1// SPDX-License-Identifier: GPL-2.0-or-later
2/******************************************************************************
3 *
4 *   Copyright �� International Business Machines  Corp., 2009
5 *
6 * DESCRIPTION
7 *      Block on a futex and wait for timeout.
8 *
9 * AUTHOR
10 *      Darren Hart <dvhart@linux.intel.com>
11 *
12 * HISTORY
13 *      2009-Nov-6: Initial version by Darren Hart <dvhart@linux.intel.com>
14 *      2021-Apr-26: More test cases by Andr�� Almeida <andrealmeid@collabora.com>
15 *
16 *****************************************************************************/
17
18#include <pthread.h>
19#include "futextest.h"
20#include "futex2test.h"
21#include "logging.h"
22
23#define TEST_NAME "futex-wait-timeout"
24
25static long timeout_ns = 100000;	/* 100us default timeout */
26static futex_t futex_pi;
27static pthread_barrier_t barrier;
28
29void usage(char *prog)
30{
31	printf("Usage: %s\n", prog);
32	printf("  -c	Use color\n");
33	printf("  -h	Display this help message\n");
34	printf("  -t N	Timeout in nanoseconds (default: 100,000)\n");
35	printf("  -v L	Verbosity level: %d=QUIET %d=CRITICAL %d=INFO\n",
36	       VQUIET, VCRITICAL, VINFO);
37}
38
39/*
40 * Get a PI lock and hold it forever, so the main thread lock_pi will block
41 * and we can test the timeout
42 */
43void *get_pi_lock(void *arg)
44{
45	int ret;
46	volatile futex_t lock = 0;
47
48	ret = futex_lock_pi(&futex_pi, NULL, 0, 0);
49	if (ret != 0)
50		error("futex_lock_pi failed\n", ret);
51
52	pthread_barrier_wait(&barrier);
53
54	/* Blocks forever */
55	ret = futex_wait(&lock, 0, NULL, 0);
56	error("futex_wait failed\n", ret);
57
58	return NULL;
59}
60
61/*
62 * Check if the function returned the expected error
63 */
64static void test_timeout(int res, int *ret, char *test_name, int err)
65{
66	if (!res || errno != err) {
67		ksft_test_result_fail("%s returned %d\n", test_name,
68				      res < 0 ? errno : res);
69		*ret = RET_FAIL;
70	} else {
71		ksft_test_result_pass("%s succeeds\n", test_name);
72	}
73}
74
75/*
76 * Calculate absolute timeout and correct overflow
77 */
78static int futex_get_abs_timeout(clockid_t clockid, struct timespec *to,
79				 long timeout_ns)
80{
81	if (clock_gettime(clockid, to)) {
82		error("clock_gettime failed\n", errno);
83		return errno;
84	}
85
86	to->tv_nsec += timeout_ns;
87
88	if (to->tv_nsec >= 1000000000) {
89		to->tv_sec++;
90		to->tv_nsec -= 1000000000;
91	}
92
93	return 0;
94}
95
96int main(int argc, char *argv[])
97{
98	futex_t f1 = FUTEX_INITIALIZER;
99	int res, ret = RET_PASS;
100	struct timespec to;
101	pthread_t thread;
102	int c;
103	struct futex_waitv waitv = {
104			.uaddr = (uintptr_t)&f1,
105			.val = f1,
106			.flags = FUTEX_32,
107			.__reserved = 0
108		};
109
110	while ((c = getopt(argc, argv, "cht:v:")) != -1) {
111		switch (c) {
112		case 'c':
113			log_color(1);
114			break;
115		case 'h':
116			usage(basename(argv[0]));
117			exit(0);
118		case 't':
119			timeout_ns = atoi(optarg);
120			break;
121		case 'v':
122			log_verbosity(atoi(optarg));
123			break;
124		default:
125			usage(basename(argv[0]));
126			exit(1);
127		}
128	}
129
130	ksft_print_header();
131	ksft_set_plan(9);
132	ksft_print_msg("%s: Block on a futex and wait for timeout\n",
133	       basename(argv[0]));
134	ksft_print_msg("\tArguments: timeout=%ldns\n", timeout_ns);
135
136	pthread_barrier_init(&barrier, NULL, 2);
137	pthread_create(&thread, NULL, get_pi_lock, NULL);
138
139	/* initialize relative timeout */
140	to.tv_sec = 0;
141	to.tv_nsec = timeout_ns;
142
143	res = futex_wait(&f1, f1, &to, 0);
144	test_timeout(res, &ret, "futex_wait relative", ETIMEDOUT);
145
146	/* FUTEX_WAIT_BITSET with CLOCK_REALTIME */
147	if (futex_get_abs_timeout(CLOCK_REALTIME, &to, timeout_ns))
148		return RET_FAIL;
149	res = futex_wait_bitset(&f1, f1, &to, 1, FUTEX_CLOCK_REALTIME);
150	test_timeout(res, &ret, "futex_wait_bitset realtime", ETIMEDOUT);
151
152	/* FUTEX_WAIT_BITSET with CLOCK_MONOTONIC */
153	if (futex_get_abs_timeout(CLOCK_MONOTONIC, &to, timeout_ns))
154		return RET_FAIL;
155	res = futex_wait_bitset(&f1, f1, &to, 1, 0);
156	test_timeout(res, &ret, "futex_wait_bitset monotonic", ETIMEDOUT);
157
158	/* FUTEX_WAIT_REQUEUE_PI with CLOCK_REALTIME */
159	if (futex_get_abs_timeout(CLOCK_REALTIME, &to, timeout_ns))
160		return RET_FAIL;
161	res = futex_wait_requeue_pi(&f1, f1, &futex_pi, &to, FUTEX_CLOCK_REALTIME);
162	test_timeout(res, &ret, "futex_wait_requeue_pi realtime", ETIMEDOUT);
163
164	/* FUTEX_WAIT_REQUEUE_PI with CLOCK_MONOTONIC */
165	if (futex_get_abs_timeout(CLOCK_MONOTONIC, &to, timeout_ns))
166		return RET_FAIL;
167	res = futex_wait_requeue_pi(&f1, f1, &futex_pi, &to, 0);
168	test_timeout(res, &ret, "futex_wait_requeue_pi monotonic", ETIMEDOUT);
169
170	/* Wait until the other thread calls futex_lock_pi() */
171	pthread_barrier_wait(&barrier);
172	pthread_barrier_destroy(&barrier);
173	/*
174	 * FUTEX_LOCK_PI with CLOCK_REALTIME
175	 * Due to historical reasons, FUTEX_LOCK_PI supports only realtime
176	 * clock, but requires the caller to not set CLOCK_REALTIME flag.
177	 *
178	 * If you call FUTEX_LOCK_PI with a monotonic clock, it'll be
179	 * interpreted as a realtime clock, and (unless you mess your machine's
180	 * time or your time machine) the monotonic clock value is always
181	 * smaller than realtime and the syscall will timeout immediately.
182	 */
183	if (futex_get_abs_timeout(CLOCK_REALTIME, &to, timeout_ns))
184		return RET_FAIL;
185	res = futex_lock_pi(&futex_pi, &to, 0, 0);
186	test_timeout(res, &ret, "futex_lock_pi realtime", ETIMEDOUT);
187
188	/* Test operations that don't support FUTEX_CLOCK_REALTIME */
189	res = futex_lock_pi(&futex_pi, NULL, 0, FUTEX_CLOCK_REALTIME);
190	test_timeout(res, &ret, "futex_lock_pi invalid timeout flag", ENOSYS);
191
192	/* futex_waitv with CLOCK_MONOTONIC */
193	if (futex_get_abs_timeout(CLOCK_MONOTONIC, &to, timeout_ns))
194		return RET_FAIL;
195	res = futex_waitv(&waitv, 1, 0, &to, CLOCK_MONOTONIC);
196	test_timeout(res, &ret, "futex_waitv monotonic", ETIMEDOUT);
197
198	/* futex_waitv with CLOCK_REALTIME */
199	if (futex_get_abs_timeout(CLOCK_REALTIME, &to, timeout_ns))
200		return RET_FAIL;
201	res = futex_waitv(&waitv, 1, 0, &to, CLOCK_REALTIME);
202	test_timeout(res, &ret, "futex_waitv realtime", ETIMEDOUT);
203
204	ksft_print_cnts();
205	return ret;
206}
207