tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1/* Make sure timers don't return early
2 * by: john stultz (johnstul@us.ibm.com)
3 * John Stultz (john.stultz@linaro.org)
4 * (C) Copyright IBM 2012
5 * (C) Copyright Linaro 2013 2015
6 * Licensed under the GPLv2
7 *
8 * To build:
9 * $ gcc nanosleep.c -o nanosleep -lrt
10 *
11 * This program is free software: you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation, either version 2 of the License, or
14 * (at your option) any later version.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
20 */
21
22#include <stdio.h>
23#include <stdlib.h>
24#include <time.h>
25#include <sys/time.h>
26#include <sys/timex.h>
27#include <string.h>
28#include <signal.h>
29#ifdef KTEST
30#include "../kselftest.h"
31#else
32static inline int ksft_exit_pass(void)
33{
34 exit(0);
35}
36static inline int ksft_exit_fail(void)
37{
38 exit(1);
39}
40#endif
41
42#define NSEC_PER_SEC 1000000000ULL
43
44#define CLOCK_REALTIME 0
45#define CLOCK_MONOTONIC 1
46#define CLOCK_PROCESS_CPUTIME_ID 2
47#define CLOCK_THREAD_CPUTIME_ID 3
48#define CLOCK_MONOTONIC_RAW 4
49#define CLOCK_REALTIME_COARSE 5
50#define CLOCK_MONOTONIC_COARSE 6
51#define CLOCK_BOOTTIME 7
52#define CLOCK_REALTIME_ALARM 8
53#define CLOCK_BOOTTIME_ALARM 9
54#define CLOCK_HWSPECIFIC 10
55#define CLOCK_TAI 11
56#define NR_CLOCKIDS 12
57
58#define UNSUPPORTED 0xf00f
59
60char *clockstring(int clockid)
61{
62 switch (clockid) {
63 case CLOCK_REALTIME:
64 return "CLOCK_REALTIME";
65 case CLOCK_MONOTONIC:
66 return "CLOCK_MONOTONIC";
67 case CLOCK_PROCESS_CPUTIME_ID:
68 return "CLOCK_PROCESS_CPUTIME_ID";
69 case CLOCK_THREAD_CPUTIME_ID:
70 return "CLOCK_THREAD_CPUTIME_ID";
71 case CLOCK_MONOTONIC_RAW:
72 return "CLOCK_MONOTONIC_RAW";
73 case CLOCK_REALTIME_COARSE:
74 return "CLOCK_REALTIME_COARSE";
75 case CLOCK_MONOTONIC_COARSE:
76 return "CLOCK_MONOTONIC_COARSE";
77 case CLOCK_BOOTTIME:
78 return "CLOCK_BOOTTIME";
79 case CLOCK_REALTIME_ALARM:
80 return "CLOCK_REALTIME_ALARM";
81 case CLOCK_BOOTTIME_ALARM:
82 return "CLOCK_BOOTTIME_ALARM";
83 case CLOCK_TAI:
84 return "CLOCK_TAI";
85 };
86 return "UNKNOWN_CLOCKID";
87}
88
89/* returns 1 if a <= b, 0 otherwise */
90static inline int in_order(struct timespec a, struct timespec b)
91{
92 if (a.tv_sec < b.tv_sec)
93 return 1;
94 if (a.tv_sec > b.tv_sec)
95 return 0;
96 if (a.tv_nsec > b.tv_nsec)
97 return 0;
98 return 1;
99}
100
101struct timespec timespec_add(struct timespec ts, unsigned long long ns)
102{
103 ts.tv_nsec += ns;
104 while (ts.tv_nsec >= NSEC_PER_SEC) {
105 ts.tv_nsec -= NSEC_PER_SEC;
106 ts.tv_sec++;
107 }
108 return ts;
109}
110
111int nanosleep_test(int clockid, long long ns)
112{
113 struct timespec now, target, rel;
114
115 /* First check abs time */
116 if (clock_gettime(clockid, &now))
117 return UNSUPPORTED;
118 target = timespec_add(now, ns);
119
120 if (clock_nanosleep(clockid, TIMER_ABSTIME, &target, NULL))
121 return UNSUPPORTED;
122 clock_gettime(clockid, &now);
123
124 if (!in_order(target, now))
125 return -1;
126
127 /* Second check reltime */
128 clock_gettime(clockid, &now);
129 rel.tv_sec = 0;
130 rel.tv_nsec = 0;
131 rel = timespec_add(rel, ns);
132 target = timespec_add(now, ns);
133 clock_nanosleep(clockid, 0, &rel, NULL);
134 clock_gettime(clockid, &now);
135
136 if (!in_order(target, now))
137 return -1;
138 return 0;
139}
140
141int main(int argc, char **argv)
142{
143 long long length;
144 int clockid, ret;
145
146 for (clockid = CLOCK_REALTIME; clockid < NR_CLOCKIDS; clockid++) {
147
148 /* Skip cputime clockids since nanosleep won't increment cputime */
149 if (clockid == CLOCK_PROCESS_CPUTIME_ID ||
150 clockid == CLOCK_THREAD_CPUTIME_ID ||
151 clockid == CLOCK_HWSPECIFIC)
152 continue;
153
154 printf("Nanosleep %-31s ", clockstring(clockid));
155
156 length = 10;
157 while (length <= (NSEC_PER_SEC * 10)) {
158 ret = nanosleep_test(clockid, length);
159 if (ret == UNSUPPORTED) {
160 printf("[UNSUPPORTED]\n");
161 goto next;
162 }
163 if (ret < 0) {
164 printf("[FAILED]\n");
165 return ksft_exit_fail();
166 }
167 length *= 100;
168 }
169 printf("[OK]\n");
170next:
171 ret = 0;
172 }
173 return ksft_exit_pass();
174}