Merge branch 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, vdso: Don't quote $nm in the script for checking vdso references
  x86, vdso: Error out if the vdso contains external references

2 files changed, 12 insertions, 1 deletions

diff --git a/arch/x86/vdso/Makefile b/arch/x86/vdso/Makefile
index 6b4ffedb93c..4a2afa1bac5 100644
--- a/arch/x86/vdso/Makefile
+++ b/arch/x86/vdso/Makefile
@@ -120,7 +120,8 @@ $(obj)/vdso32-syms.lds: $(vdso32.so-y:%=$(obj)/vdso32-%-syms.lds) FORCE
 quiet_cmd_vdso = VDSO    $@
       cmd_vdso = $(CC) -nostdlib -o $@ \
                        $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
-                       -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^)
+                       -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^) && \
+                 sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
 
 VDSO_LDFLAGS = -fPIC -shared $(call cc-ldoption, -Wl$(comma)--hash-style=sysv)
 GCOV_PROFILE := n
diff --git a/arch/x86/vdso/checkundef.sh b/arch/x86/vdso/checkundef.sh
new file mode 100755
index 00000000000..7ee90a9b549
--- /dev/null
+++ b/arch/x86/vdso/checkundef.sh
@@ -0,0 +1,10 @@
+#!/bin/sh
+nm="$1"
+file="$2"
+$nm "$file" | grep '^ *U' > /dev/null 2>&1
+if [ $? -eq 1 ]; then
+    exit 0
+else
+    echo "$file: undefined symbols found" >&2
+    exit 1
+fi