--- a/tools/testing/selftests/timers/posix_timers.c
+++ b/tools/testing/selftests/timers/posix_timers.c
@@ -10,6 +10,7 @@
 #include <sys/time.h>
 #include <stdio.h>
 #include <signal.h>
+#include <string.h>
 #include <unistd.h>
 #include <time.h>
 #include <pthread.h>
@@ -19,6 +20,20 @@
 #define DELAY 2
 #define USECS_PER_SEC 1000000
 
+static void __fatal_error(const char *test, const char *name, const char *what)
+{
+	char buf[64];
+
+	strerror_r(errno, buf, sizeof(buf));
+
+	if (name && strlen(name))
+		ksft_exit_fail_msg("%s %s %s %s\n", test, name, what, buf);
+	else
+		ksft_exit_fail_msg("%s %s %s\n", test, what, buf);
+}
+
+#define fatal_error(name, what)	__fatal_error(__func__, name, what)
+
 static volatile int done;
 
 /* Busy loop in userspace to elapse ITIMER_VIRTUAL */
@@ -66,15 +81,13 @@ static int check_diff(struct timeval sta
 	diff = end.tv_usec - start.tv_usec;
 	diff += (end.tv_sec - start.tv_sec) * USECS_PER_SEC;
 
-	if (abs(diff - DELAY * USECS_PER_SEC) > USECS_PER_SEC / 2) {
-		printf("Diff too high: %lld..", diff);
+	if (abs(diff - DELAY * USECS_PER_SEC) > USECS_PER_SEC / 2)
 		return -1;
-	}
 
 	return 0;
 }
 
-static int check_itimer(int which)
+static void check_itimer(int which, const char *name)
 {
 	int err;
 	struct timeval start, end;
@@ -82,17 +95,6 @@ static int check_itimer(int which)
 		.it_value.tv_sec = DELAY,
 	};
 
-	printf("Check itimer ");
-
-	if (which == ITIMER_VIRTUAL)
-		printf("virtual... ");
-	else if (which == ITIMER_PROF)
-		printf("prof... ");
-	else if (which == ITIMER_REAL)
-		printf("real... ");
-
-	fflush(stdout);
-
 	done = 0;
 
 	if (which == ITIMER_VIRTUAL)
@@ -103,16 +105,12 @@ static int check_itimer(int which)
 		signal(SIGALRM, sig_handler);
 
 	err = gettimeofday(&start, NULL);
-	if (err < 0) {
-		perror("Can't call gettimeofday()\n");
-		return -1;
-	}
+	if (err < 0)
+		fatal_error(name, "gettimeofday()");
 
 	err = setitimer(which, &val, NULL);
-	if (err < 0) {
-		perror("Can't set timer\n");
-		return -1;
-	}
+	if (err < 0)
+		fatal_error(name, "setitimer()");
 
 	if (which == ITIMER_VIRTUAL)
 		user_loop();
@@ -122,20 +120,16 @@ static int check_itimer(int which)
 		idle_loop();
 
 	err = gettimeofday(&end, NULL);
-	if (err < 0) {
-		perror("Can't call gettimeofday()\n");
-		return -1;
-	}
+	if (err < 0)
+		fatal_error(name, "gettimeofday()");
 
 	if (!check_diff(start, end))
-		printf("[OK]\n");
+		ksft_test_result_pass("check_itimer %s\n", name);
 	else
-		printf("[FAIL]\n");
-
-	return 0;
+		ksft_test_result_fail("check_itimer %s\n", name);
 }
 
-static int check_timer_create(int which)
+static void check_timer_create(int which, const char *name)
 {
 	int err;
 	timer_t id;
@@ -144,48 +138,32 @@ static int check_timer_create(int which)
 		.it_value.tv_sec = DELAY,
 	};
 
-	printf("Check timer_create() ");
-	if (which == CLOCK_THREAD_CPUTIME_ID) {
-		printf("per thread... ");
-	} else if (which == CLOCK_PROCESS_CPUTIME_ID) {
-		printf("per process... ");
-	}
-	fflush(stdout);
-
 	done = 0;
 	err = timer_create(which, NULL, &id);
-	if (err < 0) {
-		perror("Can't create timer\n");
-		return -1;
-	}
-	signal(SIGALRM, sig_handler);
+	if (err < 0)
+		fatal_error(name, "timer_create()");
+
+	if (signal(SIGALRM, sig_handler) == SIG_ERR)
+		fatal_error(name, "signal()");
 
 	err = gettimeofday(&start, NULL);
-	if (err < 0) {
-		perror("Can't call gettimeofday()\n");
-		return -1;
-	}
+	if (err < 0)
+		fatal_error(name, "gettimeofday()");
 
 	err = timer_settime(id, 0, &val, NULL);
-	if (err < 0) {
-		perror("Can't set timer\n");
-		return -1;
-	}
+	if (err < 0)
+		fatal_error(name, "timer_settime()");
 
 	user_loop();
 
 	err = gettimeofday(&end, NULL);
-	if (err < 0) {
-		perror("Can't call gettimeofday()\n");
-		return -1;
-	}
+	if (err < 0)
+		fatal_error(name, "gettimeofday()");
 
 	if (!check_diff(start, end))
-		printf("[OK]\n");
+		ksft_test_result_pass("check_timer_create %s\n", name);
 	else
-		printf("[FAIL]\n");
-
-	return 0;
+		ksft_test_result_fail("check_timer_create %s\n", name);
 }
 
 static int remain;
@@ -208,7 +186,7 @@ static void distribution_handler(int nr)
  * Test that all running threads _eventually_ receive CLOCK_PROCESS_CPUTIME_ID
  * timer signals. This primarily tests that the kernel does not favour any one.
  */
-static int check_timer_distribution(void)
+static void check_timer_distribution(void)
 {
 	const int nthreads = 10;
 	pthread_t threads[nthreads];
@@ -222,28 +200,22 @@ static int check_timer_distribution(void
 	int err, i;
 	timer_t id;
 
-	printf("Check timer_create() per process signal distribution... ");
-	fflush(stdout);
-
 	done = 0;
 	remain = nthreads + 1;  /* worker threads + this thread */
-	signal(SIGALRM, distribution_handler);
+	if (signal(SIGALRM, distribution_handler) == SIG_ERR)
+		fatal_error(NULL, "signal()");
+
 	err = timer_create(CLOCK_PROCESS_CPUTIME_ID, NULL, &id);
-	if (err < 0) {
-		perror("Can't create timer\n");
-		return -1;
-	}
+	if (err < 0)
+		fatal_error(NULL, "timer_create()");
+
 	err = timer_settime(id, 0, &val, NULL);
-	if (err < 0) {
-		perror("Can't set timer\n");
-		return -1;
-	}
+	if (err < 0)
+		fatal_error(NULL, "timer_settime()");
 
 	for (i = 0; i < nthreads; i++) {
-		if (pthread_create(&threads[i], NULL, distribution_thread, NULL)) {
-			perror("Can't create thread\n");
-			return -1;
-		}
+		if (pthread_create(&threads[i], NULL, distribution_thread, NULL))
+			fatal_error(NULL, "pthread_create()");
 	}
 
 	/* Wait for all threads to receive the signal. */
@@ -255,41 +227,29 @@ static int check_timer_distribution(void
 	}
 	done = 1;
 
-	if (timer_delete(id)) {
-		perror("Can't delete timer\n");
-		return -1;
-	}
+	if (timer_delete(id))
+		fatal_error(NULL, "timer_delete()");
 
 	for (i = 0; i < nthreads; i++) {
-		if (pthread_join(threads[i], NULL)) {
-			perror("Can't join thread\n");
-			return -1;
-		}
+		if (pthread_join(threads[i], NULL))
+			fatal_error(NULL, "pthread_join()");
 	}
 
 	if (now - start <= 5)
-		printf("[OK]\n");
+		ksft_test_result_pass("check_signal_distribution\n");
 	else
-		printf("%d [FAIL]\n", got_signal);
-	return 0;
+		ksft_test_result_fail("check_signal_distribution\n");
 }
 
 int main(int argc, char **argv)
 {
-	printf("Testing posix timers. False negative may happen on CPU execution \n");
-	printf("based timers if other threads run on the CPU...\n");
-
-	if (check_itimer(ITIMER_VIRTUAL) < 0)
-		return ksft_exit_fail();
+	ksft_print_header();
+	ksft_set_plan(6);
 
-	if (check_itimer(ITIMER_PROF) < 0)
-		return ksft_exit_fail();
-
-	if (check_itimer(ITIMER_REAL) < 0)
-		return ksft_exit_fail();
-
-	if (check_timer_create(CLOCK_THREAD_CPUTIME_ID) < 0)
-		return ksft_exit_fail();
+	check_itimer(ITIMER_VIRTUAL, "ITIMER_VIRTUAL");
+	check_itimer(ITIMER_PROF, "ITIMER_PROF");
+	check_itimer(ITIMER_REAL, "ITIMER_REAL");
+	check_timer_create(CLOCK_THREAD_CPUTIME_ID, "CLOCK_THREAD_CPUTIME_ID");
 
 	/*
 	 * It's unfortunately hard to reliably test a timer expiration
@@ -300,11 +260,8 @@ int main(int argc, char **argv)
 	 * to ensure true parallelism. So test only one thread until we
 	 * find a better solution.
 	 */
-	if (check_timer_create(CLOCK_PROCESS_CPUTIME_ID) < 0)
-		return ksft_exit_fail();
-
-	if (check_timer_distribution() < 0)
-		return ksft_exit_fail();
+	check_timer_create(CLOCK_PROCESS_CPUTIME_ID, "CLOCK_PROCESS_CPUTIME_ID");
+	check_timer_distribution();
 
-	return ksft_exit_pass();
+	ksft_finished();
 }
