mm: export find_extend_vma() and handle_mm_fault() for driver use

This lets drivers like the AMD IOMMUv2 driver handle faults a bit more
simply, rather than doing tricks with page refs and get_user_pages().
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Cc: Oded Gabbay <oded.gabbay@amd.com>
Cc: Joerg Roedel <jroedel@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mm/memory.c

@@ -3365,6 +3365,7 @@ int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 
 	return ret;
 }
+EXPORT_SYMBOL_GPL(handle_mm_fault);
 
 #ifndef __PAGETABLE_PUD_FOLDED
 /*

mm/mmap.c

@@ -2362,6 +2362,8 @@ find_extend_vma(struct mm_struct *mm, unsigned long addr)
 }
 #endif
 
+EXPORT_SYMBOL_GPL(find_extend_vma);
+
 /*
  * Ok - we have the memory areas we should free on the vma list,
  * so release them, and do the vma updates.