userfaultfd: hugetlbfs: fix __mcopy_atomic_hugetlb retry/error processing

The new routine copy_huge_page_from_user() uses kmap_atomic() to map
PAGE_SIZE pages.  However, this prevents page faults in the subsequent
call to copy_from_user().  This is OK in the case where the routine is
copied with mmap_sema held.  However, in another case we want to allow
page faults.  So, add a new argument allow_pagefault to indicate if the
routine should allow page faults.

[[email protected]: unmap the correct pointer]
  Link: http://lkml.kernel.org/r/20170113082608.GA3548@mwanda
[[email protected]: kunmap() takes a page*, per Hugh]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Mike Kravetz <[email protected]>
Signed-off-by: Andrea Arcangeli <[email protected]>
Signed-off-by: Dan Carpenter <[email protected]>
Cc: "Dr. David Alan Gilbert" <[email protected]>
Cc: Hillf Danton <[email protected]>
Cc: Michael Rapoport <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Pavel Emelyanov <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Hugh Dickins <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions