diff mbox series

[03/12] arm: adjust_pte() use pte_offset_map_nolock()

Message ID 94c2ebe1-6b23-1cee-4aae-22cb835776ff@google.com (mailing list archive)
State New
Headers show
Series mm: free retracted page table by RCU | expand

Commit Message

Hugh Dickins May 29, 2023, 6:17 a.m. UTC 
Instead of pte_lockptr(), use the recently added pte_offset_map_nolock()
in adjust_pte(): because it gives the not-locked ptl for precisely that
pte, which the caller can then safely lock; whereas pte_lockptr() is not
so tightly coupled, because it dereferences the pmd pointer again.

Signed-off-by: Hugh Dickins <hughd@google.com>
---
 arch/arm/mm/fault-armv.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/arch/arm/mm/fault-armv.c b/arch/arm/mm/fault-armv.c
index ca5302b0b7ee..7cb125497976 100644
--- a/arch/arm/mm/fault-armv.c
+++ b/arch/arm/mm/fault-armv.c
@@ -117,11 +117,10 @@  static int adjust_pte(struct vm_area_struct *vma, unsigned long address,
 	 * must use the nested version.  This also means we need to
 	 * open-code the spin-locking.
 	 */
-	pte = pte_offset_map(pmd, address);
+	pte = pte_offset_map_nolock(vma->vm_mm, pmd, address, &ptl);
 	if (!pte)
 		return 0;
 
-	ptl = pte_lockptr(vma->vm_mm, pmd);
 	do_pte_lock(ptl);
 
 	ret = do_adjust_pte(vma, address, pfn, pte);