1# SPDX-License-Identifier: GPL-2.0-only 2# Copied from arch/tile/kernel/vdso/Makefile 3 4# Include the generic Makefile to check the built vdso. 5include $(srctree)/lib/vdso/Makefile 6# Symbols present in the vdso 7vdso-syms = rt_sigreturn 8ifdef CONFIG_64BIT 9vdso-syms += vgettimeofday 10endif 11vdso-syms += getcpu 12vdso-syms += flush_icache 13vdso-syms += hwprobe 14vdso-syms += sys_hwprobe 15 16# Files to link into the vdso 17obj-vdso = $(patsubst %, %.o, $(vdso-syms)) note.o 18 19ccflags-y := -fno-stack-protector 20ccflags-y += -DDISABLE_BRANCH_PROFILING 21ccflags-y += -fno-builtin 22 23ifneq ($(c-gettimeofday-y),) 24 CFLAGS_vgettimeofday.o += -fPIC -include $(c-gettimeofday-y) 25endif 26 27CFLAGS_hwprobe.o += -fPIC 28 29# Build rules 30targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.lds 31obj-vdso := $(addprefix $(obj)/, $(obj-vdso)) 32 33obj-y += vdso.o 34CPPFLAGS_vdso.lds += -P -C -U$(ARCH) 35ifneq ($(filter vgettimeofday, $(vdso-syms)),) 36CPPFLAGS_vdso.lds += -DHAS_VGETTIMEOFDAY 37endif 38 39# Disable -pg to prevent insert call site 40CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) 41 42# Disable profiling and instrumentation for VDSO code 43GCOV_PROFILE := n 44KCOV_INSTRUMENT := n 45KASAN_SANITIZE := n 46UBSAN_SANITIZE := n 47 48# Force dependency 49$(obj)/vdso.o: $(obj)/vdso.so 50 51# link rule for the .so file, .lds has to be first 52$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE 53 $(call if_changed,vdsold) 54LDFLAGS_vdso.so.dbg = -shared -S -soname=linux-vdso.so.1 \ 55 --build-id=sha1 --hash-style=both --eh-frame-hdr 56 57# strip rule for the .so file 58$(obj)/%.so: OBJCOPYFLAGS := -S 59$(obj)/%.so: $(obj)/%.so.dbg FORCE 60 $(call if_changed,objcopy) 61 62# Generate VDSO offsets using helper script 63gen-vdsosym := $(srctree)/$(src)/gen_vdso_offsets.sh 64quiet_cmd_vdsosym = VDSOSYM $@ 65 cmd_vdsosym = $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@ 66 67include/generated/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE 68 $(call if_changed,vdsosym) 69 70# actual build commands 71# The DSO images are built using a special linker script 72# Make sure only to export the intended __vdso_xxx symbol offsets. 73quiet_cmd_vdsold = VDSOLD $@ 74 cmd_vdsold = $(LD) $(ld_flags) -T $(filter-out FORCE,$^) -o $@.tmp && \ 75 $(OBJCOPY) $(patsubst %, -G __vdso_%, $(vdso-syms)) $@.tmp $@ && \ 76 rm $@.tmp 77