From c75c017e4c22bf8e5082a0cec1d8e9df76bac9dc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20Miros=C5=82aw?= <emmir@google.com>
Date: Fri, 2 Jun 2023 19:01:29 +0200
Subject: [PATCH] zdtm: thp_disable: Verify MADV_NOHUGEPAGE before migration
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Add a sanity check for THP_DISABLE. This discovered a broken commit
in Google's kernel tree.

Signed-off-by: Michał Mirosław <emmir@google.com>
---
 test/zdtm/static/thp_disable.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/test/zdtm/static/thp_disable.c b/test/zdtm/static/thp_disable.c
index e38508778..eabb45650 100644
--- a/test/zdtm/static/thp_disable.c
+++ b/test/zdtm/static/thp_disable.c
@@ -47,6 +47,21 @@ int main(int argc, char **argv)
 		return -1;
 	}
 
+	test_msg("Fetch pre-migration flags/adv\n");
+	if (get_smaps_bits((unsigned long)area, &new_flags, &new_madv))
+		return -1;
+
+	errno = 0;
+	if (orig_flags != new_flags) {
+		fail("Flags changed %lx -> %lx\n", orig_flags, new_flags);
+		return -1;
+	}
+
+	if (orig_madv != new_madv) {
+		fail("Madvs changed %lx -> %lx\n", orig_madv, new_madv);
+		return -1;
+	}
+
 	test_daemon();
 	test_waitsig();