1# SPDX-License-Identifier: GPL-2.0-only 2 3# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before 4# the inclusion of generic Makefile. 5ARCH_REL_TYPE_ABS := R_CKCORE_ADDR32|R_CKCORE_JUMP_SLOT 6include $(srctree)/lib/vdso/Makefile 7 8# Symbols present in the vdso 9vdso-syms += rt_sigreturn 10vdso-syms += vgettimeofday 11 12# Files to link into the vdso 13obj-vdso = $(patsubst %, %.o, $(vdso-syms)) note.o 14 15ifneq ($(c-gettimeofday-y),) 16 CFLAGS_vgettimeofday.o += -include $(c-gettimeofday-y) 17endif 18 19ccflags-y := -fno-stack-protector -DBUILD_VDSO32 20 21# Build rules 22targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.lds vdso-dummy.o 23obj-vdso := $(addprefix $(obj)/, $(obj-vdso)) 24 25obj-y += vdso.o vdso-syms.o 26CPPFLAGS_vdso.lds += -P -C -U$(ARCH) 27 28# Disable gcov profiling for VDSO code 29GCOV_PROFILE := n 30KCOV_INSTRUMENT := n 31 32# Force dependency 33$(obj)/vdso.o: $(obj)/vdso.so 34 35SYSCFLAGS_vdso.so.dbg = $(c_flags) 36$(obj)/vdso.so.dbg: $(src)/vdso.lds $(obj-vdso) FORCE 37 $(call if_changed,vdsold) 38SYSCFLAGS_vdso.so.dbg = -shared -s -Wl,-soname=linux-vdso.so.1 \ 39 -Wl,--build-id=sha1 -Wl,--hash-style=both 40 41$(obj)/vdso-syms.S: $(obj)/vdso.so FORCE 42 $(call if_changed,so2s) 43 44# strip rule for the .so file 45$(obj)/%.so: OBJCOPYFLAGS := -S 46$(obj)/%.so: $(obj)/%.so.dbg FORCE 47 $(call if_changed,objcopy) 48 49# actual build commands 50# The DSO images are built using a special linker script 51# Make sure only to export the intended __vdso_xxx symbol offsets. 52quiet_cmd_vdsold = VDSOLD $@ 53 cmd_vdsold = $(CC) $(KBUILD_CFLAGS) $(call cc-option, -no-pie) -nostdlib -nostartfiles $(SYSCFLAGS_$(@F)) \ 54 -Wl,-T,$(filter-out FORCE,$^) -o $@.tmp && \ 55 $(CROSS_COMPILE)objcopy \ 56 $(patsubst %, -G __vdso_%, $(vdso-syms)) $@.tmp $@ && \ 57 rm $@.tmp 58 59# Extracts symbol offsets from the VDSO, converting them into an assembly file 60# that contains the same symbols at the same offsets. 61quiet_cmd_so2s = SO2S $@ 62 cmd_so2s = $(NM) -D $< | $(srctree)/$(src)/so2s.sh > $@ 63 64# install commands for the unstripped file 65quiet_cmd_vdso_install = INSTALL $@ 66 cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@ 67 68vdso.so: $(obj)/vdso.so.dbg 69 @mkdir -p $(MODLIB)/vdso 70 $(call cmd,vdso_install) 71 72vdso_install: vdso.so 73