From e9295ad15a9e3e9eb314f6c486a836ee3ee17cc5 Mon Sep 17 00:00:00 2001 From: James Houghton Date: Thu, 2 Mar 2023 22:24:04 +0000 Subject: [PATCH] mm: teach mincore_hugetlb about pte markers commit c9d46e101a079d41582aaa8727b74a0f6e273a9b 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: f8a324dbfb0b ("mm: teach core mm about pte markers") Signed-off-by: James Houghton Acked-by: Peter Xu Acked-by: David Hildenbrand Cc: Axel Rasmussen Cc: James Houghton Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- mm/mincore.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/mincore.c b/mm/mincore.c index fa200c14185fc..1eb6aac88d845 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; -- 2.39.5