1 /*-
2 * Copyright (c) 2006 Pawel Jakub Dawidek <pjd@FreeBSD.org>
3 * All rights reserved.
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 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27 #include <sys/param.h>
28 #include <sys/systm.h>
29 #include <sys/kernel.h>
30 #include <sys/linker.h>
31 #include <sys/module.h>
32 #include <sys/malloc.h>
33 #include <sys/sysctl.h>
34
35
36 SYSCTL_NODE(_debug, OID_AUTO, redzone, CTLFLAG_RW, 0, "");
37
38 #define REDZONE_MALLOC_UNDERFLOW 0
39 #define REDZONE_MALLOC_OVERFLOW 1
40 #define REDZONE_REALLOC_SMALLER_UNDERFLOW 2
41 #define REDZONE_REALLOC_SMALLER_OVERFLOW 3
42 #define REDZONE_REALLOC_BIGGER_UNDERFLOW 4
43 #define REDZONE_REALLOC_BIGGER_OVERFLOW 5
44
45 static int
redzone_sysctl(SYSCTL_HANDLER_ARGS)46 redzone_sysctl(SYSCTL_HANDLER_ARGS)
47 {
48 u_char *p = NULL;
49 int error, val = 0;
50
51 error = sysctl_handle_int(oidp, &val, sizeof(val), req);
52 if (error != 0 || req->newptr == NULL)
53 return (0);
54 switch (arg2) {
55 case REDZONE_MALLOC_UNDERFLOW:
56 p = malloc(10, M_TEMP, M_NOWAIT);
57 if (p == NULL)
58 return (ENOMEM);
59 p[-1] = '\0';
60 break;
61 case REDZONE_MALLOC_OVERFLOW:
62 p = malloc(10, M_TEMP, M_NOWAIT);
63 if (p == NULL)
64 return (ENOMEM);
65 p[10] = '\0';
66 break;
67 case REDZONE_REALLOC_SMALLER_UNDERFLOW:
68 p = malloc(8192, M_TEMP, M_NOWAIT);
69 if (p == NULL)
70 return (ENOMEM);
71 p[-1] = '\0';
72 p = realloc(p, 10, M_TEMP, M_NOWAIT);
73 if (p == NULL)
74 return (ENOMEM);
75 break;
76 case REDZONE_REALLOC_SMALLER_OVERFLOW:
77 p = malloc(8192, M_TEMP, M_NOWAIT);
78 if (p == NULL)
79 return (ENOMEM);
80 p[8192] = '\0';
81 p = realloc(p, 10, M_TEMP, M_NOWAIT);
82 if (p == NULL)
83 return (ENOMEM);
84 break;
85 case REDZONE_REALLOC_BIGGER_UNDERFLOW:
86 p = malloc(10, M_TEMP, M_NOWAIT);
87 if (p == NULL)
88 return (ENOMEM);
89 p[-1] = '\0';
90 p = realloc(p, 8192, M_TEMP, M_NOWAIT);
91 if (p == NULL)
92 return (ENOMEM);
93 break;
94 case REDZONE_REALLOC_BIGGER_OVERFLOW:
95 p = malloc(10, M_TEMP, M_NOWAIT);
96 if (p == NULL)
97 return (ENOMEM);
98 p[10] = '\0';
99 p = realloc(p, 8192, M_TEMP, M_NOWAIT);
100 if (p == NULL)
101 return (ENOMEM);
102 break;
103 }
104 free(p, M_TEMP);
105 return (0);
106 }
107 SYSCTL_PROC(_debug_redzone, OID_AUTO, malloc_underflow, CTLTYPE_INT | CTLFLAG_RW,
108 NULL, REDZONE_MALLOC_UNDERFLOW, redzone_sysctl, "I", "");
109 SYSCTL_PROC(_debug_redzone, OID_AUTO, malloc_overflow, CTLTYPE_INT | CTLFLAG_RW,
110 NULL, REDZONE_MALLOC_OVERFLOW, redzone_sysctl, "I", "");
111 SYSCTL_PROC(_debug_redzone, OID_AUTO, realloc_smaller_underflow, CTLTYPE_INT | CTLFLAG_RW,
112 NULL, REDZONE_REALLOC_SMALLER_UNDERFLOW, redzone_sysctl, "I", "");
113 SYSCTL_PROC(_debug_redzone, OID_AUTO, realloc_smaller_overflow, CTLTYPE_INT | CTLFLAG_RW,
114 NULL, REDZONE_REALLOC_SMALLER_OVERFLOW, redzone_sysctl, "I", "");
115 SYSCTL_PROC(_debug_redzone, OID_AUTO, realloc_bigger_underflow, CTLTYPE_INT | CTLFLAG_RW,
116 NULL, REDZONE_REALLOC_BIGGER_UNDERFLOW, redzone_sysctl, "I", "");
117 SYSCTL_PROC(_debug_redzone, OID_AUTO, realloc_bigger_overflow, CTLTYPE_INT | CTLFLAG_RW,
118 NULL, REDZONE_REALLOC_BIGGER_OVERFLOW, redzone_sysctl, "I", "");
119
120 static int
redzone_modevent(module_t mod,int type,void * data)121 redzone_modevent(module_t mod, int type, void *data)
122 {
123
124 switch (type) {
125 case MOD_LOAD:
126 case MOD_UNLOAD:
127 break;
128 default:
129 return (EOPNOTSUPP);
130 }
131 return (0);
132 }
133 static moduledata_t redzone_module = {
134 "redzone",
135 redzone_modevent,
136 NULL
137 };
138 DECLARE_MODULE(redzone, redzone_module, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);
139