Merge tag 'timers-core-2020-01-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer updates from Thomas Gleixner:
 "The timekeeping and timers departement provides:

   - Time namespace support:

     If a container migrates from one host to another then it expects
     that clocks based on MONOTONIC and BOOTTIME are not subject to
     disruption. Due to different boot time and non-suspended runtime
     these clocks can differ significantly on two hosts, in the worst
     case time goes backwards which is a violation of the POSIX
     requirements.

     The time namespace addresses this problem. It allows to set offsets
     for clock MONOTONIC and BOOTTIME once after creation and before
     tasks are associated with the namespace. These offsets are taken
     into account by timers and timekeeping including the VDSO.

     Offsets for wall clock based clocks (REALTIME/TAI) are not provided
     by this mechanism. While in theory possible, the overhead and code
     complexity would be immense and not justified by the esoteric
     potential use cases which were discussed at Plumbers '18.

     The overhead for tasks in the root namespace (ie where host time
     offsets = 0) is in the noise and great effort was made to ensure
     that especially in the VDSO. If time namespace is disabled in the
     kernel configuration the code is compiled out.

     Kudos to Andrei Vagin and Dmitry Sofanov who implemented this
     feature and kept on for more than a year addressing review
     comments, finding better solutions. A pleasant experience.

   - Overhaul of the alarmtimer device dependency handling to ensure
     that the init/suspend/resume ordering is correct.

   - A new clocksource/event driver for Microchip PIT64

   - Suspend/resume support for the Hyper-V clocksource

   - The usual pile of fixes, updates and improvements mostly in the
     driver code"

* tag 'timers-core-2020-01-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits)
  alarmtimer: Make alarmtimer_get_rtcdev() a stub when CONFIG_RTC_CLASS=n
  alarmtimer: Use wakeup source from alarmtimer platform device
  alarmtimer: Make alarmtimer platform device child of RTC device
  alarmtimer: Update alarmtimer_get_rtcdev() docs to reflect reality
  hrtimer: Add missing sparse annotation for __run_timer()
  lib/vdso: Only read hrtimer_res when needed in __cvdso_clock_getres()
  MIPS: vdso: Define BUILD_VDSO32 when building a 32bit kernel
  clocksource/drivers/hyper-v: Set TSC clocksource as default w/ InvariantTSC
  clocksource/drivers/hyper-v: Untangle stimers and timesync from clocksources
  clocksource/drivers/timer-microchip-pit64b: Fix sparse warning
  clocksource/drivers/exynos_mct: Rename Exynos to lowercase
  clocksource/drivers/timer-ti-dm: Fix uninitialized pointer access
  clocksource/drivers/timer-ti-dm: Switch to platform_get_irq
  clocksource/drivers/timer-ti-dm: Convert to devm_platform_ioremap_resource
  clocksource/drivers/em_sti: Fix variable declaration in em_sti_probe
  clocksource/drivers/em_sti: Convert to devm_platform_ioremap_resource
  clocksource/drivers/bcm2835_timer: Fix memory leak of timer
  clocksource/drivers/cadence-ttc: Use ttc driver as platform driver
  clocksource/drivers/timer-microchip-pit64b: Add Microchip PIT64B support
  clocksource/drivers/hyper-v: Reserve PAGE_SIZE space for tsc page
  ...

14 files changed, 1069 insertions, 2 deletions

diff --git a/tools/perf/examples/bpf/5sec.c b/tools/perf/examples/bpf/5sec.c
index b9c203219691..e6b6181c6dc6 100644
--- a/tools/perf/examples/bpf/5sec.c
+++ b/tools/perf/examples/bpf/5sec.c
@@ -41,9 +41,11 @@
 
 #include <bpf.h>
 
-int probe(hrtimer_nanosleep, rqtp->tv_sec)(void *ctx, int err, long sec)
+#define NSEC_PER_SEC	1000000000L
+
+int probe(hrtimer_nanosleep, rqtp)(void *ctx, int err, long long sec)
 {
-	return sec == 5;
+	return sec / NSEC_PER_SEC == 5ULL;
 }
 
 license(GPL);
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index b001c602414b..c4939a2a5f5d 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -50,6 +50,7 @@ TARGETS += splice
 TARGETS += static_keys
 TARGETS += sync
 TARGETS += sysctl
+TARGETS += timens
 ifneq (1, $(quicktest))
 TARGETS += timers
 endif
diff --git a/tools/testing/selftests/timens/.gitignore b/tools/testing/selftests/timens/.gitignore
new file mode 100644
index 000000000000..789f21e81028
--- /dev/null
+++ b/tools/testing/selftests/timens/.gitignore
@@ -0,0 +1,8 @@
+clock_nanosleep
+exec
+gettime_perf
+gettime_perf_cold
+procfs
+timens
+timer
+timerfd
diff --git a/tools/testing/selftests/timens/Makefile b/tools/testing/selftests/timens/Makefile
new file mode 100644
index 000000000000..e9fb30bd8aeb
--- /dev/null
+++ b/tools/testing/selftests/timens/Makefile
@@ -0,0 +1,7 @@
+TEST_GEN_PROGS := timens timerfd timer clock_nanosleep procfs exec
+TEST_GEN_PROGS_EXTENDED := gettime_perf
+
+CFLAGS := -Wall -Werror -pthread
+LDFLAGS := -lrt -ldl
+
+include ../lib.mk
diff --git a/tools/testing/selftests/timens/clock_nanosleep.c b/tools/testing/selftests/timens/clock_nanosleep.c
new file mode 100644
index 000000000000..8e7b7c72ef65
--- /dev/null
+++ b/tools/testing/selftests/timens/clock_nanosleep.c
@@ -0,0 +1,149 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+#include <sched.h>
+
+#include <sys/timerfd.h>
+#include <sys/syscall.h>
+#include <time.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <pthread.h>
+#include <signal.h>
+#include <string.h>
+
+#include "log.h"
+#include "timens.h"
+
+void test_sig(int sig)
+{
+	if (sig == SIGUSR2)
+		pthread_exit(NULL);
+}
+
+struct thread_args {
+	struct timespec *now, *rem;
+	pthread_mutex_t *lock;
+	int clockid;
+	int abs;
+};
+
+void *call_nanosleep(void *_args)
+{
+	struct thread_args *args = _args;
+
+	clock_nanosleep(args->clockid, args->abs ? TIMER_ABSTIME : 0, args->now, args->rem);
+	pthread_mutex_unlock(args->lock);
+	return NULL;
+}
+
+int run_test(int clockid, int abs)
+{
+	struct timespec now = {}, rem;
+	struct thread_args args = { .now = &now, .rem = &rem, .clockid = clockid};
+	struct timespec start;
+	pthread_mutex_t lock;
+	pthread_t thread;
+	int j, ok, ret;
+
+	signal(SIGUSR1, test_sig);
+	signal(SIGUSR2, test_sig);
+
+	pthread_mutex_init(&lock, NULL);
+	pthread_mutex_lock(&lock);
+
+	if (clock_gettime(clockid, &start) == -1) {
+		if (errno == EINVAL && check_skip(clockid))
+			return 0;
+		return pr_perror("clock_gettime");
+	}
+
+
+	if (abs) {
+		now.tv_sec = start.tv_sec;
+		now.tv_nsec = start.tv_nsec;
+	}
+
+	now.tv_sec += 3600;
+	args.abs = abs;
+	args.lock = &lock;
+	ret = pthread_create(&thread, NULL, call_nanosleep, &args);
+	if (ret != 0) {
+		pr_err("Unable to create a thread: %s", strerror(ret));
+		return 1;
+	}
+
+	/* Wait when the thread will call clock_nanosleep(). */
+	ok = 0;
+	for (j = 0; j < 8; j++) {
+		/* The maximum timeout is about 5 seconds. */
+		usleep(10000 << j);
+
+		/* Try to interrupt clock_nanosleep(). */
+		pthread_kill(thread, SIGUSR1);
+
+		usleep(10000 << j);
+		/* Check whether clock_nanosleep() has been interrupted or not. */
+		if (pthread_mutex_trylock(&lock) == 0) {
+			/**/
+			ok = 1;
+			break;
+		}
+	}
+	if (!ok)
+		pthread_kill(thread, SIGUSR2);
+	pthread_join(thread, NULL);
+	pthread_mutex_destroy(&lock);
+
+	if (!ok) {
+		ksft_test_result_pass("clockid: %d abs:%d timeout\n", clockid, abs);
+		return 1;
+	}
+
+	if (rem.tv_sec < 3300 || rem.tv_sec > 3900) {
+		pr_fail("clockid: %d abs: %d remain: %ld\n",
+			clockid, abs, rem.tv_sec);
+		return 1;
+	}
+	ksft_test_result_pass("clockid: %d abs:%d\n", clockid, abs);
+
+	return 0;
+}
+
+int main(int argc, char *argv[])
+{
+	int ret, nsfd;
+
+	nscheck();
+
+	ksft_set_plan(4);
+
+	check_config_posix_timers();
+
+	if (unshare_timens())
+		return 1;
+
+	if (_settime(CLOCK_MONOTONIC, 7 * 24 * 3600))
+		return 1;
+	if (_settime(CLOCK_BOOTTIME, 9 * 24 * 3600))
+		return 1;
+
+	nsfd = open("/proc/self/ns/time_for_children", O_RDONLY);
+	if (nsfd < 0)
+		return pr_perror("Unable to open timens_for_children");
+
+	if (setns(nsfd, CLONE_NEWTIME))
+		return pr_perror("Unable to set timens");
+
+	ret = 0;
+	ret |= run_test(CLOCK_MONOTONIC, 0);
+	ret |= run_test(CLOCK_MONOTONIC, 1);
+	ret |= run_test(CLOCK_BOOTTIME_ALARM, 0);
+	ret |= run_test(CLOCK_BOOTTIME_ALARM, 1);
+
+	if (ret)
+		ksft_exit_fail();
+	ksft_exit_pass();
+	return ret;
+}
diff --git a/tools/testing/selftests/timens/config b/tools/testing/selftests/timens/config
new file mode 100644
index 000000000000..4480620f6f49
--- /dev/null
+++ b/tools/testing/selftests/timens/config
@@ -0,0 +1 @@
+CONFIG_TIME_NS=y
diff --git a/tools/testing/selftests/timens/exec.c b/tools/testing/selftests/timens/exec.c
new file mode 100644
index 000000000000..87b47b557a7a
--- /dev/null
+++ b/tools/testing/selftests/timens/exec.c
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <sched.h>
+#include <stdio.h>
+#include <stdbool.h>
+#include <sys/stat.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <time.h>
+#include <unistd.h>
+#include <time.h>
+#include <string.h>
+
+#include "log.h"
+#include "timens.h"
+
+#define OFFSET (36000)
+
+int main(int argc, char *argv[])
+{
+	struct timespec now, tst;
+	int status, i;
+	pid_t pid;
+
+	if (argc > 1) {
+		if (sscanf(argv[1], "%ld", &now.tv_sec) != 1)
+			return pr_perror("sscanf");
+
+		for (i = 0; i < 2; i++) {
+			_gettime(CLOCK_MONOTONIC, &tst, i);
+			if (abs(tst.tv_sec - now.tv_sec) > 5)
+				return pr_fail("%ld %ld\n", now.tv_sec, tst.tv_sec);
+		}
+		return 0;
+	}
+
+	nscheck();
+
+	ksft_set_plan(1);
+
+	clock_gettime(CLOCK_MONOTONIC, &now);
+
+	if (unshare_timens())
+		return 1;
+
+	if (_settime(CLOCK_MONOTONIC, OFFSET))
+		return 1;
+
+	for (i = 0; i < 2; i++) {
+		_gettime(CLOCK_MONOTONIC, &tst, i);
+		if (abs(tst.tv_sec - now.tv_sec) > 5)
+			return pr_fail("%ld %ld\n",
+					now.tv_sec, tst.tv_sec);
+	}
+
+	if (argc > 1)
+		return 0;
+
+	pid = fork();
+	if (pid < 0)
+		return pr_perror("fork");
+
+	if (pid == 0) {
+		char now_str[64];
+		char *cargv[] = {"exec", now_str, NULL};
+		char *cenv[] = {NULL};
+
+		/* Check that a child process is in the new timens. */
+		for (i = 0; i < 2; i++) {
+			_gettime(CLOCK_MONOTONIC, &tst, i);
+			if (abs(tst.tv_sec - now.tv_sec - OFFSET) > 5)
+				return pr_fail("%ld %ld\n",
+						now.tv_sec + OFFSET, tst.tv_sec);
+		}
+
+		/* Check for proper vvar offsets after execve. */
+		snprintf(now_str, sizeof(now_str), "%ld", now.tv_sec + OFFSET);
+		execve("/proc/self/exe", cargv, cenv);
+		return pr_perror("execve");
+	}
+
+	if (waitpid(pid, &status, 0) != pid)
+		return pr_perror("waitpid");
+
+	if (status)
+		ksft_exit_fail();
+
+	ksft_test_result_pass("exec\n");
+	ksft_exit_pass();
+	return 0;
+}
diff --git a/tools/testing/selftests/timens/gettime_perf.c b/tools/testing/selftests/timens/gettime_perf.c
new file mode 100644
index 000000000000..7bf841a3967b
--- /dev/null
+++ b/tools/testing/selftests/timens/gettime_perf.c
@@ -0,0 +1,95 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sched.h>
+#include <time.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <dlfcn.h>
+
+#include "log.h"
+#include "timens.h"
+
+typedef int (*vgettime_t)(clockid_t, struct timespec *);
+
+vgettime_t vdso_clock_gettime;
+
+static void fill_function_pointers(void)
+{
+	void *vdso = dlopen("linux-vdso.so.1",
+			    RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);
+	if (!vdso)
+		vdso = dlopen("linux-gate.so.1",
+			      RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);
+	if (!vdso) {
+		pr_err("[WARN]\tfailed to find vDSO\n");
+		return;
+	}
+
+	vdso_clock_gettime = (vgettime_t)dlsym(vdso, "__vdso_clock_gettime");
+	if (!vdso_clock_gettime)
+		pr_err("Warning: failed to find clock_gettime in vDSO\n");
+
+}
+
+static void test(clock_t clockid, char *clockstr, bool in_ns)
+{
+	struct timespec tp, start;
+	long i = 0;
+	const int timeout = 3;
+
+	vdso_clock_gettime(clockid, &start);
+	tp = start;
+	for (tp = start; start.tv_sec + timeout > tp.tv_sec ||
+			 (start.tv_sec + timeout == tp.tv_sec &&
+			  start.tv_nsec > tp.tv_nsec); i++) {
+		vdso_clock_gettime(clockid, &tp);
+	}
+
+	ksft_test_result_pass("%s:\tclock: %10s\tcycles:\t%10ld\n",
+			      in_ns ? "ns" : "host", clockstr, i);
+}
+
+int main(int argc, char *argv[])
+{
+	time_t offset = 10;
+	int nsfd;
+
+	ksft_set_plan(8);
+
+	fill_function_pointers();
+
+	test(CLOCK_MONOTONIC, "monotonic", false);
+	test(CLOCK_MONOTONIC_COARSE, "monotonic-coarse", false);
+	test(CLOCK_MONOTONIC_RAW, "monotonic-raw", false);
+	test(CLOCK_BOOTTIME, "boottime", false);
+
+	nscheck();
+
+	if (unshare_timens())
+		return 1;
+
+	nsfd = open("/proc/self/ns/time_for_children", O_RDONLY);
+	if (nsfd < 0)
+		return pr_perror("Can't open a time namespace");
+
+	if (_settime(CLOCK_MONOTONIC, offset))
+		return 1;
+	if (_settime(CLOCK_BOOTTIME, offset))
+		return 1;
+
+	if (setns(nsfd, CLONE_NEWTIME))
+		return pr_perror("setns");
+
+	test(CLOCK_MONOTONIC, "monotonic", true);
+	test(CLOCK_MONOTONIC_COARSE, "monotonic-coarse", true);
+	test(CLOCK_MONOTONIC_RAW, "monotonic-raw", true);
+	test(CLOCK_BOOTTIME, "boottime", true);
+
+	ksft_exit_pass();
+	return 0;
+}
diff --git a/tools/testing/selftests/timens/log.h b/tools/testing/selftests/timens/log.h
new file mode 100644
index 000000000000..db64df2a8483
--- /dev/null
+++ b/tools/testing/selftests/timens/log.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __SELFTEST_TIMENS_LOG_H__
+#define __SELFTEST_TIMENS_LOG_H__
+
+#define pr_msg(fmt, lvl, ...)						\
+	ksft_print_msg("[%s] (%s:%d)\t" fmt "\n",			\
+			lvl, __FILE__, __LINE__, ##__VA_ARGS__)
+
+#define pr_p(func, fmt, ...)	func(fmt ": %m", ##__VA_ARGS__)
+
+#define pr_err(fmt, ...)						\
+	({								\
+		ksft_test_result_error(fmt "\n", ##__VA_ARGS__);		\
+		-1;							\
+	})
+
+#define pr_fail(fmt, ...)					\
+	({							\
+		ksft_test_result_fail(fmt, ##__VA_ARGS__);	\
+		-1;						\
+	})
+
+#define pr_perror(fmt, ...)	pr_p(pr_err, fmt, ##__VA_ARGS__)
+
+#endif
diff --git a/tools/testing/selftests/timens/procfs.c b/tools/testing/selftests/timens/procfs.c
new file mode 100644
index 000000000000..43d93f4006b9
--- /dev/null
+++ b/tools/testing/selftests/timens/procfs.c
@@ -0,0 +1,144 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <math.h>
+#include <sched.h>
+#include <stdio.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <time.h>
+#include <unistd.h>
+#include <time.h>
+
+#include "log.h"
+#include "timens.h"
+
+/*
+ * Test shouldn't be run for a day, so add 10 days to child
+ * time and check parent's time to be in the same day.
+ */
+#define MAX_TEST_TIME_SEC		(60*5)
+#define DAY_IN_SEC			(60*60*24)
+#define TEN_DAYS_IN_SEC			(10*DAY_IN_SEC)
+
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+
+static int child_ns, parent_ns;
+
+static int switch_ns(int fd)
+{
+	if (setns(fd, CLONE_NEWTIME))
+		return pr_perror("setns()");
+
+	return 0;
+}
+
+static int init_namespaces(void)
+{
+	char path[] = "/proc/self/ns/time_for_children";
+	struct stat st1, st2;
+
+	parent_ns = open(path, O_RDONLY);
+	if (parent_ns <= 0)
+		return pr_perror("Unable to open %s", path);
+
+	if (fstat(parent_ns, &st1))
+		return pr_perror("Unable to stat the parent timens");
+
+	if (unshare_timens())
+		return -1;
+
+	child_ns = open(path, O_RDONLY);
+	if (child_ns <= 0)
+		return pr_perror("Unable to open %s", path);
+
+	if (fstat(child_ns, &st2))
+		return pr_perror("Unable to stat the timens");
+
+	if (st1.st_ino == st2.st_ino)
+		return pr_err("The same child_ns after CLONE_NEWTIME");
+
+	if (_settime(CLOCK_BOOTTIME, TEN_DAYS_IN_SEC))
+		return -1;
+
+	return 0;
+}
+
+static int read_proc_uptime(struct timespec *uptime)
+{
+	unsigned long up_sec, up_nsec;
+	FILE *proc;
+
+	proc = fopen("/proc/uptime", "r");
+	if (proc == NULL) {
+		pr_perror("Unable to open /proc/uptime");
+		return -1;
+	}
+
+	if (fscanf(proc, "%lu.%02lu", &up_sec, &up_nsec) != 2) {
+		if (errno) {
+			pr_perror("fscanf");
+			return -errno;
+		}
+		pr_err("failed to parse /proc/uptime");
+		return -1;
+	}
+	fclose(proc);
+
+	uptime->tv_sec = up_sec;
+	uptime->tv_nsec = up_nsec;
+	return 0;
+}
+
+static int check_uptime(void)
+{
+	struct timespec uptime_new, uptime_old;
+	time_t uptime_expected;
+	double prec = MAX_TEST_TIME_SEC;
+
+	if (switch_ns(parent_ns))
+		return pr_err("switch_ns(%d)", parent_ns);
+
+	if (read_proc_uptime(&uptime_old))
+		return 1;
+
+	if (switch_ns(child_ns))
+		return pr_err("switch_ns(%d)", child_ns);
+
+	if (read_proc_uptime(&uptime_new))
+		return 1;
+
+	uptime_expected = uptime_old.tv_sec + TEN_DAYS_IN_SEC;
+	if (fabs(difftime(uptime_new.tv_sec, uptime_expected)) > prec) {
+		pr_fail("uptime in /proc/uptime: old %ld, new %ld [%ld]",
+			uptime_old.tv_sec, uptime_new.tv_sec,
+			uptime_old.tv_sec + TEN_DAYS_IN_SEC);
+		return 1;
+	}
+
+	ksft_test_result_pass("Passed for /proc/uptime\n");
+	return 0;
+}
+
+int main(int argc, char *argv[])
+{
+	int ret = 0;
+
+	nscheck();
+
+	ksft_set_plan(1);
+
+	if (init_namespaces())
+		return 1;
+
+	ret |= check_uptime();
+
+	if (ret)
+		ksft_exit_fail();
+	ksft_exit_pass();
+	return ret;
+}
diff --git a/tools/testing/selftests/timens/timens.c b/tools/testing/selftests/timens/timens.c
new file mode 100644
index 000000000000..559d26e21ba0
--- /dev/null
+++ b/tools/testing/selftests/timens/timens.c
@@ -0,0 +1,190 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <sched.h>
+#include <stdio.h>
+#include <stdbool.h>
+#include <sys/stat.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <time.h>
+#include <unistd.h>
+#include <time.h>
+#include <string.h>
+
+#include "log.h"
+#include "timens.h"
+
+/*
+ * Test shouldn't be run for a day, so add 10 days to child
+ * time and check parent's time to be in the same day.
+ */
+#define DAY_IN_SEC			(60*60*24)
+#define TEN_DAYS_IN_SEC			(10*DAY_IN_SEC)
+
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+
+struct test_clock {
+	clockid_t id;
+	char *name;
+	/*
+	 * off_id is -1 if a clock has own offset, or it contains an index
+	 * which contains a right offset of this clock.
+	 */
+	int off_id;
+	time_t offset;
+};
+
+#define ct(clock, off_id)	{ clock, #clock, off_id }
+static struct test_clock clocks[] = {
+	ct(CLOCK_BOOTTIME, -1),
+	ct(CLOCK_BOOTTIME_ALARM, 1),
+	ct(CLOCK_MONOTONIC, -1),
+	ct(CLOCK_MONOTONIC_COARSE, 1),
+	ct(CLOCK_MONOTONIC_RAW, 1),
+};
+#undef ct
+
+static int child_ns, parent_ns = -1;
+
+static int switch_ns(int fd)
+{
+	if (setns(fd, CLONE_NEWTIME)) {
+		pr_perror("setns()");
+		return -1;
+	}
+
+	return 0;
+}
+
+static int init_namespaces(void)
+{
+	char path[] = "/proc/self/ns/time_for_children";
+	struct stat st1, st2;
+
+	if (parent_ns == -1) {
+		parent_ns = open(path, O_RDONLY);
+		if (parent_ns <= 0)
+			return pr_perror("Unable to open %s", path);
+	}
+
+	if (fstat(parent_ns, &st1))
+		return pr_perror("Unable to stat the parent timens");
+
+	if (unshare_timens())
+		return  -1;
+
+	child_ns = open(path, O_RDONLY);
+	if (child_ns <= 0)
+		return pr_perror("Unable to open %s", path);
+
+	if (fstat(child_ns, &st2))
+		return pr_perror("Unable to stat the timens");
+
+	if (st1.st_ino == st2.st_ino)
+		return pr_perror("The same child_ns after CLONE_NEWTIME");
+
+	return 0;
+}
+
+static int test_gettime(clockid_t clock_index, bool raw_syscall, time_t offset)
+{
+	struct timespec child_ts_new, parent_ts_old, cur_ts;
+	char *entry = raw_syscall ? "syscall" : "vdso";
+	double precision = 0.0;
+
+	if (check_skip(clocks[clock_index].id))
+		return 0;
+
+	switch (clocks[clock_index].id) {
+	case CLOCK_MONOTONIC_COARSE:
+	case CLOCK_MONOTONIC_RAW:
+		precision = -2.0;
+		break;
+	}
+
+	if (switch_ns(parent_ns))
+		return pr_err("switch_ns(%d)", child_ns);
+
+	if (_gettime(clocks[clock_index].id, &parent_ts_old, raw_syscall))
+		return -1;
+
+	child_ts_new.tv_nsec = parent_ts_old.tv_nsec;
+	child_ts_new.tv_sec = parent_ts_old.tv_sec + offset;
+
+	if (switch_ns(child_ns))
+		return pr_err("switch_ns(%d)", child_ns);
+
+	if (_gettime(clocks[clock_index].id, &cur_ts, raw_syscall))
+		return -1;
+
+	if (difftime(cur_ts.tv_sec, child_ts_new.tv_sec) < precision) {
+		ksft_test_result_fail(
+			"Child's %s (%s) time has not changed: %lu -> %lu [%lu]\n",
+			clocks[clock_index].name, entry, parent_ts_old.tv_sec,
+			child_ts_new.tv_sec, cur_ts.tv_sec);
+		return -1;
+	}
+
+	if (switch_ns(parent_ns))
+		return pr_err("switch_ns(%d)", parent_ns);
+
+	if (_gettime(clocks[clock_index].id, &cur_ts, raw_syscall))
+		return -1;
+
+	if (difftime(cur_ts.tv_sec, parent_ts_old.tv_sec) > DAY_IN_SEC) {
+		ksft_test_result_fail(
+			"Parent's %s (%s) time has changed: %lu -> %lu [%lu]\n",
+			clocks[clock_index].name, entry, parent_ts_old.tv_sec,
+			child_ts_new.tv_sec, cur_ts.tv_sec);
+		/* Let's play nice and put it closer to original */
+		clock_settime(clocks[clock_index].id, &cur_ts);
+		return -1;
+	}
+
+	ksft_test_result_pass("Passed for %s (%s)\n",
+				clocks[clock_index].name, entry);
+	return 0;
+}
+
+int main(int argc, char *argv[])
+{
+	unsigned int i;
+	time_t offset;
+	int ret = 0;
+
+	nscheck();
+
+	check_config_posix_timers();
+
+	ksft_set_plan(ARRAY_SIZE(clocks) * 2);
+
+	if (init_namespaces())
+		return 1;
+
+	/* Offsets have to be set before tasks enter the namespace. */
+	for (i = 0; i < ARRAY_SIZE(clocks); i++) {
+		if (clocks[i].off_id != -1)
+			continue;
+		offset = TEN_DAYS_IN_SEC + i * 1000;
+		clocks[i].offset = offset;
+		if (_settime(clocks[i].id, offset))
+			return 1;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(clocks); i++) {
+		if (clocks[i].off_id != -1)
+			offset = clocks[clocks[i].off_id].offset;
+		else
+			offset = clocks[i].offset;
+		ret |= test_gettime(i, true, offset);
+		ret |= test_gettime(i, false, offset);
+	}
+
+	if (ret)
+		ksft_exit_fail();
+
+	ksft_exit_pass();
+	return !!ret;
+}
diff --git a/tools/testing/selftests/timens/timens.h b/tools/testing/selftests/timens/timens.h
new file mode 100644
index 000000000000..e09e7e39bc52
--- /dev/null
+++ b/tools/testing/selftests/timens/timens.h
@@ -0,0 +1,100 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __TIMENS_H__
+#define __TIMENS_H__
+
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdbool.h>
+
+#include "../kselftest.h"
+
+#ifndef CLONE_NEWTIME
+# define CLONE_NEWTIME	0x00000080
+#endif
+
+static int config_posix_timers = true;
+
+static inline void check_config_posix_timers(void)
+{
+	if (timer_create(-1, 0, 0) == -1 && errno == ENOSYS)
+		config_posix_timers = false;
+}
+
+static inline bool check_skip(int clockid)
+{
+	if (config_posix_timers)
+		return false;
+
+	switch (clockid) {
+	/* Only these clocks are supported without CONFIG_POSIX_TIMERS. */
+	case CLOCK_BOOTTIME:
+	case CLOCK_MONOTONIC:
+	case CLOCK_REALTIME:
+		return false;
+	default:
+		ksft_test_result_skip("Posix Clocks & timers are not supported\n");
+		return true;
+	}
+
+	return false;
+}
+
+static inline int unshare_timens(void)
+{
+	if (unshare(CLONE_NEWTIME)) {
+		if (errno == EPERM)
+			ksft_exit_skip("need to run as root\n");
+		return pr_perror("Can't unshare() timens");
+	}
+	return 0;
+}
+
+static inline int _settime(clockid_t clk_id, time_t offset)
+{
+	int fd, len;
+	char buf[4096];
+
+	if (clk_id == CLOCK_MONOTONIC_COARSE || clk_id == CLOCK_MONOTONIC_RAW)
+		clk_id = CLOCK_MONOTONIC;
+
+	len = snprintf(buf, sizeof(buf), "%d %ld 0", clk_id, offset);
+
+	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);
+
+	return 0;
+}
+
+static inline int _gettime(clockid_t clk_id, struct timespec *res, bool raw_syscall)
+{
+	int err;
+
+	if (!raw_syscall) {
+		if (clock_gettime(clk_id, res)) {
+			pr_perror("clock_gettime(%d)", (int)clk_id);
+			return -1;
+		}
+		return 0;
+	}
+
+	err = syscall(SYS_clock_gettime, clk_id, res);
+	if (err)
+		pr_perror("syscall(SYS_clock_gettime(%d))", (int)clk_id);
+
+	return err;
+}
+
+static inline void nscheck(void)
+{
+	if (access("/proc/self/ns/time", F_OK) < 0)
+		ksft_exit_skip("Time namespaces are not supported\n");
+}
+
+#endif
diff --git a/tools/testing/selftests/timens/timer.c b/tools/testing/selftests/timens/timer.c
new file mode 100644
index 000000000000..0cca7aafc4bd
--- /dev/null
+++ b/tools/testing/selftests/timens/timer.c
@@ -0,0 +1,122 @@
+// 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) {
+			if (errno == ENOSYS) {
+				ksft_test_result_skip("Posix Clocks & timers are supported\n");
+				return 0;
+			}
+			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_timens())
+		return 1;
+
+	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;
+}
diff --git a/tools/testing/selftests/timens/timerfd.c b/tools/testing/selftests/timens/timerfd.c
new file mode 100644
index 000000000000..eff1ec5ff215
--- /dev/null
+++ b/tools/testing/selftests/timens/timerfd.c
@@ -0,0 +1,128 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+#include <sched.h>
+
+#include <sys/timerfd.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 "log.h"
+#include "timens.h"
+
+static int tclock_gettime(clock_t clockid, struct timespec *now)
+{
+	if (clockid == CLOCK_BOOTTIME_ALARM)
+		clockid = CLOCK_BOOTTIME;
+	return clock_gettime(clockid, now);
+}
+
+int run_test(int clockid, struct timespec now)
+{
+	struct itimerspec new_value;
+	long long elapsed;
+	int fd, i;
+
+	if (tclock_gettime(clockid, &now))
+		return pr_perror("clock_gettime(%d)", clockid);
+
+	for (i = 0; i < 2; i++) {
+		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;
+		}
+
+		fd = timerfd_create(clockid, 0);
+		if (fd == -1)
+			return pr_perror("timerfd_create(%d)", clockid);
+
+		if (i == 1)
+			flags |= TFD_TIMER_ABSTIME;
+
+		if (timerfd_settime(fd, flags, &new_value, NULL))
+			return pr_perror("timerfd_settime(%d)", clockid);
+
+		if (timerfd_gettime(fd, &new_value))
+			return pr_perror("timerfd_gettime(%d)", clockid);
+
+		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;
+		}
+
+		close(fd);
+	}
+
+	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_timens())
+		return 1;
+
+	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;
+}