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=-5.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 39F92ECE587 for ; Tue, 1 Oct 2019 13:27:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0F57820842 for ; Tue, 1 Oct 2019 13:27:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388451AbfJAN1f (ORCPT ); Tue, 1 Oct 2019 09:27:35 -0400 Received: from foss.arm.com ([217.140.110.172]:49660 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388337AbfJAN1e (ORCPT ); Tue, 1 Oct 2019 09:27:34 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6D2B91000; Tue, 1 Oct 2019 06:27:34 -0700 (PDT) Received: from arrakis.emea.arm.com (arrakis.cambridge.arm.com [10.1.196.78]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6A3973F534; Tue, 1 Oct 2019 06:27:33 -0700 (PDT) Date: Tue, 1 Oct 2019 14:27:31 +0100 From: Catalin Marinas To: Will Deacon Cc: Vincenzo Frascino , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, ard.biesheuvel@linaro.org, ndesaulniers@google.com, tglx@linutronix.de Subject: Re: [PATCH v3 1/5] arm64: vdso32: Introduce COMPAT_CC_IS_GCC Message-ID: <20191001132731.GG41399@arrakis.emea.arm.com> References: <20190920142738.qlsjwguc6bpnez63@willie-the-truck> <20190926214342.34608-1-vincenzo.frascino@arm.com> <20190926214342.34608-2-vincenzo.frascino@arm.com> <20191001131420.y3fsydlo7pg6ykfs@willie-the-truck> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191001131420.y3fsydlo7pg6ykfs@willie-the-truck> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 01, 2019 at 02:14:23PM +0100, Will Deacon wrote: > On Thu, Sep 26, 2019 at 10:43:38PM +0100, Vincenzo Frascino wrote: > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > > index 37c610963eee..0e5beb928af5 100644 > > --- a/arch/arm64/Kconfig > > +++ b/arch/arm64/Kconfig > > @@ -110,7 +110,7 @@ config ARM64 > > select GENERIC_STRNLEN_USER > > select GENERIC_TIME_VSYSCALL > > select GENERIC_GETTIMEOFDAY > > - select GENERIC_COMPAT_VDSO if (!CPU_BIG_ENDIAN && COMPAT) > > + select GENERIC_COMPAT_VDSO if (!CPU_BIG_ENDIAN && COMPAT && COMPATCC_IS_ARM_GCC) > > select HANDLE_DOMAIN_IRQ > > select HARDIRQS_SW_RESEND > > select HAVE_PCI > > @@ -313,6 +313,9 @@ config KASAN_SHADOW_OFFSET > > default 0xeffffff900000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS > > default 0xffffffffffffffff > > > > +config COMPATCC_IS_ARM_GCC > > + def_bool $(success,$(COMPATCC) --version | head -n 1 | grep -q "arm-.*-gcc") > > I've seen toolchains where the first part of the tuple is "armv7-", so they > won't get detected here. However, do we really need to detect this? If > somebody passes a duff compiler, then the build will fail in the same way as > if they passed it to CROSS_COMPILE=. Not sure what happens if we pass an aarch64 compiler. Can we end up with a 64-bit compat vDSO? -- Catalin