From: Hugh Dickins <hughd@google.com> mainline inclusion from mainline-v6.7-rc1 commit b1454b463c217e5bc553acc44b2389d9257c9708 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I8YQMW Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- Since commit dc68badcede4 ("mm: mlock: update mlock_pte_range to handle large folio") I've just occasionally seen VM_WARN_ON_FOLIO(folio_test_ksm) warnings from folio_within_range(), in a splurge after testing with KSM hyperactive. folio_referenced_one()'s use of folio_within_vma() is safe because it checks folio_test_large() first; but allow_mlock_munlock() needs to do the same to avoid those warnings (or check !folio_test_ksm() itself? Or move either check into folio_within_range()? Hard to tell without more examples of its use). Link: https://lkml.kernel.org/r/23852f6a-5bfa-1ffd-30db-30c5560ad426@google.com Fixes: dc68badcede4 ("mm: mlock: update mlock_pte_range to handle large folio") Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: Yin Fengwei <fengwei.yin@intel.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Stefan Roesch <shr@devkernel.io> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: ZhangPeng <zhangpeng362@huawei.com> --- mm/mlock.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/mm/mlock.c b/mm/mlock.c index 42b6865f8f82..f79d8262c1a0 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -346,6 +346,10 @@ static inline bool allow_mlock_munlock(struct folio *folio, if (!(vma->vm_flags & VM_LOCKED)) return true; + /* folio_within_range() cannot take KSM, but any small folio is OK */ + if (!folio_test_large(folio)) + return true; + /* folio not in range [start, end), skip mlock */ if (!folio_within_range(folio, vma, start, end)) return false; -- 2.25.1