From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: 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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 1A6BAC4338F for ; Mon, 23 Aug 2021 20:15:25 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3ACEA613D0 for ; Mon, 23 Aug 2021 20:15:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 3ACEA613D0 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4Gtk4m4V5nz2yg3 for ; Tue, 24 Aug 2021 06:15:20 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=permerror (SPF Permanent Error: Unknown mechanism found: ip:192.40.192.88/32) smtp.mailfrom=kernel.crashing.org (client-ip=63.228.1.57; helo=gate.crashing.org; envelope-from=segher@kernel.crashing.org; receiver=) Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) by lists.ozlabs.org (Postfix) with ESMTP id 4Gtk4K4jsCz2xr1 for ; Tue, 24 Aug 2021 06:14:56 +1000 (AEST) Received: from gate.crashing.org (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id 17NKCUqC005302; Mon, 23 Aug 2021 15:12:30 -0500 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id 17NKCOGl005277; Mon, 23 Aug 2021 15:12:24 -0500 X-Authentication-Warning: gate.crashing.org: segher set sender to segher@kernel.crashing.org using -f Date: Mon, 23 Aug 2021 15:12:19 -0500 From: Segher Boessenkool To: Christophe Leroy Subject: Re: [PATCH] powerpc/booke: Avoid link stack corruption in several places Message-ID: <20210823201219.GZ1583@gate.crashing.org> References: <20210823155837.GX1583@gate.crashing.org> <67a5be3f-a443-03eb-aa8e-a1fa6c0b3d3f@csgroup.eu> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <67a5be3f-a443-03eb-aa8e-a1fa6c0b3d3f@csgroup.eu> User-Agent: Mutt/1.4.2.3i X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Paul Mackerras , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Mon, Aug 23, 2021 at 07:05:38PM +0200, Christophe Leroy wrote: > Le 23/08/2021 à 17:58, Segher Boessenkool a écrit : > >On Mon, Aug 23, 2021 at 07:53:01AM +0000, Christophe Leroy wrote: > >> /* Be careful, this will clobber the lr register. */ > >> #define LOAD_REG_ADDR_PIC(reg, name) \ > >>- bl 0f; \ > >>+ bcl 20,31,0f \ > >> 0: mflr reg; \ > >> addis reg,reg,(name - 0b)@ha; \ > >> addi reg,reg,(name - 0b)@l; > > > >The code ended each line with a semicolon before, for absolutely no > >reason that I can see, but still. Fixing that would be nice, but only > >doing it on one line isn't good. > > Sure, forgetting the semicolon broke the build. That's because the > backslash removes the newline. Ah right, one of the surprises you get from using the C preprocessor on non-C code :-) > The cleanest way I found to fix that quite of stuff is by using GAS macro, > as I did for LOAD_REG_IMMEDIATE() some time ago. Yeah, good plan. You can use loops and saner parameters etc. as well if you do :-) > >Btw. Both the 7450 and the modern cores implementing this really need > >this to be $+4, so it is a lot clearer to write that instead of 1f or > >a named label. > > I like that, removing unneeded labels will make it smoother and clearer. > I'll do it. Cool, thanks! Segher