From: James Houghton jthoughton@google.com
commit 63cf584203f3367c8b073d417c8e5cbbfc450506 upstream.
By checking huge_pte_none(), we incorrectly classify PTE markers as "present". Instead, check huge_pte_none_mostly(), classifying PTE markers the same as if the PTE were completely blank.
PTE markers, unlike other kinds of swap entries, don't reference any physical page and don't indicate that a physical page was mapped previously. As such, treat them as non-present for the sake of mincore().
Link: https://lkml.kernel.org/r/20230302222404.175303-1-jthoughton@google.com Fixes: 5c041f5d1f23 ("mm: teach core mm about pte markers") Signed-off-by: James Houghton jthoughton@google.com Acked-by: Peter Xu peterx@redhat.com Acked-by: David Hildenbrand david@redhat.com Cc: Axel Rasmussen axelrasmussen@google.com Cc: James Houghton jthoughton@google.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- mm/mincore.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/mincore.c b/mm/mincore.c index cd69b9db0081..d359650b0f75 100644 --- a/mm/mincore.c +++ b/mm/mincore.c @@ -33,7 +33,7 @@ static int mincore_hugetlb(pte_t *pte, unsigned long hmask, unsigned long addr, * Hugepages under user process are always in RAM and never * swapped out, but theoretically it needs to be checked. */ - present = pte && !huge_pte_none(huge_ptep_get(pte)); + present = pte && !huge_pte_none_mostly(huge_ptep_get(pte)); for (; addr != end; vec++, addr += PAGE_SIZE) *vec = present; walk->private = vec;