1# SPDX-License-Identifier: GPL-2.0 2# 3# Building vDSO images for x86. 4# 5 6VDSO64-y := y 7 8vdso-install-$(VDSO64-y) += vdso.so 9 10 11# files to link into the vdso 12vobjs-y := vdso-note.o um_vdso.o 13 14# files to link into kernel 15obj-$(VDSO64-y) += vdso.o vma.o 16 17vobjs := $(foreach F,$(vobjs-y),$(obj)/$F) 18 19$(obj)/vdso.o: $(obj)/vdso.so 20 21targets += vdso.so vdso.so.dbg vdso.lds $(vobjs-y) 22 23CPPFLAGS_vdso.lds += -P -C 24 25VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \ 26 -Wl,-z,max-page-size=4096 27 28$(obj)/vdso.o: $(src)/vdso.S $(obj)/vdso.so 29 30$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(vobjs) FORCE 31 $(call if_changed,vdso) 32 33$(obj)/%.so: OBJCOPYFLAGS := -S 34$(obj)/%.so: $(obj)/%.so.dbg FORCE 35 $(call if_changed,objcopy) 36 37# 38# Don't omit frame pointers for ease of userspace debugging, but do 39# optimize sibling calls. 40# 41CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \ 42 $(filter -g%,$(KBUILD_CFLAGS)) -fno-stack-protector \ 43 -fno-omit-frame-pointer -foptimize-sibling-calls 44 45$(vobjs): KBUILD_CFLAGS += $(CFL) 46 47# 48# vDSO code runs in userspace and -pg doesn't help with profiling anyway. 49# 50CFLAGS_REMOVE_vdso-note.o = -pg -fprofile-arcs -ftest-coverage 51CFLAGS_REMOVE_um_vdso.o = -pg -fprofile-arcs -ftest-coverage 52 53# 54# The DSO images are built using a special linker script. 55# 56quiet_cmd_vdso = VDSO $@ 57 cmd_vdso = $(CC) -nostdlib -o $@ \ 58 $(CC_FLAGS_LTO) $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \ 59 -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^) && \ 60 sh $(src)/checkundef.sh '$(NM)' '$@' 61 62VDSO_LDFLAGS = -fPIC -shared -Wl,--hash-style=sysv -z noexecstack 63