diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 635f0f0f6860..78f5df12b8eb 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2260,12 +2260,14 @@ void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, { spinlock_t *ptl; struct mmu_notifier_range range; + bool pmd_migration; mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma->vm_mm, address & HPAGE_PMD_MASK, (address & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE); mmu_notifier_invalidate_range_start(&range); ptl = pmd_lock(vma->vm_mm, pmd); + pmd_migration = is_pmd_migration_entry(*pmd); /* * If caller asks to setup a migration entry, we need a folio to check @@ -2274,13 +2276,12 @@ void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, VM_BUG_ON(freeze && !folio); VM_WARN_ON_ONCE(folio && !folio_test_locked(folio)); - if (pmd_trans_huge(*pmd) || pmd_devmap(*pmd) || - is_pmd_migration_entry(*pmd)) { + if (pmd_trans_huge(*pmd) || pmd_devmap(*pmd) || pmd_migration) { /* - * It's safe to call pmd_page when folio is set because it's - * guaranteed that pmd is present. + * Do not apply pmd_folio() to a migration entry; and folio lock + * guarantees that it must be of the wrong folio anyway. */ - if (folio && folio != page_folio(pmd_page(*pmd))) + if (folio && (pmd_migration || folio != page_folio(pmd_page(*pmd)))) goto out; __split_huge_pmd_locked(vma, pmd, range.start, freeze); }