futex_wait.c

  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
 20void *futex;
 21
 22static 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
 39TEST(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
 65TEST(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
103TEST(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
146TEST_HARNESS_MAIN