1 /* $NetBSD: subr_debug.c,v 1.5 2007/11/14 11:06:53 yamt Exp $ */ 2 3 /*- 4 * Copyright (c) 2007 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Andrew Doran. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 /* 40 * Shared support code for kernels built with the DEBUG option. 41 */ 42 43 #include <sys/cdefs.h> 44 __KERNEL_RCSID(0, "$NetBSD: subr_debug.c,v 1.5 2007/11/14 11:06:53 yamt Exp $"); 45 46 #include "opt_ddb.h" 47 48 #include <sys/param.h> 49 #include <sys/proc.h> 50 #include <sys/systm.h> 51 #include <sys/kmem.h> 52 #include <sys/debug.h> 53 54 #include <uvm/uvm_extern.h> 55 56 #include <machine/lock.h> 57 #include <sys/cpu.h> 58 59 /* 60 * Allocation/free validation by pointer address. Introduces 61 * significant overhead and is not enabled by default. Patch 62 * `debug_freecheck' to 1 at boot time to enable. 63 */ 64 #define FREECHECK_BYTES (8*1024*1024) 65 66 typedef struct fcitem { 67 void *i_addr; 68 struct fcitem *i_next; 69 } fcitem_t; 70 71 fcitem_t *freecheck_free; 72 __cpu_simple_lock_t freecheck_lock; 73 int debug_freecheck; 74 75 void 76 debug_init(void) 77 { 78 size_t cnt; 79 fcitem_t *i; 80 81 __cpu_simple_lock_init(&freecheck_lock); 82 83 if (debug_freecheck) { 84 i = (fcitem_t *)uvm_km_alloc(kernel_map, FREECHECK_BYTES, 0, 85 UVM_KMF_WIRED); 86 if (i == NULL) { 87 printf("freecheck_init: unable to allocate memory"); 88 return; 89 } 90 91 for (cnt = FREECHECK_BYTES / sizeof(*i); cnt != 0; cnt--) { 92 i->i_next = freecheck_free; 93 freecheck_free = i++; 94 } 95 } 96 } 97 98 void 99 freecheck_out(void **head, void *addr) 100 { 101 fcitem_t *i; 102 int s; 103 104 if (!debug_freecheck) 105 return; 106 107 s = splvm(); 108 __cpu_simple_lock(&freecheck_lock); 109 for (i = *head; i != NULL; i = i->i_next) { 110 if (i->i_addr != addr) 111 continue; 112 __cpu_simple_unlock(&freecheck_lock); 113 splx(s); 114 panic("freecheck_out: %p already out", addr); 115 } 116 if ((i = freecheck_free) != NULL) { 117 freecheck_free = i->i_next; 118 i->i_addr = addr; 119 i->i_next = *head; 120 *head = i; 121 } 122 __cpu_simple_unlock(&freecheck_lock); 123 splx(s); 124 125 if (i == NULL) { 126 printf("freecheck_out: no more slots\n"); 127 debug_freecheck = 0; 128 } 129 } 130 131 void 132 freecheck_in(void **head, void *addr) 133 { 134 fcitem_t *i; 135 void *pp; 136 int s; 137 138 if (!debug_freecheck) 139 return; 140 141 s = splvm(); 142 __cpu_simple_lock(&freecheck_lock); 143 for (i = *head, pp = head; i != NULL; pp = &i->i_next, i = i->i_next) { 144 if (i->i_addr == addr) { 145 *(fcitem_t **)pp = i->i_next; 146 i->i_next = freecheck_free; 147 freecheck_free = i; 148 break; 149 } 150 } 151 __cpu_simple_unlock(&freecheck_lock); 152 splx(s); 153 154 if (i != NULL) 155 return; 156 157 #ifdef DDB 158 printf("freecheck_in: %p not out\n", addr); 159 Debugger(); 160 #else 161 panic("freecheck_in: %p not out", addr); 162 #endif 163 } 164