tools/testing/selftests/timens/procfs.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #define _GNU_SOURCE
   3 #include <errno.h>
   4 #include <fcntl.h>
   5 #include <math.h>
   6 #include <sched.h>
   7 #include <stdio.h>
   8 #include <stdbool.h>
   9 #include <stdlib.h>
  10 #include <sys/stat.h>
  11 #include <sys/syscall.h>
  12 #include <sys/types.h>
  13 #include <time.h>
  14 #include <unistd.h>
  15
  16 #include "log.h"
  17 #include "timens.h"
  18
  19 /*
  20  * Test shouldn't be run for a day, so add 10 days to child
  21  * time and check parent's time to be in the same day.
  22  */
  23 #define MAX_TEST_TIME_SEC               (60*5)
  24 #define DAY_IN_SEC                      (60*60*24)
  25 #define TEN_DAYS_IN_SEC                 (10*DAY_IN_SEC)
  26
  27 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
  28
  29 static int child_ns, parent_ns;
  30
  31 static int switch_ns(int fd)
  32 {
  33         if (setns(fd, CLONE_NEWTIME))
  34                 return pr_perror("setns()");
  35
  36         return 0;
  37 }
  38
  39 static int init_namespaces(void)
  40 {
  41         char path[] = "/proc/self/ns/time_for_children";
  42         struct stat st1, st2;
  43
  44         parent_ns = open(path, O_RDONLY);
  45         if (parent_ns <= 0)
  46                 return pr_perror("Unable to open %s", path);
  47
  48         if (fstat(parent_ns, &st1))
  49                 return pr_perror("Unable to stat the parent timens");
  50
  51         if (unshare_timens())
  52                 return -1;
  53
  54         child_ns = open(path, O_RDONLY);
  55         if (child_ns <= 0)
  56                 return pr_perror("Unable to open %s", path);
  57
  58         if (fstat(child_ns, &st2))
  59                 return pr_perror("Unable to stat the timens");
  60
  61         if (st1.st_ino == st2.st_ino)
  62                 return pr_err("The same child_ns after CLONE_NEWTIME");
  63
  64         if (_settime(CLOCK_BOOTTIME, TEN_DAYS_IN_SEC))
  65                 return -1;
  66
  67         return 0;
  68 }
  69
  70 static int read_proc_uptime(struct timespec *uptime)
  71 {
  72         unsigned long up_sec, up_nsec;
  73         FILE *proc;
  74
  75         proc = fopen("/proc/uptime", "r");
  76         if (proc == NULL) {
  77                 pr_perror("Unable to open /proc/uptime");
  78                 return -1;
  79         }
  80
  81         if (fscanf(proc, "%lu.%02lu", &up_sec, &up_nsec) != 2) {
  82                 if (errno) {
  83                         pr_perror("fscanf");
  84                         return -errno;
  85                 }
  86                 pr_err("failed to parse /proc/uptime");
  87                 return -1;
  88         }
  89         fclose(proc);
  90
  91         uptime->tv_sec = up_sec;
  92         uptime->tv_nsec = up_nsec;
  93         return 0;
  94 }
  95
  96 static int check_uptime(void)
  97 {
  98         struct timespec uptime_new, uptime_old;
  99         time_t uptime_expected;
 100         double prec = MAX_TEST_TIME_SEC;
 101
 102         if (switch_ns(parent_ns))
 103                 return pr_err("switch_ns(%d)", parent_ns);
 104
 105         if (read_proc_uptime(&uptime_old))
 106                 return 1;
 107
 108         if (switch_ns(child_ns))
 109                 return pr_err("switch_ns(%d)", child_ns);
 110
 111         if (read_proc_uptime(&uptime_new))
 112                 return 1;
 113
 114         uptime_expected = uptime_old.tv_sec + TEN_DAYS_IN_SEC;
 115         if (fabs(difftime(uptime_new.tv_sec, uptime_expected)) > prec) {
 116                 pr_fail("uptime in /proc/uptime: old %ld, new %ld [%ld]",
 117                         uptime_old.tv_sec, uptime_new.tv_sec,
 118                         uptime_old.tv_sec + TEN_DAYS_IN_SEC);
 119                 return 1;
 120         }
 121
 122         ksft_test_result_pass("Passed for /proc/uptime\n");
 123         return 0;
 124 }
 125
 126 int main(int argc, char *argv[])
 127 {
 128         int ret = 0;
 129
 130         nscheck();
 131
 132         ksft_set_plan(1);
 133
 134         if (init_namespaces())
 135                 return 1;
 136
 137         ret |= check_uptime();
 138
 139         if (ret)
 140                 ksft_exit_fail();
 141         ksft_exit_pass();
 142         return ret;
 143 }