diff options
Diffstat (limited to 'mm/hugetlb.c')
| -rw-r--r-- | mm/hugetlb.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 8bfd07f4c143..a58b3739ed4b 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -5478,7 +5478,7 @@ static vm_fault_t hugetlb_wp(struct mm_struct *mm, struct vm_area_struct *vma, struct folio *pagecache_folio, spinlock_t *ptl) { const bool unshare = flags & FAULT_FLAG_UNSHARE; - pte_t pte; + pte_t pte = huge_ptep_get(ptep); struct hstate *h = hstate_vma(vma); struct page *old_page; struct folio *new_folio; @@ -5488,6 +5488,17 @@ static vm_fault_t hugetlb_wp(struct mm_struct *mm, struct vm_area_struct *vma, struct mmu_notifier_range range; /* + * Never handle CoW for uffd-wp protected pages. It should be only + * handled when the uffd-wp protection is removed. + * + * Note that only the CoW optimization path (in hugetlb_no_page()) + * can trigger this, because hugetlb_fault() will always resolve + * uffd-wp bit first. + */ + if (!unshare && huge_pte_uffd_wp(pte)) + return 0; + + /* * hugetlb does not support FOLL_FORCE-style write faults that keep the * PTE mapped R/O such as maybe_mkwrite() would do. */ @@ -5500,7 +5511,6 @@ static vm_fault_t hugetlb_wp(struct mm_struct *mm, struct vm_area_struct *vma, return 0; } - pte = huge_ptep_get(ptep); old_page = pte_page(pte); delayacct_wpcopy_start(); |