userfaultfd: wp: add UFFDIO_COPY_MODE_WP

This allows UFFDIO_COPY to map pages write-protected.

[peterx@redhat.com: switch to VM_WARN_ON_ONCE in mfill_atomic_pte; add brackets
 around "dst_vma->vm_flags & VM_WRITE"; fix wordings in comments and
 commit messages]
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Bobby Powers <bobbypowers@gmail.com>
Cc: Brian Geffon <bgeffon@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Denis Plotnikov <dplotnikov@virtuozzo.com>
Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Kirill A . Shutemov" <kirill@shutemov.name>
Cc: Martin Cracauer <cracauer@cons.org>
Cc: Marty McFadden <mcfadden8@llnl.gov>
Cc: Maya Gokhale <gokhale2@llnl.gov>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Shaohua Li <shli@fb.com>
Link: http://lkml.kernel.org/r/20200220163112.11409-6-peterx@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Andrea Arcangeli 2020-04-06 20:05:41 -07:00 committed by Linus Torvalds
parent 55adf4de30
commit 72981e0e7b
4 changed files with 36 additions and 20 deletions

View file

@ -203,13 +203,14 @@ struct uffdio_copy {
__u64 dst;
__u64 src;
__u64 len;
/*
* There will be a wrprotection flag later that allows to map
* pages wrprotected on the fly. And such a flag will be
* available if the wrprotection ioctl are implemented for the
* range according to the uffdio_register.ioctls.
*/
#define UFFDIO_COPY_MODE_DONTWAKE ((__u64)1<<0)
/*
* UFFDIO_COPY_MODE_WP will map the page write protected on
* the fly. UFFDIO_COPY_MODE_WP is available only if the
* write protected ioctl is implemented for the range
* according to the uffdio_register.ioctls.
*/
#define UFFDIO_COPY_MODE_WP ((__u64)1<<1)
__u64 mode;
/*