[08/15] mm: Export follow_pte()

Commit Message

Jan Kara July 22, 2016, 12:19 p.m. UTC

DAX will need to implement its own version of page_check_address(). To
avoid duplicating page table walking code, export follow_pte() which
does what we need.

Signed-off-by: Jan Kara <[e-mail]>
---
 include/linux/mm.h | 2 ++
 mm/memory.c        | 5 +++--
 2 files changed, 5 insertions(+), 2 deletions(-)

Patch

diff --git a/include/linux/mm.h b/include/linux/mm.h
index d2f2816d78ca..daf690fccc0c 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1191,6 +1191,8 @@  int copy_page_range(struct mm_struct *dst, struct mm_struct *src,
 			struct vm_area_struct *vma);
 void unmap_mapping_range(struct address_space *mapping,
 		loff_t const holebegin, loff_t const holelen, int even_cows);
+int follow_pte(struct mm_struct *mm, unsigned long address, pte_t **ptepp,
+	       spinlock_t **ptlp);
 int follow_pfn(struct vm_area_struct *vma, unsigned long address,
 	unsigned long *pfn);
 int follow_phys(struct vm_area_struct *vma, unsigned long address,
diff --git a/mm/memory.c b/mm/memory.c
index cfae2d5cc1e0..6780e5d8145c 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3635,8 +3635,8 @@  out:
 	return -EINVAL;
 }
 
-static inline int follow_pte(struct mm_struct *mm, unsigned long address,
-			     pte_t **ptepp, spinlock_t **ptlp)
+int follow_pte(struct mm_struct *mm, unsigned long address, pte_t **ptepp,
+	       spinlock_t **ptlp)
 {
 	int res;
 
@@ -3645,6 +3645,7 @@  static inline int follow_pte(struct mm_struct *mm, unsigned long address,
 			   !(res = __follow_pte(mm, address, ptepp, ptlp)));
 	return res;
 }
+EXPORT_SYMBOL(follow_pte);
 
 /**
  * follow_pfn - look up PFN at a user virtual address