ioctl_userfaultfd.2: Add UFFD_FEATURE_THREAD_ID docs

UFFD_FEATURE_THREAD_ID is supported in Linux 4.14.

Acked-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

diff --git a/man2/ioctl_userfaultfd.2 b/man2/ioctl_userfaultfd.2
index 9120bdf40ef2dadd033f4d6065e4a61512ead7c6..014c0b5c104816670258cd7e2d6eada36675c8d1 100644 (file)
--- a/man2/ioctl_userfaultfd.2
+++ b/man2/ioctl_userfaultfd.2
@@ -208,6 +208,11 @@ signal will be sent to the faulting process.
 Applications using this
 feature will not require the use of a userfaultfd monitor for processing
 memory accesses to the regions registered with userfaultfd.
+.TP
+.BR UFFD_FEATURE_THREAD_ID " (since Linux 4.14)"
+If this feature bit is set,
+.I uffd_msg.pagefault.feat.ptid
+will be set to the faulted thread ID for each page fault message.
 .PP
 The returned
 .I ioctls