1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3  Copyright (c) 2020 Cyril Hrubis <chrubis@suse.cz>
4 */
5/*
6
7  Test if CLOCK_BOOTTIME namespace offset is applied to sysinfo uptime and that
8  it's consistent with /proc/uptime as well.
9
10  After a call to unshare(CLONE_NEWTIME) a new timer namespace is created, the
11  process that has called the unshare() can adjust offsets for CLOCK_MONOTONIC
12  and CLOCK_BOOTTIME for its children by writing to the '/proc/self/timens_offsets'.
13
14 */
15
16#include <sys/sysinfo.h>
17#include "lapi/posix_clocks.h"
18#include "tst_test.h"
19#include "lapi/sched.h"
20
21static int offsets[] = {
22	10,
23	-10,
24	3600,
25};
26
27static long read_proc_uptime(void)
28{
29	long sec, sec_rem;
30
31	SAFE_FILE_SCANF("/proc/uptime", "%li.%li", &sec, &sec_rem);
32
33	return sec + (sec_rem ? 1 : 0);
34}
35
36static void verify_sysinfo(unsigned int n)
37{
38	struct sysinfo si;
39	long uptime;
40	int off = offsets[n];
41
42	SAFE_UNSHARE(CLONE_NEWTIME);
43
44        SAFE_FILE_PRINTF("/proc/self/timens_offsets", "%d %d 0",
45	                 CLOCK_BOOTTIME, off);
46
47	sysinfo(&si);
48
49	uptime = si.uptime;
50
51	if (!SAFE_FORK()) {
52		sysinfo(&si);
53		long proc_uptime = read_proc_uptime();
54
55		long diff = si.uptime - uptime;
56
57		if (diff < off || diff > off + 1)
58			tst_res(TFAIL, "Wrong sysinfo uptime offset %li", diff);
59		else
60			tst_res(TPASS, "Correct sysinfo uptime offset %i", off);
61
62		if (si.uptime < proc_uptime || si.uptime > proc_uptime + 1) {
63			tst_res(TFAIL, "/proc/uptime %li differs from sysinfo %li",
64			        proc_uptime, si.uptime);
65		} else {
66			tst_res(TPASS, "/proc/uptime is consistent with sysinfo");
67		}
68	}
69}
70
71static struct tst_test test = {
72	.tcnt = ARRAY_SIZE(offsets),
73	.test = verify_sysinfo,
74	.needs_root = 1,
75	.forks_child = 1,
76	.needs_kconfigs = (const char *[]) {
77		"CONFIG_TIME_NS=y",
78		NULL
79	},
80	.tags = (const struct tst_tag[]) {
81		{"linux-git", "ecc421e05bab"},
82		{}
83	}
84};
85