[RFC 20/20] timens/selftest: Add timer offsets test

[Dmitry Safonov]

From: Andrei Vagin <avagin@xxxxxxxxxx>

Check that timer_create takes into account clock offsets.

Cc: linux-kselftest@xxxxxxxxxxxxxxx
Signed-off-by: Andrei Vagin <avagin@xxxxxxxxxx>
Signed-off-by: Dmitry Safonov <dima@xxxxxxxxxx>
---
 tools/testing/selftests/timens/.gitignore |  1 +
 tools/testing/selftests/timens/Makefile   |  3 +-
 tools/testing/selftests/timens/timer.c    | 95 +++++++++++++++++++++++++++++++
 3 files changed, 98 insertions(+), 1 deletion(-)
 create mode 100644 tools/testing/selftests/timens/timer.c

diff --git a/tools/testing/selftests/timens/.gitignore b/tools/testing/selftests/timens/.gitignore
index 94ffdd9cead7..3b7eda8f35ce 100644
--- a/tools/testing/selftests/timens/.gitignore
+++ b/tools/testing/selftests/timens/.gitignore
@@ -1,4 +1,5 @@
 clock_nanosleep
 procfs
 timens
+timer
 timerfd
diff --git a/tools/testing/selftests/timens/Makefile b/tools/testing/selftests/timens/Makefile
index f96f50d1fef8..ae1ffd24cc43 100644
--- a/tools/testing/selftests/timens/Makefile
+++ b/tools/testing/selftests/timens/Makefile
@@ -1,5 +1,6 @@
-TEST_GEN_PROGS := timens timerfd clock_nanosleep procfs
+TEST_GEN_PROGS := timens timerfd timer clock_nanosleep procfs
 
 CFLAGS := -Wall -Werror
+LDFLAGS := -lrt
 
 include ../lib.mk
diff --git a/tools/testing/selftests/timens/timer.c b/tools/testing/selftests/timens/timer.c
new file mode 100644
index 000000000000..e3a0951aadc8
--- /dev/null
+++ b/tools/testing/selftests/timens/timer.c
@@ -0,0 +1,95 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+#include <sched.h>
+
+#include <sys/syscall.h>
+#include <time.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <signal.h>
+#include <time.h>
+
+#include "log.h"
+
+#ifndef CLONE_NEWTIME
+#define CLONE_NEWTIME   0x00001000	  /* New time namespace */
+#endif
+
+int run_test(int clockid)
+{
+	struct itimerspec new_value;
+	struct timespec now;
+	long long elapsed;
+	timer_t fd;
+	int i;
+
+	if (clock_gettime(clockid, &now) == -1)
+		return pr_perror("clock_gettime");
+
+	for (i = 0; i < 2; i++) {
+		struct sigevent sevp = {.sigev_notify = SIGEV_NONE};
+		int flags = 0;
+
+		pr_msg("timerfd_settime: %d", "INFO", clockid);
+		new_value.it_value.tv_sec = 3600;
+		new_value.it_value.tv_nsec = 0;
+		new_value.it_interval.tv_sec = 1;
+		new_value.it_interval.tv_nsec = 0;
+
+		if (i == 1) {
+			new_value.it_value.tv_sec += now.tv_sec;
+			new_value.it_value.tv_nsec += now.tv_nsec;
+		}
+
+		if (timer_create(clockid, &sevp, &fd) == -1)
+			return pr_perror("timerfd_create");
+
+		if (i == 1)
+			flags |= TIMER_ABSTIME;
+		if (timer_settime(fd, flags, &new_value, NULL) == -1)
+			return pr_perror("timerfd_settime");
+
+		if (timer_gettime(fd, &new_value) == -1)
+			return pr_perror("timerfd_gettime");
+
+		elapsed = new_value.it_value.tv_sec;
+		if (abs(elapsed - 3600) > 60) {
+			pr_fail("elapsed: %lld\n", elapsed);
+			return 1;
+		}
+	}
+
+	printf("PASS\n");
+
+	return 0;
+}
+
+int main(int argc, char *argv[])
+{
+	struct timespec tp;
+	int ret;
+
+	if (unshare(CLONE_NEWTIME))
+		return pr_perror("unshare");
+
+	if (clock_gettime(CLOCK_MONOTONIC, &tp))
+		return pr_perror("clock_gettime");
+	tp.tv_sec -= 70 * 24 * 3600;
+	if (clock_settime(CLOCK_MONOTONIC, &tp))
+		return pr_perror("clock_settime");
+
+	if (clock_gettime(CLOCK_BOOTTIME, &tp))
+		return pr_perror("clock_gettime");
+	tp.tv_sec -= 9 * 24 * 3600;
+	tp.tv_nsec = 0;
+	if (clock_settime(CLOCK_BOOTTIME, &tp))
+		return pr_perror("clock_settime");
+
+	ret = 0;
+	ret |= run_test(CLOCK_BOOTTIME);
+	ret |= run_test(CLOCK_MONOTONIC);
+	return ret;
+}
+
-- 
2.13.6