With 8f91869766c0 ("x86/build: Fix stack alignment for CLang") cc-option
is only used to determine the name of the stack alignment option supported
by the compiler, but not to verify that the actual parameter <option>=N is
valid in combination with the other CFLAGS. This causes problems with older
gcc versions which only support stack alignment on a boundary of 16 bytes
or higher.
Also use (__)cc_option to add the stack alignment option to CFLAGS to
make sure only valid options are added.
Fixes: 8f91869766c0 ("x86/build: Fix stack alignment for CLang")
Signed-off-by: Matthias Kaehlcke <[email protected]>
---
arch/x86/Makefile | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 65ed359eb904..9231bbfae670 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -38,7 +38,7 @@ REALMODE_CFLAGS := $(M16_CFLAGS) -g -Os -D__KERNEL__ \
REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS),
-ffreestanding)
REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS),
-fno-stack-protector)
-REALMODE_CFLAGS += $(cc_stack_align4)
+REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS),
$(cc_stack_align4))
export REALMODE_CFLAGS
# BITS is used as extension for files which are available in a 32 bit
@@ -78,7 +78,7 @@ ifeq ($(CONFIG_X86_32),y)
# Align the stack to the register width instead of using the default
# alignment of 16 bytes. This reduces stack usage and the number of
# alignment instructions.
- KBUILD_CFLAGS += $(cc_stack_align4)
+ KBUILD_CFLAGS += $(call cc-option,$(cc_stack_align4))
# Disable unit-at-a-time mode on pre-gcc-4.0 compilers, it makes gcc
use
# a lot more stack due to the lack of sharing of stacklots:
@@ -117,7 +117,7 @@ else
# default alignment which keep the stack *mis*aligned.
# Furthermore an alignment to the register width reduces stack usage
# and the number of alignment instructions.
- KBUILD_CFLAGS += $(cc_stack_align8)
+ KBUILD_CFLAGS += $(call cc-option,$(cc_stack_align8))
# Use -mskip-rax-setup if supported.
KBUILD_CFLAGS += $(call cc-option,-mskip-rax-setup)
--
2.14.1.480.gb18f417b89-goog
