mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-09 18:19:06 +00:00
74afda4016
Compile all functions with two ptrauth instructions: PACIASP in the prologue to sign the return address, and AUTIASP in the epilogue to authenticate the return address (from the stack). If authentication fails, the return will cause an instruction abort to be taken, followed by an oops and killing the task. This should help protect the kernel against attacks using return-oriented programming. As ptrauth protects the return address, it can also serve as a replacement for CONFIG_STACKPROTECTOR, although note that it does not protect other parts of the stack. The new instructions are in the HINT encoding space, so on a system without ptrauth they execute as NOPs. CONFIG_ARM64_PTR_AUTH now not only enables ptrauth for userspace and KVM guests, but also automatically builds the kernel with ptrauth instructions if the compiler supports it. If there is no compiler support, we do not warn that the kernel was built without ptrauth instructions. GCC 7 and 8 support the -msign-return-address option, while GCC 9 deprecates that option and replaces it with -mbranch-protection. Support both options. Clang uses an external assembler hence this patch makes sure that the correct parameters (-march=armv8.3-a) are passed down to help it recognize the ptrauth instructions. Ftrace function tracer works properly with Ptrauth only when patchable-function-entry feature is present and is ensured by the Kconfig dependency. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com> # not co-dev parts Co-developed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> [Amit: Cover leaf function, comments, Ftrace Kconfig] Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
182 lines
6 KiB
Makefile
182 lines
6 KiB
Makefile
#
|
|
# arch/arm64/Makefile
|
|
#
|
|
# This file is included by the global makefile so that you can add your own
|
|
# architecture-specific flags and dependencies.
|
|
#
|
|
# This file is subject to the terms and conditions of the GNU General Public
|
|
# License. See the file "COPYING" in the main directory of this archive
|
|
# for more details.
|
|
#
|
|
# Copyright (C) 1995-2001 by Russell King
|
|
|
|
LDFLAGS_vmlinux :=--no-undefined -X
|
|
CPPFLAGS_vmlinux.lds = -DTEXT_OFFSET=$(TEXT_OFFSET)
|
|
GZFLAGS :=-9
|
|
|
|
ifeq ($(CONFIG_RELOCATABLE), y)
|
|
# Pass --no-apply-dynamic-relocs to restore pre-binutils-2.27 behaviour
|
|
# for relative relocs, since this leads to better Image compression
|
|
# with the relocation offsets always being zero.
|
|
LDFLAGS_vmlinux += -shared -Bsymbolic -z notext -z norelro \
|
|
$(call ld-option, --no-apply-dynamic-relocs)
|
|
endif
|
|
|
|
ifeq ($(CONFIG_ARM64_ERRATUM_843419),y)
|
|
ifeq ($(call ld-option, --fix-cortex-a53-843419),)
|
|
$(warning ld does not support --fix-cortex-a53-843419; kernel may be susceptible to erratum)
|
|
else
|
|
LDFLAGS_vmlinux += --fix-cortex-a53-843419
|
|
endif
|
|
endif
|
|
|
|
ifeq ($(CONFIG_ARM64_USE_LSE_ATOMICS), y)
|
|
ifneq ($(CONFIG_ARM64_LSE_ATOMICS), y)
|
|
$(warning LSE atomics not supported by binutils)
|
|
endif
|
|
endif
|
|
|
|
cc_has_k_constraint := $(call try-run,echo \
|
|
'int main(void) { \
|
|
asm volatile("and w0, w0, %w0" :: "K" (4294967295)); \
|
|
return 0; \
|
|
}' | $(CC) -S -x c -o "$$TMP" -,,-DCONFIG_CC_HAS_K_CONSTRAINT=1)
|
|
|
|
ifeq ($(CONFIG_BROKEN_GAS_INST),y)
|
|
$(warning Detected assembler with broken .inst; disassembly will be unreliable)
|
|
endif
|
|
|
|
KBUILD_CFLAGS += -mgeneral-regs-only \
|
|
$(compat_vdso) $(cc_has_k_constraint)
|
|
KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
|
|
KBUILD_CFLAGS += $(call cc-disable-warning, psabi)
|
|
KBUILD_AFLAGS += $(compat_vdso)
|
|
|
|
KBUILD_CFLAGS += $(call cc-option,-mabi=lp64)
|
|
KBUILD_AFLAGS += $(call cc-option,-mabi=lp64)
|
|
|
|
ifeq ($(CONFIG_STACKPROTECTOR_PER_TASK),y)
|
|
prepare: stack_protector_prepare
|
|
stack_protector_prepare: prepare0
|
|
$(eval KBUILD_CFLAGS += -mstack-protector-guard=sysreg \
|
|
-mstack-protector-guard-reg=sp_el0 \
|
|
-mstack-protector-guard-offset=$(shell \
|
|
awk '{if ($$2 == "TSK_STACK_CANARY") print $$3;}' \
|
|
include/generated/asm-offsets.h))
|
|
endif
|
|
|
|
ifeq ($(CONFIG_ARM64_PTR_AUTH),y)
|
|
branch-prot-flags-$(CONFIG_CC_HAS_SIGN_RETURN_ADDRESS) := -msign-return-address=all
|
|
branch-prot-flags-$(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET) := -mbranch-protection=pac-ret+leaf
|
|
# -march=armv8.3-a enables the non-nops instructions for PAC, to avoid the
|
|
# compiler to generate them and consequently to break the single image contract
|
|
# we pass it only to the assembler. This option is utilized only in case of non
|
|
# integrated assemblers.
|
|
branch-prot-flags-$(CONFIG_AS_HAS_PAC) += -Wa,-march=armv8.3-a
|
|
KBUILD_CFLAGS += $(branch-prot-flags-y)
|
|
endif
|
|
|
|
ifeq ($(CONFIG_CPU_BIG_ENDIAN), y)
|
|
KBUILD_CPPFLAGS += -mbig-endian
|
|
CHECKFLAGS += -D__AARCH64EB__
|
|
AS += -EB
|
|
# Prefer the baremetal ELF build target, but not all toolchains include
|
|
# it so fall back to the standard linux version if needed.
|
|
KBUILD_LDFLAGS += -EB $(call ld-option, -maarch64elfb, -maarch64linuxb)
|
|
UTS_MACHINE := aarch64_be
|
|
else
|
|
KBUILD_CPPFLAGS += -mlittle-endian
|
|
CHECKFLAGS += -D__AARCH64EL__
|
|
AS += -EL
|
|
# Same as above, prefer ELF but fall back to linux target if needed.
|
|
KBUILD_LDFLAGS += -EL $(call ld-option, -maarch64elf, -maarch64linux)
|
|
UTS_MACHINE := aarch64
|
|
endif
|
|
|
|
CHECKFLAGS += -D__aarch64__
|
|
|
|
ifeq ($(CONFIG_ARM64_MODULE_PLTS),y)
|
|
KBUILD_LDS_MODULE += $(srctree)/arch/arm64/kernel/module.lds
|
|
endif
|
|
|
|
ifeq ($(CONFIG_DYNAMIC_FTRACE_WITH_REGS),y)
|
|
KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY
|
|
CC_FLAGS_FTRACE := -fpatchable-function-entry=2
|
|
endif
|
|
|
|
# Default value
|
|
head-y := arch/arm64/kernel/head.o
|
|
|
|
# The byte offset of the kernel image in RAM from the start of RAM.
|
|
ifeq ($(CONFIG_ARM64_RANDOMIZE_TEXT_OFFSET), y)
|
|
TEXT_OFFSET := $(shell awk "BEGIN {srand(); printf \"0x%06x\n\", \
|
|
int(2 * 1024 * 1024 / (2 ^ $(CONFIG_ARM64_PAGE_SHIFT)) * \
|
|
rand()) * (2 ^ $(CONFIG_ARM64_PAGE_SHIFT))}")
|
|
else
|
|
TEXT_OFFSET := 0x00080000
|
|
endif
|
|
|
|
ifeq ($(CONFIG_KASAN_SW_TAGS), y)
|
|
KASAN_SHADOW_SCALE_SHIFT := 4
|
|
else
|
|
KASAN_SHADOW_SCALE_SHIFT := 3
|
|
endif
|
|
|
|
KBUILD_CFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
|
|
KBUILD_CPPFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
|
|
KBUILD_AFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
|
|
|
|
export TEXT_OFFSET GZFLAGS
|
|
|
|
core-y += arch/arm64/
|
|
libs-y := arch/arm64/lib/ $(libs-y)
|
|
core-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
|
|
|
|
# Default target when executing plain make
|
|
boot := arch/arm64/boot
|
|
KBUILD_IMAGE := $(boot)/Image.gz
|
|
|
|
all: Image.gz
|
|
|
|
|
|
Image: vmlinux
|
|
$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
|
|
|
|
Image.%: Image
|
|
$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
|
|
|
|
zinstall install:
|
|
$(Q)$(MAKE) $(build)=$(boot) $@
|
|
|
|
PHONY += vdso_install
|
|
vdso_install:
|
|
$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso $@
|
|
|
|
# We use MRPROPER_FILES and CLEAN_FILES now
|
|
archclean:
|
|
$(Q)$(MAKE) $(clean)=$(boot)
|
|
|
|
ifeq ($(KBUILD_EXTMOD),)
|
|
# We need to generate vdso-offsets.h before compiling certain files in kernel/.
|
|
# In order to do that, we should use the archprepare target, but we can't since
|
|
# asm-offsets.h is included in some files used to generate vdso-offsets.h, and
|
|
# asm-offsets.h is built in prepare0, for which archprepare is a dependency.
|
|
# Therefore we need to generate the header after prepare0 has been made, hence
|
|
# this hack.
|
|
prepare: vdso_prepare
|
|
vdso_prepare: prepare0
|
|
$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso include/generated/vdso-offsets.h
|
|
$(if $(CONFIG_COMPAT_VDSO),$(Q)$(MAKE) \
|
|
$(build)=arch/arm64/kernel/vdso32 \
|
|
include/generated/vdso32-offsets.h)
|
|
endif
|
|
|
|
define archhelp
|
|
echo '* Image.gz - Compressed kernel image (arch/$(ARCH)/boot/Image.gz)'
|
|
echo ' Image - Uncompressed kernel image (arch/$(ARCH)/boot/Image)'
|
|
echo ' install - Install uncompressed kernel'
|
|
echo ' zinstall - Install compressed kernel'
|
|
echo ' Install using (your) ~/bin/installkernel or'
|
|
echo ' (distribution) /sbin/installkernel or'
|
|
echo ' install to $$(INSTALL_PATH) and run lilo'
|
|
endef
|