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| author | Seth Forshee <seth.forshee@canonical.com> | 2019-07-17 11:06:26 -0500 |
|---|---|---|
| committer | Masahiro Yamada <yamada.masahiro@socionext.com> | 2019-07-20 11:20:24 +0900 |
| commit | 29be86d7f9cb18df4123f309ac7857570513e8bc (patch) | |
| tree | 60fdf871b68f29be66d9221d505e78f77f59ad93 /Makefile | |
| parent | 67bf47452ea00edd90e796054229b651e64b82c1 (diff) | |
| download | lwn-29be86d7f9cb18df4123f309ac7857570513e8bc.tar.gz lwn-29be86d7f9cb18df4123f309ac7857570513e8bc.zip | |
kbuild: add -fcf-protection=none when using retpoline flags
The gcc -fcf-protection=branch option is not compatible with
-mindirect-branch=thunk-extern. The latter is used when
CONFIG_RETPOLINE is selected, and this will fail to build with
a gcc which has -fcf-protection=branch enabled by default. Adding
-fcf-protection=none when building with retpoline enabled
prevents such build failures.
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Diffstat (limited to 'Makefile')
| -rw-r--r-- | Makefile | 6 |
1 files changed, 6 insertions, 0 deletions
@@ -882,6 +882,12 @@ KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init) # change __FILE__ to the relative path from the srctree KBUILD_CFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=) +# ensure -fcf-protection is disabled when using retpoline as it is +# incompatible with -mindirect-branch=thunk-extern +ifdef CONFIG_RETPOLINE +KBUILD_CFLAGS += $(call cc-option,-fcf-protection=none) +endif + # use the deterministic mode of AR if available KBUILD_ARFLAGS := $(call ar-option,D) |