include/linux/mm.h |  5 +++--
 mm/nommu.c         | 11 +++++++++++
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 39aa409e84d5..4f2c33c273eb 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2323,6 +2323,9 @@ void pagecache_isize_extended(struct inode *inode, loff_t from, loff_t to);
 void truncate_pagecache_range(struct inode *inode, loff_t offset, loff_t end);
 int generic_error_remove_page(struct address_space *mapping, struct page *page);
 
+struct vm_area_struct *lock_mm_and_find_vma(struct mm_struct *mm,
+		unsigned long address, struct pt_regs *regs);
+
 #ifdef CONFIG_MMU
 extern vm_fault_t handle_mm_fault(struct vm_area_struct *vma,
 				  unsigned long address, unsigned int flags,
@@ -2334,8 +2337,6 @@ void unmap_mapping_pages(struct address_space *mapping,
 		pgoff_t start, pgoff_t nr, bool even_cows);
 void unmap_mapping_range(struct address_space *mapping,
 		loff_t const holebegin, loff_t const holelen, int even_cows);
-struct vm_area_struct *lock_mm_and_find_vma(struct mm_struct *mm,
-		unsigned long address, struct pt_regs *regs);
 #else
 static inline vm_fault_t handle_mm_fault(struct vm_area_struct *vma,
 					 unsigned long address, unsigned int flags,
diff --git a/mm/nommu.c b/mm/nommu.c
index 37d0b03143f1..fdc392735ec6 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -630,6 +630,17 @@ struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr)
 }
 EXPORT_SYMBOL(find_vma);
 
+/*
+ * At least xtensa ends up having protection faults even with no
+ * MMU.. No stack expansion, at least.
+ */
+struct vm_area_struct *lock_mm_and_find_vma(struct mm_struct *mm,
+			unsigned long addr, struct pt_regs *regs)
+{
+	mmap_read_lock(mm);
+	return vma_lookup(mm, addr);
+}
+
 /*
  * expand a stack to a given address
  * - not supported under NOMMU conditions