1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3
4  Copyright (c) 2020 Cyril Hrubis <chrubis@suse.cz>
5
6 */
7/*
8
9  Basic test for timens_offsets error handling.
10
11  After a call to unshare(CLONE_NEWTIME) a new timer namespace is created, the
12  process that has called the unshare() can adjust offsets for CLOCK_MONOTONIC
13  and CLOCK_BOOTTIME for its children by writing to the '/proc/self/timens_offsets'.
14
15 */
16
17#define _GNU_SOURCE
18#include "lapi/posix_clocks.h"
19#include "tst_test.h"
20#include "lapi/sched.h"
21
22static struct tcase {
23	const char *desc;
24	const char *offsets;
25	int exp_err;
26} tcases[] = {
27	{"Obvious garbage", "not an offset", EINVAL},
28	{"Missing nanoseconds", "1 10", EINVAL},
29	{"Negative nanoseconds", "1 10 -10", EINVAL},
30	{"Nanoseconds > 1s", "1 10 1000000001", EINVAL},
31	{"Unsupported CLOCK_REALTIME", "0 10 0", EINVAL},
32	{"Mess on the second line", "1 10 0\na", EINVAL},
33	{"Overflow kernel 64bit ns timer", "1 9223372036 0", ERANGE},
34	{"Overflow kernel 64bit ns timer", "1 -9223372036 0", ERANGE},
35};
36
37static void verify_ns_clock(unsigned int n)
38{
39	struct tcase *tc = &tcases[n];
40	int fd, ret;
41
42	SAFE_UNSHARE(CLONE_NEWTIME);
43
44	fd = SAFE_OPEN("/proc/self/timens_offsets", O_WRONLY);
45	ret = write(fd, tc->offsets, strlen(tc->offsets));
46
47	if (ret != -1) {
48		tst_res(TFAIL, "%s returned %i", tc->desc, ret);
49		return;
50	}
51
52	if (errno != tc->exp_err) {
53		tst_res(TFAIL | TERRNO, "%s should fail with %s, got:",
54			tc->desc, tst_strerrno(tc->exp_err));
55		return;
56	}
57
58	tst_res(TPASS | TERRNO, "%s", tc->desc);
59}
60
61static struct tst_test test = {
62	.tcnt = ARRAY_SIZE(tcases),
63	.test = verify_ns_clock,
64	.needs_root = 1,
65	.needs_kconfigs = (const char *[]) {
66		"CONFIG_TIME_NS=y",
67		NULL
68	}
69};
70