[PATCH 5/6] Disable stack protection for decompressor/stub

[Roy Franz]

The ARM decompressor/EFI stub do not implement the functions
(__stack_chk_guard_setup, etc) that are required for support of
stack protection.  The actual enablement of stack protection is
controlled by heuristics in GCC, which the code added for the EFI
stub triggers when CONFIG_STACKPROTECTOR is set.  Even with
CONFIG_STACKPROTECTOR set, the decompressor was not compiled
with stack protection actually enabled. Adding -fno-stack-protector
to the decompressor/stub build keeps it building without stack
protection as it has always been built.
The x86 decompressor/stub is also build with -fno-stack-protector.

Signed-off-by: Roy Franz <roy.franz at linaro.org>
---
 arch/arm/boot/compressed/Makefile |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile
index 5fad8bd..551dbf9 100644
--- a/arch/arm/boot/compressed/Makefile
+++ b/arch/arm/boot/compressed/Makefile
@@ -136,7 +136,7 @@ ORIG_CFLAGS := $(KBUILD_CFLAGS)
 KBUILD_CFLAGS = $(subst -pg, , $(ORIG_CFLAGS))
 endif
 
-ccflags-y := -fpic -mno-single-pic-base -fno-builtin -I$(obj)
+ccflags-y := -fpic -mno-single-pic-base -fno-builtin -fno-stack-protector -I$(obj)
 asflags-y := -DZIMAGE
 
 # Supply kernel BSS size to the decompressor via a linker symbol.
-- 
1.7.10.4