On Thu, 28 May 2020 at 19:20, 'Andrey Konovalov' via kasan-dev <kasan-dev@xxxxxxxxxxxxxxxx> wrote: > > 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. > > Reported-by: Qian Cai <cai@xxxxxx> > Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> > --- Thank you! I was about to send an almost identical patch, as I encountered this when using clang. Reviewed-by: Marco Elver <elver@xxxxxxxxxx> > mm/kasan/Makefile | 21 +++++++++++++-------- > 1 file changed, 13 insertions(+), 8 deletions(-) > > diff --git a/mm/kasan/Makefile b/mm/kasan/Makefile > index de3121848ddf..bf6f7b1f6b18 100644 > --- a/mm/kasan/Makefile > +++ b/mm/kasan/Makefile > @@ -15,14 +15,19 @@ CFLAGS_REMOVE_tags_report.o = $(CC_FLAGS_FTRACE) > > # 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_CONFLICT := $(call cc-option, -fno-conserve-stack) > +CC_FLAGS_KASAN_CONFLICT += $(call cc-option, -fno-stack-protector) > +# Disable branch tracing to avoid recursion. > +CC_FLAGS_KASAN_CONFLICT += -DDISABLE_BRANCH_PROFILING Note that maybe CC_FLAGS_KASAN_RUNTIME could be a better name, because other flags added in future might not be conflict-related. But until that future, it doesn't really matter. > +CFLAGS_common.o := $(CC_FLAGS_KASAN_CONFLICT) > +CFLAGS_generic.o := $(CC_FLAGS_KASAN_CONFLICT) > +CFLAGS_generic_report.o := $(CC_FLAGS_KASAN_CONFLICT) > +CFLAGS_init.o := $(CC_FLAGS_KASAN_CONFLICT) > +CFLAGS_quarantine.o := $(CC_FLAGS_KASAN_CONFLICT) > +CFLAGS_report.o := $(CC_FLAGS_KASAN_CONFLICT) > +CFLAGS_tags.o := $(CC_FLAGS_KASAN_CONFLICT) > +CFLAGS_tags_report.o := $(CC_FLAGS_KASAN_CONFLICT) > > obj-$(CONFIG_KASAN) := common.o init.o report.o > obj-$(CONFIG_KASAN_GENERIC) += generic.o generic_report.o quarantine.o > -- > 2.27.0.rc0.183.gde8f92d652-goog > > -- > You received this message because you are subscribed to the Google Groups "kasan-dev" group. > To unsubscribe from this group and stop receiving emails from it, send an email to kasan-dev+unsubscribe@xxxxxxxxxxxxxxxx. > To view this discussion on the web visit https://groups.google.com/d/msgid/kasan-dev/ced83584eec86a1a9ce264013cf6c0da5e0add6a.1590686292.git.andreyknvl%40google.com.
