efi: avoid fortify checks in EFI stub

This avoids CONFIG_FORTIFY_SOURCE from being enabled during the EFI stub
build, as adding a panic() implementation may not work well.  This can
be adjusted in the future.

Link: http://lkml.kernel.org/r/1497903987-21002-2-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Suggested-by: Daniel Micay <danielmicay@gmail.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index f7425960f6a57d4d4048e905d4d6b101b333c114..37e24f525162e10d95e625953773783349ee1316 100644 (file)
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -17,6 +17,7 @@ cflags-$(CONFIG_ARM)          := $(subst -pg,,$(KBUILD_CFLAGS)) \
 cflags-$(CONFIG_EFI_ARMSTUB)   += -I$(srctree)/scripts/dtc/libfdt
 
 KBUILD_CFLAGS                  := $(cflags-y) -DDISABLE_BRANCH_PROFILING \
+                                  -D__NO_FORTIFY \
                                   $(call cc-option,-ffreestanding) \
                                   $(call cc-option,-fno-stack-protector)