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=-2.3 required=3.0 tests=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 60F55C352AA for ; Tue, 1 Oct 2019 14:58:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3116C21872 for ; Tue, 1 Oct 2019 14:58:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389577AbfJAO6D (ORCPT ); Tue, 1 Oct 2019 10:58:03 -0400 Received: from foss.arm.com ([217.140.110.172]:51790 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389029AbfJAO6C (ORCPT ); Tue, 1 Oct 2019 10:58:02 -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 1B41E1000; Tue, 1 Oct 2019 07:58:02 -0700 (PDT) Received: from [10.37.8.149] (unknown [10.37.8.149]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id BE5A73F71A; Tue, 1 Oct 2019 07:58:00 -0700 (PDT) Subject: Re: [PATCH v3 1/5] arm64: vdso32: Introduce COMPAT_CC_IS_GCC To: Will Deacon Cc: Catalin Marinas , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, ard.biesheuvel@linaro.org, ndesaulniers@google.com, tglx@linutronix.de 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> <20191001132731.GG41399@arrakis.emea.arm.com> <20191001142038.ptwyfbesfrz3kkoz@willie-the-truck> <7558914c-fc2d-d05a-ccbe-76ef451670ae@arm.com> <20191001144353.5rn3bkcc6eyfclh7@willie-the-truck> From: Vincenzo Frascino Message-ID: <7306ead0-a9b6-98d0-e775-c677eeeb55a5@arm.com> Date: Tue, 1 Oct 2019 15:59:51 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20191001144353.5rn3bkcc6eyfclh7@willie-the-truck> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/1/19 3:43 PM, Will Deacon wrote: > On Tue, Oct 01, 2019 at 03:37:49PM +0100, Vincenzo Frascino wrote: >> On 10/1/19 3:20 PM, Will Deacon wrote: >>> On Tue, Oct 01, 2019 at 03:20:35PM +0100, Vincenzo Frascino wrote: >>>> On 10/1/19 2:27 PM, Catalin Marinas wrote: >>>>> 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: >>>>>>> +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? >>>>> >>>> >>>> I agree with Catalin here. The problem is not only when you pass and aarch64 >>>> toolchain but even an x86 and so on. >>> >>> I disagree. What happens if you do: >>> >>> $ make ARCH=arm64 CROSS_COMPILE=x86_64-linux-gnu- >>> >>> on your x86 box? >>> >> >> The kernel compilation breaks as follows: >> >> x86_64-linux-gnu-gcc: error: unrecognized command line option ‘-mlittle-endian’; >> did you mean ‘-fconvert=little-endian’? >> /data1/Projects/LinuxKernel/linux/scripts/Makefile.build:265: recipe for target >> 'scripts/mod/empty.o' failed >> make[2]: *** [scripts/mod/empty.o] Error 1 >> /data1/Projects/LinuxKernel/linux/Makefile:1128: recipe for target 'prepare0' failed >> make[1]: *** [prepare0] Error 2 >> make[1]: Leaving directory '/data1/Projects/LinuxKernel/linux-out' >> Makefile:179: recipe for target 'sub-make' failed >> make: *** [sub-make] Error 2 >> >> Similar issue in the compat vdso library compilation if I do (without the check): >> >> $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- >> CROSS_COMPILE_COMPAT=x86_64-linux-gnu- >> >> With this check the compilation completes correctly but the compat vdso does not >> get built (unless my environment is playing me tricks ;) ). > > My point was that we don't attempt to sanitise the compiler passed via > CROSS_COMPILE, so I don't think we should do anything special for COMPATCC > either. > I agree on this, but the point I was trying to make is that the kernel should still be able to build even if the compiler for compat vdso is not correct. I do not have a strong opinion though. > Will > -- Regards, Vincenzo 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=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,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 40FBDC352AA for ; Tue, 1 Oct 2019 14:58:17 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 0B5FD215EA for ; Tue, 1 Oct 2019 14:58:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="sHgyo9ph" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0B5FD215EA Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-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=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date: Message-ID:From:References:To:Subject:Reply-To:Content-ID:Content-Description :Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=9wBLVYFsH0v3CtR3/nGLymkBYG7azE14DF4O5cThk9Q=; b=sHgyo9phnM4MVc U5eFyYnyIovUB/BBgPWdve6ecOaGIsl+BSHk3vNtYMEghUo31ESbm/vYApay2PkjTVpD8ewmp0icJ FbHcHMGQOTdFQdJ+XNyUKWviOGmKvJsW9W5le01kzCEfTiuTROVKepSGfySmxx0QkzDAPOQyJRxcM mSlGboi6k69wIlNzSbFNywoiLX/1FouP/3Il+6IUFmcLd0xBBshFFMkljVHeSuxIyubS66QbZyNV+ sRDUjQP0dVcrKZAiV5k4fIJIltY+8nrPSlPWQKoVsIyNu7HC16HBTIrElmjRV5KFYZ0atbMS2XD33 eIY8PG2X4MICQ3ZSFsjA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.2 #3 (Red Hat Linux)) id 1iFJbP-0003hJ-9A; Tue, 01 Oct 2019 14:58:11 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.2 #3 (Red Hat Linux)) id 1iFJbG-0003Xl-Q5 for linux-arm-kernel@lists.infradead.org; Tue, 01 Oct 2019 14:58:04 +0000 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 1B41E1000; Tue, 1 Oct 2019 07:58:02 -0700 (PDT) Received: from [10.37.8.149] (unknown [10.37.8.149]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id BE5A73F71A; Tue, 1 Oct 2019 07:58:00 -0700 (PDT) Subject: Re: [PATCH v3 1/5] arm64: vdso32: Introduce COMPAT_CC_IS_GCC To: Will Deacon 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> <20191001132731.GG41399@arrakis.emea.arm.com> <20191001142038.ptwyfbesfrz3kkoz@willie-the-truck> <7558914c-fc2d-d05a-ccbe-76ef451670ae@arm.com> <20191001144353.5rn3bkcc6eyfclh7@willie-the-truck> From: Vincenzo Frascino Message-ID: <7306ead0-a9b6-98d0-e775-c677eeeb55a5@arm.com> Date: Tue, 1 Oct 2019 15:59:51 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20191001144353.5rn3bkcc6eyfclh7@willie-the-truck> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191001_075802_941308_E4C16332 X-CRM114-Status: GOOD ( 17.76 ) 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: ard.biesheuvel@linaro.org, Catalin Marinas , ndesaulniers@google.com, linux-kernel@vger.kernel.org, tglx@linutronix.de, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org T24gMTAvMS8xOSAzOjQzIFBNLCBXaWxsIERlYWNvbiB3cm90ZToKPiBPbiBUdWUsIE9jdCAwMSwg MjAxOSBhdCAwMzozNzo0OVBNICswMTAwLCBWaW5jZW56byBGcmFzY2lubyB3cm90ZToKPj4gT24g MTAvMS8xOSAzOjIwIFBNLCBXaWxsIERlYWNvbiB3cm90ZToKPj4+IE9uIFR1ZSwgT2N0IDAxLCAy MDE5IGF0IDAzOjIwOjM1UE0gKzAxMDAsIFZpbmNlbnpvIEZyYXNjaW5vIHdyb3RlOgo+Pj4+IE9u IDEwLzEvMTkgMjoyNyBQTSwgQ2F0YWxpbiBNYXJpbmFzIHdyb3RlOgo+Pj4+PiBPbiBUdWUsIE9j dCAwMSwgMjAxOSBhdCAwMjoxNDoyM1BNICswMTAwLCBXaWxsIERlYWNvbiB3cm90ZToKPj4+Pj4+ IE9uIFRodSwgU2VwIDI2LCAyMDE5IGF0IDEwOjQzOjM4UE0gKzAxMDAsIFZpbmNlbnpvIEZyYXNj aW5vIHdyb3RlOgo+Pj4+Pj4+ICtjb25maWcgQ09NUEFUQ0NfSVNfQVJNX0dDQwo+Pj4+Pj4+ICsJ ZGVmX2Jvb2wgJChzdWNjZXNzLCQoQ09NUEFUQ0MpIC0tdmVyc2lvbiB8IGhlYWQgLW4gMSB8IGdy ZXAgLXEgImFybS0uKi1nY2MiKQo+Pj4+Pj4KPj4+Pj4+IEkndmUgc2VlbiB0b29sY2hhaW5zIHdo ZXJlIHRoZSBmaXJzdCBwYXJ0IG9mIHRoZSB0dXBsZSBpcyAiYXJtdjctIiwgc28gdGhleQo+Pj4+ Pj4gd29uJ3QgZ2V0IGRldGVjdGVkIGhlcmUuIEhvd2V2ZXIsIGRvIHdlIHJlYWxseSBuZWVkIHRv IGRldGVjdCB0aGlzPyBJZgo+Pj4+Pj4gc29tZWJvZHkgcGFzc2VzIGEgZHVmZiBjb21waWxlciwg dGhlbiB0aGUgYnVpbGQgd2lsbCBmYWlsIGluIHRoZSBzYW1lIHdheSBhcwo+Pj4+Pj4gaWYgdGhl eSBwYXNzZWQgaXQgdG8gQ1JPU1NfQ09NUElMRT0uCj4+Pj4+Cj4+Pj4+IE5vdCBzdXJlIHdoYXQg aGFwcGVucyBpZiB3ZSBwYXNzIGFuIGFhcmNoNjQgY29tcGlsZXIuIENhbiB3ZSBlbmQgdXAgd2l0 aAo+Pj4+PiBhIDY0LWJpdCBjb21wYXQgdkRTTz8KPj4+Pj4KPj4+Pgo+Pj4+IEkgYWdyZWUgd2l0 aCBDYXRhbGluIGhlcmUuIFRoZSBwcm9ibGVtIGlzIG5vdCBvbmx5IHdoZW4geW91IHBhc3MgYW5k IGFhcmNoNjQKPj4+PiB0b29sY2hhaW4gYnV0IGV2ZW4gYW4geDg2IGFuZCBzbyBvbi4KPj4+Cj4+ PiBJIGRpc2FncmVlLiBXaGF0IGhhcHBlbnMgaWYgeW91IGRvOgo+Pj4KPj4+ICQgbWFrZSBBUkNI PWFybTY0IENST1NTX0NPTVBJTEU9eDg2XzY0LWxpbnV4LWdudS0KPj4+Cj4+PiBvbiB5b3VyIHg4 NiBib3g/Cj4+Pgo+Pgo+PiBUaGUga2VybmVsIGNvbXBpbGF0aW9uIGJyZWFrcyBhcyBmb2xsb3dz Ogo+Pgo+PiB4ODZfNjQtbGludXgtZ251LWdjYzogZXJyb3I6IHVucmVjb2duaXplZCBjb21tYW5k IGxpbmUgb3B0aW9uIOKAmC1tbGl0dGxlLWVuZGlhbuKAmTsKPj4gZGlkIHlvdSBtZWFuIOKAmC1m Y29udmVydD1saXR0bGUtZW5kaWFu4oCZPwo+PiAvZGF0YTEvUHJvamVjdHMvTGludXhLZXJuZWwv bGludXgvc2NyaXB0cy9NYWtlZmlsZS5idWlsZDoyNjU6IHJlY2lwZSBmb3IgdGFyZ2V0Cj4+ICdz Y3JpcHRzL21vZC9lbXB0eS5vJyBmYWlsZWQKPj4gbWFrZVsyXTogKioqIFtzY3JpcHRzL21vZC9l bXB0eS5vXSBFcnJvciAxCj4+IC9kYXRhMS9Qcm9qZWN0cy9MaW51eEtlcm5lbC9saW51eC9NYWtl ZmlsZToxMTI4OiByZWNpcGUgZm9yIHRhcmdldCAncHJlcGFyZTAnIGZhaWxlZAo+PiBtYWtlWzFd OiAqKiogW3ByZXBhcmUwXSBFcnJvciAyCj4+IG1ha2VbMV06IExlYXZpbmcgZGlyZWN0b3J5ICcv ZGF0YTEvUHJvamVjdHMvTGludXhLZXJuZWwvbGludXgtb3V0Jwo+PiBNYWtlZmlsZToxNzk6IHJl Y2lwZSBmb3IgdGFyZ2V0ICdzdWItbWFrZScgZmFpbGVkCj4+IG1ha2U6ICoqKiBbc3ViLW1ha2Vd IEVycm9yIDIKPj4KPj4gU2ltaWxhciBpc3N1ZSBpbiB0aGUgY29tcGF0IHZkc28gbGlicmFyeSBj b21waWxhdGlvbiBpZiBJIGRvICh3aXRob3V0IHRoZSBjaGVjayk6Cj4+Cj4+ICQgbWFrZSBBUkNI PWFybTY0IENST1NTX0NPTVBJTEU9YWFyY2g2NC1saW51eC1nbnUtCj4+IENST1NTX0NPTVBJTEVf Q09NUEFUPXg4Nl82NC1saW51eC1nbnUtCj4+Cj4+IFdpdGggdGhpcyBjaGVjayB0aGUgY29tcGls YXRpb24gY29tcGxldGVzIGNvcnJlY3RseSBidXQgdGhlIGNvbXBhdCB2ZHNvIGRvZXMgbm90Cj4+ IGdldCBidWlsdCAodW5sZXNzIG15IGVudmlyb25tZW50IGlzIHBsYXlpbmcgbWUgdHJpY2tzIDsp ICkuCj4gCj4gTXkgcG9pbnQgd2FzIHRoYXQgd2UgZG9uJ3QgYXR0ZW1wdCB0byBzYW5pdGlzZSB0 aGUgY29tcGlsZXIgcGFzc2VkIHZpYQo+IENST1NTX0NPTVBJTEUsIHNvIEkgZG9uJ3QgdGhpbmsg d2Ugc2hvdWxkIGRvIGFueXRoaW5nIHNwZWNpYWwgZm9yIENPTVBBVENDCj4gZWl0aGVyLgo+CgpJ IGFncmVlIG9uIHRoaXMsIGJ1dCB0aGUgcG9pbnQgSSB3YXMgdHJ5aW5nIHRvIG1ha2UgaXMgdGhh dCB0aGUga2VybmVsIHNob3VsZApzdGlsbCBiZSBhYmxlIHRvIGJ1aWxkIGV2ZW4gaWYgdGhlIGNv bXBpbGVyIGZvciBjb21wYXQgdmRzbyBpcyBub3QgY29ycmVjdC4KCkkgZG8gbm90IGhhdmUgYSBz dHJvbmcgb3BpbmlvbiB0aG91Z2guCgo+IFdpbGwKPiAKCi0tIApSZWdhcmRzLApWaW5jZW56bwoK X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KbGludXgtYXJt LWtlcm5lbCBtYWlsaW5nIGxpc3QKbGludXgtYXJtLWtlcm5lbEBsaXN0cy5pbmZyYWRlYWQub3Jn Cmh0dHA6Ly9saXN0cy5pbmZyYWRlYWQub3JnL21haWxtYW4vbGlzdGluZm8vbGludXgtYXJtLWtl cm5lbAo=