// SPDX-License-Identifier: GPL-2.0
#define _GNU_SOURCE
#include <sched.h>

#include <linux/unistd.h>
#include <linux/futex.h>
#include <stdio.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 NSEC_PER_SEC 1000000000ULL

static int run_test(int clockid)
{
        int futex_op = FUTEX_WAIT_BITSET;
        struct timespec timeout, end;
        int val = 0;

        if (clockid == CLOCK_REALTIME)
                futex_op |= FUTEX_CLOCK_REALTIME;

        clock_gettime(clockid, &timeout);
        timeout.tv_nsec += NSEC_PER_SEC / 10; // 100ms
        if (timeout.tv_nsec > NSEC_PER_SEC) {
                timeout.tv_sec++;
                timeout.tv_nsec -= NSEC_PER_SEC;
        }

        if (syscall(__NR_futex, &val, futex_op, 0,
                    &timeout, 0, FUTEX_BITSET_MATCH_ANY) >= 0) {
                ksft_test_result_fail("futex didn't return ETIMEDOUT\n");
                return 1;
        }

        if (errno != ETIMEDOUT) {
                ksft_test_result_fail("futex didn't return ETIMEDOUT: %s\n",
                                                        strerror(errno));
                return 1;
        }

        clock_gettime(clockid, &end);

        if (end.tv_sec < timeout.tv_sec ||
            (end.tv_sec == timeout.tv_sec && end.tv_nsec < timeout.tv_nsec)) {
                ksft_test_result_fail("futex slept less than 100ms\n");
                return 1;
        }


        ksft_test_result_pass("futex with the %d clockid\n", clockid);

        return 0;
}

int main(int argc, char *argv[])
{
        int status, len, fd;
        char buf[4096];
        pid_t pid;
        struct timespec mtime_now;

        ksft_print_header();

        nscheck();

        ksft_set_plan(2);

        clock_gettime(CLOCK_MONOTONIC, &mtime_now);

        if (unshare_timens())
                return 1;

        len = snprintf(buf, sizeof(buf), "%d %d 0",
                        CLOCK_MONOTONIC, 70 * 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);

        pid = fork();
        if (pid < 0)
                return pr_perror("Unable to fork");
        if (pid == 0) {
                int ret = 0;

                ret |= run_test(CLOCK_REALTIME);
                ret |= run_test(CLOCK_MONOTONIC);
                if (ret)
                        ksft_exit_fail();
                ksft_exit_pass();
                return 0;
        }

        if (waitpid(pid, &status, 0) != pid)
                return pr_perror("Unable to wait the child process");

        if (WIFEXITED(status))
                return WEXITSTATUS(status);

        return 1;
}