LXR linux/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
  29static int child_ns, parent_ns;
  30
  31static int switch_ns(int fd)
  32{
  33        if (setns(fd, CLONE_NEWTIME))
  34                return pr_perror("setns()");
  35
  36        return 0;
  37}
  38
  39static 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
  70static 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
  96static 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
 126int 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}
 144