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DEFINITIONS
This source file includes following definitions.
- check_data
- check_bss
- check_sbrk
- main
1 /*
2 * Copyright (c) 2013
3 * The President and Fellows of Harvard College.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE UNIVERSITY OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30 /*
31 * zero - check that the VM system zeros pages given to processes
32 *
33 * This program will be much more likely to detect a problem if you
34 * run it *after* one of the out-of-core tests (huge, matmult, sort,
35 * etc.)
36 */
37
38 #include <stdio.h>
39 #include <unistd.h>
40 #include <errno.h>
41 #include <err.h>
42
43 /*
44 * Some initialized data. This is here to increase the chance that
45 * zeros[] spans page boundaries.
46 */
47 static unsigned data_stuff[] = {
48 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5,
49 2, 4, 6, 8, 0, 2, 4, 6, 8, 0, 2, 4, 6, 8, 0,
50 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5,
51 2, 4, 6, 8, 0, 2, 4, 6, 8, 0, 2, 4, 6, 8, 0,
52 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5,
53 2, 4, 6, 8, 0, 2, 4, 6, 8, 0, 2, 4, 6, 8, 0,
54 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5,
55 2, 4, 6, 8, 0, 2, 4, 6, 8, 0, 2, 4, 6, 8, 0,
56 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5,
57 2, 4, 6, 8, 0, 2, 4, 6, 8, 0, 2, 4, 6, 8, 0,
58 };
59
60 #define SUM_OF_DATA_STUFF 525
61
62 /*
63 * Some uninitialized (BSS, zero) data. Make it more than one page
64 * even if we happen to be on a machine with 8K pages.
65 */
66 static unsigned bss_stuff[3000];
67
68 static
69 void
70 check_data(void)
71 {
72 unsigned i, num, k;
73
74 num = sizeof(data_stuff) / sizeof(data_stuff[0]);
75 for (k=i=0; i<num; i++) {
76 k += data_stuff[i];
77 }
78 if (k != SUM_OF_DATA_STUFF) {
79 warnx("My initialized data sums to the wrong value!");
80 warnx("Got: %u Expected: %u", k, SUM_OF_DATA_STUFF);
81 errx(1, "FAILED");
82 }
83 }
84
85 static
86 void
87 check_bss(void)
88 {
89 unsigned i, num;
90
91 num = sizeof(bss_stuff) / sizeof(bss_stuff[0]);
92 for (i=0; i<num; i++) {
93 if (bss_stuff[i] != 0) {
94 warnx("BSS entry at index %u (address %p) not zero!",
95 i, &bss_stuff[i]);
96 warnx("Found: 0x%x", bss_stuff[i]);
97 errx(1, "FAILED");
98 }
99 }
100 }
101
102 static
103 void
104 check_sbrk(void)
105 {
106 char *base;
107 unsigned i;
108
109 /* get at least one page, even if the page size is 8K */
110 #define SBRK_SIZE 10000
111
112 base = sbrk(SBRK_SIZE);
113 if (base == (void *)-1) {
114 if (errno == EUNIMP) {
115 printf("I guess you haven't implemented sbrk yet.\n");
116 return;
117 }
118 err(1, "sbrk");
119 }
120
121 for (i=0; i<SBRK_SIZE; i++) {
122 if (base[i] != 0) {
123 warnx("Byte at offset %u (address %p) not zero",
124 i, &base[i]);
125 warnx("Got: 0x%x", (unsigned char)base[i]);
126 warnx("Base of sbrk region: %p", base);
127 errx(1, "FAILED");
128 }
129 }
130 }
131
132
133 int
134 main(void)
135 {
136 printf("zero: phase 1: checking .bss\n");
137 check_data();
138 check_bss();
139
140 printf("zero: phase 2: checking sbrk()\n");
141 check_sbrk();
142
143 printf("zero: passed\n");
144 return 0;
145 }