1 /*
2 * Stack size mapping is decreased through mlock/munlock call.
3 *
4 * This is to test kernel if it has a problem with shortening [stack]
5 * mapping through several loops of mlock/munlock of /proc/self/maps.
6 *
7 * From:
8 * munlock 76KiB bfef2000-bff05000 rw-p 00000000 00:00 0 [stack]
9 *
10 * To:
11 * munlock 44KiB bfefa000-bff05000 rw-p 00000000 00:00 0 [stack]
12 *
13 * with more iterations - could drop to 0KiB.
14 *
15 * Copyright (C) 2010 Red Hat, Inc.
16 * This program is free software; you can redistribute it and/or
17 * modify it under the terms of version 2 of the GNU General Public
18 * License as published by the Free Software Foundation.
19 *
20 * This program is distributed in the hope that it would be useful,
21 * but WITHOUT ANY WARRANTY; without even the implied warranty of
22 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
23 *
24 * Further, this software is distributed without any warranty that it
25 * is free of the rightful claim of any third person regarding
26 * infringement or the like. Any license provided herein, whether
27 * implied or otherwise, applies only to this software file. Patent
28 * licenses, if any, provided herein do not apply to combinations of
29 * this program with other software, or any other product whatsoever.
30 *
31 * You should have received a copy of the GNU General Public License
32 * along with this program; if not, write the Free Software
33 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
34 * 02110-1301, USA.
35 */
36 #include <sys/mman.h>
37 #include <stdio.h>
38 #include <string.h>
39 #include "test.h"
40
41 #define KB 1024
42
43 char *TCID = "mlock03";
44 int TST_TOTAL = 1;
45
46 static void setup(void);
47 static void cleanup(void);
48
main(int argc,char * argv[])49 int main(int argc, char *argv[])
50 {
51 int lc;
52 long from, to;
53 long first = -1, last = -1;
54 char b[KB];
55 FILE *fp;
56
57 tst_parse_opts(argc, argv, NULL, NULL);
58
59 setup();
60
61 for (lc = 0; TEST_LOOPING(lc); lc++) {
62 fp = fopen("/proc/self/maps", "r");
63 if (fp == NULL)
64 tst_brkm(TBROK | TERRNO, cleanup, "fopen");
65 while (!feof(fp)) {
66 if (!fgets(b, KB - 1, fp))
67 break;
68 b[strlen(b) - 1] = '\0';
69 sscanf(b, "%lx-%lx", &from, &to);
70
71 /* Record the initial stack size. */
72 if (lc == 0 && strstr(b, "[stack]") != NULL)
73 first = (to - from) / KB;
74
75 switch (lc & 1) {
76 case 0:
77 if (mlock((const void *)from, to - from) == -1)
78 tst_resm(TINFO | TERRNO,
79 "mlock failed");
80 break;
81 case 1:
82 if (munlock((void *)from, to - from) == -1)
83 tst_resm(TINFO | TERRNO,
84 "munlock failed");
85 break;
86 default:
87 break;
88 }
89 tst_resm(TINFO, "%s from %lx to %0lx",
90 (lc & 1) ? "munlock" : "mlock", from, to);
91
92 /* Record the final stack size. */
93 if (strstr(b, "[stack]") != NULL)
94 last = (to - from) / KB;
95 }
96 fclose(fp);
97 }
98 tst_resm(TINFO, "starting stack size is %ld", first);
99 tst_resm(TINFO, "final stack size is %ld", last);
100 if (last < first)
101 tst_resm(TFAIL, "stack size is decreased.");
102 else
103 tst_resm(TPASS, "stack size is not decreased.");
104
105 cleanup();
106 tst_exit();
107 }
108
setup(void)109 void setup(void)
110 {
111 tst_require_root();
112
113 tst_sig(FORK, DEF_HANDLER, cleanup);
114 TEST_PAUSE;
115 }
116
cleanup(void)117 void cleanup(void)
118 {
119 }
120