kern_malloc.c revision 1.89
1 /* $NetBSD: kern_malloc.c,v 1.89 2003/10/30 01:58:18 simonb 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 1.89 2003/10/30 01:58:18 simonb 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 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_1394DATA, "1394data", "IEEE 1394 data buffers"); 246 247 struct simplelock malloc_slock = SIMPLELOCK_INITIALIZER; 248 249 /* 250 * Allocate a block of memory 251 */ 252 #ifdef MALLOCLOG 253 void * 254 _malloc(unsigned long size, struct malloc_type *ksp, int flags, 255 const char *file, long line) 256 #else 257 void * 258 malloc(unsigned long size, struct malloc_type *ksp, int flags) 259 #endif /* MALLOCLOG */ 260 { 261 struct kmembuckets *kbp; 262 struct kmemusage *kup; 263 struct freelist *freep; 264 long indx, npg, allocsize; 265 int s; 266 caddr_t va, cp, savedlist; 267 #ifdef DIAGNOSTIC 268 uint32_t *end, *lp; 269 int copysize; 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 = (uint32_t *)&cp[copysize]; 361 for (lp = (uint32_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 if (kbp->kb_next) { 380 int rv; 381 vaddr_t addr = (vaddr_t)kbp->kb_next; 382 383 vm_map_lock(kmem_map); 384 rv = uvm_map_checkprot(kmem_map, addr, 385 addr + sizeof(struct freelist), VM_PROT_WRITE); 386 vm_map_unlock(kmem_map); 387 388 if (__predict_false(rv == 0)) { 389 printf("Data modified on freelist: " 390 "word %ld of object %p size %ld previous type %s " 391 "(invalid addr %p)\n", 392 (long)((int32_t *)&kbp->kb_next - (int32_t *)kbp), 393 va, size, "foo", kbp->kb_next); 394 #ifdef MALLOCLOG 395 hitmlog(va); 396 #endif 397 kbp->kb_next = NULL; 398 } 399 } 400 401 /* Fill the fields that we've used with WEIRD_ADDR */ 402 #ifdef _LP64 403 freep->type = (struct malloc_type *) 404 (WEIRD_ADDR | (((u_long) WEIRD_ADDR) << 32)); 405 #else 406 freep->type = (struct malloc_type *) WEIRD_ADDR; 407 #endif 408 end = (uint32_t *)&freep->next + 409 (sizeof(freep->next) / sizeof(int32_t)); 410 for (lp = (uint32_t *)&freep->next; lp < end; lp++) 411 *lp = WEIRD_ADDR; 412 413 /* and check that the data hasn't been modified. */ 414 end = (uint32_t *)&va[copysize]; 415 for (lp = (uint32_t *)va; lp < end; lp++) { 416 if (__predict_true(*lp == WEIRD_ADDR)) 417 continue; 418 printf("Data modified on freelist: " 419 "word %ld of object %p size %ld previous type %s " 420 "(0x%x != 0x%x)\n", 421 (long)(lp - (uint32_t *)va), va, size, 422 "bar", *lp, WEIRD_ADDR); 423 #ifdef MALLOCLOG 424 hitmlog(va); 425 #endif 426 break; 427 } 428 429 freep->spare0 = 0; 430 #endif /* DIAGNOSTIC */ 431 #ifdef KMEMSTATS 432 kup = btokup(va); 433 if (kup->ku_indx != indx) 434 panic("malloc: wrong bucket"); 435 if (kup->ku_freecnt == 0) 436 panic("malloc: lost data"); 437 kup->ku_freecnt--; 438 kbp->kb_totalfree--; 439 ksp->ks_memuse += 1 << indx; 440 out: 441 kbp->kb_calls++; 442 ksp->ks_inuse++; 443 ksp->ks_calls++; 444 if (ksp->ks_memuse > ksp->ks_maxused) 445 ksp->ks_maxused = ksp->ks_memuse; 446 #else 447 out: 448 #endif 449 #ifdef MALLOCLOG 450 domlog(va, size, ksp, 1, file, line); 451 #endif 452 simple_unlock(&malloc_slock); 453 splx(s); 454 if ((flags & M_ZERO) != 0) 455 memset(va, 0, size); 456 return ((void *) va); 457 } 458 459 /* 460 * Free a block of memory allocated by malloc. 461 */ 462 #ifdef MALLOCLOG 463 void 464 _free(void *addr, struct malloc_type *ksp, const char *file, long line) 465 #else 466 void 467 free(void *addr, struct malloc_type *ksp) 468 #endif /* MALLOCLOG */ 469 { 470 struct kmembuckets *kbp; 471 struct kmemusage *kup; 472 struct freelist *freep; 473 long size; 474 int s; 475 #ifdef DIAGNOSTIC 476 caddr_t cp; 477 int32_t *end, *lp; 478 long alloc, copysize; 479 #endif 480 481 #ifdef MALLOC_DEBUG 482 if (debug_free(addr, ksp)) 483 return; 484 #endif 485 486 #ifdef DIAGNOSTIC 487 /* 488 * Ensure that we're free'ing something that we could 489 * have allocated in the first place. That is, check 490 * to see that the address is within kmem_map. 491 */ 492 if (__predict_false((vaddr_t)addr < vm_map_min(kmem_map) || 493 (vaddr_t)addr >= vm_map_max(kmem_map))) 494 panic("free: addr %p not within kmem_map", addr); 495 #endif 496 497 kup = btokup(addr); 498 size = 1 << kup->ku_indx; 499 kbp = &bucket[kup->ku_indx]; 500 s = splvm(); 501 simple_lock(&malloc_slock); 502 #ifdef MALLOCLOG 503 domlog(addr, 0, ksp, 2, file, line); 504 #endif 505 #ifdef DIAGNOSTIC 506 /* 507 * Check for returns of data that do not point to the 508 * beginning of the allocation. 509 */ 510 if (size > PAGE_SIZE) 511 alloc = addrmask[BUCKETINDX(PAGE_SIZE)]; 512 else 513 alloc = addrmask[kup->ku_indx]; 514 if (((u_long)addr & alloc) != 0) 515 panic("free: unaligned addr %p, size %ld, type %s, mask %ld", 516 addr, size, ksp->ks_shortdesc, alloc); 517 #endif /* DIAGNOSTIC */ 518 if (size > MAXALLOCSAVE) { 519 uvm_km_free(kmem_map, (vaddr_t)addr, ctob(kup->ku_pagecnt)); 520 #ifdef KMEMSTATS 521 size = kup->ku_pagecnt << PGSHIFT; 522 ksp->ks_memuse -= size; 523 kup->ku_indx = 0; 524 kup->ku_pagecnt = 0; 525 if (ksp->ks_memuse + size >= ksp->ks_limit && 526 ksp->ks_memuse < ksp->ks_limit) 527 wakeup((caddr_t)ksp); 528 #ifdef DIAGNOSTIC 529 if (ksp->ks_inuse == 0) 530 panic("free 1: inuse 0, probable double free"); 531 #endif 532 ksp->ks_inuse--; 533 kbp->kb_total -= 1; 534 #endif 535 simple_unlock(&malloc_slock); 536 splx(s); 537 return; 538 } 539 freep = (struct freelist *)addr; 540 #ifdef DIAGNOSTIC 541 /* 542 * Check for multiple frees. Use a quick check to see if 543 * it looks free before laboriously searching the freelist. 544 */ 545 if (__predict_false(freep->spare0 == WEIRD_ADDR)) { 546 for (cp = kbp->kb_next; cp; 547 cp = ((struct freelist *)cp)->next) { 548 if (addr != cp) 549 continue; 550 printf("multiply freed item %p\n", addr); 551 #ifdef MALLOCLOG 552 hitmlog(addr); 553 #endif 554 panic("free: duplicated free"); 555 } 556 } 557 #ifdef LOCKDEBUG 558 /* 559 * Check if we're freeing a locked simple lock. 560 */ 561 simple_lock_freecheck(addr, (char *)addr + size); 562 #endif 563 /* 564 * Copy in known text to detect modification after freeing 565 * and to make it look free. Also, save the type being freed 566 * so we can list likely culprit if modification is detected 567 * when the object is reallocated. 568 */ 569 copysize = size < MAX_COPY ? size : MAX_COPY; 570 end = (int32_t *)&((caddr_t)addr)[copysize]; 571 for (lp = (int32_t *)addr; lp < end; lp++) 572 *lp = WEIRD_ADDR; 573 freep->type = ksp; 574 #endif /* DIAGNOSTIC */ 575 #ifdef KMEMSTATS 576 kup->ku_freecnt++; 577 if (kup->ku_freecnt >= kbp->kb_elmpercl) { 578 if (kup->ku_freecnt > kbp->kb_elmpercl) 579 panic("free: multiple frees"); 580 else if (kbp->kb_totalfree > kbp->kb_highwat) 581 kbp->kb_couldfree++; 582 } 583 kbp->kb_totalfree++; 584 ksp->ks_memuse -= size; 585 if (ksp->ks_memuse + size >= ksp->ks_limit && 586 ksp->ks_memuse < ksp->ks_limit) 587 wakeup((caddr_t)ksp); 588 #ifdef DIAGNOSTIC 589 if (ksp->ks_inuse == 0) 590 panic("free 2: inuse 0, probable double free"); 591 #endif 592 ksp->ks_inuse--; 593 #endif 594 if (kbp->kb_next == NULL) 595 kbp->kb_next = addr; 596 else 597 ((struct freelist *)kbp->kb_last)->next = addr; 598 freep->next = NULL; 599 kbp->kb_last = addr; 600 simple_unlock(&malloc_slock); 601 splx(s); 602 } 603 604 /* 605 * Change the size of a block of memory. 606 */ 607 void * 608 realloc(void *curaddr, unsigned long newsize, struct malloc_type *ksp, 609 int flags) 610 { 611 struct kmemusage *kup; 612 unsigned long cursize; 613 void *newaddr; 614 #ifdef DIAGNOSTIC 615 long alloc; 616 #endif 617 618 /* 619 * realloc() with a NULL pointer is the same as malloc(). 620 */ 621 if (curaddr == NULL) 622 return (malloc(newsize, ksp, flags)); 623 624 /* 625 * realloc() with zero size is the same as free(). 626 */ 627 if (newsize == 0) { 628 free(curaddr, ksp); 629 return (NULL); 630 } 631 632 #ifdef LOCKDEBUG 633 if ((flags & M_NOWAIT) == 0) 634 simple_lock_only_held(NULL, "realloc"); 635 #endif 636 637 /* 638 * Find out how large the old allocation was (and do some 639 * sanity checking). 640 */ 641 kup = btokup(curaddr); 642 cursize = 1 << kup->ku_indx; 643 644 #ifdef DIAGNOSTIC 645 /* 646 * Check for returns of data that do not point to the 647 * beginning of the allocation. 648 */ 649 if (cursize > PAGE_SIZE) 650 alloc = addrmask[BUCKETINDX(PAGE_SIZE)]; 651 else 652 alloc = addrmask[kup->ku_indx]; 653 if (((u_long)curaddr & alloc) != 0) 654 panic("realloc: " 655 "unaligned addr %p, size %ld, type %s, mask %ld\n", 656 curaddr, cursize, ksp->ks_shortdesc, alloc); 657 #endif /* DIAGNOSTIC */ 658 659 if (cursize > MAXALLOCSAVE) 660 cursize = ctob(kup->ku_pagecnt); 661 662 /* 663 * If we already actually have as much as they want, we're done. 664 */ 665 if (newsize <= cursize) 666 return (curaddr); 667 668 /* 669 * Can't satisfy the allocation with the existing block. 670 * Allocate a new one and copy the data. 671 */ 672 newaddr = malloc(newsize, ksp, flags); 673 if (__predict_false(newaddr == NULL)) { 674 /* 675 * malloc() failed, because flags included M_NOWAIT. 676 * Return NULL to indicate that failure. The old 677 * pointer is still valid. 678 */ 679 return (NULL); 680 } 681 memcpy(newaddr, curaddr, cursize); 682 683 /* 684 * We were successful: free the old allocation and return 685 * the new one. 686 */ 687 free(curaddr, ksp); 688 return (newaddr); 689 } 690 691 /* 692 * Roundup size to the actual allocation size. 693 */ 694 unsigned long 695 malloc_roundup(unsigned long size) 696 { 697 698 if (size > MAXALLOCSAVE) 699 return (roundup(size, PAGE_SIZE)); 700 else 701 return (1 << BUCKETINDX(size)); 702 } 703 704 /* 705 * Add a malloc type to the system. 706 */ 707 void 708 malloc_type_attach(struct malloc_type *type) 709 { 710 711 if (nkmempages == 0) 712 panic("malloc_type_attach: nkmempages == 0"); 713 714 if (type->ks_magic != M_MAGIC) 715 panic("malloc_type_attach: bad magic"); 716 717 #ifdef DIAGNOSTIC 718 { 719 struct malloc_type *ksp; 720 for (ksp = kmemstatistics; ksp != NULL; ksp = ksp->ks_next) { 721 if (ksp == type) 722 panic("malloc_type_attach: already on list"); 723 } 724 } 725 #endif 726 727 #ifdef KMEMSTATS 728 if (type->ks_limit == 0) 729 type->ks_limit = ((u_long)nkmempages << PAGE_SHIFT) * 6U / 10U; 730 #else 731 type->ks_limit = 0; 732 #endif 733 734 type->ks_next = kmemstatistics; 735 kmemstatistics = type; 736 } 737 738 /* 739 * Remove a malloc type from the system.. 740 */ 741 void 742 malloc_type_detach(struct malloc_type *type) 743 { 744 struct malloc_type *ksp; 745 746 #ifdef DIAGNOSTIC 747 if (type->ks_magic != M_MAGIC) 748 panic("malloc_type_detach: bad magic"); 749 #endif 750 751 if (type == kmemstatistics) 752 kmemstatistics = type->ks_next; 753 else { 754 for (ksp = kmemstatistics; ksp->ks_next != NULL; 755 ksp = ksp->ks_next) { 756 if (ksp->ks_next == type) { 757 ksp->ks_next = type->ks_next; 758 break; 759 } 760 } 761 #ifdef DIAGNOSTIC 762 if (ksp->ks_next == NULL) 763 panic("malloc_type_detach: not on list"); 764 #endif 765 } 766 type->ks_next = NULL; 767 } 768 769 /* 770 * Set the limit on a malloc type. 771 */ 772 void 773 malloc_type_setlimit(struct malloc_type *type, u_long limit) 774 { 775 #ifdef KMEMSTATS 776 int s; 777 778 s = splvm(); 779 type->ks_limit = limit; 780 splx(s); 781 #endif 782 } 783 784 /* 785 * Compute the number of pages that kmem_map will map, that is, 786 * the size of the kernel malloc arena. 787 */ 788 void 789 kmeminit_nkmempages(void) 790 { 791 int npages; 792 793 if (nkmempages != 0) { 794 /* 795 * It's already been set (by us being here before, or 796 * by patching or kernel config options), bail out now. 797 */ 798 return; 799 } 800 801 /* 802 * We use the following (simple) formula: 803 * 804 * - Starting point is physical memory / 4. 805 * 806 * - Clamp it down to NKMEMPAGES_MAX. 807 * 808 * - Round it up to NKMEMPAGES_MIN. 809 */ 810 npages = physmem / 4; 811 812 if (npages > NKMEMPAGES_MAX) 813 npages = NKMEMPAGES_MAX; 814 815 if (npages < NKMEMPAGES_MIN) 816 npages = NKMEMPAGES_MIN; 817 818 nkmempages = npages; 819 } 820 821 /* 822 * Initialize the kernel memory allocator 823 */ 824 void 825 kmeminit(void) 826 { 827 __link_set_decl(malloc_types, struct malloc_type); 828 struct malloc_type * const *ksp; 829 vaddr_t kmb, kml; 830 #ifdef KMEMSTATS 831 long indx; 832 #endif 833 834 #if ((MAXALLOCSAVE & (MAXALLOCSAVE - 1)) != 0) 835 ERROR!_kmeminit:_MAXALLOCSAVE_not_power_of_2 836 #endif 837 #if (MAXALLOCSAVE > MINALLOCSIZE * 32768) 838 ERROR!_kmeminit:_MAXALLOCSAVE_too_big 839 #endif 840 #if (MAXALLOCSAVE < NBPG) 841 ERROR!_kmeminit:_MAXALLOCSAVE_too_small 842 #endif 843 844 if (sizeof(struct freelist) > (1 << MINBUCKET)) 845 panic("minbucket too small/struct freelist too big"); 846 847 /* 848 * Compute the number of kmem_map pages, if we have not 849 * done so already. 850 */ 851 kmeminit_nkmempages(); 852 853 kmemusage = (struct kmemusage *) uvm_km_zalloc(kernel_map, 854 (vsize_t)(nkmempages * sizeof(struct kmemusage))); 855 kmb = 0; 856 kmem_map = uvm_km_suballoc(kernel_map, &kmb, 857 &kml, (vsize_t)(nkmempages << PAGE_SHIFT), 858 VM_MAP_INTRSAFE, FALSE, &kmem_map_store); 859 kmembase = (char *)kmb; 860 kmemlimit = (char *)kml; 861 #ifdef KMEMSTATS 862 for (indx = 0; indx < MINBUCKET + 16; indx++) { 863 if (1 << indx >= PAGE_SIZE) 864 bucket[indx].kb_elmpercl = 1; 865 else 866 bucket[indx].kb_elmpercl = PAGE_SIZE / (1 << indx); 867 bucket[indx].kb_highwat = 5 * bucket[indx].kb_elmpercl; 868 } 869 #endif 870 871 /* Attach all of the statically-linked malloc types. */ 872 __link_set_foreach(ksp, malloc_types) 873 malloc_type_attach(*ksp); 874 875 #ifdef MALLOC_DEBUG 876 debug_malloc_init(); 877 #endif 878 } 879 880 #ifdef DDB 881 #include <ddb/db_output.h> 882 883 /* 884 * Dump kmem statistics from ddb. 885 * 886 * usage: call dump_kmemstats 887 */ 888 void dump_kmemstats(void); 889 890 void 891 dump_kmemstats(void) 892 { 893 #ifdef KMEMSTATS 894 struct malloc_type *ksp; 895 896 for (ksp = kmemstatistics; ksp != NULL; ksp = ksp->ks_next) { 897 if (ksp->ks_memuse == 0) 898 continue; 899 db_printf("%s%.*s %ld\n", ksp->ks_shortdesc, 900 (int)(20 - strlen(ksp->ks_shortdesc)), 901 " ", 902 ksp->ks_memuse); 903 } 904 #else 905 db_printf("Kmem stats are not being collected.\n"); 906 #endif /* KMEMSTATS */ 907 } 908 #endif /* DDB */ 909 910 911 #if 0 912 /* 913 * Diagnostic messages about "Data modified on 914 * freelist" indicate a memory corruption, but 915 * they do not help tracking it down. 916 * This function can be called at various places 917 * to sanity check malloc's freelist and discover 918 * where does the corruption take place. 919 */ 920 int 921 freelist_sanitycheck(void) { 922 int i,j; 923 struct kmembuckets *kbp; 924 struct freelist *freep; 925 int rv = 0; 926 927 for (i = MINBUCKET; i <= MINBUCKET + 15; i++) { 928 kbp = &bucket[i]; 929 freep = (struct freelist *)kbp->kb_next; 930 j = 0; 931 while(freep) { 932 vm_map_lock(kmem_map); 933 rv = uvm_map_checkprot(kmem_map, (vaddr_t)freep, 934 (vaddr_t)freep + sizeof(struct freelist), 935 VM_PROT_WRITE); 936 vm_map_unlock(kmem_map); 937 938 if ((rv == 0) || (*(int *)freep != WEIRD_ADDR)) { 939 printf("bucket %i, chunck %d at %p modified\n", 940 i, j, freep); 941 return 1; 942 } 943 freep = (struct freelist *)freep->next; 944 j++; 945 } 946 } 947 948 return 0; 949 } 950 #endif 951
Indexes created Sat Sep 20 22:09:52 GMT 2025