Commit-ID: d3a325df8e6636d912436ef4a2d16accf3b1fe7f Gitweb: http://git.kernel.org/tip/d3a325df8e6636d912436ef4a2d16accf3b1fe7f Author: Josh Poimboeuf <jpoim...@redhat.com> AuthorDate: Thu, 3 Mar 2016 11:39:30 -0600 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Fri, 4 Mar 2016 12:18:23 +0100
objtool: Detect and warn if libelf is missing anddon't break the build With CONFIG_STACK_VALIDATION enabled, if the host system doesn't have a development version of libelf installed, the build fails with errors like: elf.h:22:18: fatal error: gelf.h: No such file or directory compilation terminated. Instead of failing to build, instead just print a warning and disable stack validation. Signed-off-by: Josh Poimboeuf <jpoim...@redhat.com> Cc: Andrew Morton <a...@linux-foundation.org> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Stephen Rothwell <s...@canb.auug.org.au> Cc: Sudip Mukherjee <sudipm.mukher...@gmail.com> Cc: Thomas Gleixner <t...@linutronix.de> Cc: linux-n...@vger.kernel.org Cc: li...@roeck-us.net Cc: live-patch...@vger.kernel.org Link: http://lkml.kernel.org/r/8c27fe00face60f42e888ddb3142c97e45223165.1457026550.git.jpoim...@redhat.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- Makefile | 13 ++++++++++++- scripts/Makefile.build | 2 ++ 2 files changed, 14 insertions(+), 1 deletion(-) diff --git a/Makefile b/Makefile index 2c27a01..60b7295 100644 --- a/Makefile +++ b/Makefile @@ -995,8 +995,19 @@ prepare0: archprepare FORCE # All the preparing.. prepare: prepare0 prepare-objtool +ifdef CONFIG_STACK_VALIDATION + has_libelf := $(shell echo "int main() {}" | $(HOSTCC) -xc -o /dev/null -lelf - &> /dev/null && echo 1 || echo 0) + ifeq ($(has_libelf),1) + objtool_target := tools/objtool FORCE + else + $(warning "Cannot use CONFIG_STACK_VALIDATION, please install libelf-dev or elfutils-libelf-devel") + SKIP_STACK_VALIDATION := 1 + export SKIP_STACK_VALIDATION + endif +endif + PHONY += prepare-objtool -prepare-objtool: $(if $(CONFIG_STACK_VALIDATION), tools/objtool FORCE) +prepare-objtool: $(objtool_target) # Generate some files # --------------------------------------------------------------------------- diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 130a452..e1bc190 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -242,6 +242,7 @@ cmd_record_mcount = \ endif ifdef CONFIG_STACK_VALIDATION +ifneq ($(SKIP_STACK_VALIDATION),1) __objtool_obj := $(objtree)/tools/objtool/objtool @@ -260,6 +261,7 @@ 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 define rule_cc_o_c
