[PATCH 2/2] kselftest/vm: fix tests build with old libc

[Chengming Zhou <zhouchengming@bytedance.com>]

The error message when I build vm tests on debian10 (GLIBC 2.28):

userfaultfd.c: In function ‘userfaultfd_pagemap_test’:
userfaultfd.c:1393:37: error: ‘MADV_PAGEOUT’ undeclared (first use
in this function); did you mean ‘MADV_RANDOM’?
  if (madvise(area_dst, test_pgsize, MADV_PAGEOUT))
                                     ^~~~~~~~~~~~
                                     MADV_RANDOM

This patch includes these newer definitions from UAPI linux/mman.h,
is useful to fix tests build on systems without these definitions in
glibc sys/mman.h.

Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
---
 tools/testing/selftests/vm/userfaultfd.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c
index 2f49c9af1b58..3fc1d2ee2948 100644
--- a/tools/testing/selftests/vm/userfaultfd.c
+++ b/tools/testing/selftests/vm/userfaultfd.c
@@ -46,6 +46,7 @@
 #include <signal.h>
 #include <poll.h>
 #include <string.h>
+#include <linux/mman.h>
 #include <sys/mman.h>
 #include <sys/syscall.h>
 #include <sys/ioctl.h>
-- 
2.20.1