From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 2919313C3C0 for ; Tue, 7 May 2024 07:45:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715067937; cv=none; b=f6X9Iv9zdxOlkg87SHI1feiR4SR1TXPFYIwdRh0x+5MDCDV1cFa8z8mgGhRn+4HMYkL+n/7lwnUq/9AzTHsdtQD+7LHg15L+b+9UsxV/jQkRPDGk3sZcLRLoyz3ipDComRZk0tiPEf6KmeMZwuHVvfQFtX+gWuImcmjPjic/TzI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715067937; c=relaxed/simple; bh=lVju8t74Z+z4Q0tbilEYLbe3G8jbkqVvp9HTVSKSQ40=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=jYtsYZxVGiqmOdYxf6YPrNtVokEZdz1brcWdhJm1yfuatwa55bmIGXcid746m3+JTv16x3GDMIHq41tRey78KFL0DCncEIKsz/iz1bqswPPYyVKRmiE74EtrAtD8F5qUcF1YeX01If6gecXjwNrBiR0c9MN/VhzXCHVye0/soz0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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 3BADB106F; Tue, 7 May 2024 00:46:00 -0700 (PDT) Received: from [10.57.67.145] (unknown [10.57.67.145]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 96B843F762; Tue, 7 May 2024 00:45:32 -0700 (PDT) Message-ID: <8fdefaa9-675e-4b37-9456-896b9989d18f@arm.com> Date: Tue, 7 May 2024 08:45:31 +0100 Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/2] selftests/openat2: fix clang build failures: -static-libasan, LOCAL_HDRS Content-Language: en-GB To: John Hubbard , Shuah Khan Cc: Andrew Morton , =?UTF-8?Q?Ilpo_J=C3=A4rvinen?= , Maciej Wieczor-Retman , Christian Brauner , Muhammad Usama Anjum , Alexey Gladkov , Valentin Obst , linux-kselftest@vger.kernel.org, LKML , llvm@lists.linux.dev References: <20240504044336.14411-1-jhubbard@nvidia.com> From: Ryan Roberts In-Reply-To: <20240504044336.14411-1-jhubbard@nvidia.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 04/05/2024 05:43, John Hubbard wrote: > When building with clang via: > > make LLVM=1 -C tools/testing/selftests > > two distinct failures occur: > > 1) gcc requires -static-libasan in order to ensure that Address > Sanitizer's library is the first one loaded. However, this leads to > build failures on clang, when building via: > > make LLVM=1 -C tools/testing/selftests > > However, clang already does the right thing by default: it statically > links the Address Sanitizer if -fsanitize is specified. Therefore, fix > this by simply omitting -static-libasan for clang builds. And leave > behind a comment, because the whole reason for static linking might not > be obvious. > > 2) clang won't accept invocations of this form, but gcc will: > > $(CC) file1.c header2.h > > Fix this by using selftests/lib.mk facilities for tracking local header > file dependencies: add them to LOCAL_HDRS, leaving only the .c files to > be passed to the compiler. > > Cc: Ryan Roberts > Signed-off-by: John Hubbard Hi John, I sent out a similar fix a couple of weeks ago, see [1]. I don't think it got picked up though. It takes a slightly different approach, explicitly adding -static-libsan (note no 'a') for clang, instead of relying on its default. And it just drops helpers.h from the makefile altogether, on the assumption that it was a mistake; its just a header and shouldn't be compiled directly. I'm not exactly sure what the benefit of adding it to LOCAL_HDRS is? [1] https://lore.kernel.org/linux-kselftest/20240417160740.2019530-1-ryan.roberts@arm.com/ Thanks, Ryan > --- > tools/testing/selftests/openat2/Makefile | 14 ++++++++++++-- > 1 file changed, 12 insertions(+), 2 deletions(-) > > diff --git a/tools/testing/selftests/openat2/Makefile b/tools/testing/selftests/openat2/Makefile > index 254d676a2689..185dc76ebb5f 100644 > --- a/tools/testing/selftests/openat2/Makefile > +++ b/tools/testing/selftests/openat2/Makefile > @@ -1,8 +1,18 @@ > # SPDX-License-Identifier: GPL-2.0-or-later > > -CFLAGS += -Wall -O2 -g -fsanitize=address -fsanitize=undefined -static-libasan > +CFLAGS += -Wall -O2 -g -fsanitize=address -fsanitize=undefined > TEST_GEN_PROGS := openat2_test resolve_test rename_attack_test > > +# gcc requires -static-libasan in order to ensure that Address Sanitizer's > +# library is the first one loaded. However, clang already statically links the > +# Address Sanitizer if -fsanitize is specified. Therefore, simply omit > +# -static-libasan for clang builds. > +ifeq ($(LLVM),) > + CFLAGS += -static-libasan > +endif > + > +LOCAL_HDRS += helpers.h > + > include ../lib.mk > > -$(TEST_GEN_PROGS): helpers.c helpers.h > +$(TEST_GEN_PROGS): helpers.c > > base-commit: ddb4c3f25b7b95df3d6932db0b379d768a6ebdf7 > prerequisite-patch-id: b901ece2a5b78503e2fb5480f20e304d36a0ea27