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authorPeter Xu <peterx@redhat.com>2022-05-12 20:22:54 -0700
committerAndrew Morton <akpm@linux-foundation.org>2022-05-13 07:20:11 -0700
commit5a90d5a103c2badfcf12d48e2fec350969e3f486 (patch)
tree86e472727415249843f8f422011d859bedbe95fd /mm/userfaultfd.c
parent6041c69179034278ac6d57f90a55b09e588f4b90 (diff)
mm/hugetlb: handle UFFDIO_WRITEPROTECT
This starts from passing cp_flags into hugetlb_change_protection() so hugetlb will be able to handle MM_CP_UFFD_WP[_RESOLVE] requests. huge_pte_clear_uffd_wp() is introduced to handle the case where the UFFDIO_WRITEPROTECT is requested upon migrating huge page entries. Link: https://lkml.kernel.org/r/20220405014906.14708-1-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: "Kirill A . Shutemov" <kirill@shutemov.name> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/userfaultfd.c')
-rw-r--r--mm/userfaultfd.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index be2a61f4b55e..01edc18902c5 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -705,6 +705,7 @@ int mwriteprotect_range(struct mm_struct *dst_mm, unsigned long start,
atomic_t *mmap_changing)
{
struct vm_area_struct *dst_vma;
+ unsigned long page_mask;
struct mmu_gather tlb;
pgprot_t newprot;
int err;
@@ -742,6 +743,13 @@ int mwriteprotect_range(struct mm_struct *dst_mm, unsigned long start,
if (!vma_is_anonymous(dst_vma))
goto out_unlock;
+ if (is_vm_hugetlb_page(dst_vma)) {
+ err = -EINVAL;
+ page_mask = vma_kernel_pagesize(dst_vma) - 1;
+ if ((start & page_mask) || (len & page_mask))
+ goto out_unlock;
+ }
+
if (enable_wp)
newprot = vm_get_page_prot(dst_vma->vm_flags & ~(VM_WRITE));
else