1 /* $NetBSD: subr_kmem.c,v 1.76 2019/08/15 12:06:42 maxv Exp $ */ 2 3 /* 4 * Copyright (c) 2009-2015 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 and Maxime Villard. 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. This allocator has some debug features 60 * enabled with "option DIAGNOSTIC" and "option DEBUG". 61 */ 62 63 /* 64 * KMEM_SIZE: detect alloc/free size mismatch bugs. 65 * Prefix each allocations with a fixed-sized, aligned header and record 66 * the exact user-requested allocation size in it. When freeing, compare 67 * it with kmem_free's "size" argument. 68 * 69 * This option is enabled on DIAGNOSTIC. 70 * 71 * |CHUNK|CHUNK|CHUNK|CHUNK|CHUNK|CHUNK|CHUNK|CHUNK|CHUNK|CHUNK| 72 * +-----+-----+-----+-----+-----+-----+-----+-----+-----+---+-+ 73 * |/////| | | | | | | | | |U| 74 * |/HSZ/| | | | | | | | | |U| 75 * |/////| | | | | | | | | |U| 76 * +-----+-----+-----+-----+-----+-----+-----+-----+-----+---+-+ 77 * |Size | Buffer usable by the caller (requested size) |Unused\ 78 */ 79 80 #include <sys/cdefs.h> 81 __KERNEL_RCSID(0, "$NetBSD: subr_kmem.c,v 1.76 2019/08/15 12:06:42 maxv Exp $"); 82 83 #ifdef _KERNEL_OPT 84 #include "opt_kmem.h" 85 #endif 86 87 #include <sys/param.h> 88 #include <sys/callback.h> 89 #include <sys/kmem.h> 90 #include <sys/pool.h> 91 #include <sys/debug.h> 92 #include <sys/lockdebug.h> 93 #include <sys/cpu.h> 94 #include <sys/asan.h> 95 96 #include <uvm/uvm_extern.h> 97 #include <uvm/uvm_map.h> 98 99 #include <lib/libkern/libkern.h> 100 101 struct kmem_cache_info { 102 size_t kc_size; 103 const char * kc_name; 104 }; 105 106 static const struct kmem_cache_info kmem_cache_sizes[] = { 107 { 8, "kmem-8" }, 108 { 16, "kmem-16" }, 109 { 24, "kmem-24" }, 110 { 32, "kmem-32" }, 111 { 40, "kmem-40" }, 112 { 48, "kmem-48" }, 113 { 56, "kmem-56" }, 114 { 64, "kmem-64" }, 115 { 80, "kmem-80" }, 116 { 96, "kmem-96" }, 117 { 112, "kmem-112" }, 118 { 128, "kmem-128" }, 119 { 160, "kmem-160" }, 120 { 192, "kmem-192" }, 121 { 224, "kmem-224" }, 122 { 256, "kmem-256" }, 123 { 320, "kmem-320" }, 124 { 384, "kmem-384" }, 125 { 448, "kmem-448" }, 126 { 512, "kmem-512" }, 127 { 768, "kmem-768" }, 128 { 1024, "kmem-1024" }, 129 { 0, NULL } 130 }; 131 132 static const struct kmem_cache_info kmem_cache_big_sizes[] = { 133 { 2048, "kmem-2048" }, 134 { 4096, "kmem-4096" }, 135 { 8192, "kmem-8192" }, 136 { 16384, "kmem-16384" }, 137 { 0, NULL } 138 }; 139 140 /* 141 * KMEM_ALIGN is the smallest guaranteed alignment and also the 142 * smallest allocateable quantum. 143 * Every cache size >= CACHE_LINE_SIZE gets CACHE_LINE_SIZE alignment. 144 */ 145 #define KMEM_ALIGN 8 146 #define KMEM_SHIFT 3 147 #define KMEM_MAXSIZE 1024 148 #define KMEM_CACHE_COUNT (KMEM_MAXSIZE >> KMEM_SHIFT) 149 150 static pool_cache_t kmem_cache[KMEM_CACHE_COUNT] __cacheline_aligned; 151 static size_t kmem_cache_maxidx __read_mostly; 152 153 #define KMEM_BIG_ALIGN 2048 154 #define KMEM_BIG_SHIFT 11 155 #define KMEM_BIG_MAXSIZE 16384 156 #define KMEM_CACHE_BIG_COUNT (KMEM_BIG_MAXSIZE >> KMEM_BIG_SHIFT) 157 158 static pool_cache_t kmem_cache_big[KMEM_CACHE_BIG_COUNT] __cacheline_aligned; 159 static size_t kmem_cache_big_maxidx __read_mostly; 160 161 #if defined(DIAGNOSTIC) && defined(_HARDKERNEL) 162 #define KMEM_SIZE 163 #endif 164 165 #if defined(DEBUG) && defined(_HARDKERNEL) 166 static void *kmem_freecheck; 167 #endif 168 169 #if defined(KMEM_SIZE) 170 struct kmem_header { 171 size_t size; 172 } __aligned(KMEM_ALIGN); 173 #define SIZE_SIZE sizeof(struct kmem_header) 174 static void kmem_size_set(void *, size_t); 175 static void kmem_size_check(void *, size_t); 176 #else 177 #define SIZE_SIZE 0 178 #define kmem_size_set(p, sz) /* nothing */ 179 #define kmem_size_check(p, sz) /* nothing */ 180 #endif 181 182 CTASSERT(KM_SLEEP == PR_WAITOK); 183 CTASSERT(KM_NOSLEEP == PR_NOWAIT); 184 185 /* 186 * kmem_intr_alloc: allocate wired memory. 187 */ 188 void * 189 kmem_intr_alloc(size_t requested_size, km_flag_t kmflags) 190 { 191 #ifdef KASAN 192 const size_t origsize = requested_size; 193 #endif 194 size_t allocsz, index; 195 size_t size; 196 pool_cache_t pc; 197 uint8_t *p; 198 199 KASSERT(requested_size > 0); 200 201 KASSERT((kmflags & KM_SLEEP) || (kmflags & KM_NOSLEEP)); 202 KASSERT(!(kmflags & KM_SLEEP) || !(kmflags & KM_NOSLEEP)); 203 204 kasan_add_redzone(&requested_size); 205 size = kmem_roundup_size(requested_size); 206 allocsz = size + SIZE_SIZE; 207 208 if ((index = ((allocsz -1) >> KMEM_SHIFT)) 209 < kmem_cache_maxidx) { 210 pc = kmem_cache[index]; 211 } else if ((index = ((allocsz - 1) >> KMEM_BIG_SHIFT)) 212 < kmem_cache_big_maxidx) { 213 pc = kmem_cache_big[index]; 214 } else { 215 int ret = uvm_km_kmem_alloc(kmem_va_arena, 216 (vsize_t)round_page(size), 217 ((kmflags & KM_SLEEP) ? VM_SLEEP : VM_NOSLEEP) 218 | VM_INSTANTFIT, (vmem_addr_t *)&p); 219 if (ret) { 220 return NULL; 221 } 222 FREECHECK_OUT(&kmem_freecheck, p); 223 return p; 224 } 225 226 p = pool_cache_get(pc, kmflags); 227 228 if (__predict_true(p != NULL)) { 229 FREECHECK_OUT(&kmem_freecheck, p); 230 kmem_size_set(p, requested_size); 231 p += SIZE_SIZE; 232 kasan_mark(p, origsize, size, KASAN_KMEM_REDZONE); 233 return p; 234 } 235 return p; 236 } 237 238 /* 239 * kmem_intr_zalloc: allocate zeroed wired memory. 240 */ 241 void * 242 kmem_intr_zalloc(size_t size, km_flag_t kmflags) 243 { 244 void *p; 245 246 p = kmem_intr_alloc(size, kmflags); 247 if (p != NULL) { 248 memset(p, 0, size); 249 } 250 return p; 251 } 252 253 /* 254 * kmem_intr_free: free wired memory allocated by kmem_alloc. 255 */ 256 void 257 kmem_intr_free(void *p, size_t requested_size) 258 { 259 size_t allocsz, index; 260 size_t size; 261 pool_cache_t pc; 262 263 KASSERT(p != NULL); 264 KASSERT(requested_size > 0); 265 266 kasan_add_redzone(&requested_size); 267 size = kmem_roundup_size(requested_size); 268 allocsz = size + SIZE_SIZE; 269 270 if ((index = ((allocsz -1) >> KMEM_SHIFT)) 271 < kmem_cache_maxidx) { 272 pc = kmem_cache[index]; 273 } else if ((index = ((allocsz - 1) >> KMEM_BIG_SHIFT)) 274 < kmem_cache_big_maxidx) { 275 pc = kmem_cache_big[index]; 276 } else { 277 FREECHECK_IN(&kmem_freecheck, p); 278 uvm_km_kmem_free(kmem_va_arena, (vaddr_t)p, 279 round_page(size)); 280 return; 281 } 282 283 kasan_mark(p, size, size, 0); 284 285 p = (uint8_t *)p - SIZE_SIZE; 286 kmem_size_check(p, requested_size); 287 FREECHECK_IN(&kmem_freecheck, p); 288 LOCKDEBUG_MEM_CHECK(p, size); 289 290 pool_cache_put(pc, p); 291 } 292 293 /* -------------------------------- Kmem API -------------------------------- */ 294 295 /* 296 * kmem_alloc: allocate wired memory. 297 * => must not be called from interrupt context. 298 */ 299 void * 300 kmem_alloc(size_t size, km_flag_t kmflags) 301 { 302 void *v; 303 304 KASSERTMSG((!cpu_intr_p() && !cpu_softintr_p()), 305 "kmem(9) should not be used from the interrupt context"); 306 v = kmem_intr_alloc(size, kmflags); 307 KASSERT(v || (kmflags & KM_NOSLEEP) != 0); 308 return v; 309 } 310 311 /* 312 * kmem_zalloc: allocate zeroed wired memory. 313 * => must not be called from interrupt context. 314 */ 315 void * 316 kmem_zalloc(size_t size, km_flag_t kmflags) 317 { 318 void *v; 319 320 KASSERTMSG((!cpu_intr_p() && !cpu_softintr_p()), 321 "kmem(9) should not be used from the interrupt context"); 322 v = kmem_intr_zalloc(size, kmflags); 323 KASSERT(v || (kmflags & KM_NOSLEEP) != 0); 324 return v; 325 } 326 327 /* 328 * kmem_free: free wired memory allocated by kmem_alloc. 329 * => must not be called from interrupt context. 330 */ 331 void 332 kmem_free(void *p, size_t size) 333 { 334 KASSERT(!cpu_intr_p()); 335 KASSERT(!cpu_softintr_p()); 336 kmem_intr_free(p, size); 337 } 338 339 static size_t 340 kmem_create_caches(const struct kmem_cache_info *array, 341 pool_cache_t alloc_table[], size_t maxsize, int shift, int ipl) 342 { 343 size_t maxidx = 0; 344 size_t table_unit = (1 << shift); 345 size_t size = table_unit; 346 int i; 347 348 for (i = 0; array[i].kc_size != 0 ; i++) { 349 const char *name = array[i].kc_name; 350 size_t cache_size = array[i].kc_size; 351 struct pool_allocator *pa; 352 int flags = 0; 353 pool_cache_t pc; 354 size_t align; 355 356 if ((cache_size & (CACHE_LINE_SIZE - 1)) == 0) 357 align = CACHE_LINE_SIZE; 358 else if ((cache_size & (PAGE_SIZE - 1)) == 0) 359 align = PAGE_SIZE; 360 else 361 align = KMEM_ALIGN; 362 363 if (cache_size < CACHE_LINE_SIZE) 364 flags |= PR_NOTOUCH; 365 366 /* check if we reached the requested size */ 367 if (cache_size > maxsize || cache_size > PAGE_SIZE) { 368 break; 369 } 370 if ((cache_size >> shift) > maxidx) { 371 maxidx = cache_size >> shift; 372 } 373 374 if ((cache_size >> shift) > maxidx) { 375 maxidx = cache_size >> shift; 376 } 377 378 pa = &pool_allocator_kmem; 379 pc = pool_cache_init(cache_size, align, 0, flags, 380 name, pa, ipl, NULL, NULL, NULL); 381 382 while (size <= cache_size) { 383 alloc_table[(size - 1) >> shift] = pc; 384 size += table_unit; 385 } 386 } 387 return maxidx; 388 } 389 390 void 391 kmem_init(void) 392 { 393 kmem_cache_maxidx = kmem_create_caches(kmem_cache_sizes, 394 kmem_cache, KMEM_MAXSIZE, KMEM_SHIFT, IPL_VM); 395 kmem_cache_big_maxidx = kmem_create_caches(kmem_cache_big_sizes, 396 kmem_cache_big, PAGE_SIZE, KMEM_BIG_SHIFT, IPL_VM); 397 } 398 399 size_t 400 kmem_roundup_size(size_t size) 401 { 402 return (size + (KMEM_ALIGN - 1)) & ~(KMEM_ALIGN - 1); 403 } 404 405 /* 406 * Used to dynamically allocate string with kmem accordingly to format. 407 */ 408 char * 409 kmem_asprintf(const char *fmt, ...) 410 { 411 int size __diagused, len; 412 va_list va; 413 char *str; 414 415 va_start(va, fmt); 416 len = vsnprintf(NULL, 0, fmt, va); 417 va_end(va); 418 419 str = kmem_alloc(len + 1, KM_SLEEP); 420 421 va_start(va, fmt); 422 size = vsnprintf(str, len + 1, fmt, va); 423 va_end(va); 424 425 KASSERT(size == len); 426 427 return str; 428 } 429 430 char * 431 kmem_strdupsize(const char *str, size_t *lenp, km_flag_t flags) 432 { 433 size_t len = strlen(str) + 1; 434 char *ptr = kmem_alloc(len, flags); 435 if (ptr == NULL) 436 return NULL; 437 438 if (lenp) 439 *lenp = len; 440 memcpy(ptr, str, len); 441 return ptr; 442 } 443 444 char * 445 kmem_strndup(const char *str, size_t maxlen, km_flag_t flags) 446 { 447 KASSERT(str != NULL); 448 KASSERT(maxlen != 0); 449 450 size_t len = strnlen(str, maxlen); 451 char *ptr = kmem_alloc(len + 1, flags); 452 if (ptr == NULL) 453 return NULL; 454 455 memcpy(ptr, str, len); 456 ptr[len] = '\0'; 457 458 return ptr; 459 } 460 461 void 462 kmem_strfree(char *str) 463 { 464 if (str == NULL) 465 return; 466 467 kmem_free(str, strlen(str) + 1); 468 } 469 470 /* --------------------------- DEBUG / DIAGNOSTIC --------------------------- */ 471 472 #if defined(KMEM_SIZE) 473 static void 474 kmem_size_set(void *p, size_t sz) 475 { 476 struct kmem_header *hd; 477 hd = (struct kmem_header *)p; 478 hd->size = sz; 479 } 480 481 static void 482 kmem_size_check(void *p, size_t sz) 483 { 484 struct kmem_header *hd; 485 size_t hsz; 486 487 hd = (struct kmem_header *)p; 488 hsz = hd->size; 489 490 if (hsz != sz) { 491 panic("kmem_free(%p, %zu) != allocated size %zu", 492 (const uint8_t *)p + SIZE_SIZE, sz, hsz); 493 } 494 495 hd->size = -1; 496 } 497 #endif /* defined(KMEM_SIZE) */ 498