[PATCH v3 2/5] selftests/mm: run_vmtests: remove sudo and conform to tap

[Muhammad Usama Anjum <usama.anjum@collabora.com>]

Remove sudo as some test running environments may not have sudo
available. Instead skip the test if root privileges aren't available in
the test.

Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
---
Changes since v1:
- Added this patch in v2

We are allocating 2*RLIMIT_MEMLOCK.rlim_max memory and mmap() isn't
failing. This seems like true bug in the kernel. Even the root user
shouldn't be able to allocate more memory than allowed MEMLOCKed memory.
Any ideas?
---
 tools/testing/selftests/mm/on-fault-limit.c | 36 ++++++++++-----------
 tools/testing/selftests/mm/run_vmtests.sh   |  2 +-
 2 files changed, 18 insertions(+), 20 deletions(-)

diff --git a/tools/testing/selftests/mm/on-fault-limit.c b/tools/testing/selftests/mm/on-fault-limit.c
index b5888d613f34e..0ea98ffab3589 100644
--- a/tools/testing/selftests/mm/on-fault-limit.c
+++ b/tools/testing/selftests/mm/on-fault-limit.c
@@ -5,40 +5,38 @@
 #include <string.h>
 #include <sys/time.h>
 #include <sys/resource.h>
+#include "../kselftest.h"
 
-static int test_limit(void)
+static void test_limit(void)
 {
-	int ret = 1;
 	struct rlimit lims;
 	void *map;
 
-	if (getrlimit(RLIMIT_MEMLOCK, &lims)) {
-		perror("getrlimit");
-		return ret;
-	}
+	if (getrlimit(RLIMIT_MEMLOCK, &lims))
+		ksft_exit_fail_msg("getrlimit: %s\n", strerror(errno));
 
-	if (mlockall(MCL_ONFAULT | MCL_FUTURE)) {
-		perror("mlockall");
-		return ret;
-	}
+	if (mlockall(MCL_ONFAULT | MCL_FUTURE))
+		ksft_exit_fail_msg("mlockall: %s\n", strerror(errno));
 
 	map = mmap(NULL, 2 * lims.rlim_max, PROT_READ | PROT_WRITE,
 		   MAP_PRIVATE | MAP_ANONYMOUS | MAP_POPULATE, -1, 0);
+
+	ksft_test_result(map == MAP_FAILED, "Failed mmap\n");
+
 	if (map != MAP_FAILED)
-		printf("mmap should have failed, but didn't\n");
-	else {
-		ret = 0;
 		munmap(map, 2 * lims.rlim_max);
-	}
-
 	munlockall();
-	return ret;
 }
 
 int main(int argc, char **argv)
 {
-	int ret = 0;
+	ksft_print_header();
+	ksft_set_plan(1);
+
+	if (getuid())
+		ksft_test_result_skip("Require root privileges to run\n");
+	else
+		test_limit();
 
-	ret += test_limit();
-	return ret;
+	ksft_finished();
 }
diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh
index 246d53a5d7f28..e373d592dbf5c 100755
--- a/tools/testing/selftests/mm/run_vmtests.sh
+++ b/tools/testing/selftests/mm/run_vmtests.sh
@@ -291,7 +291,7 @@ echo "$nr_hugepgs" > /proc/sys/vm/nr_hugepages
 
 CATEGORY="compaction" run_test ./compaction_test
 
-CATEGORY="mlock" run_test sudo -u nobody ./on-fault-limit
+CATEGORY="mlock" run_test ./on-fault-limit
 
 CATEGORY="mmap" run_test ./map_populate
 
-- 
2.42.0