[PATCH v6 03/23] mm: Check against orig_pte for finish_fault()

From: Peter Xu
Date: Mon Nov 15 2021 - 02:57:01 EST


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 so that we can restore
information out of the pte markers.

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 04662b010005..d5966d9e24c3 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -4052,7 +4052,7 @@ 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