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 static int child_ns, parent_ns;
  28
  29 static int switch_ns(int fd)
  30 {
  31         if (setns(fd, CLONE_NEWTIME))
  32                 return pr_perror("setns()");
  33
  34         return 0;
  35 }
  36
  37 static int init_namespaces(void)
  38 {
  39         char path[] = "/proc/self/ns/time_for_children";
  40         struct stat st1, st2;
  41
  42         parent_ns = open(path, O_RDONLY);
  43         if (parent_ns <= 0)
  44                 return pr_perror("Unable to open %s", path);
  45
  46         if (fstat(parent_ns, &st1))
  47                 return pr_perror("Unable to stat the parent timens");
  48
  49         if (unshare_timens())
  50                 return -1;
  51
  52         child_ns = open(path, O_RDONLY);
  53         if (child_ns <= 0)
  54                 return pr_perror("Unable to open %s", path);
  55
  56         if (fstat(child_ns, &st2))
  57                 return pr_perror("Unable to stat the timens");
  58
  59         if (st1.st_ino == st2.st_ino)
  60                 return pr_err("The same child_ns after CLONE_NEWTIME");
  61
  62         if (_settime(CLOCK_BOOTTIME, TEN_DAYS_IN_SEC))
  63                 return -1;
  64
  65         return 0;
  66 }
  67
  68 static int read_proc_uptime(struct timespec *uptime)
  69 {
  70         unsigned long up_sec, up_nsec;
  71         FILE *proc;
  72
  73         proc = fopen("/proc/uptime", "r");
  74         if (proc == NULL) {
  75                 pr_perror("Unable to open /proc/uptime");
  76                 return -1;
  77         }
  78
  79         if (fscanf(proc, "%lu.%02lu", &up_sec, &up_nsec) != 2) {
  80                 if (errno) {
  81                         pr_perror("fscanf");
  82                         return -errno;
  83                 }
  84                 pr_err("failed to parse /proc/uptime");
  85                 return -1;
  86         }
  87         fclose(proc);
  88
  89         uptime->tv_sec = up_sec;
  90         uptime->tv_nsec = up_nsec;
  91         return 0;
  92 }
  93
  94 static int read_proc_stat_btime(unsigned long long *boottime_sec)
  95 {
  96         FILE *proc;
  97         char line_buf[2048];
  98
  99         proc = fopen("/proc/stat", "r");
 100         if (proc == NULL) {
 101                 pr_perror("Unable to open /proc/stat");
 102                 return -1;
 103         }
 104
 105         while (fgets(line_buf, 2048, proc)) {
 106                 if (sscanf(line_buf, "btime %llu", boottime_sec) != 1)
 107                         continue;
 108                 fclose(proc);
 109                 return 0;
 110         }
 111         if (errno) {
 112                 pr_perror("fscanf");
 113                 fclose(proc);
 114                 return -errno;
 115         }
 116         pr_err("failed to parse /proc/stat");
 117         fclose(proc);
 118         return -1;
 119 }
 120
 121 static int check_uptime(void)
 122 {
 123         struct timespec uptime_new, uptime_old;
 124         time_t uptime_expected;
 125         double prec = MAX_TEST_TIME_SEC;
 126
 127         if (switch_ns(parent_ns))
 128                 return pr_err("switch_ns(%d)", parent_ns);
 129
 130         if (read_proc_uptime(&uptime_old))
 131                 return 1;
 132
 133         if (switch_ns(child_ns))
 134                 return pr_err("switch_ns(%d)", child_ns);
 135
 136         if (read_proc_uptime(&uptime_new))
 137                 return 1;
 138
 139         uptime_expected = uptime_old.tv_sec + TEN_DAYS_IN_SEC;
 140         if (fabs(difftime(uptime_new.tv_sec, uptime_expected)) > prec) {
 141                 pr_fail("uptime in /proc/uptime: old %ld, new %ld [%ld]",
 142                         uptime_old.tv_sec, uptime_new.tv_sec,
 143                         uptime_old.tv_sec + TEN_DAYS_IN_SEC);
 144                 return 1;
 145         }
 146
 147         ksft_test_result_pass("Passed for /proc/uptime\n");
 148         return 0;
 149 }
 150
 151 static int check_stat_btime(void)
 152 {
 153         unsigned long long btime_new, btime_old;
 154         unsigned long long btime_expected;
 155
 156         if (switch_ns(parent_ns))
 157                 return pr_err("switch_ns(%d)", parent_ns);
 158
 159         if (read_proc_stat_btime(&btime_old))
 160                 return 1;
 161
 162         if (switch_ns(child_ns))
 163                 return pr_err("switch_ns(%d)", child_ns);
 164
 165         if (read_proc_stat_btime(&btime_new))
 166                 return 1;
 167
 168         btime_expected = btime_old - TEN_DAYS_IN_SEC;
 169         if (btime_new != btime_expected) {
 170                 pr_fail("btime in /proc/stat: old %llu, new %llu [%llu]",
 171                         btime_old, btime_new, btime_expected);
 172                 return 1;
 173         }
 174
 175         ksft_test_result_pass("Passed for /proc/stat btime\n");
 176         return 0;
 177 }
 178
 179 int main(int argc, char *argv[])
 180 {
 181         int ret = 0;
 182
 183         nscheck();
 184
 185         ksft_set_plan(2);
 186
 187         if (init_namespaces())
 188                 return 1;
 189
 190         ret |= check_uptime();
 191         ret |= check_stat_btime();
 192
 193         if (ret)
 194                 ksft_exit_fail();
 195         ksft_exit_pass();
 196         return ret;
 197 }