x86: Install unstripped copy of 64bit vdso to disk

This keeps an unstripped copy of the 64bit vDSO images built before they are
stripped and embedded in the kernel.  The unstripped copies get installed
in $(MODLIB)/vdso/ by "make install" (or you can explicitly use the
subtarget "make vdso_install").  These files can be useful when they
contain source-level debugging information.

[ tglx: arch/x86 adaptation ]
Signed-off-by: NRoland McGrath <roland@redhat.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

arch/x86/vdso/Makefile

@@ -13,7 +13,7 @@ vobjs := $(foreach F,$(vobjs-y),$(obj)/$F)
 
 $(obj)/vdso.o: $(obj)/vdso.so
 
-targets += vdso.so vdso.lds $(vobjs-y) vdso-syms.o
+targets += vdso.so vdso.so.dbg vdso.lds $(vobjs-y) vdso-syms.o
 
 # The DSO images are built using a special linker script.
 quiet_cmd_syscall = SYSCALL $@
@@ -26,12 +26,19 @@ 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)
+SYSCFLAGS_vdso.so.dbg = $(vdso-flags)
 
 $(obj)/vdso.o: $(src)/vdso.S $(obj)/vdso.so
 
 $(obj)/vdso.so: $(src)/vdso.lds $(vobjs) FORCE
+
+$(obj)/vdso.so.dbg: $(src)/vdso.lds $(vobjs) FORCE
 	$(call if_changed,syscall)
 
+$(obj)/%.so: OBJCOPYFLAGS := -S
+$(obj)/%.so: $(obj)/%.so.dbg FORCE
+	$(call if_changed,objcopy)
+
 CFL := $(PROFILING) -mcmodel=small -fPIC -g0 -O2 -fasynchronous-unwind-tables -m64
 
 $(obj)/vclock_gettime.o: KBUILD_CFLAGS = $(CFL)
@@ -47,3 +54,11 @@ $(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)
+
+quiet_cmd_vdso_install = INSTALL $@
+      cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
+vdso.so:
+	@mkdir -p $(MODLIB)/vdso
+	$(call cmd,vdso_install)
+
+vdso_install: vdso.so

arch/x86_64/Makefile

@@ -117,6 +117,7 @@ vdso_install:
 ifeq ($(CONFIG_IA32_EMULATION),y)
 	$(Q)$(MAKE) $(build)=arch/x86/ia32 $@
 endif
+	$(Q)$(MAKE) $(build)=arch/x86/vdso $@
 
 archclean:
 	$(Q)rm -rf $(objtree)/arch/x86_64/boot