From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <SRS0=ecL9=TG=vger.kernel.org=linux-kernel-owner@kernel.org>
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=-2.4 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,
	MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 62D73C46460
	for <linux-kernel@archiver.kernel.org>; Mon,  6 May 2019 14:50:54 +0000 (UTC)
Received: from vger.kernel.org (vger.kernel.org [209.132.180.67])
	by mail.kernel.org (Postfix) with ESMTP id 3349B2053B
	for <linux-kernel@archiver.kernel.org>; Mon,  6 May 2019 14:50:54 +0000 (UTC)
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1727681AbfEFOux (ORCPT
        <rfc822;linux-kernel@archiver.kernel.org>);
        Mon, 6 May 2019 10:50:53 -0400
Received: from gate.crashing.org ([63.228.1.57]:56032 "EHLO gate.crashing.org"
        rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
        id S1726346AbfEFOtO (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
        Mon, 6 May 2019 10:49:14 -0400
Received: from gate.crashing.org (localhost.localdomain [127.0.0.1])
        by gate.crashing.org (8.14.1/8.14.1) with ESMTP id x46EmgOD026749;
        Mon, 6 May 2019 09:48:42 -0500
Received: (from segher@localhost)
        by gate.crashing.org (8.14.1/8.14.1/Submit) id x46Emeop026748;
        Mon, 6 May 2019 09:48:40 -0500
X-Authentication-Warning: gate.crashing.org: segher set sender to segher@kernel.crashing.org using -f
Date:   Mon, 6 May 2019 09:48:40 -0500
From:   Segher Boessenkool <segher@kernel.crashing.org>
To:     Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc:     Ingo Molnar <mingo@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Arnd Bergmann <arnd@arndb.de>, x86@kernel.org,
        Will Deacon <will.deacon@arm.com>,
        linux-kernel@vger.kernel.org,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Jason Baron <jbaron@akamai.com>,
        Ingo Molnar <mingo@redhat.com>,
        Andy Lutomirski <luto@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        linuxppc-dev@lists.ozlabs.org,
        Nathan Chancellor <natechancellor@gmail.com>,
        linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 00/10] implement DYNAMIC_DEBUG_RELATIVE_POINTERS
Message-ID: <20190506144840.GZ8599@gate.crashing.org>
References: <20190409212517.7321-1-linux@rasmusvillemoes.dk> <1afb0702-3cc5-ba4f-2bdd-604d9da2b846@rasmusvillemoes.dk> <20190506070544.GA66463@gmail.com> <25dfde77-fdad-0b99-75ec-4ba480058970@rasmusvillemoes.dk>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <25dfde77-fdad-0b99-75ec-4ba480058970@rasmusvillemoes.dk>
User-Agent: Mutt/1.4.2.3i
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Mon, May 06, 2019 at 09:34:55AM +0200, Rasmus Villemoes wrote:
> I _am_ bending the C rules a bit with the "extern some_var; asm
> volatile(".section some_section\nsome_var: blabla");". I should probably
> ask on the gcc list whether this way of defining a local symbol in
> inline assembly and referring to it from C is supposed to work, or it
> just happens to work by chance.

It only works by chance.  There is no way GCC can know the asm needs
that variable.  If you make it (or its address) an input of the asm it
should work as far as I can see?  (Need exact code to analyse it exactly).


Segher