[PATCH RFC 2/4] mm: Check against orig_pte for finish_fault()

[Peter Xu]

We used to check against none pte and in those cases orig_pte should always be
none pte anyway.

This change prepares us to be able to call do_fault() on !none ptes.  For
example, we should allow that to happen for pte marker that has PAGEOUT set.

Signed-off-by: Peter Xu <peterx@xxxxxxxxxx>
---
 mm/memory.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/memory.c b/mm/memory.c
index 25fc46e87214..7288f585544a 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -4047,7 +4047,7 @@ vm_fault_t finish_fault(struct vm_fault *vmf)
 				      vmf->address, &vmf->ptl);
 	ret = 0;
 	/* Re-check under ptl */
-	if (likely(pte_none(*vmf->pte)))
+	if (likely(pte_same(*vmf->pte, vmf->orig_pte)))
 		do_set_pte(vmf, page, vmf->address);
 	else
 		ret = VM_FAULT_NOPAGE;
-- 
2.32.0