xref: /linux/tools/testing/selftests/futex/functional/futex_wait.c (revision 0048fbb4011ec55c32d3148b2cda56433f273375)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright Collabora Ltd., 2021
4  *
5  * futex cmp requeue test by André Almeida <andrealmeid@collabora.com>
6  */
7 
8 #include <pthread.h>
9 #include <sys/shm.h>
10 #include <sys/mman.h>
11 #include <fcntl.h>
12 
13 #include "futextest.h"
14 #include "kselftest_harness.h"
15 
16 #define timeout_ns  30000000
17 #define WAKE_WAIT_US 10000
18 #define SHM_PATH "futex_shm_file"
19 
20 void *futex;
21 
waiterfn(void * arg)22 static void *waiterfn(void *arg)
23 {
24 	struct timespec to;
25 	unsigned int flags = 0;
26 
27 	if (arg)
28 		flags = *((unsigned int *) arg);
29 
30 	to.tv_sec = 0;
31 	to.tv_nsec = timeout_ns;
32 
33 	if (futex_wait(futex, 0, &to, flags))
34 		printf("waiter failed errno %d\n", errno);
35 
36 	return NULL;
37 }
38 
TEST(private_futex)39 TEST(private_futex)
40 {
41 	unsigned int flags = FUTEX_PRIVATE_FLAG;
42 	u_int32_t f_private = 0;
43 	pthread_t waiter;
44 	int res;
45 
46 	futex = &f_private;
47 
48 	/* Testing a private futex */
49 	ksft_print_dbg_msg("Calling private futex_wait on futex: %p\n", futex);
50 	if (pthread_create(&waiter, NULL, waiterfn, (void *) &flags))
51 		ksft_exit_fail_msg("pthread_create failed\n");
52 
53 	usleep(WAKE_WAIT_US);
54 
55 	ksft_print_dbg_msg("Calling private futex_wake on futex: %p\n", futex);
56 	res = futex_wake(futex, 1, FUTEX_PRIVATE_FLAG);
57 	if (res != 1) {
58 		ksft_test_result_fail("futex_wake private returned: %d %s\n",
59 				      errno, strerror(errno));
60 	} else {
61 		ksft_test_result_pass("futex_wake private succeeds\n");
62 	}
63 }
64 
TEST(anon_page)65 TEST(anon_page)
66 {
67 	u_int32_t *shared_data;
68 	pthread_t waiter;
69 	int res, shm_id;
70 
71 	/* Testing an anon page shared memory */
72 	shm_id = shmget(IPC_PRIVATE, 4096, IPC_CREAT | 0666);
73 	if (shm_id < 0) {
74 		if (errno == ENOSYS)
75 			ksft_exit_skip("shmget syscall not supported\n");
76 		perror("shmget");
77 		exit(1);
78 	}
79 
80 	shared_data = shmat(shm_id, NULL, 0);
81 
82 	*shared_data = 0;
83 	futex = shared_data;
84 
85 	ksft_print_dbg_msg("Calling shared (page anon) futex_wait on futex: %p\n", futex);
86 	if (pthread_create(&waiter, NULL, waiterfn, NULL))
87 		ksft_exit_fail_msg("pthread_create failed\n");
88 
89 	usleep(WAKE_WAIT_US);
90 
91 	ksft_print_dbg_msg("Calling shared (page anon) futex_wake on futex: %p\n", futex);
92 	res = futex_wake(futex, 1, 0);
93 	if (res != 1) {
94 		ksft_test_result_fail("futex_wake shared (page anon) returned: %d %s\n",
95 				      errno, strerror(errno));
96 	} else {
97 		ksft_test_result_pass("futex_wake shared (page anon) succeeds\n");
98 	}
99 
100 	shmdt(shared_data);
101 }
102 
TEST(file_backed)103 TEST(file_backed)
104 {
105 	u_int32_t f_private = 0;
106 	pthread_t waiter;
107 	int res, fd;
108 	void *shm;
109 
110 	/* Testing a file backed shared memory */
111 	fd = open(SHM_PATH, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR);
112 	if (fd < 0)
113 		ksft_exit_fail_msg("open\n");
114 
115 	if (ftruncate(fd, sizeof(f_private)))
116 		ksft_exit_fail_msg("ftruncate\n");
117 
118 	shm = mmap(NULL, sizeof(f_private), PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
119 	if (shm == MAP_FAILED)
120 		ksft_exit_fail_msg("mmap\n");
121 
122 	memcpy(shm, &f_private, sizeof(f_private));
123 
124 	futex = shm;
125 
126 	ksft_print_dbg_msg("Calling shared (file backed) futex_wait on futex: %p\n", futex);
127 	if (pthread_create(&waiter, NULL, waiterfn, NULL))
128 		ksft_exit_fail_msg("pthread_create failed\n");
129 
130 	usleep(WAKE_WAIT_US);
131 
132 	ksft_print_dbg_msg("Calling shared (file backed) futex_wake on futex: %p\n", futex);
133 	res = futex_wake(shm, 1, 0);
134 	if (res != 1) {
135 		ksft_test_result_fail("futex_wake shared (file backed) returned: %d %s\n",
136 				      errno, strerror(errno));
137 	} else {
138 		ksft_test_result_pass("futex_wake shared (file backed) succeeds\n");
139 	}
140 
141 	munmap(shm, sizeof(f_private));
142 	remove(SHM_PATH);
143 	close(fd);
144 }
145 
146 TEST_HARNESS_MAIN
147