x86/vdso: Fix vdso_install

"make vdso_install" installs unstripped versions of the vdso objects
for the benefit of the debugger.  This was broken by checkin:

6f121e5 x86, vdso: Reimplement vdso.so preparation in build-time C

The filenames are different now, so update the Makefile to cope.

This still installs the 64-bit vdso as vdso64.so.  We believe this
will be okay, as the only known user is a patched gdb which is known
to use build-ids, but if it turns out to be a problem we may have to
add a link.

Inspired by a patch from Sam Ravnborg.

Acked-by: Sam Ravnborg <[email protected]>
Reported-by: Josh Boyer <[email protected]>
Tested-by: Josh Boyer <[email protected]>
Signed-off-by: Andy Lutomirski <[email protected]>
Link: http://lkml.kernel.org/r/b10299edd8ba98d17e07dafcd895b8ecf4d99eff.1402586707.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <[email protected]>

arch/x86/vdso/Makefile

@@ -9,11 +9,6 @@ VDSOX32-$(CONFIG_X86_X32_ABI)	:= y
 VDSO32-$(CONFIG_X86_32)		:= y
 VDSO32-$(CONFIG_COMPAT)		:= y
 
-vdso-install-$(VDSO64-y)	+= vdso.so
-vdso-install-$(VDSOX32-y)	+= vdsox32.so
-vdso-install-$(VDSO32-y)	+= $(vdso32-images)
-
-
 # files to link into the vdso
 vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o vdso-fakesections.o
 vobjs-nox32 := vdso-fakesections.o
@@ -178,15 +173,20 @@ VDSO_LDFLAGS = -fPIC -shared $(call cc-ldoption, -Wl$(comma)--hash-style=sysv) \
 GCOV_PROFILE := n
 
 #
-# Install the unstripped copy of vdso*.so listed in $(vdso-install-y).
+# Install the unstripped copies of vdso*.so.
 #
-quiet_cmd_vdso_install = INSTALL $@
-      cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
-$(vdso-install-y): %.so: $(obj)/%.so.dbg FORCE
+quiet_cmd_vdso_install = INSTALL $(@:install_%=%)
+      cmd_vdso_install = cp $< $(MODLIB)/vdso/$(@:install_%=%)
+
+vdso_img_insttargets := $(vdso_img_sodbg:%.dbg=install_%)
+
+$(MODLIB)/vdso: FORCE
 	@mkdir -p $(MODLIB)/vdso
+
+$(vdso_img_insttargets): install_%: $(obj)/%.dbg $(MODLIB)/vdso FORCE
 	$(call cmd,vdso_install)
 
-PHONY += vdso_install $(vdso-install-y)
-vdso_install: $(vdso-install-y)
+PHONY += vdso_install $(vdso_img_insttargets)
+vdso_install: $(vdso_img_insttargets) FORCE
 
 clean-files := vdso32-syscall* vdso32-sysenter* vdso32-int80*