tools/testing/selftests/timens/futex.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #define _GNU_SOURCE
   3 #include <sched.h>
   4
   5 #include <linux/unistd.h>
   6 #include <linux/futex.h>
   7 #include <stdio.h>
   8 #include <string.h>
   9 #include <sys/syscall.h>
  10 #include <sys/types.h>
  11 #include <sys/wait.h>
  12 #include <time.h>
  13 #include <unistd.h>
  14
  15 #include "log.h"
  16 #include "timens.h"
  17
  18 #define NSEC_PER_SEC 1000000000ULL
  19
  20 static int run_test(int clockid)
  21 {
  22         int futex_op = FUTEX_WAIT_BITSET;
  23         struct timespec timeout, end;
  24         int val = 0;
  25
  26         if (clockid == CLOCK_REALTIME)
  27                 futex_op |= FUTEX_CLOCK_REALTIME;
  28
  29         clock_gettime(clockid, &timeout);
  30         timeout.tv_nsec += NSEC_PER_SEC / 10; // 100ms
  31         if (timeout.tv_nsec > NSEC_PER_SEC) {
  32                 timeout.tv_sec++;
  33                 timeout.tv_nsec -= NSEC_PER_SEC;
  34         }
  35
  36         if (syscall(__NR_futex, &val, futex_op, 0,
  37                     &timeout, 0, FUTEX_BITSET_MATCH_ANY) >= 0) {
  38                 ksft_test_result_fail("futex didn't return ETIMEDOUT\n");
  39                 return 1;
  40         }
  41
  42         if (errno != ETIMEDOUT) {
  43                 ksft_test_result_fail("futex didn't return ETIMEDOUT: %s\n",
  44                                                         strerror(errno));
  45                 return 1;
  46         }
  47
  48         clock_gettime(clockid, &end);
  49
  50         if (end.tv_sec < timeout.tv_sec ||
  51             (end.tv_sec == timeout.tv_sec && end.tv_nsec < timeout.tv_nsec)) {
  52                 ksft_test_result_fail("futex slept less than 100ms\n");
  53                 return 1;
  54         }
  55
  56
  57         ksft_test_result_pass("futex with the %d clockid\n", clockid);
  58
  59         return 0;
  60 }
  61
  62 int main(int argc, char *argv[])
  63 {
  64         int status, len, fd;
  65         char buf[4096];
  66         pid_t pid;
  67         struct timespec mtime_now;
  68
  69         nscheck();
  70
  71         ksft_set_plan(2);
  72
  73         clock_gettime(CLOCK_MONOTONIC, &mtime_now);
  74
  75         if (unshare_timens())
  76                 return 1;
  77
  78         len = snprintf(buf, sizeof(buf), "%d %d 0",
  79                         CLOCK_MONOTONIC, 70 * 24 * 3600);
  80         fd = open("/proc/self/timens_offsets", O_WRONLY);
  81         if (fd < 0)
  82                 return pr_perror("/proc/self/timens_offsets");
  83
  84         if (write(fd, buf, len) != len)
  85                 return pr_perror("/proc/self/timens_offsets");
  86
  87         close(fd);
  88
  89         pid = fork();
  90         if (pid < 0)
  91                 return pr_perror("Unable to fork");
  92         if (pid == 0) {
  93                 int ret = 0;
  94
  95                 ret |= run_test(CLOCK_REALTIME);
  96                 ret |= run_test(CLOCK_MONOTONIC);
  97                 if (ret)
  98                         ksft_exit_fail();
  99                 ksft_exit_pass();
 100                 return 0;
 101         }
 102
 103         if (waitpid(pid, &status, 0) != pid)
 104                 return pr_perror("Unable to wait the child process");
 105
 106         if (WIFEXITED(status))
 107                 return WEXITSTATUS(status);
 108
 109         return 1;
 110 }