1 /*- 2 * Copyright (c) 2002, 2003, 2004, 2005 Jeffrey Roberson <jeff@FreeBSD.org> 3 * Copyright (c) 2004, 2005 Bosko Milekic <bmilekic@FreeBSD.org> 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice unmodified, this list of conditions, and the following 11 * disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 /* 29 * uma_dbg.c Debugging features for UMA users 30 * 31 */ 32 33 #include <sys/cdefs.h> 34 __FBSDID("$FreeBSD$"); 35 36 #include <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/bitset.h> 39 #include <sys/kernel.h> 40 #include <sys/types.h> 41 #include <sys/queue.h> 42 #include <sys/lock.h> 43 #include <sys/mutex.h> 44 #include <sys/malloc.h> 45 46 #include <vm/vm.h> 47 #include <vm/vm_object.h> 48 #include <vm/vm_page.h> 49 #include <vm/uma.h> 50 #include <vm/uma_int.h> 51 #include <vm/uma_dbg.h> 52 53 static const uint32_t uma_junk = 0xdeadc0de; 54 55 /* 56 * Checks an item to make sure it hasn't been overwritten since it was freed, 57 * prior to subsequent reallocation. 58 * 59 * Complies with standard ctor arg/return 60 * 61 */ 62 int 63 trash_ctor(void *mem, int size, void *arg, int flags) 64 { 65 int cnt; 66 uint32_t *p; 67 68 cnt = size / sizeof(uma_junk); 69 70 for (p = mem; cnt > 0; cnt--, p++) 71 if (*p != uma_junk) { 72 printf("Memory modified after free %p(%d) val=%x @ %p\n", 73 mem, size, *p, p); 74 return (0); 75 } 76 return (0); 77 } 78 79 /* 80 * Fills an item with predictable garbage 81 * 82 * Complies with standard dtor arg/return 83 * 84 */ 85 void 86 trash_dtor(void *mem, int size, void *arg) 87 { 88 int cnt; 89 uint32_t *p; 90 91 cnt = size / sizeof(uma_junk); 92 93 for (p = mem; cnt > 0; cnt--, p++) 94 *p = uma_junk; 95 } 96 97 /* 98 * Fills an item with predictable garbage 99 * 100 * Complies with standard init arg/return 101 * 102 */ 103 int 104 trash_init(void *mem, int size, int flags) 105 { 106 trash_dtor(mem, size, NULL); 107 return (0); 108 } 109 110 /* 111 * Checks an item to make sure it hasn't been overwritten since it was freed. 112 * 113 * Complies with standard fini arg/return 114 * 115 */ 116 void 117 trash_fini(void *mem, int size) 118 { 119 (void)trash_ctor(mem, size, NULL, 0); 120 } 121 122 int 123 mtrash_ctor(void *mem, int size, void *arg, int flags) 124 { 125 struct malloc_type **ksp; 126 uint32_t *p = mem; 127 int cnt; 128 129 size -= sizeof(struct malloc_type *); 130 ksp = (struct malloc_type **)mem; 131 ksp += size / sizeof(struct malloc_type *); 132 cnt = size / sizeof(uma_junk); 133 134 for (p = mem; cnt > 0; cnt--, p++) 135 if (*p != uma_junk) { 136 printf("Memory modified after free %p(%d) val=%x @ %p\n", 137 mem, size, *p, p); 138 panic("Most recently used by %s\n", (*ksp == NULL)? 139 "none" : (*ksp)->ks_shortdesc); 140 } 141 return (0); 142 } 143 144 /* 145 * Fills an item with predictable garbage 146 * 147 * Complies with standard dtor arg/return 148 * 149 */ 150 void 151 mtrash_dtor(void *mem, int size, void *arg) 152 { 153 int cnt; 154 uint32_t *p; 155 156 size -= sizeof(struct malloc_type *); 157 cnt = size / sizeof(uma_junk); 158 159 for (p = mem; cnt > 0; cnt--, p++) 160 *p = uma_junk; 161 } 162 163 /* 164 * Fills an item with predictable garbage 165 * 166 * Complies with standard init arg/return 167 * 168 */ 169 int 170 mtrash_init(void *mem, int size, int flags) 171 { 172 struct malloc_type **ksp; 173 174 mtrash_dtor(mem, size, NULL); 175 176 ksp = (struct malloc_type **)mem; 177 ksp += (size / sizeof(struct malloc_type *)) - 1; 178 *ksp = NULL; 179 return (0); 180 } 181 182 /* 183 * Checks an item to make sure it hasn't been overwritten since it was freed, 184 * prior to freeing it back to available memory. 185 * 186 * Complies with standard fini arg/return 187 * 188 */ 189 void 190 mtrash_fini(void *mem, int size) 191 { 192 (void)mtrash_ctor(mem, size, NULL, 0); 193 } 194 195 #ifdef INVARIANTS 196 static uma_slab_t 197 uma_dbg_getslab(uma_zone_t zone, void *item) 198 { 199 uma_slab_t slab; 200 uma_keg_t keg; 201 uint8_t *mem; 202 203 mem = (uint8_t *)((uintptr_t)item & (~UMA_SLAB_MASK)); 204 if (zone->uz_flags & UMA_ZONE_VTOSLAB) { 205 slab = vtoslab((vm_offset_t)mem); 206 } else { 207 /* 208 * It is safe to return the slab here even though the 209 * zone is unlocked because the item's allocation state 210 * essentially holds a reference. 211 */ 212 ZONE_LOCK(zone); 213 keg = LIST_FIRST(&zone->uz_kegs)->kl_keg; 214 if (keg->uk_flags & UMA_ZONE_HASH) 215 slab = hash_sfind(&keg->uk_hash, mem); 216 else 217 slab = (uma_slab_t)(mem + keg->uk_pgoff); 218 ZONE_UNLOCK(zone); 219 } 220 221 return (slab); 222 } 223 224 /* 225 * Set up the slab's freei data such that uma_dbg_free can function. 226 * 227 */ 228 void 229 uma_dbg_alloc(uma_zone_t zone, uma_slab_t slab, void *item) 230 { 231 uma_keg_t keg; 232 int freei; 233 234 if (zone_first_keg(zone) == NULL) 235 return; 236 if (slab == NULL) { 237 slab = uma_dbg_getslab(zone, item); 238 if (slab == NULL) 239 panic("uma: item %p did not belong to zone %s\n", 240 item, zone->uz_name); 241 } 242 keg = slab->us_keg; 243 freei = ((uintptr_t)item - (uintptr_t)slab->us_data) / keg->uk_rsize; 244 245 if (BIT_ISSET(SLAB_SETSIZE, freei, &slab->us_debugfree)) 246 panic("Duplicate alloc of %p from zone %p(%s) slab %p(%d)\n", 247 item, zone, zone->uz_name, slab, freei); 248 BIT_SET_ATOMIC(SLAB_SETSIZE, freei, &slab->us_debugfree); 249 250 return; 251 } 252 253 /* 254 * Verifies freed addresses. Checks for alignment, valid slab membership 255 * and duplicate frees. 256 * 257 */ 258 void 259 uma_dbg_free(uma_zone_t zone, uma_slab_t slab, void *item) 260 { 261 uma_keg_t keg; 262 int freei; 263 264 if (zone_first_keg(zone) == NULL) 265 return; 266 if (slab == NULL) { 267 slab = uma_dbg_getslab(zone, item); 268 if (slab == NULL) 269 panic("uma: Freed item %p did not belong to zone %s\n", 270 item, zone->uz_name); 271 } 272 keg = slab->us_keg; 273 freei = ((uintptr_t)item - (uintptr_t)slab->us_data) / keg->uk_rsize; 274 275 if (freei >= keg->uk_ipers) 276 panic("Invalid free of %p from zone %p(%s) slab %p(%d)\n", 277 item, zone, zone->uz_name, slab, freei); 278 279 if (((freei * keg->uk_rsize) + slab->us_data) != item) 280 panic("Unaligned free of %p from zone %p(%s) slab %p(%d)\n", 281 item, zone, zone->uz_name, slab, freei); 282 283 if (!BIT_ISSET(SLAB_SETSIZE, freei, &slab->us_debugfree)) 284 panic("Duplicate free of %p from zone %p(%s) slab %p(%d)\n", 285 item, zone, zone->uz_name, slab, freei); 286 287 BIT_CLR_ATOMIC(SLAB_SETSIZE, freei, &slab->us_debugfree); 288 } 289 290 #endif /* INVARIANTS */ 291