subr_kmem.c revision 1.53
1 /* $NetBSD: subr_kmem.c,v 1.53 2014/06/23 17:43:42 maxv Exp $ */ 2 3 /*- 4 * Copyright (c) 2009 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 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 /*- 33 * Copyright (c)2006 YAMAMOTO Takashi, 34 * All rights reserved. 35 * 36 * Redistribution and use in source and binary forms, with or without 37 * modification, are permitted provided that the following conditions 38 * are met: 39 * 1. Redistributions of source code must retain the above copyright 40 * notice, this list of conditions and the following disclaimer. 41 * 2. Redistributions in binary form must reproduce the above copyright 42 * notice, this list of conditions and the following disclaimer in the 43 * documentation and/or other materials provided with the distribution. 44 * 45 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 46 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 47 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 48 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 49 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 50 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 51 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 52 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 53 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 54 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 55 * SUCH DAMAGE. 56 */ 57 58 /* 59 * Allocator of kernel wired memory. 60 */ 61 62 /* 63 * This allocator has some debug features enabled with "option DEBUG" and 64 * "option DIAGNOSTIC". 65 * 66 * KMEM_POISON 67 * Try to detect modify-after-free bugs. 68 * 69 * Fill freed (in the sense of kmem_free) memory with a garbage pattern. 70 * Check the pattern on allocation. 71 * 72 * KMEM_REDZONE 73 * Try to detect overrun bugs. 74 * 75 * Allocate some more bytes for each allocation. 76 * The extra bytes are checked by KMEM_POISON on kmem_free. 77 * 78 * KMEM_SIZE 79 * Try to detect alloc/free size mismatch bugs. 80 * 81 * Prefix each allocations with a fixed-sized header and record 82 * the exact user-requested allocation size in it. 83 * When freeing, compare it with kmem_free's "size" argument. 84 * 85 * KMEM_GUARD 86 * See the below "kmguard" section. 87 */ 88 89 /* 90 * kmguard 91 * 92 * A kernel with "option DEBUG" has "kmguard" debugging feature compiled in. 93 * See the comment in uvm/uvm_kmguard.c for what kind of bugs it tries to 94 * detect. Even if compiled in, it's disabled by default because it's very 95 * expensive. You can enable it on boot by: 96 * 97 * boot -d 98 * db> w kmem_guard_depth 0t30000 99 * db> c 100 * 101 * The default value of kmem_guard_depth is 0, which means disabled. 102 * It can be changed by KMEM_GUARD_DEPTH kernel config option. 103 */ 104 105 #include <sys/cdefs.h> 106 __KERNEL_RCSID(0, "$NetBSD: subr_kmem.c,v 1.53 2014/06/23 17:43:42 maxv Exp $"); 107 108 #include <sys/param.h> 109 #include <sys/callback.h> 110 #include <sys/kmem.h> 111 #include <sys/pool.h> 112 #include <sys/debug.h> 113 #include <sys/lockdebug.h> 114 #include <sys/cpu.h> 115 116 #include <uvm/uvm_extern.h> 117 #include <uvm/uvm_map.h> 118 #include <uvm/uvm_kmguard.h> 119 120 #include <lib/libkern/libkern.h> 121 122 struct kmem_cache_info { 123 size_t kc_size; 124 const char * kc_name; 125 }; 126 127 static const struct kmem_cache_info kmem_cache_sizes[] = { 128 { 8, "kmem-8" }, 129 { 16, "kmem-16" }, 130 { 24, "kmem-24" }, 131 { 32, "kmem-32" }, 132 { 40, "kmem-40" }, 133 { 48, "kmem-48" }, 134 { 56, "kmem-56" }, 135 { 64, "kmem-64" }, 136 { 80, "kmem-80" }, 137 { 96, "kmem-96" }, 138 { 112, "kmem-112" }, 139 { 128, "kmem-128" }, 140 { 160, "kmem-160" }, 141 { 192, "kmem-192" }, 142 { 224, "kmem-224" }, 143 { 256, "kmem-256" }, 144 { 320, "kmem-320" }, 145 { 384, "kmem-384" }, 146 { 448, "kmem-448" }, 147 { 512, "kmem-512" }, 148 { 768, "kmem-768" }, 149 { 1024, "kmem-1024" }, 150 { 0, NULL } 151 }; 152 153 static const struct kmem_cache_info kmem_cache_big_sizes[] = { 154 { 2048, "kmem-2048" }, 155 { 4096, "kmem-4096" }, 156 { 8192, "kmem-8192" }, 157 { 16384, "kmem-16384" }, 158 { 0, NULL } 159 }; 160 161 /* 162 * KMEM_ALIGN is the smallest guaranteed alignment and also the 163 * smallest allocateable quantum. 164 * Every cache size >= CACHE_LINE_SIZE gets CACHE_LINE_SIZE alignment. 165 */ 166 #define KMEM_ALIGN 8 167 #define KMEM_SHIFT 3 168 #define KMEM_MAXSIZE 1024 169 #define KMEM_CACHE_COUNT (KMEM_MAXSIZE >> KMEM_SHIFT) 170 171 static pool_cache_t kmem_cache[KMEM_CACHE_COUNT] __cacheline_aligned; 172 static size_t kmem_cache_maxidx __read_mostly; 173 174 #define KMEM_BIG_ALIGN 2048 175 #define KMEM_BIG_SHIFT 11 176 #define KMEM_BIG_MAXSIZE 16384 177 #define KMEM_CACHE_BIG_COUNT (KMEM_BIG_MAXSIZE >> KMEM_BIG_SHIFT) 178 179 static pool_cache_t kmem_cache_big[KMEM_CACHE_BIG_COUNT] __cacheline_aligned; 180 static size_t kmem_cache_big_maxidx __read_mostly; 181 182 #if defined(DIAGNOSTIC) && defined(_HARDKERNEL) 183 #define KMEM_SIZE 184 #endif /* defined(DIAGNOSTIC) */ 185 186 #if defined(DEBUG) && defined(_HARDKERNEL) 187 #define KMEM_POISON 188 #define KMEM_REDZONE 189 #define KMEM_GUARD 190 #endif /* defined(DEBUG) */ 191 192 #if defined(KMEM_POISON) 193 static int kmem_poison_ctor(void *, void *, int); 194 static void kmem_poison_fill(void *, size_t); 195 static void kmem_poison_check(void *, size_t); 196 #else /* defined(KMEM_POISON) */ 197 #define kmem_poison_fill(p, sz) /* nothing */ 198 #define kmem_poison_check(p, sz) /* nothing */ 199 #endif /* defined(KMEM_POISON) */ 200 201 #if defined(KMEM_REDZONE) 202 #define REDZONE_SIZE 1 203 #else /* defined(KMEM_REDZONE) */ 204 #define REDZONE_SIZE 0 205 #endif /* defined(KMEM_REDZONE) */ 206 207 #if defined(KMEM_SIZE) 208 #define SIZE_SIZE (MAX(KMEM_ALIGN, sizeof(size_t))) 209 static void kmem_size_set(void *, size_t); 210 static void kmem_size_check(void *, size_t); 211 #else 212 #define SIZE_SIZE 0 213 #define kmem_size_set(p, sz) /* nothing */ 214 #define kmem_size_check(p, sz) /* nothing */ 215 #endif 216 217 #if defined(KMEM_GUARD) 218 #ifndef KMEM_GUARD_DEPTH 219 #define KMEM_GUARD_DEPTH 0 220 #endif 221 int kmem_guard_depth = KMEM_GUARD_DEPTH; 222 size_t kmem_guard_size; 223 static struct uvm_kmguard kmem_guard; 224 static void *kmem_freecheck; 225 #endif /* defined(KMEM_GUARD) */ 226 227 CTASSERT(KM_SLEEP == PR_WAITOK); 228 CTASSERT(KM_NOSLEEP == PR_NOWAIT); 229 230 /* 231 * kmem_intr_alloc: allocate wired memory. 232 */ 233 234 void * 235 kmem_intr_alloc(size_t requested_size, km_flag_t kmflags) 236 { 237 size_t allocsz, index; 238 size_t size; 239 pool_cache_t pc; 240 uint8_t *p; 241 242 KASSERT(requested_size > 0); 243 244 #ifdef KMEM_GUARD 245 if (requested_size <= kmem_guard_size) { 246 return uvm_kmguard_alloc(&kmem_guard, requested_size, 247 (kmflags & KM_SLEEP) != 0); 248 } 249 #endif 250 size = kmem_roundup_size(requested_size); 251 allocsz = size + REDZONE_SIZE + SIZE_SIZE; 252 253 if ((index = ((allocsz -1) >> KMEM_SHIFT)) 254 < kmem_cache_maxidx) { 255 pc = kmem_cache[index]; 256 } else if ((index = ((allocsz - 1) >> KMEM_BIG_SHIFT)) 257 < kmem_cache_big_maxidx) { 258 pc = kmem_cache_big[index]; 259 } else { 260 int ret = uvm_km_kmem_alloc(kmem_va_arena, 261 (vsize_t)round_page(size), 262 ((kmflags & KM_SLEEP) ? VM_SLEEP : VM_NOSLEEP) 263 | VM_INSTANTFIT, (vmem_addr_t *)&p); 264 if (ret) { 265 return NULL; 266 } 267 FREECHECK_OUT(&kmem_freecheck, p); 268 return p; 269 } 270 271 p = pool_cache_get(pc, kmflags); 272 273 if (__predict_true(p != NULL)) { 274 kmem_poison_check(p, size); 275 FREECHECK_OUT(&kmem_freecheck, p); 276 kmem_size_set(p, requested_size); 277 278 return p + SIZE_SIZE; 279 } 280 return p; 281 } 282 283 /* 284 * kmem_intr_zalloc: allocate zeroed wired memory. 285 */ 286 287 void * 288 kmem_intr_zalloc(size_t size, km_flag_t kmflags) 289 { 290 void *p; 291 292 p = kmem_intr_alloc(size, kmflags); 293 if (p != NULL) { 294 memset(p, 0, size); 295 } 296 return p; 297 } 298 299 /* 300 * kmem_intr_free: free wired memory allocated by kmem_alloc. 301 */ 302 303 void 304 kmem_intr_free(void *p, size_t requested_size) 305 { 306 size_t allocsz, index; 307 size_t size; 308 pool_cache_t pc; 309 310 KASSERT(p != NULL); 311 KASSERT(requested_size > 0); 312 313 #ifdef KMEM_GUARD 314 if (requested_size <= kmem_guard_size) { 315 uvm_kmguard_free(&kmem_guard, requested_size, p); 316 return; 317 } 318 #endif 319 size = kmem_roundup_size(requested_size); 320 allocsz = size + REDZONE_SIZE + SIZE_SIZE; 321 322 if ((index = ((allocsz -1) >> KMEM_SHIFT)) 323 < kmem_cache_maxidx) { 324 pc = kmem_cache[index]; 325 } else if ((index = ((allocsz - 1) >> KMEM_BIG_SHIFT)) 326 < kmem_cache_big_maxidx) { 327 pc = kmem_cache_big[index]; 328 } else { 329 FREECHECK_IN(&kmem_freecheck, p); 330 uvm_km_kmem_free(kmem_va_arena, (vaddr_t)p, 331 round_page(size)); 332 return; 333 } 334 335 p = (uint8_t *)p - SIZE_SIZE; 336 kmem_size_check(p, requested_size); 337 FREECHECK_IN(&kmem_freecheck, p); 338 LOCKDEBUG_MEM_CHECK(p, size); 339 kmem_poison_check((uint8_t *)p + SIZE_SIZE + size, 340 allocsz - (SIZE_SIZE + size)); 341 kmem_poison_fill(p, allocsz); 342 343 pool_cache_put(pc, p); 344 } 345 346 /* ---- kmem API */ 347 348 /* 349 * kmem_alloc: allocate wired memory. 350 * => must not be called from interrupt context. 351 */ 352 353 void * 354 kmem_alloc(size_t size, km_flag_t kmflags) 355 { 356 357 KASSERTMSG((!cpu_intr_p() && !cpu_softintr_p()), 358 "kmem(9) should not be used from the interrupt context"); 359 return kmem_intr_alloc(size, kmflags); 360 } 361 362 /* 363 * kmem_zalloc: allocate zeroed wired memory. 364 * => must not be called from interrupt context. 365 */ 366 367 void * 368 kmem_zalloc(size_t size, km_flag_t kmflags) 369 { 370 371 KASSERTMSG((!cpu_intr_p() && !cpu_softintr_p()), 372 "kmem(9) should not be used from the interrupt context"); 373 return kmem_intr_zalloc(size, kmflags); 374 } 375 376 /* 377 * kmem_free: free wired memory allocated by kmem_alloc. 378 * => must not be called from interrupt context. 379 */ 380 381 void 382 kmem_free(void *p, size_t size) 383 { 384 385 KASSERT(!cpu_intr_p()); 386 KASSERT(!cpu_softintr_p()); 387 kmem_intr_free(p, size); 388 } 389 390 static size_t 391 kmem_create_caches(const struct kmem_cache_info *array, 392 pool_cache_t alloc_table[], size_t maxsize, int shift, int ipl) 393 { 394 size_t maxidx = 0; 395 size_t table_unit = (1 << shift); 396 size_t size = table_unit; 397 int i; 398 399 for (i = 0; array[i].kc_size != 0 ; i++) { 400 const char *name = array[i].kc_name; 401 size_t cache_size = array[i].kc_size; 402 struct pool_allocator *pa; 403 int flags = PR_NOALIGN; 404 pool_cache_t pc; 405 size_t align; 406 407 if ((cache_size & (CACHE_LINE_SIZE - 1)) == 0) 408 align = CACHE_LINE_SIZE; 409 else if ((cache_size & (PAGE_SIZE - 1)) == 0) 410 align = PAGE_SIZE; 411 else 412 align = KMEM_ALIGN; 413 414 if (cache_size < CACHE_LINE_SIZE) 415 flags |= PR_NOTOUCH; 416 417 /* check if we reached the requested size */ 418 if (cache_size > maxsize || cache_size > PAGE_SIZE) { 419 break; 420 } 421 if ((cache_size >> shift) > maxidx) { 422 maxidx = cache_size >> shift; 423 } 424 425 if ((cache_size >> shift) > maxidx) { 426 maxidx = cache_size >> shift; 427 } 428 429 pa = &pool_allocator_kmem; 430 #if defined(KMEM_POISON) 431 pc = pool_cache_init(cache_size, align, 0, flags, 432 name, pa, ipl, kmem_poison_ctor, 433 NULL, (void *)cache_size); 434 #else /* defined(KMEM_POISON) */ 435 pc = pool_cache_init(cache_size, align, 0, flags, 436 name, pa, ipl, NULL, NULL, NULL); 437 #endif /* defined(KMEM_POISON) */ 438 439 while (size <= cache_size) { 440 alloc_table[(size - 1) >> shift] = pc; 441 size += table_unit; 442 } 443 } 444 return maxidx; 445 } 446 447 void 448 kmem_init(void) 449 { 450 451 #ifdef KMEM_GUARD 452 uvm_kmguard_init(&kmem_guard, &kmem_guard_depth, &kmem_guard_size, 453 kmem_va_arena); 454 #endif 455 kmem_cache_maxidx = kmem_create_caches(kmem_cache_sizes, 456 kmem_cache, KMEM_MAXSIZE, KMEM_SHIFT, IPL_VM); 457 kmem_cache_big_maxidx = kmem_create_caches(kmem_cache_big_sizes, 458 kmem_cache_big, PAGE_SIZE, KMEM_BIG_SHIFT, IPL_VM); 459 } 460 461 size_t 462 kmem_roundup_size(size_t size) 463 { 464 465 return (size + (KMEM_ALIGN - 1)) & ~(KMEM_ALIGN - 1); 466 } 467 468 /* ---- debug */ 469 470 #if defined(KMEM_POISON) 471 472 #if defined(_LP64) 473 #define PRIME 0x9e37fffffffc0000UL 474 #else /* defined(_LP64) */ 475 #define PRIME 0x9e3779b1 476 #endif /* defined(_LP64) */ 477 478 static inline uint8_t 479 kmem_poison_pattern(const void *p) 480 { 481 482 return (uint8_t)(((uintptr_t)p) * PRIME 483 >> ((sizeof(uintptr_t) - sizeof(uint8_t))) * CHAR_BIT); 484 } 485 486 static int 487 kmem_poison_ctor(void *arg, void *obj, int flag) 488 { 489 size_t sz = (size_t)arg; 490 491 kmem_poison_fill(obj, sz); 492 493 return 0; 494 } 495 496 static void 497 kmem_poison_fill(void *p, size_t sz) 498 { 499 uint8_t *cp; 500 const uint8_t *ep; 501 502 cp = p; 503 ep = cp + sz; 504 while (cp < ep) { 505 *cp = kmem_poison_pattern(cp); 506 cp++; 507 } 508 } 509 510 static void 511 kmem_poison_check(void *p, size_t sz) 512 { 513 uint8_t *cp; 514 const uint8_t *ep; 515 516 cp = p; 517 ep = cp + sz; 518 while (cp < ep) { 519 const uint8_t expected = kmem_poison_pattern(cp); 520 521 if (*cp != expected) { 522 panic("%s: %p: 0x%02x != 0x%02x\n", 523 __func__, cp, *cp, expected); 524 } 525 cp++; 526 } 527 } 528 529 #endif /* defined(KMEM_POISON) */ 530 531 #if defined(KMEM_SIZE) 532 static void 533 kmem_size_set(void *p, size_t sz) 534 { 535 536 memcpy(p, &sz, sizeof(sz)); 537 } 538 539 static void 540 kmem_size_check(void *p, size_t sz) 541 { 542 size_t psz; 543 544 memcpy(&psz, p, sizeof(psz)); 545 if (psz != sz) { 546 panic("kmem_free(%p, %zu) != allocated size %zu", 547 (const uint8_t *)p + SIZE_SIZE, sz, psz); 548 } 549 } 550 #endif /* defined(KMEM_SIZE) */ 551 552 /* 553 * Used to dynamically allocate string with kmem accordingly to format. 554 */ 555 char * 556 kmem_asprintf(const char *fmt, ...) 557 { 558 int size __diagused, len; 559 va_list va; 560 char *str; 561 562 va_start(va, fmt); 563 len = vsnprintf(NULL, 0, fmt, va); 564 va_end(va); 565 566 str = kmem_alloc(len + 1, KM_SLEEP); 567 568 va_start(va, fmt); 569 size = vsnprintf(str, len + 1, fmt, va); 570 va_end(va); 571 572 KASSERT(size == len); 573 574 return str; 575 } 576
Indexes created Wed Sep 24 05:09:52 GMT 2025