1# SPDX-License-Identifier: GPL-2.0 2hostprogs-y := vdsomunge 3 4obj-vdso := vgettimeofday.o datapage.o 5 6# Build rules 7targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.so.raw vdso.lds 8obj-vdso := $(addprefix $(obj)/, $(obj-vdso)) 9 10ccflags-y := -fPIC -fno-common -fno-builtin -fno-stack-protector 11ccflags-y += -DDISABLE_BRANCH_PROFILING 12 13VDSO_LDFLAGS := -Wl,-Bsymbolic -Wl,--no-undefined -Wl,-soname=linux-vdso.so.1 14VDSO_LDFLAGS += -Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096 15VDSO_LDFLAGS += -nostdlib -shared 16VDSO_LDFLAGS += $(call cc-ldoption, -Wl$(comma)--hash-style=sysv) 17VDSO_LDFLAGS += $(call cc-ldoption, -Wl$(comma)--build-id) 18VDSO_LDFLAGS += $(call cc-ldoption, -fuse-ld=bfd) 19 20obj-$(CONFIG_VDSO) += vdso.o 21extra-$(CONFIG_VDSO) += vdso.lds 22CPPFLAGS_vdso.lds += -P -C -U$(ARCH) 23 24CFLAGS_REMOVE_vdso.o = -pg 25 26# Force -O2 to avoid libgcc dependencies 27CFLAGS_REMOVE_vgettimeofday.o = -pg -Os 28CFLAGS_vgettimeofday.o = -O2 29 30# Disable gcov profiling for VDSO code 31GCOV_PROFILE := n 32 33# Force dependency 34$(obj)/vdso.o : $(obj)/vdso.so 35 36# Link rule for the .so file 37$(obj)/vdso.so.raw: $(src)/vdso.lds $(obj-vdso) FORCE 38 $(call if_changed,vdsold) 39 40$(obj)/vdso.so.dbg: $(obj)/vdso.so.raw $(obj)/vdsomunge FORCE 41 $(call if_changed,vdsomunge) 42 43# Strip rule for the .so file 44$(obj)/%.so: OBJCOPYFLAGS := -S 45$(obj)/%.so: $(obj)/%.so.dbg FORCE 46 $(call if_changed,objcopy) 47 48# Actual build commands 49quiet_cmd_vdsold = VDSO $@ 50 cmd_vdsold = $(CC) $(c_flags) $(VDSO_LDFLAGS) \ 51 -Wl,-T $(filter %.lds,$^) $(filter %.o,$^) -o $@ 52 53quiet_cmd_vdsomunge = MUNGE $@ 54 cmd_vdsomunge = $(objtree)/$(obj)/vdsomunge $< $@ 55 56# 57# Install the unstripped copy of vdso.so.dbg. If our toolchain 58# supports build-id, install .build-id links as well. 59# 60# Cribbed from arch/x86/vdso/Makefile. 61# 62quiet_cmd_vdso_install = INSTALL $< 63define cmd_vdso_install 64 cp $< "$(MODLIB)/vdso/vdso.so"; \ 65 if readelf -n $< | grep -q 'Build ID'; then \ 66 buildid=`readelf -n $< |grep 'Build ID' |sed -e 's/^.*Build ID: \(.*\)$$/\1/'`; \ 67 first=`echo $$buildid | cut -b-2`; \ 68 last=`echo $$buildid | cut -b3-`; \ 69 mkdir -p "$(MODLIB)/vdso/.build-id/$$first"; \ 70 ln -sf "../../vdso.so" "$(MODLIB)/vdso/.build-id/$$first/$$last.debug"; \ 71 fi 72endef 73 74$(MODLIB)/vdso: FORCE 75 @mkdir -p $(MODLIB)/vdso 76 77PHONY += vdso_install 78vdso_install: $(obj)/vdso.so.dbg $(MODLIB)/vdso 79 $(call cmd,vdso_install) 80