1 /*
2  * Copyright (C) 2015 Cyril Hrubis <chrubis@suse.cz>
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms of version 2 of the GNU General Public License as
6  * published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it would be useful, but
9  * WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
11  *
12  * Further, this software is distributed without any warranty that it is
13  * free of the rightful claim of any third person regarding infringement
14  * or the like.  Any license provided herein, whether implied or
15  * otherwise, applies only to this software file.  Patent licenses, if
16  * any, provided herein do not apply to combinations of this program with
17  * other software, or any other product whatsoever.
18  *
19  * You should have received a copy of the GNU General Public License along
20  * with this program; if not, write the Free Software Foundation, Inc.,
21  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
22  */
23 
24 #include <stdint.h>
25 #include <limits.h>
26 #include <errno.h>
27 #include <sys/syscall.h>
28 #include <linux/futex.h>
29 
30 #include "test.h"
31 #include "safe_macros.h"
32 #include "lapi/futex.h"
33 
34 #define DEFAULT_MSEC_TIMEOUT 10000
35 
36 futex_t *tst_futexes;
37 unsigned int tst_max_futexes;
38 
tst_checkpoint_init(const char * file,const int lineno,void (* cleanup_fn)(void))39 void tst_checkpoint_init(const char *file, const int lineno,
40                          void (*cleanup_fn)(void))
41 {
42 	int fd;
43 	unsigned int page_size;
44 
45 	if (tst_futexes) {
46 		tst_brkm(TBROK, cleanup_fn,
47 		         "%s: %d checkopoints allready initialized",
48 		         file, lineno);
49 	}
50 
51 	/*
52 	 * The parent test process is responsible for creating the temporary
53 	 * directory and therefore must pass non-zero cleanup (to remove the
54 	 * directory if something went wrong).
55 	 *
56 	 * We cannot do this check unconditionally because if we need to init
57 	 * the checkpoint from a binary that was started by exec() the
58 	 * tst_tmpdir_created() will return false because the tmpdir was
59 	 * created by parent. In this case we expect the subprogram can call
60 	 * the init as a first function with NULL as cleanup function.
61 	 */
62 	if (cleanup_fn && !tst_tmpdir_created()) {
63 		tst_brkm(TBROK, cleanup_fn,
64 		         "%s:%d You have to create test temporary directory "
65 		         "first (call tst_tmpdir())", file, lineno);
66 	}
67 
68 	page_size = getpagesize();
69 
70 	fd = SAFE_OPEN(cleanup_fn, "checkpoint_futex_base_file",
71 	               O_RDWR | O_CREAT, 0666);
72 
73 	SAFE_FTRUNCATE(cleanup_fn, fd, page_size);
74 
75 	tst_futexes = SAFE_MMAP(cleanup_fn, NULL, page_size,
76 	                    PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
77 
78 	tst_max_futexes = page_size / sizeof(uint32_t);
79 
80 	SAFE_CLOSE(cleanup_fn, fd);
81 }
82 
tst_checkpoint_wait(unsigned int id,unsigned int msec_timeout)83 int tst_checkpoint_wait(unsigned int id, unsigned int msec_timeout)
84 {
85 	struct timespec timeout;
86 
87 	if (id >= tst_max_futexes) {
88 		errno = EOVERFLOW;
89 		return -1;
90 	}
91 
92 	timeout.tv_sec = msec_timeout/1000;
93 	timeout.tv_nsec = (msec_timeout%1000) * 1000000;
94 
95 	return syscall(SYS_futex, &tst_futexes[id], FUTEX_WAIT,
96 		       tst_futexes[id], &timeout);
97 }
98 
tst_checkpoint_wake(unsigned int id,unsigned int nr_wake,unsigned int msec_timeout)99 int tst_checkpoint_wake(unsigned int id, unsigned int nr_wake,
100                         unsigned int msec_timeout)
101 {
102 	unsigned int msecs = 0, waked = 0;
103 
104 	if (id >= tst_max_futexes) {
105 		errno = EOVERFLOW;
106 		return -1;
107 	}
108 
109 	for (;;) {
110 		waked += syscall(SYS_futex, &tst_futexes[id], FUTEX_WAKE,
111 				 INT_MAX, NULL);
112 
113 		if (waked == nr_wake)
114 			break;
115 
116 		usleep(1000);
117 		msecs++;
118 
119 		if (msecs >= msec_timeout) {
120 			errno = ETIMEDOUT;
121 			return -1;
122 		}
123 	}
124 
125 	return 0;
126 }
127 
tst_safe_checkpoint_wait(const char * file,const int lineno,void (* cleanup_fn)(void),unsigned int id)128 void tst_safe_checkpoint_wait(const char *file, const int lineno,
129                               void (*cleanup_fn)(void), unsigned int id)
130 {
131 	int ret = tst_checkpoint_wait(id, DEFAULT_MSEC_TIMEOUT);
132 
133 	if (ret) {
134 		tst_brkm(TBROK | TERRNO, cleanup_fn,
135 		         "%s:%d: tst_checkpoint_wait(%u, %i)",
136 		         file, lineno, id, DEFAULT_MSEC_TIMEOUT);
137 	}
138 }
139 
tst_safe_checkpoint_wake(const char * file,const int lineno,void (* cleanup_fn)(void),unsigned int id,unsigned int nr_wake)140 void tst_safe_checkpoint_wake(const char *file, const int lineno,
141                               void (*cleanup_fn)(void), unsigned int id,
142                               unsigned int nr_wake)
143 {
144 	int ret = tst_checkpoint_wake(id, nr_wake, DEFAULT_MSEC_TIMEOUT);
145 
146 	if (ret) {
147 		tst_brkm(TBROK | TERRNO, cleanup_fn,
148 		         "%s:%d: tst_checkpoint_wake(%u, %u, %i)",
149 		         file, lineno, id, nr_wake, DEFAULT_MSEC_TIMEOUT);
150 	}
151 }
152