Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1757332AbeAHMp4 (ORCPT <rfc822;ralf@linux-mips.org> + 1 other);
        Mon, 8 Jan 2018 07:45:56 -0500
Received: from twosheds.infradead.org ([90.155.92.209]:60778 "EHLO
        twosheds.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1755032AbeAHMpz (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Mon, 8 Jan 2018 07:45:55 -0500
Message-ID: <23bd8a874faf8ec048299f919799f86f.squirrel@twosheds.infradead.org>
In-Reply-To: <20180108110309.GH3040@hirez.programming.kicks-ass.net>
References: <1515363085-4219-1-git-send-email-dwmw@amazon.co.uk>
    <1515363085-4219-2-git-send-email-dwmw@amazon.co.uk>
    <20180108104512.GG3040@hirez.programming.kicks-ass.net>
    <1515408782.7317.33.camel@infradead.org>
    <20180108110309.GH3040@hirez.programming.kicks-ass.net>
Date: Mon, 8 Jan 2018 12:45:44 -0000
Subject: Re: [PATCH v6 01/10] x86/retpoline: Add initial retpoline support
From: "David Woodhouse" <dwmw2@infradead.org>
To: "Peter Zijlstra" <peterz@infradead.org>
Cc: "David Woodhouse" <dwmw2@infradead.org>,
        "Andi Kleen" <ak@linux.intel.com>, "Paul Turner" <pjt@google.com>,
        "LKML" <linux-kernel@vger.kernel.org>,
        "Linus Torvalds" <torvalds@linux-foundation.org>,
        "Greg Kroah-Hartman" <gregkh@linux-foundation.org>,
        "Tim Chen" <tim.c.chen@linux.intel.com>,
        "Dave Hansen" <dave.hansen@intel.com>, tglx@linutronix.de,
        "Kees Cook" <keescook@google.com>,
        "Rik van Riel" <riel@redhat.com>,
        "Andy Lutomirski" <luto@amacapital.net>,
        "Jiri Kosina" <jikos@kernel.org>, gnomes@lxorguk.ukuu.org.uk
User-Agent: SquirrelMail/1.4.22-21.fc27
MIME-Version: 1.0
Content-Type: text/plain;charset=utf-8
Content-Transfer-Encoding: 8bit
X-Priority: 3 (Normal)
Importance: Normal
X-SRS-Rewrite: SMTP reverse-path rewritten from <dwmw2@infradead.org> by twosheds.infradead.org. See http://www.infradead.org/rpr.html
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
Return-Path: <linux-kernel-owner@vger.kernel.org>


> On Mon, Jan 08, 2018 at 10:53:02AM +0000, David Woodhouse wrote:
>> On Mon, 2018-01-08 at 11:45 +0100, Peter Zijlstra wrote:
>> >
>> >
>> > Should this not use local name labels instead?
>> >
>> > .macro RETPOLINE_JMP reg:req
>> >         call    .Ldo_rop_\@
>> > .Lspec_trap_\@:
>> >         pause
>> >         jmp .Lspec_trap_\@
>> > .Ldo_rop_\@:
>> >         mov     \reg, (%_ASM_SP)
>> >         ret
>> > .endm
>>
>> Not if you want to be able to use them twice in the same .S file.
>
> Should work fine, the \@ expands to a per-instance magic thing IIRC. All
> the PTI helpers do this too and that works just fine, see
> arch/x86/entry/calling.h
>

Ah, OK. Will do that when home in a few hours then.

-- 
dwmw2