subr_kmem.c revision 1.50.4.1
1 /* $NetBSD: subr_kmem.c,v 1.50.4.1 2014/05/18 17:46:07 rmind 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". 64 * 65 * KMEM_POISON 66 * Try to detect modify-after-free bugs. 67 * 68 * Fill freed (in the sense of kmem_free) memory with a garbage pattern. 69 * Check the pattern on allocation. 70 * 71 * KMEM_REDZONE 72 * Try to detect overrun bugs. 73 * 74 * Allocate some more bytes for each allocation. 75 * The extra bytes are checked by KMEM_POISON on kmem_free. 76 * 77 * KMEM_SIZE 78 * Try to detect alloc/free size mismatch bugs. 79 * 80 * Prefix each allocations with a fixed-sized header and record 81 * the exact user-requested allocation size in it. 82 * When freeing, compare it with kmem_free's "size" argument. 83 * 84 * KMEM_GUARD 85 * See the below "kmguard" section. 86 */ 87 88 /* 89 * kmguard 90 * 91 * A kernel with "option DEBUG" has "kmguard" debugging feature compiled in. 92 * See the comment in uvm/uvm_kmguard.c for what kind of bugs it tries to 93 * detect. Even if compiled in, it's disabled by default because it's very 94 * expensive. You can enable it on boot by: 95 * 96 * boot -d 97 * db> w kmem_guard_depth 0t30000 98 * db> c 99 * 100 * The default value of kmem_guard_depth is 0, which means disabled. 101 * It can be changed by KMEM_GUARD_DEPTH kernel config option. 102 */ 103 104 #include <sys/cdefs.h> 105 __KERNEL_RCSID(0, "$NetBSD: subr_kmem.c,v 1.50.4.1 2014/05/18 17:46:07 rmind Exp $"); 106 107 #include <sys/param.h> 108 #include <sys/callback.h> 109 #include <sys/kmem.h> 110 #include <sys/pool.h> 111 #include <sys/debug.h> 112 #include <sys/lockdebug.h> 113 #include <sys/cpu.h> 114 115 #include <uvm/uvm_extern.h> 116 #include <uvm/uvm_map.h> 117 #include <uvm/uvm_kmguard.h> 118 119 #include <lib/libkern/libkern.h> 120 121 struct kmem_cache_info { 122 size_t kc_size; 123 const char * kc_name; 124 }; 125 126 static const struct kmem_cache_info kmem_cache_sizes[] = { 127 { 8, "kmem-8" }, 128 { 16, "kmem-16" }, 129 { 24, "kmem-24" }, 130 { 32, "kmem-32" }, 131 { 40, "kmem-40" }, 132 { 48, "kmem-48" }, 133 { 56, "kmem-56" }, 134 { 64, "kmem-64" }, 135 { 80, "kmem-80" }, 136 { 96, "kmem-96" }, 137 { 112, "kmem-112" }, 138 { 128, "kmem-128" }, 139 { 160, "kmem-160" }, 140 { 192, "kmem-192" }, 141 { 224, "kmem-224" }, 142 { 256, "kmem-256" }, 143 { 320, "kmem-320" }, 144 { 384, "kmem-384" }, 145 { 448, "kmem-448" }, 146 { 512, "kmem-512" }, 147 { 768, "kmem-768" }, 148 { 1024, "kmem-1024" }, 149 { 0, NULL } 150 }; 151 152 static const struct kmem_cache_info kmem_cache_big_sizes[] = { 153 { 2048, "kmem-2048" }, 154 { 4096, "kmem-4096" }, 155 { 8192, "kmem-8192" }, 156 { 16384, "kmem-16384" }, 157 { 0, NULL } 158 }; 159 160 /* 161 * KMEM_ALIGN is the smallest guaranteed alignment and also the 162 * smallest allocateable quantum. 163 * Every cache size >= CACHE_LINE_SIZE gets CACHE_LINE_SIZE alignment. 164 */ 165 #define KMEM_ALIGN 8 166 #define KMEM_SHIFT 3 167 #define KMEM_MAXSIZE 1024 168 #define KMEM_CACHE_COUNT (KMEM_MAXSIZE >> KMEM_SHIFT) 169 170 static pool_cache_t kmem_cache[KMEM_CACHE_COUNT] __cacheline_aligned; 171 static size_t kmem_cache_maxidx __read_mostly; 172 173 #define KMEM_BIG_ALIGN 2048 174 #define KMEM_BIG_SHIFT 11 175 #define KMEM_BIG_MAXSIZE 16384 176 #define KMEM_CACHE_BIG_COUNT (KMEM_BIG_MAXSIZE >> KMEM_BIG_SHIFT) 177 178 static pool_cache_t kmem_cache_big[KMEM_CACHE_BIG_COUNT] __cacheline_aligned; 179 static size_t kmem_cache_big_maxidx __read_mostly; 180 181 182 #if defined(DEBUG) && defined(_HARDKERNEL) 183 #ifndef KMEM_GUARD_DEPTH 184 #define KMEM_GUARD_DEPTH 0 185 #endif 186 int kmem_guard_depth = KMEM_GUARD_DEPTH; 187 size_t kmem_guard_size; 188 static struct uvm_kmguard kmem_guard; 189 static void *kmem_freecheck; 190 #define KMEM_POISON 191 #define KMEM_REDZONE 192 #define KMEM_SIZE 193 #define KMEM_GUARD 194 #endif /* defined(DEBUG) */ 195 196 #if defined(KMEM_POISON) 197 static int kmem_poison_ctor(void *, void *, int); 198 static void kmem_poison_fill(void *, size_t); 199 static void kmem_poison_check(void *, size_t); 200 #else /* defined(KMEM_POISON) */ 201 #define kmem_poison_fill(p, sz) /* nothing */ 202 #define kmem_poison_check(p, sz) /* nothing */ 203 #endif /* defined(KMEM_POISON) */ 204 205 #if defined(KMEM_REDZONE) 206 #define REDZONE_SIZE 1 207 #else /* defined(KMEM_REDZONE) */ 208 #define REDZONE_SIZE 0 209 #endif /* defined(KMEM_REDZONE) */ 210 211 #if defined(KMEM_SIZE) 212 #define SIZE_SIZE (MAX(KMEM_ALIGN, sizeof(size_t))) 213 static void kmem_size_set(void *, size_t); 214 static void kmem_size_check(void *, size_t); 215 #else 216 #define SIZE_SIZE 0 217 #define kmem_size_set(p, sz) /* nothing */ 218 #define kmem_size_check(p, sz) /* nothing */ 219 #endif 220 221 CTASSERT(KM_SLEEP == PR_WAITOK); 222 CTASSERT(KM_NOSLEEP == PR_NOWAIT); 223 224 /* 225 * kmem_intr_alloc: allocate wired memory. 226 */ 227 228 void * 229 kmem_intr_alloc(size_t requested_size, km_flag_t kmflags) 230 { 231 size_t allocsz, index; 232 size_t size; 233 pool_cache_t pc; 234 uint8_t *p; 235 236 KASSERT(requested_size > 0); 237 238 #ifdef KMEM_GUARD 239 if (requested_size <= kmem_guard_size) { 240 return uvm_kmguard_alloc(&kmem_guard, requested_size, 241 (kmflags & KM_SLEEP) != 0); 242 } 243 #endif 244 size = kmem_roundup_size(requested_size); 245 allocsz = size + REDZONE_SIZE + SIZE_SIZE; 246 247 if ((index = ((allocsz -1) >> KMEM_SHIFT)) 248 < kmem_cache_maxidx) { 249 pc = kmem_cache[index]; 250 } else if ((index = ((allocsz - 1) >> KMEM_BIG_SHIFT)) 251 < kmem_cache_big_maxidx) { 252 pc = kmem_cache_big[index]; 253 } else { 254 int ret = uvm_km_kmem_alloc(kmem_va_arena, 255 (vsize_t)round_page(size), 256 ((kmflags & KM_SLEEP) ? VM_SLEEP : VM_NOSLEEP) 257 | VM_INSTANTFIT, (vmem_addr_t *)&p); 258 if (ret) { 259 return NULL; 260 } 261 FREECHECK_OUT(&kmem_freecheck, p); 262 return p; 263 } 264 265 p = pool_cache_get(pc, kmflags); 266 267 if (__predict_true(p != NULL)) { 268 kmem_poison_check(p, size); 269 FREECHECK_OUT(&kmem_freecheck, p); 270 kmem_size_set(p, requested_size); 271 272 return p + SIZE_SIZE; 273 } 274 return p; 275 } 276 277 /* 278 * kmem_intr_zalloc: allocate zeroed wired memory. 279 */ 280 281 void * 282 kmem_intr_zalloc(size_t size, km_flag_t kmflags) 283 { 284 void *p; 285 286 p = kmem_intr_alloc(size, kmflags); 287 if (p != NULL) { 288 memset(p, 0, size); 289 } 290 return p; 291 } 292 293 /* 294 * kmem_intr_free: free wired memory allocated by kmem_alloc. 295 */ 296 297 void 298 kmem_intr_free(void *p, size_t requested_size) 299 { 300 size_t allocsz, index; 301 size_t size; 302 pool_cache_t pc; 303 304 KASSERT(p != NULL); 305 KASSERT(requested_size > 0); 306 307 #ifdef KMEM_GUARD 308 if (requested_size <= kmem_guard_size) { 309 uvm_kmguard_free(&kmem_guard, requested_size, p); 310 return; 311 } 312 #endif 313 size = kmem_roundup_size(requested_size); 314 allocsz = size + REDZONE_SIZE + SIZE_SIZE; 315 316 if ((index = ((allocsz -1) >> KMEM_SHIFT)) 317 < kmem_cache_maxidx) { 318 pc = kmem_cache[index]; 319 } else if ((index = ((allocsz - 1) >> KMEM_BIG_SHIFT)) 320 < kmem_cache_big_maxidx) { 321 pc = kmem_cache_big[index]; 322 } else { 323 FREECHECK_IN(&kmem_freecheck, p); 324 uvm_km_kmem_free(kmem_va_arena, (vaddr_t)p, 325 round_page(size)); 326 return; 327 } 328 329 p = (uint8_t *)p - SIZE_SIZE; 330 kmem_size_check(p, requested_size); 331 FREECHECK_IN(&kmem_freecheck, p); 332 LOCKDEBUG_MEM_CHECK(p, size); 333 kmem_poison_check((uint8_t *)p + SIZE_SIZE + size, 334 allocsz - (SIZE_SIZE + size)); 335 kmem_poison_fill(p, allocsz); 336 337 pool_cache_put(pc, p); 338 } 339 340 /* ---- kmem API */ 341 342 /* 343 * kmem_alloc: allocate wired memory. 344 * => must not be called from interrupt context. 345 */ 346 347 void * 348 kmem_alloc(size_t size, km_flag_t kmflags) 349 { 350 351 KASSERTMSG((!cpu_intr_p() && !cpu_softintr_p()), 352 "kmem(9) should not be used from the interrupt context"); 353 return kmem_intr_alloc(size, kmflags); 354 } 355 356 /* 357 * kmem_zalloc: allocate zeroed wired memory. 358 * => must not be called from interrupt context. 359 */ 360 361 void * 362 kmem_zalloc(size_t size, km_flag_t kmflags) 363 { 364 365 KASSERTMSG((!cpu_intr_p() && !cpu_softintr_p()), 366 "kmem(9) should not be used from the interrupt context"); 367 return kmem_intr_zalloc(size, kmflags); 368 } 369 370 /* 371 * kmem_free: free wired memory allocated by kmem_alloc. 372 * => must not be called from interrupt context. 373 */ 374 375 void 376 kmem_free(void *p, size_t size) 377 { 378 379 KASSERT(!cpu_intr_p()); 380 KASSERT(!cpu_softintr_p()); 381 kmem_intr_free(p, size); 382 } 383 384 static size_t 385 kmem_create_caches(const struct kmem_cache_info *array, 386 pool_cache_t alloc_table[], size_t maxsize, int shift, int ipl) 387 { 388 size_t maxidx = 0; 389 size_t table_unit = (1 << shift); 390 size_t size = table_unit; 391 int i; 392 393 for (i = 0; array[i].kc_size != 0 ; i++) { 394 const char *name = array[i].kc_name; 395 size_t cache_size = array[i].kc_size; 396 struct pool_allocator *pa; 397 int flags = PR_NOALIGN; 398 pool_cache_t pc; 399 size_t align; 400 401 if ((cache_size & (CACHE_LINE_SIZE - 1)) == 0) 402 align = CACHE_LINE_SIZE; 403 else if ((cache_size & (PAGE_SIZE - 1)) == 0) 404 align = PAGE_SIZE; 405 else 406 align = KMEM_ALIGN; 407 408 if (cache_size < CACHE_LINE_SIZE) 409 flags |= PR_NOTOUCH; 410 411 /* check if we reached the requested size */ 412 if (cache_size > maxsize || cache_size > PAGE_SIZE) { 413 break; 414 } 415 if ((cache_size >> shift) > maxidx) { 416 maxidx = cache_size >> shift; 417 } 418 419 if ((cache_size >> shift) > maxidx) { 420 maxidx = cache_size >> shift; 421 } 422 423 pa = &pool_allocator_kmem; 424 #if defined(KMEM_POISON) 425 pc = pool_cache_init(cache_size, align, 0, flags, 426 name, pa, ipl, kmem_poison_ctor, 427 NULL, (void *)cache_size); 428 #else /* defined(KMEM_POISON) */ 429 pc = pool_cache_init(cache_size, align, 0, flags, 430 name, pa, ipl, NULL, NULL, NULL); 431 #endif /* defined(KMEM_POISON) */ 432 433 while (size <= cache_size) { 434 alloc_table[(size - 1) >> shift] = pc; 435 size += table_unit; 436 } 437 } 438 return maxidx; 439 } 440 441 void 442 kmem_init(void) 443 { 444 445 #ifdef KMEM_GUARD 446 uvm_kmguard_init(&kmem_guard, &kmem_guard_depth, &kmem_guard_size, 447 kmem_va_arena); 448 #endif 449 kmem_cache_maxidx = kmem_create_caches(kmem_cache_sizes, 450 kmem_cache, KMEM_MAXSIZE, KMEM_SHIFT, IPL_VM); 451 kmem_cache_big_maxidx = kmem_create_caches(kmem_cache_big_sizes, 452 kmem_cache_big, PAGE_SIZE, KMEM_BIG_SHIFT, IPL_VM); 453 } 454 455 size_t 456 kmem_roundup_size(size_t size) 457 { 458 459 return (size + (KMEM_ALIGN - 1)) & ~(KMEM_ALIGN - 1); 460 } 461 462 /* ---- debug */ 463 464 #if defined(KMEM_POISON) 465 466 #if defined(_LP64) 467 #define PRIME 0x9e37fffffffc0000UL 468 #else /* defined(_LP64) */ 469 #define PRIME 0x9e3779b1 470 #endif /* defined(_LP64) */ 471 472 static inline uint8_t 473 kmem_poison_pattern(const void *p) 474 { 475 476 return (uint8_t)(((uintptr_t)p) * PRIME 477 >> ((sizeof(uintptr_t) - sizeof(uint8_t))) * CHAR_BIT); 478 } 479 480 static int 481 kmem_poison_ctor(void *arg, void *obj, int flag) 482 { 483 size_t sz = (size_t)arg; 484 485 kmem_poison_fill(obj, sz); 486 487 return 0; 488 } 489 490 static void 491 kmem_poison_fill(void *p, size_t sz) 492 { 493 uint8_t *cp; 494 const uint8_t *ep; 495 496 cp = p; 497 ep = cp + sz; 498 while (cp < ep) { 499 *cp = kmem_poison_pattern(cp); 500 cp++; 501 } 502 } 503 504 static void 505 kmem_poison_check(void *p, size_t sz) 506 { 507 uint8_t *cp; 508 const uint8_t *ep; 509 510 cp = p; 511 ep = cp + sz; 512 while (cp < ep) { 513 const uint8_t expected = kmem_poison_pattern(cp); 514 515 if (*cp != expected) { 516 panic("%s: %p: 0x%02x != 0x%02x\n", 517 __func__, cp, *cp, expected); 518 } 519 cp++; 520 } 521 } 522 523 #endif /* defined(KMEM_POISON) */ 524 525 #if defined(KMEM_SIZE) 526 static void 527 kmem_size_set(void *p, size_t sz) 528 { 529 530 memcpy(p, &sz, sizeof(sz)); 531 } 532 533 static void 534 kmem_size_check(void *p, size_t sz) 535 { 536 size_t psz; 537 538 memcpy(&psz, p, sizeof(psz)); 539 if (psz != sz) { 540 panic("kmem_free(%p, %zu) != allocated size %zu", 541 (const uint8_t *)p + SIZE_SIZE, sz, psz); 542 } 543 } 544 #endif /* defined(KMEM_SIZE) */ 545 546 /* 547 * Used to dynamically allocate string with kmem accordingly to format. 548 */ 549 char * 550 kmem_asprintf(const char *fmt, ...) 551 { 552 int size __diagused, len; 553 va_list va; 554 char *str; 555 556 va_start(va, fmt); 557 len = vsnprintf(NULL, 0, fmt, va); 558 va_end(va); 559 560 str = kmem_alloc(len + 1, KM_SLEEP); 561 562 va_start(va, fmt); 563 size = vsnprintf(str, len + 1, fmt, va); 564 va_end(va); 565 566 KASSERT(size == len); 567 568 return str; 569 } 570
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