1 /******************************************************************************
2  *
3  * Copyright FUJITSU LIMITED 2010
4  * Copyright KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
5  *
6  *   This program is free software;  you can redistribute it and/or modify
7  *   it under the terms of the GNU General Public License as published by
8  *   the Free Software Foundation; either version 2 of the License, or
9  *   (at your option) any later version.
10  *
11  * DESCRIPTION
12  *      Wait on uninitialized heap. It shold be zero and FUTEX_WAIT should
13  *      return immediately. This test is intent to test zero page handling in
14  *      futex.
15  *
16  * AUTHOR
17  *      KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
18  *
19  * HISTORY
20  *      2010-Jan-6: Initial version by KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
21  *
22  *****************************************************************************/
23 
24 #include <pthread.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <sys/mman.h>
28 #include <syscall.h>
29 #include <sys/types.h>
30 #include <sys/stat.h>
31 #include <unistd.h>
32 #include <errno.h>
33 #include <linux/futex.h>
34 #include <libgen.h>
35 
36 #include "logging.h"
37 #include "futextest.h"
38 
39 #define TEST_NAME "futex-wait-uninitialized-heap"
40 #define WAIT_US 5000000
41 
42 static int child_blocked = 1;
43 static int child_ret;
44 void *buf;
45 
46 void usage(char *prog)
47 {
48 	printf("Usage: %s\n", prog);
49 	printf("  -c	Use color\n");
50 	printf("  -h	Display this help message\n");
51 	printf("  -v L	Verbosity level: %d=QUIET %d=CRITICAL %d=INFO\n",
52 	       VQUIET, VCRITICAL, VINFO);
53 }
54 
55 void *wait_thread(void *arg)
56 {
57 	int res;
58 
59 	child_ret = RET_PASS;
60 	res = futex_wait(buf, 1, NULL, 0);
61 	child_blocked = 0;
62 
63 	if (res != 0 && errno != EWOULDBLOCK) {
64 		error("futex failure\n", errno);
65 		child_ret = RET_ERROR;
66 	}
67 	pthread_exit(NULL);
68 }
69 
70 int main(int argc, char **argv)
71 {
72 	int c, ret = RET_PASS;
73 	long page_size;
74 	pthread_t thr;
75 
76 	while ((c = getopt(argc, argv, "chv:")) != -1) {
77 		switch (c) {
78 		case 'c':
79 			log_color(1);
80 			break;
81 		case 'h':
82 			usage(basename(argv[0]));
83 			exit(0);
84 		case 'v':
85 			log_verbosity(atoi(optarg));
86 			break;
87 		default:
88 			usage(basename(argv[0]));
89 			exit(1);
90 		}
91 	}
92 
93 	page_size = sysconf(_SC_PAGESIZE);
94 
95 	buf = mmap(NULL, page_size, PROT_READ|PROT_WRITE,
96 		   MAP_PRIVATE|MAP_ANONYMOUS, 0, 0);
97 	if (buf == (void *)-1) {
98 		error("mmap\n", errno);
99 		exit(1);
100 	}
101 
102 	ksft_print_header();
103 	ksft_print_msg("%s: Test the uninitialized futex value in FUTEX_WAIT\n",
104 	       basename(argv[0]));
105 
106 
107 	ret = pthread_create(&thr, NULL, wait_thread, NULL);
108 	if (ret) {
109 		error("pthread_create\n", errno);
110 		ret = RET_ERROR;
111 		goto out;
112 	}
113 
114 	info("waiting %dus for child to return\n", WAIT_US);
115 	usleep(WAIT_US);
116 
117 	ret = child_ret;
118 	if (child_blocked) {
119 		fail("child blocked in kernel\n");
120 		ret = RET_FAIL;
121 	}
122 
123  out:
124 	print_result(TEST_NAME, ret);
125 	return ret;
126 }
127