[PATCH 4/4] selftests: add clone3() in time namespace test

[Adrian Reber]

This adds a test to use clone3() with CLONE_NEWTIME. The test tries to
set CLOCK_BOOTTIME to 1 in the new process in the new time namespace and
CLOCK_MONOTONIC to +10000.

Signed-off-by: Adrian Reber <areber@xxxxxxxxxx>
---
 tools/testing/selftests/timens/Makefile |   4 +-
 tools/testing/selftests/timens/clone3.c | 134 ++++++++++++++++++++++++
 2 files changed, 136 insertions(+), 2 deletions(-)
 create mode 100644 tools/testing/selftests/timens/clone3.c

diff --git a/tools/testing/selftests/timens/Makefile b/tools/testing/selftests/timens/Makefile
index b4fd9a934654..4a50c326bdab 100644
--- a/tools/testing/selftests/timens/Makefile
+++ b/tools/testing/selftests/timens/Makefile
@@ -1,7 +1,7 @@
-TEST_GEN_PROGS := timens timerfd timer clock_nanosleep procfs exec
+TEST_GEN_PROGS := timens timerfd timer clock_nanosleep procfs exec clone3
 TEST_GEN_PROGS_EXTENDED := gettime_perf
 
-CFLAGS := -Wall -Werror -pthread
+CFLAGS := -Wall -Werror -pthread -I../../../../usr/include/
 LDLIBS := -lrt -ldl
 
 include ../lib.mk
diff --git a/tools/testing/selftests/timens/clone3.c b/tools/testing/selftests/timens/clone3.c
new file mode 100644
index 000000000000..212b35d43fa5
--- /dev/null
+++ b/tools/testing/selftests/timens/clone3.c
@@ -0,0 +1,134 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+#include <linux/sched.h>
+#include <linux/types.h>
+#include <sched.h>
+#include <stdint.h>
+#include <string.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "log.h"
+#include "timens.h"
+
+#define ptr_to_u64(ptr) ((__u64)((uintptr_t)(ptr)))
+
+struct set_timens_offset {
+	int clockid;
+	struct timespec val;
+};
+
+static void child_exit(int ret)
+{
+	fflush(stdout);
+	fflush(stderr);
+	_exit(ret);
+}
+
+static pid_t sys_clone3(struct clone_args *args, size_t size)
+{
+	fflush(stdout);
+	fflush(stderr);
+	return syscall(__NR_clone3, args, size);
+}
+
+int main(int argc, char *argv[])
+{
+	struct set_timens_offset timens_offset[2];
+	struct timespec monotonic;
+	struct timespec boottime;
+	pid_t pid = -1;
+	int ret = 0;
+	int status;
+
+	struct clone_args args = {
+		.flags = CLONE_NEWTIME,
+		.exit_signal = SIGCHLD,
+	};
+
+	nscheck();
+
+	ksft_set_plan(1);
+
+	ret = clock_gettime(CLOCK_MONOTONIC, &monotonic);
+	if (ret)
+		goto out;
+
+	ret = clock_gettime(CLOCK_BOOTTIME, &boottime);
+	if (ret)
+		goto out;
+
+	/* Set CLOCK_BOOTTIME to be 1 (sec). */
+	timens_offset[0].clockid = CLOCK_BOOTTIME;
+	timens_offset[0].val.tv_sec = -boottime.tv_sec + 1;
+	timens_offset[0].val.tv_nsec = 42;
+	/* Set CLOCK_MONOTONIC to be 10000 (sec) larger than current. */
+	timens_offset[1].clockid = CLOCK_MONOTONIC;
+	timens_offset[1].val.tv_sec = 10000;
+	timens_offset[1].val.tv_nsec = 37;
+
+	args.timens_offset_size = 2;
+	args.timens_offset = ptr_to_u64(timens_offset);
+
+	pid = sys_clone3(&args, sizeof(struct clone_args));
+	if (pid < 0) {
+		ksft_print_msg("%s - Failed to create new process\n",
+			       strerror(errno));
+		ret = -errno;
+		goto out;
+	}
+
+	if (pid == 0) {
+		struct timespec monotonic_in_ns;
+		struct timespec boottime_in_ns;
+
+		ksft_print_msg("I am the child, my PID is %d\n", getpid());
+		if (clock_gettime(CLOCK_MONOTONIC, &monotonic_in_ns))
+			return -1;
+
+		if (clock_gettime(CLOCK_BOOTTIME, &boottime_in_ns))
+			return -1;
+
+		/*
+		 * CLOCK_BOOTTIME has been set to such an offset to
+		 * be 1 in the time namespace after clone3().
+		 */
+		if (boottime_in_ns.tv_sec > 5)
+			child_exit(EXIT_FAILURE);
+		ksft_print_msg("CLOCK_BOOTTIME %ld\n", boottime_in_ns.tv_sec);
+		if (monotonic_in_ns.tv_sec <= monotonic.tv_sec + 9998)
+			child_exit(EXIT_FAILURE);
+		ksft_print_msg("CLOCK_MONOTONIC %ld\n", monotonic_in_ns.tv_sec);
+		child_exit(EXIT_SUCCESS);
+	}
+
+	if (waitpid(pid, &status, 0) < 0) {
+		ksft_print_msg("Child returned %s\n", strerror(errno));
+		ret = -errno;
+		goto out;
+	}
+
+	if (!WIFEXITED(status)) {
+		ret = -1;
+		ksft_test_result_fail("Child clocks in time NS are wrong\n");
+		goto out;
+	}
+
+	if (WEXITSTATUS(status)) {
+		ret = -1;
+		ksft_test_result_fail("Child clocks in time NS are wrong\n");
+		goto out;
+	}
+
+	ret = 0;
+	ksft_test_result_pass("Clocks set successfully with clone3()\n");
+out:
+	if (ret)
+		ksft_exit_fail();
+
+	ksft_exit_pass();
+	return !!ret;
+}
-- 
2.24.1