linux/arch/arm64/kernel/Makefile
Ard Biesheuvel 3b619e22c4 arm64: implement dynamic shadow call stack for Clang
Implement dynamic shadow call stack support on Clang, by parsing the
unwind tables at init time to locate all occurrences of PACIASP/AUTIASP
instructions, and replacing them with the shadow call stack push and pop
instructions, respectively.

This is useful because the overhead of the shadow call stack is
difficult to justify on hardware that implements pointer authentication
(PAC), and given that the PAC instructions are executed as NOPs on
hardware that doesn't, we can just replace them without breaking
anything. As PACIASP/AUTIASP are guaranteed to be paired with respect to
manipulations of the return address, replacing them 1:1 with shadow call
stack pushes and pops is guaranteed to result in the desired behavior.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Sami Tolvanen <samitolvanen@google.com>
Link: https://lore.kernel.org/r/20221027155908.1940624-4-ardb@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2022-11-09 18:06:35 +00:00

100 lines
3.7 KiB
Makefile

# SPDX-License-Identifier: GPL-2.0
#
# Makefile for the linux kernel.
#
CFLAGS_armv8_deprecated.o := -I$(src)
CFLAGS_REMOVE_ftrace.o = $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_insn.o = $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_return_address.o = $(CC_FLAGS_FTRACE)
# Remove stack protector to avoid triggering unneeded stack canary
# checks due to randomize_kstack_offset.
CFLAGS_REMOVE_syscall.o = -fstack-protector -fstack-protector-strong
CFLAGS_syscall.o += -fno-stack-protector
# When KASAN is enabled, a stack trace is recorded for every alloc/free, which
# can significantly impact performance. Avoid instrumenting the stack trace
# collection code to minimize this impact.
KASAN_SANITIZE_stacktrace.o := n
# It's not safe to invoke KCOV when portions of the kernel environment aren't
# available or are out-of-sync with HW state. Since `noinstr` doesn't always
# inhibit KCOV instrumentation, disable it for the entire compilation unit.
KCOV_INSTRUMENT_entry-common.o := n
KCOV_INSTRUMENT_idle.o := n
# Object file lists.
obj-y := debug-monitors.o entry.o irq.o fpsimd.o \
entry-common.o entry-fpsimd.o process.o ptrace.o \
setup.o signal.o sys.o stacktrace.o time.o traps.o \
io.o vdso.o hyp-stub.o psci.o cpu_ops.o \
return_address.o cpuinfo.o cpu_errata.o \
cpufeature.o alternative.o cacheinfo.o \
smp.o smp_spin_table.o topology.o smccc-call.o \
syscall.o proton-pack.o idreg-override.o idle.o \
patching.o
targets += efi-entry.o
OBJCOPYFLAGS := --prefix-symbols=__efistub_
$(obj)/%.stub.o: $(obj)/%.o FORCE
$(call if_changed,objcopy)
obj-$(CONFIG_COMPAT) += sys32.o signal32.o \
sys_compat.o
obj-$(CONFIG_COMPAT) += sigreturn32.o
obj-$(CONFIG_COMPAT_ALIGNMENT_FIXUPS) += compat_alignment.o
obj-$(CONFIG_KUSER_HELPERS) += kuser32.o
obj-$(CONFIG_FUNCTION_TRACER) += ftrace.o entry-ftrace.o
obj-$(CONFIG_MODULES) += module.o
obj-$(CONFIG_ARM64_MODULE_PLTS) += module-plts.o
obj-$(CONFIG_PERF_EVENTS) += perf_regs.o perf_callchain.o
obj-$(CONFIG_HW_PERF_EVENTS) += perf_event.o
obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o
obj-$(CONFIG_CPU_PM) += sleep.o suspend.o
obj-$(CONFIG_CPU_IDLE) += cpuidle.o
obj-$(CONFIG_JUMP_LABEL) += jump_label.o
obj-$(CONFIG_KGDB) += kgdb.o
obj-$(CONFIG_EFI) += efi.o efi-entry.stub.o \
efi-rt-wrapper.o
obj-$(CONFIG_PCI) += pci.o
obj-$(CONFIG_ARMV8_DEPRECATED) += armv8_deprecated.o
obj-$(CONFIG_ACPI) += acpi.o
obj-$(CONFIG_ACPI_NUMA) += acpi_numa.o
obj-$(CONFIG_ARM64_ACPI_PARKING_PROTOCOL) += acpi_parking_protocol.o
obj-$(CONFIG_PARAVIRT) += paravirt.o
obj-$(CONFIG_RANDOMIZE_BASE) += kaslr.o pi/
obj-$(CONFIG_HIBERNATION) += hibernate.o hibernate-asm.o
obj-$(CONFIG_ELF_CORE) += elfcore.o
obj-$(CONFIG_KEXEC_CORE) += machine_kexec.o relocate_kernel.o \
cpu-reset.o
obj-$(CONFIG_KEXEC_FILE) += machine_kexec_file.o kexec_image.o
obj-$(CONFIG_ARM64_RELOC_TEST) += arm64-reloc-test.o
arm64-reloc-test-y := reloc_test_core.o reloc_test_syms.o
obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
obj-$(CONFIG_CRASH_CORE) += crash_core.o
obj-$(CONFIG_ARM_SDE_INTERFACE) += sdei.o
obj-$(CONFIG_ARM64_PTR_AUTH) += pointer_auth.o
obj-$(CONFIG_ARM64_MTE) += mte.o
obj-y += vdso-wrap.o
obj-$(CONFIG_COMPAT_VDSO) += vdso32-wrap.o
obj-$(CONFIG_UNWIND_PATCH_PAC_INTO_SCS) += patch-scs.o
CFLAGS_patch-scs.o += -mbranch-protection=none
# Force dependency (vdso*-wrap.S includes vdso.so through incbin)
$(obj)/vdso-wrap.o: $(obj)/vdso/vdso.so
$(obj)/vdso32-wrap.o: $(obj)/vdso32/vdso.so
obj-y += probes/
obj-y += head.o
extra-y += vmlinux.lds
ifeq ($(CONFIG_DEBUG_EFI),y)
AFLAGS_head.o += -DVMLINUX_PATH="\"$(realpath $(objtree)/vmlinux)\""
endif
# for cleaning
subdir- += vdso vdso32