diff options
Diffstat (limited to 'mm/userfaultfd.c')
-rw-r--r-- | mm/userfaultfd.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c index 4744d6a96f96..a0331ba9ae2a 100644 --- a/mm/userfaultfd.c +++ b/mm/userfaultfd.c @@ -845,6 +845,15 @@ ssize_t mfill_atomic_zeropage(struct userfaultfd_ctx *ctx, ssize_t mfill_atomic_continue(struct userfaultfd_ctx *ctx, unsigned long start, unsigned long len, uffd_flags_t flags) { + + /* + * A caller might reasonably assume that UFFDIO_CONTINUE contains an + * smp_wmb() to ensure that any writes to the about-to-be-mapped page by + * the thread doing the UFFDIO_CONTINUE are guaranteed to be visible to + * subsequent loads from the page through the newly mapped address range. + */ + smp_wmb(); + return mfill_atomic(ctx, start, 0, len, uffd_flags_set_mode(flags, MFILL_ATOMIC_CONTINUE)); } |