From 05ce77249d5068b057082d24ec22d3824f4816ac Mon Sep 17 00:00:00 2001
From: Pavel Emelyanov <xemul@parallels.com>
Date: Wed, 22 Feb 2017 15:42:40 -0800
Subject: userfaultfd: non-cooperative: add madvise() event for MADV_DONTNEED
 request

If the page is punched out of the address space the uffd reader should
know this and zeromap the respective area in case of the #PF event.

Link: http://lkml.kernel.org/r/20161216144821.5183-14-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>
---
 mm/madvise.c | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'mm/madvise.c')

diff --git a/mm/madvise.c b/mm/madvise.c
index 0e3828eae9f8..06ffb5a170de 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -10,6 +10,7 @@
 #include <linux/syscalls.h>
 #include <linux/mempolicy.h>
 #include <linux/page-isolation.h>
+#include <linux/userfaultfd_k.h>
 #include <linux/hugetlb.h>
 #include <linux/falloc.h>
 #include <linux/sched.h>
@@ -477,6 +478,7 @@ static long madvise_dontneed(struct vm_area_struct *vma,
 		return -EINVAL;
 
 	zap_page_range(vma, start, end - start, NULL);
+	madvise_userfault_dontneed(vma, prev, start, end);
 	return 0;
 }
 
-- 
cgit v1.2.3