1 /* $NetBSD: kern_malloc.c,v 1.119 2008/03/17 17:05:54 ad Exp $ */ 2 3 /* 4 * Copyright (c) 1987, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following 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 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)kern_malloc.c 8.4 (Berkeley) 5/20/95 32 */ 33 34 /* 35 * Copyright (c) 1996 Christopher G. Demetriou. All rights reserved. 36 * 37 * Redistribution and use in source and binary forms, with or without 38 * modification, are permitted provided that the following conditions 39 * are met: 40 * 1. Redistributions of source code must retain the above copyright 41 * notice, this list of conditions and the following disclaimer. 42 * 2. Redistributions in binary form must reproduce the above copyright 43 * notice, this list of conditions and the following disclaimer in the 44 * documentation and/or other materials provided with the distribution. 45 * 3. All advertising materials mentioning features or use of this software 46 * must display the following acknowledgement: 47 * This product includes software developed by the University of 48 * California, Berkeley and its contributors. 49 * 4. Neither the name of the University nor the names of its contributors 50 * may be used to endorse or promote products derived from this software 51 * without specific prior written permission. 52 * 53 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 54 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 55 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 56 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 57 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 58 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 59 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 60 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 61 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 62 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 63 * SUCH DAMAGE. 64 * 65 * @(#)kern_malloc.c 8.4 (Berkeley) 5/20/95 66 */ 67 68 #include <sys/cdefs.h> 69 __KERNEL_RCSID(0, "$NetBSD: kern_malloc.c,v 1.119 2008/03/17 17:05:54 ad Exp $"); 70 71 #include <sys/param.h> 72 #include <sys/proc.h> 73 #include <sys/kernel.h> 74 #include <sys/malloc.h> 75 #include <sys/systm.h> 76 #include <sys/debug.h> 77 #include <sys/mutex.h> 78 #include <sys/lockdebug.h> 79 80 #include <uvm/uvm_extern.h> 81 82 static struct vm_map_kernel kmem_map_store; 83 struct vm_map *kmem_map = NULL; 84 85 #include "opt_kmempages.h" 86 87 #ifdef NKMEMCLUSTERS 88 #error NKMEMCLUSTERS is obsolete; remove it from your kernel config file and use NKMEMPAGES instead or let the kernel auto-size 89 #endif 90 91 /* 92 * Default number of pages in kmem_map. We attempt to calculate this 93 * at run-time, but allow it to be either patched or set in the kernel 94 * config file. 95 */ 96 #ifndef NKMEMPAGES 97 #define NKMEMPAGES 0 98 #endif 99 int nkmempages = NKMEMPAGES; 100 101 /* 102 * Defaults for lower- and upper-bounds for the kmem_map page count. 103 * Can be overridden by kernel config options. 104 */ 105 #ifndef NKMEMPAGES_MIN 106 #define NKMEMPAGES_MIN NKMEMPAGES_MIN_DEFAULT 107 #endif 108 109 #ifndef NKMEMPAGES_MAX 110 #define NKMEMPAGES_MAX NKMEMPAGES_MAX_DEFAULT 111 #endif 112 113 #include "opt_kmemstats.h" 114 #include "opt_malloclog.h" 115 #include "opt_malloc_debug.h" 116 117 #define MINALLOCSIZE (1 << MINBUCKET) 118 #define BUCKETINDX(size) \ 119 ((size) <= (MINALLOCSIZE * 128) \ 120 ? (size) <= (MINALLOCSIZE * 8) \ 121 ? (size) <= (MINALLOCSIZE * 2) \ 122 ? (size) <= (MINALLOCSIZE * 1) \ 123 ? (MINBUCKET + 0) \ 124 : (MINBUCKET + 1) \ 125 : (size) <= (MINALLOCSIZE * 4) \ 126 ? (MINBUCKET + 2) \ 127 : (MINBUCKET + 3) \ 128 : (size) <= (MINALLOCSIZE* 32) \ 129 ? (size) <= (MINALLOCSIZE * 16) \ 130 ? (MINBUCKET + 4) \ 131 : (MINBUCKET + 5) \ 132 : (size) <= (MINALLOCSIZE * 64) \ 133 ? (MINBUCKET + 6) \ 134 : (MINBUCKET + 7) \ 135 : (size) <= (MINALLOCSIZE * 2048) \ 136 ? (size) <= (MINALLOCSIZE * 512) \ 137 ? (size) <= (MINALLOCSIZE * 256) \ 138 ? (MINBUCKET + 8) \ 139 : (MINBUCKET + 9) \ 140 : (size) <= (MINALLOCSIZE * 1024) \ 141 ? (MINBUCKET + 10) \ 142 : (MINBUCKET + 11) \ 143 : (size) <= (MINALLOCSIZE * 8192) \ 144 ? (size) <= (MINALLOCSIZE * 4096) \ 145 ? (MINBUCKET + 12) \ 146 : (MINBUCKET + 13) \ 147 : (size) <= (MINALLOCSIZE * 16384) \ 148 ? (MINBUCKET + 14) \ 149 : (MINBUCKET + 15)) 150 151 /* 152 * Array of descriptors that describe the contents of each page 153 */ 154 struct kmemusage { 155 short ku_indx; /* bucket index */ 156 union { 157 u_short freecnt;/* for small allocations, free pieces in page */ 158 u_short pagecnt;/* for large allocations, pages alloced */ 159 } ku_un; 160 }; 161 #define ku_freecnt ku_un.freecnt 162 #define ku_pagecnt ku_un.pagecnt 163 164 struct kmembuckets kmembuckets[MINBUCKET + 16]; 165 struct kmemusage *kmemusage; 166 char *kmembase, *kmemlimit; 167 168 #ifdef DEBUG 169 static void *malloc_freecheck; 170 #endif 171 172 /* 173 * Turn virtual addresses into kmem map indicies 174 */ 175 #define btokup(addr) (&kmemusage[((char *)(addr) - kmembase) >> PGSHIFT]) 176 177 struct malloc_type *kmemstatistics; 178 179 #ifdef MALLOCLOG 180 #ifndef MALLOCLOGSIZE 181 #define MALLOCLOGSIZE 100000 182 #endif 183 184 struct malloclog { 185 void *addr; 186 long size; 187 struct malloc_type *type; 188 int action; 189 const char *file; 190 long line; 191 } malloclog[MALLOCLOGSIZE]; 192 193 long malloclogptr; 194 195 static void 196 domlog(void *a, long size, struct malloc_type *type, int action, 197 const char *file, long line) 198 { 199 200 malloclog[malloclogptr].addr = a; 201 malloclog[malloclogptr].size = size; 202 malloclog[malloclogptr].type = type; 203 malloclog[malloclogptr].action = action; 204 malloclog[malloclogptr].file = file; 205 malloclog[malloclogptr].line = line; 206 malloclogptr++; 207 if (malloclogptr >= MALLOCLOGSIZE) 208 malloclogptr = 0; 209 } 210 211 static void 212 hitmlog(void *a) 213 { 214 struct malloclog *lp; 215 long l; 216 217 #define PRT do { \ 218 lp = &malloclog[l]; \ 219 if (lp->addr == a && lp->action) { \ 220 printf("malloc log entry %ld:\n", l); \ 221 printf("\taddr = %p\n", lp->addr); \ 222 printf("\tsize = %ld\n", lp->size); \ 223 printf("\ttype = %s\n", lp->type->ks_shortdesc); \ 224 printf("\taction = %s\n", lp->action == 1 ? "alloc" : "free"); \ 225 printf("\tfile = %s\n", lp->file); \ 226 printf("\tline = %ld\n", lp->line); \ 227 } \ 228 } while (/* CONSTCOND */0) 229 230 for (l = malloclogptr; l < MALLOCLOGSIZE; l++) 231 PRT; 232 233 for (l = 0; l < malloclogptr; l++) 234 PRT; 235 #undef PRT 236 } 237 #endif /* MALLOCLOG */ 238 239 #ifdef DIAGNOSTIC 240 /* 241 * This structure provides a set of masks to catch unaligned frees. 242 */ 243 const long addrmask[] = { 0, 244 0x00000001, 0x00000003, 0x00000007, 0x0000000f, 245 0x0000001f, 0x0000003f, 0x0000007f, 0x000000ff, 246 0x000001ff, 0x000003ff, 0x000007ff, 0x00000fff, 247 0x00001fff, 0x00003fff, 0x00007fff, 0x0000ffff, 248 }; 249 250 /* 251 * The WEIRD_ADDR is used as known text to copy into free objects so 252 * that modifications after frees can be detected. 253 */ 254 #define WEIRD_ADDR ((uint32_t) 0xdeadbeef) 255 #ifdef DEBUG 256 #define MAX_COPY PAGE_SIZE 257 #else 258 #define MAX_COPY 32 259 #endif 260 261 /* 262 * Normally the freelist structure is used only to hold the list pointer 263 * for free objects. However, when running with diagnostics, the first 264 * 8/16 bytes of the structure is unused except for diagnostic information, 265 * and the free list pointer is at offset 8/16 in the structure. Since the 266 * first 8 bytes is the portion of the structure most often modified, this 267 * helps to detect memory reuse problems and avoid free list corruption. 268 */ 269 struct freelist { 270 uint32_t spare0; 271 #ifdef _LP64 272 uint32_t spare1; /* explicit padding */ 273 #endif 274 struct malloc_type *type; 275 void * next; 276 }; 277 #else /* !DIAGNOSTIC */ 278 struct freelist { 279 void * next; 280 }; 281 #endif /* DIAGNOSTIC */ 282 283 /* 284 * The following are standard, built-in malloc types and are not 285 * specific to any subsystem. 286 */ 287 MALLOC_DEFINE(M_DEVBUF, "devbuf", "device driver memory"); 288 MALLOC_DEFINE(M_DMAMAP, "DMA map", "bus_dma(9) structures"); 289 MALLOC_DEFINE(M_FREE, "free", "should be on free list"); 290 MALLOC_DEFINE(M_PCB, "pcb", "protocol control block"); 291 MALLOC_DEFINE(M_SOFTINTR, "softintr", "Softinterrupt structures"); 292 MALLOC_DEFINE(M_TEMP, "temp", "misc. temporary data buffers"); 293 294 /* XXX These should all be elsewhere. */ 295 MALLOC_DEFINE(M_RTABLE, "routetbl", "routing tables"); 296 MALLOC_DEFINE(M_FTABLE, "fragtbl", "fragment reassembly header"); 297 MALLOC_DEFINE(M_UFSMNT, "UFS mount", "UFS mount structure"); 298 MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure"); 299 MALLOC_DEFINE(M_IPMOPTS, "ip_moptions", "internet multicast options"); 300 MALLOC_DEFINE(M_IPMADDR, "in_multi", "internet multicast address"); 301 MALLOC_DEFINE(M_MRTABLE, "mrt", "multicast routing tables"); 302 MALLOC_DEFINE(M_BWMETER, "bwmeter", "multicast upcall bw meters"); 303 MALLOC_DEFINE(M_1394DATA, "1394data", "IEEE 1394 data buffers"); 304 305 kmutex_t malloc_lock; 306 307 /* 308 * Allocate a block of memory 309 */ 310 #ifdef MALLOCLOG 311 void * 312 _malloc(unsigned long size, struct malloc_type *ksp, int flags, 313 const char *file, long line) 314 #else 315 void * 316 malloc(unsigned long size, struct malloc_type *ksp, int flags) 317 #endif /* MALLOCLOG */ 318 { 319 struct kmembuckets *kbp; 320 struct kmemusage *kup; 321 struct freelist *freep; 322 long indx, npg, allocsize; 323 char *va, *cp, *savedlist; 324 #ifdef DIAGNOSTIC 325 uint32_t *end, *lp; 326 int copysize; 327 #endif 328 329 #ifdef LOCKDEBUG 330 if ((flags & M_NOWAIT) == 0) { 331 ASSERT_SLEEPABLE(); 332 } 333 #endif 334 #ifdef MALLOC_DEBUG 335 if (debug_malloc(size, ksp, flags, (void *) &va)) { 336 if (va != 0) 337 FREECHECK_OUT(&malloc_freecheck, (void *)va); 338 return ((void *) va); 339 } 340 #endif 341 indx = BUCKETINDX(size); 342 kbp = &kmembuckets[indx]; 343 mutex_spin_enter(&malloc_lock); 344 #ifdef KMEMSTATS 345 while (ksp->ks_memuse >= ksp->ks_limit) { 346 if (flags & M_NOWAIT) { 347 mutex_spin_exit(&malloc_lock); 348 return ((void *) NULL); 349 } 350 if (ksp->ks_limblocks < 65535) 351 ksp->ks_limblocks++; 352 mtsleep((void *)ksp, PSWP+2, ksp->ks_shortdesc, 0, 353 &malloc_lock); 354 } 355 ksp->ks_size |= 1 << indx; 356 #endif 357 #ifdef DIAGNOSTIC 358 copysize = 1 << indx < MAX_COPY ? 1 << indx : MAX_COPY; 359 #endif 360 if (kbp->kb_next == NULL) { 361 int s; 362 kbp->kb_last = NULL; 363 if (size > MAXALLOCSAVE) 364 allocsize = round_page(size); 365 else 366 allocsize = 1 << indx; 367 npg = btoc(allocsize); 368 mutex_spin_exit(&malloc_lock); 369 s = splvm(); 370 va = (void *) uvm_km_alloc(kmem_map, 371 (vsize_t)ctob(npg), 0, 372 ((flags & M_NOWAIT) ? UVM_KMF_NOWAIT : 0) | 373 ((flags & M_CANFAIL) ? UVM_KMF_CANFAIL : 0) | 374 UVM_KMF_WIRED); 375 splx(s); 376 if (__predict_false(va == NULL)) { 377 /* 378 * Kmem_malloc() can return NULL, even if it can 379 * wait, if there is no map space available, because 380 * it can't fix that problem. Neither can we, 381 * right now. (We should release pages which 382 * are completely free and which are in kmembuckets 383 * with too many free elements.) 384 */ 385 if ((flags & (M_NOWAIT|M_CANFAIL)) == 0) 386 panic("malloc: out of space in kmem_map"); 387 return (NULL); 388 } 389 mutex_spin_enter(&malloc_lock); 390 #ifdef KMEMSTATS 391 kbp->kb_total += kbp->kb_elmpercl; 392 #endif 393 kup = btokup(va); 394 kup->ku_indx = indx; 395 if (allocsize > MAXALLOCSAVE) { 396 if (npg > 65535) 397 panic("malloc: allocation too large"); 398 kup->ku_pagecnt = npg; 399 #ifdef KMEMSTATS 400 ksp->ks_memuse += allocsize; 401 #endif 402 goto out; 403 } 404 #ifdef KMEMSTATS 405 kup->ku_freecnt = kbp->kb_elmpercl; 406 kbp->kb_totalfree += kbp->kb_elmpercl; 407 #endif 408 /* 409 * Just in case we blocked while allocating memory, 410 * and someone else also allocated memory for this 411 * kmembucket, don't assume the list is still empty. 412 */ 413 savedlist = kbp->kb_next; 414 kbp->kb_next = cp = va + (npg << PAGE_SHIFT) - allocsize; 415 for (;;) { 416 freep = (struct freelist *)cp; 417 #ifdef DIAGNOSTIC 418 /* 419 * Copy in known text to detect modification 420 * after freeing. 421 */ 422 end = (uint32_t *)&cp[copysize]; 423 for (lp = (uint32_t *)cp; lp < end; lp++) 424 *lp = WEIRD_ADDR; 425 freep->type = M_FREE; 426 #endif /* DIAGNOSTIC */ 427 if (cp <= va) 428 break; 429 cp -= allocsize; 430 freep->next = cp; 431 } 432 freep->next = savedlist; 433 if (savedlist == NULL) 434 kbp->kb_last = (void *)freep; 435 } 436 va = kbp->kb_next; 437 kbp->kb_next = ((struct freelist *)va)->next; 438 #ifdef DIAGNOSTIC 439 freep = (struct freelist *)va; 440 /* XXX potential to get garbage pointer here. */ 441 if (kbp->kb_next) { 442 int rv; 443 vaddr_t addr = (vaddr_t)kbp->kb_next; 444 445 vm_map_lock(kmem_map); 446 rv = uvm_map_checkprot(kmem_map, addr, 447 addr + sizeof(struct freelist), VM_PROT_WRITE); 448 vm_map_unlock(kmem_map); 449 450 if (__predict_false(rv == 0)) { 451 printf("Data modified on freelist: " 452 "word %ld of object %p size %ld previous type %s " 453 "(invalid addr %p)\n", 454 (long)((int32_t *)&kbp->kb_next - (int32_t *)kbp), 455 va, size, "foo", kbp->kb_next); 456 #ifdef MALLOCLOG 457 hitmlog(va); 458 #endif 459 kbp->kb_next = NULL; 460 } 461 } 462 463 /* Fill the fields that we've used with WEIRD_ADDR */ 464 #ifdef _LP64 465 freep->type = (struct malloc_type *) 466 (WEIRD_ADDR | (((u_long) WEIRD_ADDR) << 32)); 467 #else 468 freep->type = (struct malloc_type *) WEIRD_ADDR; 469 #endif 470 end = (uint32_t *)&freep->next + 471 (sizeof(freep->next) / sizeof(int32_t)); 472 for (lp = (uint32_t *)&freep->next; lp < end; lp++) 473 *lp = WEIRD_ADDR; 474 475 /* and check that the data hasn't been modified. */ 476 end = (uint32_t *)&va[copysize]; 477 for (lp = (uint32_t *)va; lp < end; lp++) { 478 if (__predict_true(*lp == WEIRD_ADDR)) 479 continue; 480 printf("Data modified on freelist: " 481 "word %ld of object %p size %ld previous type %s " 482 "(0x%x != 0x%x)\n", 483 (long)(lp - (uint32_t *)va), va, size, 484 "bar", *lp, WEIRD_ADDR); 485 #ifdef MALLOCLOG 486 hitmlog(va); 487 #endif 488 break; 489 } 490 491 freep->spare0 = 0; 492 #endif /* DIAGNOSTIC */ 493 #ifdef KMEMSTATS 494 kup = btokup(va); 495 if (kup->ku_indx != indx) 496 panic("malloc: wrong bucket"); 497 if (kup->ku_freecnt == 0) 498 panic("malloc: lost data"); 499 kup->ku_freecnt--; 500 kbp->kb_totalfree--; 501 ksp->ks_memuse += 1 << indx; 502 out: 503 kbp->kb_calls++; 504 ksp->ks_inuse++; 505 ksp->ks_calls++; 506 if (ksp->ks_memuse > ksp->ks_maxused) 507 ksp->ks_maxused = ksp->ks_memuse; 508 #else 509 out: 510 #endif 511 #ifdef MALLOCLOG 512 domlog(va, size, ksp, 1, file, line); 513 #endif 514 mutex_spin_exit(&malloc_lock); 515 if ((flags & M_ZERO) != 0) 516 memset(va, 0, size); 517 FREECHECK_OUT(&malloc_freecheck, (void *)va); 518 return ((void *) va); 519 } 520 521 /* 522 * Free a block of memory allocated by malloc. 523 */ 524 #ifdef MALLOCLOG 525 void 526 _free(void *addr, struct malloc_type *ksp, const char *file, long line) 527 #else 528 void 529 free(void *addr, struct malloc_type *ksp) 530 #endif /* MALLOCLOG */ 531 { 532 struct kmembuckets *kbp; 533 struct kmemusage *kup; 534 struct freelist *freep; 535 long size; 536 #ifdef DIAGNOSTIC 537 void *cp; 538 int32_t *end, *lp; 539 long alloc, copysize; 540 #endif 541 542 FREECHECK_IN(&malloc_freecheck, addr); 543 #ifdef MALLOC_DEBUG 544 if (debug_free(addr, ksp)) 545 return; 546 #endif 547 548 #ifdef DIAGNOSTIC 549 /* 550 * Ensure that we're free'ing something that we could 551 * have allocated in the first place. That is, check 552 * to see that the address is within kmem_map. 553 */ 554 if (__predict_false((vaddr_t)addr < vm_map_min(kmem_map) || 555 (vaddr_t)addr >= vm_map_max(kmem_map))) 556 panic("free: addr %p not within kmem_map", addr); 557 #endif 558 559 kup = btokup(addr); 560 size = 1 << kup->ku_indx; 561 kbp = &kmembuckets[kup->ku_indx]; 562 563 LOCKDEBUG_MEM_CHECK(addr, 564 size <= MAXALLOCSAVE ? size : ctob(kup->ku_pagecnt)); 565 566 mutex_spin_enter(&malloc_lock); 567 #ifdef MALLOCLOG 568 domlog(addr, 0, ksp, 2, file, line); 569 #endif 570 #ifdef DIAGNOSTIC 571 /* 572 * Check for returns of data that do not point to the 573 * beginning of the allocation. 574 */ 575 if (size > PAGE_SIZE) 576 alloc = addrmask[BUCKETINDX(PAGE_SIZE)]; 577 else 578 alloc = addrmask[kup->ku_indx]; 579 if (((u_long)addr & alloc) != 0) 580 panic("free: unaligned addr %p, size %ld, type %s, mask %ld", 581 addr, size, ksp->ks_shortdesc, alloc); 582 #endif /* DIAGNOSTIC */ 583 if (size > MAXALLOCSAVE) { 584 uvm_km_free(kmem_map, (vaddr_t)addr, ctob(kup->ku_pagecnt), 585 UVM_KMF_WIRED); 586 #ifdef KMEMSTATS 587 size = kup->ku_pagecnt << PGSHIFT; 588 ksp->ks_memuse -= size; 589 kup->ku_indx = 0; 590 kup->ku_pagecnt = 0; 591 if (ksp->ks_memuse + size >= ksp->ks_limit && 592 ksp->ks_memuse < ksp->ks_limit) 593 wakeup((void *)ksp); 594 #ifdef DIAGNOSTIC 595 if (ksp->ks_inuse == 0) 596 panic("free 1: inuse 0, probable double free"); 597 #endif 598 ksp->ks_inuse--; 599 kbp->kb_total -= 1; 600 #endif 601 mutex_spin_exit(&malloc_lock); 602 return; 603 } 604 freep = (struct freelist *)addr; 605 #ifdef DIAGNOSTIC 606 /* 607 * Check for multiple frees. Use a quick check to see if 608 * it looks free before laboriously searching the freelist. 609 */ 610 if (__predict_false(freep->spare0 == WEIRD_ADDR)) { 611 for (cp = kbp->kb_next; cp; 612 cp = ((struct freelist *)cp)->next) { 613 if (addr != cp) 614 continue; 615 printf("multiply freed item %p\n", addr); 616 #ifdef MALLOCLOG 617 hitmlog(addr); 618 #endif 619 panic("free: duplicated free"); 620 } 621 } 622 623 /* 624 * Copy in known text to detect modification after freeing 625 * and to make it look free. Also, save the type being freed 626 * so we can list likely culprit if modification is detected 627 * when the object is reallocated. 628 */ 629 copysize = size < MAX_COPY ? size : MAX_COPY; 630 end = (int32_t *)&((char *)addr)[copysize]; 631 for (lp = (int32_t *)addr; lp < end; lp++) 632 *lp = WEIRD_ADDR; 633 freep->type = ksp; 634 #endif /* DIAGNOSTIC */ 635 #ifdef KMEMSTATS 636 kup->ku_freecnt++; 637 if (kup->ku_freecnt >= kbp->kb_elmpercl) { 638 if (kup->ku_freecnt > kbp->kb_elmpercl) 639 panic("free: multiple frees"); 640 else if (kbp->kb_totalfree > kbp->kb_highwat) 641 kbp->kb_couldfree++; 642 } 643 kbp->kb_totalfree++; 644 ksp->ks_memuse -= size; 645 if (ksp->ks_memuse + size >= ksp->ks_limit && 646 ksp->ks_memuse < ksp->ks_limit) 647 wakeup((void *)ksp); 648 #ifdef DIAGNOSTIC 649 if (ksp->ks_inuse == 0) 650 panic("free 2: inuse 0, probable double free"); 651 #endif 652 ksp->ks_inuse--; 653 #endif 654 if (kbp->kb_next == NULL) 655 kbp->kb_next = addr; 656 else 657 ((struct freelist *)kbp->kb_last)->next = addr; 658 freep->next = NULL; 659 kbp->kb_last = addr; 660 mutex_spin_exit(&malloc_lock); 661 } 662 663 /* 664 * Change the size of a block of memory. 665 */ 666 void * 667 realloc(void *curaddr, unsigned long newsize, struct malloc_type *ksp, 668 int flags) 669 { 670 struct kmemusage *kup; 671 unsigned long cursize; 672 void *newaddr; 673 #ifdef DIAGNOSTIC 674 long alloc; 675 #endif 676 677 /* 678 * realloc() with a NULL pointer is the same as malloc(). 679 */ 680 if (curaddr == NULL) 681 return (malloc(newsize, ksp, flags)); 682 683 /* 684 * realloc() with zero size is the same as free(). 685 */ 686 if (newsize == 0) { 687 free(curaddr, ksp); 688 return (NULL); 689 } 690 691 #ifdef LOCKDEBUG 692 if ((flags & M_NOWAIT) == 0) { 693 ASSERT_SLEEPABLE(); 694 } 695 #endif 696 697 /* 698 * Find out how large the old allocation was (and do some 699 * sanity checking). 700 */ 701 kup = btokup(curaddr); 702 cursize = 1 << kup->ku_indx; 703 704 #ifdef DIAGNOSTIC 705 /* 706 * Check for returns of data that do not point to the 707 * beginning of the allocation. 708 */ 709 if (cursize > PAGE_SIZE) 710 alloc = addrmask[BUCKETINDX(PAGE_SIZE)]; 711 else 712 alloc = addrmask[kup->ku_indx]; 713 if (((u_long)curaddr & alloc) != 0) 714 panic("realloc: " 715 "unaligned addr %p, size %ld, type %s, mask %ld\n", 716 curaddr, cursize, ksp->ks_shortdesc, alloc); 717 #endif /* DIAGNOSTIC */ 718 719 if (cursize > MAXALLOCSAVE) 720 cursize = ctob(kup->ku_pagecnt); 721 722 /* 723 * If we already actually have as much as they want, we're done. 724 */ 725 if (newsize <= cursize) 726 return (curaddr); 727 728 /* 729 * Can't satisfy the allocation with the existing block. 730 * Allocate a new one and copy the data. 731 */ 732 newaddr = malloc(newsize, ksp, flags); 733 if (__predict_false(newaddr == NULL)) { 734 /* 735 * malloc() failed, because flags included M_NOWAIT. 736 * Return NULL to indicate that failure. The old 737 * pointer is still valid. 738 */ 739 return (NULL); 740 } 741 memcpy(newaddr, curaddr, cursize); 742 743 /* 744 * We were successful: free the old allocation and return 745 * the new one. 746 */ 747 free(curaddr, ksp); 748 return (newaddr); 749 } 750 751 /* 752 * Roundup size to the actual allocation size. 753 */ 754 unsigned long 755 malloc_roundup(unsigned long size) 756 { 757 758 if (size > MAXALLOCSAVE) 759 return (roundup(size, PAGE_SIZE)); 760 else 761 return (1 << BUCKETINDX(size)); 762 } 763 764 /* 765 * Add a malloc type to the system. 766 */ 767 void 768 malloc_type_attach(struct malloc_type *type) 769 { 770 771 if (nkmempages == 0) 772 panic("malloc_type_attach: nkmempages == 0"); 773 774 if (type->ks_magic != M_MAGIC) 775 panic("malloc_type_attach: bad magic"); 776 777 #ifdef DIAGNOSTIC 778 { 779 struct malloc_type *ksp; 780 for (ksp = kmemstatistics; ksp != NULL; ksp = ksp->ks_next) { 781 if (ksp == type) 782 panic("malloc_type_attach: already on list"); 783 } 784 } 785 #endif 786 787 #ifdef KMEMSTATS 788 if (type->ks_limit == 0) 789 type->ks_limit = ((u_long)nkmempages << PAGE_SHIFT) * 6U / 10U; 790 #else 791 type->ks_limit = 0; 792 #endif 793 794 type->ks_next = kmemstatistics; 795 kmemstatistics = type; 796 } 797 798 /* 799 * Remove a malloc type from the system.. 800 */ 801 void 802 malloc_type_detach(struct malloc_type *type) 803 { 804 struct malloc_type *ksp; 805 806 #ifdef DIAGNOSTIC 807 if (type->ks_magic != M_MAGIC) 808 panic("malloc_type_detach: bad magic"); 809 #endif 810 811 if (type == kmemstatistics) 812 kmemstatistics = type->ks_next; 813 else { 814 for (ksp = kmemstatistics; ksp->ks_next != NULL; 815 ksp = ksp->ks_next) { 816 if (ksp->ks_next == type) { 817 ksp->ks_next = type->ks_next; 818 break; 819 } 820 } 821 #ifdef DIAGNOSTIC 822 if (ksp->ks_next == NULL) 823 panic("malloc_type_detach: not on list"); 824 #endif 825 } 826 type->ks_next = NULL; 827 } 828 829 /* 830 * Set the limit on a malloc type. 831 */ 832 void 833 malloc_type_setlimit(struct malloc_type *type, u_long limit) 834 { 835 #ifdef KMEMSTATS 836 mutex_spin_enter(&malloc_lock); 837 type->ks_limit = limit; 838 mutex_spin_exit(&malloc_lock); 839 #endif 840 } 841 842 /* 843 * Compute the number of pages that kmem_map will map, that is, 844 * the size of the kernel malloc arena. 845 */ 846 void 847 kmeminit_nkmempages(void) 848 { 849 int npages; 850 851 if (nkmempages != 0) { 852 /* 853 * It's already been set (by us being here before, or 854 * by patching or kernel config options), bail out now. 855 */ 856 return; 857 } 858 859 npages = physmem; 860 861 if (npages > NKMEMPAGES_MAX) 862 npages = NKMEMPAGES_MAX; 863 864 if (npages < NKMEMPAGES_MIN) 865 npages = NKMEMPAGES_MIN; 866 867 nkmempages = npages; 868 } 869 870 /* 871 * Initialize the kernel memory allocator 872 */ 873 void 874 kmeminit(void) 875 { 876 __link_set_decl(malloc_types, struct malloc_type); 877 struct malloc_type * const *ksp; 878 vaddr_t kmb, kml; 879 #ifdef KMEMSTATS 880 long indx; 881 #endif 882 883 #if ((MAXALLOCSAVE & (MAXALLOCSAVE - 1)) != 0) 884 ERROR!_kmeminit:_MAXALLOCSAVE_not_power_of_2 885 #endif 886 #if (MAXALLOCSAVE > MINALLOCSIZE * 32768) 887 ERROR!_kmeminit:_MAXALLOCSAVE_too_big 888 #endif 889 #if (MAXALLOCSAVE < NBPG) 890 ERROR!_kmeminit:_MAXALLOCSAVE_too_small 891 #endif 892 893 if (sizeof(struct freelist) > (1 << MINBUCKET)) 894 panic("minbucket too small/struct freelist too big"); 895 896 mutex_init(&malloc_lock, MUTEX_DEFAULT, IPL_VM); 897 898 /* 899 * Compute the number of kmem_map pages, if we have not 900 * done so already. 901 */ 902 kmeminit_nkmempages(); 903 904 kmemusage = (struct kmemusage *) uvm_km_alloc(kernel_map, 905 (vsize_t)(nkmempages * sizeof(struct kmemusage)), 0, 906 UVM_KMF_WIRED|UVM_KMF_ZERO); 907 kmb = 0; 908 kmem_map = uvm_km_suballoc(kernel_map, &kmb, 909 &kml, ((vsize_t)nkmempages << PAGE_SHIFT), 910 VM_MAP_INTRSAFE, false, &kmem_map_store); 911 uvm_km_vacache_init(kmem_map, "kvakmem", 0); 912 kmembase = (char *)kmb; 913 kmemlimit = (char *)kml; 914 #ifdef KMEMSTATS 915 for (indx = 0; indx < MINBUCKET + 16; indx++) { 916 if (1 << indx >= PAGE_SIZE) 917 kmembuckets[indx].kb_elmpercl = 1; 918 else 919 kmembuckets[indx].kb_elmpercl = PAGE_SIZE / (1 << indx); 920 kmembuckets[indx].kb_highwat = 921 5 * kmembuckets[indx].kb_elmpercl; 922 } 923 #endif 924 925 /* Attach all of the statically-linked malloc types. */ 926 __link_set_foreach(ksp, malloc_types) 927 malloc_type_attach(*ksp); 928 } 929 930 #ifdef DDB 931 #include <ddb/db_output.h> 932 933 /* 934 * Dump kmem statistics from ddb. 935 * 936 * usage: call dump_kmemstats 937 */ 938 void dump_kmemstats(void); 939 940 void 941 dump_kmemstats(void) 942 { 943 #ifdef KMEMSTATS 944 struct malloc_type *ksp; 945 946 for (ksp = kmemstatistics; ksp != NULL; ksp = ksp->ks_next) { 947 if (ksp->ks_memuse == 0) 948 continue; 949 db_printf("%s%.*s %ld\n", ksp->ks_shortdesc, 950 (int)(20 - strlen(ksp->ks_shortdesc)), 951 " ", 952 ksp->ks_memuse); 953 } 954 #else 955 db_printf("Kmem stats are not being collected.\n"); 956 #endif /* KMEMSTATS */ 957 } 958 #endif /* DDB */ 959 960 961 #if 0 962 /* 963 * Diagnostic messages about "Data modified on 964 * freelist" indicate a memory corruption, but 965 * they do not help tracking it down. 966 * This function can be called at various places 967 * to sanity check malloc's freelist and discover 968 * where does the corruption take place. 969 */ 970 int 971 freelist_sanitycheck(void) { 972 int i,j; 973 struct kmembuckets *kbp; 974 struct freelist *freep; 975 int rv = 0; 976 977 for (i = MINBUCKET; i <= MINBUCKET + 15; i++) { 978 kbp = &kmembuckets[i]; 979 freep = (struct freelist *)kbp->kb_next; 980 j = 0; 981 while(freep) { 982 vm_map_lock(kmem_map); 983 rv = uvm_map_checkprot(kmem_map, (vaddr_t)freep, 984 (vaddr_t)freep + sizeof(struct freelist), 985 VM_PROT_WRITE); 986 vm_map_unlock(kmem_map); 987 988 if ((rv == 0) || (*(int *)freep != WEIRD_ADDR)) { 989 printf("bucket %i, chunck %d at %p modified\n", 990 i, j, freep); 991 return 1; 992 } 993 freep = (struct freelist *)freep->next; 994 j++; 995 } 996 } 997 998 return 0; 999 } 1000 #endif 1001