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 "logging.h"
33 #include "futextest.h"
34 
35 #define TEST_NAME "futex-wait-uninitialized-heap"
36 #define WAIT_US 5000000
37 
38 static int child_blocked = 1;
39 static int child_ret;
40 void *buf;
41 
42 void usage(char *prog)
43 {
44 	printf("Usage: %s\n", prog);
45 	printf("  -c	Use color\n");
46 	printf("  -h	Display this help message\n");
47 	printf("  -v L	Verbosity level: %d=QUIET %d=CRITICAL %d=INFO\n",
48 	       VQUIET, VCRITICAL, VINFO);
49 }
50 
51 void *wait_thread(void *arg)
52 {
53 	int res;
54 
55 	child_ret = RET_PASS;
56 	res = futex_wait(buf, 1, NULL, 0);
57 	child_blocked = 0;
58 
59 	if (res != 0 && errno != EWOULDBLOCK) {
60 		error("futex failure\n", errno);
61 		child_ret = RET_ERROR;
62 	}
63 	pthread_exit(NULL);
64 }
65 
66 int main(int argc, char **argv)
67 {
68 	int c, ret = RET_PASS;
69 	long page_size;
70 	pthread_t thr;
71 
72 	while ((c = getopt(argc, argv, "chv:")) != -1) {
73 		switch (c) {
74 		case 'c':
75 			log_color(1);
76 			break;
77 		case 'h':
78 			usage(basename(argv[0]));
79 			exit(0);
80 		case 'v':
81 			log_verbosity(atoi(optarg));
82 			break;
83 		default:
84 			usage(basename(argv[0]));
85 			exit(1);
86 		}
87 	}
88 
89 	page_size = sysconf(_SC_PAGESIZE);
90 
91 	buf = mmap(NULL, page_size, PROT_READ|PROT_WRITE,
92 		   MAP_PRIVATE|MAP_ANONYMOUS, 0, 0);
93 	if (buf == (void *)-1) {
94 		error("mmap\n", errno);
95 		exit(1);
96 	}
97 
98 	ksft_print_header();
99 	ksft_set_plan(1);
100 	ksft_print_msg("%s: Test the uninitialized futex value in FUTEX_WAIT\n",
101 	       basename(argv[0]));
102 
103 
104 	ret = pthread_create(&thr, NULL, wait_thread, NULL);
105 	if (ret) {
106 		error("pthread_create\n", errno);
107 		ret = RET_ERROR;
108 		goto out;
109 	}
110 
111 	info("waiting %dus for child to return\n", WAIT_US);
112 	usleep(WAIT_US);
113 
114 	ret = child_ret;
115 	if (child_blocked) {
116 		fail("child blocked in kernel\n");
117 		ret = RET_FAIL;
118 	}
119 
120  out:
121 	print_result(TEST_NAME, ret);
122 	return ret;
123 }
124