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| author | Sami Tolvanen <samitolvanen@google.com> | 2020-04-13 16:10:13 -0700 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2021-02-23 12:46:57 -0800 |
| commit | b1a1a1a09b4606d41723a426110382d2077c26fb (patch) | |
| tree | 4c6672f8aa90443585f2ceb4cb4e65425d800c6a /scripts/Makefile.build | |
| parent | 41425ebe20245c99b44d6ba0f017be9bfc28414f (diff) | |
| download | linux-b1a1a1a09b4606d41723a426110382d2077c26fb.tar.bz2 | |
kbuild: lto: postpone objtool
With LTO, LLVM bitcode won't be compiled into native code until
modpost_link, or modfinal for modules. This change postpones calls
to objtool until after these steps, and moves objtool_args to
Makefile.lib, so the arguments can be reused in Makefile.modfinal.
As we didn't have objects to process earlier, we use --duplicate
when processing vmlinux.o. This change also disables unreachable
instruction warnings with LTO to avoid warnings about the int3
padding between functions.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'scripts/Makefile.build')
| -rw-r--r-- | scripts/Makefile.build | 22 |
1 files changed, 2 insertions, 20 deletions
diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 59fabd9685ee..3f6bf0ea7c0e 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -218,30 +218,11 @@ cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)), 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 -objtool_args = $(if $(CONFIG_UNWINDER_ORC),orc generate,check) - -objtool_args += $(if $(part-of-module), --module,) - -ifndef CONFIG_FRAME_POINTER -objtool_args += --no-fp -endif -ifdef CONFIG_GCOV_KERNEL -objtool_args += --no-unreachable -endif -ifdef CONFIG_RETPOLINE - objtool_args += --retpoline -endif -ifdef CONFIG_X86_SMAP - objtool_args += --uaccess -endif -ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL - objtool_args += --mcount -endif - # '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 @@ -253,6 +234,7 @@ objtool_obj = $(if $(patsubst y%,, \ $(__objtool_obj)) endif # SKIP_STACK_VALIDATION +endif # CONFIG_LTO_CLANG endif # CONFIG_STACK_VALIDATION # Rebuild all objects when objtool changes, or is enabled/disabled. |