[merged] mm-clear-vmf-pte-after-pte_unmap_same-returns.patch removed from -mm tree

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The patch titled
     Subject: mm: clear vmf->pte after pte_unmap_same() returns
has been removed from the -mm tree.  Its filename was
     mm-clear-vmf-pte-after-pte_unmap_same-returns.patch

This patch was dropped because it was merged into mainline or a subsystem tree

------------------------------------------------------
From: Peter Xu <peterx@xxxxxxxxxx>
Subject: mm: clear vmf->pte after pte_unmap_same() returns

pte_unmap_same() will always unmap the pte pointer.  After the unmap,
vmf->pte will not be valid any more, we should clear it.

It was safe only because no one is accessing vmf->pte after
pte_unmap_same() returns, since the only caller of pte_unmap_same() (so
far) is do_swap_page(), where vmf->pte will in most cases be overwritten
very soon.

Directly pass in vmf into pte_unmap_same() and then we can also avoid the
long parameter list too, which should be a nice cleanup.

Link: https://lkml.kernel.org/r/20210915181533.11188-1-peterx@xxxxxxxxxx
Signed-off-by: Peter Xu <peterx@xxxxxxxxxx>
Reviewed-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Reviewed-by: Liam Howlett <liam.howlett@xxxxxxxxxx>
Acked-by: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Alistair Popple <apopple@xxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Axel Rasmussen <axelrasmussen@xxxxxxxxxx>
Cc: Jerome Glisse <jglisse@xxxxxxxxxx>
Cc: "Kirill A . Shutemov" <kirill@xxxxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>
Cc: Yang Shi <shy828301@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 mm/memory.c |   12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

--- a/mm/memory.c~mm-clear-vmf-pte-after-pte_unmap_same-returns
+++ a/mm/memory.c
@@ -2728,19 +2728,19 @@ EXPORT_SYMBOL_GPL(apply_to_existing_page
  * proceeding (but do_wp_page is only called after already making such a check;
  * and do_anonymous_page can safely check later on).
  */
-static inline int pte_unmap_same(struct mm_struct *mm, pmd_t *pmd,
-				pte_t *page_table, pte_t orig_pte)
+static inline int pte_unmap_same(struct vm_fault *vmf)
 {
 	int same = 1;
 #if defined(CONFIG_SMP) || defined(CONFIG_PREEMPTION)
 	if (sizeof(pte_t) > sizeof(unsigned long)) {
-		spinlock_t *ptl = pte_lockptr(mm, pmd);
+		spinlock_t *ptl = pte_lockptr(vmf->vma->vm_mm, vmf->pmd);
 		spin_lock(ptl);
-		same = pte_same(*page_table, orig_pte);
+		same = pte_same(*vmf->pte, vmf->orig_pte);
 		spin_unlock(ptl);
 	}
 #endif
-	pte_unmap(page_table);
+	pte_unmap(vmf->pte);
+	vmf->pte = NULL;
 	return same;
 }
 
@@ -3492,7 +3492,7 @@ vm_fault_t do_swap_page(struct vm_fault
 	vm_fault_t ret = 0;
 	void *shadow = NULL;
 
-	if (!pte_unmap_same(vma->vm_mm, vmf->pmd, vmf->pte, vmf->orig_pte))
+	if (!pte_unmap_same(vmf))
 		goto out;
 
 	entry = pte_to_swp_entry(vmf->orig_pte);
_

Patches currently in -mm which might be from peterx@xxxxxxxxxx are





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