16 files changed, 1069 insertions, 13 deletions

diff --git a/tools/testing/nvdimm/Kbuild b/tools/testing/nvdimm/Kbuild
index 6aca8d5be159..dbebf05f5931 100644
--- a/tools/testing/nvdimm/Kbuild
+++ b/tools/testing/nvdimm/Kbuild
@@ -1,10 +1,9 @@
 # SPDX-License-Identifier: GPL-2.0
 ldflags-y += --wrap=ioremap_wc
 ldflags-y += --wrap=memremap
-ldflags-y += --wrap=devm_ioremap_nocache
+ldflags-y += --wrap=devm_ioremap
 ldflags-y += --wrap=devm_memremap
 ldflags-y += --wrap=devm_memunmap
-ldflags-y += --wrap=ioremap_nocache
 ldflags-y += --wrap=ioremap
 ldflags-y += --wrap=iounmap
 ldflags-y += --wrap=memunmap
diff --git a/tools/testing/nvdimm/test/iomap.c b/tools/testing/nvdimm/test/iomap.c
index 6271ac757a4b..03e40b3b0106 100644
--- a/tools/testing/nvdimm/test/iomap.c
+++ b/tools/testing/nvdimm/test/iomap.c
@@ -73,7 +73,7 @@ void __iomem *__nfit_test_ioremap(resource_size_t offset, unsigned long size,
 	return fallback_fn(offset, size);
 }
 
-void __iomem *__wrap_devm_ioremap_nocache(struct device *dev,
+void __iomem *__wrap_devm_ioremap(struct device *dev,
 		resource_size_t offset, unsigned long size)
 {
 	struct nfit_test_resource *nfit_res = get_nfit_res(offset);
@@ -81,9 +81,9 @@ void __iomem *__wrap_devm_ioremap_nocache(struct device *dev,
 	if (nfit_res)
 		return (void __iomem *) nfit_res->buf + offset
 			- nfit_res->res.start;
-	return devm_ioremap_nocache(dev, offset, size);
+	return devm_ioremap(dev, offset, size);
 }
-EXPORT_SYMBOL(__wrap_devm_ioremap_nocache);
+EXPORT_SYMBOL(__wrap_devm_ioremap);
 
 void *__wrap_devm_memremap(struct device *dev, resource_size_t offset,
 		size_t size, unsigned long flags)
@@ -187,12 +187,6 @@ void __wrap_devm_memunmap(struct device *dev, void *addr)
 }
 EXPORT_SYMBOL(__wrap_devm_memunmap);
 
-void __iomem *__wrap_ioremap_nocache(resource_size_t offset, unsigned long size)
-{
-	return __nfit_test_ioremap(offset, size, ioremap_nocache);
-}
-EXPORT_SYMBOL(__wrap_ioremap_nocache);
-
 void __iomem *__wrap_ioremap(resource_size_t offset, unsigned long size)
 {
 	return __nfit_test_ioremap(offset, size, ioremap);
diff --git a/tools/testing/nvdimm/test/nfit_test.h b/tools/testing/nvdimm/test/nfit_test.h
index 0bf5640f1f07..db3c07beb9d1 100644
--- a/tools/testing/nvdimm/test/nfit_test.h
+++ b/tools/testing/nvdimm/test/nfit_test.h
@@ -207,8 +207,6 @@ typedef struct nfit_test_resource *(*nfit_test_lookup_fn)(resource_size_t);
 typedef union acpi_object *(*nfit_test_evaluate_dsm_fn)(acpi_handle handle,
 		 const guid_t *guid, u64 rev, u64 func,
 		 union acpi_object *argv4);
-void __iomem *__wrap_ioremap_nocache(resource_size_t offset,
-		unsigned long size);
 void __wrap_iounmap(volatile void __iomem *addr);
 void nfit_test_setup(nfit_test_lookup_fn lookup,
 		nfit_test_evaluate_dsm_fn evaluate);
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;
+}