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| author | Masahiro Yamada <yamada.masahiro@socionext.com> | 2018-05-28 18:22:04 +0900 |
|---|---|---|
| committer | Masahiro Yamada <yamada.masahiro@socionext.com> | 2018-06-11 09:14:08 +0900 |
| commit | 5aadfdeb8de001ca04d500586e3b033404c28617 (patch) | |
| tree | a430e73a414b972a4a4cb71ba98fad5af960254d /scripts | |
| parent | 6a61b70b43c9c4cbc7314bf6c8b5ba8b0d6e1e7b (diff) | |
| download | linux-5aadfdeb8de001ca04d500586e3b033404c28617.tar.gz linux-5aadfdeb8de001ca04d500586e3b033404c28617.tar.bz2 linux-5aadfdeb8de001ca04d500586e3b033404c28617.zip | |
kcov: test compiler capability in Kconfig and correct dependency
As Documentation/kbuild/kconfig-language.txt notes, 'select' should be
be used with care - it forces a lower limit of another symbol, ignoring
the dependency. Currently, KCOV can select GCC_PLUGINS even if arch
does not select HAVE_GCC_PLUGINS. This could cause the unmet direct
dependency.
Now that Kconfig can test compiler capability, let's handle this in a
more sophisticated way.
There are two ways to enable KCOV; use the compiler that natively
supports -fsanitize-coverage=trace-pc, or build the SANCOV plugin if
the compiler has ability to build GCC plugins. Hence, the correct
dependency for KCOV is:
depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
You do not need to build the SANCOV plugin if the compiler already
supports -fsanitize-coverage=trace-pc. Hence, the select should be:
select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
With this, GCC_PLUGIN_SANCOV is selected only when necessary, so
scripts/Makefile.gcc-plugins can be cleaner.
I also cleaned up Kconfig and scripts/Makefile.kcov as well.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'scripts')
| -rw-r--r-- | scripts/Makefile.gcc-plugins | 8 | ||||
| -rw-r--r-- | scripts/Makefile.kcov | 10 | ||||
| -rw-r--r-- | scripts/gcc-plugins/Makefile | 4 |
3 files changed, 8 insertions, 14 deletions
diff --git a/scripts/Makefile.gcc-plugins b/scripts/Makefile.gcc-plugins index 7f5c86246138..708c8f6a5717 100644 --- a/scripts/Makefile.gcc-plugins +++ b/scripts/Makefile.gcc-plugins @@ -14,16 +14,12 @@ ifdef CONFIG_GCC_PLUGINS endif ifdef CONFIG_GCC_PLUGIN_SANCOV - ifeq ($(strip $(CFLAGS_KCOV)),) # It is needed because of the gcc-plugin.sh and gcc version checks. gcc-plugin-$(CONFIG_GCC_PLUGIN_SANCOV) += sancov_plugin.so - ifneq ($(PLUGINCC),) - CFLAGS_KCOV := $(SANCOV_PLUGIN) - else + ifeq ($(PLUGINCC),) $(warning warning: cannot use CONFIG_KCOV: -fsanitize-coverage=trace-pc is not supported by compiler) endif - endif endif gcc-plugin-$(CONFIG_GCC_PLUGIN_STRUCTLEAK) += structleak_plugin.so @@ -38,7 +34,7 @@ ifdef CONFIG_GCC_PLUGINS GCC_PLUGINS_CFLAGS := $(strip $(addprefix -fplugin=$(objtree)/scripts/gcc-plugins/, $(gcc-plugin-y)) $(gcc-plugin-cflags-y)) export PLUGINCC GCC_PLUGINS_CFLAGS GCC_PLUGIN GCC_PLUGIN_SUBDIR - export SANCOV_PLUGIN DISABLE_LATENT_ENTROPY_PLUGIN + export DISABLE_LATENT_ENTROPY_PLUGIN ifneq ($(PLUGINCC),) # SANCOV_PLUGIN can be only in CFLAGS_KCOV because avoid duplication. diff --git a/scripts/Makefile.kcov b/scripts/Makefile.kcov index 5cc72037e423..3d61c4bfcbee 100644 --- a/scripts/Makefile.kcov +++ b/scripts/Makefile.kcov @@ -1,7 +1,9 @@ ifdef CONFIG_KCOV -CFLAGS_KCOV := $(call cc-option,-fsanitize-coverage=trace-pc,) -ifeq ($(CONFIG_KCOV_ENABLE_COMPARISONS),y) -CFLAGS_KCOV += $(call cc-option,-fsanitize-coverage=trace-cmp,) -endif + +kcov-flags-$(CONFIG_CC_HAS_SANCOV_TRACE_PC) += -fsanitize-coverage=trace-pc +kcov-flags-$(CONFIG_KCOV_ENABLE_COMPARISONS) += -fsanitize-coverage=trace-cmp +kcov-flags-$(CONFIG_GCC_PLUGIN_SANCOV) += -fplugin=$(objtree)/scripts/gcc-plugins/sancov_plugin.so + +export CFLAGS_KCOV := $(kcov-flags-y) endif diff --git a/scripts/gcc-plugins/Makefile b/scripts/gcc-plugins/Makefile index e2ff425f4c7e..ea465799ced5 100644 --- a/scripts/gcc-plugins/Makefile +++ b/scripts/gcc-plugins/Makefile @@ -13,10 +13,6 @@ else export HOST_EXTRACXXFLAGS endif -ifneq ($(CFLAGS_KCOV), $(SANCOV_PLUGIN)) - GCC_PLUGIN := $(filter-out $(SANCOV_PLUGIN), $(GCC_PLUGIN)) -endif - export HOSTLIBS $(obj)/randomize_layout_plugin.o: $(objtree)/$(obj)/randomize_layout_seed.h |