// 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 <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 (labs(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 (labs(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 (labs(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;}