Linus,
Please pull the latest x86-build-for-linus git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-build-for-linus
# HEAD: 9e8730b178a2472fca3123e909d6e69cc8127778 x86/build: Use cc-option to
validate stack alignment parameter
More Clang support related fixes.
Thanks,
Ingo
------------------>
Cao jin (1):
x86/build: Drop unused mflags-y
Matthias Kaehlcke (2):
x86/build: Fix stack alignment for CLang
x86/build: Use cc-option to validate stack alignment parameter
arch/x86/Makefile | 17 ++++++++---------
1 file changed, 8 insertions(+), 9 deletions(-)
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 1e902f926be3..6276572259c8 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -14,9 +14,11 @@ endif
# For gcc stack alignment is specified with -mpreferred-stack-boundary,
# clang has the option -mstack-alignment for that purpose.
ifneq ($(call cc-option, -mpreferred-stack-boundary=4),)
- cc_stack_align_opt := -mpreferred-stack-boundary
-else ifneq ($(call cc-option, -mstack-alignment=4),)
- cc_stack_align_opt := -mstack-alignment
+ cc_stack_align4 := -mpreferred-stack-boundary=2
+ cc_stack_align8 := -mpreferred-stack-boundary=3
+else ifneq ($(call cc-option, -mstack-alignment=16),)
+ cc_stack_align4 := -mstack-alignment=4
+ cc_stack_align8 := -mstack-alignment=8
endif
# How to compile the 16-bit code. Note we always compile for -march=i386;
@@ -36,7 +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 += $(call __cc-option, $(CC), $(REALMODE_CFLAGS),
$(cc_stack_align_opt)=2)
+REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS),
$(cc_stack_align4))
export REALMODE_CFLAGS
# BITS is used as extension for files which are available in a 32 bit
@@ -76,7 +78,7 @@ ifeq ($(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 += $(call cc-option,$(cc_stack_align_opt)=2)
+ 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:
@@ -115,7 +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 += $(call cc-option,$(cc_stack_align_opt)=3)
+ KBUILD_CFLAGS += $(call cc-option,$(cc_stack_align8))
# Use -mskip-rax-setup if supported.
KBUILD_CFLAGS += $(call cc-option,-mskip-rax-setup)
@@ -232,9 +234,6 @@ KBUILD_CFLAGS += -Wno-sign-compare
#
KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
-KBUILD_CFLAGS += $(mflags-y)
-KBUILD_AFLAGS += $(mflags-y)
-
archscripts: scripts_basic
$(Q)$(MAKE) $(build)=arch/x86/tools relocs
