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# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in. 34KCOV_INSTRUMENT := n 35 36# Force dependency 37$(obj)/vdso.o : $(obj)/vdso.so 38 39# Link rule for the .so file 40$(obj)/vdso.so.raw: $(src)/vdso.lds $(obj-vdso) FORCE 41 $(call if_changed,vdsold) 42 43$(obj)/vdso.so.dbg: $(obj)/vdso.so.raw $(obj)/vdsomunge FORCE 44 $(call if_changed,vdsomunge) 45 46# Strip rule for the .so file 47$(obj)/%.so: OBJCOPYFLAGS := -S 48$(obj)/%.so: $(obj)/%.so.dbg FORCE 49 $(call if_changed,objcopy) 50 51# Actual build commands 52quiet_cmd_vdsold = VDSO $@ 53 cmd_vdsold = $(CC) $(c_flags) $(VDSO_LDFLAGS) \ 54 -Wl,-T $(filter %.lds,$^) $(filter %.o,$^) -o $@ 55 56quiet_cmd_vdsomunge = MUNGE $@ 57 cmd_vdsomunge = $(objtree)/$(obj)/vdsomunge $< $@ 58 59# 60# Install the unstripped copy of vdso.so.dbg. If our toolchain 61# supports build-id, install .build-id links as well. 62# 63# Cribbed from arch/x86/vdso/Makefile. 64# 65quiet_cmd_vdso_install = INSTALL $< 66define cmd_vdso_install 67 cp $< "$(MODLIB)/vdso/vdso.so"; \ 68 if readelf -n $< | grep -q 'Build ID'; then \ 69 buildid=`readelf -n $< |grep 'Build ID' |sed -e 's/^.*Build ID: \(.*\)$$/\1/'`; \ 70 first=`echo $$buildid | cut -b-2`; \ 71 last=`echo $$buildid | cut -b3-`; \ 72 mkdir -p "$(MODLIB)/vdso/.build-id/$$first"; \ 73 ln -sf "../../vdso.so" "$(MODLIB)/vdso/.build-id/$$first/$$last.debug"; \ 74 fi 75endef 76 77$(MODLIB)/vdso: FORCE 78 @mkdir -p $(MODLIB)/vdso 79 80PHONY += vdso_install 81vdso_install: $(obj)/vdso.so.dbg $(MODLIB)/vdso 82 $(call cmd,vdso_install) 83