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sys/kern/kern_malloc.c
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1 /* $NetBSD: kern_malloc.c,v 1.96 2005/02/26 21:34:55 perry 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 1.96 2005/02/26 21:34:55 perry Exp $"); 70 71 #include "opt_lockdebug.h" 72 73 #include <sys/param.h> 74 #include <sys/proc.h> 75 #include <sys/kernel.h> 76 #include <sys/malloc.h> 77 #include <sys/systm.h> 78 79 #include <uvm/uvm_extern.h> 80 81 static struct vm_map_kernel kmem_map_store; 82 struct vm_map *kmem_map = NULL; 83 84 #include "opt_kmempages.h" 85 86 #ifdef NKMEMCLUSTERS 87 #error NKMEMCLUSTERS is obsolete; remove it from your kernel config file and use NKMEMPAGES instead or let the kernel auto-size 88 #endif 89 90 /* 91 * Default number of pages in kmem_map. We attempt to calculate this 92 * at run-time, but allow it to be either patched or set in the kernel 93 * config file. 94 */ 95 #ifndef NKMEMPAGES 96 #define NKMEMPAGES 0 97 #endif 98 int nkmempages = NKMEMPAGES; 99 100 /* 101 * Defaults for lower- and upper-bounds for the kmem_map page count. 102 * Can be overridden by kernel config options. 103 */ 104 #ifndef NKMEMPAGES_MIN 105 #define NKMEMPAGES_MIN NKMEMPAGES_MIN_DEFAULT 106 #endif 107 108 #ifndef NKMEMPAGES_MAX 109 #define NKMEMPAGES_MAX NKMEMPAGES_MAX_DEFAULT 110 #endif 111 112 #include "opt_kmemstats.h" 113 #include "opt_malloclog.h" 114 #include "opt_malloc_debug.h" 115 116 struct kmembuckets bucket[MINBUCKET + 16]; 117 struct kmemusage *kmemusage; 118 char *kmembase, *kmemlimit; 119 120 struct malloc_type *kmemstatistics; 121 122 #ifdef MALLOCLOG 123 #ifndef MALLOCLOGSIZE 124 #define MALLOCLOGSIZE 100000 125 #endif 126 127 struct malloclog { 128 void *addr; 129 long size; 130 struct malloc_type *type; 131 int action; 132 const char *file; 133 long line; 134 } malloclog[MALLOCLOGSIZE]; 135 136 long malloclogptr; 137 138 static void 139 domlog(void *a, long size, struct malloc_type *type, int action, 140 const char *file, long line) 141 { 142 143 malloclog[malloclogptr].addr = a; 144 malloclog[malloclogptr].size = size; 145 malloclog[malloclogptr].type = type; 146 malloclog[malloclogptr].action = action; 147 malloclog[malloclogptr].file = file; 148 malloclog[malloclogptr].line = line; 149 malloclogptr++; 150 if (malloclogptr >= MALLOCLOGSIZE) 151 malloclogptr = 0; 152 } 153 154 static void 155 hitmlog(void *a) 156 { 157 struct malloclog *lp; 158 long l; 159 160 #define PRT do { \ 161 lp = &malloclog[l]; \ 162 if (lp->addr == a && lp->action) { \ 163 printf("malloc log entry %ld:\n", l); \ 164 printf("\taddr = %p\n", lp->addr); \ 165 printf("\tsize = %ld\n", lp->size); \ 166 printf("\ttype = %s\n", lp->type->ks_shortdesc); \ 167 printf("\taction = %s\n", lp->action == 1 ? "alloc" : "free"); \ 168 printf("\tfile = %s\n", lp->file); \ 169 printf("\tline = %ld\n", lp->line); \ 170 } \ 171 } while (/* CONSTCOND */0) 172 173 for (l = malloclogptr; l < MALLOCLOGSIZE; l++) 174 PRT; 175 176 for (l = 0; l < malloclogptr; l++) 177 PRT; 178 #undef PRT 179 } 180 #endif /* MALLOCLOG */ 181 182 #ifdef DIAGNOSTIC 183 /* 184 * This structure provides a set of masks to catch unaligned frees. 185 */ 186 const long addrmask[] = { 0, 187 0x00000001, 0x00000003, 0x00000007, 0x0000000f, 188 0x0000001f, 0x0000003f, 0x0000007f, 0x000000ff, 189 0x000001ff, 0x000003ff, 0x000007ff, 0x00000fff, 190 0x00001fff, 0x00003fff, 0x00007fff, 0x0000ffff, 191 }; 192 193 /* 194 * The WEIRD_ADDR is used as known text to copy into free objects so 195 * that modifications after frees can be detected. 196 */ 197 #define WEIRD_ADDR ((uint32_t) 0xdeadbeef) 198 #ifdef DEBUG 199 #define MAX_COPY PAGE_SIZE 200 #else 201 #define MAX_COPY 32 202 #endif 203 204 /* 205 * Normally the freelist structure is used only to hold the list pointer 206 * for free objects. However, when running with diagnostics, the first 207 * 8/16 bytes of the structure is unused except for diagnostic information, 208 * and the free list pointer is at offset 8/16 in the structure. Since the 209 * first 8 bytes is the portion of the structure most often modified, this 210 * helps to detect memory reuse problems and avoid free list corruption. 211 */ 212 struct freelist { 213 uint32_t spare0; 214 #ifdef _LP64 215 uint32_t spare1; /* explicit padding */ 216 #endif 217 struct malloc_type *type; 218 caddr_t next; 219 }; 220 #else /* !DIAGNOSTIC */ 221 struct freelist { 222 caddr_t next; 223 }; 224 #endif /* DIAGNOSTIC */ 225 226 /* 227 * The following are standard, build-in malloc types are are not 228 * specific to any one subsystem. 229 */ 230 MALLOC_DEFINE(M_DEVBUF, "devbuf", "device driver memory"); 231 MALLOC_DEFINE(M_DMAMAP, "DMA map", "bus_dma(9) structures"); 232 MALLOC_DEFINE(M_FREE, "free", "should be on free list"); 233 MALLOC_DEFINE(M_PCB, "pcb", "protocol control block"); 234 MALLOC_DEFINE(M_SOFTINTR, "softintr", "Softinterrupt structures"); 235 MALLOC_DEFINE(M_TEMP, "temp", "misc. temporary data buffers"); 236 237 /* XXX These should all be elsewhere. */ 238 MALLOC_DEFINE(M_RTABLE, "routetbl", "routing tables"); 239 MALLOC_DEFINE(M_FTABLE, "fragtbl", "fragment reassembly header"); 240 MALLOC_DEFINE(M_UFSMNT, "UFS mount", "UFS mount structure"); 241 MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure"); 242 MALLOC_DEFINE(M_IPMOPTS, "ip_moptions", "internet multicast options"); 243 MALLOC_DEFINE(M_IPMADDR, "in_multi", "internet multicast address"); 244 MALLOC_DEFINE(M_MRTABLE, "mrt", "multicast routing tables"); 245 MALLOC_DEFINE(M_BWMETER, "bwmeter", "multicast upcall bw meters"); 246 MALLOC_DEFINE(M_1394DATA, "1394data", "IEEE 1394 data buffers"); 247 248 struct simplelock malloc_slock = SIMPLELOCK_INITIALIZER; 249 250 /* 251 * Allocate a block of memory 252 */ 253 #ifdef MALLOCLOG 254 void * 255 _malloc(unsigned long size, struct malloc_type *ksp, int flags, 256 const char *file, long line) 257 #else 258 void * 259 malloc(unsigned long size, struct malloc_type *ksp, int flags) 260 #endif /* MALLOCLOG */ 261 { 262 struct kmembuckets *kbp; 263 struct kmemusage *kup; 264 struct freelist *freep; 265 long indx, npg, allocsize; 266 int s; 267 caddr_t va, cp, savedlist; 268 #ifdef DIAGNOSTIC 269 uint32_t *end, *lp; 270 int copysize; 271 #endif 272 273 #ifdef LOCKDEBUG 274 if ((flags & M_NOWAIT) == 0) 275 simple_lock_only_held(NULL, "malloc"); 276 #endif 277 #ifdef MALLOC_DEBUG 278 if (debug_malloc(size, ksp, flags, (void *) &va)) 279 return ((void *) va); 280 #endif 281 indx = BUCKETINDX(size); 282 kbp = &bucket[indx]; 283 s = splvm(); 284 simple_lock(&malloc_slock); 285 #ifdef KMEMSTATS 286 while (ksp->ks_memuse >= ksp->ks_limit) { 287 if (flags & M_NOWAIT) { 288 simple_unlock(&malloc_slock); 289 splx(s); 290 return ((void *) NULL); 291 } 292 if (ksp->ks_limblocks < 65535) 293 ksp->ks_limblocks++; 294 ltsleep((caddr_t)ksp, PSWP+2, ksp->ks_shortdesc, 0, 295 &malloc_slock); 296 } 297 ksp->ks_size |= 1 << indx; 298 #endif 299 #ifdef DIAGNOSTIC 300 copysize = 1 << indx < MAX_COPY ? 1 << indx : MAX_COPY; 301 #endif 302 if (kbp->kb_next == NULL) { 303 kbp->kb_last = NULL; 304 if (size > MAXALLOCSAVE) 305 allocsize = round_page(size); 306 else 307 allocsize = 1 << indx; 308 npg = btoc(allocsize); 309 simple_unlock(&malloc_slock); 310 va = (caddr_t) uvm_km_kmemalloc(kmem_map, NULL, 311 (vsize_t)ctob(npg), 312 ((flags & M_NOWAIT) ? UVM_KMF_NOWAIT : 0) | 313 ((flags & M_CANFAIL) ? UVM_KMF_CANFAIL : 0)); 314 if (__predict_false(va == NULL)) { 315 /* 316 * Kmem_malloc() can return NULL, even if it can 317 * wait, if there is no map space available, because 318 * it can't fix that problem. Neither can we, 319 * right now. (We should release pages which 320 * are completely free and which are in buckets 321 * with too many free elements.) 322 */ 323 if ((flags & (M_NOWAIT|M_CANFAIL)) == 0) 324 panic("malloc: out of space in kmem_map"); 325 splx(s); 326 return (NULL); 327 } 328 simple_lock(&malloc_slock); 329 #ifdef KMEMSTATS 330 kbp->kb_total += kbp->kb_elmpercl; 331 #endif 332 kup = btokup(va); 333 kup->ku_indx = indx; 334 if (allocsize > MAXALLOCSAVE) { 335 if (npg > 65535) 336 panic("malloc: allocation too large"); 337 kup->ku_pagecnt = npg; 338 #ifdef KMEMSTATS 339 ksp->ks_memuse += allocsize; 340 #endif 341 goto out; 342 } 343 #ifdef KMEMSTATS 344 kup->ku_freecnt = kbp->kb_elmpercl; 345 kbp->kb_totalfree += kbp->kb_elmpercl; 346 #endif 347 /* 348 * Just in case we blocked while allocating memory, 349 * and someone else also allocated memory for this 350 * bucket, don't assume the list is still empty. 351 */ 352 savedlist = kbp->kb_next; 353 kbp->kb_next = cp = va + (npg << PAGE_SHIFT) - allocsize; 354 for (;;) { 355 freep = (struct freelist *)cp; 356 #ifdef DIAGNOSTIC 357 /* 358 * Copy in known text to detect modification 359 * after freeing. 360 */ 361 end = (uint32_t *)&cp[copysize]; 362 for (lp = (uint32_t *)cp; lp < end; lp++) 363 *lp = WEIRD_ADDR; 364 freep->type = M_FREE; 365 #endif /* DIAGNOSTIC */ 366 if (cp <= va) 367 break; 368 cp -= allocsize; 369 freep->next = cp; 370 } 371 freep->next = savedlist; 372 if (kbp->kb_last == NULL) 373 kbp->kb_last = (caddr_t)freep; 374 } 375 va = kbp->kb_next; 376 kbp->kb_next = ((struct freelist *)va)->next; 377 #ifdef DIAGNOSTIC 378 freep = (struct freelist *)va; 379 /* XXX potential to get garbage pointer here. */ 380 if (kbp->kb_next) { 381 int rv; 382 vaddr_t addr = (vaddr_t)kbp->kb_next; 383 384 vm_map_lock(kmem_map); 385 rv = uvm_map_checkprot(kmem_map, addr, 386 addr + sizeof(struct freelist), VM_PROT_WRITE); 387 vm_map_unlock(kmem_map); 388 389 if (__predict_false(rv == 0)) { 390 printf("Data modified on freelist: " 391 "word %ld of object %p size %ld previous type %s " 392 "(invalid addr %p)\n", 393 (long)((int32_t *)&kbp->kb_next - (int32_t *)kbp), 394 va, size, "foo", kbp->kb_next); 395 #ifdef MALLOCLOG 396 hitmlog(va); 397 #endif 398 kbp->kb_next = NULL; 399 } 400 } 401 402 /* Fill the fields that we've used with WEIRD_ADDR */ 403 #ifdef _LP64 404 freep->type = (struct malloc_type *) 405 (WEIRD_ADDR | (((u_long) WEIRD_ADDR) << 32)); 406 #else 407 freep->type = (struct malloc_type *) WEIRD_ADDR; 408 #endif 409 end = (uint32_t *)&freep->next + 410 (sizeof(freep->next) / sizeof(int32_t)); 411 for (lp = (uint32_t *)&freep->next; lp < end; lp++) 412 *lp = WEIRD_ADDR; 413 414 /* and check that the data hasn't been modified. */ 415 end = (uint32_t *)&va[copysize]; 416 for (lp = (uint32_t *)va; lp < end; lp++) { 417 if (__predict_true(*lp == WEIRD_ADDR)) 418 continue; 419 printf("Data modified on freelist: " 420 "word %ld of object %p size %ld previous type %s " 421 "(0x%x != 0x%x)\n", 422 (long)(lp - (uint32_t *)va), va, size, 423 "bar", *lp, WEIRD_ADDR); 424 #ifdef MALLOCLOG 425 hitmlog(va); 426 #endif 427 break; 428 } 429 430 freep->spare0 = 0; 431 #endif /* DIAGNOSTIC */ 432 #ifdef KMEMSTATS 433 kup = btokup(va); 434 if (kup->ku_indx != indx) 435 panic("malloc: wrong bucket"); 436 if (kup->ku_freecnt == 0) 437 panic("malloc: lost data"); 438 kup->ku_freecnt--; 439 kbp->kb_totalfree--; 440 ksp->ks_memuse += 1 << indx; 441 out: 442 kbp->kb_calls++; 443 ksp->ks_inuse++; 444 ksp->ks_calls++; 445 if (ksp->ks_memuse > ksp->ks_maxused) 446 ksp->ks_maxused = ksp->ks_memuse; 447 #else 448 out: 449 #endif 450 #ifdef MALLOCLOG 451 domlog(va, size, ksp, 1, file, line); 452 #endif 453 simple_unlock(&malloc_slock); 454 splx(s); 455 if ((flags & M_ZERO) != 0) 456 memset(va, 0, size); 457 return ((void *) va); 458 } 459 460 /* 461 * Free a block of memory allocated by malloc. 462 */ 463 #ifdef MALLOCLOG 464 void 465 _free(void *addr, struct malloc_type *ksp, const char *file, long line) 466 #else 467 void 468 free(void *addr, struct malloc_type *ksp) 469 #endif /* MALLOCLOG */ 470 { 471 struct kmembuckets *kbp; 472 struct kmemusage *kup; 473 struct freelist *freep; 474 long size; 475 int s; 476 #ifdef DIAGNOSTIC 477 caddr_t cp; 478 int32_t *end, *lp; 479 long alloc, copysize; 480 #endif 481 482 #ifdef MALLOC_DEBUG 483 if (debug_free(addr, ksp)) 484 return; 485 #endif 486 487 #ifdef DIAGNOSTIC 488 /* 489 * Ensure that we're free'ing something that we could 490 * have allocated in the first place. That is, check 491 * to see that the address is within kmem_map. 492 */ 493 if (__predict_false((vaddr_t)addr < vm_map_min(kmem_map) || 494 (vaddr_t)addr >= vm_map_max(kmem_map))) 495 panic("free: addr %p not within kmem_map", addr); 496 #endif 497 498 kup = btokup(addr); 499 size = 1 << kup->ku_indx; 500 kbp = &bucket[kup->ku_indx]; 501 s = splvm(); 502 simple_lock(&malloc_slock); 503 #ifdef MALLOCLOG 504 domlog(addr, 0, ksp, 2, file, line); 505 #endif 506 #ifdef DIAGNOSTIC 507 /* 508 * Check for returns of data that do not point to the 509 * beginning of the allocation. 510 */ 511 if (size > PAGE_SIZE) 512 alloc = addrmask[BUCKETINDX(PAGE_SIZE)]; 513 else 514 alloc = addrmask[kup->ku_indx]; 515 if (((u_long)addr & alloc) != 0) 516 panic("free: unaligned addr %p, size %ld, type %s, mask %ld", 517 addr, size, ksp->ks_shortdesc, alloc); 518 #endif /* DIAGNOSTIC */ 519 if (size > MAXALLOCSAVE) { 520 uvm_km_free(kmem_map, (vaddr_t)addr, ctob(kup->ku_pagecnt)); 521 #ifdef KMEMSTATS 522 size = kup->ku_pagecnt << PGSHIFT; 523 ksp->ks_memuse -= size; 524 kup->ku_indx = 0; 525 kup->ku_pagecnt = 0; 526 if (ksp->ks_memuse + size >= ksp->ks_limit && 527 ksp->ks_memuse < ksp->ks_limit) 528 wakeup((caddr_t)ksp); 529 #ifdef DIAGNOSTIC 530 if (ksp->ks_inuse == 0) 531 panic("free 1: inuse 0, probable double free"); 532 #endif 533 ksp->ks_inuse--; 534 kbp->kb_total -= 1; 535 #endif 536 simple_unlock(&malloc_slock); 537 splx(s); 538 return; 539 } 540 freep = (struct freelist *)addr; 541 #ifdef DIAGNOSTIC 542 /* 543 * Check for multiple frees. Use a quick check to see if 544 * it looks free before laboriously searching the freelist. 545 */ 546 if (__predict_false(freep->spare0 == WEIRD_ADDR)) { 547 for (cp = kbp->kb_next; cp; 548 cp = ((struct freelist *)cp)->next) { 549 if (addr != cp) 550 continue; 551 printf("multiply freed item %p\n", addr); 552 #ifdef MALLOCLOG 553 hitmlog(addr); 554 #endif 555 panic("free: duplicated free"); 556 } 557 } 558 #ifdef LOCKDEBUG 559 /* 560 * Check if we're freeing a locked simple lock. 561 */ 562 simple_lock_freecheck(addr, (char *)addr + size); 563 #endif 564 /* 565 * Copy in known text to detect modification after freeing 566 * and to make it look free. Also, save the type being freed 567 * so we can list likely culprit if modification is detected 568 * when the object is reallocated. 569 */ 570 copysize = size < MAX_COPY ? size : MAX_COPY; 571 end = (int32_t *)&((caddr_t)addr)[copysize]; 572 for (lp = (int32_t *)addr; lp < end; lp++) 573 *lp = WEIRD_ADDR; 574 freep->type = ksp; 575 #endif /* DIAGNOSTIC */ 576 #ifdef KMEMSTATS 577 kup->ku_freecnt++; 578 if (kup->ku_freecnt >= kbp->kb_elmpercl) { 579 if (kup->ku_freecnt > kbp->kb_elmpercl) 580 panic("free: multiple frees"); 581 else if (kbp->kb_totalfree > kbp->kb_highwat) 582 kbp->kb_couldfree++; 583 } 584 kbp->kb_totalfree++; 585 ksp->ks_memuse -= size; 586 if (ksp->ks_memuse + size >= ksp->ks_limit && 587 ksp->ks_memuse < ksp->ks_limit) 588 wakeup((caddr_t)ksp); 589 #ifdef DIAGNOSTIC 590 if (ksp->ks_inuse == 0) 591 panic("free 2: inuse 0, probable double free"); 592 #endif 593 ksp->ks_inuse--; 594 #endif 595 if (kbp->kb_next == NULL) 596 kbp->kb_next = addr; 597 else 598 ((struct freelist *)kbp->kb_last)->next = addr; 599 freep->next = NULL; 600 kbp->kb_last = addr; 601 simple_unlock(&malloc_slock); 602 splx(s); 603 } 604 605 /* 606 * Change the size of a block of memory. 607 */ 608 void * 609 realloc(void *curaddr, unsigned long newsize, struct malloc_type *ksp, 610 int flags) 611 { 612 struct kmemusage *kup; 613 unsigned long cursize; 614 void *newaddr; 615 #ifdef DIAGNOSTIC 616 long alloc; 617 #endif 618 619 /* 620 * realloc() with a NULL pointer is the same as malloc(). 621 */ 622 if (curaddr == NULL) 623 return (malloc(newsize, ksp, flags)); 624 625 /* 626 * realloc() with zero size is the same as free(). 627 */ 628 if (newsize == 0) { 629 free(curaddr, ksp); 630 return (NULL); 631 } 632 633 #ifdef LOCKDEBUG 634 if ((flags & M_NOWAIT) == 0) 635 simple_lock_only_held(NULL, "realloc"); 636 #endif 637 638 /* 639 * Find out how large the old allocation was (and do some 640 * sanity checking). 641 */ 642 kup = btokup(curaddr); 643 cursize = 1 << kup->ku_indx; 644 645 #ifdef DIAGNOSTIC 646 /* 647 * Check for returns of data that do not point to the 648 * beginning of the allocation. 649 */ 650 if (cursize > PAGE_SIZE) 651 alloc = addrmask[BUCKETINDX(PAGE_SIZE)]; 652 else 653 alloc = addrmask[kup->ku_indx]; 654 if (((u_long)curaddr & alloc) != 0) 655 panic("realloc: " 656 "unaligned addr %p, size %ld, type %s, mask %ld\n", 657 curaddr, cursize, ksp->ks_shortdesc, alloc); 658 #endif /* DIAGNOSTIC */ 659 660 if (cursize > MAXALLOCSAVE) 661 cursize = ctob(kup->ku_pagecnt); 662 663 /* 664 * If we already actually have as much as they want, we're done. 665 */ 666 if (newsize <= cursize) 667 return (curaddr); 668 669 /* 670 * Can't satisfy the allocation with the existing block. 671 * Allocate a new one and copy the data. 672 */ 673 newaddr = malloc(newsize, ksp, flags); 674 if (__predict_false(newaddr == NULL)) { 675 /* 676 * malloc() failed, because flags included M_NOWAIT. 677 * Return NULL to indicate that failure. The old 678 * pointer is still valid. 679 */ 680 return (NULL); 681 } 682 memcpy(newaddr, curaddr, cursize); 683 684 /* 685 * We were successful: free the old allocation and return 686 * the new one. 687 */ 688 free(curaddr, ksp); 689 return (newaddr); 690 } 691 692 /* 693 * Roundup size to the actual allocation size. 694 */ 695 unsigned long 696 malloc_roundup(unsigned long size) 697 { 698 699 if (size > MAXALLOCSAVE) 700 return (roundup(size, PAGE_SIZE)); 701 else 702 return (1 << BUCKETINDX(size)); 703 } 704 705 /* 706 * Add a malloc type to the system. 707 */ 708 void 709 malloc_type_attach(struct malloc_type *type) 710 { 711 712 if (nkmempages == 0) 713 panic("malloc_type_attach: nkmempages == 0"); 714 715 if (type->ks_magic != M_MAGIC) 716 panic("malloc_type_attach: bad magic"); 717 718 #ifdef DIAGNOSTIC 719 { 720 struct malloc_type *ksp; 721 for (ksp = kmemstatistics; ksp != NULL; ksp = ksp->ks_next) { 722 if (ksp == type) 723 panic("malloc_type_attach: already on list"); 724 } 725 } 726 #endif 727 728 #ifdef KMEMSTATS 729 if (type->ks_limit == 0) 730 type->ks_limit = ((u_long)nkmempages << PAGE_SHIFT) * 6U / 10U; 731 #else 732 type->ks_limit = 0; 733 #endif 734 735 type->ks_next = kmemstatistics; 736 kmemstatistics = type; 737 } 738 739 /* 740 * Remove a malloc type from the system.. 741 */ 742 void 743 malloc_type_detach(struct malloc_type *type) 744 { 745 struct malloc_type *ksp; 746 747 #ifdef DIAGNOSTIC 748 if (type->ks_magic != M_MAGIC) 749 panic("malloc_type_detach: bad magic"); 750 #endif 751 752 if (type == kmemstatistics) 753 kmemstatistics = type->ks_next; 754 else { 755 for (ksp = kmemstatistics; ksp->ks_next != NULL; 756 ksp = ksp->ks_next) { 757 if (ksp->ks_next == type) { 758 ksp->ks_next = type->ks_next; 759 break; 760 } 761 } 762 #ifdef DIAGNOSTIC 763 if (ksp->ks_next == NULL) 764 panic("malloc_type_detach: not on list"); 765 #endif 766 } 767 type->ks_next = NULL; 768 } 769 770 /* 771 * Set the limit on a malloc type. 772 */ 773 void 774 malloc_type_setlimit(struct malloc_type *type, u_long limit) 775 { 776 #ifdef KMEMSTATS 777 int s; 778 779 s = splvm(); 780 type->ks_limit = limit; 781 splx(s); 782 #endif 783 } 784 785 /* 786 * Compute the number of pages that kmem_map will map, that is, 787 * the size of the kernel malloc arena. 788 */ 789 void 790 kmeminit_nkmempages(void) 791 { 792 int npages; 793 794 if (nkmempages != 0) { 795 /* 796 * It's already been set (by us being here before, or 797 * by patching or kernel config options), bail out now. 798 */ 799 return; 800 } 801 802 npages = physmem; 803 804 if (npages > NKMEMPAGES_MAX) 805 npages = NKMEMPAGES_MAX; 806 807 if (npages < NKMEMPAGES_MIN) 808 npages = NKMEMPAGES_MIN; 809 810 nkmempages = npages; 811 } 812 813 /* 814 * Initialize the kernel memory allocator 815 */ 816 void 817 kmeminit(void) 818 { 819 __link_set_decl(malloc_types, struct malloc_type); 820 struct malloc_type * const *ksp; 821 vaddr_t kmb, kml; 822 #ifdef KMEMSTATS 823 long indx; 824 #endif 825 826 #if ((MAXALLOCSAVE & (MAXALLOCSAVE - 1)) != 0) 827 ERROR!_kmeminit:_MAXALLOCSAVE_not_power_of_2 828 #endif 829 #if (MAXALLOCSAVE > MINALLOCSIZE * 32768) 830 ERROR!_kmeminit:_MAXALLOCSAVE_too_big 831 #endif 832 #if (MAXALLOCSAVE < NBPG) 833 ERROR!_kmeminit:_MAXALLOCSAVE_too_small 834 #endif 835 836 if (sizeof(struct freelist) > (1 << MINBUCKET)) 837 panic("minbucket too small/struct freelist too big"); 838 839 /* 840 * Compute the number of kmem_map pages, if we have not 841 * done so already. 842 */ 843 kmeminit_nkmempages(); 844 845 kmemusage = (struct kmemusage *) uvm_km_zalloc(kernel_map, 846 (vsize_t)(nkmempages * sizeof(struct kmemusage))); 847 kmb = 0; 848 kmem_map = uvm_km_suballoc(kernel_map, &kmb, 849 &kml, ((vsize_t)nkmempages << PAGE_SHIFT), 850 VM_MAP_INTRSAFE, FALSE, &kmem_map_store); 851 uvm_km_vacache_init(kmem_map, "kvakmem", 0); 852 kmembase = (char *)kmb; 853 kmemlimit = (char *)kml; 854 #ifdef KMEMSTATS 855 for (indx = 0; indx < MINBUCKET + 16; indx++) { 856 if (1 << indx >= PAGE_SIZE) 857 bucket[indx].kb_elmpercl = 1; 858 else 859 bucket[indx].kb_elmpercl = PAGE_SIZE / (1 << indx); 860 bucket[indx].kb_highwat = 5 * bucket[indx].kb_elmpercl; 861 } 862 #endif 863 864 /* Attach all of the statically-linked malloc types. */ 865 __link_set_foreach(ksp, malloc_types) 866 malloc_type_attach(*ksp); 867 868 #ifdef MALLOC_DEBUG 869 debug_malloc_init(); 870 #endif 871 } 872 873 #ifdef DDB 874 #include <ddb/db_output.h> 875 876 /* 877 * Dump kmem statistics from ddb. 878 * 879 * usage: call dump_kmemstats 880 */ 881 void dump_kmemstats(void); 882 883 void 884 dump_kmemstats(void) 885 { 886 #ifdef KMEMSTATS 887 struct malloc_type *ksp; 888 889 for (ksp = kmemstatistics; ksp != NULL; ksp = ksp->ks_next) { 890 if (ksp->ks_memuse == 0) 891 continue; 892 db_printf("%s%.*s %ld\n", ksp->ks_shortdesc, 893 (int)(20 - strlen(ksp->ks_shortdesc)), 894 " ", 895 ksp->ks_memuse); 896 } 897 #else 898 db_printf("Kmem stats are not being collected.\n"); 899 #endif /* KMEMSTATS */ 900 } 901 #endif /* DDB */ 902 903 904 #if 0 905 /* 906 * Diagnostic messages about "Data modified on 907 * freelist" indicate a memory corruption, but 908 * they do not help tracking it down. 909 * This function can be called at various places 910 * to sanity check malloc's freelist and discover 911 * where does the corruption take place. 912 */ 913 int 914 freelist_sanitycheck(void) { 915 int i,j; 916 struct kmembuckets *kbp; 917 struct freelist *freep; 918 int rv = 0; 919 920 for (i = MINBUCKET; i <= MINBUCKET + 15; i++) { 921 kbp = &bucket[i]; 922 freep = (struct freelist *)kbp->kb_next; 923 j = 0; 924 while(freep) { 925 vm_map_lock(kmem_map); 926 rv = uvm_map_checkprot(kmem_map, (vaddr_t)freep, 927 (vaddr_t)freep + sizeof(struct freelist), 928 VM_PROT_WRITE); 929 vm_map_unlock(kmem_map); 930 931 if ((rv == 0) || (*(int *)freep != WEIRD_ADDR)) { 932 printf("bucket %i, chunck %d at %p modified\n", 933 i, j, freep); 934 return 1; 935 } 936 freep = (struct freelist *)freep->next; 937 j++; 938 } 939 } 940 941 return 0; 942 } 943 #endif
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