From patchwork Wed May 12 06:52:01 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 12252911 X-Patchwork-Delegate: kuba@kernel.org 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=-17.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 43115C433ED for ; Wed, 12 May 2021 06:53:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1FC2461928 for ; Wed, 12 May 2021 06:53:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230135AbhELGyJ (ORCPT ); Wed, 12 May 2021 02:54:09 -0400 Received: from conuserg-10.nifty.com ([210.131.2.77]:19436 "EHLO conuserg-10.nifty.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229580AbhELGyH (ORCPT ); Wed, 12 May 2021 02:54:07 -0400 Received: from grover.RMN.KIBA.LAB.jp (133-32-232-101.west.xps.vectant.ne.jp [133.32.232.101]) (authenticated) by conuserg-10.nifty.com with ESMTP id 14C6q4oR028643; Wed, 12 May 2021 15:52:05 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-10.nifty.com 14C6q4oR028643 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1620802326; bh=tGCmhtBz8IEEwu83dXllP0bNtsLvnPdEOYpyEWEPOmI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=A8vIXl+60SVnvIQU+xvxvU1m7mWDeIM9aCnTy8VllplyFJqYAhx/RqL67GCuIm+EQ KzPAt/GY/ZiKCuAFnYqWcL9/7QPREzldZp+/oifcxsbAd2gsGN57AOl3qiEcRYtfZU nWR5Q2aXsb/QaFc2RCfJBMLT9wf2V/udmxUaY1XCqMXkrzIedCaPW8nDxTspvysf19 NpnklKEdmt2ySFJmUXFwECNO4NWs89af190dqS3Kt43cDmdnuAQsP2Q+3R9IBiiXCk SSdPYryUQ69+F17dzdZpbEsn1gzQ0GUUL/4UKBNxutY9Rz/5RYqAExX25M4WciBTXi 1J6Kx13WNN18Q== X-Nifty-SrcIP: [133.32.232.101] From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: Masahiro Yamada , Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , John Fastabend , KP Singh , Martin KaFai Lau , Michal Marek , Song Liu , Yonghong Song , bpf@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH 2/2] kbuild: remove libelf checks from top Makefile Date: Wed, 12 May 2021 15:52:01 +0900 Message-Id: <20210512065201.35268-2-masahiroy@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20210512065201.35268-1-masahiroy@kernel.org> References: <20210512065201.35268-1-masahiroy@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org I do not see a good reason why only the libelf development package must be so carefully checked. Kbuild generally does not check host tools or libraries. For example, x86_64 defconfig fails to build with no libssl development package installed. scripts/extract-cert.c:21:10: fatal error: openssl/bio.h: No such file or directory 21 | #include | ^~~~~~~~~~~~~~~ To solve the build error, you need to install libssl-dev or openssl-devel package, depending on your distribution. 'apt-file search', 'dnf provides', etc. is your frined to find a proper package to install. This commit removes all the libelf checks from the top Makefile. If libelf is missing, objtool will fail to build in a similar pattern: .../linux/tools/objtool/include/objtool/elf.h:10:10: fatal error: gelf.h: No such file or directory 10 | #include You need to install libelf-dev, libelf-devel, or elfutils-libelf-devel to proceed. Another remarkable change is, CONFIG_STACK_VALIDATION (without CONFIG_UNWINDER_ORC) previously continued to build with a warning, but now it will treat missing libelf as an error. This is just a one-time installation, so it should not matter to break a build and make a user install the package. BTW, the traditional way to handle such checks is autotool, but according to [1], I do not expect the kernel build would have similar scripting like './configure' does. [1]: https://lore.kernel.org/lkml/CA+55aFzr2HTZVOuzpHYDwmtRJLsVzE-yqg2DHpHi_9ePsYp5ug@mail.gmail.com/ Signed-off-by: Masahiro Yamada Acked-by: Andrii Nakryiko --- Makefile | 78 +++++++++++---------------------------- scripts/Makefile.build | 2 - scripts/Makefile.modfinal | 2 - 3 files changed, 22 insertions(+), 60 deletions(-) diff --git a/Makefile b/Makefile index d60dc028f09c..bfbb7c8cbb0f 100644 --- a/Makefile +++ b/Makefile @@ -1081,41 +1081,6 @@ export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE) MODLIB = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE) export MODLIB -HOST_LIBELF_LIBS = $(shell pkg-config libelf --libs 2>/dev/null || echo -lelf) - -has_libelf = $(call try-run,\ - echo "int main() {}" | $(HOSTCC) $(KBUILD_HOSTLDFLAGS) -xc -o /dev/null $(HOST_LIBELF_LIBS) -,1,0) - -ifdef CONFIG_STACK_VALIDATION - ifeq ($(has_libelf),1) - objtool_target := tools/objtool FORCE - else - SKIP_STACK_VALIDATION := 1 - export SKIP_STACK_VALIDATION - endif -endif - -PHONY += resolve_btfids_clean - -resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids - -# tools/bpf/resolve_btfids directory might not exist -# in output directory, skip its clean in that case -resolve_btfids_clean: -ifneq ($(wildcard $(resolve_btfids_O)),) - $(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean -endif - -ifdef CONFIG_BPF -ifdef CONFIG_DEBUG_INFO_BTF - ifeq ($(has_libelf),1) - resolve_btfids_target := tools/bpf/resolve_btfids FORCE - else - ERROR_RESOLVE_BTFIDS := 1 - endif -endif # CONFIG_DEBUG_INFO_BTF -endif # CONFIG_BPF - PHONY += prepare0 export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/) @@ -1227,7 +1192,7 @@ prepare0: archprepare $(Q)$(MAKE) $(build)=. # All the preparing.. -prepare: prepare0 prepare-objtool prepare-resolve_btfids +prepare: prepare0 PHONY += remove-stale-files remove-stale-files: @@ -1244,26 +1209,6 @@ uapi-asm-generic: $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \ generic=include/uapi/asm-generic -PHONY += prepare-objtool prepare-resolve_btfids -prepare-objtool: $(objtool_target) -ifeq ($(SKIP_STACK_VALIDATION),1) -ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL - @echo "error: Cannot generate __mcount_loc for CONFIG_DYNAMIC_FTRACE=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2 - @false -endif -ifdef CONFIG_UNWINDER_ORC - @echo "error: Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2 - @false -else - @echo "warning: Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2 -endif -endif - -prepare-resolve_btfids: $(resolve_btfids_target) -ifeq ($(ERROR_RESOLVE_BTFIDS),1) - @echo "error: Cannot resolve BTF IDs for CONFIG_DEBUG_INFO_BTF, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2 - @false -endif # Generate some files # --------------------------------------------------------------------------- @@ -1354,6 +1299,27 @@ scripts_unifdef: scripts_basic # --------------------------------------------------------------------------- # Tools +ifdef CONFIG_STACK_VALIDATION +prepare: tools/objtool +endif + +ifdef CONFIG_BPF +ifdef CONFIG_DEBUG_INFO_BTF +prepare: tools/bpf/resolve_btfids +endif +endif + +PHONY += resolve_btfids_clean + +resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids + +# tools/bpf/resolve_btfids directory might not exist +# in output directory, skip its clean in that case +resolve_btfids_clean: +ifneq ($(wildcard $(resolve_btfids_O)),) + $(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean +endif + # Clear a bunch of variables before executing the submake ifeq ($(quiet),silent_) tools_silent=s diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 949f723efe53..7adc3a2c3c31 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -219,7 +219,6 @@ endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT ifdef CONFIG_STACK_VALIDATION ifndef CONFIG_LTO_CLANG -ifneq ($(SKIP_STACK_VALIDATION),1) __objtool_obj := $(objtree)/tools/objtool/objtool @@ -233,7 +232,6 @@ objtool_obj = $(if $(patsubst y%,, \ $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \ $(__objtool_obj)) -endif # SKIP_STACK_VALIDATION endif # CONFIG_LTO_CLANG endif # CONFIG_STACK_VALIDATION diff --git a/scripts/Makefile.modfinal b/scripts/Makefile.modfinal index dd87cea9fba7..bdee3babc5cf 100644 --- a/scripts/Makefile.modfinal +++ b/scripts/Makefile.modfinal @@ -39,12 +39,10 @@ prelink-ext := .lto # so let's now process the prelinked binary before we link the module. ifdef CONFIG_STACK_VALIDATION -ifneq ($(SKIP_STACK_VALIDATION),1) cmd_ld_ko_o += \ $(objtree)/tools/objtool/objtool $(objtool_args) \ $(@:.ko=$(prelink-ext).o); -endif # SKIP_STACK_VALIDATION endif # CONFIG_STACK_VALIDATION endif # CONFIG_LTO_CLANG