diff options
| -rw-r--r-- | mm/userfaultfd.c | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c index f8d31b82aceb..46771362550f 100644 --- a/mm/userfaultfd.c +++ b/mm/userfaultfd.c @@ -713,17 +713,25 @@ ssize_t mcopy_continue(struct mm_struct *dst_mm, unsigned long start, void uffd_wp_range(struct mm_struct *dst_mm, struct vm_area_struct *dst_vma, unsigned long start, unsigned long len, bool enable_wp) { + unsigned int mm_cp_flags; struct mmu_gather tlb; - pgprot_t newprot; if (enable_wp) - newprot = vm_get_page_prot(dst_vma->vm_flags & ~(VM_WRITE)); + mm_cp_flags = MM_CP_UFFD_WP; else - newprot = vm_get_page_prot(dst_vma->vm_flags); + mm_cp_flags = MM_CP_UFFD_WP_RESOLVE; + /* + * vma->vm_page_prot already reflects that uffd-wp is enabled for this + * VMA (see userfaultfd_set_vm_flags()) and that all PTEs are supposed + * to be write-protected as default whenever protection changes. + * Try upgrading write permissions manually. + */ + if (!enable_wp && vma_wants_manual_pte_write_upgrade(dst_vma)) + mm_cp_flags |= MM_CP_TRY_CHANGE_WRITABLE; tlb_gather_mmu(&tlb, dst_mm); - change_protection(&tlb, dst_vma, start, start + len, newprot, - enable_wp ? MM_CP_UFFD_WP : MM_CP_UFFD_WP_RESOLVE); + change_protection(&tlb, dst_vma, start, start + len, vma->vm_page_prot, + mm_cp_flags); tlb_finish_mmu(&tlb); } |