diff options
| author | Peter Xu <peterx@redhat.com> | 2022-05-12 20:22:54 -0700 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2022-05-13 07:20:10 -0700 |
| commit | 6041c69179034278ac6d57f90a55b09e588f4b90 (patch) | |
| tree | c6b44728f128b4435e9db1e509104eec78bff73a /mm/userfaultfd.c | |
| parent | 166f3ecc0daf0c164bd7e2f780dbcd1e213ac95f (diff) | |
mm/hugetlb: take care of UFFDIO_COPY_MODE_WP
Pass the wp_copy variable into hugetlb_mcopy_atomic_pte() thoughout the
stack. Apply the UFFD_WP bit if UFFDIO_COPY_MODE_WP is with UFFDIO_COPY.
Hugetlb pages are only managed by hugetlbfs, so we're safe even without
setting dirty bit in the huge pte if the page is installed as read-only.
However we'd better still keep the dirty bit set for a read-only
UFFDIO_COPY pte (when UFFDIO_COPY_MODE_WP bit is set), not only to match
what we do with shmem, but also because the page does contain dirty data
that the kernel just copied from the userspace.
Link: https://lkml.kernel.org/r/20220405014904.14643-1-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.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 Kravetz <mike.kravetz@oracle.com>
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.c | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c index 2b6ec3352147..be2a61f4b55e 100644 --- a/mm/userfaultfd.c +++ b/mm/userfaultfd.c @@ -305,7 +305,8 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm, unsigned long dst_start, unsigned long src_start, unsigned long len, - enum mcopy_atomic_mode mode) + enum mcopy_atomic_mode mode, + bool wp_copy) { int vm_shared = dst_vma->vm_flags & VM_SHARED; ssize_t err; @@ -393,7 +394,7 @@ retry: } if (mode != MCOPY_ATOMIC_CONTINUE && - !huge_pte_none(huge_ptep_get(dst_pte))) { + !huge_pte_none_mostly(huge_ptep_get(dst_pte))) { err = -EEXIST; mutex_unlock(&hugetlb_fault_mutex_table[hash]); i_mmap_unlock_read(mapping); @@ -401,7 +402,8 @@ retry: } err = hugetlb_mcopy_atomic_pte(dst_mm, dst_pte, dst_vma, - dst_addr, src_addr, mode, &page); + dst_addr, src_addr, mode, &page, + wp_copy); mutex_unlock(&hugetlb_fault_mutex_table[hash]); i_mmap_unlock_read(mapping); @@ -456,7 +458,8 @@ extern ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm, unsigned long dst_start, unsigned long src_start, unsigned long len, - enum mcopy_atomic_mode mode); + enum mcopy_atomic_mode mode, + bool wp_copy); #endif /* CONFIG_HUGETLB_PAGE */ static __always_inline ssize_t mfill_atomic_pte(struct mm_struct *dst_mm, @@ -576,7 +579,8 @@ retry: */ if (is_vm_hugetlb_page(dst_vma)) return __mcopy_atomic_hugetlb(dst_mm, dst_vma, dst_start, - src_start, len, mcopy_mode); + src_start, len, mcopy_mode, + wp_copy); if (!vma_is_anonymous(dst_vma) && !vma_is_shmem(dst_vma)) goto out_unlock; |