3R Az2JXTjQHjjz8toSIGU6pk9HwdI7WtalpHfJA2PxPw== X-Google-Smtp-Source: ABdhPJxj/2UeGjR3VV5+VjjQqoipCAURYR0tK23aElL4GV7YqaJuZWLccb/peB86Plo7mlYW03p0aOiHACNJMDUEU0g= X-Received: by 2002:a92:a112:: with SMTP id v18mr2615151ili.278.1592310065900; Tue, 16 Jun 2020 05:21:05 -0700 (PDT) MIME-Version: 1.0 References: <20200616083435.223038-1-glider@google.com> <20200616100309.GA2614426@kroah.com> In-Reply-To: From: =?UTF-8?Q?Maciej_=C5=BBenczykowski?= Date: Tue, 16 Jun 2020 05:20:54 -0700 Message-ID: Subject: Re: [PATCH v2] [RFC] security: allow using Clang's zero initialization for stack variables To: Alexander Potapenko Cc: Greg KH , Masahiro Yamada , Kees Cook , James Morris , Nick Desaulniers , linux-security-module , LKML Content-Type: text/plain; charset="UTF-8" Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: > We could make INIT_STACK_ALL_ZERO fall back to INIT_STACK_ALL_PATTERN > if the compiler flag goes away - does this make sense? No, I'm pretty sure failing to build, or at least not setting anything is better. AFAIK pattern actually introduces new bugs that aren't visible at all with neither of these flags set. (because in practice the default no flag behaviour seems to zero some stuff [probably padding] that it doesn't with pattern)