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 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 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