Commit 90a35349 authored by Masahiro Yamada's avatar Masahiro Yamada
Browse files

kbuild: reuse $(cmd_objtool) for cmd_cc_lto_link_modules 



For CONFIG_LTO_CLANG=y, the objtool processing is not possible at the
compilation, hence postponed by the link time.

Reuse $(cmd_objtool) for CONFIG_LTO_CLANG=y by defining objtool-enabled
properly.

For CONFIG_LTO_CLANG=y:

  objtool-enabled is off for %.o compilation
  objtool-enabled is on  for %.lto link

For CONFIG_LTO_CLANG=n:

  objtool-enabled is on for %.o compilation
      (but, it depends on OBJECT_FILE_NON_STANDARD)

Set part-of-module := y for %.lto.o to avoid repeating --module.

Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
Reviewed-by: default avatarKees Cook <keescook@chromium.org>
Acked-by: default avatarJosh Poimboeuf <jpoimboe@redhat.com>
parent ef62588c

scripts/Makefile.build

+17 −11
Original line number Diff line number Diff line
@@ -236,20 +236,26 @@ objtool_args = \ 
	$(if $(CONFIG_X86_SMAP), --uaccess)				\

	$(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount)



ifndef CONFIG_LTO_CLANG

cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool_args) $@)

cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd)



endif # CONFIG_STACK_VALIDATION



ifdef CONFIG_LTO_CLANG



# Skip objtool for LLVM bitcode

$(obj)/%.o: objtool-enabled :=



else



# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory

# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file

# 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file



objtool-enabled = $(if $(filter-out y%, \

$(obj)/%.o: objtool-enabled = $(if $(filter-out y%, \

	$(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n),y)



cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool_args) $@)

cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd)



endif # CONFIG_LTO_CLANG

endif # CONFIG_STACK_VALIDATION

endif



ifdef CONFIG_TRIM_UNUSED_KSYMS

cmd_gen_ksymdeps = \
@@ -289,13 +295,13 @@ cmd_cc_lto_link_modules = \ 
	$(LD) $(ld_flags) -r -o $@					\

		$(shell [ -s $(@:.lto.o=.o.symversions) ] &&		\

			echo -T $(@:.lto.o=.o.symversions))		\

		--whole-archive $(filter-out FORCE,$^)

		--whole-archive $(filter-out FORCE,$^)			\

		$(cmd_objtool)



ifdef CONFIG_STACK_VALIDATION

# objtool was skipped for LLVM bitcode, run it now that we have compiled

# modules into native code

cmd_cc_lto_link_modules += ; $(objtool) $(objtool_args) --module $@

endif

$(obj)/%.lto.o: objtool-enabled = y

$(obj)/%.lto.o: part-of-module := y



$(obj)/%.lto.o: $(obj)/%.o FORCE

	$(call if_changed,cc_lto_link_modules)