1# SPDX-License-Identifier: GPL-2.0 2# 3# Building vDSO images for x86. 4# 5 6# do not instrument on vdso because KASAN is not compatible with user mode 7KASAN_SANITIZE := n 8 9# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in. 10KCOV_INSTRUMENT := n 11 12VDSO64-y := y 13 14vdso-install-$(VDSO64-y) += vdso.so 15 16 17# files to link into the vdso 18vobjs-y := vdso-note.o um_vdso.o 19 20# files to link into kernel 21obj-$(VDSO64-y) += vdso.o vma.o 22 23vobjs := $(foreach F,$(vobjs-y),$(obj)/$F) 24 25$(obj)/vdso.o: $(obj)/vdso.so 26 27targets += vdso.so vdso.so.dbg vdso.lds $(vobjs-y) 28 29CPPFLAGS_vdso.lds += -P -C 30 31VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \ 32 -Wl,-z,max-page-size=4096 33 34$(obj)/vdso.o: $(src)/vdso.S $(obj)/vdso.so 35 36$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(vobjs) FORCE 37 $(call if_changed,vdso) 38 39$(obj)/%.so: OBJCOPYFLAGS := -S 40$(obj)/%.so: $(obj)/%.so.dbg FORCE 41 $(call if_changed,objcopy) 42 43# 44# Don't omit frame pointers for ease of userspace debugging, but do 45# optimize sibling calls. 46# 47CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \ 48 $(filter -g%,$(KBUILD_CFLAGS)) -fno-stack-protector \ 49 -fno-omit-frame-pointer -foptimize-sibling-calls 50 51$(vobjs): KBUILD_CFLAGS += $(CFL) 52 53# 54# vDSO code runs in userspace and -pg doesn't help with profiling anyway. 55# 56CFLAGS_REMOVE_vdso-note.o = -pg -fprofile-arcs -ftest-coverage 57CFLAGS_REMOVE_um_vdso.o = -pg -fprofile-arcs -ftest-coverage 58 59# 60# The DSO images are built using a special linker script. 61# 62quiet_cmd_vdso = VDSO $@ 63 cmd_vdso = $(CC) -nostdlib -o $@ \ 64 $(CC_FLAGS_LTO) $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \ 65 -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^) && \ 66 sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@' 67 68VDSO_LDFLAGS = -fPIC -shared -Wl,--hash-style=sysv -z noexecstack 69GCOV_PROFILE := n 70