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=-12.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 1124EC433E0 for ; Thu, 4 Feb 2021 18:13:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C32D064F45 for ; Thu, 4 Feb 2021 18:13:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238990AbhBDSNf (ORCPT ); Thu, 4 Feb 2021 13:13:35 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45700 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238952AbhBDSMV (ORCPT ); Thu, 4 Feb 2021 13:12:21 -0500 Received: from mail-io1-xd2c.google.com (mail-io1-xd2c.google.com [IPv6:2607:f8b0:4864:20::d2c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 51FA4C061788; Thu, 4 Feb 2021 10:11:41 -0800 (PST) Received: by mail-io1-xd2c.google.com with SMTP id n2so4202658iom.7; Thu, 04 Feb 2021 10:11:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:reply-to:from:date:message-id :subject:to:cc; bh=mX+HVztL7COZOVg08FHszVvmk8CCQMV0ipmWEw65Bsc=; b=II6mxEEra02hOipf+IprgYlfYGMxNWO3p1CvehqKhNyJJFq8mhYc0KZ4gbnmAGYd08 O8lfTLDZu4rRBrzpc7wM9ZRERAFYfcgwY4vtQqskffHAA6kgQYe4oBarP1GIZE6PUGpN KsAWjykgkrzSYQHRsKnVRuXwZUFvGpO+XB/ZxOpJovRiEPUNlLK/lQgqNqjtL3HAuSRP M/xwAIVlRs6+tCepphYjZvwUtXwe0Ebbc9h9Dp6QjmerUZleUymSmWZ4/LKwyeG3sbWY pavDpjgZucQ8NvYTH85/EXVmGoNko8pkmb6KNOeKgQHhfsHLFOqnnrTe9AFS1f4get/x vhtQ== 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:reply-to :from:date:message-id:subject:to:cc; bh=mX+HVztL7COZOVg08FHszVvmk8CCQMV0ipmWEw65Bsc=; b=IGU5aQjIHoqjZTcd+Eo2fpCqVn/zW32VVorqn12/r8emLUkl2sKU3vbfHPZx8zuw4+ 76Va51qWHEP8x+kKrE4g6mMAO10Gy9+2jHm+KGw8jeLdflB6isky/4/Bkqt4qIFmmyuT RIDcaNjrFrxgSrwqccjorKoqc14STWiX5kEBp8fMuCsb6wMvLcQfHrjuegocCKWaurX8 JvdtW0ZedJDb5fGBm3Nq5EZUNPqzlHt2jkmqxPB7p5KkNOccqu1EqRH4oo/yiMq5MswL MEQ976q1sg4qXv8eZ6rikxsiOTeX35uzCU6AZMx0KVWAzafNNdd0gab+4MIGM7PoKUbQ EUwA== X-Gm-Message-State: AOAM532hQjDswgzHJIDLd/InRoV7cKDUcMRMOZv++ik+CzTF4Waqxdeu IdZSMa4BkqKIbRPSPPlfrXRFsSv1AyYeELqBnN8= X-Google-Smtp-Source: ABdhPJzooRkc7eG40RJB52QRYKk/HMotDMOmGbS0wDPNAKH3EL1UbtP4q3R8P2YVNB7VduLIvGu7VG0HrhDPCa2nz+g= X-Received: by 2002:a02:1649:: with SMTP id a70mr724319jaa.97.1612462300646; Thu, 04 Feb 2021 10:11:40 -0800 (PST) MIME-Version: 1.0 References: <20210111180609.713998-1-natechancellor@gmail.com> In-Reply-To: <20210111180609.713998-1-natechancellor@gmail.com> Reply-To: sedat.dilek@gmail.com From: Sedat Dilek Date: Thu, 4 Feb 2021 19:11:28 +0100 Message-ID: Subject: Re: [PATCH] bpf: Hoise pahole version checks into Kconfig To: Nathan Chancellor Cc: Masahiro Yamada , Michal Marek , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , linux-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 11, 2021 at 7:06 PM Nathan Chancellor wrote: > > After commit da5fb18225b4 ("bpf: Support pre-2.25-binutils objcopy for > vmlinux BTF"), having CONFIG_DEBUG_INFO_BTF enabled but lacking a valid > copy of pahole results in a kernel that will fully compile but fail to > link. The user then has to either install pahole or disable > CONFIG_DEBUG_INFO_BTF and rebuild the kernel but only after their build > has failed, which could have been a significant amount of time depending > on the hardware. > > Avoid a poor user experience and require pahole to be installed with an > appropriate version to select and use CONFIG_DEBUG_INFO_BTF, which is > standard for options that require a specific tools version. > > Suggested-by: Sedat Dilek > Signed-off-by: Nathan Chancellor > --- > MAINTAINERS | 1 + > init/Kconfig | 4 ++++ > lib/Kconfig.debug | 6 ++---- > scripts/link-vmlinux.sh | 13 ------------- > scripts/pahole-version.sh | 16 ++++++++++++++++ > 5 files changed, 23 insertions(+), 17 deletions(-) > create mode 100755 scripts/pahole-version.sh > > diff --git a/MAINTAINERS b/MAINTAINERS > index b8db7637263a..6f6e24285a94 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -3282,6 +3282,7 @@ F: net/core/filter.c > F: net/sched/act_bpf.c > F: net/sched/cls_bpf.c > F: samples/bpf/ > +F: scripts/pahole-version.sh > F: tools/bpf/ > F: tools/lib/bpf/ > F: tools/testing/selftests/bpf/ > diff --git a/init/Kconfig b/init/Kconfig > index b77c60f8b963..872c61b5d204 100644 > --- a/init/Kconfig > +++ b/init/Kconfig > @@ -74,6 +74,10 @@ config TOOLS_SUPPORT_RELR > config CC_HAS_ASM_INLINE > def_bool $(success,echo 'void foo(void) { asm inline (""); }' | $(CC) -x c - -c -o /dev/null) > > +config PAHOLE_VERSION > + int > + default $(shell,$(srctree)/scripts/pahole-version.sh $(PAHOLE)) > + > config CONSTRUCTORS > bool > depends on !UML > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug > index 7937265ef879..70c446af9664 100644 > --- a/lib/Kconfig.debug > +++ b/lib/Kconfig.debug > @@ -267,6 +267,7 @@ config DEBUG_INFO_DWARF4 > > config DEBUG_INFO_BTF > bool "Generate BTF typeinfo" > + depends on PAHOLE_VERSION >= 116 > depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED > depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST > help > @@ -274,12 +275,9 @@ config DEBUG_INFO_BTF > Turning this on expects presence of pahole tool, which will convert > DWARF type info into equivalent deduplicated BTF type info. > > -config PAHOLE_HAS_SPLIT_BTF > - def_bool $(success, test `$(PAHOLE) --version | sed -E 's/v([0-9]+)\.([0-9]+)/\1\2/'` -ge "119") > - > config DEBUG_INFO_BTF_MODULES > def_bool y > - depends on DEBUG_INFO_BTF && MODULES && PAHOLE_HAS_SPLIT_BTF > + depends on DEBUG_INFO_BTF && MODULES && PAHOLE_VERSION >= 119 > help > Generate compact split BTF type information for kernel modules. > > diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh > index 6eded325c837..eef40fa9485d 100755 > --- a/scripts/link-vmlinux.sh > +++ b/scripts/link-vmlinux.sh > @@ -139,19 +139,6 @@ vmlinux_link() > # ${2} - file to dump raw BTF data into > gen_btf() > { > - local pahole_ver > - > - if ! [ -x "$(command -v ${PAHOLE})" ]; then > - echo >&2 "BTF: ${1}: pahole (${PAHOLE}) is not available" > - return 1 > - fi > - > - pahole_ver=$(${PAHOLE} --version | sed -E 's/v([0-9]+)\.([0-9]+)/\1\2/') > - if [ "${pahole_ver}" -lt "116" ]; then > - echo >&2 "BTF: ${1}: pahole version $(${PAHOLE} --version) is too old, need at least v1.16" > - return 1 > - fi > - > vmlinux_link ${1} > > info "BTF" ${2} > diff --git a/scripts/pahole-version.sh b/scripts/pahole-version.sh > new file mode 100755 > index 000000000000..6de6f734a345 > --- /dev/null > +++ b/scripts/pahole-version.sh > @@ -0,0 +1,16 @@ > +#!/bin/sh > +# SPDX-License-Identifier: GPL-2.0 > +# > +# Usage: $ ./scripts/pahole-version.sh pahole > +# > +# Print the pahole version as a three digit string > +# such as `119' for pahole v1.19 etc. > + > +pahole="$*" > + > +if ! [ -x "$(command -v $pahole)" ]; then > + echo 0 > + exit 1 > +fi > + > +$pahole --version | sed -E 's/v([0-9]+)\.([0-9]+)/\1\2/' > Cannot say if all supported pahole in the Linux kernel have that feature/option: $ /opt/pahole/bin/pahole --numeric_version 120 - Sedat - > base-commit: e22d7f05e445165e58feddb4e40cc9c0f94453bc > -- > 2.30.0 >