171 lines
6.7 KiB
Makefile
171 lines
6.7 KiB
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.
|
||
|
|
#
|
||
|
|
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) := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \
|
||
|
|
-fpie $(DISABLE_STACKLEAK_PLUGIN) \
|
||
|
|
$(call cc-option,-mbranch-protection=none)
|
||
|
|
cflags-$(CONFIG_ARM) := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \
|
||
|
|
-fno-builtin -fpic \
|
||
|
|
$(call cc-option,-mno-single-pic-base)
|
||
|
|
cflags-$(CONFIG_RISCV) := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \
|
||
|
|
-fpic
|
||
|
|
cflags-$(CONFIG_LOONGARCH) := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \
|
||
|
|
-fpie
|
||
|
|
|
||
|
|
cflags-$(CONFIG_EFI_PARAMS_FROM_FDT) += -I$(srctree)/scripts/dtc/libfdt
|
||
|
|
|
||
|
|
KBUILD_CFLAGS := $(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), $(KBUILD_CFLAGS))
|
||
|
|
|
||
|
|
GCOV_PROFILE := n
|
||
|
|
# Sanitizer runtimes are unavailable and cannot be linked here.
|
||
|
|
KASAN_SANITIZE := n
|
||
|
|
KCSAN_SANITIZE := n
|
||
|
|
KMSAN_SANITIZE := n
|
||
|
|
UBSAN_SANITIZE := n
|
||
|
|
OBJECT_FILES_NON_STANDARD := y
|
||
|
|
|
||
|
|
# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
|
||
|
|
KCOV_INSTRUMENT := n
|
||
|
|
|
||
|
|
lib-y := efi-stub-helper.o gop.o secureboot.o tpm.o \
|
||
|
|
file.o mem.o random.o randomalloc.o pci.o \
|
||
|
|
skip_spaces.o lib-cmdline.o lib-ctype.o \
|
||
|
|
alignedmem.o relocate.o vsprintf.o
|
||
|
|
|
||
|
|
# include the stub's libfdt dependencies from lib/ when needed
|
||
|
|
libfdt-deps := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c \
|
||
|
|
fdt_empty_tree.c fdt_sw.c
|
||
|
|
|
||
|
|
lib-$(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
|
||
|
|
|
||
|
|
lib-$(CONFIG_ARM) += arm32-stub.o
|
||
|
|
lib-$(CONFIG_ARM64) += arm64-stub.o smbios.o
|
||
|
|
lib-$(CONFIG_X86) += x86-stub.o
|
||
|
|
lib-$(CONFIG_RISCV) += riscv-stub.o
|
||
|
|
lib-$(CONFIG_LOONGARCH) += loongarch-stub.o
|
||
|
|
|
||
|
|
CFLAGS_arm32-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET)
|
||
|
|
|
||
|
|
zboot-obj-$(CONFIG_RISCV) := lib-clz_ctz.o lib-ashldi3.o
|
||
|
|
lib-$(CONFIG_EFI_ZBOOT) += zboot.o $(zboot-obj-y)
|
||
|
|
|
||
|
|
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://bugs.llvm.org/show_bug.cgi?id=46480
|
||
|
|
STUBCOPY_FLAGS-y += --remove-section=.note.gnu.property
|
||
|
|
|
||
|
|
#
|
||
|
|
# For x86, bootloaders like systemd-boot or grub-efi do not zero-initialize the
|
||
|
|
# .bss section, so the .bss section of the EFI stub needs to be included in the
|
||
|
|
# .data section of the compressed kernel to ensure initialization. Rename the
|
||
|
|
# .bss section here so it's easy to pick out in the linker script.
|
||
|
|
#
|
||
|
|
STUBCOPY_FLAGS-$(CONFIG_X86) += --rename-section .bss=.bss.efistub,load,alloc
|
||
|
|
STUBCOPY_RELOC-$(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-$(CONFIG_ARM64) := R_AARCH64_ABS
|
||
|
|
|
||
|
|
# For RISC-V, we don't need anything special other than arm64. Keep all the
|
||
|
|
# symbols in .init section and make sure that no absolute symbols references
|
||
|
|
# doesn't exist.
|
||
|
|
STUBCOPY_FLAGS-$(CONFIG_RISCV) += --prefix-alloc-sections=.init \
|
||
|
|
--prefix-symbols=__efistub_
|
||
|
|
STUBCOPY_RELOC-$(CONFIG_RISCV) := R_RISCV_HI20
|
||
|
|
|
||
|
|
# For LoongArch, keep all the symbols in .init section and make sure that no
|
||
|
|
# absolute symbols references exist.
|
||
|
|
STUBCOPY_FLAGS-$(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) $< $@
|