From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1752700AbcGGThz (ORCPT <rfc822;w@1wt.eu>);
	Thu, 7 Jul 2016 15:37:55 -0400
Received: from www.linutronix.de ([62.245.132.108]:46217 "EHLO
	Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1750985AbcGGThq (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Thu, 7 Jul 2016 15:37:46 -0400
Date: Thu, 7 Jul 2016 21:34:53 +0200 (CEST)
From: Thomas Gleixner <tglx@linutronix.de>
To: Kees Cook <keescook@chromium.org>
cc: LKML <linux-kernel@vger.kernel.org>, Rik van Riel <riel@redhat.com>,
        Casey Schaufler <casey@schaufler-ca.com>,
        PaX Team <pageexec@freemail.hu>,
        Brad Spengler <spender@grsecurity.net>,
        Russell King <linux@armlinux.org.uk>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will.deacon@arm.com>,
        Ard Biesheuvel <ard.biesheuvel@linaro.org>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Michael Ellerman <mpe@ellerman.id.au>, Tony Luck <tony.luck@intel.com>,
        Fenghua Yu <fenghua.yu@intel.com>,
        "David S. Miller" <davem@davemloft.net>,
        "x86@kernel.org" <x86@kernel.org>, Christoph Lameter <cl@linux.com>,
        Pekka Enberg <penberg@kernel.org>,
        David Rientjes <rientjes@google.com>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Andy Lutomirski <luto@kernel.org>, Borislav Petkov <bp@suse.de>,
        Mathias Krause <minipli@googlemail.com>, Jan Kara <jack@suse.cz>,
        Vitaly Wool <vitalywool@gmail.com>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Laura Abbott <labbott@fedoraproject.org>,
        "linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
        linux-ia64@vger.kernel.org,
        "linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
        sparclinux <sparclinux@vger.kernel.org>,
        linux-arch <linux-arch@vger.kernel.org>, Linux-MM <linux-mm@kvack.org>,
        "kernel-hardening@lists.openwall.com" 
	<kernel-hardening@lists.openwall.com>
Subject: Re: [PATCH 1/9] mm: Hardened usercopy
In-Reply-To: <CAGXu5jJWVow4i_M7Qg4ZFgZh3k_fUxUs4pDJSf5Yc8Q-FK9HoQ@mail.gmail.com>
Message-ID: <alpine.DEB.2.11.1607072133550.4083@nanos>
References: <1467843928-29351-1-git-send-email-keescook@chromium.org> <1467843928-29351-2-git-send-email-keescook@chromium.org> <alpine.DEB.2.11.1607070938430.4083@nanos> <CAGXu5jJWVow4i_M7Qg4ZFgZh3k_fUxUs4pDJSf5Yc8Q-FK9HoQ@mail.gmail.com>
User-Agent: Alpine 2.11 (DEB 23 2013-08-11)
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
X-Linutronix-Spam-Score: -1.0
X-Linutronix-Spam-Level: -
X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required,  ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001,URIBL_BLOCKED=0.001
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Thu, 7 Jul 2016, Kees Cook wrote:
> On Thu, Jul 7, 2016 at 3:42 AM, Thomas Gleixner <tglx@linutronix.de> wrote:
> > I'd rather make that a weak function returning 1 which can be replaced by
> > x86 for CONFIG_FRAME_POINTER=y. That also allows other architectures to
> > implement their specific frame checks.
> 
> Yeah, though I prefer CONFIG-controlled stuff over weak functions, but
> I agree, something like arch_check_stack_frame(...) or similar. I'll
> build something for this on the next revision.

I'm fine with CONFIG_CONTROLLED as long as the ifdeffery is limited to header
files.

Thanks,

	tglx