xref: /linux/tools/testing/selftests/futex/functional/futex_wait_uninitialized_heap.c (revision c574fb2ed7c96f87fc0e5295e910e646a7ee4dfa)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /******************************************************************************
3  *
4  * Copyright FUJITSU LIMITED 2010
5  * Copyright KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
6  *
7  * DESCRIPTION
8  *      Wait on uninitialized heap. It shold be zero and FUTEX_WAIT should
9  *      return immediately. This test is intent to test zero page handling in
10  *      futex.
11  *
12  * AUTHOR
13  *      KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
14  *
15  * HISTORY
16  *      2010-Jan-6: Initial version by KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
17  *
18  *****************************************************************************/
19 
20 #include <pthread.h>
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <sys/mman.h>
24 #include <syscall.h>
25 #include <sys/types.h>
26 #include <sys/stat.h>
27 #include <unistd.h>
28 #include <errno.h>
29 #include <linux/futex.h>
30 #include <libgen.h>
31 
32 #include "futextest.h"
33 #include "../../kselftest_harness.h"
34 
35 #define WAIT_US 5000000
36 
37 static int child_blocked = 1;
38 static bool child_ret;
39 void *buf;
40 
wait_thread(void * arg)41 void *wait_thread(void *arg)
42 {
43 	int res;
44 
45 	child_ret = true;
46 	res = futex_wait(buf, 1, NULL, 0);
47 	child_blocked = 0;
48 
49 	if (res != 0 && errno != EWOULDBLOCK) {
50 		ksft_exit_fail_msg("futex failure\n");
51 		child_ret = false;
52 	}
53 	pthread_exit(NULL);
54 }
55 
TEST(futex_wait_uninitialized_heap)56 TEST(futex_wait_uninitialized_heap)
57 {
58 	long page_size;
59 	pthread_t thr;
60 	int ret;
61 
62 	page_size = sysconf(_SC_PAGESIZE);
63 
64 	buf = mmap(NULL, page_size, PROT_READ|PROT_WRITE,
65 		   MAP_PRIVATE|MAP_ANONYMOUS, 0, 0);
66 	if (buf == (void *)-1)
67 		ksft_exit_fail_msg("mmap\n");
68 
69 	ret = pthread_create(&thr, NULL, wait_thread, NULL);
70 	if (ret)
71 		ksft_exit_fail_msg("pthread_create\n");
72 
73 	ksft_print_dbg_msg("waiting %dus for child to return\n", WAIT_US);
74 	usleep(WAIT_US);
75 
76 	if (child_blocked)
77 		ksft_test_result_fail("child blocked in kernel\n");
78 
79 	if (!child_ret)
80 		ksft_test_result_fail("child error\n");
81 }
82 
83 TEST_HARNESS_MAIN
84