mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/herbert/cryptodev-2.6.git
synced 2026-04-27 03:49:57 -04:00
b92165d2ba
The UEFI spec defines (and deprecates) a misguided and shortlived memory protection feature that is based on splitting memory regions covering PE/COFF executables into separate code and data regions, without annotating them as belonging to the same executable image. When the OS assigns the virtual addresses of these regions, it may move them around arbitrarily, without taking into account that the PE/COFF code sections may contain relative references into the data sections, which means the relative placement of these segments has to be preserved or the executable image will be corrupted. The original workaround on arm64 was to ensure that adjacent regions of the same type were mapped adjacently in the virtual mapping, but this requires sorting of the memory map, which we would prefer to avoid. Considering that the native physical mapping of the PE/COFF images does not suffer from this issue, let's preserve it at runtime, and install it as the virtual mapping as well. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
104 lines
4.0 KiB
Makefile
104 lines
4.0 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__ -O2 \
|
|
-fPIC -fno-strict-aliasing -mno-red-zone \
|
|
-mno-mmx -mno-sse -fshort-wchar \
|
|
-Wno-pointer-sign \
|
|
$(call cc-disable-warning, address-of-packed-member) \
|
|
$(call cc-disable-warning, gnu)
|
|
|
|
# arm64 uses the full KBUILD_CFLAGS so it's necessary to explicitly
|
|
# disable the stackleak plugin
|
|
cflags-$(CONFIG_ARM64) := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \
|
|
-fpie $(DISABLE_STACKLEAK_PLUGIN)
|
|
cflags-$(CONFIG_ARM) := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \
|
|
-fno-builtin -fpic \
|
|
$(call cc-option,-mno-single-pic-base)
|
|
|
|
cflags-$(CONFIG_EFI_ARMSTUB) += -I$(srctree)/scripts/dtc/libfdt
|
|
|
|
KBUILD_CFLAGS := $(cflags-y) -DDISABLE_BRANCH_PROFILING \
|
|
-D__NO_FORTIFY \
|
|
$(call cc-option,-ffreestanding) \
|
|
$(call cc-option,-fno-stack-protector) \
|
|
-D__DISABLE_EXPORTS
|
|
|
|
GCOV_PROFILE := n
|
|
KASAN_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 \
|
|
random.o pci.o
|
|
|
|
# include the stub's generic dependencies from lib/ when building for ARM/arm64
|
|
arm-deps-y := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c fdt_empty_tree.c fdt_sw.c
|
|
|
|
$(obj)/lib-%.o: $(srctree)/lib/%.c FORCE
|
|
$(call if_changed_rule,cc_o_c)
|
|
|
|
lib-$(CONFIG_EFI_ARMSTUB) += arm-stub.o fdt.o string.o \
|
|
$(patsubst %.c,lib-%.o,$(arm-deps-y))
|
|
|
|
lib-$(CONFIG_ARM) += arm32-stub.o
|
|
lib-$(CONFIG_ARM64) += arm64-stub.o
|
|
CFLAGS_arm32-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET)
|
|
CFLAGS_arm64-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET)
|
|
|
|
#
|
|
# 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.
|
|
#
|
|
extra-$(CONFIG_EFI_ARMSTUB) := $(lib-y)
|
|
lib-$(CONFIG_EFI_ARMSTUB) := $(patsubst %.o,%.stub.o,$(lib-y))
|
|
|
|
STUBCOPY_FLAGS-$(CONFIG_ARM64) += --prefix-alloc-sections=.init \
|
|
--prefix-symbols=__efistub_
|
|
STUBCOPY_RELOC-$(CONFIG_ARM64) := R_AARCH64_ABS
|
|
|
|
$(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) $< $@
|
|
|
|
#
|
|
# ARM discards the .data section because it disallows r/w data in the
|
|
# decompressor. So move our .data to .data.efistub, which is preserved
|
|
# explicitly by the decompressor linker script.
|
|
#
|
|
STUBCOPY_FLAGS-$(CONFIG_ARM) += --rename-section .data=.data.efistub
|
|
STUBCOPY_RELOC-$(CONFIG_ARM) := R_ARM_ABS
|