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=-4.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 037ECC433FE for ; Mon, 7 Dec 2020 19:06:03 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 9440E238E3 for ; Mon, 7 Dec 2020 19:06:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9440E238E3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Subject:To:From: Message-ID:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=+j1BHVIToUkEyveOEWnn3M1xG3P0shMWVzBFraLbqAI=; b=EScuoMp/Q/9crD/zN6xmee91A ZBTNNX0S6PWUQ+41QSBHOFEv0+oy/6DTkv4jFaxpAvftKxAH6F19s/IfK5gwS4OH+R5Hx6ONhHrqR 9jjj1cBiZoxdoP66wpm//IVG0ORBm6A0SBVxSNw7H6ILp3S513rb39MILDr8GCuBMSOplWKJYBbVI pANVT5MRKi5aj4NyQySIgOJPHz5dzG230ACBu9Nycj+kjBG1EYVlQ7bQ+b3A05p43lKe8pjNV6dTI GO7TT0V2+XGXxEjoAPOHa3sM+iNcYWFHNYKbcRwXGV5IO7rtcU+8QrQloOYpfIG47asI3pcvhzQnt XJ7TeK9Mw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kmLoZ-0005Oh-LV; Mon, 07 Dec 2020 19:04:51 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kmLoX-0005Ny-Oe for linux-arm-kernel@lists.infradead.org; Mon, 07 Dec 2020 19:04:50 +0000 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B0E63238E2; Mon, 7 Dec 2020 19:04:48 +0000 (UTC) Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=wait-a-minute.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94) (envelope-from ) id 1kmLoT-00Gqbd-Vs; Mon, 07 Dec 2020 19:04:46 +0000 Date: Mon, 07 Dec 2020 19:04:44 +0000 Message-ID: <87360h5tf7.wl-maz@kernel.org> From: Marc Zyngier To: Robin Murphy Subject: Re: [PATCH] arm64: Work around broken GCC handling of "S" constraint In-Reply-To: References: <20201207154341.1004276-1-maz@kernel.org> <87316821c90a13a912a624250055f50f@kernel.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 Emacs/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: robin.murphy@arm.com, ardb@kernel.org, kernel-team@android.com, catalin.marinas@arm.com, dbrazdil@google.com, will@kernel.org, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201207_140449_873496_96B00487 X-CRM114-Status: GOOD ( 20.88 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Will Deacon , Catalin Marinas , kvmarm , David Brazdil , Android Kernel Team , Ard Biesheuvel , Linux ARM Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Robin, On Mon, 07 Dec 2020 18:42:23 +0000, Robin Murphy wrote: > > On 2020-12-07 17:47, Ard Biesheuvel wrote: > > On Mon, 7 Dec 2020 at 18:41, Marc Zyngier wrote: > >> > >> On 2020-12-07 17:19, Ard Biesheuvel wrote: > >>> (resend with David's email address fixed) > >> > >> Irk. Thanks for that. > >> > >>>>> +#ifdef CONFIG_CC_HAS_BROKEN_S_CONSTRAINT > >>>>> +#define SYM_CONSTRAINT "i" > >>>>> +#else > >>>>> +#define SYM_CONSTRAINT "S" > >>>>> +#endif > >>>>> + > >>>> > >>>> Could we just check GCC_VERSION here? > >> > >> I guess we could. But I haven't investigated which exact range of > >> compiler is broken (GCC 6.3 seems fixed, but that's the oldest > >> I have apart from the offending 4.9). > >> > > > > I tried 5.4 on godbolt, and it seems happy. And the failure will be > > obvious, so we can afford to get it slightly wrong and refine it > > later. > > FWIW the Linaro 14.11, 15.02 and 15.05 releases of GCC 4.9.3 seem to > build rc7 without complaint. The only thing older that I have to hand > is Ubuntu's GCC 4.8.4, which Kbuild chokes on entirely now. Can you try kvmarm/next? David's PSCI relay is breaking badly here. Thanks, M. -- Without deviation from the norm, progress is not possible. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel