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 __FBSDID("$FreeBSD$"); 29 30 #include <sys/param.h> 31 #include <sys/systm.h> 32 #include <sys/kernel.h> 33 #include <sys/linker.h> 34 #include <sys/module.h> 35 #include <sys/malloc.h> 36 #include <sys/sysctl.h> 37 38 39 SYSCTL_NODE(_debug, OID_AUTO, redzone, CTLFLAG_RW, 0, ""); 40 41 #define REDZONE_MALLOC_UNDERFLOW 0 42 #define REDZONE_MALLOC_OVERFLOW 1 43 #define REDZONE_REALLOC_SMALLER_UNDERFLOW 2 44 #define REDZONE_REALLOC_SMALLER_OVERFLOW 3 45 #define REDZONE_REALLOC_BIGGER_UNDERFLOW 4 46 #define REDZONE_REALLOC_BIGGER_OVERFLOW 5 47 48 static int 49 redzone_sysctl(SYSCTL_HANDLER_ARGS) 50 { 51 u_char *p = NULL; 52 int error, val = 0; 53 54 error = sysctl_handle_int(oidp, &val, sizeof(val), req); 55 if (error != 0 || req->newptr == NULL) 56 return (0); 57 switch (arg2) { 58 case REDZONE_MALLOC_UNDERFLOW: 59 p = malloc(10, M_TEMP, M_NOWAIT); 60 if (p == NULL) 61 return (ENOMEM); 62 p[-1] = '\0'; 63 break; 64 case REDZONE_MALLOC_OVERFLOW: 65 p = malloc(10, M_TEMP, M_NOWAIT); 66 if (p == NULL) 67 return (ENOMEM); 68 p[10] = '\0'; 69 break; 70 case REDZONE_REALLOC_SMALLER_UNDERFLOW: 71 p = malloc(8192, M_TEMP, M_NOWAIT); 72 if (p == NULL) 73 return (ENOMEM); 74 p[-1] = '\0'; 75 p = realloc(p, 10, M_TEMP, M_NOWAIT); 76 if (p == NULL) 77 return (ENOMEM); 78 break; 79 case REDZONE_REALLOC_SMALLER_OVERFLOW: 80 p = malloc(8192, M_TEMP, M_NOWAIT); 81 if (p == NULL) 82 return (ENOMEM); 83 p[8192] = '\0'; 84 p = realloc(p, 10, M_TEMP, M_NOWAIT); 85 if (p == NULL) 86 return (ENOMEM); 87 break; 88 case REDZONE_REALLOC_BIGGER_UNDERFLOW: 89 p = malloc(10, M_TEMP, M_NOWAIT); 90 if (p == NULL) 91 return (ENOMEM); 92 p[-1] = '\0'; 93 p = realloc(p, 8192, M_TEMP, M_NOWAIT); 94 if (p == NULL) 95 return (ENOMEM); 96 break; 97 case REDZONE_REALLOC_BIGGER_OVERFLOW: 98 p = malloc(10, M_TEMP, M_NOWAIT); 99 if (p == NULL) 100 return (ENOMEM); 101 p[10] = '\0'; 102 p = realloc(p, 8192, M_TEMP, M_NOWAIT); 103 if (p == NULL) 104 return (ENOMEM); 105 break; 106 } 107 free(p, M_TEMP); 108 return (0); 109 } 110 SYSCTL_PROC(_debug_redzone, OID_AUTO, malloc_underflow, CTLTYPE_INT | CTLFLAG_RW, 111 NULL, REDZONE_MALLOC_UNDERFLOW, redzone_sysctl, "I", ""); 112 SYSCTL_PROC(_debug_redzone, OID_AUTO, malloc_overflow, CTLTYPE_INT | CTLFLAG_RW, 113 NULL, REDZONE_MALLOC_OVERFLOW, redzone_sysctl, "I", ""); 114 SYSCTL_PROC(_debug_redzone, OID_AUTO, realloc_smaller_underflow, CTLTYPE_INT | CTLFLAG_RW, 115 NULL, REDZONE_REALLOC_SMALLER_UNDERFLOW, redzone_sysctl, "I", ""); 116 SYSCTL_PROC(_debug_redzone, OID_AUTO, realloc_smaller_overflow, CTLTYPE_INT | CTLFLAG_RW, 117 NULL, REDZONE_REALLOC_SMALLER_OVERFLOW, redzone_sysctl, "I", ""); 118 SYSCTL_PROC(_debug_redzone, OID_AUTO, realloc_bigger_underflow, CTLTYPE_INT | CTLFLAG_RW, 119 NULL, REDZONE_REALLOC_BIGGER_UNDERFLOW, redzone_sysctl, "I", ""); 120 SYSCTL_PROC(_debug_redzone, OID_AUTO, realloc_bigger_overflow, CTLTYPE_INT | CTLFLAG_RW, 121 NULL, REDZONE_REALLOC_BIGGER_OVERFLOW, redzone_sysctl, "I", ""); 122 123 static int 124 redzone_modevent(module_t mod, int type, void *data) 125 { 126 127 switch (type) { 128 case MOD_LOAD: 129 case MOD_UNLOAD: 130 break; 131 default: 132 return (EOPNOTSUPP); 133 } 134 return (0); 135 } 136 static moduledata_t redzone_module = { 137 "redzone", 138 redzone_modevent, 139 NULL 140 }; 141 DECLARE_MODULE(redzone, redzone_module, SI_SUB_DRIVERS, SI_ORDER_MIDDLE); 142