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/cdefs.h>
28 #include <sys/param.h>
29 #include <sys/systm.h>
30 #include <sys/kernel.h>
31 #include <sys/linker.h>
32 #include <sys/module.h>
33 #include <sys/malloc.h>
34 #include <sys/sysctl.h>
35
36
37 SYSCTL_NODE(_debug, OID_AUTO, redzone, CTLFLAG_RW, 0, "");
38
39 #define REDZONE_MALLOC_UNDERFLOW 0
40 #define REDZONE_MALLOC_OVERFLOW 1
41 #define REDZONE_REALLOC_SMALLER_UNDERFLOW 2
42 #define REDZONE_REALLOC_SMALLER_OVERFLOW 3
43 #define REDZONE_REALLOC_BIGGER_UNDERFLOW 4
44 #define REDZONE_REALLOC_BIGGER_OVERFLOW 5
45
46 static int
redzone_sysctl(SYSCTL_HANDLER_ARGS)47 redzone_sysctl(SYSCTL_HANDLER_ARGS)
48 {
49 u_char *p = NULL;
50 int error, val = 0;
51
52 error = sysctl_handle_int(oidp, &val, sizeof(val), req);
53 if (error != 0 || req->newptr == NULL)
54 return (0);
55 switch (arg2) {
56 case REDZONE_MALLOC_UNDERFLOW:
57 p = malloc(10, M_TEMP, M_NOWAIT);
58 if (p == NULL)
59 return (ENOMEM);
60 p[-1] = '\0';
61 break;
62 case REDZONE_MALLOC_OVERFLOW:
63 p = malloc(10, M_TEMP, M_NOWAIT);
64 if (p == NULL)
65 return (ENOMEM);
66 p[10] = '\0';
67 break;
68 case REDZONE_REALLOC_SMALLER_UNDERFLOW:
69 p = malloc(8192, M_TEMP, M_NOWAIT);
70 if (p == NULL)
71 return (ENOMEM);
72 p[-1] = '\0';
73 p = realloc(p, 10, M_TEMP, M_NOWAIT);
74 if (p == NULL)
75 return (ENOMEM);
76 break;
77 case REDZONE_REALLOC_SMALLER_OVERFLOW:
78 p = malloc(8192, M_TEMP, M_NOWAIT);
79 if (p == NULL)
80 return (ENOMEM);
81 p[8192] = '\0';
82 p = realloc(p, 10, M_TEMP, M_NOWAIT);
83 if (p == NULL)
84 return (ENOMEM);
85 break;
86 case REDZONE_REALLOC_BIGGER_UNDERFLOW:
87 p = malloc(10, M_TEMP, M_NOWAIT);
88 if (p == NULL)
89 return (ENOMEM);
90 p[-1] = '\0';
91 p = realloc(p, 8192, M_TEMP, M_NOWAIT);
92 if (p == NULL)
93 return (ENOMEM);
94 break;
95 case REDZONE_REALLOC_BIGGER_OVERFLOW:
96 p = malloc(10, M_TEMP, M_NOWAIT);
97 if (p == NULL)
98 return (ENOMEM);
99 p[10] = '\0';
100 p = realloc(p, 8192, M_TEMP, M_NOWAIT);
101 if (p == NULL)
102 return (ENOMEM);
103 break;
104 }
105 free(p, M_TEMP);
106 return (0);
107 }
108 SYSCTL_PROC(_debug_redzone, OID_AUTO, malloc_underflow, CTLTYPE_INT | CTLFLAG_RW,
109 NULL, REDZONE_MALLOC_UNDERFLOW, redzone_sysctl, "I", "");
110 SYSCTL_PROC(_debug_redzone, OID_AUTO, malloc_overflow, CTLTYPE_INT | CTLFLAG_RW,
111 NULL, REDZONE_MALLOC_OVERFLOW, redzone_sysctl, "I", "");
112 SYSCTL_PROC(_debug_redzone, OID_AUTO, realloc_smaller_underflow, CTLTYPE_INT | CTLFLAG_RW,
113 NULL, REDZONE_REALLOC_SMALLER_UNDERFLOW, redzone_sysctl, "I", "");
114 SYSCTL_PROC(_debug_redzone, OID_AUTO, realloc_smaller_overflow, CTLTYPE_INT | CTLFLAG_RW,
115 NULL, REDZONE_REALLOC_SMALLER_OVERFLOW, redzone_sysctl, "I", "");
116 SYSCTL_PROC(_debug_redzone, OID_AUTO, realloc_bigger_underflow, CTLTYPE_INT | CTLFLAG_RW,
117 NULL, REDZONE_REALLOC_BIGGER_UNDERFLOW, redzone_sysctl, "I", "");
118 SYSCTL_PROC(_debug_redzone, OID_AUTO, realloc_bigger_overflow, CTLTYPE_INT | CTLFLAG_RW,
119 NULL, REDZONE_REALLOC_BIGGER_OVERFLOW, redzone_sysctl, "I", "");
120
121 static int
redzone_modevent(module_t mod,int type,void * data)122 redzone_modevent(module_t mod, int type, void *data)
123 {
124
125 switch (type) {
126 case MOD_LOAD:
127 case MOD_UNLOAD:
128 break;
129 default:
130 return (EOPNOTSUPP);
131 }
132 return (0);
133 }
134 static moduledata_t redzone_module = {
135 "redzone",
136 redzone_modevent,
137 NULL
138 };
139 DECLARE_MODULE(redzone, redzone_module, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);
140