[linux-2.6-block.git] / drivers / firmware / efi / libstub / Makefile

# SPDX-License-Identifier: GPL-2.0
#
# The stub may be linked into the kernel proper or into a separate boot binary,
# but in either case, it executes before the kernel does (with MMU disabled) so
# things like ftrace and stack-protector are likely to cause trouble if left
# enabled, even if doing so doesn't break the build.
#

# non-x86 reuses KBUILD_CFLAGS, x86 does not
cflags-y			:= $(KBUILD_CFLAGS)

cflags-$(CONFIG_X86_32)		:= -march=i386
cflags-$(CONFIG_X86_64)		:= -mcmodel=small
cflags-$(CONFIG_X86)		+= -m$(BITS) -D__KERNEL__ \
				   -fPIC -fno-strict-aliasing -mno-red-zone \
				   -mno-mmx -mno-sse -fshort-wchar \
				   -Wno-pointer-sign \
				   $(call cc-disable-warning, address-of-packed-member) \
				   $(call cc-disable-warning, gnu) \
				   -fno-asynchronous-unwind-tables \
				   $(CLANG_FLAGS)

# arm64 uses the full KBUILD_CFLAGS so it's necessary to explicitly
# disable the stackleak plugin
cflags-$(CONFIG_ARM64)		+= -fpie $(DISABLE_STACKLEAK_PLUGIN) \
				   -fno-unwind-tables -fno-asynchronous-unwind-tables
cflags-$(CONFIG_ARM)		+= -DEFI_HAVE_STRLEN -DEFI_HAVE_STRNLEN \
				   -DEFI_HAVE_MEMCHR -DEFI_HAVE_STRRCHR \
				   -DEFI_HAVE_STRCMP -fno-builtin -fpic \
				   $(call cc-option,-mno-single-pic-base)
cflags-$(CONFIG_RISCV)		+= -fpic -DNO_ALTERNATIVE -mno-relax
cflags-$(CONFIG_LOONGARCH)	+= -fpie

cflags-$(CONFIG_EFI_PARAMS_FROM_FDT)	+= -I$(srctree)/scripts/dtc/libfdt

KBUILD_CFLAGS			:= $(subst $(CC_FLAGS_FTRACE),,$(cflags-y)) \
				   -Os -DDISABLE_BRANCH_PROFILING \
				   -include $(srctree)/include/linux/hidden.h \
				   -D__NO_FORTIFY \
				   -ffreestanding \
				   -fno-stack-protector \
				   $(call cc-option,-fno-addrsig) \
				   -D__DISABLE_EXPORTS

#
# struct randomization only makes sense for Linux internal types, which the EFI
# stub code never touches, so let's turn off struct randomization for the stub
# altogether
#
KBUILD_CFLAGS := $(filter-out $(RANDSTRUCT_CFLAGS), $(KBUILD_CFLAGS))

# remove SCS flags from all objects in this directory
KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_SCS), $(KBUILD_CFLAGS))
# disable CFI
KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_CFI), $(KBUILD_CFLAGS))
# disable LTO
KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_LTO), $(KBUILD_CFLAGS))

lib-y				:= efi-stub-helper.o gop.o secureboot.o tpm.o \
				   file.o mem.o random.o randomalloc.o pci.o \
				   skip_spaces.o lib-cmdline.o lib-ctype.o \
				   alignedmem.o relocate.o printk.o vsprintf.o

# include the stub's libfdt dependencies from lib/ when needed
libfdt-deps			:= fdt_rw.c fdt_ro.c fdt_wip.c fdt.c \
				   fdt_empty_tree.c fdt_sw.c

lib-$(CONFIG_EFI_PARAMS_FROM_FDT) += fdt.o \
				     $(patsubst %.c,lib-%.o,$(libfdt-deps))

$(obj)/lib-%.o: $(srctree)/lib/%.c FORCE
	$(call if_changed_rule,cc_o_c)

lib-$(CONFIG_EFI_GENERIC_STUB)	+= efi-stub.o string.o intrinsics.o systable.o \
				   screen_info.o efi-stub-entry.o

lib-$(CONFIG_ARM)		+= arm32-stub.o
lib-$(CONFIG_ARM64)		+= kaslr.o arm64.o arm64-stub.o smbios.o
lib-$(CONFIG_X86)		+= x86-stub.o
lib-$(CONFIG_X86_64)		+= x86-5lvl.o
lib-$(CONFIG_RISCV)		+= kaslr.o riscv.o riscv-stub.o
lib-$(CONFIG_LOONGARCH)		+= loongarch.o loongarch-stub.o

CFLAGS_arm32-stub.o		:= -DTEXT_OFFSET=$(TEXT_OFFSET)

zboot-obj-$(CONFIG_RISCV)	:= lib-clz_ctz.o lib-ashldi3.o
lib-$(CONFIG_EFI_ZBOOT)		+= zboot.o $(zboot-obj-y)

lib-$(CONFIG_UNACCEPTED_MEMORY) += unaccepted_memory.o bitmap.o find.o

extra-y				:= $(lib-y)
lib-y				:= $(patsubst %.o,%.stub.o,$(lib-y))

# Even when -mbranch-protection=none is set, Clang will generate a
# .note.gnu.property for code-less object files (like lib/ctype.c),
# so work around this by explicitly removing the unwanted section.
# https://llvm.org/pr46480
STUBCOPY_FLAGS-y		+= --remove-section=.note.gnu.property

STUBCOPY_RELOC-$(CONFIG_X86_32)	:= R_386_32
STUBCOPY_RELOC-$(CONFIG_X86_64)	:= R_X86_64_64

#
# ARM discards the .data section because it disallows r/w data in the
# decompressor. So move our .data to .data.efistub and .bss to .bss.efistub,
# which are preserved explicitly by the decompressor linker script.
#
STUBCOPY_FLAGS-$(CONFIG_ARM)	+= --rename-section .data=.data.efistub	\
				   --rename-section .bss=.bss.efistub,load,alloc
STUBCOPY_RELOC-$(CONFIG_ARM)	:= R_ARM_ABS

#
# arm64 puts the stub in the kernel proper, which will unnecessarily retain all
# code indefinitely unless it is annotated as __init/__initdata/__initconst etc.
# So let's apply the __init annotations at the section level, by prefixing
# the section names directly. This will ensure that even all the inline string
# literals are covered.
# The fact that the stub and the kernel proper are essentially the same binary
# also means that we need to be extra careful to make sure that the stub does
# not rely on any absolute symbol references, considering that the virtual
# kernel mapping that the linker uses is not active yet when the stub is
# executing. So build all C dependencies of the EFI stub into libstub, and do
# a verification pass to see if any absolute relocations exist in any of the
# object files.
#
STUBCOPY_FLAGS-$(CONFIG_ARM64)	+= --prefix-alloc-sections=.init \
				   --prefix-symbols=__efistub_
STUBCOPY_RELOC-$(CONFIG_ARM64)	:= R_AARCH64_ABS

# For RISC-V, we don't need anything special other than arm64. Keep all the
# symbols in .init section and make sure that no absolute symbols references
# exist.
STUBCOPY_FLAGS-$(CONFIG_RISCV)	+= --prefix-alloc-sections=.init \
				   --prefix-symbols=__efistub_
STUBCOPY_RELOC-$(CONFIG_RISCV)	:= -E R_RISCV_HI20\|R_RISCV_$(BITS)\|R_RISCV_RELAX

# For LoongArch, keep all the symbols in .init section and make sure that no
# absolute symbols references exist.
STUBCOPY_FLAGS-$(CONFIG_LOONGARCH)	+= --prefix-alloc-sections=.init \
					   --prefix-symbols=__efistub_
STUBCOPY_RELOC-$(CONFIG_LOONGARCH)	:= R_LARCH_MARK_LA

$(obj)/%.stub.o: $(obj)/%.o FORCE
	$(call if_changed,stubcopy)

#
# Strip debug sections and some other sections that may legally contain
# absolute relocations, so that we can inspect the remaining sections for
# such relocations. If none are found, regenerate the output object, but
# this time, use objcopy and leave all sections in place.
#
quiet_cmd_stubcopy = STUBCPY $@
      cmd_stubcopy =							\
	$(STRIP) --strip-debug -o $@ $<;				\
	if $(OBJDUMP) -r $@ | grep $(STUBCOPY_RELOC-y); then		\
		echo "$@: absolute symbol references not allowed in the EFI stub" >&2; \
		/bin/false;						\
	fi;								\
	$(OBJCOPY) $(STUBCOPY_FLAGS-y) $< $@
Commit	Line	Data
b2441318	1	# SPDX-License-Identifier: GPL-2.0
f4f75ad5 AB	2	#
	3	# The stub may be linked into the kernel proper or into a separate boot binary,
	4	# but in either case, it executes before the kernel does (with MMU disabled) so
	5	# things like ftrace and stack-protector are likely to cause trouble if left
	6	# enabled, even if doing so doesn't break the build.
	7	#
0d60ffee AB	8
	9	# non-x86 reuses KBUILD_CFLAGS, x86 does not
	10	cflags-y := $(KBUILD_CFLAGS)
	11
f4f75ad5	12	cflags-$(CONFIG_X86_32) := -march=i386
769e0fe1	13	cflags-$(CONFIG_X86_64) := -mcmodel=small
bbf8e8b0	14	cflags-$(CONFIG_X86) += -m$(BITS) -D__KERNEL__ \
f4f75ad5	15	-fPIC -fno-strict-aliasing -mno-red-zone \
3db5e0ba NC	16	-mno-mmx -mno-sse -fshort-wchar \
	17	-Wno-pointer-sign \
	18	$(call cc-disable-warning, address-of-packed-member) \
003602ad	19	$(call cc-disable-warning, gnu) \
58d746c1 NC	20	-fno-asynchronous-unwind-tables \
58d746c1 NC	21	$(CLANG_FLAGS)
f4f75ad5	22
ce279d37 LA	23	# arm64 uses the full KBUILD_CFLAGS so it's necessary to explicitly
ce279d37 LA	24	# disable the stackleak plugin
0d60ffee	25	cflags-$(CONFIG_ARM64) += -fpie $(DISABLE_STACKLEAK_PLUGIN) \
8358098b	26	-fno-unwind-tables -fno-asynchronous-unwind-tables
2e6fa86f	27	cflags-$(CONFIG_ARM) += -DEFI_HAVE_STRLEN -DEFI_HAVE_STRNLEN \
da8dd0c7 AB	28	-DEFI_HAVE_MEMCHR -DEFI_HAVE_STRRCHR \
da8dd0c7 AB	29	-DEFI_HAVE_STRCMP -fno-builtin -fpic \
41f1c484	30	$(call cc-option,-mno-single-pic-base)
afb2a4fb	31	cflags-$(CONFIG_RISCV) += -fpic -DNO_ALTERNATIVE -mno-relax
0d60ffee	32	cflags-$(CONFIG_LOONGARCH) += -fpie
f4f75ad5	33
40cd01a9	34	cflags-$(CONFIG_EFI_PARAMS_FROM_FDT) += -I$(srctree)/scripts/dtc/libfdt
e8f3010f	35
0d60ffee AB	36	KBUILD_CFLAGS := $(subst $(CC_FLAGS_FTRACE),,$(cflags-y)) \
0d60ffee AB	37	-Os -DDISABLE_BRANCH_PROFILING \
e544ea57	38	-include $(srctree)/include/linux/hidden.h \
3e2c044a	39	-D__NO_FORTIFY \
685969e0	40	-ffreestanding \
893ab004	41	-fno-stack-protector \
f77767ed	42	$(call cc-option,-fno-addrsig) \
f922c4ab	43	-D__DISABLE_EXPORTS
f4f75ad5	44
1a388792 AB	45	#
	46	# struct randomization only makes sense for Linux internal types, which the EFI
	47	# stub code never touches, so let's turn off struct randomization for the stub
	48	# altogether
	49	#
	50	KBUILD_CFLAGS := $(filter-out $(RANDSTRUCT_CFLAGS), $(KBUILD_CFLAGS))
	51
cc49c71d ST	52	# remove SCS flags from all objects in this directory
cc49c71d ST	53	KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_SCS), $(KBUILD_CFLAGS))
f143ff39 ST	54	# disable CFI
f143ff39 ST	55	KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_CFI), $(KBUILD_CFLAGS))
6e20f185 ST	56	# disable LTO
6e20f185 ST	57	KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_LTO), $(KBUILD_CFLAGS))
cc49c71d	58
0d959814	59	lib-y := efi-stub-helper.o gop.o secureboot.o tpm.o \
91d150c0	60	file.o mem.o random.o randomalloc.o pci.o \
43b1df0e	61	skip_spaces.o lib-cmdline.o lib-ctype.o \
2e6fa86f	62	alignedmem.o relocate.o printk.o vsprintf.o
e8f3010f	63
40cd01a9 AB	64	# include the stub's libfdt dependencies from lib/ when needed
	65	libfdt-deps := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c \
	66	fdt_empty_tree.c fdt_sw.c
	67
	68	lib-$(CONFIG_EFI_PARAMS_FROM_FDT) += fdt.o \
	69	$(patsubst %.c,lib-%.o,$(libfdt-deps))
e8f3010f AB	70
	71	$(obj)/lib-%.o: $(srctree)/lib/%.c FORCE
	72	$(call if_changed_rule,cc_o_c)
	73
732ea9db	74	lib-$(CONFIG_EFI_GENERIC_STUB) += efi-stub.o string.o intrinsics.o systable.o \
42c8ea3d	75	screen_info.o efi-stub-entry.o
f4f75ad5	76
81a0bc39	77	lib-$(CONFIG_ARM) += arm32-stub.o
6b56beb5	78	lib-$(CONFIG_ARM64) += kaslr.o arm64.o arm64-stub.o smbios.o
c2d0b470	79	lib-$(CONFIG_X86) += x86-stub.o
cb1c9e02	80	lib-$(CONFIG_X86_64) += x86-5lvl.o
b7ac4b8e	81	lib-$(CONFIG_RISCV) += kaslr.o riscv.o riscv-stub.o
d729b554	82	lib-$(CONFIG_LOONGARCH) += loongarch.o loongarch-stub.o
ead384d9	83
41cd96fa	84	CFLAGS_arm32-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET)
bf457786	85
a0509109 AB	86	zboot-obj-$(CONFIG_RISCV) := lib-clz_ctz.o lib-ashldi3.o
	87	lib-$(CONFIG_EFI_ZBOOT) += zboot.o $(zboot-obj-y)
	88
745e3ed8 KS	89	lib-$(CONFIG_UNACCEPTED_MEMORY) += unaccepted_memory.o bitmap.o find.o
745e3ed8 KS	90
a0509109 AB	91	extra-y := $(lib-y)
	92	lib-y := $(patsubst %.o,%.stub.o,$(lib-y))
	93
e2179a09 KC	94	# Even when -mbranch-protection=none is set, Clang will generate a
	95	# .note.gnu.property for code-less object files (like lib/ctype.c),
	96	# so work around this by explicitly removing the unwanted section.
2947a456	97	# https://llvm.org/pr46480
e2179a09 KC	98	STUBCOPY_FLAGS-y += --remove-section=.note.gnu.property
e2179a09 KC	99
26a92425 AS	100	STUBCOPY_RELOC-$(CONFIG_X86_32) := R_386_32
	101	STUBCOPY_RELOC-$(CONFIG_X86_64) := R_X86_64_64
	102
	103	#
	104	# ARM discards the .data section because it disallows r/w data in the
	105	# decompressor. So move our .data to .data.efistub and .bss to .bss.efistub,
	106	# which are preserved explicitly by the decompressor linker script.
	107	#
	108	STUBCOPY_FLAGS-$(CONFIG_ARM) += --rename-section .data=.data.efistub \
	109	--rename-section .bss=.bss.efistub,load,alloc
	110	STUBCOPY_RELOC-$(CONFIG_ARM) := R_ARM_ABS
	111
ddeeefe2 AB	112	#
	113	# arm64 puts the stub in the kernel proper, which will unnecessarily retain all
	114	# code indefinitely unless it is annotated as __init/__initdata/__initconst etc.
	115	# So let's apply the __init annotations at the section level, by prefixing
	116	# the section names directly. This will ensure that even all the inline string
	117	# literals are covered.
e8f3010f AB	118	# The fact that the stub and the kernel proper are essentially the same binary
	119	# also means that we need to be extra careful to make sure that the stub does
	120	# not rely on any absolute symbol references, considering that the virtual
	121	# kernel mapping that the linker uses is not active yet when the stub is
	122	# executing. So build all C dependencies of the EFI stub into libstub, and do
	123	# a verification pass to see if any absolute relocations exist in any of the
	124	# object files.
ddeeefe2	125	#
e8f3010f AB	126	STUBCOPY_FLAGS-$(CONFIG_ARM64) += --prefix-alloc-sections=.init \
e8f3010f AB	127	--prefix-symbols=__efistub_
61786170	128	STUBCOPY_RELOC-$(CONFIG_ARM64) := R_AARCH64_ABS
e8f3010f	129
d7071743 AP	130	# For RISC-V, we don't need anything special other than arm64. Keep all the
d7071743 AP	131	# symbols in .init section and make sure that no absolute symbols references
f6e6e95c	132	# exist.
d7071743 AP	133	STUBCOPY_FLAGS-$(CONFIG_RISCV) += --prefix-alloc-sections=.init \
d7071743 AP	134	--prefix-symbols=__efistub_
d2baf8cc	135	STUBCOPY_RELOC-$(CONFIG_RISCV) := -E R_RISCV_HI20\\|R_RISCV_$(BITS)\\|R_RISCV_RELAX
d7071743	136
ead384d9 HC	137	# For LoongArch, keep all the symbols in .init section and make sure that no
	138	# absolute symbols references exist.
	139	STUBCOPY_FLAGS-$(CONFIG_LOONGARCH) += --prefix-alloc-sections=.init \
	140	--prefix-symbols=__efistub_
	141	STUBCOPY_RELOC-$(CONFIG_LOONGARCH) := R_LARCH_MARK_LA
	142
e8f3010f AB	143	$(obj)/%.stub.o: $(obj)/%.o FORCE
e8f3010f AB	144	$(call if_changed,stubcopy)
ddeeefe2	145
696204fa AB	146	#
	147	# Strip debug sections and some other sections that may legally contain
	148	# absolute relocations, so that we can inspect the remaining sections for
	149	# such relocations. If none are found, regenerate the output object, but
	150	# this time, use objcopy and leave all sections in place.
	151	#
e8f3010f	152	quiet_cmd_stubcopy = STUBCPY $@
e8d368ad	153	cmd_stubcopy = \
02562d0c	154	$(STRIP) --strip-debug -o $@ $<; \
e8d368ad MY	155	if $(OBJDUMP) -r $@ \| grep $(STUBCOPY_RELOC-y); then \
	156	echo "$@: absolute symbol references not allowed in the EFI stub" >&2; \
	157	/bin/false; \
	158	fi; \
	159	$(OBJCOPY) $(STUBCOPY_FLAGS-y) $< $@