From: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Subject: kasan: fix clang compilation warning due to stack protector KASAN uses a single cc-option invocation to disable both conserve-stack and stack-protector flags. The former flag is not present in Clang, which causes cc-option to fail, and results in stack-protector being enabled. Fix by using separate cc-option calls for each flag. Also collect all flags in a variable to avoid calling cc-option multiple times for different files. Link: http://lkml.kernel.org/r/c2f0c8e4048852ae014f4a391d96ca42d27e3255.1590779332.git.andreyknvl@xxxxxxxxxx Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Reported-by: Qian Cai <cai@xxxxxx> Reviewed-by: Marco Elver <elver@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/kasan/Makefile | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) --- a/mm/kasan/Makefile~kasan-fix-clang-compilation-warning-due-to-stack-protector +++ a/mm/kasan/Makefile @@ -15,14 +15,19 @@ CFLAGS_REMOVE_tags_report.o = $(CC_FLAGS # Function splitter causes unnecessary splits in __asan_load1/__asan_store1 # see: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63533 -CFLAGS_common.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING -CFLAGS_generic.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING -CFLAGS_generic_report.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING -CFLAGS_init.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING -CFLAGS_quarantine.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING -CFLAGS_report.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING -CFLAGS_tags.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING -CFLAGS_tags_report.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING +CC_FLAGS_KASAN_RUNTIME := $(call cc-option, -fno-conserve-stack) +CC_FLAGS_KASAN_RUNTIME += $(call cc-option, -fno-stack-protector) +# Disable branch tracing to avoid recursion. +CC_FLAGS_KASAN_RUNTIME += -DDISABLE_BRANCH_PROFILING + +CFLAGS_common.o := $(CC_FLAGS_KASAN_RUNTIME) +CFLAGS_generic.o := $(CC_FLAGS_KASAN_RUNTIME) +CFLAGS_generic_report.o := $(CC_FLAGS_KASAN_RUNTIME) +CFLAGS_init.o := $(CC_FLAGS_KASAN_RUNTIME) +CFLAGS_quarantine.o := $(CC_FLAGS_KASAN_RUNTIME) +CFLAGS_report.o := $(CC_FLAGS_KASAN_RUNTIME) +CFLAGS_tags.o := $(CC_FLAGS_KASAN_RUNTIME) +CFLAGS_tags_report.o := $(CC_FLAGS_KASAN_RUNTIME) obj-$(CONFIG_KASAN) := common.o init.o report.o obj-$(CONFIG_KASAN_GENERIC) += generic.o generic_report.o quarantine.o _
