1# SPDX-License-Identifier: GPL-2.0 2# 3# Building vDSO images for x86. 4# 5 6vdso-install-y += vdso.so 7 8# files to link into the vdso 9vobjs-y := vdso-note.o um_vdso.o 10 11# files to link into kernel 12obj-y += vdso.o vma.o 13 14vobjs := $(foreach F,$(vobjs-y),$(obj)/$F) 15 16$(obj)/vdso.o: $(obj)/vdso.so 17 18targets += vdso.so vdso.so.dbg vdso.lds $(vobjs-y) 19 20CPPFLAGS_vdso.lds += -P -C 21 22VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \ 23 -Wl,-z,max-page-size=4096 24 25$(obj)/vdso.o: $(src)/vdso.S $(obj)/vdso.so 26 27$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(vobjs) FORCE 28 $(call if_changed,vdso) 29 30$(obj)/%.so: OBJCOPYFLAGS := -S 31$(obj)/%.so: $(obj)/%.so.dbg FORCE 32 $(call if_changed,objcopy) 33 34# 35# Don't omit frame pointers for ease of userspace debugging, but do 36# optimize sibling calls. 37# 38CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \ 39 $(filter -g%,$(KBUILD_CFLAGS)) -fno-stack-protector \ 40 -fno-omit-frame-pointer -foptimize-sibling-calls 41 42$(vobjs): KBUILD_CFLAGS += $(CFL) 43 44# 45# vDSO code runs in userspace and -pg doesn't help with profiling anyway. 46# 47CFLAGS_REMOVE_vdso-note.o = -pg -fprofile-arcs -ftest-coverage 48CFLAGS_REMOVE_um_vdso.o = -pg -fprofile-arcs -ftest-coverage 49 50# 51# The DSO images are built using a special linker script. 52# 53quiet_cmd_vdso = VDSO $@ 54 cmd_vdso = $(CC) -nostdlib -o $@ \ 55 $(CC_FLAGS_LTO) $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \ 56 -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^) 57 58VDSO_LDFLAGS = -fPIC -shared -Wl,--hash-style=sysv -z noexecstack -Wl,--no-undefined 59