From d312cb1e4884c606bafe6499fade2f91ccc2e944 Mon Sep 17 00:00:00 2001
From: Andrea Arcangeli <aarcange@redhat.com>
Date: Wed, 6 Sep 2017 16:23:49 -0700
Subject: [PATCH] userfaultfd: selftest: explicit failure if the SIGBUS test
 failed

Showing zero in the output isn't very self explanatory as a successful
result.  Show a more explicit error output if the test fails.

Link: http://lkml.kernel.org/r/20170802165145.22628-4-aarcange@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Alexey Perevalov <a.perevalov@samsung.com>
Cc: Maxime Coquelin <maxime.coquelin@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 tools/testing/selftests/vm/userfaultfd.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c
index 4549ae425f3e..a2c53a3d223d 100644
--- a/tools/testing/selftests/vm/userfaultfd.c
+++ b/tools/testing/selftests/vm/userfaultfd.c
@@ -987,7 +987,9 @@ static int userfaultfd_sig_test(void)
 		return 1;
 
 	printf("done.\n");
-	printf(" Signal test userfaults: %ld\n", userfaults);
+	if (userfaults)
+		fprintf(stderr, "Signal test failed, userfaults: %ld\n",
+			userfaults);
 	close(uffd);
 	return userfaults != 0;
 }