sparc: Validate VDSO for undefined symbols.

There should be no undefined symbols in the resulting VDSO image(s).

On sparc, fixed register usage can result in undefined symbols ending
up in the image.  To combat this, we do two things:

1) Define current_thread_info() specially when BUILD_DSO.

2) Ignore "#scratch" register undefined symbols in the output.

Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/arch/sparc/include/asm/thread_info_64.h b/arch/sparc/include/asm/thread_info_64.h
index 7fb6763..2025547 100644 (file)
--- a/arch/sparc/include/asm/thread_info_64.h
+++ b/arch/sparc/include/asm/thread_info_64.h
@@ -121,8 +121,12 @@ struct thread_info {
 }
 
 /* how to get the thread information struct from C */
+#ifndef BUILD_VDSO
 register struct thread_info *current_thread_info_reg asm("g6");
 #define current_thread_info()  (current_thread_info_reg)
+#else
+extern struct thread_info *current_thread_info(void);
+#endif
 
 /* thread information allocation */
 #if PAGE_SHIFT == 13

diff --git a/arch/sparc/vdso/Makefile b/arch/sparc/vdso/Makefile
index a9e3a4f..a6e18ca 100644 (file)
--- a/arch/sparc/vdso/Makefile
+++ b/arch/sparc/vdso/Makefile
@@ -111,7 +111,8 @@ $(obj)/vdso32.so.dbg: FORCE \
 quiet_cmd_vdso = VDSO    $@
       cmd_vdso = $(LD) -nostdlib -o $@ \
                       $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
-                      -T $(filter %.lds,$^) $(filter %.o,$^)
+                      -T $(filter %.lds,$^) $(filter %.o,$^) && \
+               sh $(srctree)/$(src)/checkundef.sh '$(OBJDUMP)' '$@'
 
 VDSO_LDFLAGS = -shared $(call ld-option, --hash-style=both) \
        $(call ld-option, --build-id) -Bsymbolic

diff --git a/arch/sparc/vdso/checkundef.sh b/arch/sparc/vdso/checkundef.sh
new file mode 100644 (file)
index 0000000..2d85876
--- /dev/null
+++ b/arch/sparc/vdso/checkundef.sh
@@ -0,0 +1,10 @@
+#!/bin/sh
+objdump="$1"
+file="$2"
+$objdump -t "$file" | grep '*UUND*' | grep -v '#scratch' > /dev/null 2>&1
+if [ $? -eq 1 ]; then
+    exit 0
+else
+    echo "$file: undefined symbols found" >&2
+    exit 1
+fi