]> git.baikalelectronics.ru Git - kernel.git/commit
userfaultfd: report actual registered features in fdinfo
authorMike Rapoport <rppt@linux.vnet.ibm.com>
Fri, 7 Apr 2017 23:04:42 +0000 (16:04 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Sat, 8 Apr 2017 07:47:48 +0000 (00:47 -0700)
commitd5ac54a71c8603fa7d731a274e2ecafe9a4906da
tree8495ab4992f0a50304649c67016b2b965b515db6
parentad1b4f0c48262dd432086f0c8cee06996fc6d182
userfaultfd: report actual registered features in fdinfo

fdinfo for userfault file descriptor reports UFFD_API_FEATURES.  Up
until recently, the UFFD_API_FEATURES was defined as 0, therefore
corresponding field in fdinfo always contained zero.  Now, with
introduction of several additional features, UFFD_API_FEATURES is not
longer 0 and it seems better to report actual features requested for the
userfaultfd object described by the fdinfo.

First, the applications that were using userfault will still see zero at
the features field in fdinfo.  Next, reporting actual features rather
than available features, gives clear indication of what userfault
features are used by an application.

Link: http://lkml.kernel.org/r/1491140181-22121-1-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/userfaultfd.c