futex_wait_uninitialized_heap.c

 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
37static int child_blocked = 1;
38static bool child_ret;
39void *buf;
40
41void *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
56TEST(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
83TEST_HARNESS_MAIN