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=-14.6 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_IN_DEF_DKIM_WL 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 3EE14C169C4 for ; Mon, 11 Feb 2019 18:17:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F373121B24 for ; Mon, 11 Feb 2019 18:17:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="UjCK47gl" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731583AbfBKSRe (ORCPT ); Mon, 11 Feb 2019 13:17:34 -0500 Received: from mail-pf1-f193.google.com ([209.85.210.193]:40959 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727007AbfBKSRd (ORCPT ); Mon, 11 Feb 2019 13:17:33 -0500 Received: by mail-pf1-f193.google.com with SMTP id h1so2823407pfo.7 for ; Mon, 11 Feb 2019 10:17:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=eNKvlhATBFZVonShAC/U+yr/Q9vhBiyJjXe6MSCRJrE=; b=UjCK47glau/YbFQXXw4TC1dxBLiIYi/B8lKA/qe/XbMMNyCu55AqD0Za/FCdGQQxhw RrGN89Qs/xSPC5Je8OugJagNdxlYNelm5/8lijcXNLcYN0I5iIRmWj1QDW1XPgJWbtwf CA210PPgdgEfDAlPyYp97ESsSrmiVl4bQqgx5fvP5K6VutSPWOJWybyHChTX7Cc+RdSM SadzDW4vwziXkATSTo02DTAaMQWQ8L9EzEJ60wKg4cqbpGLQeGJsIoJkEwXTTkrwNPCo 0zV8olNa3n2YAcxqtRFntuyMqi6YLTOmdgexOfkoVZlWr9p6VQ0Z3EA+d9NHEiqnUhyF qcvA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=eNKvlhATBFZVonShAC/U+yr/Q9vhBiyJjXe6MSCRJrE=; b=lbea68tfDvzI+2sfsLRIm0JOy4emcPWm3X61lg072cDsEpgLGF5qFUzEV5mT/XxuGl KebRmZaIfp1+y8tBlTaLSOT14pQOVRgX6SjD/bG2kntFypKNUzhGzweZYczlVXwfEa7K lNV/+dI8AlriFv9C0GiH1FvV+VAI6w1w2M4vqwGqZ2sSs/wg4Y2ot82+9ICBgdR2J0di msLllJQncuast9VPeI+j75YW4J0LJly/2/C64V6hV0xn8aDmAnZ1NXwh92bS04bWeUhW vTtxazHbYJQrwG4Ol6mwMJ4Jde4ex1u8iSrx/2dfTYJ7m1gpvbxdwqAUdUe2gfzXMgrc xUNA== X-Gm-Message-State: AHQUAuYiW/sSIfKiWtoZVJzkiL4juQO/5mF84hHoSywcFOafgyFWjRmb 920SaP8JvbXuEXEttvG0Fl8mHIcpUc0RmqPGaHK4Tg== X-Google-Smtp-Source: AHgI3IbnG2wI8bPyuZz0pgcU88iFpQo08cAWVJj5p7WViaASCDiqapkdplLyT2zxrJ6Ox8S0TJVk/sK8iYRhES4fFkE= X-Received: by 2002:a62:109b:: with SMTP id 27mr37424825pfq.227.1549909052874; Mon, 11 Feb 2019 10:17:32 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Nick Desaulniers Date: Mon, 11 Feb 2019 10:17:21 -0800 Message-ID: Subject: Re: [PATCH 4/5] ARM: use unified assembler in c files To: Stefan Agner Cc: Russell King , Nathan Chancellor , Arnd Bergmann , Ard Biesheuvel , Nicolas Pitre , Thierry Reding , Will Deacon , julien.thierry@arm.com, Mark Rutland , LKML , Linux ARM Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Feb 9, 2019 at 9:28 AM Stefan Agner wrote: > > Thanks for the reviews so far. > > During some more testing I stumbled upon another issue: > > On 07.02.2019 10:48, Stefan Agner wrote: > > Use unified assembler syntax (UAL) in inline assembler. Divided > > syntax is considered depricated. This will also allow to build > > the kernel using LLVM's integrated assembler. > > > > Signed-off-by: Stefan Agner > > --- > > arch/arm/mm/copypage-v4mc.c | 2 +- > > arch/arm/mm/copypage-v4wb.c | 2 +- > > arch/arm/mm/copypage-v4wt.c | 2 +- > > 3 files changed, 3 insertions(+), 3 deletions(-) > > > > diff --git a/arch/arm/mm/copypage-v4mc.c b/arch/arm/mm/copypage-v4mc.c > > index b03202cddddb..b19c7ad1a6de 100644 > > --- a/arch/arm/mm/copypage-v4mc.c > > +++ b/arch/arm/mm/copypage-v4mc.c > > @@ -56,7 +56,7 @@ static void mc_copy_user_page(void *from, void *to) > > ldmia %0!, {r2, r3, ip, lr} @ 4\n\ > > subs %2, %2, #1 @ 1\n\ > > stmia %1!, {r2, r3, ip, lr} @ 4\n\ > > - ldmneia %0!, {r2, r3, ip, lr} @ 4\n\ > > + ldmiane %0!, {r2, r3, ip, lr} @ 4\n\ > > bne 1b @ " > > : "+&r" (from), "+&r" (to), "=&r" (tmp) > > : "2" (PAGE_SIZE / 64) > > diff --git a/arch/arm/mm/copypage-v4wb.c b/arch/arm/mm/copypage-v4wb.c > > index cd3e165afeed..6e3c9b69dd25 100644 > > --- a/arch/arm/mm/copypage-v4wb.c > > +++ b/arch/arm/mm/copypage-v4wb.c > > @@ -38,7 +38,7 @@ static void v4wb_copy_user_page(void *kto, const void *kfrom) > > ldmia %1!, {r3, r4, ip, lr} @ 4\n\ > > subs %2, %2, #1 @ 1\n\ > > stmia %0!, {r3, r4, ip, lr} @ 4\n\ > > - ldmneia %1!, {r3, r4, ip, lr} @ 4\n\ > > + ldmiane %1!, {r3, r4, ip, lr} @ 4\n\ > > bne 1b @ 1\n\ > > mcr p15, 0, %1, c7, c10, 4 @ 1 drain WB" > > : "+&r" (kto), "+&r" (kfrom), "=&r" (tmp) > > diff --git a/arch/arm/mm/copypage-v4wt.c b/arch/arm/mm/copypage-v4wt.c > > index 8614572e1296..4a40fa1cbc2a 100644 > > --- a/arch/arm/mm/copypage-v4wt.c > > +++ b/arch/arm/mm/copypage-v4wt.c > > @@ -34,7 +34,7 @@ static void v4wt_copy_user_page(void *kto, const void *kfrom) > > ldmia %1!, {r3, r4, ip, lr} @ 4\n\ > > subs %2, %2, #1 @ 1\n\ > > stmia %0!, {r3, r4, ip, lr} @ 4\n\ > > - ldmneia %1!, {r3, r4, ip, lr} @ 4\n\ > > + ldmiane %1!, {r3, r4, ip, lr} @ 4\n\ > > bne 1b @ 1\n\ > > mcr p15, 0, %2, c7, c7, 0 @ flush ID cache" > > : "+&r" (kto), "+&r" (kfrom), "=&r" (tmp) > > When compiling with gcc, this leads to: > > /tmp/ccrvA1wy.s: Assembler messages: > /tmp/ccrvA1wy.s:180: Error: bad instruction `ldmiane r0!,{r3,r4,ip,lr}' > make[1]: *** [scripts/Makefile.build:277: arch/arm/mm/copypage-v4wb.o] > Error 1 > make: *** [Makefile:1042: arch/arm/mm] Error 2 > > Unfortunately, the gcc option -masm-syntax-unified which allows unified > syntax in inline assembly is broken (see also > https://lkml.org/lkml/2019/1/7/1320). > > So this requires to sprinkle those inline assembly with ".syntax > unified" strings, similar to how I've done it in uaccess.h. Not sure if this is purely a bug in GCC; Clang treats inline asm statements as unique, so asm directives do not carry over from one inline asm statement to another. This has caused issues in other arch's inline assembly, where we need to repeat asm directives repeatedly for each inline asm statement. https://bugs.llvm.org/show_bug.cgi?id=19749 -- Thanks, ~Nick Desaulniers