From 5aadfdeb8de001ca04d500586e3b033404c28617 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Mon, 28 May 2018 18:22:04 +0900 Subject: 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 Reviewed-by: Kees Cook --- scripts/gcc-plugins/Makefile | 4 ---- 1 file changed, 4 deletions(-) (limited to 'scripts/gcc-plugins') 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 -- cgit v1.2.3 From 59f53855babf757ac7be19995670ab884aaf9b71 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Mon, 28 May 2018 18:22:06 +0900 Subject: gcc-plugins: test plugin support in Kconfig and clean up Makefile Run scripts/gcc-plugin.sh from Kconfig so that users can enable GCC_PLUGINS only when the compiler supports building plugins. Kconfig defines a new symbol, PLUGIN_HOSTCC. This will contain the compiler (g++ or gcc) used for building plugins, or empty if the plugin can not be supported at all. This allows us to remove all ugly testing in Makefile.gcc-plugins. Signed-off-by: Masahiro Yamada Acked-by: Kees Cook --- arch/Kconfig | 10 ++++++ scripts/Kconfig.include | 3 ++ scripts/Makefile.gcc-plugins | 79 ++++++++++++-------------------------------- scripts/gcc-plugins/Makefile | 1 + 4 files changed, 36 insertions(+), 57 deletions(-) (limited to 'scripts/gcc-plugins') diff --git a/arch/Kconfig b/arch/Kconfig index 2c7c3cf8adfc..e4a47d640a87 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -398,6 +398,15 @@ config SECCOMP_FILTER See Documentation/prctl/seccomp_filter.txt for details. +preferred-plugin-hostcc := $(if-success,[ $(gcc-version) -ge 40800 ],$(HOSTCXX),$(HOSTCC)) + +config PLUGIN_HOSTCC + string + default "$(shell,$(srctree)/scripts/gcc-plugin.sh "$(preferred-plugin-hostcc)" "$(HOSTCXX)" "$(CC)")" + help + Host compiler used to build GCC plugins. This can be $(HOSTCXX), + $(HOSTCC), or a null string if GCC plugin is unsupported. + config HAVE_GCC_PLUGINS bool help @@ -407,6 +416,7 @@ config HAVE_GCC_PLUGINS menuconfig GCC_PLUGINS bool "GCC plugins" depends on HAVE_GCC_PLUGINS + depends on PLUGIN_HOSTCC != "" depends on !COMPILE_TEST help GCC plugins are loadable modules that provide extra features to the diff --git a/scripts/Kconfig.include b/scripts/Kconfig.include index bf7c0c9fa3a4..dad5583451af 100644 --- a/scripts/Kconfig.include +++ b/scripts/Kconfig.include @@ -25,3 +25,6 @@ cc-option = $(success,$(CC) -Werror $(1) -E -x c /dev/null -o /dev/null) # $(ld-option,) # Return y if the linker supports , n otherwise ld-option = $(success,$(LD) -v $(1)) + +# gcc version including patch level +gcc-version := $(shell,$(srctree)/scripts/gcc-version.sh -p $(CC) | sed 's/^0*//') diff --git a/scripts/Makefile.gcc-plugins b/scripts/Makefile.gcc-plugins index 32bdf184eced..c961b9a65d11 100644 --- a/scripts/Makefile.gcc-plugins +++ b/scripts/Makefile.gcc-plugins @@ -1,72 +1,37 @@ # SPDX-License-Identifier: GPL-2.0 -ifdef CONFIG_GCC_PLUGINS - __PLUGINCC := $(call cc-ifversion, -ge, 0408, $(HOSTCXX), $(HOSTCC)) - PLUGINCC := $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-plugin.sh "$(__PLUGINCC)" "$(HOSTCXX)" "$(CC)") - - SANCOV_PLUGIN := -fplugin=$(objtree)/scripts/gcc-plugins/sancov_plugin.so - - gcc-plugin-$(CONFIG_GCC_PLUGIN_CYC_COMPLEXITY) += cyc_complexity_plugin.so +gcc-plugin-$(CONFIG_GCC_PLUGIN_CYC_COMPLEXITY) += cyc_complexity_plugin.so - gcc-plugin-$(CONFIG_GCC_PLUGIN_LATENT_ENTROPY) += latent_entropy_plugin.so - gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_LATENT_ENTROPY) += -DLATENT_ENTROPY_PLUGIN - ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY +gcc-plugin-$(CONFIG_GCC_PLUGIN_LATENT_ENTROPY) += latent_entropy_plugin.so +gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_LATENT_ENTROPY) += -DLATENT_ENTROPY_PLUGIN +ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY DISABLE_LATENT_ENTROPY_PLUGIN += -fplugin-arg-latent_entropy_plugin-disable - endif - - ifdef CONFIG_GCC_PLUGIN_SANCOV - # It is needed because of the gcc-plugin.sh and gcc version checks. - gcc-plugin-$(CONFIG_GCC_PLUGIN_SANCOV) += sancov_plugin.so - - ifeq ($(PLUGINCC),) - $(warning warning: cannot use CONFIG_KCOV: -fsanitize-coverage=trace-pc is not supported by compiler) - endif - endif - - gcc-plugin-$(CONFIG_GCC_PLUGIN_STRUCTLEAK) += structleak_plugin.so - gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STRUCTLEAK_VERBOSE) += -fplugin-arg-structleak_plugin-verbose - gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL) += -fplugin-arg-structleak_plugin-byref-all - gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STRUCTLEAK) += -DSTRUCTLEAK_PLUGIN +endif - gcc-plugin-$(CONFIG_GCC_PLUGIN_RANDSTRUCT) += randomize_layout_plugin.so - gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_RANDSTRUCT) += -DRANDSTRUCT_PLUGIN - gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_RANDSTRUCT_PERFORMANCE) += -fplugin-arg-randomize_layout_plugin-performance-mode +gcc-plugin-$(CONFIG_GCC_PLUGIN_SANCOV) += sancov_plugin.so +gcc-plugin-$(CONFIG_GCC_PLUGIN_STRUCTLEAK) += structleak_plugin.so +gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STRUCTLEAK_VERBOSE) += -fplugin-arg-structleak_plugin-verbose +gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL) += -fplugin-arg-structleak_plugin-byref-all +gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STRUCTLEAK) += -DSTRUCTLEAK_PLUGIN - GCC_PLUGINS_CFLAGS := $(strip $(addprefix -fplugin=$(objtree)/scripts/gcc-plugins/, $(gcc-plugin-y)) $(gcc-plugin-cflags-y)) +gcc-plugin-$(CONFIG_GCC_PLUGIN_RANDSTRUCT) += randomize_layout_plugin.so +gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_RANDSTRUCT) += -DRANDSTRUCT_PLUGIN +gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_RANDSTRUCT_PERFORMANCE) += -fplugin-arg-randomize_layout_plugin-performance-mode - export PLUGINCC GCC_PLUGINS_CFLAGS GCC_PLUGIN GCC_PLUGIN_SUBDIR - export DISABLE_LATENT_ENTROPY_PLUGIN +GCC_PLUGINS_CFLAGS := $(strip $(addprefix -fplugin=$(objtree)/scripts/gcc-plugins/, $(gcc-plugin-y)) $(gcc-plugin-cflags-y)) - ifneq ($(PLUGINCC),) - # SANCOV_PLUGIN can be only in CFLAGS_KCOV because avoid duplication. - GCC_PLUGINS_CFLAGS := $(filter-out $(SANCOV_PLUGIN), $(GCC_PLUGINS_CFLAGS)) - endif +export GCC_PLUGINS_CFLAGS GCC_PLUGIN GCC_PLUGIN_SUBDIR +export DISABLE_LATENT_ENTROPY_PLUGIN - KBUILD_CFLAGS += $(GCC_PLUGINS_CFLAGS) - GCC_PLUGIN := $(gcc-plugin-y) - GCC_PLUGIN_SUBDIR := $(gcc-plugin-subdir-y) -endif +# sancov_plugin.so can be only in CFLAGS_KCOV because avoid duplication. +GCC_PLUGINS_CFLAGS := $(filter-out %/sancov_plugin.so, $(GCC_PLUGINS_CFLAGS)) -# If plugins aren't supported, abort the build before hard-to-read compiler -# errors start getting spewed by the main build. -PHONY += gcc-plugins-check -gcc-plugins-check: FORCE -ifdef CONFIG_GCC_PLUGINS - ifeq ($(PLUGINCC),) - ifneq ($(GCC_PLUGINS_CFLAGS),) - ifeq ($(call cc-ifversion, -ge, 0405, y), y) - $(Q)$(srctree)/scripts/gcc-plugin.sh --show-error "$(__PLUGINCC)" "$(HOSTCXX)" "$(CC)" || true - @echo "Cannot use CONFIG_GCC_PLUGINS: your gcc installation does not support plugins, perhaps the necessary headers are missing?" >&2 && exit 1 - else - @echo "Cannot use CONFIG_GCC_PLUGINS: your gcc version does not support plugins, you should upgrade it to at least gcc 4.5" >&2 && exit 1 - endif - endif - endif -endif - @: +KBUILD_CFLAGS += $(GCC_PLUGINS_CFLAGS) +GCC_PLUGIN := $(gcc-plugin-y) +GCC_PLUGIN_SUBDIR := $(gcc-plugin-subdir-y) # Actually do the build, if requested. PHONY += gcc-plugins -gcc-plugins: scripts_basic gcc-plugins-check +gcc-plugins: scripts_basic ifdef CONFIG_GCC_PLUGINS $(Q)$(MAKE) $(build)=scripts/gcc-plugins endif diff --git a/scripts/gcc-plugins/Makefile b/scripts/gcc-plugins/Makefile index ea465799ced5..326254653bd0 100644 --- a/scripts/gcc-plugins/Makefile +++ b/scripts/gcc-plugins/Makefile @@ -1,4 +1,5 @@ # SPDX-License-Identifier: GPL-2.0 +PLUGINCC := $(CONFIG_PLUGIN_HOSTCC:"%"=%) GCC_PLUGINS_DIR := $(shell $(CC) -print-file-name=plugin) ifeq ($(PLUGINCC),$(HOSTCC)) -- cgit v1.2.3