From: Masahiro Yamada <masahiroy@kernel.org> mainline inclusion from mainline-v5.14-rc1 commit 0d989ac2c90b5f51fe12102d3cddf54b959f2014 category: bugfix bugzilla: https://atomgit.com/openeuler/kernel/issues/1006 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- 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 <openssl/bio.h> | ^~~~~~~~~~~~~~~ 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 <gelf.h> 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 hurt 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_9ePsY... Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Conflicts: Makefile scripts/Makefile.build scripts/Makefile.modfinal [A major feature, "Add support for Clang LTO" https://lore.kernel.org/all/20201013003203.4168817-1-samitolvanen@google.com... has not been backported. Among the related commits, b1a1a1a09b46 ("kbuild: lto: postpone objtool") modified the context, resulting in conflicts.] Signed-off-by: Tengda Wu <wutengda2@huawei.com> --- Makefile | 74 +++++++++++++----------------------------- scripts/Makefile.build | 2 -- 2 files changed, 22 insertions(+), 54 deletions(-) diff --git a/Makefile b/Makefile index 8202c90707d9..ff2f9e0dbfb7 100644 --- a/Makefile +++ b/Makefile @@ -1112,41 +1112,6 @@ mod_sign_cmd = true endif export mod_sign_cmd -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 MODORDER := $(extmod-prefix)modules.order @@ -1255,7 +1220,7 @@ prepare0: archprepare $(Q)$(MAKE) $(build)=. # All the preparing.. -prepare: prepare0 prepare-objtool prepare-resolve_btfids +prepare: prepare0 # Support for using generic headers in asm-generic asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj @@ -1268,22 +1233,6 @@ 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_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 # --------------------------------------------------------------------------- @@ -1374,6 +1323,27 @@ 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 ($(quiet),silent_) tools_silent=s diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 585d4e98211c..5c1b1b9917a4 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -210,7 +210,6 @@ endif # CC_USING_RECORD_MCOUNT endif # CONFIG_FTRACE_MCOUNT_RECORD ifdef CONFIG_STACK_VALIDATION -ifneq ($(SKIP_STACK_VALIDATION),1) __objtool_obj := $(objtree)/tools/objtool/objtool @@ -247,7 +246,6 @@ objtool_obj = $(if $(patsubst y%,, \ $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \ $(__objtool_obj)) -endif # SKIP_STACK_VALIDATION endif # CONFIG_STACK_VALIDATION # Rebuild all objects when objtool changes, or is enabled/disabled. -- 2.34.1