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
27static int child_ns, parent_ns;
28
29static int switch_ns(int fd)
30{
31 if (setns(fd, CLONE_NEWTIME))
32 return pr_perror("setns()");
33
34 return 0;
35}
36
37static 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
68static 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
94static 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
121static 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(fd: parent_ns))
128 return pr_err("switch_ns(%d)", parent_ns);
129
130 if (read_proc_uptime(uptime: &uptime_old))
131 return 1;
132
133 if (switch_ns(fd: child_ns))
134 return pr_err("switch_ns(%d)", child_ns);
135
136 if (read_proc_uptime(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(msg: "Passed for /proc/uptime\n");
148 return 0;
149}
150
151static 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(fd: parent_ns))
157 return pr_err("switch_ns(%d)", parent_ns);
158
159 if (read_proc_stat_btime(boottime_sec: &btime_old))
160 return 1;
161
162 if (switch_ns(fd: child_ns))
163 return pr_err("switch_ns(%d)", child_ns);
164
165 if (read_proc_stat_btime(boottime_sec: &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(msg: "Passed for /proc/stat btime\n");
176 return 0;
177}
178
179int main(int argc, char *argv[])
180{
181 int ret = 0;
182
183 nscheck();
184
185 ksft_set_plan(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}
198

source code of linux/tools/testing/selftests/timens/procfs.c