Received: by 2002:a25:4158:0:0:0:0:0 with SMTP id o85csp2549165yba; Mon, 6 May 2019 07:51:57 -0700 (PDT) X-Google-Smtp-Source: APXvYqzx/1vUXwacRlk1lSBIPvgaKKgtJqb/t61gPsa8pVIzr7esyDnaaL8mVvfsOu9U889NiJ36 X-Received: by 2002:a63:fb58:: with SMTP id w24mr32684888pgj.444.1557154317566; Mon, 06 May 2019 07:51:57 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1557154317; cv=none; d=google.com; s=arc-20160816; b=UDewe8BKYwyzynvh9x5N/lIMDhQWVSmK8nrJwJFXE7mn0JVWZf2OwIUKiI3b8kpuzR cDywPVSZSao2cMp89QHdE57fdNUvF18gUpCmuK8unXv5PSDw/Hi+bcwsTEOcg9tnydge LUIMD59mID0UvEcjoUnk/D1wTxPvnC4jlECGzlJCToq323yGByqUzgyOA1IXv9ZZwZiA tV2jZ5FYuKDG51umpKTv7BbRZEsZFzH82WEgwXBhDddWWYn2BPNwr0iM/xdwzXY/g5ZG /jBfBprRMVqLWJ96Oapc2bPyrD9vvacAKfOV5J1uvmhm051fZKsHSrUAVRdHEqtiGjcM NZzA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date; bh=QPLe9WNtziZMrDDcPYrgSwgfRT0ZxQbyQWh7uNQAmCg=; b=oB6CtwSiVLL7jZ9jhtijEEHlDGTzw8kAW1x8z9F4BOWsoRL0eCRpTdOS5aMNwX4GXz Q0O6tyYzM3yL6sUIv6dQEPpNpSWXlA55MQgXPh//KNAMI6/cOqOROqX7yh35rebtGKPo Pu78KOb2OhwpCLod022kOq/92YveUedtkrJT+w9UF/Ci+5ZQWT64ptw8f8qh8I/iKlkJ r/5k18Vg4tmzx8dfoCBV3vXd80rBdKYzKesbHQ92GYfrLEei7o1N0Grm/xbfEGWFBTM5 9BzpIwuFwdpIFVYJELVrIYKVgirnIdcoiZG/FbTZF0TGUKDJpfg4lt4fFFiSumniVmoE Za5w== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id h18si14508996pgg.265.2019.05.06.07.51.41; Mon, 06 May 2019 07:51:57 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728616AbfEFOuv (ORCPT + 99 others); Mon, 6 May 2019 10:50:51 -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 ); 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 To: Rasmus Villemoes Cc: Ingo Molnar , Nick Desaulniers , Arnd Bergmann , x86@kernel.org, Will Deacon , linux-kernel@vger.kernel.org, Linus Torvalds , Jason Baron , Ingo Molnar , Andy Lutomirski , Andrew Morton , linuxppc-dev@lists.ozlabs.org, Nathan Chancellor , 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: 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