x86_64: install unstripped copies of compat vdso on disk

From: Roland McGrath <roland@redhat.com>

This keeps an unstripped copy of the 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.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andi Kleen <ak@suse.de>

 arch/x86_64/Makefile      |    7 ++++++-
 arch/x86_64/ia32/Makefile |   25 +++++++++++++++++++++----
 2 files changed, 27 insertions(+), 5 deletions(-)

Index: linux/arch/x86_64/Makefile
===================================================================
--- linux.orig/arch/x86_64/Makefile
+++ linux/arch/x86_64/Makefile
@@ -109,9 +109,14 @@ bzdisk: vmlinux
 fdimage fdimage144 fdimage288 isoimage: vmlinux
 	$(Q)$(MAKE) $(build)=$(boot) BOOTIMAGE=$(BOOTIMAGE) $@
 
-install:
+install: vdso_install
 	$(Q)$(MAKE) $(build)=$(boot) BOOTIMAGE=$(BOOTIMAGE) $@ 
 
+vdso_install:
+ifeq ($(CONFIG_IA32_EMULATION),y)
+	$(Q)$(MAKE) $(build)=arch/x86_64/ia32 $@
+endif
+
 archclean:
 	$(Q)$(MAKE) $(clean)=$(boot)
 
Index: linux/arch/x86_64/ia32/Makefile
===================================================================
--- linux.orig/arch/x86_64/ia32/Makefile
+++ linux/arch/x86_64/ia32/Makefile
@@ -18,18 +18,35 @@ $(obj)/syscall32_syscall.o: \
 	$(foreach F,sysenter syscall,$(obj)/vsyscall-$F.so)
 
 # Teach kbuild about targets
-targets := $(foreach F,sysenter syscall,vsyscall-$F.o vsyscall-$F.so)
+targets := $(foreach F,$(addprefix vsyscall-,sysenter syscall),\
+		     $F.o $F.so $F.so.dbg)
 
 # The DSO images are built using a special linker script
 quiet_cmd_syscall = SYSCALL $@
-      cmd_syscall = $(CC) -m32 -nostdlib -shared -s \
+      cmd_syscall = $(CC) -m32 -nostdlib -shared \
 			  $(call ld-option, -Wl$(comma)--hash-style=sysv) \
 			   -Wl,-soname=linux-gate.so.1 -o $@ \
 			   -Wl,-T,$(filter-out FORCE,$^)
 
-$(obj)/vsyscall-sysenter.so $(obj)/vsyscall-syscall.so: \
-$(obj)/vsyscall-%.so: $(src)/vsyscall.lds $(obj)/vsyscall-%.o FORCE
+$(obj)/%.so: OBJCOPYFLAGS := -S
+$(obj)/%.so: $(obj)/%.so.dbg FORCE
+	$(call if_changed,objcopy)
+
+$(obj)/vsyscall-sysenter.so.dbg $(obj)/vsyscall-syscall.so.dbg: \
+$(obj)/vsyscall-%.so.dbg: $(src)/vsyscall.lds $(obj)/vsyscall-%.o FORCE
 	$(call if_changed,syscall)
 
 AFLAGS_vsyscall-sysenter.o = -m32 -Wa,-32
 AFLAGS_vsyscall-syscall.o = -m32 -Wa,-32
+
+vdsos := vdso32-sysenter.so vdso32-syscall.so
+
+quiet_cmd_vdso_install = INSTALL $@
+      cmd_vdso_install = cp $(@:vdso32-%.so=$(obj)/vsyscall-%.so.dbg) \
+			    $(MODLIB)/vdso/$@
+
+$(vdsos):
+	@mkdir -p $(MODLIB)/vdso
+	$(call cmd,vdso_install)
+
+vdso_install: $(vdsos)