kern_malloc.c revision 1.88
1 /* $NetBSD: kern_malloc.c,v 1.88 2003/09/27 23:10:47 mycroft 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 1.88 2003/09/27 23:10:47 mycroft 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 const char *savedtype; 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 avaiable, 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 savedtype = freep->type->ks_shortdesc; 381 if (kbp->kb_next) { 382 int rv; 383 vaddr_t addr = (vaddr_t)kbp->kb_next; 384 385 vm_map_lock(kmem_map); 386 rv = uvm_map_checkprot(kmem_map, addr, 387 addr + sizeof(struct freelist), VM_PROT_WRITE); 388 vm_map_unlock(kmem_map); 389 390 if (__predict_false(rv == 0)) { 391 printf("Data modified on freelist: " 392 "word %ld of object %p size %ld previous type %s " 393 "(invalid addr %p)\n", 394 (long)((int32_t *)&kbp->kb_next - (int32_t *)kbp), 395 va, size, "foo", kbp->kb_next); 396 #ifdef MALLOCLOG 397 hitmlog(va); 398 #endif 399 kbp->kb_next = NULL; 400 } 401 } 402 403 /* Fill the fields that we've used with WEIRD_ADDR */ 404 #ifdef _LP64 405 freep->type = (struct malloc_type *) 406 (WEIRD_ADDR | (((u_long) WEIRD_ADDR) << 32)); 407 #else 408 freep->type = (struct malloc_type *) WEIRD_ADDR; 409 #endif 410 end = (uint32_t *)&freep->next + 411 (sizeof(freep->next) / sizeof(int32_t)); 412 for (lp = (uint32_t *)&freep->next; lp < end; lp++) 413 *lp = WEIRD_ADDR; 414 415 /* and check that the data hasn't been modified. */ 416 end = (uint32_t *)&va[copysize]; 417 for (lp = (uint32_t *)va; lp < end; lp++) { 418 if (__predict_true(*lp == WEIRD_ADDR)) 419 continue; 420 printf("Data modified on freelist: " 421 "word %ld of object %p size %ld previous type %s " 422 "(0x%x != 0x%x)\n", 423 (long)(lp - (uint32_t *)va), va, size, 424 "bar", *lp, WEIRD_ADDR); 425 #ifdef MALLOCLOG 426 hitmlog(va); 427 #endif 428 break; 429 } 430 431 freep->spare0 = 0; 432 #endif /* DIAGNOSTIC */ 433 #ifdef KMEMSTATS 434 kup = btokup(va); 435 if (kup->ku_indx != indx) 436 panic("malloc: wrong bucket"); 437 if (kup->ku_freecnt == 0) 438 panic("malloc: lost data"); 439 kup->ku_freecnt--; 440 kbp->kb_totalfree--; 441 ksp->ks_memuse += 1 << indx; 442 out: 443 kbp->kb_calls++; 444 ksp->ks_inuse++; 445 ksp->ks_calls++; 446 if (ksp->ks_memuse > ksp->ks_maxused) 447 ksp->ks_maxused = ksp->ks_memuse; 448 #else 449 out: 450 #endif 451 #ifdef MALLOCLOG 452 domlog(va, size, ksp, 1, file, line); 453 #endif 454 simple_unlock(&malloc_slock); 455 splx(s); 456 if ((flags & M_ZERO) != 0) 457 memset(va, 0, size); 458 return ((void *) va); 459 } 460 461 /* 462 * Free a block of memory allocated by malloc. 463 */ 464 #ifdef MALLOCLOG 465 void 466 _free(void *addr, struct malloc_type *ksp, const char *file, long line) 467 #else 468 void 469 free(void *addr, struct malloc_type *ksp) 470 #endif /* MALLOCLOG */ 471 { 472 struct kmembuckets *kbp; 473 struct kmemusage *kup; 474 struct freelist *freep; 475 long size; 476 int s; 477 #ifdef DIAGNOSTIC 478 caddr_t cp; 479 int32_t *end, *lp; 480 long alloc, copysize; 481 #endif 482 483 #ifdef MALLOC_DEBUG 484 if (debug_free(addr, ksp)) 485 return; 486 #endif 487 488 #ifdef DIAGNOSTIC 489 /* 490 * Ensure that we're free'ing something that we could 491 * have allocated in the first place. That is, check 492 * to see that the address is within kmem_map. 493 */ 494 if (__predict_false((vaddr_t)addr < vm_map_min(kmem_map) || 495 (vaddr_t)addr >= vm_map_max(kmem_map))) 496 panic("free: addr %p not within kmem_map", addr); 497 #endif 498 499 kup = btokup(addr); 500 size = 1 << kup->ku_indx; 501 kbp = &bucket[kup->ku_indx]; 502 s = splvm(); 503 simple_lock(&malloc_slock); 504 #ifdef MALLOCLOG 505 domlog(addr, 0, ksp, 2, file, line); 506 #endif 507 #ifdef DIAGNOSTIC 508 /* 509 * Check for returns of data that do not point to the 510 * beginning of the allocation. 511 */ 512 if (size > PAGE_SIZE) 513 alloc = addrmask[BUCKETINDX(PAGE_SIZE)]; 514 else 515 alloc = addrmask[kup->ku_indx]; 516 if (((u_long)addr & alloc) != 0) 517 panic("free: unaligned addr %p, size %ld, type %s, mask %ld", 518 addr, size, ksp->ks_shortdesc, alloc); 519 #endif /* DIAGNOSTIC */ 520 if (size > MAXALLOCSAVE) { 521 uvm_km_free(kmem_map, (vaddr_t)addr, ctob(kup->ku_pagecnt)); 522 #ifdef KMEMSTATS 523 size = kup->ku_pagecnt << PGSHIFT; 524 ksp->ks_memuse -= size; 525 kup->ku_indx = 0; 526 kup->ku_pagecnt = 0; 527 if (ksp->ks_memuse + size >= ksp->ks_limit && 528 ksp->ks_memuse < ksp->ks_limit) 529 wakeup((caddr_t)ksp); 530 #ifdef DIAGNOSTIC 531 if (ksp->ks_inuse == 0) 532 panic("free 1: inuse 0, probable double free"); 533 #endif 534 ksp->ks_inuse--; 535 kbp->kb_total -= 1; 536 #endif 537 simple_unlock(&malloc_slock); 538 splx(s); 539 return; 540 } 541 freep = (struct freelist *)addr; 542 #ifdef DIAGNOSTIC 543 /* 544 * Check for multiple frees. Use a quick check to see if 545 * it looks free before laboriously searching the freelist. 546 */ 547 if (__predict_false(freep->spare0 == WEIRD_ADDR)) { 548 for (cp = kbp->kb_next; cp; 549 cp = ((struct freelist *)cp)->next) { 550 if (addr != cp) 551 continue; 552 printf("multiply freed item %p\n", addr); 553 #ifdef MALLOCLOG 554 hitmlog(addr); 555 #endif 556 panic("free: duplicated free"); 557 } 558 } 559 #ifdef LOCKDEBUG 560 /* 561 * Check if we're freeing a locked simple lock. 562 */ 563 simple_lock_freecheck(addr, (char *)addr + size); 564 #endif 565 /* 566 * Copy in known text to detect modification after freeing 567 * and to make it look free. Also, save the type being freed 568 * so we can list likely culprit if modification is detected 569 * when the object is reallocated. 570 */ 571 copysize = size < MAX_COPY ? size : MAX_COPY; 572 end = (int32_t *)&((caddr_t)addr)[copysize]; 573 for (lp = (int32_t *)addr; lp < end; lp++) 574 *lp = WEIRD_ADDR; 575 freep->type = ksp; 576 #endif /* DIAGNOSTIC */ 577 #ifdef KMEMSTATS 578 kup->ku_freecnt++; 579 if (kup->ku_freecnt >= kbp->kb_elmpercl) { 580 if (kup->ku_freecnt > kbp->kb_elmpercl) 581 panic("free: multiple frees"); 582 else if (kbp->kb_totalfree > kbp->kb_highwat) 583 kbp->kb_couldfree++; 584 } 585 kbp->kb_totalfree++; 586 ksp->ks_memuse -= size; 587 if (ksp->ks_memuse + size >= ksp->ks_limit && 588 ksp->ks_memuse < ksp->ks_limit) 589 wakeup((caddr_t)ksp); 590 #ifdef DIAGNOSTIC 591 if (ksp->ks_inuse == 0) 592 panic("free 2: inuse 0, probable double free"); 593 #endif 594 ksp->ks_inuse--; 595 #endif 596 if (kbp->kb_next == NULL) 597 kbp->kb_next = addr; 598 else 599 ((struct freelist *)kbp->kb_last)->next = addr; 600 freep->next = NULL; 601 kbp->kb_last = addr; 602 simple_unlock(&malloc_slock); 603 splx(s); 604 } 605 606 /* 607 * Change the size of a block of memory. 608 */ 609 void * 610 realloc(void *curaddr, unsigned long newsize, struct malloc_type *ksp, 611 int flags) 612 { 613 struct kmemusage *kup; 614 unsigned long cursize; 615 void *newaddr; 616 #ifdef DIAGNOSTIC 617 long alloc; 618 #endif 619 620 /* 621 * realloc() with a NULL pointer is the same as malloc(). 622 */ 623 if (curaddr == NULL) 624 return (malloc(newsize, ksp, flags)); 625 626 /* 627 * realloc() with zero size is the same as free(). 628 */ 629 if (newsize == 0) { 630 free(curaddr, ksp); 631 return (NULL); 632 } 633 634 #ifdef LOCKDEBUG 635 if ((flags & M_NOWAIT) == 0) 636 simple_lock_only_held(NULL, "realloc"); 637 #endif 638 639 /* 640 * Find out how large the old allocation was (and do some 641 * sanity checking). 642 */ 643 kup = btokup(curaddr); 644 cursize = 1 << kup->ku_indx; 645 646 #ifdef DIAGNOSTIC 647 /* 648 * Check for returns of data that do not point to the 649 * beginning of the allocation. 650 */ 651 if (cursize > PAGE_SIZE) 652 alloc = addrmask[BUCKETINDX(PAGE_SIZE)]; 653 else 654 alloc = addrmask[kup->ku_indx]; 655 if (((u_long)curaddr & alloc) != 0) 656 panic("realloc: " 657 "unaligned addr %p, size %ld, type %s, mask %ld\n", 658 curaddr, cursize, ksp->ks_shortdesc, alloc); 659 #endif /* DIAGNOSTIC */ 660 661 if (cursize > MAXALLOCSAVE) 662 cursize = ctob(kup->ku_pagecnt); 663 664 /* 665 * If we already actually have as much as they want, we're done. 666 */ 667 if (newsize <= cursize) 668 return (curaddr); 669 670 /* 671 * Can't satisfy the allocation with the existing block. 672 * Allocate a new one and copy the data. 673 */ 674 newaddr = malloc(newsize, ksp, flags); 675 if (__predict_false(newaddr == NULL)) { 676 /* 677 * malloc() failed, because flags included M_NOWAIT. 678 * Return NULL to indicate that failure. The old 679 * pointer is still valid. 680 */ 681 return (NULL); 682 } 683 memcpy(newaddr, curaddr, cursize); 684 685 /* 686 * We were successful: free the old allocation and return 687 * the new one. 688 */ 689 free(curaddr, ksp); 690 return (newaddr); 691 } 692 693 /* 694 * Roundup size to the actual allocation size. 695 */ 696 unsigned long 697 malloc_roundup(unsigned long size) 698 { 699 700 if (size > MAXALLOCSAVE) 701 return (roundup(size, PAGE_SIZE)); 702 else 703 return (1 << BUCKETINDX(size)); 704 } 705 706 /* 707 * Add a malloc type to the system. 708 */ 709 void 710 malloc_type_attach(struct malloc_type *type) 711 { 712 713 if (nkmempages == 0) 714 panic("malloc_type_attach: nkmempages == 0"); 715 716 if (type->ks_magic != M_MAGIC) 717 panic("malloc_type_attach: bad magic"); 718 719 #ifdef DIAGNOSTIC 720 { 721 struct malloc_type *ksp; 722 for (ksp = kmemstatistics; ksp != NULL; ksp = ksp->ks_next) { 723 if (ksp == type) 724 panic("malloc_type_attach: already on list"); 725 } 726 } 727 #endif 728 729 #ifdef KMEMSTATS 730 if (type->ks_limit == 0) 731 type->ks_limit = ((u_long)nkmempages << PAGE_SHIFT) * 6U / 10U; 732 #else 733 type->ks_limit = 0; 734 #endif 735 736 type->ks_next = kmemstatistics; 737 kmemstatistics = type; 738 } 739 740 /* 741 * Remove a malloc type from the system.. 742 */ 743 void 744 malloc_type_detach(struct malloc_type *type) 745 { 746 struct malloc_type *ksp; 747 748 #ifdef DIAGNOSTIC 749 if (type->ks_magic != M_MAGIC) 750 panic("malloc_type_detach: bad magic"); 751 #endif 752 753 if (type == kmemstatistics) 754 kmemstatistics = type->ks_next; 755 else { 756 for (ksp = kmemstatistics; ksp->ks_next != NULL; 757 ksp = ksp->ks_next) { 758 if (ksp->ks_next == type) { 759 ksp->ks_next = type->ks_next; 760 break; 761 } 762 } 763 #ifdef DIAGNOSTIC 764 if (ksp->ks_next == NULL) 765 panic("malloc_type_detach: not on list"); 766 #endif 767 } 768 type->ks_next = NULL; 769 } 770 771 /* 772 * Set the limit on a malloc type. 773 */ 774 void 775 malloc_type_setlimit(struct malloc_type *type, u_long limit) 776 { 777 #ifdef KMEMSTATS 778 int s; 779 780 s = splvm(); 781 type->ks_limit = limit; 782 splx(s); 783 #endif 784 } 785 786 /* 787 * Compute the number of pages that kmem_map will map, that is, 788 * the size of the kernel malloc arena. 789 */ 790 void 791 kmeminit_nkmempages(void) 792 { 793 int npages; 794 795 if (nkmempages != 0) { 796 /* 797 * It's already been set (by us being here before, or 798 * by patching or kernel config options), bail out now. 799 */ 800 return; 801 } 802 803 /* 804 * We use the following (simple) formula: 805 * 806 * - Starting point is physical memory / 4. 807 * 808 * - Clamp it down to NKMEMPAGES_MAX. 809 * 810 * - Round it up to NKMEMPAGES_MIN. 811 */ 812 npages = physmem / 4; 813 814 if (npages > NKMEMPAGES_MAX) 815 npages = NKMEMPAGES_MAX; 816 817 if (npages < NKMEMPAGES_MIN) 818 npages = NKMEMPAGES_MIN; 819 820 nkmempages = npages; 821 } 822 823 /* 824 * Initialize the kernel memory allocator 825 */ 826 void 827 kmeminit(void) 828 { 829 __link_set_decl(malloc_types, struct malloc_type); 830 struct malloc_type * const *ksp; 831 vaddr_t kmb, kml; 832 #ifdef KMEMSTATS 833 long indx; 834 #endif 835 836 #if ((MAXALLOCSAVE & (MAXALLOCSAVE - 1)) != 0) 837 ERROR!_kmeminit:_MAXALLOCSAVE_not_power_of_2 838 #endif 839 #if (MAXALLOCSAVE > MINALLOCSIZE * 32768) 840 ERROR!_kmeminit:_MAXALLOCSAVE_too_big 841 #endif 842 #if (MAXALLOCSAVE < NBPG) 843 ERROR!_kmeminit:_MAXALLOCSAVE_too_small 844 #endif 845 846 if (sizeof(struct freelist) > (1 << MINBUCKET)) 847 panic("minbucket too small/struct freelist too big"); 848 849 /* 850 * Compute the number of kmem_map pages, if we have not 851 * done so already. 852 */ 853 kmeminit_nkmempages(); 854 855 kmemusage = (struct kmemusage *) uvm_km_zalloc(kernel_map, 856 (vsize_t)(nkmempages * sizeof(struct kmemusage))); 857 kmb = 0; 858 kmem_map = uvm_km_suballoc(kernel_map, &kmb, 859 &kml, (vsize_t)(nkmempages << PAGE_SHIFT), 860 VM_MAP_INTRSAFE, FALSE, &kmem_map_store); 861 kmembase = (char *)kmb; 862 kmemlimit = (char *)kml; 863 #ifdef KMEMSTATS 864 for (indx = 0; indx < MINBUCKET + 16; indx++) { 865 if (1 << indx >= PAGE_SIZE) 866 bucket[indx].kb_elmpercl = 1; 867 else 868 bucket[indx].kb_elmpercl = PAGE_SIZE / (1 << indx); 869 bucket[indx].kb_highwat = 5 * bucket[indx].kb_elmpercl; 870 } 871 #endif 872 873 /* Attach all of the statically-linked malloc types. */ 874 __link_set_foreach(ksp, malloc_types) 875 malloc_type_attach(*ksp); 876 877 #ifdef MALLOC_DEBUG 878 debug_malloc_init(); 879 #endif 880 } 881 882 #ifdef DDB 883 #include <ddb/db_output.h> 884 885 /* 886 * Dump kmem statistics from ddb. 887 * 888 * usage: call dump_kmemstats 889 */ 890 void dump_kmemstats(void); 891 892 void 893 dump_kmemstats(void) 894 { 895 #ifdef KMEMSTATS 896 struct malloc_type *ksp; 897 898 for (ksp = kmemstatistics; ksp != NULL; ksp = ksp->ks_next) { 899 if (ksp->ks_memuse == 0) 900 continue; 901 db_printf("%s%.*s %ld\n", ksp->ks_shortdesc, 902 (int)(20 - strlen(ksp->ks_shortdesc)), 903 " ", 904 ksp->ks_memuse); 905 } 906 #else 907 db_printf("Kmem stats are not being collected.\n"); 908 #endif /* KMEMSTATS */ 909 } 910 #endif /* DDB */ 911 912 913 #if 0 914 /* 915 * Diagnostic messages about "Data modified on 916 * freelist" indicate a memory corruption, but 917 * they do not help tracking it down. 918 * This function can be called at various places 919 * to sanity check malloc's freelist and discover 920 * where does the corruption take place. 921 */ 922 int 923 freelist_sanitycheck(void) { 924 int i,j; 925 struct kmembuckets *kbp; 926 struct freelist *freep; 927 int rv = 0; 928 929 for (i = MINBUCKET; i <= MINBUCKET + 15; i++) { 930 kbp = &bucket[i]; 931 freep = (struct freelist *)kbp->kb_next; 932 j = 0; 933 while(freep) { 934 vm_map_lock(kmem_map); 935 rv = uvm_map_checkprot(kmem_map, (vaddr_t)freep, 936 (vaddr_t)freep + sizeof(struct freelist), 937 VM_PROT_WRITE); 938 vm_map_unlock(kmem_map); 939 940 if ((rv == 0) || (*(int *)freep != WEIRD_ADDR)) { 941 printf("bucket %i, chunck %d at %p modified\n", 942 i, j, freep); 943 return 1; 944 } 945 freep = (struct freelist *)freep->next; 946 j++; 947 } 948 } 949 950 return 0; 951 } 952 #endif 953
Indexes created Mon Sep 22 10:09:38 GMT 2025