kern_malloc.c revision 1.119.4.3
1 /* $NetBSD: kern_malloc.c,v 1.119.4.3 2010/03/11 15:04:17 yamt 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 1.119.4.3 2010/03/11 15:04:17 yamt Exp $"); 70 71 #include <sys/param.h> 72 #include <sys/proc.h> 73 #include <sys/kernel.h> 74 #include <sys/malloc.h> 75 #include <sys/systm.h> 76 #include <sys/debug.h> 77 #include <sys/mutex.h> 78 #include <sys/lockdebug.h> 79 80 #include <uvm/uvm_extern.h> 81 82 static struct vm_map_kernel kmem_map_store; 83 struct vm_map *kmem_map = NULL; 84 85 #include "opt_kmempages.h" 86 87 #ifdef NKMEMCLUSTERS 88 #error NKMEMCLUSTERS is obsolete; remove it from your kernel config file and use NKMEMPAGES instead or let the kernel auto-size 89 #endif 90 91 /* 92 * Default number of pages in kmem_map. We attempt to calculate this 93 * at run-time, but allow it to be either patched or set in the kernel 94 * config file. 95 */ 96 #ifndef NKMEMPAGES 97 #define NKMEMPAGES 0 98 #endif 99 int nkmempages = NKMEMPAGES; 100 101 /* 102 * Defaults for lower- and upper-bounds for the kmem_map page count. 103 * Can be overridden by kernel config options. 104 */ 105 #ifndef NKMEMPAGES_MIN 106 #define NKMEMPAGES_MIN NKMEMPAGES_MIN_DEFAULT 107 #endif 108 109 #ifndef NKMEMPAGES_MAX 110 #define NKMEMPAGES_MAX NKMEMPAGES_MAX_DEFAULT 111 #endif 112 113 #include "opt_kmemstats.h" 114 #include "opt_malloclog.h" 115 #include "opt_malloc_debug.h" 116 117 #define MINALLOCSIZE (1 << MINBUCKET) 118 #define BUCKETINDX(size) \ 119 ((size) <= (MINALLOCSIZE * 128) \ 120 ? (size) <= (MINALLOCSIZE * 8) \ 121 ? (size) <= (MINALLOCSIZE * 2) \ 122 ? (size) <= (MINALLOCSIZE * 1) \ 123 ? (MINBUCKET + 0) \ 124 : (MINBUCKET + 1) \ 125 : (size) <= (MINALLOCSIZE * 4) \ 126 ? (MINBUCKET + 2) \ 127 : (MINBUCKET + 3) \ 128 : (size) <= (MINALLOCSIZE* 32) \ 129 ? (size) <= (MINALLOCSIZE * 16) \ 130 ? (MINBUCKET + 4) \ 131 : (MINBUCKET + 5) \ 132 : (size) <= (MINALLOCSIZE * 64) \ 133 ? (MINBUCKET + 6) \ 134 : (MINBUCKET + 7) \ 135 : (size) <= (MINALLOCSIZE * 2048) \ 136 ? (size) <= (MINALLOCSIZE * 512) \ 137 ? (size) <= (MINALLOCSIZE * 256) \ 138 ? (MINBUCKET + 8) \ 139 : (MINBUCKET + 9) \ 140 : (size) <= (MINALLOCSIZE * 1024) \ 141 ? (MINBUCKET + 10) \ 142 : (MINBUCKET + 11) \ 143 : (size) <= (MINALLOCSIZE * 8192) \ 144 ? (size) <= (MINALLOCSIZE * 4096) \ 145 ? (MINBUCKET + 12) \ 146 : (MINBUCKET + 13) \ 147 : (size) <= (MINALLOCSIZE * 16384) \ 148 ? (MINBUCKET + 14) \ 149 : (MINBUCKET + 15)) 150 151 /* 152 * Array of descriptors that describe the contents of each page 153 */ 154 struct kmemusage { 155 short ku_indx; /* bucket index */ 156 union { 157 u_short freecnt;/* for small allocations, free pieces in page */ 158 u_short pagecnt;/* for large allocations, pages alloced */ 159 } ku_un; 160 }; 161 #define ku_freecnt ku_un.freecnt 162 #define ku_pagecnt ku_un.pagecnt 163 164 struct kmembuckets kmembuckets[MINBUCKET + 16]; 165 struct kmemusage *kmemusage; 166 char *kmembase, *kmemlimit; 167 168 #ifdef DEBUG 169 static void *malloc_freecheck; 170 #endif 171 172 /* 173 * Turn virtual addresses into kmem map indicies 174 */ 175 #define btokup(addr) (&kmemusage[((char *)(addr) - kmembase) >> PGSHIFT]) 176 177 struct malloc_type *kmemstatistics; 178 179 #ifdef MALLOCLOG 180 #ifndef MALLOCLOGSIZE 181 #define MALLOCLOGSIZE 100000 182 #endif 183 184 struct malloclog { 185 void *addr; 186 long size; 187 struct malloc_type *type; 188 int action; 189 const char *file; 190 long line; 191 } malloclog[MALLOCLOGSIZE]; 192 193 long malloclogptr; 194 195 /* 196 * Fuzz factor for neighbour address match this must be a mask of the lower 197 * bits we wish to ignore when comparing addresses 198 */ 199 __uintptr_t malloclog_fuzz = 0x7FL; 200 201 202 static void 203 domlog(void *a, long size, struct malloc_type *type, int action, 204 const char *file, long line) 205 { 206 207 malloclog[malloclogptr].addr = a; 208 malloclog[malloclogptr].size = size; 209 malloclog[malloclogptr].type = type; 210 malloclog[malloclogptr].action = action; 211 malloclog[malloclogptr].file = file; 212 malloclog[malloclogptr].line = line; 213 malloclogptr++; 214 if (malloclogptr >= MALLOCLOGSIZE) 215 malloclogptr = 0; 216 } 217 218 #ifdef DIAGNOSTIC 219 static void 220 hitmlog(void *a) 221 { 222 struct malloclog *lp; 223 long l; 224 225 #define PRT do { \ 226 lp = &malloclog[l]; \ 227 if (lp->addr == a && lp->action) { \ 228 printf("malloc log entry %ld:\n", l); \ 229 printf("\taddr = %p\n", lp->addr); \ 230 printf("\tsize = %ld\n", lp->size); \ 231 printf("\ttype = %s\n", lp->type->ks_shortdesc); \ 232 printf("\taction = %s\n", lp->action == 1 ? "alloc" : "free"); \ 233 printf("\tfile = %s\n", lp->file); \ 234 printf("\tline = %ld\n", lp->line); \ 235 } \ 236 } while (/* CONSTCOND */0) 237 238 /* 239 * Print fuzzy matched "neighbour" - look for the memory block that has 240 * been allocated below the address we are interested in. We look for a 241 * base address + size that is within malloclog_fuzz of our target 242 * address. If the base address and target address are the same then it is 243 * likely we have found a free (size is 0 in this case) so we won't report 244 * those, they will get reported by PRT anyway. 245 */ 246 #define NPRT do { \ 247 __uintptr_t fuzz_mask = ~(malloclog_fuzz); \ 248 lp = &malloclog[l]; \ 249 if ((__uintptr_t)lp->addr != (__uintptr_t)a && \ 250 (((__uintptr_t)lp->addr + lp->size + malloclog_fuzz) & fuzz_mask) \ 251 == ((__uintptr_t)a & fuzz_mask) && lp->action) { \ 252 printf("neighbour malloc log entry %ld:\n", l); \ 253 printf("\taddr = %p\n", lp->addr); \ 254 printf("\tsize = %ld\n", lp->size); \ 255 printf("\ttype = %s\n", lp->type->ks_shortdesc); \ 256 printf("\taction = %s\n", lp->action == 1 ? "alloc" : "free"); \ 257 printf("\tfile = %s\n", lp->file); \ 258 printf("\tline = %ld\n", lp->line); \ 259 } \ 260 } while (/* CONSTCOND */0) 261 262 for (l = malloclogptr; l < MALLOCLOGSIZE; l++) { 263 PRT; 264 NPRT; 265 } 266 267 268 for (l = 0; l < malloclogptr; l++) { 269 PRT; 270 NPRT; 271 } 272 273 #undef PRT 274 } 275 #endif /* DIAGNOSTIC */ 276 #endif /* MALLOCLOG */ 277 278 #ifdef DIAGNOSTIC 279 /* 280 * This structure provides a set of masks to catch unaligned frees. 281 */ 282 const long addrmask[] = { 0, 283 0x00000001, 0x00000003, 0x00000007, 0x0000000f, 284 0x0000001f, 0x0000003f, 0x0000007f, 0x000000ff, 285 0x000001ff, 0x000003ff, 0x000007ff, 0x00000fff, 286 0x00001fff, 0x00003fff, 0x00007fff, 0x0000ffff, 287 }; 288 289 /* 290 * The WEIRD_ADDR is used as known text to copy into free objects so 291 * that modifications after frees can be detected. 292 */ 293 #define WEIRD_ADDR ((uint32_t) 0xdeadbeef) 294 #ifdef DEBUG 295 #define MAX_COPY PAGE_SIZE 296 #else 297 #define MAX_COPY 32 298 #endif 299 300 /* 301 * Normally the freelist structure is used only to hold the list pointer 302 * for free objects. However, when running with diagnostics, the first 303 * 8/16 bytes of the structure is unused except for diagnostic information, 304 * and the free list pointer is at offset 8/16 in the structure. Since the 305 * first 8 bytes is the portion of the structure most often modified, this 306 * helps to detect memory reuse problems and avoid free list corruption. 307 */ 308 struct freelist { 309 uint32_t spare0; 310 #ifdef _LP64 311 uint32_t spare1; /* explicit padding */ 312 #endif 313 struct malloc_type *type; 314 void * next; 315 }; 316 #else /* !DIAGNOSTIC */ 317 struct freelist { 318 void * next; 319 }; 320 #endif /* DIAGNOSTIC */ 321 322 kmutex_t malloc_lock; 323 324 /* 325 * Allocate a block of memory 326 */ 327 #ifdef MALLOCLOG 328 void * 329 _kern_malloc(unsigned long size, struct malloc_type *ksp, int flags, 330 const char *file, long line) 331 #else 332 void * 333 kern_malloc(unsigned long size, struct malloc_type *ksp, int flags) 334 #endif /* MALLOCLOG */ 335 { 336 struct kmembuckets *kbp; 337 struct kmemusage *kup; 338 struct freelist *freep; 339 long indx, npg, allocsize; 340 char *va, *cp, *savedlist; 341 #ifdef DIAGNOSTIC 342 uint32_t *end, *lp; 343 int copysize; 344 #endif 345 346 #ifdef LOCKDEBUG 347 if ((flags & M_NOWAIT) == 0) { 348 ASSERT_SLEEPABLE(); 349 } 350 #endif 351 #ifdef MALLOC_DEBUG 352 if (debug_malloc(size, ksp, flags, (void *) &va)) { 353 if (va != 0) { 354 FREECHECK_OUT(&malloc_freecheck, (void *)va); 355 } 356 return ((void *) va); 357 } 358 #endif 359 indx = BUCKETINDX(size); 360 kbp = &kmembuckets[indx]; 361 mutex_spin_enter(&malloc_lock); 362 #ifdef KMEMSTATS 363 while (ksp->ks_memuse >= ksp->ks_limit) { 364 if (flags & M_NOWAIT) { 365 mutex_spin_exit(&malloc_lock); 366 return ((void *) NULL); 367 } 368 if (ksp->ks_limblocks < 65535) 369 ksp->ks_limblocks++; 370 mtsleep((void *)ksp, PSWP+2, ksp->ks_shortdesc, 0, 371 &malloc_lock); 372 } 373 ksp->ks_size |= 1 << indx; 374 #endif 375 #ifdef DIAGNOSTIC 376 copysize = 1 << indx < MAX_COPY ? 1 << indx : MAX_COPY; 377 #endif 378 if (kbp->kb_next == NULL) { 379 int s; 380 kbp->kb_last = NULL; 381 if (size > MAXALLOCSAVE) 382 allocsize = round_page(size); 383 else 384 allocsize = 1 << indx; 385 npg = btoc(allocsize); 386 mutex_spin_exit(&malloc_lock); 387 s = splvm(); 388 va = (void *) uvm_km_alloc(kmem_map, 389 (vsize_t)ctob(npg), 0, 390 ((flags & M_NOWAIT) ? UVM_KMF_NOWAIT : 0) | 391 ((flags & M_CANFAIL) ? UVM_KMF_CANFAIL : 0) | 392 UVM_KMF_WIRED); 393 splx(s); 394 if (__predict_false(va == NULL)) { 395 /* 396 * Kmem_malloc() can return NULL, even if it can 397 * wait, if there is no map space available, because 398 * it can't fix that problem. Neither can we, 399 * right now. (We should release pages which 400 * are completely free and which are in kmembuckets 401 * with too many free elements.) 402 */ 403 if ((flags & (M_NOWAIT|M_CANFAIL)) == 0) 404 panic("malloc: out of space in kmem_map"); 405 return (NULL); 406 } 407 mutex_spin_enter(&malloc_lock); 408 #ifdef KMEMSTATS 409 kbp->kb_total += kbp->kb_elmpercl; 410 #endif 411 kup = btokup(va); 412 kup->ku_indx = indx; 413 if (allocsize > MAXALLOCSAVE) { 414 if (npg > 65535) 415 panic("malloc: allocation too large"); 416 kup->ku_pagecnt = npg; 417 #ifdef KMEMSTATS 418 ksp->ks_memuse += allocsize; 419 #endif 420 goto out; 421 } 422 #ifdef KMEMSTATS 423 kup->ku_freecnt = kbp->kb_elmpercl; 424 kbp->kb_totalfree += kbp->kb_elmpercl; 425 #endif 426 /* 427 * Just in case we blocked while allocating memory, 428 * and someone else also allocated memory for this 429 * kmembucket, don't assume the list is still empty. 430 */ 431 savedlist = kbp->kb_next; 432 kbp->kb_next = cp = va + (npg << PAGE_SHIFT) - allocsize; 433 for (;;) { 434 freep = (struct freelist *)cp; 435 #ifdef DIAGNOSTIC 436 /* 437 * Copy in known text to detect modification 438 * after freeing. 439 */ 440 end = (uint32_t *)&cp[copysize]; 441 for (lp = (uint32_t *)cp; lp < end; lp++) 442 *lp = WEIRD_ADDR; 443 freep->type = M_FREE; 444 #endif /* DIAGNOSTIC */ 445 if (cp <= va) 446 break; 447 cp -= allocsize; 448 freep->next = cp; 449 } 450 freep->next = savedlist; 451 if (savedlist == NULL) 452 kbp->kb_last = (void *)freep; 453 } 454 va = kbp->kb_next; 455 kbp->kb_next = ((struct freelist *)va)->next; 456 #ifdef DIAGNOSTIC 457 freep = (struct freelist *)va; 458 /* XXX potential to get garbage pointer here. */ 459 if (kbp->kb_next) { 460 int rv; 461 vaddr_t addr = (vaddr_t)kbp->kb_next; 462 463 vm_map_lock(kmem_map); 464 rv = uvm_map_checkprot(kmem_map, addr, 465 addr + sizeof(struct freelist), VM_PROT_WRITE); 466 vm_map_unlock(kmem_map); 467 468 if (__predict_false(rv == 0)) { 469 printf("Data modified on freelist: " 470 "word %ld of object %p size %ld previous type %s " 471 "(invalid addr %p)\n", 472 (long)((int32_t *)&kbp->kb_next - (int32_t *)kbp), 473 va, size, "foo", kbp->kb_next); 474 #ifdef MALLOCLOG 475 hitmlog(va); 476 #endif 477 kbp->kb_next = NULL; 478 } 479 } 480 481 /* Fill the fields that we've used with WEIRD_ADDR */ 482 #ifdef _LP64 483 freep->type = (struct malloc_type *) 484 (WEIRD_ADDR | (((u_long) WEIRD_ADDR) << 32)); 485 #else 486 freep->type = (struct malloc_type *) WEIRD_ADDR; 487 #endif 488 end = (uint32_t *)&freep->next + 489 (sizeof(freep->next) / sizeof(int32_t)); 490 for (lp = (uint32_t *)&freep->next; lp < end; lp++) 491 *lp = WEIRD_ADDR; 492 493 /* and check that the data hasn't been modified. */ 494 end = (uint32_t *)&va[copysize]; 495 for (lp = (uint32_t *)va; lp < end; lp++) { 496 if (__predict_true(*lp == WEIRD_ADDR)) 497 continue; 498 printf("Data modified on freelist: " 499 "word %ld of object %p size %ld previous type %s " 500 "(0x%x != 0x%x)\n", 501 (long)(lp - (uint32_t *)va), va, size, 502 "bar", *lp, WEIRD_ADDR); 503 #ifdef MALLOCLOG 504 hitmlog(va); 505 #endif 506 break; 507 } 508 509 freep->spare0 = 0; 510 #endif /* DIAGNOSTIC */ 511 #ifdef KMEMSTATS 512 kup = btokup(va); 513 if (kup->ku_indx != indx) 514 panic("malloc: wrong bucket"); 515 if (kup->ku_freecnt == 0) 516 panic("malloc: lost data"); 517 kup->ku_freecnt--; 518 kbp->kb_totalfree--; 519 ksp->ks_memuse += 1 << indx; 520 out: 521 kbp->kb_calls++; 522 ksp->ks_inuse++; 523 ksp->ks_calls++; 524 if (ksp->ks_memuse > ksp->ks_maxused) 525 ksp->ks_maxused = ksp->ks_memuse; 526 #else 527 out: 528 #endif 529 #ifdef MALLOCLOG 530 domlog(va, size, ksp, 1, file, line); 531 #endif 532 mutex_spin_exit(&malloc_lock); 533 if ((flags & M_ZERO) != 0) 534 memset(va, 0, size); 535 FREECHECK_OUT(&malloc_freecheck, (void *)va); 536 return ((void *) va); 537 } 538 539 /* 540 * Free a block of memory allocated by malloc. 541 */ 542 #ifdef MALLOCLOG 543 void 544 _kern_free(void *addr, struct malloc_type *ksp, const char *file, long line) 545 #else 546 void 547 kern_free(void *addr, struct malloc_type *ksp) 548 #endif /* MALLOCLOG */ 549 { 550 struct kmembuckets *kbp; 551 struct kmemusage *kup; 552 struct freelist *freep; 553 long size; 554 #ifdef DIAGNOSTIC 555 void *cp; 556 int32_t *end, *lp; 557 long alloc, copysize; 558 #endif 559 560 FREECHECK_IN(&malloc_freecheck, addr); 561 #ifdef MALLOC_DEBUG 562 if (debug_free(addr, ksp)) 563 return; 564 #endif 565 566 #ifdef DIAGNOSTIC 567 /* 568 * Ensure that we're free'ing something that we could 569 * have allocated in the first place. That is, check 570 * to see that the address is within kmem_map. 571 */ 572 if (__predict_false((vaddr_t)addr < vm_map_min(kmem_map) || 573 (vaddr_t)addr >= vm_map_max(kmem_map))) 574 panic("free: addr %p not within kmem_map", addr); 575 #endif 576 577 kup = btokup(addr); 578 size = 1 << kup->ku_indx; 579 kbp = &kmembuckets[kup->ku_indx]; 580 581 LOCKDEBUG_MEM_CHECK(addr, 582 size <= MAXALLOCSAVE ? size : ctob(kup->ku_pagecnt)); 583 584 mutex_spin_enter(&malloc_lock); 585 #ifdef MALLOCLOG 586 domlog(addr, 0, ksp, 2, file, line); 587 #endif 588 #ifdef DIAGNOSTIC 589 /* 590 * Check for returns of data that do not point to the 591 * beginning of the allocation. 592 */ 593 if (size > PAGE_SIZE) 594 alloc = addrmask[BUCKETINDX(PAGE_SIZE)]; 595 else 596 alloc = addrmask[kup->ku_indx]; 597 if (((u_long)addr & alloc) != 0) 598 panic("free: unaligned addr %p, size %ld, type %s, mask %ld", 599 addr, size, ksp->ks_shortdesc, alloc); 600 #endif /* DIAGNOSTIC */ 601 if (size > MAXALLOCSAVE) { 602 uvm_km_free(kmem_map, (vaddr_t)addr, ctob(kup->ku_pagecnt), 603 UVM_KMF_WIRED); 604 #ifdef KMEMSTATS 605 size = kup->ku_pagecnt << PGSHIFT; 606 ksp->ks_memuse -= size; 607 kup->ku_indx = 0; 608 kup->ku_pagecnt = 0; 609 if (ksp->ks_memuse + size >= ksp->ks_limit && 610 ksp->ks_memuse < ksp->ks_limit) 611 wakeup((void *)ksp); 612 #ifdef DIAGNOSTIC 613 if (ksp->ks_inuse == 0) 614 panic("free 1: inuse 0, probable double free"); 615 #endif 616 ksp->ks_inuse--; 617 kbp->kb_total -= 1; 618 #endif 619 mutex_spin_exit(&malloc_lock); 620 return; 621 } 622 freep = (struct freelist *)addr; 623 #ifdef DIAGNOSTIC 624 /* 625 * Check for multiple frees. Use a quick check to see if 626 * it looks free before laboriously searching the freelist. 627 */ 628 if (__predict_false(freep->spare0 == WEIRD_ADDR)) { 629 for (cp = kbp->kb_next; cp; 630 cp = ((struct freelist *)cp)->next) { 631 if (addr != cp) 632 continue; 633 printf("multiply freed item %p\n", addr); 634 #ifdef MALLOCLOG 635 hitmlog(addr); 636 #endif 637 panic("free: duplicated free"); 638 } 639 } 640 641 /* 642 * Copy in known text to detect modification after freeing 643 * and to make it look free. Also, save the type being freed 644 * so we can list likely culprit if modification is detected 645 * when the object is reallocated. 646 */ 647 copysize = size < MAX_COPY ? size : MAX_COPY; 648 end = (int32_t *)&((char *)addr)[copysize]; 649 for (lp = (int32_t *)addr; lp < end; lp++) 650 *lp = WEIRD_ADDR; 651 freep->type = ksp; 652 #endif /* DIAGNOSTIC */ 653 #ifdef KMEMSTATS 654 kup->ku_freecnt++; 655 if (kup->ku_freecnt >= kbp->kb_elmpercl) { 656 if (kup->ku_freecnt > kbp->kb_elmpercl) 657 panic("free: multiple frees"); 658 else if (kbp->kb_totalfree > kbp->kb_highwat) 659 kbp->kb_couldfree++; 660 } 661 kbp->kb_totalfree++; 662 ksp->ks_memuse -= size; 663 if (ksp->ks_memuse + size >= ksp->ks_limit && 664 ksp->ks_memuse < ksp->ks_limit) 665 wakeup((void *)ksp); 666 #ifdef DIAGNOSTIC 667 if (ksp->ks_inuse == 0) 668 panic("free 2: inuse 0, probable double free"); 669 #endif 670 ksp->ks_inuse--; 671 #endif 672 if (kbp->kb_next == NULL) 673 kbp->kb_next = addr; 674 else 675 ((struct freelist *)kbp->kb_last)->next = addr; 676 freep->next = NULL; 677 kbp->kb_last = addr; 678 mutex_spin_exit(&malloc_lock); 679 } 680 681 /* 682 * Change the size of a block of memory. 683 */ 684 void * 685 kern_realloc(void *curaddr, unsigned long newsize, struct malloc_type *ksp, 686 int flags) 687 { 688 struct kmemusage *kup; 689 unsigned long cursize; 690 void *newaddr; 691 #ifdef DIAGNOSTIC 692 long alloc; 693 #endif 694 695 /* 696 * realloc() with a NULL pointer is the same as malloc(). 697 */ 698 if (curaddr == NULL) 699 return (malloc(newsize, ksp, flags)); 700 701 /* 702 * realloc() with zero size is the same as free(). 703 */ 704 if (newsize == 0) { 705 free(curaddr, ksp); 706 return (NULL); 707 } 708 709 #ifdef LOCKDEBUG 710 if ((flags & M_NOWAIT) == 0) { 711 ASSERT_SLEEPABLE(); 712 } 713 #endif 714 715 /* 716 * Find out how large the old allocation was (and do some 717 * sanity checking). 718 */ 719 kup = btokup(curaddr); 720 cursize = 1 << kup->ku_indx; 721 722 #ifdef DIAGNOSTIC 723 /* 724 * Check for returns of data that do not point to the 725 * beginning of the allocation. 726 */ 727 if (cursize > PAGE_SIZE) 728 alloc = addrmask[BUCKETINDX(PAGE_SIZE)]; 729 else 730 alloc = addrmask[kup->ku_indx]; 731 if (((u_long)curaddr & alloc) != 0) 732 panic("realloc: " 733 "unaligned addr %p, size %ld, type %s, mask %ld\n", 734 curaddr, cursize, ksp->ks_shortdesc, alloc); 735 #endif /* DIAGNOSTIC */ 736 737 if (cursize > MAXALLOCSAVE) 738 cursize = ctob(kup->ku_pagecnt); 739 740 /* 741 * If we already actually have as much as they want, we're done. 742 */ 743 if (newsize <= cursize) 744 return (curaddr); 745 746 /* 747 * Can't satisfy the allocation with the existing block. 748 * Allocate a new one and copy the data. 749 */ 750 newaddr = malloc(newsize, ksp, flags); 751 if (__predict_false(newaddr == NULL)) { 752 /* 753 * malloc() failed, because flags included M_NOWAIT. 754 * Return NULL to indicate that failure. The old 755 * pointer is still valid. 756 */ 757 return (NULL); 758 } 759 memcpy(newaddr, curaddr, cursize); 760 761 /* 762 * We were successful: free the old allocation and return 763 * the new one. 764 */ 765 free(curaddr, ksp); 766 return (newaddr); 767 } 768 769 /* 770 * Roundup size to the actual allocation size. 771 */ 772 unsigned long 773 malloc_roundup(unsigned long size) 774 { 775 776 if (size > MAXALLOCSAVE) 777 return (roundup(size, PAGE_SIZE)); 778 else 779 return (1 << BUCKETINDX(size)); 780 } 781 782 /* 783 * Add a malloc type to the system. 784 */ 785 void 786 malloc_type_attach(struct malloc_type *type) 787 { 788 789 if (nkmempages == 0) 790 panic("malloc_type_attach: nkmempages == 0"); 791 792 if (type->ks_magic != M_MAGIC) 793 panic("malloc_type_attach: bad magic"); 794 795 #ifdef DIAGNOSTIC 796 { 797 struct malloc_type *ksp; 798 for (ksp = kmemstatistics; ksp != NULL; ksp = ksp->ks_next) { 799 if (ksp == type) 800 panic("malloc_type_attach: already on list"); 801 } 802 } 803 #endif 804 805 #ifdef KMEMSTATS 806 if (type->ks_limit == 0) 807 type->ks_limit = ((u_long)nkmempages << PAGE_SHIFT) * 6U / 10U; 808 #else 809 type->ks_limit = 0; 810 #endif 811 812 type->ks_next = kmemstatistics; 813 kmemstatistics = type; 814 } 815 816 /* 817 * Remove a malloc type from the system.. 818 */ 819 void 820 malloc_type_detach(struct malloc_type *type) 821 { 822 struct malloc_type *ksp; 823 824 #ifdef DIAGNOSTIC 825 if (type->ks_magic != M_MAGIC) 826 panic("malloc_type_detach: bad magic"); 827 #endif 828 829 if (type == kmemstatistics) 830 kmemstatistics = type->ks_next; 831 else { 832 for (ksp = kmemstatistics; ksp->ks_next != NULL; 833 ksp = ksp->ks_next) { 834 if (ksp->ks_next == type) { 835 ksp->ks_next = type->ks_next; 836 break; 837 } 838 } 839 #ifdef DIAGNOSTIC 840 if (ksp->ks_next == NULL) 841 panic("malloc_type_detach: not on list"); 842 #endif 843 } 844 type->ks_next = NULL; 845 } 846 847 /* 848 * Set the limit on a malloc type. 849 */ 850 void 851 malloc_type_setlimit(struct malloc_type *type, u_long limit) 852 { 853 #ifdef KMEMSTATS 854 mutex_spin_enter(&malloc_lock); 855 type->ks_limit = limit; 856 mutex_spin_exit(&malloc_lock); 857 #endif 858 } 859 860 /* 861 * Compute the number of pages that kmem_map will map, that is, 862 * the size of the kernel malloc arena. 863 */ 864 void 865 kmeminit_nkmempages(void) 866 { 867 int npages; 868 869 if (nkmempages != 0) { 870 /* 871 * It's already been set (by us being here before, or 872 * by patching or kernel config options), bail out now. 873 */ 874 return; 875 } 876 877 npages = physmem; 878 879 if (npages > NKMEMPAGES_MAX) 880 npages = NKMEMPAGES_MAX; 881 882 if (npages < NKMEMPAGES_MIN) 883 npages = NKMEMPAGES_MIN; 884 885 nkmempages = npages; 886 } 887 888 /* 889 * Initialize the kernel memory allocator 890 */ 891 void 892 kmeminit(void) 893 { 894 __link_set_decl(malloc_types, struct malloc_type); 895 struct malloc_type * const *ksp; 896 vaddr_t kmb, kml; 897 #ifdef KMEMSTATS 898 long indx; 899 #endif 900 901 #if ((MAXALLOCSAVE & (MAXALLOCSAVE - 1)) != 0) 902 ERROR!_kmeminit:_MAXALLOCSAVE_not_power_of_2 903 #endif 904 #if (MAXALLOCSAVE > MINALLOCSIZE * 32768) 905 ERROR!_kmeminit:_MAXALLOCSAVE_too_big 906 #endif 907 #if (MAXALLOCSAVE < NBPG) 908 ERROR!_kmeminit:_MAXALLOCSAVE_too_small 909 #endif 910 911 if (sizeof(struct freelist) > (1 << MINBUCKET)) 912 panic("minbucket too small/struct freelist too big"); 913 914 mutex_init(&malloc_lock, MUTEX_DEFAULT, IPL_VM); 915 916 /* 917 * Compute the number of kmem_map pages, if we have not 918 * done so already. 919 */ 920 kmeminit_nkmempages(); 921 922 kmemusage = (struct kmemusage *) uvm_km_alloc(kernel_map, 923 (vsize_t)(nkmempages * sizeof(struct kmemusage)), 0, 924 UVM_KMF_WIRED|UVM_KMF_ZERO); 925 kmb = 0; 926 kmem_map = uvm_km_suballoc(kernel_map, &kmb, 927 &kml, ((vsize_t)nkmempages << PAGE_SHIFT), 928 VM_MAP_INTRSAFE, false, &kmem_map_store); 929 uvm_km_vacache_init(kmem_map, "kvakmem", 0); 930 kmembase = (char *)kmb; 931 kmemlimit = (char *)kml; 932 #ifdef KMEMSTATS 933 for (indx = 0; indx < MINBUCKET + 16; indx++) { 934 if (1 << indx >= PAGE_SIZE) 935 kmembuckets[indx].kb_elmpercl = 1; 936 else 937 kmembuckets[indx].kb_elmpercl = PAGE_SIZE / (1 << indx); 938 kmembuckets[indx].kb_highwat = 939 5 * kmembuckets[indx].kb_elmpercl; 940 } 941 #endif 942 943 /* Attach all of the statically-linked malloc types. */ 944 __link_set_foreach(ksp, malloc_types) 945 malloc_type_attach(*ksp); 946 947 #ifdef MALLOC_DEBUG 948 debug_malloc_init(); 949 #endif 950 } 951 952 #ifdef DDB 953 #include <ddb/db_output.h> 954 955 /* 956 * Dump kmem statistics from ddb. 957 * 958 * usage: call dump_kmemstats 959 */ 960 void dump_kmemstats(void); 961 962 void 963 dump_kmemstats(void) 964 { 965 #ifdef KMEMSTATS 966 struct malloc_type *ksp; 967 968 for (ksp = kmemstatistics; ksp != NULL; ksp = ksp->ks_next) { 969 if (ksp->ks_memuse == 0) 970 continue; 971 db_printf("%s%.*s %ld\n", ksp->ks_shortdesc, 972 (int)(20 - strlen(ksp->ks_shortdesc)), 973 " ", 974 ksp->ks_memuse); 975 } 976 #else 977 db_printf("Kmem stats are not being collected.\n"); 978 #endif /* KMEMSTATS */ 979 } 980 #endif /* DDB */ 981 982 983 #if 0 984 /* 985 * Diagnostic messages about "Data modified on 986 * freelist" indicate a memory corruption, but 987 * they do not help tracking it down. 988 * This function can be called at various places 989 * to sanity check malloc's freelist and discover 990 * where does the corruption take place. 991 */ 992 int 993 freelist_sanitycheck(void) { 994 int i,j; 995 struct kmembuckets *kbp; 996 struct freelist *freep; 997 int rv = 0; 998 999 for (i = MINBUCKET; i <= MINBUCKET + 15; i++) { 1000 kbp = &kmembuckets[i]; 1001 freep = (struct freelist *)kbp->kb_next; 1002 j = 0; 1003 while(freep) { 1004 vm_map_lock(kmem_map); 1005 rv = uvm_map_checkprot(kmem_map, (vaddr_t)freep, 1006 (vaddr_t)freep + sizeof(struct freelist), 1007 VM_PROT_WRITE); 1008 vm_map_unlock(kmem_map); 1009 1010 if ((rv == 0) || (*(int *)freep != WEIRD_ADDR)) { 1011 printf("bucket %i, chunck %d at %p modified\n", 1012 i, j, freep); 1013 return 1; 1014 } 1015 freep = (struct freelist *)freep->next; 1016 j++; 1017 } 1018 } 1019 1020 return 0; 1021 } 1022 #endif 1023
Indexes created Sat Sep 20 22:09:52 GMT 2025