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>
diff --git a/mm/madvise.c b/mm/madvise.c
index 0e3828ea..06ffb5a 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 @@
return -EINVAL;
zap_page_range(vma, start, end - start, NULL);
+ madvise_userfault_dontneed(vma, prev, start, end);
return 0;
}