From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f182.google.com (mail-pf1-f182.google.com [209.85.210.182]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9FF8914EC47 for ; Wed, 16 Oct 2024 22:18:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729117138; cv=none; b=ZeF3+x1p89b60x0NUUWC7r/cZh93Wt55mcJbQXOtGUlcWmHbxD0/wfCrBBDXtWPjgj0zAySmcWEbdF5apZG9ZrS0DHmZN61gesj/HwLYZIxV8mAOb8+q++Rc+txb0VlsjgC3fEK/fqO8h/EG2DnvAM+zOmpP0lOO26zUBxucmmw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729117138; c=relaxed/simple; bh=Fe6+xGzl6Uo0953U+p/DYb85hpULEorJSCHIoYA/3uk=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=JS2LzWdrQ+AfqIsV+mhCpDzbRwU3cj4+u8PxNg+Cd/m8Bw2MEOVhKdM8yzdaRXIfMXNjfrpYvbfJUN8ndirkHfcG1n+AXkilvKwlosAoyaizJjYVanJfryOTmhh9ZLQ72hU6hy5JMFqvaY+zpZWo6bA4Swpo+T6t2jHGlw0v/xA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=VdM97qLL; arc=none smtp.client-ip=209.85.210.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="VdM97qLL" Received: by mail-pf1-f182.google.com with SMTP id d2e1a72fcca58-71e49ef3b2bso202698b3a.2 for ; Wed, 16 Oct 2024 15:18:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1729117136; x=1729721936; darn=vger.kernel.org; h=mime-version:user-agent:content-transfer-encoding:references :in-reply-to:date:cc:to:from:subject:message-id:from:to:cc:subject :date:message-id:reply-to; bh=m9lG3UFqivqt8ceQwz6YRRlLk0aVwUnww1pm6vvyweU=; b=VdM97qLLXZV/vAgsi9HPNYNspY64sxRhFPTo+a7oNuV4dCKwzV9xiqM504NL+G9Fg/ qzL1qLB8WZplsP+wsGoa1Wlig1FC7QkrFGUUQuWC/GBduKaiylaBcZA5moXDQ7kbVley sjVcySdZb0kLFJA0+7qwWo0Dpm4+JZPxKR+qHv0XjYPkekLzEsmEVo7bPC/FWg45GOyf bmLG9Xgh3L+JoQZDvOfndrKgKQbNZHbuQs4F6pOt6FkFwOSaA3Evh4W8DZH7QYyZ5aWu FgR7vYpXtlpuUwGY5v+uzx5KBeSclEtB6nPTa72xA1TXUmAb+E3JDIGoY7oqdSfuQnNc AHHQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1729117136; x=1729721936; h=mime-version:user-agent:content-transfer-encoding:references :in-reply-to:date:cc:to:from:subject:message-id:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=m9lG3UFqivqt8ceQwz6YRRlLk0aVwUnww1pm6vvyweU=; b=iDUoHmzVL9O8bSKeaXj7FckmLSGafUFBwp2DtZV3LYloBm2S5ScD9stlwrqI/gpMOM OEs3ukKTB48301toxJpxLJ3O326Y3cMgiFGz5QfGGqoAgzsl4UgEoMw5DGh7aRWNxnEE mKLHIdzSJ7kQ3JcdiAJAjPIACDS8h/5A/fYgItB2yOrmlmCognIUVB4IGrcoVYjRCHUc Pw2TuGPZn3oAYujONgIeMgHhaQ6c7VCg1kEibSDUb4MxJ+kGZVCbDAY0BvxFcq6H5u+E KsgcC+PSBumpRwo+lchaODEc5kvLY3vuD5PsfPgaRX0jnyShHiRqm/RAReAtoak765UZ EB2w== X-Gm-Message-State: AOJu0YxsQOM6gM976I0HLi533aB+bmsmurpH/7WoRWp6nTyse3yR53hC 0pXcmIJ0ZAvdCBXF7ZGpxdeMO2VvjnDMUec22HXL11Y58b7O0VvQ X-Google-Smtp-Source: AGHT+IG019RXym2l4/8wZdtjCj5kXUjqudqVuyFfdhuX9ljpk1osreWpRmAxwumkv2G0d3pkSL/YhA== X-Received: by 2002:a05:6a20:2d22:b0:1d9:17fa:e5d8 with SMTP id adf61e73a8af0-1d917fb1118mr3455946637.26.1729117135960; Wed, 16 Oct 2024 15:18:55 -0700 (PDT) Received: from [192.168.0.235] ([38.34.87.7]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-7ea9c6c1948sm3792988a12.27.2024.10.16.15.18.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 16 Oct 2024 15:18:55 -0700 (PDT) Message-ID: <7fdc3253df59bd216eec02a53bbd0adc06fb8e7c.camel@gmail.com> Subject: Re: [PATCH bpf-next 3/3] selftests/bpf: Allow ignoring some flags for Clang builds From: Eduard Zingerman To: Andrii Nakryiko , Viktor Malik Cc: bpf@vger.kernel.org, Andrii Nakryiko , Mykola Lysenko , Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Shuah Khan , Nathan Chancellor , Nick Desaulniers , Bill Wendling , Justin Stitt Date: Wed, 16 Oct 2024 15:18:50 -0700 In-Reply-To: References: <08becac5b0b536d918adeb90efd63bdd7dcc856c.1728975031.git.vmalik@redhat.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.52.4 (3.52.4-1.fc40) Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Wed, 2024-10-16 at 13:37 -0700, Andrii Nakryiko wrote: > On Mon, Oct 14, 2024 at 11:55=E2=80=AFPM Viktor Malik = wrote: > >=20 > > There exist compiler flags supported by GCC but not supported by Clang > > (e.g. -specs=3D...). Currently, these cannot be passed to BPF selftests > > builds, even when building with GCC, as some binaries (urandom_read and > > liburandom_read.so) are always built with Clang and the unsupported > > flags make the compilation fail (as -Werror is turned on). > >=20 > > Add new Makefile variable CLANG_FILTEROUT_FLAGS which can be used by > > users to specify which flags (from the user-provided CFLAGS or LDFLAGS) > > should be filtered out for Clang invocations. > >=20 > > This allows to do things like: > >=20 > > $ CFLAGS=3D"-specs=3D/usr/lib/rpm/redhat/redhat-hardened-cc1" \ > > CLANG_FILTEROUT_FLAGS=3D"-specs=3D%" \ > > make -C tools/testing/selftests/bpf > >=20 > > Without this patch, the compilation would fail with: > >=20 > > [...] > > clang: error: argument unused during compilation: '-specs=3D/usr/li= b/rpm/redhat/redhat-hardened-cc1' [-Werror,-Wunused-command-line-argument] >=20 > maybe we should just not error out (i.e., enable > -Wno-unused-command-line-argument)? I agree with Andrii, grepping for FILTEROUT in kernel source code does not show anything similar to this. Are such filter-out variables some kind of convention? Another option might be to remove `-Werror` and add it on CI via EXTRA_CFLA= GS. [...]