kbuild: enable 'make CFLAGS=...' to add additional options to CC

The variable CFLAGS is a wellknown variable and the usage by
kbuild may result in unexpected behaviour.
On top of that several people over time has asked for a way to
pass in additional flags to gcc.

This patch replace use of CFLAGS with KBUILD_CFLAGS all over the
tree and enabling one to use:
make CFLAGS=...
to specify additional gcc commandline options.

One usecase is when trying to find gcc bugs but other
use cases has been requested too.

Patch was tested on following architectures:
alpha, arm, i386, x86_64, mips, sparc, sparc64, ia64, m68k

Test was simple to do a defconfig build, apply the patch and check
that nothing got rebuild.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

Documentation/kbuild/makefiles.txt

@@ -294,7 +294,7 @@ more details, with real examples.
 
 
 	This variable is necessary because the top Makefile owns the
-	variable $(CFLAGS) and uses it for compilation flags for the
+	variable $(KBUILD_CFLAGS) and uses it for compilation flags for the
 	entire tree.
 
 	$(EXTRA_AFLAGS) is a similar string for per-directory options
@@ -437,6 +437,7 @@ more details, with real examples.
 	-march=pentium-mmx if supported by $(CC), otherwise -march=i586.
 	The second argument to cc-option is optional, and if omitted,
 	cflags-y will be assigned no value if first option is not supported.
+	Note: cc-option uses KBUILD_CFLAGS for $(CC) options
 
    cc-option-yn
 	cc-option-yn is used to check if gcc supports a given option
@@ -452,6 +453,7 @@ more details, with real examples.
 	option. When $(biarch) equals 'y', the expanded variables $(aflags-y)
 	and $(cflags-y) will be assigned the values -a32 and -m32,
 	respectively.
+	Note: cc-option-yn uses KBUILD_CFLAGS for $(CC) options
 
     cc-option-align
 	gcc versions >= 3.0 changed the type of options used to specify
@@ -463,10 +465,11 @@ more details, with real examples.
 		cc-option-align = -falign
 
 	Example:
-		CFLAGS += $(cc-option-align)-functions=4
+		KBUILD_CFLAGS += $(cc-option-align)-functions=4
 
 	In the above example, the option -falign-functions=4 is used for
 	gcc >= 3.00. For gcc < 3.00, -malign-functions=4 is used.
+	Note: cc-option-align uses KBUILD_CFLAGS for $(CC) options
 
     cc-version
 	cc-version returns a numerical version of the $(CC) compiler version.
@@ -825,17 +828,17 @@ When kbuild executes, the following steps are followed (roughly):
 		#arch/sparc64/Makefile
 		AFLAGS += -m64 -mcpu=ultrasparc
 
-    CFLAGS		$(CC) compiler flags
+    KBUILD_CFLAGS		$(CC) compiler flags
 
 	Default value - see top level Makefile
 	Append or modify as required per architecture.
 
-	Often, the CFLAGS variable depends on the configuration.
+	Often, the KBUILD_CFLAGS variable depends on the configuration.
 
 	Example:
 		#arch/i386/Makefile
 		cflags-$(CONFIG_M386) += -march=i386
-		CFLAGS += $(cflags-y)
+		KBUILD_CFLAGS += $(cflags-y)
 
 	Many arch Makefiles dynamically run the target C compiler to
 	probe supported options:
@@ -847,7 +850,7 @@ When kbuild executes, the following steps are followed (roughly):
 						-march=pentium2,-march=i686)
 		...
 		# Disable unit-at-a-time mode ...
-		CFLAGS += $(call cc-option,-fno-unit-at-a-time)
+		KBUILD_CFLAGS += $(call cc-option,-fno-unit-at-a-time)
 		...
 
 

Makefile

@@ -320,7 +320,7 @@ LINUXINCLUDE    := -Iinclude \
 
 CPPFLAGS        := -D__KERNEL__ $(LINUXINCLUDE)
 
-CFLAGS          := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
+KBUILD_CFLAGS   := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
 		   -fno-strict-aliasing -fno-common \
 		   -Werror-implicit-function-declaration
 AFLAGS          := -D__ASSEMBLY__
@@ -335,7 +335,7 @@ export CPP AR NM STRIP OBJCOPY OBJDUMP MAKE AWK GENKSYMS PERL UTS_MACHINE
 export HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS
 
 export CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGS
-export CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
+export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
 export AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
 
 # When compiling out-of-tree modules, put MODVERDIR in the module
@@ -492,36 +492,36 @@ endif # $(dot-config)
 all: vmlinux
 
 ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
-CFLAGS		+= -Os
+KBUILD_CFLAGS	+= -Os
 else
-CFLAGS		+= -O2
+KBUILD_CFLAGS	+= -O2
 endif
 
 include $(srctree)/arch/$(ARCH)/Makefile
 
 ifdef CONFIG_FRAME_POINTER
-CFLAGS		+= -fno-omit-frame-pointer -fno-optimize-sibling-calls
+KBUILD_CFLAGS	+= -fno-omit-frame-pointer -fno-optimize-sibling-calls
 else
-CFLAGS		+= -fomit-frame-pointer
+KBUILD_CFLAGS	+= -fomit-frame-pointer
 endif
 
 ifdef CONFIG_DEBUG_INFO
-CFLAGS		+= -g
+KBUILD_CFLAGS	+= -g
 AFLAGS		+= -gdwarf-2
 endif
 
 # Force gcc to behave correct even for buggy distributions
-CFLAGS          += $(call cc-option, -fno-stack-protector)
+KBUILD_CFLAGS         += $(call cc-option, -fno-stack-protector)
 
 # arch Makefile may override CC so keep this after arch Makefile is included
 NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
 CHECKFLAGS     += $(NOSTDINC_FLAGS)
 
 # warn about C99 declaration after statement
-CFLAGS += $(call cc-option,-Wdeclaration-after-statement,)
+KBUILD_CFLAGS += $(call cc-option,-Wdeclaration-after-statement,)
 
 # disable pointer signed / unsigned warnings in gcc 4.0
-CFLAGS += $(call cc-option,-Wno-pointer-sign,)
+KBUILD_CFLAGS += $(call cc-option,-Wno-pointer-sign,)
 
 # Use --build-id when available.
 LDFLAGS_BUILD_ID = $(patsubst -Wl$(comma)%,%,\

arch/alpha/Makefile

@@ -84,7 +84,7 @@ endif
 # For TSUNAMI, we must have the assembler not emulate our instructions.
 # The same is true for IRONGATE, POLARIS, PYXIS.
 # BWX is most important, but we don't really want any emulation ever.
-CFLAGS += $(cflags-y) -Wa,-mev6
+KBUILD_CFLAGS += $(cflags-y) -Wa,-mev6
 
 head-y := arch/alpha/kernel/head.o
 

arch/alpha/kernel/Makefile

@@ -3,7 +3,7 @@
 #
 
 extra-y		:= head.o vmlinux.lds
-EXTRA_AFLAGS	:= $(CFLAGS)
+EXTRA_AFLAGS	:= $(KBUILD_CFLAGS)
 EXTRA_CFLAGS	:= -Werror -Wno-sign-compare
 
 obj-y    := entry.o traps.o process.o init_task.o osf_sys.o irq.o \

arch/alpha/lib/Makefile

@@ -2,7 +2,7 @@
 # Makefile for alpha-specific library files..
 #
 
-EXTRA_AFLAGS := $(CFLAGS)
+EXTRA_AFLAGS := $(KBUILD_CFLAGS)
 EXTRA_CFLAGS := -Werror
 
 # Many of these routines have implementations tuned for ev6.

arch/arm/Makefile

@@ -14,9 +14,9 @@ LDFLAGS_vmlinux	:=-p --no-undefined -X
 CPPFLAGS_vmlinux.lds = -DTEXT_OFFSET=$(TEXT_OFFSET)
 OBJCOPYFLAGS	:=-O binary -R .note -R .comment -S
 GZFLAGS		:=-9
-#CFLAGS		+=-pipe
+#KBUILD_CFLAGS	+=-pipe
 # Explicitly specifiy 32-bit ARM ISA since toolchain default can be -mthumb:
-CFLAGS		+=$(call cc-option,-marm,)
+KBUILD_CFLAGS	+=$(call cc-option,-marm,)
 
 # Do not use arch/arm/defconfig - it's always outdated.
 # Select a platform tht is kept up-to-date
@@ -28,7 +28,7 @@ MMUEXT		:= -nommu
 endif
 
 ifeq ($(CONFIG_FRAME_POINTER),y)
-CFLAGS		+=-fno-omit-frame-pointer -mapcs -mno-sched-prolog
+KBUILD_CFLAGS	+=-fno-omit-frame-pointer -mapcs -mno-sched-prolog
 endif
 
 ifeq ($(CONFIG_CPU_BIG_ENDIAN),y)
@@ -85,7 +85,7 @@ CFLAGS_ABI	:=$(call cc-option,-mapcs-32,-mabi=apcs-gnu) $(call cc-option,-mno-th
 endif
 
 # Need -Uarm for gcc < 3.x
-CFLAGS		+=$(CFLAGS_ABI) $(arch-y) $(tune-y) $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,)) -msoft-float -Uarm
+KBUILD_CFLAGS	+=$(CFLAGS_ABI) $(arch-y) $(tune-y) $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,)) -msoft-float -Uarm
 AFLAGS		+=$(CFLAGS_ABI) $(arch-y) $(tune-y) -msoft-float
 
 CHECKFLAGS	+= -D__arm__

arch/arm/boot/compressed/Makefile

@@ -87,7 +87,7 @@ ifneq ($(PARAMS_PHYS),)
 LDFLAGS_vmlinux += --defsym params_phys=$(PARAMS_PHYS)
 endif
 LDFLAGS_vmlinux += -p --no-undefined -X \
-	$(shell $(CC) $(CFLAGS) --print-libgcc-file-name) -T
+	$(shell $(CC) $(KBUILD_CFLAGS) --print-libgcc-file-name) -T
 
 # Don't allow any static data in misc.o, which
 # would otherwise mess up our GOT table

arch/avr32/Makefile

@@ -11,14 +11,14 @@ all: uImage vmlinux.elf
 
 KBUILD_DEFCONFIG	:= atstk1002_defconfig
 
-CFLAGS		+= -pipe -fno-builtin -mno-pic
+KBUILD_CFLAGS	+= -pipe -fno-builtin -mno-pic
 AFLAGS		+= -mrelax -mno-pic
 CFLAGS_MODULE	+= -mno-relax
 LDFLAGS_vmlinux	+= --relax
 
 cpuflags-$(CONFIG_CPU_AT32AP7000)	+= -mcpu=ap7000
 
-CFLAGS		+= $(cpuflags-y)
+KBUILD_CFLAGS	+= $(cpuflags-y)
 AFLAGS		+= $(cpuflags-y)
 
 CHECKFLAGS	+= -D__avr32__ -D__BIG_ENDIAN

arch/blackfin/Makefile

@@ -53,7 +53,7 @@ rev-$(CONFIG_BF_REV_0_5)  := 0.5
 rev-$(CONFIG_BF_REV_NONE) := none
 rev-$(CONFIG_BF_REV_ANY)  := any
 
-CFLAGS += -mcpu=$(cpu-y)-$(rev-y)
+KBUILD_CFLAGS += -mcpu=$(cpu-y)-$(rev-y)
 AFLAGS += -mcpu=$(cpu-y)-$(rev-y)
 
 head-y   := arch/$(ARCH)/mach-$(MACHINE)/head.o arch/$(ARCH)/kernel/init_task.o

arch/cris/Makefile

@@ -31,16 +31,16 @@ OBJCOPYFLAGS := -O binary -R .note -R .comment -S
 CPPFLAGS_vmlinux.lds = -DDRAM_VIRTUAL_BASE=0x$(CONFIG_ETRAX_DRAM_VIRTUAL_BASE)
 AFLAGS += -mlinux
 
-CFLAGS := $(CFLAGS) -mlinux -march=$(arch-y) -pipe
+KBUILD_CFLAGS += -mlinux -march=$(arch-y) -pipe
 
 ifdef CONFIG_FRAME_POINTER
-CFLAGS := $(subst -fomit-frame-pointer,,$(CFLAGS)) -g
-CFLAGS += -fno-omit-frame-pointer
+KBUILD_CFLAGS := $(subst -fomit-frame-pointer,,$(KBUILD_CFLAGS)) -g
+KBUILD_CFLAGS += -fno-omit-frame-pointer
 endif
 
 head-y := arch/$(ARCH)/$(SARCH)/kernel/head.o
 
-LIBGCC = $(shell $(CC) $(CFLAGS) -print-file-name=libgcc.a)
+LIBGCC = $(shell $(CC) $(KBUILD_CFLAGS) -print-file-name=libgcc.a)
 
 core-y		+= arch/$(ARCH)/kernel/ arch/$(ARCH)/mm/
 core-y		+= arch/$(ARCH)/$(SARCH)/kernel/ arch/$(ARCH)/$(SARCH)/mm/

arch/frv/Makefile

@@ -39,13 +39,13 @@ endif
 ARCHMODFLAGS	+= -G0 -mlong-calls
 
 ifdef CONFIG_GPREL_DATA_8
-CFLAGS		+= -G8
+KBUILD_CFLAGS	+= -G8
 else
 ifdef CONFIG_GPREL_DATA_4
-CFLAGS		+= -G4
+KBUILD_CFLAGS	+= -G4
 else
 ifdef CONFIG_GPREL_DATA_NONE
-CFLAGS		+= -G0
+KBUILD_CFLAGS	+= -G0
 endif
 endif
 endif
@@ -53,25 +53,25 @@ endif
 #LDFLAGS_vmlinux	:= -Map linkmap.txt
 
 ifdef CONFIG_GC_SECTIONS
-CFLAGS		+= -ffunction-sections -fdata-sections
+KBUILD_CFLAGS	+= -ffunction-sections -fdata-sections
 LINKFLAGS	+= --gc-sections
 endif
 
 ifndef CONFIG_FRAME_POINTER
-CFLAGS		+= -mno-linked-fp
+KBUILD_CFLAGS	+= -mno-linked-fp
 endif
 
 ifdef CONFIG_CPU_FR451_COMPILE
-CFLAGS		+= -mcpu=fr450
+KBUILD_CFLAGS	+= -mcpu=fr450
 AFLAGS		+= -mcpu=fr450
 ASFLAGS		+= -mcpu=fr450
 else
 ifdef CONFIG_CPU_FR551_COMPILE
-CFLAGS		+= -mcpu=fr550
+KBUILD_CFLAGS	+= -mcpu=fr550
 AFLAGS		+= -mcpu=fr550
 ASFLAGS		+= -mcpu=fr550
 else
-CFLAGS		+= -mcpu=fr400
+KBUILD_CFLAGS	+= -mcpu=fr400
 AFLAGS		+= -mcpu=fr400
 ASFLAGS		+= -mcpu=fr400
 endif
@@ -80,15 +80,15 @@ endif
 # pretend the kernel is going to run on an FR400 with no media-fp unit
 # - reserve CC3 for use with atomic ops
 # - all the extra registers are dealt with only at context switch time
-CFLAGS		+= -mno-fdpic -mgpr-32 -msoft-float -mno-media
-CFLAGS		+= -ffixed-fcc3 -ffixed-cc3 -ffixed-gr15 -ffixed-icc2
+KBUILD_CFLAGS	+= -mno-fdpic -mgpr-32 -msoft-float -mno-media
+KBUILD_CFLAGS	+= -ffixed-fcc3 -ffixed-cc3 -ffixed-gr15 -ffixed-icc2
 AFLAGS		+= -mno-fdpic
 ASFLAGS		+= -mno-fdpic
 
 # make sure the .S files get compiled with debug info
 # and disable optimisations that are unhelpful whilst debugging
 ifdef CONFIG_DEBUG_INFO
-#CFLAGS		+= -O1
+#KBUILD_CFLAGS	+= -O1
 AFLAGS		+= -Wa,--gdwarf2
 ASFLAGS		+= -Wa,--gdwarf2
 endif

arch/h8300/Makefile

@@ -30,16 +30,16 @@ ldflags-$(CONFIG_CPU_H8300H)	:= -mh8300helf
 cflags-$(CONFIG_CPU_H8S)	:= -ms
 ldflags-$(CONFIG_CPU_H8S)	:= -mh8300self
 
-CFLAGS += $(cflags-y)
-CFLAGS += -mint32 -fno-builtin
-CFLAGS += -g
-CFLAGS += -D__linux__
-CFLAGS += -DUTS_SYSNAME=\"uClinux\"
+KBUILD_CFLAGS += $(cflags-y)
+KBUILD_CFLAGS += -mint32 -fno-builtin
+KBUILD_CFLAGS += -g
+KBUILD_CFLAGS += -D__linux__
+KBUILD_CFLAGS += -DUTS_SYSNAME=\"uClinux\"
 AFLAGS += -DPLATFORM=$(PLATFORM) -DMODEL=$(MODEL) $(cflags-y)
 LDFLAGS += $(ldflags-y)
 
 CROSS_COMPILE = h8300-elf-
-LIBGCC := $(shell $(CROSS-COMPILE)$(CC) $(CFLAGS) -print-libgcc-file-name)
+LIBGCC := $(shell $(CROSS-COMPILE)$(CC) $(KBUILD_CFLAGS) -print-libgcc-file-name)
 
 head-y := arch/$(ARCH)/platform/$(PLATFORM)/$(BOARD)/crt0_$(MODEL).o
 

arch/i386/Makefile

@@ -34,10 +34,10 @@ LDFLAGS_vmlinux := --emit-relocs
 endif
 CHECKFLAGS	+= -D__i386__
 
-CFLAGS += -pipe -msoft-float -mregparm=3 -freg-struct-return
+KBUILD_CFLAGS += -pipe -msoft-float -mregparm=3 -freg-struct-return
 
 # prevent gcc from keeping the stack 16 byte aligned
-CFLAGS += $(call cc-option,-mpreferred-stack-boundary=2)
+KBUILD_CFLAGS += $(call cc-option,-mpreferred-stack-boundary=2)
 
 # CPU-specific tuning. Anything which can be shared with UML should go here.
 include $(srctree)/arch/i386/Makefile.cpu
@@ -51,7 +51,7 @@ cflags-y += -maccumulate-outgoing-args
 
 # 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:
-CFLAGS				+= $(shell if [ $(call cc-version) -lt 0400 ] ; then echo $(call cc-option,-fno-unit-at-a-time); fi ;)
+KBUILD_CFLAGS += $(shell if [ $(call cc-version) -lt 0400 ] ; then echo $(call cc-option,-fno-unit-at-a-time); fi ;)
 
 # do binutils support CFI?
 cflags-y += $(call as-instr,.cfi_startproc\n.cfi_rel_offset esp${comma}0\n.cfi_endproc,-DCONFIG_AS_CFI=1,)
@@ -61,7 +61,7 @@ AFLAGS += $(call as-instr,.cfi_startproc\n.cfi_rel_offset esp${comma}0\n.cfi_end
 cflags-y += $(call as-instr,.cfi_startproc\n.cfi_signal_frame\n.cfi_endproc,-DCONFIG_AS_CFI_SIGNAL_FRAME=1,)
 AFLAGS += $(call as-instr,.cfi_startproc\n.cfi_signal_frame\n.cfi_endproc,-DCONFIG_AS_CFI_SIGNAL_FRAME=1,)
 
-CFLAGS += $(cflags-y)
+KBUILD_CFLAGS += $(cflags-y)
 
 # Default subarch .c files
 mcore-y  := arch/x86/mach-default
@@ -116,7 +116,7 @@ drivers-$(CONFIG_OPROFILE)		+= arch/x86/oprofile/
 drivers-$(CONFIG_PM)			+= arch/x86/power/
 drivers-$(CONFIG_FB)                    += arch/x86/video/
 
-CFLAGS += $(mflags-y)
+KBUILD_CFLAGS += $(mflags-y)
 AFLAGS += $(mflags-y)
 
 boot := arch/x86/boot

arch/ia64/Makefile

@@ -44,7 +44,7 @@ ifeq ($(call cc-version),0304)
 	cflags-$(CONFIG_MCKINLEY)	+= -mtune=mckinley
 endif
 
-CFLAGS += $(cflags-y)
+KBUILD_CFLAGS += $(cflags-y)
 head-y := arch/ia64/kernel/head.o arch/ia64/kernel/init_task.o
 
 libs-y				+= arch/ia64/lib/

arch/m32r/Makefile

@@ -9,7 +9,7 @@ LDFLAGS		:=
 OBJCOPYFLAGS	:= -O binary -R .note -R .comment -S
 LDFLAGS_vmlinux	:=
 
-CFLAGS += -pipe -fno-schedule-insns
+KBUILD_CFLAGS += -pipe -fno-schedule-insns
 CFLAGS_KERNEL += -mmodel=medium
 CFLAGS_MODULE += -mmodel=large
 
@@ -24,14 +24,14 @@ endif
 cflags-$(CONFIG_ISA_M32R)	+= -DNO_FPU
 aflags-$(CONFIG_ISA_M32R)	+= -DNO_FPU -O2 -Wa,-no-bitinst
 
-CFLAGS += $(cflags-y)
+KBUILD_CFLAGS += $(cflags-y)
 AFLAGS += $(aflags-y)
 
 CHECKFLAGS	+= -D__m32r__ -D__BIG_ENDIAN__=1
 
 head-y	:= arch/m32r/kernel/head.o arch/m32r/kernel/init_task.o
 
-LIBGCC	:= $(shell $(CC) $(CFLAGS) -print-libgcc-file-name)
+LIBGCC	:= $(shell $(CC) $(KBUILD_CFLAGS) -print-libgcc-file-name)
 
 libs-y	+= arch/m32r/lib/ $(LIBGCC)
 core-y	+= arch/m32r/kernel/	\

arch/m68k/Makefile

@@ -32,18 +32,18 @@ endif
 CHECKFLAGS += -D__mc68000__
 
 # without -fno-strength-reduce the 53c7xx.c driver fails ;-(
-CFLAGS += -pipe -fno-strength-reduce -ffixed-a2
+KBUILD_CFLAGS += -pipe -fno-strength-reduce -ffixed-a2
 
 # enable processor switch if compiled only for a single cpu
 ifndef CONFIG_M68020
 ifndef CONFIG_M68030
 
 ifndef CONFIG_M68060
-CFLAGS := $(CFLAGS) -m68040
+KBUILD_CFLAGS += -m68040
 endif
 
 ifndef CONFIG_M68040
-CFLAGS := $(CFLAGS) -m68060
+KBUILD_CFLAGS += -m68060
 endif
 
 endif
@@ -52,7 +52,7 @@ endif
 ifdef CONFIG_KGDB
 # If configured for kgdb support, include debugging infos and keep the
 # frame pointer
-CFLAGS := $(subst -fomit-frame-pointer,,$(CFLAGS)) -g
+KBUILD_CFLAGS := $(subst -fomit-frame-pointer,,$(KBUILD_CFLAGS)) -g
 endif
 
 ifndef CONFIG_SUN3

arch/m68knommu/Makefile

@@ -104,9 +104,9 @@ cflags-$(CONFIG_M68360)		:= -m68332
 
 AFLAGS += $(cflags-y)
 
-CFLAGS += $(cflags-y)
-CFLAGS += -D__linux__
-CFLAGS += -DUTS_SYSNAME=\"uClinux\"
+KBUILD_CFLAGS += $(cflags-y)
+KBUILD_CFLAGS += -D__linux__
+KBUILD_CFLAGS += -DUTS_SYSNAME=\"uClinux\"
 
 head-y := arch/m68knommu/platform/$(cpuclass-y)/head.o
 

arch/mips/Makefile

@@ -609,13 +609,13 @@ ifdef CONFIG_64BIT
 endif
 
 AFLAGS		+= $(cflags-y)
-CFLAGS		+= $(cflags-y) \
+KBUILD_CFLAGS	+= $(cflags-y) \
 			-D"VMLINUX_LOAD_ADDRESS=$(load-y)"
 
 LDFLAGS			+= -m $(ld-emul)
 
 ifdef CONFIG_MIPS
-CHECKFLAGS += $(shell $(CC) $(CFLAGS) -dM -E -xc /dev/null | \
+CHECKFLAGS += $(shell $(CC) $(KBUILD_CFLAGS) -dM -E -xc /dev/null | \
 	egrep -vw '__GNUC_(|MINOR_|PATCHLEVEL_)_' | \
 	sed -e 's/^\#define /-D/' -e "s/ /='/" -e "s/$$/'/")
 ifdef CONFIG_64BIT
@@ -632,7 +632,7 @@ OBJCOPYFLAGS		+= --remove-section=.reginfo
 #
 
 CPPFLAGS_vmlinux.lds := \
-	$(CFLAGS) \
+	$(KBUILD_CFLAGS) \
 	-D"LOADADDR=$(load-y)" \
 	-D"JIFFIES=$(JIFFIES)" \
 	-D"DATAOFFSET=$(if $(dataoffset-y),$(dataoffset-y),0)"

arch/mips/kernel/Makefile

@@ -71,7 +71,7 @@ obj-$(CONFIG_PCSPEAKER)		+= pcspeaker.o
 obj-$(CONFIG_KEXEC)		+= machine_kexec.o relocate_kernel.o
 obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o
 
-CFLAGS_cpu-bugs64.o	= $(shell if $(CC) $(CFLAGS) -Wa,-mdaddi -c -o /dev/null -xc /dev/null >/dev/null 2>&1; then echo "-DHAVE_AS_SET_DADDI"; fi)
+CFLAGS_cpu-bugs64.o	= $(shell if $(CC) $(KBUILD_CFLAGS) -Wa,-mdaddi -c -o /dev/null -xc /dev/null >/dev/null 2>&1; then echo "-DHAVE_AS_SET_DADDI"; fi)
 
 obj-$(CONFIG_HAVE_STD_PC_SERIAL_PORT)	+= 8250-platform.o
 

arch/parisc/Makefile

@@ -63,7 +63,7 @@ cflags-$(CONFIG_PA8X00)		+= -march=2.0 -mschedule=8000
 
 head-y			:= arch/parisc/kernel/head.o 
 
-CFLAGS	+= $(cflags-y)
+KBUILD_CFLAGS	+= $(cflags-y)
 
 kernel-y			:= mm/ kernel/ math-emu/ kernel/init_task.o
 kernel-$(CONFIG_HPUX)		+= hpux/

arch/powerpc/Makefile

@@ -77,8 +77,8 @@ CFLAGS-$(CONFIG_PPC64)	:= -mminimal-toc -mtraceback=none  -mcall-aixdesc
 CFLAGS-$(CONFIG_PPC32)	:= -Iarch/$(ARCH) -ffixed-r2 -mmultiple
 CPPFLAGS	+= $(CPPFLAGS-y)
 AFLAGS		+= $(AFLAGS-y)
-CFLAGS		+= -msoft-float -pipe $(CFLAGS-y)
-CPP		= $(CC) -E $(CFLAGS)
+KBUILD_CFLAGS	+= -msoft-float -pipe $(CFLAGS-y)
+CPP		= $(CC) -E $(KBUILD_CFLAGS)
 
 CHECKFLAGS	+= -m$(CONFIG_WORD_SIZE) -D__powerpc__ -D__powerpc$(CONFIG_WORD_SIZE)__
 
@@ -88,35 +88,35 @@ GCC_BROKEN_VEC	:= $(shell if [ $(call cc-version) -lt 0400 ] ; then echo "y"; fi
 ifeq ($(CONFIG_POWER4_ONLY),y)
 ifeq ($(CONFIG_ALTIVEC),y)
 ifeq ($(GCC_BROKEN_VEC),y)
-	CFLAGS += $(call cc-option,-mcpu=970)
+	KBUILD_CFLAGS += $(call cc-option,-mcpu=970)
 else
-	CFLAGS += $(call cc-option,-mcpu=power4)
+	KBUILD_CFLAGS += $(call cc-option,-mcpu=power4)
 endif
 else
-	CFLAGS += $(call cc-option,-mcpu=power4)
+	KBUILD_CFLAGS += $(call cc-option,-mcpu=power4)
 endif
 else
-	CFLAGS += $(call cc-option,-mtune=power4)
+	KBUILD_CFLAGS += $(call cc-option,-mtune=power4)
 endif
 endif
 
 ifeq ($(CONFIG_TUNE_CELL),y)
-	CFLAGS += $(call cc-option,-mtune=cell)
+	KBUILD_CFLAGS += $(call cc-option,-mtune=cell)
 endif
 
 # No AltiVec instruction when building kernel
-CFLAGS += $(call cc-option,-mno-altivec)
+KBUILD_CFLAGS += $(call cc-option,-mno-altivec)
 
 # Enable unit-at-a-time mode when possible. It shrinks the
 # kernel considerably.
-CFLAGS += $(call cc-option,-funit-at-a-time)
+KBUILD_CFLAGS += $(call cc-option,-funit-at-a-time)
 
 # Never use string load/store instructions as they are
 # often slow when they are implemented at all
-CFLAGS		+= -mno-string
+KBUILD_CFLAGS		+= -mno-string
 
 ifeq ($(CONFIG_6xx),y)
-CFLAGS		+= -mcpu=powerpc
+KBUILD_CFLAGS		+= -mcpu=powerpc
 endif
 
 cpu-as-$(CONFIG_4xx)		+= -Wa,-m405
@@ -126,7 +126,7 @@ cpu-as-$(CONFIG_E500)		+= -Wa,-me500
 cpu-as-$(CONFIG_E200)		+= -Wa,-me200
 
 AFLAGS += $(cpu-as-y)
-CFLAGS += $(cpu-as-y)
+KBUILD_CFLAGS += $(cpu-as-y)
 
 head-y				:= arch/powerpc/kernel/head_$(CONFIG_WORD_SIZE).o
 head-$(CONFIG_8xx)		:= arch/powerpc/kernel/head_8xx.o

arch/ppc/Makefile

@@ -24,20 +24,20 @@ LDFLAGS_vmlinux	:= -Ttext $(KERNELLOAD) -Bstatic
 # The -Iarch/$(ARCH)/include is temporary while we are merging
 CPPFLAGS	+= -Iarch/$(ARCH) -Iarch/$(ARCH)/include
 AFLAGS		+= -Iarch/$(ARCH)
-CFLAGS		+= -Iarch/$(ARCH) -msoft-float -pipe \
+KBUILD_CFLAGS	+= -Iarch/$(ARCH) -msoft-float -pipe \
 		-ffixed-r2 -mmultiple
 
 # No AltiVec instruction when building kernel
-CFLAGS		+= $(call cc-option, -mno-altivec)
+KBUILD_CFLAGS	+= $(call cc-option, -mno-altivec)
 
-CPP		= $(CC) -E $(CFLAGS)
+CPP		= $(CC) -E $(KBUILD_CFLAGS)
 # Temporary hack until we have migrated to asm-powerpc
 LINUXINCLUDE    += -Iarch/$(ARCH)/include
 
 CHECKFLAGS	+= -D__powerpc__
 
 ifndef CONFIG_FSL_BOOKE
-CFLAGS		+= -mstring
+KBUILD_CFLAGS	+= -mstring
 endif
 
 cpu-as-$(CONFIG_4xx)		+= -Wa,-m405
@@ -46,7 +46,7 @@ cpu-as-$(CONFIG_E500)		+= -Wa,-me500
 cpu-as-$(CONFIG_E200)		+= -Wa,-me200
 
 AFLAGS += $(cpu-as-y)
-CFLAGS += $(cpu-as-y)
+KBUILD_CFLAGS += $(cpu-as-y)
 
 # Default to the common case.
 KBUILD_DEFCONFIG := common_defconfig

arch/s390/Makefile

@@ -15,7 +15,7 @@
 
 ifndef CONFIG_64BIT
 LDFLAGS		:= -m elf_s390
-CFLAGS		+= -m31
+KBUILD_CFLAGS	+= -m31
 AFLAGS		+= -m31
 UTS_MACHINE	:= s390
 STACK_SIZE	:= 8192
@@ -23,7 +23,7 @@ CHECKFLAGS	+= -D__s390__ -msize-long
 else
 LDFLAGS		:= -m elf64_s390
 MODFLAGS	+= -fpic -D__PIC__
-CFLAGS		+= -m64
+KBUILD_CFLAGS	+= -m64
 AFLAGS		+= -m64
 UTS_MACHINE	:= s390x
 STACK_SIZE	:= 16384
@@ -77,8 +77,8 @@ cflags-$(CONFIG_WARN_STACK) += -mwarn-dynamicstack
 cflags-$(CONFIG_WARN_STACK) += -mwarn-framesize=$(CONFIG_WARN_STACK_SIZE)
 endif
 
-CFLAGS		+= -mbackchain -msoft-float $(cflags-y)
-CFLAGS 		+= -pipe -fno-strength-reduce -Wno-sign-compare 
+KBUILD_CFLAGS	+= -mbackchain -msoft-float $(cflags-y)
+KBUILD_CFLAGS	+= -pipe -fno-strength-reduce -Wno-sign-compare
 AFLAGS		+= $(aflags-y)
 
 OBJCOPYFLAGS	:= -O binary

arch/sh/Makefile

@@ -91,12 +91,12 @@ LDFLAGS_vmlinux		+= --defsym 'jiffies=jiffies_64+4'
 LDFLAGS			+= -EB
 endif
 
-CFLAGS		+= -pipe $(cflags-y)
+KBUILD_CFLAGS		+= -pipe $(cflags-y)
 AFLAGS		+= $(cflags-y)
 
 head-y := arch/sh/kernel/head.o arch/sh/kernel/init_task.o
 
-LIBGCC := $(shell $(CC) $(CFLAGS) -print-libgcc-file-name)
+LIBGCC := $(shell $(CC) $(KBUILD_CFLAGS) -print-libgcc-file-name)
 
 core-y				+= arch/sh/kernel/ arch/sh/mm/
 core-$(CONFIG_SH_FPU_EMU)	+= arch/sh/math-emu/

arch/sh/boot/compressed/Makefile

@@ -21,7 +21,7 @@ IMAGE_OFFSET	:= $(shell /bin/bash -c 'printf "0x%08x" \
 			$(CONFIG_MEMORY_START) + \
 			$(CONFIG_BOOT_LINK_OFFSET)]')
 
-LIBGCC	:= $(shell $(CC) $(CFLAGS) -print-libgcc-file-name)
+LIBGCC	:= $(shell $(CC) $(KBUILD_CFLAGS) -print-libgcc-file-name)
 
 LDFLAGS_vmlinux := -Ttext $(IMAGE_OFFSET) -e startup -T $(obj)/../../kernel/vmlinux.lds
 

arch/sh64/Makefile

@@ -26,7 +26,7 @@ LDFLAGS			+= -EB  -mshelf32_linux
 endif
 
 # No requirements for endianess support from AFLAGS, 'as' always run through gcc
-CFLAGS		+= $(cpu-y)
+KBUILD_CFLAGS		+= $(cpu-y)
 
 LDFLAGS_vmlinux	+= --defsym phys_stext=_stext-$(CONFIG_CACHED_MEMORY_OFFSET) \
 		  --defsym phys_stext_shmedia=phys_stext+1 \
@@ -57,7 +57,7 @@ ifneq ($(machine-y),)
 core-y	+= arch/sh64/mach-$(machine-y)/
 endif
 
-LIBGCC := $(shell $(CC) $(CFLAGS) -print-libgcc-file-name)
+LIBGCC := $(shell $(CC) $(KBUILD_CFLAGS) -print-libgcc-file-name)
 libs-y	+= arch/$(ARCH)/lib/ $(LIBGCC)
 
 drivers-$(CONFIG_OPROFILE)	+= arch/sh64/oprofile/

arch/sparc/Makefile

@@ -8,15 +8,15 @@
 #
 
 #
-# Uncomment the first CFLAGS if you are doing kgdb source level
+# Uncomment the first KBUILD_CFLAGS if you are doing kgdb source level
 # debugging of the kernel to get the proper debugging information.
 
 AS              := $(AS) -32
 LDFLAGS		:= -m elf32_sparc
 CHECKFLAGS	+= -D__sparc__
 
-#CFLAGS := $(CFLAGS) -g -pipe -fcall-used-g5 -fcall-used-g7
-CFLAGS := $(CFLAGS) -m32 -pipe -mno-fpu -fcall-used-g5 -fcall-used-g7
+#KBUILD_CFLAGS += -g -pipe -fcall-used-g5 -fcall-used-g7
+KBUILD_CFLAGS += -m32 -pipe -mno-fpu -fcall-used-g5 -fcall-used-g7
 AFLAGS := $(AFLAGS) -m32
 
 #LDFLAGS_vmlinux = -N -Ttext 0xf0004000

arch/sparc64/Makefile

@@ -39,17 +39,17 @@ AS		:= $(AS) --undeclared-regs
 endif
 
 ifneq ($(NEW_GCC),y)
-  CFLAGS := $(CFLAGS) -pipe -mno-fpu -mtune=ultrasparc -mmedlow \
+  KBUILD_CFLAGS += -pipe -mno-fpu -mtune=ultrasparc -mmedlow \
 	    -ffixed-g4 -ffixed-g5 -fcall-used-g7 -Wno-sign-compare
 else
-  CFLAGS := $(CFLAGS) -m64 -pipe -mno-fpu -mcpu=ultrasparc -mcmodel=medlow \
+  KBUILD_CFLAGS += -m64 -pipe -mno-fpu -mcpu=ultrasparc -mcmodel=medlow \
 	    -ffixed-g4 -ffixed-g5 -fcall-used-g7 -Wno-sign-compare \
 	    $(CC_UNDECL)
   AFLAGS += -m64 -mcpu=ultrasparc $(CC_UNDECL)
 endif
 
 ifeq ($(CONFIG_MCOUNT),y)
-  CFLAGS := $(CFLAGS) -pg
+  KBUILD_CFLAGS += -pg
 endif
 
 head-y := arch/sparc64/kernel/head.o arch/sparc64/kernel/init_task.o

arch/um/Makefile

@@ -58,14 +58,14 @@ SYS_DIR		:= $(ARCH_DIR)/include/sysdep-$(SUBARCH)
 #
 # These apply to USER_CFLAGS to.
 
-CFLAGS += $(CFLAGS-y) -D__arch_um__ -DSUBARCH=\"$(SUBARCH)\"	\
+KBUILD_CFLAGS += $(CFLAGS-y) -D__arch_um__ -DSUBARCH=\"$(SUBARCH)\"	\
 	$(ARCH_INCLUDE) $(MODE_INCLUDE) -Dvmap=kernel_vmap	\
 	-Din6addr_loopback=kernel_in6addr_loopback
 
 AFLAGS += $(ARCH_INCLUDE)
 
 USER_CFLAGS = $(patsubst $(KERNEL_DEFINES),,$(patsubst -D__KERNEL__,,\
-	$(patsubst -I%,,$(CFLAGS)))) $(ARCH_INCLUDE) $(MODE_INCLUDE) \
+	$(patsubst -I%,,$(KBUILD_CFLAGS)))) $(ARCH_INCLUDE) $(MODE_INCLUDE) \
 	-D_FILE_OFFSET_BITS=64
 
 include $(srctree)/$(ARCH_DIR)/Makefile-$(SUBARCH)
@@ -75,14 +75,14 @@ include $(srctree)/$(ARCH_DIR)/Makefile-os-$(OS)
 
 # -Derrno=kernel_errno - This turns all kernel references to errno into
 # kernel_errno to separate them from the libc errno.  This allows -fno-common
-# in CFLAGS.  Otherwise, it would cause ld to complain about the two different
+# in KBUILD_CFLAGS.  Otherwise, it would cause ld to complain about the two different
 # errnos.
 # These apply to kernelspace only.
 
 KERNEL_DEFINES = -Derrno=kernel_errno -Dsigprocmask=kernel_sigprocmask \
 	-Dmktime=kernel_mktime $(ARCH_KERNEL_DEFINES)
-CFLAGS += $(KERNEL_DEFINES)
-CFLAGS += $(call cc-option,-fno-unit-at-a-time,)
+KBUILD_CFLAGS += $(KERNEL_DEFINES)
+KBUILD_CFLAGS += $(call cc-option,-fno-unit-at-a-time,)
 
 # These are needed for clean and mrproper, since in that case .config is not
 # included; the values here are meaningless

arch/um/Makefile-i386

@@ -15,7 +15,7 @@ OBJCOPYFLAGS  		:= -O binary -R .note -R .comment -S
 
 ifeq ("$(origin SUBARCH)", "command line")
 ifneq ("$(shell uname -m | sed -e s/i.86/i386/)", "$(SUBARCH)")
-CFLAGS			+= $(call cc-option,-m32)
+KBUILD_CFLAGS		+= $(call cc-option,-m32)
 AFLAGS			+= $(call cc-option,-m32)
 LINK-y			+= $(call cc-option,-m32)
 UML_OBJCOPYFLAGS	+= -F $(ELF_FORMAT)
@@ -36,4 +36,4 @@ cflags-y += $(call cc-option,-mpreferred-stack-boundary=2)
 # an unresolved reference.
 cflags-y += -ffreestanding
 
-CFLAGS += $(cflags-y)
+KBUILD_CFLAGS += $(cflags-y)

arch/um/Makefile-os-Linux

@@ -5,4 +5,4 @@
 
 # To get a definition of F_SETSIG
 USER_CFLAGS += -D_GNU_SOURCE -D_LARGEFILE64_SOURCE
-CFLAGS += -D_LARGEFILE64_SOURCE
+KBUILD_CFLAGS += -D_LARGEFILE64_SOURCE

arch/um/Makefile-x86_64

@@ -9,7 +9,7 @@ _extra_flags_ = -fno-builtin -m64
 #We #undef __x86_64__ for kernelspace, not for userspace where
 #it's needed for headers to work!
 ARCH_KERNEL_DEFINES = -U__$(SUBARCH)__
-CFLAGS += $(_extra_flags_)
+KBUILD_CFLAGS += $(_extra_flags_)
 
 CHECKFLAGS  += -m64
 AFLAGS += -m64

arch/um/drivers/Makefile

@@ -17,7 +17,7 @@ ubd-objs := ubd_kern.o ubd_user.o
 port-objs := port_kern.o port_user.o
 harddog-objs := harddog_kern.o harddog_user.o
 
-LDFLAGS_pcap.o := -r $(shell $(CC) $(CFLAGS) -print-file-name=libpcap.a)
+LDFLAGS_pcap.o := -r $(shell $(CC) $(KBUILD_CFLAGS) -print-file-name=libpcap.a)
 
 targets := pcap_kern.o pcap_user.o
 

arch/um/sys-i386/Makefile

@@ -20,4 +20,4 @@ CFLAGS_stub_segv.o := $(CFLAGS_NO_HARDENING)
 
 include arch/um/scripts/Makefile.rules
 
-$(obj)/unmap.%: _c_flags = $(call unprofile,$(CFLAGS))
+$(obj)/unmap.%: _c_flags = $(call unprofile,$(KBUILD_CFLAGS))

arch/um/sys-x86_64/Makefile

@@ -28,4 +28,4 @@ CFLAGS_stub_segv.o := $(CFLAGS_NO_HARDENING)
 
 include arch/um/scripts/Makefile.rules
 
-$(obj)/unmap.%: _c_flags = $(call unprofile,$(CFLAGS))
+$(obj)/unmap.%: _c_flags = $(call unprofile,$(KBUILD_CFLAGS))

arch/v850/Makefile

@@ -16,11 +16,11 @@
 
 arch_dir = arch/v850
 
-CFLAGS += -mv850e
+KBUILD_CFLAGS += -mv850e
 # r16 is a fixed pointer to the current task
-CFLAGS += -ffixed-r16 -mno-prolog-function
-CFLAGS += -fno-builtin
-CFLAGS += -D__linux__ -DUTS_SYSNAME=\"uClinux\"
+KBUILD_CFLAGS += -ffixed-r16 -mno-prolog-function
+KBUILD_CFLAGS += -fno-builtin
+KBUILD_CFLAGS += -D__linux__ -DUTS_SYSNAME=\"uClinux\"
 
 # By default, build a kernel that runs on the gdb v850 simulator.
 KBUILD_DEFCONFIG := sim_defconfig

arch/x86/boot/Makefile

@@ -50,7 +50,7 @@ HOSTCFLAGS_build.o := $(LINUXINCLUDE)
 # that way we can complain to the user if the CPU is insufficient.
 cflags-i386   := 
 cflags-x86_64 := -m32
-CFLAGS		:= $(LINUXINCLUDE) -g -Os -D_SETUP -D__KERNEL__ \
+KBUILD_CFLAGS	:= $(LINUXINCLUDE) -g -Os -D_SETUP -D__KERNEL__ \
 		   $(cflags-$(ARCH)) \
 		   -Wall -Wstrict-prototypes \
 		   -march=i386 -mregparm=3 \
@@ -61,7 +61,7 @@ CFLAGS		:= $(LINUXINCLUDE) -g -Os -D_SETUP -D__KERNEL__ \
 			$(call cc-option, -fno-unit-at-a-time)) \
 		   $(call cc-option, -fno-stack-protector) \
 		   $(call cc-option, -mpreferred-stack-boundary=2)
-AFLAGS		:= $(CFLAGS) -D__ASSEMBLY__
+AFLAGS		:= $(KBUILD_CFLAGS) -D__ASSEMBLY__
 
 $(obj)/zImage:  IMAGE_OFFSET := 0x1000
 $(obj)/zImage:  EXTRA_AFLAGS := $(SVGA_MODE) $(RAMDISK)

arch/x86/boot/compressed/Makefile_32

@@ -11,7 +11,7 @@ EXTRA_AFLAGS	:= -traditional
 LDFLAGS_vmlinux := -T
 hostprogs-y	:= relocs
 
-CFLAGS  := -m32 -D__KERNEL__ $(LINUX_INCLUDE) -O2 \
+KBUILD_CFLAGS  := -m32 -D__KERNEL__ $(LINUX_INCLUDE) -O2 \
 	   -fno-strict-aliasing -fPIC \
 	   $(call cc-option,-ffreestanding) \
 	   $(call cc-option,-fno-stack-protector)

arch/x86/boot/compressed/Makefile_64

@@ -6,11 +6,11 @@
 
 targets		:= vmlinux vmlinux.bin vmlinux.bin.gz head_64.o misc_64.o piggy.o
 
-CFLAGS := -m64 -D__KERNEL__ $(LINUXINCLUDE) -O2  \
+KBUILD_CFLAGS := -m64 -D__KERNEL__ $(LINUXINCLUDE) -O2  \
 	  -fno-strict-aliasing -fPIC -mcmodel=small \
 	   $(call cc-option, -ffreestanding) \
 	   $(call cc-option, -fno-stack-protector)
-AFLAGS  := $(CFLAGS) -D__ASSEMBLY__
+AFLAGS  := $(KBUILD_CFLAGS) -D__ASSEMBLY__
 LDFLAGS := -m elf_x86_64
 
 LDFLAGS_vmlinux := -T

arch/x86/vdso/Makefile

@@ -34,8 +34,8 @@ $(obj)/vdso.so: $(src)/vdso.lds $(vobjs) FORCE
 
 CFL := $(PROFILING) -mcmodel=small -fPIC -g0 -O2 -fasynchronous-unwind-tables -m64
 
-$(obj)/vclock_gettime.o: CFLAGS = $(CFL)
-$(obj)/vgetcpu.o: CFLAGS = $(CFL)
+$(obj)/vclock_gettime.o: KBUILD_CFLAGS = $(CFL)
+$(obj)/vgetcpu.o: KBUILD_CFLAGS = $(CFL)
 
 # We also create a special relocatable object that should mirror the symbol
 # table and layout of the linked DSO.  With ld -R we can then refer to

arch/x86_64/Makefile

@@ -70,7 +70,7 @@ AFLAGS += $(call as-instr,.cfi_startproc\n.cfi_signal_frame\n.cfi_endproc,-DCONF
 cflags-$(CONFIG_CC_STACKPROTECTOR) += $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-x86_64-has-stack-protector.sh "$(CC)" -fstack-protector )
 cflags-$(CONFIG_CC_STACKPROTECTOR_ALL) += $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-x86_64-has-stack-protector.sh "$(CC)" -fstack-protector-all )
 
-CFLAGS += $(cflags-y)
+KBUILD_CFLAGS += $(cflags-y)
 CFLAGS_KERNEL += $(cflags-kernel-y)
 AFLAGS += -m64
 

arch/xtensa/Makefile

@@ -28,11 +28,9 @@ PLATFORM = $(platform-y)
 export PLATFORM
 
 # temporarily until string.h is fixed
-cflags-y += -ffreestanding
+KBUILD_CFLAGS += -ffreestanding
 
-cflags-y += -pipe -mlongcalls
-
-CFLAGS  += $(cflags-y)
+KBUILD_CFLAGS += -pipe -mlongcalls
 
 KBUILD_DEFCONFIG := iss_defconfig
 
@@ -56,7 +54,7 @@ endif
 
 #
 
-LIBGCC := $(shell $(CC) $(CFLAGS) -print-libgcc-file-name)
+LIBGCC := $(shell $(CC) $(KBUILD_CFLAGS) -print-libgcc-file-name)
 
 head-y		:= arch/xtensa/kernel/head.o
 core-y		+= arch/xtensa/kernel/ arch/xtensa/mm/

arch/xtensa/boot/boot-redboot/Makefile

@@ -19,7 +19,7 @@ boot-y	:= bootstrap.o
 OBJS	:= $(addprefix $(obj)/,$(boot-y))
 LIBS	:= arch/xtensa/boot/lib/lib.a arch/xtensa/lib/lib.a
 
-LIBGCC := $(shell $(CC) $(CFLAGS) -print-libgcc-file-name)
+LIBGCC := $(shell $(CC) $(KBUILD_CFLAGS) -print-libgcc-file-name)
 
 zImage: vmlinux $(OBJS) $(LIBS)
 	$(OBJCOPY) --strip-all -R .comment -R .xt.insn -O binary \

init/Makefile

@@ -30,4 +30,4 @@ $(obj)/version.o: include/linux/compile.h
 include/linux/compile.h: FORCE
 	@echo '  CHK     $@'
 	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkcompile_h $@ \
-	"$(UTS_MACHINE)" "$(CONFIG_SMP)" "$(CONFIG_PREEMPT)" "$(CC) $(CFLAGS)"
+	"$(UTS_MACHINE)" "$(CONFIG_SMP)" "$(CONFIG_PREEMPT)" "$(CC) $(KBUILD_CFLAGS)"

scripts/Kbuild.include

@@ -75,7 +75,7 @@ try-run = $(shell set -e;		\
 # Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
 
 as-option = $(call try-run,\
-	$(CC) $(CFLAGS) $(1) -c -xassembler /dev/null -o "$$TMP",$(1),$(2))
+	$(CC) $(KBUILD_CFLAGS) $(1) -c -xassembler /dev/null -o "$$TMP",$(1),$(2))
 
 # as-instr
 # Usage: cflags-y += $(call as-instr,instr,option1,option2)
@@ -87,12 +87,12 @@ as-instr = $(call try-run,\
 # Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
 
 cc-option = $(call try-run,\
-	$(CC) $(CFLAGS) $(1) -S -xc /dev/null -o "$$TMP",$(1),$(2))
+	$(CC) $(KBUILD_CFLAGS) $(1) -S -xc /dev/null -o "$$TMP",$(1),$(2))
 
 # cc-option-yn
 # Usage: flag := $(call cc-option-yn,-march=winchip-c6)
 cc-option-yn = $(call try-run,\
-	$(CC) $(CFLAGS) $(1) -S -xc /dev/null -o "$$TMP",y,n)
+	$(CC) $(KBUILD_CFLAGS) $(1) -S -xc /dev/null -o "$$TMP",y,n)
 
 # cc-option-align
 # Prefix align with either -falign or -malign

scripts/Makefile.lib

@@ -84,7 +84,7 @@ basename_flags = -D"KBUILD_BASENAME=KBUILD_STR($(call name-fix,$(basetarget)))"
 modname_flags  = $(if $(filter 1,$(words $(modname))),\
                  -D"KBUILD_MODNAME=KBUILD_STR($(call name-fix,$(modname)))")
 
-_c_flags       = $(CFLAGS) $(EXTRA_CFLAGS) $(CFLAGS_$(basetarget).o)
+_c_flags       = $(KBUILD_CFLAGS) $(EXTRA_CFLAGS) $(CFLAGS_$(basetarget).o)
 _a_flags       = $(AFLAGS) $(EXTRA_AFLAGS) $(AFLAGS_$(basetarget).o)
 _cpp_flags     = $(CPPFLAGS) $(EXTRA_CPPFLAGS) $(CPPFLAGS_$(@F))