[PATCH] ppc64: lacks definition of MM_VM_SIZE()

With David Woodhouse <dwmw2@infradead.org>

We don't set MM_VM_SIZE() on ppc64, so it defaults to TASK_SIZE.  Which
means a 32-bit process ending up in exit_mmap() to kill a 64-bit mm may
call tlb_finish_mmu() with an incorrect 'end' argument.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

include/asm-ppc64/processor.h

@@ -537,6 +537,10 @@ extern struct task_struct *last_task_used_altivec;
 #define TASK_SIZE (test_thread_flag(TIF_32BIT) ? \
 		TASK_SIZE_USER32 : TASK_SIZE_USER64)
 
+/* We can't actually tell the TASK_SIZE given just the mm, but default
+ * to the 64-bit case to make sure that enough gets cleaned up. */
+#define MM_VM_SIZE(mm)	TASK_SIZE_USER64
+
 /* This decides where the kernel will search for a free chunk of vm
  * space during mmap's.
  */