[PATCHv6 34/36] selftest/timens: Add timer offsets test

[Dmitry Safonov <dima@arista.com>]

From: Andrei Vagin <avagin@openvz.org>

Check that timer_create() takes into account clock offsets.

Signed-off-by: Andrei Vagin <avagin@gmail.com>
Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
 tools/testing/selftests/timens/.gitignore |   1 +
 tools/testing/selftests/timens/Makefile   |   3 +-
 tools/testing/selftests/timens/timer.c    | 118 ++++++++++++++++++++++
 3 files changed, 121 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..45a9dd3cbb12
--- /dev/null
+++ b/tools/testing/selftests/timens/timer.c
@@ -0,0 +1,118 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+#include <sched.h>
+
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <sys/wait.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"
+#include "timens.h"
+
+int run_test(int clockid, struct timespec now)
+{
+	struct itimerspec new_value;
+	long long elapsed;
+	timer_t fd;
+	int i;
+
+	for (i = 0; i < 2; i++) {
+		struct sigevent sevp = {.sigev_notify = SIGEV_NONE};
+		int flags = 0;
+
+		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) {
+			ksft_test_result_fail("clockid: %d elapsed: %lld\n",
+					      clockid, elapsed);
+			return 1;
+		}
+	}
+
+	ksft_test_result_pass("clockid=%d\n", clockid);
+
+	return 0;
+}
+
+int main(int argc, char *argv[])
+{
+	int ret, status, len, fd;
+	char buf[4096];
+	pid_t pid;
+	struct timespec btime_now, mtime_now;
+
+	nscheck();
+
+	ksft_set_plan(3);
+
+	clock_gettime(CLOCK_MONOTONIC, &mtime_now);
+	clock_gettime(CLOCK_BOOTTIME, &btime_now);
+
+	if (unshare(CLONE_NEWTIME))
+		return pr_perror("unshare");
+
+	len = snprintf(buf, sizeof(buf), "%d %d 0\n%d %d 0",
+			CLOCK_MONOTONIC, 70 * 24 * 3600,
+			CLOCK_BOOTTIME, 9 * 24 * 3600);
+	fd = open("/proc/self/timens_offsets", O_WRONLY);
+	if (fd < 0)
+		return pr_perror("/proc/self/timens_offsets");
+
+	if (write(fd, buf, len) != len)
+		return pr_perror("/proc/self/timens_offsets");
+
+	close(fd);
+	mtime_now.tv_sec += 70 * 24 * 3600;
+	btime_now.tv_sec += 9 * 24 * 3600;
+
+	pid = fork();
+	if (pid < 0)
+		return pr_perror("Unable to fork");
+	if (pid == 0) {
+		ret = 0;
+		ret |= run_test(CLOCK_BOOTTIME, btime_now);
+		ret |= run_test(CLOCK_MONOTONIC, mtime_now);
+		ret |= run_test(CLOCK_BOOTTIME_ALARM, btime_now);
+
+		if (ret)
+			ksft_exit_fail();
+		ksft_exit_pass();
+		return ret;
+	}
+
+	if (waitpid(pid, &status, 0) != pid)
+		return pr_perror("Unable to wait the child process");
+
+	if (WIFEXITED(status))
+		return WEXITSTATUS(status);
+
+	return 1;
+}
+
-- 
2.22.0