kern_malloc.c revision 1.85
1 /* $NetBSD: kern_malloc.c,v 1.85 2003/08/31 12:59:05 fvdl 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 1.85 2003/08/31 12:59:05 fvdl 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 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 if (malloclog[l].addr == a && malloclog[l].action) { \ 162 lp = &malloclog[l]; \ 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 } 179 #endif /* MALLOCLOG */ 180 181 #ifdef DIAGNOSTIC 182 /* 183 * This structure provides a set of masks to catch unaligned frees. 184 */ 185 const long addrmask[] = { 0, 186 0x00000001, 0x00000003, 0x00000007, 0x0000000f, 187 0x0000001f, 0x0000003f, 0x0000007f, 0x000000ff, 188 0x000001ff, 0x000003ff, 0x000007ff, 0x00000fff, 189 0x00001fff, 0x00003fff, 0x00007fff, 0x0000ffff, 190 }; 191 192 /* 193 * The WEIRD_ADDR is used as known text to copy into free objects so 194 * that modifications after frees can be detected. 195 */ 196 #define WEIRD_ADDR ((uint32_t) 0xdeadbeef) 197 #ifdef DEBUG 198 #define MAX_COPY PAGE_SIZE 199 #else 200 #define MAX_COPY 32 201 #endif 202 203 /* 204 * Normally the freelist structure is used only to hold the list pointer 205 * for free objects. However, when running with diagnostics, the first 206 * 8/16 bytes of the structure is unused except for diagnostic information, 207 * and the free list pointer is at offset 8/16 in the structure. Since the 208 * first 8 bytes is the portion of the structure most often modified, this 209 * helps to detect memory reuse problems and avoid free list corruption. 210 */ 211 struct freelist { 212 uint32_t spare0; 213 #ifdef _LP64 214 uint32_t spare1; /* explicit padding */ 215 #endif 216 struct malloc_type *type; 217 caddr_t next; 218 }; 219 #else /* !DIAGNOSTIC */ 220 struct freelist { 221 caddr_t next; 222 }; 223 #endif /* DIAGNOSTIC */ 224 225 /* 226 * The following are standard, build-in malloc types are are not 227 * specific to any one subsystem. 228 */ 229 MALLOC_DEFINE(M_DEVBUF, "devbuf", "device driver memory"); 230 MALLOC_DEFINE(M_DMAMAP, "DMA map", "bus_dma(9) structures"); 231 MALLOC_DEFINE(M_FREE, "free", "should be on free list"); 232 MALLOC_DEFINE(M_PCB, "pcb", "protocol control block"); 233 MALLOC_DEFINE(M_SOFTINTR, "softintr", "Softinterrupt structures"); 234 MALLOC_DEFINE(M_TEMP, "temp", "misc. temporary data buffers"); 235 236 /* XXX These should all be elsewhere. */ 237 MALLOC_DEFINE(M_RTABLE, "routetbl", "routing tables"); 238 MALLOC_DEFINE(M_FTABLE, "fragtbl", "fragment reassembly header"); 239 MALLOC_DEFINE(M_UFSMNT, "UFS mount", "UFS mount structure"); 240 MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure"); 241 MALLOC_DEFINE(M_IPMOPTS, "ip_moptions", "internet multicast options"); 242 MALLOC_DEFINE(M_IPMADDR, "in_multi", "internet multicast address"); 243 MALLOC_DEFINE(M_MRTABLE, "mrt", "multicast routing tables"); 244 MALLOC_DEFINE(M_1394DATA, "1394data", "IEEE 1394 data buffers"); 245 246 struct simplelock malloc_slock = SIMPLELOCK_INITIALIZER; 247 248 /* 249 * Allocate a block of memory 250 */ 251 #ifdef MALLOCLOG 252 void * 253 _malloc(unsigned long size, struct malloc_type *ksp, int flags, 254 const char *file, long line) 255 #else 256 void * 257 malloc(unsigned long size, struct malloc_type *ksp, int flags) 258 #endif /* MALLOCLOG */ 259 { 260 struct kmembuckets *kbp; 261 struct kmemusage *kup; 262 struct freelist *freep; 263 long indx, npg, allocsize; 264 int s; 265 caddr_t va, cp, savedlist; 266 #ifdef DIAGNOSTIC 267 uint32_t *end, *lp; 268 int copysize; 269 const char *savedtype; 270 #endif 271 272 #ifdef LOCKDEBUG 273 if ((flags & M_NOWAIT) == 0) 274 simple_lock_only_held(NULL, "malloc"); 275 #endif 276 #ifdef MALLOC_DEBUG 277 if (debug_malloc(size, ksp, flags, (void **) &va)) 278 return ((void *) va); 279 #endif 280 indx = BUCKETINDX(size); 281 kbp = &bucket[indx]; 282 s = splvm(); 283 simple_lock(&malloc_slock); 284 #ifdef KMEMSTATS 285 while (ksp->ks_memuse >= ksp->ks_limit) { 286 if (flags & M_NOWAIT) { 287 simple_unlock(&malloc_slock); 288 splx(s); 289 return ((void *) NULL); 290 } 291 if (ksp->ks_limblocks < 65535) 292 ksp->ks_limblocks++; 293 ltsleep((caddr_t)ksp, PSWP+2, ksp->ks_shortdesc, 0, 294 &malloc_slock); 295 } 296 ksp->ks_size |= 1 << indx; 297 #endif 298 #ifdef DIAGNOSTIC 299 copysize = 1 << indx < MAX_COPY ? 1 << indx : MAX_COPY; 300 #endif 301 if (kbp->kb_next == NULL) { 302 kbp->kb_last = NULL; 303 if (size > MAXALLOCSAVE) 304 allocsize = round_page(size); 305 else 306 allocsize = 1 << indx; 307 npg = btoc(allocsize); 308 simple_unlock(&malloc_slock); 309 va = (caddr_t) uvm_km_kmemalloc(kmem_map, NULL, 310 (vsize_t)ctob(npg), 311 ((flags & M_NOWAIT) ? UVM_KMF_NOWAIT : 0) | 312 ((flags & M_CANFAIL) ? UVM_KMF_CANFAIL : 0)); 313 if (__predict_false(va == NULL)) { 314 /* 315 * Kmem_malloc() can return NULL, even if it can 316 * wait, if there is no map space avaiable, because 317 * it can't fix that problem. Neither can we, 318 * right now. (We should release pages which 319 * are completely free and which are in buckets 320 * with too many free elements.) 321 */ 322 if ((flags & (M_NOWAIT|M_CANFAIL)) == 0) 323 panic("malloc: out of space in kmem_map"); 324 splx(s); 325 return (NULL); 326 } 327 simple_lock(&malloc_slock); 328 #ifdef KMEMSTATS 329 kbp->kb_total += kbp->kb_elmpercl; 330 #endif 331 kup = btokup(va); 332 kup->ku_indx = indx; 333 if (allocsize > MAXALLOCSAVE) { 334 if (npg > 65535) 335 panic("malloc: allocation too large"); 336 kup->ku_pagecnt = npg; 337 #ifdef KMEMSTATS 338 ksp->ks_memuse += allocsize; 339 #endif 340 goto out; 341 } 342 #ifdef KMEMSTATS 343 kup->ku_freecnt = kbp->kb_elmpercl; 344 kbp->kb_totalfree += kbp->kb_elmpercl; 345 #endif 346 /* 347 * Just in case we blocked while allocating memory, 348 * and someone else also allocated memory for this 349 * bucket, don't assume the list is still empty. 350 */ 351 savedlist = kbp->kb_next; 352 kbp->kb_next = cp = va + (npg << PAGE_SHIFT) - allocsize; 353 for (;;) { 354 freep = (struct freelist *)cp; 355 #ifdef DIAGNOSTIC 356 /* 357 * Copy in known text to detect modification 358 * after freeing. 359 */ 360 end = (int32_t *)&cp[copysize]; 361 for (lp = (int32_t *)cp; lp < end; lp++) 362 *lp = WEIRD_ADDR; 363 freep->type = M_FREE; 364 #endif /* DIAGNOSTIC */ 365 if (cp <= va) 366 break; 367 cp -= allocsize; 368 freep->next = cp; 369 } 370 freep->next = savedlist; 371 if (kbp->kb_last == NULL) 372 kbp->kb_last = (caddr_t)freep; 373 } 374 va = kbp->kb_next; 375 kbp->kb_next = ((struct freelist *)va)->next; 376 #ifdef DIAGNOSTIC 377 freep = (struct freelist *)va; 378 /* XXX potential to get garbage pointer here. */ 379 savedtype = freep->type->ks_shortdesc; 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 = (int32_t *)&freep->next + 410 (sizeof(freep->next) / sizeof(int32_t)); 411 for (lp = (int32_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 = (int32_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 /* 803 * We use the following (simple) formula: 804 * 805 * - Starting point is physical memory / 4. 806 * 807 * - Clamp it down to NKMEMPAGES_MAX. 808 * 809 * - Round it up to NKMEMPAGES_MIN. 810 */ 811 npages = physmem / 4; 812 813 if (npages > NKMEMPAGES_MAX) 814 npages = NKMEMPAGES_MAX; 815 816 if (npages < NKMEMPAGES_MIN) 817 npages = NKMEMPAGES_MIN; 818 819 nkmempages = npages; 820 } 821 822 /* 823 * Initialize the kernel memory allocator 824 */ 825 void 826 kmeminit(void) 827 { 828 __link_set_decl(malloc_types, struct malloc_type); 829 struct malloc_type * const *ksp; 830 vaddr_t kmb, kml; 831 #ifdef KMEMSTATS 832 long indx; 833 #endif 834 835 #if ((MAXALLOCSAVE & (MAXALLOCSAVE - 1)) != 0) 836 ERROR!_kmeminit:_MAXALLOCSAVE_not_power_of_2 837 #endif 838 #if (MAXALLOCSAVE > MINALLOCSIZE * 32768) 839 ERROR!_kmeminit:_MAXALLOCSAVE_too_big 840 #endif 841 #if (MAXALLOCSAVE < NBPG) 842 ERROR!_kmeminit:_MAXALLOCSAVE_too_small 843 #endif 844 845 if (sizeof(struct freelist) > (1 << MINBUCKET)) 846 panic("minbucket too small/struct freelist too big"); 847 848 /* 849 * Compute the number of kmem_map pages, if we have not 850 * done so already. 851 */ 852 kmeminit_nkmempages(); 853 854 kmemusage = (struct kmemusage *) uvm_km_zalloc(kernel_map, 855 (vsize_t)(nkmempages * sizeof(struct kmemusage))); 856 kmb = 0; 857 kmem_map = uvm_km_suballoc(kernel_map, &kmb, 858 &kml, (vsize_t)(nkmempages << PAGE_SHIFT), 859 VM_MAP_INTRSAFE, FALSE, &kmem_map_store); 860 kmembase = (char *)kmb; 861 kmemlimit = (char *)kml; 862 #ifdef KMEMSTATS 863 for (indx = 0; indx < MINBUCKET + 16; indx++) { 864 if (1 << indx >= PAGE_SIZE) 865 bucket[indx].kb_elmpercl = 1; 866 else 867 bucket[indx].kb_elmpercl = PAGE_SIZE / (1 << indx); 868 bucket[indx].kb_highwat = 5 * bucket[indx].kb_elmpercl; 869 } 870 #endif 871 872 /* Attach all of the statically-linked malloc types. */ 873 __link_set_foreach(ksp, malloc_types) 874 malloc_type_attach(*ksp); 875 876 #ifdef MALLOC_DEBUG 877 debug_malloc_init(); 878 #endif 879 } 880 881 #ifdef DDB 882 #include <ddb/db_output.h> 883 884 /* 885 * Dump kmem statistics from ddb. 886 * 887 * usage: call dump_kmemstats 888 */ 889 void dump_kmemstats(void); 890 891 void 892 dump_kmemstats(void) 893 { 894 #ifdef KMEMSTATS 895 struct malloc_type *ksp; 896 897 for (ksp = kmemstatistics; ksp != NULL; ksp = ksp->ks_next) { 898 if (ksp->ks_memuse == 0) 899 continue; 900 db_printf("%s%.*s %ld\n", ksp->ks_shortdesc, 901 (int)(20 - strlen(ksp->ks_shortdesc)), 902 " ", 903 ksp->ks_memuse); 904 } 905 #else 906 db_printf("Kmem stats are not being collected.\n"); 907 #endif /* KMEMSTATS */ 908 } 909 #endif /* DDB */ 910 911 912 #if 0 913 /* 914 * Diagnostic messages about "Data modified on 915 * freelist" indicate a memory corruption, but 916 * they do not help tracking it down. 917 * This function can be called at various places 918 * to sanity check malloc's freelist and discover 919 * where does the corruption take place. 920 */ 921 int 922 freelist_sanitycheck(void) { 923 int i,j; 924 struct kmembuckets *kbp; 925 struct freelist *freep; 926 int rv = 0; 927 928 for (i = MINBUCKET; i <= MINBUCKET + 15; i++) { 929 kbp = &bucket[i]; 930 freep = (struct freelist *)kbp->kb_next; 931 j = 0; 932 while(freep) { 933 vm_map_lock(kmem_map); 934 rv = uvm_map_checkprot(kmem_map, (vaddr_t)freep, 935 (vaddr_t)freep + sizeof(struct freelist), 936 VM_PROT_WRITE); 937 vm_map_unlock(kmem_map); 938 939 if ((rv == 0) || (*(int *)freep != WEIRD_ADDR)) { 940 printf("bucket %i, chunck %d at %p modified\n", 941 i, j, freep); 942 return 1; 943 } 944 freep = (struct freelist *)freep->next; 945 j++; 946 } 947 } 948 949 return 0; 950 } 951 #endif 952
Indexes created Sat Sep 20 22:09:52 GMT 2025