kern_malloc.c revision 1.38
1 /* $NetBSD: kern_malloc.c,v 1.38 1998/11/04 06:19:56 chs Exp $ */ 2 3 /* 4 * Copyright (c) 1996 Christopher G. Demetriou. All rights reserved. 5 * Copyright (c) 1987, 1991, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)kern_malloc.c 8.4 (Berkeley) 5/20/95 37 */ 38 39 #include "opt_lockdebug.h" 40 #include "opt_uvm.h" 41 42 #include <sys/param.h> 43 #include <sys/proc.h> 44 #include <sys/map.h> 45 #include <sys/kernel.h> 46 #include <sys/malloc.h> 47 #include <sys/systm.h> 48 49 #include <vm/vm.h> 50 #include <vm/vm_kern.h> 51 52 #if defined(UVM) 53 #include <uvm/uvm_extern.h> 54 55 static struct vm_map kmem_map_store; 56 vm_map_t kmem_map = NULL; 57 #endif 58 59 #include "opt_kmemstats.h" 60 #include "opt_malloclog.h" 61 62 struct kmembuckets bucket[MINBUCKET + 16]; 63 struct kmemstats kmemstats[M_LAST]; 64 struct kmemusage *kmemusage; 65 char *kmembase, *kmemlimit; 66 const char *memname[] = INITKMEMNAMES; 67 68 #ifdef MALLOCLOG 69 #ifndef MALLOCLOGSIZE 70 #define MALLOCLOGSIZE 100000 71 #endif 72 73 struct malloclog { 74 void *addr; 75 long size; 76 int type; 77 int action; 78 const char *file; 79 long line; 80 } malloclog[MALLOCLOGSIZE]; 81 82 long malloclogptr; 83 84 static void domlog __P((void *a, long size, int type, int action, 85 const char *file, long line)); 86 static void hitmlog __P((void *a)); 87 88 static void 89 domlog(a, size, type, action, file, line) 90 void *a; 91 long size; 92 int type; 93 int action; 94 const char *file; 95 long line; 96 { 97 98 malloclog[malloclogptr].addr = a; 99 malloclog[malloclogptr].size = size; 100 malloclog[malloclogptr].type = type; 101 malloclog[malloclogptr].action = action; 102 malloclog[malloclogptr].file = file; 103 malloclog[malloclogptr].line = line; 104 malloclogptr++; 105 if (malloclogptr >= MALLOCLOGSIZE) 106 malloclogptr = 0; 107 } 108 109 static void 110 hitmlog(a) 111 void *a; 112 { 113 struct malloclog *lp; 114 long l; 115 116 #define PRT \ 117 if (malloclog[l].addr == a && malloclog[l].action) { \ 118 lp = &malloclog[l]; \ 119 printf("malloc log entry %ld:\n", l); \ 120 printf("\taddr = %p\n", lp->addr); \ 121 printf("\tsize = %ld\n", lp->size); \ 122 printf("\ttype = %s\n", memname[lp->type]); \ 123 printf("\taction = %s\n", lp->action == 1 ? "alloc" : "free"); \ 124 printf("\tfile = %s\n", lp->file); \ 125 printf("\tline = %ld\n", lp->line); \ 126 } 127 128 for (l = malloclogptr; l < MALLOCLOGSIZE; l++) 129 PRT 130 131 for (l = 0; l < malloclogptr; l++) 132 PRT 133 } 134 #endif /* MALLOCLOG */ 135 136 #ifdef DIAGNOSTIC 137 /* 138 * This structure provides a set of masks to catch unaligned frees. 139 */ 140 long addrmask[] = { 0, 141 0x00000001, 0x00000003, 0x00000007, 0x0000000f, 142 0x0000001f, 0x0000003f, 0x0000007f, 0x000000ff, 143 0x000001ff, 0x000003ff, 0x000007ff, 0x00000fff, 144 0x00001fff, 0x00003fff, 0x00007fff, 0x0000ffff, 145 }; 146 147 /* 148 * The WEIRD_ADDR is used as known text to copy into free objects so 149 * that modifications after frees can be detected. 150 */ 151 #define WEIRD_ADDR ((unsigned) 0xdeadbeef) 152 #define MAX_COPY 32 153 154 /* 155 * Normally the freelist structure is used only to hold the list pointer 156 * for free objects. However, when running with diagnostics, the first 157 * 8 bytes of the structure is unused except for diagnostic information, 158 * and the free list pointer is at offst 8 in the structure. Since the 159 * first 8 bytes is the portion of the structure most often modified, this 160 * helps to detect memory reuse problems and avoid free list corruption. 161 */ 162 struct freelist { 163 int32_t spare0; 164 int16_t type; 165 int16_t spare1; 166 caddr_t next; 167 }; 168 #else /* !DIAGNOSTIC */ 169 struct freelist { 170 caddr_t next; 171 }; 172 #endif /* DIAGNOSTIC */ 173 174 /* 175 * Allocate a block of memory 176 */ 177 #ifdef MALLOCLOG 178 void * 179 _malloc(size, type, flags, file, line) 180 unsigned long size; 181 int type, flags; 182 const char *file; 183 long line; 184 #else 185 void * 186 malloc(size, type, flags) 187 unsigned long size; 188 int type, flags; 189 #endif /* MALLOCLOG */ 190 { 191 register struct kmembuckets *kbp; 192 register struct kmemusage *kup; 193 register struct freelist *freep; 194 long indx, npg, allocsize; 195 int s; 196 caddr_t va, cp, savedlist; 197 #ifdef DIAGNOSTIC 198 int32_t *end, *lp; 199 int copysize; 200 const char *savedtype; 201 #endif 202 #ifdef LOCKDEBUG 203 extern int simplelockrecurse; 204 #endif 205 #ifdef KMEMSTATS 206 register struct kmemstats *ksp = &kmemstats[type]; 207 208 if (((unsigned long)type) > M_LAST) 209 panic("malloc - bogus type"); 210 #endif 211 indx = BUCKETINDX(size); 212 kbp = &bucket[indx]; 213 s = splimp(); 214 #ifdef KMEMSTATS 215 while (ksp->ks_memuse >= ksp->ks_limit) { 216 if (flags & M_NOWAIT) { 217 splx(s); 218 return ((void *) NULL); 219 } 220 if (ksp->ks_limblocks < 65535) 221 ksp->ks_limblocks++; 222 tsleep((caddr_t)ksp, PSWP+2, memname[type], 0); 223 } 224 ksp->ks_size |= 1 << indx; 225 #endif 226 #ifdef DIAGNOSTIC 227 copysize = 1 << indx < MAX_COPY ? 1 << indx : MAX_COPY; 228 #endif 229 #ifdef LOCKDEBUG 230 if (flags & M_NOWAIT) 231 simplelockrecurse++; 232 #endif 233 if (kbp->kb_next == NULL) { 234 kbp->kb_last = NULL; 235 if (size > MAXALLOCSAVE) 236 allocsize = roundup(size, CLBYTES); 237 else 238 allocsize = 1 << indx; 239 npg = clrnd(btoc(allocsize)); 240 #if defined(UVM) 241 va = (caddr_t) uvm_km_kmemalloc(kmem_map, uvmexp.kmem_object, 242 (vsize_t)ctob(npg), 243 (flags & M_NOWAIT) ? UVM_KMF_NOWAIT : 0); 244 #else 245 va = (caddr_t) kmem_malloc(kmem_map, (vsize_t)ctob(npg), 246 !(flags & M_NOWAIT)); 247 #endif 248 if (va == NULL) { 249 /* 250 * Kmem_malloc() can return NULL, even if it can 251 * wait, if there is no map space avaiable, because 252 * it can't fix that problem. Neither can we, 253 * right now. (We should release pages which 254 * are completely free and which are in buckets 255 * with too many free elements.) 256 */ 257 if ((flags & M_NOWAIT) == 0) 258 panic("malloc: out of space in kmem_map"); 259 #ifdef LOCKDEBUG 260 simplelockrecurse--; 261 #endif 262 splx(s); 263 return ((void *) NULL); 264 } 265 #ifdef KMEMSTATS 266 kbp->kb_total += kbp->kb_elmpercl; 267 #endif 268 kup = btokup(va); 269 kup->ku_indx = indx; 270 if (allocsize > MAXALLOCSAVE) { 271 if (npg > 65535) 272 panic("malloc: allocation too large"); 273 kup->ku_pagecnt = npg; 274 #ifdef KMEMSTATS 275 ksp->ks_memuse += allocsize; 276 #endif 277 goto out; 278 } 279 #ifdef KMEMSTATS 280 kup->ku_freecnt = kbp->kb_elmpercl; 281 kbp->kb_totalfree += kbp->kb_elmpercl; 282 #endif 283 /* 284 * Just in case we blocked while allocating memory, 285 * and someone else also allocated memory for this 286 * bucket, don't assume the list is still empty. 287 */ 288 savedlist = kbp->kb_next; 289 kbp->kb_next = cp = va + (npg * NBPG) - allocsize; 290 for (;;) { 291 freep = (struct freelist *)cp; 292 #ifdef DIAGNOSTIC 293 /* 294 * Copy in known text to detect modification 295 * after freeing. 296 */ 297 end = (int32_t *)&cp[copysize]; 298 for (lp = (int32_t *)cp; lp < end; lp++) 299 *lp = WEIRD_ADDR; 300 freep->type = M_FREE; 301 #endif /* DIAGNOSTIC */ 302 if (cp <= va) 303 break; 304 cp -= allocsize; 305 freep->next = cp; 306 } 307 freep->next = savedlist; 308 if (kbp->kb_last == NULL) 309 kbp->kb_last = (caddr_t)freep; 310 } 311 va = kbp->kb_next; 312 kbp->kb_next = ((struct freelist *)va)->next; 313 #ifdef DIAGNOSTIC 314 freep = (struct freelist *)va; 315 savedtype = (unsigned)freep->type < M_LAST ? 316 memname[freep->type] : "???"; 317 #if defined(UVM) 318 if (kbp->kb_next) { 319 int rv; 320 vaddr_t addr = (vaddr_t)kbp->kb_next; 321 322 vm_map_lock_read(kmem_map); 323 rv = uvm_map_checkprot(kmem_map, addr, 324 addr + sizeof(struct freelist), 325 VM_PROT_WRITE); 326 vm_map_unlock_read(kmem_map); 327 328 if (!rv) 329 #else 330 if (kbp->kb_next && 331 !kernacc(kbp->kb_next, sizeof(struct freelist), 0)) 332 #endif 333 { 334 printf( 335 "%s %ld of object %p size %ld %s %s (invalid addr %p)\n", 336 "Data modified on freelist: word", 337 (long)((int32_t *)&kbp->kb_next - (int32_t *)kbp), 338 va, size, "previous type", savedtype, kbp->kb_next); 339 #ifdef MALLOCLOG 340 hitmlog(va); 341 #endif 342 kbp->kb_next = NULL; 343 #if defined(UVM) 344 } 345 #endif 346 } 347 348 /* Fill the fields that we've used with WEIRD_ADDR */ 349 #if BYTE_ORDER == BIG_ENDIAN 350 freep->type = WEIRD_ADDR >> 16; 351 #endif 352 #if BYTE_ORDER == LITTLE_ENDIAN 353 freep->type = (short)WEIRD_ADDR; 354 #endif 355 end = (int32_t *)&freep->next + 356 (sizeof(freep->next) / sizeof(int32_t)); 357 for (lp = (int32_t *)&freep->next; lp < end; lp++) 358 *lp = WEIRD_ADDR; 359 360 /* and check that the data hasn't been modified. */ 361 end = (int32_t *)&va[copysize]; 362 for (lp = (int32_t *)va; lp < end; lp++) { 363 if (*lp == WEIRD_ADDR) 364 continue; 365 printf("%s %ld of object %p size %ld %s %s (0x%x != 0x%x)\n", 366 "Data modified on freelist: word", 367 (long)(lp - (int32_t *)va), va, size, "previous type", 368 savedtype, *lp, WEIRD_ADDR); 369 #ifdef MALLOCLOG 370 hitmlog(va); 371 #endif 372 break; 373 } 374 375 freep->spare0 = 0; 376 #endif /* DIAGNOSTIC */ 377 #ifdef KMEMSTATS 378 kup = btokup(va); 379 if (kup->ku_indx != indx) 380 panic("malloc: wrong bucket"); 381 if (kup->ku_freecnt == 0) 382 panic("malloc: lost data"); 383 kup->ku_freecnt--; 384 kbp->kb_totalfree--; 385 ksp->ks_memuse += 1 << indx; 386 out: 387 kbp->kb_calls++; 388 ksp->ks_inuse++; 389 ksp->ks_calls++; 390 if (ksp->ks_memuse > ksp->ks_maxused) 391 ksp->ks_maxused = ksp->ks_memuse; 392 #else 393 out: 394 #endif 395 #ifdef MALLOCLOG 396 domlog(va, size, type, 1, file, line); 397 #endif 398 splx(s); 399 #ifdef LOCKDEBUG 400 if (flags & M_NOWAIT) 401 simplelockrecurse--; 402 #endif 403 return ((void *) va); 404 } 405 406 /* 407 * Free a block of memory allocated by malloc. 408 */ 409 #ifdef MALLOCLOG 410 void 411 _free(addr, type, file, line) 412 void *addr; 413 int type; 414 const char *file; 415 long line; 416 #else 417 void 418 free(addr, type) 419 void *addr; 420 int type; 421 #endif /* MALLOCLOG */ 422 { 423 register struct kmembuckets *kbp; 424 register struct kmemusage *kup; 425 register struct freelist *freep; 426 long size; 427 int s; 428 #ifdef DIAGNOSTIC 429 caddr_t cp; 430 int32_t *end, *lp; 431 long alloc, copysize; 432 #endif 433 #ifdef KMEMSTATS 434 register struct kmemstats *ksp = &kmemstats[type]; 435 #endif 436 437 kup = btokup(addr); 438 size = 1 << kup->ku_indx; 439 kbp = &bucket[kup->ku_indx]; 440 s = splimp(); 441 #ifdef MALLOCLOG 442 domlog(addr, 0, type, 2, file, line); 443 #endif 444 #ifdef DIAGNOSTIC 445 /* 446 * Check for returns of data that do not point to the 447 * beginning of the allocation. 448 */ 449 if (size > NBPG * CLSIZE) 450 alloc = addrmask[BUCKETINDX(NBPG * CLSIZE)]; 451 else 452 alloc = addrmask[kup->ku_indx]; 453 if (((u_long)addr & alloc) != 0) 454 panic("free: unaligned addr %p, size %ld, type %s, mask %ld\n", 455 addr, size, memname[type], alloc); 456 #endif /* DIAGNOSTIC */ 457 if (size > MAXALLOCSAVE) { 458 #if defined(UVM) 459 uvm_km_free(kmem_map, (vaddr_t)addr, ctob(kup->ku_pagecnt)); 460 #else 461 kmem_free(kmem_map, (vaddr_t)addr, ctob(kup->ku_pagecnt)); 462 #endif 463 #ifdef KMEMSTATS 464 size = kup->ku_pagecnt << PGSHIFT; 465 ksp->ks_memuse -= size; 466 kup->ku_indx = 0; 467 kup->ku_pagecnt = 0; 468 if (ksp->ks_memuse + size >= ksp->ks_limit && 469 ksp->ks_memuse < ksp->ks_limit) 470 wakeup((caddr_t)ksp); 471 ksp->ks_inuse--; 472 kbp->kb_total -= 1; 473 #endif 474 splx(s); 475 return; 476 } 477 freep = (struct freelist *)addr; 478 #ifdef DIAGNOSTIC 479 /* 480 * Check for multiple frees. Use a quick check to see if 481 * it looks free before laboriously searching the freelist. 482 */ 483 if (freep->spare0 == WEIRD_ADDR) { 484 for (cp = kbp->kb_next; cp; 485 cp = ((struct freelist *)cp)->next) { 486 if (addr != cp) 487 continue; 488 printf("multiply freed item %p\n", addr); 489 #ifdef MALLOCLOG 490 hitmlog(addr); 491 #endif 492 panic("free: duplicated free"); 493 } 494 } 495 #ifdef LOCKDEBUG 496 /* 497 * Check if we're freeing a locked simple lock. 498 */ 499 simple_lock_freecheck(addr, addr + size); 500 #endif 501 /* 502 * Copy in known text to detect modification after freeing 503 * and to make it look free. Also, save the type being freed 504 * so we can list likely culprit if modification is detected 505 * when the object is reallocated. 506 */ 507 copysize = size < MAX_COPY ? size : MAX_COPY; 508 end = (int32_t *)&((caddr_t)addr)[copysize]; 509 for (lp = (int32_t *)addr; lp < end; lp++) 510 *lp = WEIRD_ADDR; 511 freep->type = type; 512 #endif /* DIAGNOSTIC */ 513 #ifdef KMEMSTATS 514 kup->ku_freecnt++; 515 if (kup->ku_freecnt >= kbp->kb_elmpercl) { 516 if (kup->ku_freecnt > kbp->kb_elmpercl) 517 panic("free: multiple frees"); 518 else if (kbp->kb_totalfree > kbp->kb_highwat) 519 kbp->kb_couldfree++; 520 } 521 kbp->kb_totalfree++; 522 ksp->ks_memuse -= size; 523 if (ksp->ks_memuse + size >= ksp->ks_limit && 524 ksp->ks_memuse < ksp->ks_limit) 525 wakeup((caddr_t)ksp); 526 ksp->ks_inuse--; 527 #endif 528 if (kbp->kb_next == NULL) 529 kbp->kb_next = addr; 530 else 531 ((struct freelist *)kbp->kb_last)->next = addr; 532 freep->next = NULL; 533 kbp->kb_last = addr; 534 splx(s); 535 } 536 537 /* 538 * Change the size of a block of memory. 539 */ 540 void * 541 realloc(curaddr, newsize, type, flags) 542 void *curaddr; 543 unsigned long newsize; 544 int type, flags; 545 { 546 register struct kmemusage *kup; 547 long cursize; 548 void *newaddr; 549 #ifdef DIAGNOSTIC 550 long alloc; 551 #endif 552 553 /* 554 * Realloc() with a NULL pointer is the same as malloc(). 555 */ 556 if (curaddr == NULL) 557 return (malloc(newsize, type, flags)); 558 559 /* 560 * Realloc() with zero size is the same as free(). 561 */ 562 if (newsize == 0) { 563 free(curaddr, type); 564 return (NULL); 565 } 566 567 /* 568 * Find out how large the old allocation was (and do some 569 * sanity checking). 570 */ 571 kup = btokup(curaddr); 572 cursize = 1 << kup->ku_indx; 573 574 #ifdef DIAGNOSTIC 575 /* 576 * Check for returns of data that do not point to the 577 * beginning of the allocation. 578 */ 579 if (cursize > NBPG * CLSIZE) 580 alloc = addrmask[BUCKETINDX(NBPG * CLSIZE)]; 581 else 582 alloc = addrmask[kup->ku_indx]; 583 if (((u_long)curaddr & alloc) != 0) 584 panic("realloc: unaligned addr %p, size %ld, type %s, mask %ld\n", 585 curaddr, cursize, memname[type], alloc); 586 #endif /* DIAGNOSTIC */ 587 588 if (cursize > MAXALLOCSAVE) 589 cursize = ctob(kup->ku_pagecnt); 590 591 /* 592 * If we already actually have as much as they want, we're done. 593 */ 594 if (newsize <= cursize) 595 return (curaddr); 596 597 /* 598 * Can't satisfy the allocation with the existing block. 599 * Allocate a new one and copy the data. 600 */ 601 newaddr = malloc(newsize, type, flags); 602 if (newaddr == NULL) { 603 /* 604 * Malloc() failed, because flags included M_NOWAIT. 605 * Return NULL to indicate that failure. The old 606 * pointer is still valid. 607 */ 608 return NULL; 609 } 610 memcpy(newaddr, curaddr, cursize); 611 612 /* 613 * We were successful: free the old allocation and return 614 * the new one. 615 */ 616 free(curaddr, type); 617 return (newaddr); 618 } 619 620 /* 621 * Initialize the kernel memory allocator 622 */ 623 void 624 kmeminit() 625 { 626 #ifdef KMEMSTATS 627 register long indx; 628 #endif 629 int npg; 630 631 #if ((MAXALLOCSAVE & (MAXALLOCSAVE - 1)) != 0) 632 ERROR!_kmeminit:_MAXALLOCSAVE_not_power_of_2 633 #endif 634 #if (MAXALLOCSAVE > MINALLOCSIZE * 32768) 635 ERROR!_kmeminit:_MAXALLOCSAVE_too_big 636 #endif 637 #if (MAXALLOCSAVE < CLBYTES) 638 ERROR!_kmeminit:_MAXALLOCSAVE_too_small 639 #endif 640 641 if (sizeof(struct freelist) > (1 << MINBUCKET)) 642 panic("minbucket too small/struct freelist too big"); 643 644 npg = VM_KMEM_SIZE/ NBPG; 645 #if defined(UVM) 646 kmemusage = (struct kmemusage *) uvm_km_zalloc(kernel_map, 647 (vsize_t)(npg * sizeof(struct kmemusage))); 648 kmem_map = uvm_km_suballoc(kernel_map, (vaddr_t *)&kmembase, 649 (vaddr_t *)&kmemlimit, (vsize_t)(npg * NBPG), 650 FALSE, FALSE, &kmem_map_store); 651 #else 652 kmemusage = (struct kmemusage *) kmem_alloc(kernel_map, 653 (vsize_t)(npg * sizeof(struct kmemusage))); 654 kmem_map = kmem_suballoc(kernel_map, (vaddr_t *)&kmembase, 655 (vaddr_t *)&kmemlimit, (vsize_t)(npg * NBPG), FALSE); 656 #endif 657 #ifdef KMEMSTATS 658 for (indx = 0; indx < MINBUCKET + 16; indx++) { 659 if (1 << indx >= CLBYTES) 660 bucket[indx].kb_elmpercl = 1; 661 else 662 bucket[indx].kb_elmpercl = CLBYTES / (1 << indx); 663 bucket[indx].kb_highwat = 5 * bucket[indx].kb_elmpercl; 664 } 665 for (indx = 0; indx < M_LAST; indx++) 666 kmemstats[indx].ks_limit = npg * NBPG * 6 / 10; 667 #endif 668 } 669
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