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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 09E9BC433EF for ; Mon, 16 May 2022 09:35:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230156AbiEPJf3 (ORCPT ); Mon, 16 May 2022 05:35:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58280 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229590AbiEPJf0 (ORCPT ); Mon, 16 May 2022 05:35:26 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B6D5F2DD49; Mon, 16 May 2022 02:35:25 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 5BDA5612BB; Mon, 16 May 2022 09:35:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5E9EAC34116; Mon, 16 May 2022 09:35:23 +0000 (UTC) Date: Mon, 16 May 2022 10:35:19 +0100 From: Catalin Marinas To: Andre Przywara Cc: Will Deacon , Shuah Khan , linux-arm-kernel@lists.infradead.org, Mark Brown , linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] kselftest/arm64: bti: force static linking Message-ID: References: <20220511172129.2078337-1-andre.przywara@arm.com> <20220516102935.67505a91@donnerap.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220516102935.67505a91@donnerap.cambridge.arm.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 16, 2022 at 10:29:35AM +0100, Andre Przywara wrote: > On Sun, 15 May 2022 11:05:23 +0100 > Catalin Marinas wrote: > > On Wed, May 11, 2022 at 06:21:29PM +0100, Andre Przywara wrote: > > > The "bti" selftests are built with -nostdlib, which apparently > > > automatically creates a statically linked binary, which is what we want > > > and need for BTI (to avoid interactions with the dynamic linker). > > > > > > However this is not true when building a PIE binary, which some > > > toolchains (Ubuntu) configure as the default. > > > When compiling btitest with such a toolchain, it will create a > > > dynamically linked binary, which will probably fail some tests, as the > > > dynamic linker might not support BTI: > > > =================== > > > TAP version 13 > > > 1..18 > > > not ok 1 nohint_func/call_using_br_x0 > > > not ok 2 nohint_func/call_using_br_x16 > > > not ok 3 nohint_func/call_using_blr > > > .... > > > =================== > > > > > > To make sure we create static binaries, add an explicit -static on the > > > linker command line. This forces static linking even if the toolchain > > > defaults to PIE builds, and fixes btitest runs on BTI enabled machines. > > > > > > Signed-off-by: Andre Przywara > > > > Does this need to go in as a fix (cc stable, fixes tag)? > > I dimly remember some discussion about stable fixes not being a real thing > for the selftests? In any case: > > Fixes: 314bcbf09f14 ("kselftest: arm64: Add BTI tests") I'll add the fixes tag. I can see the occasional cc stable for kselftest patches. -- Catalin