stackprotector: update make rules
Impact: no default -fno-stack-protector if stackp is enabled, cleanup
Stackprotector make rules had the following problems.
* cc support test and warning are scattered across makefile and
kernel/panic.c.
* -fno-stack-protector was always added regardless of configuration.
Update such that cc support test and warning are contained in makefile
and -fno-stack-protector is added iff stackp is turned off. While at
it, prepare for 32bit support.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index cacee98..ab48ab4 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -70,14 +70,17 @@
# this works around some issues with generating unwind tables in older gccs
# newer gccs do it by default
KBUILD_CFLAGS += -maccumulate-outgoing-args
+endif
- stackp := $(CONFIG_SHELL) $(srctree)/scripts/gcc-x86_64-has-stack-protector.sh
- stackp-$(CONFIG_CC_STACKPROTECTOR) := $(shell $(stackp) \
- "$(CC)" "-fstack-protector -DGCC_HAS_SP" )
- stackp-$(CONFIG_CC_STACKPROTECTOR_ALL) += $(shell $(stackp) \
- "$(CC)" -fstack-protector-all )
-
- KBUILD_CFLAGS += $(stackp-y)
+ifdef CONFIG_CC_STACKPROTECTOR
+ cc_has_sp := $(srctree)/scripts/gcc-x86_$(BITS)-has-stack-protector.sh
+ ifeq ($(shell $(CONFIG_SHELL) $(cc_has_sp) $(CC)),y)
+ stackp-y := -fstack-protector
+ stackp-$(CONFIG_CC_STACKPROTECTOR_ALL) += -fstack-protector-all
+ KBUILD_CFLAGS += $(stackp-y)
+ else
+ $(warning stack protector enabled but no compiler support)
+ endif
endif
# Stackpointer is addressed different for 32 bit and 64 bit x86