# # x86-64 vDSO. # # files to link into the vdso # vdso-start.o has to be first vobjs-y := vdso-start.o vdso-note.o vclock_gettime.o vgetcpu.o vvar.o # files to link into kernel obj-y := vma.o vdso.o vdso-syms.o vobjs := $(foreach F,$(vobjs-y),$(obj)/$F) $(obj)/vdso.o: $(obj)/vdso.so targets += vdso.so vdso.lds $(vobjs-y) vdso-syms.o # The DSO images are built using a special linker script. quiet_cmd_syscall = SYSCALL $@ cmd_syscall = $(CC) -m elf_x86_64 -nostdlib $(SYSCFLAGS_$(@F)) \ -Wl,-T,$(filter-out FORCE,$^) -o $@ export CPPFLAGS_vdso.lds += -P -C -U$(ARCH) vdso-flags = -fPIC -shared -Wl,-soname=linux-vdso.so.1 \ $(call ld-option, -Wl$(comma)--hash-style=sysv) \ -Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096 SYSCFLAGS_vdso.so = $(vdso-flags) $(obj)/vdso.o: $(src)/vdso.S $(obj)/vdso.so $(obj)/vdso.so: $(src)/vdso.lds $(vobjs) FORCE $(call if_changed,syscall) CF := $(PROFILING) -mcmodel=small -fPIC -g0 -O2 -fasynchronous-unwind-tables -m64 $(obj)/vclock_gettime.o: CFLAGS = $(CF) $(obj)/vgetcpu.o: CFLAGS = $(CF) # We also create a special relocatable object that should mirror the symbol # table and layout of the linked DSO. With ld -R we can then refer to # these symbols in the kernel code rather than hand-coded addresses. extra-y += vdso-syms.o $(obj)/built-in.o: $(obj)/vdso-syms.o $(obj)/built-in.o: ld_flags += -R $(obj)/vdso-syms.o SYSCFLAGS_vdso-syms.o = -r -d $(obj)/vdso-syms.o: $(src)/vdso.lds $(vobjs) FORCE $(call if_changed,syscall)