diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index eae16facc390eb694fbb1d950fd61c8b74473fab..ad36e8521577893c2a49d139996b31d2056461ff 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -413,6 +413,8 @@ extern int fix_alignment(struct pt_regs *);
 #define NET_IP_ALIGN	0
 #endif
 
+int do_mathemu(struct pt_regs *regs);
+
 #endif /* __KERNEL__ */
 #endif /* __ASSEMBLY__ */
 #endif /* _ASM_POWERPC_PROCESSOR_H */
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 286b3a6b5c5e242d46d087e4dca406f00ba5f129..76d17492e0e52dbcf649a41bc39c3a76103f3f41 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1405,7 +1405,6 @@ int is_valid_bugaddr(unsigned long addr)
 static int emulate_math(struct pt_regs *regs)
 {
 	int ret;
-	extern int do_mathemu(struct pt_regs *regs);
 
 	ret = do_mathemu(regs);
 	if (ret >= 0)
diff --git a/arch/powerpc/math-emu/math.c b/arch/powerpc/math-emu/math.c
index 30b4b69c694198dc557d5262d5dba7cd0308ec30..327165f26ca6a66f732e5ac2af0c59904054f1de 100644
--- a/arch/powerpc/math-emu/math.c
+++ b/arch/powerpc/math-emu/math.c
@@ -225,7 +225,7 @@ record_exception(struct pt_regs *regs, int eflag)
 int
 do_mathemu(struct pt_regs *regs)
 {
-	void *op0 = 0, *op1 = 0, *op2 = 0, *op3 = 0;
+	void *op0 = NULL, *op1 = NULL, *op2 = NULL, *op3 = NULL;
 	unsigned long pc = regs->nip;
 	signed short sdisp;
 	u32 insn = 0;
@@ -234,7 +234,7 @@ do_mathemu(struct pt_regs *regs)
 	int type = 0;
 	int eflag, trap;
 
-	if (get_user(insn, (u32 *)pc))
+	if (get_user(insn, (u32 __user *)pc))
 		return -EFAULT;
 
 	switch (insn >> 26) {