From afccb0804fc74ac2f6737af6a139632606cb461d Mon Sep 17 00:00:00 2001 From: Ryan Roberts Date: Tue, 14 Nov 2023 15:49:45 +0000 Subject: mm: more ptep_get() conversion Commit c33c794828f2 ("mm: ptep_get() conversion") converted all (non-arch) call sites to use ptep_get() instead of doing a direct dereference of the pte. Full rationale can be found in that commit's log. Since then, three new call sites have snuck in, which directly dereference the pte, so let's fix those up. Unfortunately there is no reliable automated mechanism to catch these; I'm relying on a combination of Coccinelle (which throws up a lot of false positives) and some compiler magic to force a compiler error on dereference (While this approach finds dereferences, it also yields a non-booting kernel so can't be committed). Link: https://lkml.kernel.org/r/20231114154945.490401-1-ryan.roberts@arm.com Signed-off-by: Ryan Roberts Cc: Matthew Wilcox (Oracle) Signed-off-by: Andrew Morton --- mm/userfaultfd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm/userfaultfd.c') diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c index 96d9eae5c7cc..0b6ca553bebe 100644 --- a/mm/userfaultfd.c +++ b/mm/userfaultfd.c @@ -312,7 +312,7 @@ static int mfill_atomic_pte_poison(pmd_t *dst_pmd, ret = -EEXIST; /* Refuse to overwrite any PTE, even a PTE marker (e.g. UFFD WP). */ - if (!pte_none(*dst_pte)) + if (!pte_none(ptep_get(dst_pte))) goto out_unlock; set_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte); -- cgit v1.2.3