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 S1757757AbcAOLLr (ORCPT <rfc822;w@1wt.eu>);
	Fri, 15 Jan 2016 06:11:47 -0500
Received: from mail.skyhub.de ([78.46.96.112]:41599 "EHLO mail.skyhub.de"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1754225AbcAOLLp (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
	Fri, 15 Jan 2016 06:11:45 -0500
Date: Fri, 15 Jan 2016 12:11:28 +0100
From: Borislav Petkov <bp@alien8.de>
To: Ingo Molnar <mingo@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>, Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
        x86@kernel.org, linux-kernel@vger.kernel.org,
        live-patching@vger.kernel.org, Michal Marek <mmarek@suse.cz>,
        Peter Zijlstra <peterz@infradead.org>,
        Andy Lutomirski <luto@kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Andi Kleen <andi@firstfloor.org>, Pedro Alves <palves@redhat.com>,
        Namhyung Kim <namhyung@gmail.com>,
        Bernd Petrovitsch <bernd@petrovitsch.priv.at>,
        Chris J Arges <chris.j.arges@canonical.com>,
        Andrew Morton <akpm@linux-foundation.org>, Jiri Slaby <jslaby@suse.cz>,
        Arnaldo Carvalho de Melo <acme@kernel.org>
Subject: Re: [PATCH v15 13/25] x86/reboot: Add ljmp instructions to stacktool
 whitelist
Message-ID: <20160115111128.GD25104@pd.tnic>
References: <cover.1450442274.git.jpoimboe@redhat.com>
 <c0c1a92df921961cae5cce208247bb8d8a975d6d.1450442274.git.jpoimboe@redhat.com>
 <20160112164711.GD22699@pd.tnic>
 <20160112174301.GD310@treble.redhat.com>
 <20160113105503.GB11575@gmail.com>
 <20160115060652.GA16760@treble.redhat.com>
 <20160115104145.GC25104@pd.tnic>
 <20160115110000.GB25002@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
In-Reply-To: <20160115110000.GB25002@gmail.com>
User-Agent: Mutt/1.5.24 (2015-08-30)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Fri, Jan 15, 2016 at 12:00:00PM +0100, Ingo Molnar wrote:
> All of the cases Josh listed involve some sort of special case where we do 
> something non-standard. (Where 'standard' == 'regular kernel C function'.)

My only worry is that next time we have to do something non-standard,
we'll have to annotate it as well. bpf_jit case-in-point.

OTOH, I guess the generic, tool-agnostic annotation could be a step
in the (more-)right direction as we're saying "we're doing something
special here, and we're stating that fact with this here annotation."

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.