| # SPDX-License-Identifier: GPL-2.0 | |
| # | |
| # Building a vDSO image for AArch64. | |
| # | |
| # Author: Will Deacon <will.deacon@arm.com> | |
| # Heavily based on the vDSO Makefiles for other archs. | |
| # | |
| # Include the generic Makefile to check the built vdso. | |
| include $(srctree)/lib/vdso/Makefile.include | |
| obj-vdso := vgettimeofday.o note.o sigreturn.o vgetrandom.o vgetrandom-chacha.o | |
| # Build rules | |
| targets := $(obj-vdso) vdso.so vdso.so.dbg | |
| obj-vdso := $(addprefix $(obj)/, $(obj-vdso)) | |
| btildflags-$(CONFIG_ARM64_BTI_KERNEL) += -z force-bti | |
| # -Bsymbolic has been added for consistency with arm, the compat vDSO and | |
| # potential future proofing if we end up with internal calls to the exported | |
| # routines, as x86 does (see 6f121e548f83 ("x86, vdso: Reimplement vdso.so | |
| # preparation in build-time C")). | |
| ldflags-y := -shared -soname=linux-vdso.so.1 \ | |
| -Bsymbolic --build-id=sha1 -n $(btildflags-y) | |
| ifdef CONFIG_LD_ORPHAN_WARN | |
| ldflags-y += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL) | |
| endif | |
| ldflags-y += -T | |
| ccflags-y := -fno-common -fno-builtin -fno-stack-protector -ffixed-x18 | |
| ccflags-y += -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO | |
| # -Wmissing-prototypes and -Wmissing-declarations are removed from | |
| # the CFLAGS to make possible to build the kernel with CONFIG_WERROR enabled. | |
| CC_FLAGS_REMOVE_VDSO := $(CC_FLAGS_FTRACE) -Os $(CC_FLAGS_SCS) \ | |
| $(RANDSTRUCT_CFLAGS) $(KSTACK_ERASE_CFLAGS) \ | |
| $(GCC_PLUGINS_CFLAGS) \ | |
| $(CC_FLAGS_LTO) $(CC_FLAGS_CFI) \ | |
| -Wmissing-prototypes -Wmissing-declarations | |
| CC_FLAGS_ADD_VDSO := -O2 -mcmodel=tiny -fasynchronous-unwind-tables $(CONFIG_CC_OPT_INLINE_MEMSET) | |
| CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_REMOVE_VDSO) | |
| CFLAGS_REMOVE_vgetrandom.o = $(CC_FLAGS_REMOVE_VDSO) | |
| CFLAGS_vgettimeofday.o = $(CC_FLAGS_ADD_VDSO) | |
| CFLAGS_vgetrandom.o = $(CC_FLAGS_ADD_VDSO) | |
| ifneq ($(c-gettimeofday-y),) | |
| CFLAGS_vgettimeofday.o += -include $(c-gettimeofday-y) | |
| endif | |
| ifneq ($(c-getrandom-y),) | |
| CFLAGS_vgetrandom.o += -include $(c-getrandom-y) | |
| endif | |
| targets += vdso.lds | |
| CPPFLAGS_vdso.lds += -P -C -U$(ARCH) | |
| # Link rule for the .so file, .lds has to be first | |
| $(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE | |
| $(call if_changed,vdsold_and_vdso_check) | |
| # Strip rule for the .so file | |
| $(obj)/%.so: OBJCOPYFLAGS := -S | |
| $(obj)/%.so: $(obj)/%.so.dbg FORCE | |
| $(call if_changed,objcopy) | |
| # Generate VDSO offsets using helper script | |
| gen-vdsosym := $(src)/gen_vdso_offsets.sh | |
| quiet_cmd_vdsosym = VDSOSYM $@ | |
| cmd_vdsosym = $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@ | |
| include/generated/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE | |
| $(call if_changed,vdsosym) | |
| # Actual build commands | |
| quiet_cmd_vdsold_and_vdso_check = LD $@ | |
| cmd_vdsold_and_vdso_check = $(cmd_ld); $(cmd_vdso_check) |