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 D218BC433EF for ; Wed, 11 May 2022 20:52:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347890AbiEKUwW (ORCPT ); Wed, 11 May 2022 16:52:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34488 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240502AbiEKUwU (ORCPT ); Wed, 11 May 2022 16:52:20 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2C50E4D624; Wed, 11 May 2022 13:52:18 -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 ams.source.kernel.org (Postfix) with ESMTPS id DBB24B82617; Wed, 11 May 2022 20:52:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C670FC340EE; Wed, 11 May 2022 20:52:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1652302335; bh=hcTWqS1/6JNEKbDUnWjOFRHI/i50sXfXkf41lVpBiUQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=PQ6kXVe3mk9WbijP8yialUY26FPJdZZek0VQ97glkAophocZ78ag+Z+cbqXRkCud3 t/IJkpTKXPiSeyKFX6zDv2NQPeqP5hp5TlJt6NsPEFZgJ6clX5DndoZpGYXZJK7zWr NLwvowhEoNMsnvxZOX9T928N41cLWyh6R86/yPz960nVtV9B8YP3Vz8Is8KjgTwRZ4 wyF9uru+cjyo3ByvguTNiMIYU/v0RUoSulCuLeiqlDdi+tXuTejPwiaVmNw8kRvy2E dF1fiENoX8j5IwmuKnM441MnHbxU+3+IezmHa5GzPLjCkzEQDAWZ5WMfvX7AJ41VSw 9LZUpfiR6dSbA== Date: Wed, 11 May 2022 13:52:13 -0700 From: Nathan Chancellor To: Heiko Carstens Cc: Vasily Gorbik , Alexander Gordeev , Jonas Paulsson , Ulrich Weigand , Masahiro Yamada , Alexander Egorenkov , Sven Schnelle , Andreas Krebbel , Nathan Chancellor , Nick Desaulniers , linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org Subject: Re: [PATCH 0/8] s390: allow to build with llvm's integrated assembler Message-ID: References: <20220511120532.2228616-1-hca@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220511120532.2228616-1-hca@linux.ibm.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Heiko, On Wed, May 11, 2022 at 02:05:24PM +0200, Heiko Carstens wrote: > A couple of patches which in result make it finally possible to build the > kernel for s390 with llvm's integrated assembler. Several configs build > without errors or warnings, and the kernel also works as expected. > > Note that patch 6 ("s390/boot: workaround llvm IAS bug") reveals a > miscompile. This looks like a bug in the instruction definitions of the mvc > and clc instructions(?). I'd like to ask people to look into this, since > this silently generated broken code. I think it should be pretty simple to file a bug report for this since it occurs in a standalone assembly file? I agree with Nick that there should be a bug report filed and linked to in patch 6 so that we don't lose track of it. > This patch series is based on linux-next, which contains two additional > required s390 specific patches to make llvm's IAS work. > > Thanks, > Heiko > > Heiko Carstens (8): > s390/alternatives: provide identical sized orginal/alternative sequences > s390/alternatives: remove padding generation code > s390/entry: shorten OUTSIDE macro > s390/entry: workaround llvm's IAS limitations > s390/purgatory: workaround llvm's IAS limitations > s390/boot: workaround llvm IAS bug > s390/boot: do not emit debug info for assembly with llvm's IAS > scripts/min-tool-version.sh: raise minimum clang version to 14.0.0 for s390 > > arch/s390/Makefile | 2 + > arch/s390/boot/head.S | 34 +++++---- > arch/s390/include/asm/alternative-asm.h | 76 +++----------------- > arch/s390/include/asm/alternative.h | 93 ++++++------------------- > arch/s390/include/asm/spinlock.h | 2 +- > arch/s390/kernel/alternative.c | 61 +--------------- > arch/s390/kernel/entry.S | 39 +++++++---- > arch/s390/lib/spinlock.c | 4 +- > arch/s390/purgatory/head.S | 29 ++++++-- > scripts/min-tool-version.sh | 3 +- > 10 files changed, 104 insertions(+), 239 deletions(-) I applied this series to the latest s390 for-next branch (c4fb15578802) and built a few in-tree and distribution configurations with clang-14 and clang-15 then boot tested them in QEMU with a simple buildroot userspace. I did not see any new warnings or errors. This is awesome, I am excited to get this wired up in our CI! In case it is worthwhile: Tested-by: Nathan Chancellor Cheers, Nathan