userfaultfd: non-cooperative: add ability to report non-PF events from uffd descriptor
authorPavel Emelyanov <xemul@parallels.com>
Wed, 22 Feb 2017 23:42:21 +0000 (15:42 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 23 Feb 2017 00:41:28 +0000 (16:41 -0800)
commit9cd75c3cd4c3d06aa0c4ed8ef5327d811a8b6cff
treed1a58d5498d477fe285205b6b06587a820b76559
parent6dcc27fd39437f77057322cf314cc545bf0e4863
userfaultfd: non-cooperative: add ability to report non-PF events from uffd descriptor

The custom events are queued in ctx->event_wqh not to disturb the
fast-path-ed PF queue-wait-wakeup functions.

The events to be generated (other than PF-s) are requested in UFFD_API
ioctl with the uffd_api.features bits. Those, known by the kernel, are
then turned on and reported back to the user-space.

Link: http://lkml.kernel.org/r/20161216144821.5183-7-aarcange@redhat.com
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Michael Rapoport <RAPOPORT@il.ibm.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/userfaultfd.c