1 /* $NetBSD: kern_malloc.c,v 1.114 2007/11/11 23:22:23 matt 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 1.114 2007/11/11 23:22:23 matt 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 static void 196 domlog(void *a, long size, struct malloc_type *type, int action, 197 const char *file, long line) 198 { 199 200 malloclog[malloclogptr].addr = a; 201 malloclog[malloclogptr].size = size; 202 malloclog[malloclogptr].type = type; 203 malloclog[malloclogptr].action = action; 204 malloclog[malloclogptr].file = file; 205 malloclog[malloclogptr].line = line; 206 malloclogptr++; 207 if (malloclogptr >= MALLOCLOGSIZE) 208 malloclogptr = 0; 209 } 210 211 static void 212 hitmlog(void *a) 213 { 214 struct malloclog *lp; 215 long l; 216 217 #define PRT do { \ 218 lp = &malloclog[l]; \ 219 if (lp->addr == a && lp->action) { \ 220 printf("malloc log entry %ld:\n", l); \ 221 printf("\taddr = %p\n", lp->addr); \ 222 printf("\tsize = %ld\n", lp->size); \ 223 printf("\ttype = %s\n", lp->type->ks_shortdesc); \ 224 printf("\taction = %s\n", lp->action == 1 ? "alloc" : "free"); \ 225 printf("\tfile = %s\n", lp->file); \ 226 printf("\tline = %ld\n", lp->line); \ 227 } \ 228 } while (/* CONSTCOND */0) 229 230 for (l = malloclogptr; l < MALLOCLOGSIZE; l++) 231 PRT; 232 233 for (l = 0; l < malloclogptr; l++) 234 PRT; 235 #undef PRT 236 } 237 #endif /* MALLOCLOG */ 238 239 #ifdef DIAGNOSTIC 240 /* 241 * This structure provides a set of masks to catch unaligned frees. 242 */ 243 const long addrmask[] = { 0, 244 0x00000001, 0x00000003, 0x00000007, 0x0000000f, 245 0x0000001f, 0x0000003f, 0x0000007f, 0x000000ff, 246 0x000001ff, 0x000003ff, 0x000007ff, 0x00000fff, 247 0x00001fff, 0x00003fff, 0x00007fff, 0x0000ffff, 248 }; 249 250 /* 251 * The WEIRD_ADDR is used as known text to copy into free objects so 252 * that modifications after frees can be detected. 253 */ 254 #define WEIRD_ADDR ((uint32_t) 0xdeadbeef) 255 #ifdef DEBUG 256 #define MAX_COPY PAGE_SIZE 257 #else 258 #define MAX_COPY 32 259 #endif 260 261 /* 262 * Normally the freelist structure is used only to hold the list pointer 263 * for free objects. However, when running with diagnostics, the first 264 * 8/16 bytes of the structure is unused except for diagnostic information, 265 * and the free list pointer is at offset 8/16 in the structure. Since the 266 * first 8 bytes is the portion of the structure most often modified, this 267 * helps to detect memory reuse problems and avoid free list corruption. 268 */ 269 struct freelist { 270 uint32_t spare0; 271 #ifdef _LP64 272 uint32_t spare1; /* explicit padding */ 273 #endif 274 struct malloc_type *type; 275 void * next; 276 }; 277 #else /* !DIAGNOSTIC */ 278 struct freelist { 279 void * next; 280 }; 281 #endif /* DIAGNOSTIC */ 282 283 /* 284 * The following are standard, built-in malloc types and are not 285 * specific to any subsystem. 286 */ 287 MALLOC_DEFINE(M_DEVBUF, "devbuf", "device driver memory"); 288 MALLOC_DEFINE(M_DMAMAP, "DMA map", "bus_dma(9) structures"); 289 MALLOC_DEFINE(M_FREE, "free", "should be on free list"); 290 MALLOC_DEFINE(M_PCB, "pcb", "protocol control block"); 291 MALLOC_DEFINE(M_SOFTINTR, "softintr", "Softinterrupt structures"); 292 MALLOC_DEFINE(M_TEMP, "temp", "misc. temporary data buffers"); 293 294 /* XXX These should all be elsewhere. */ 295 MALLOC_DEFINE(M_RTABLE, "routetbl", "routing tables"); 296 MALLOC_DEFINE(M_FTABLE, "fragtbl", "fragment reassembly header"); 297 MALLOC_DEFINE(M_UFSMNT, "UFS mount", "UFS mount structure"); 298 MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure"); 299 MALLOC_DEFINE(M_IPMOPTS, "ip_moptions", "internet multicast options"); 300 MALLOC_DEFINE(M_IPMADDR, "in_multi", "internet multicast address"); 301 MALLOC_DEFINE(M_MRTABLE, "mrt", "multicast routing tables"); 302 MALLOC_DEFINE(M_BWMETER, "bwmeter", "multicast upcall bw meters"); 303 MALLOC_DEFINE(M_1394DATA, "1394data", "IEEE 1394 data buffers"); 304 305 kmutex_t malloc_lock; 306 307 /* 308 * Allocate a block of memory 309 */ 310 #ifdef MALLOCLOG 311 void * 312 _malloc(unsigned long size, struct malloc_type *ksp, int flags, 313 const char *file, long line) 314 #else 315 void * 316 malloc(unsigned long size, struct malloc_type *ksp, int flags) 317 #endif /* MALLOCLOG */ 318 { 319 struct kmembuckets *kbp; 320 struct kmemusage *kup; 321 struct freelist *freep; 322 long indx, npg, allocsize; 323 char *va, *cp, *savedlist; 324 #ifdef DIAGNOSTIC 325 uint32_t *end, *lp; 326 int copysize; 327 #endif 328 329 #ifdef LOCKDEBUG 330 if ((flags & M_NOWAIT) == 0) 331 ASSERT_SLEEPABLE(NULL, "malloc"); 332 #endif 333 #ifdef MALLOC_DEBUG 334 if (debug_malloc(size, ksp, flags, (void *) &va)) { 335 if (va != 0) 336 FREECHECK_OUT(&malloc_freecheck, (void *)va); 337 return ((void *) va); 338 } 339 #endif 340 indx = BUCKETINDX(size); 341 kbp = &kmembuckets[indx]; 342 mutex_spin_enter(&malloc_lock); 343 #ifdef KMEMSTATS 344 while (ksp->ks_memuse >= ksp->ks_limit) { 345 if (flags & M_NOWAIT) { 346 mutex_spin_exit(&malloc_lock); 347 return ((void *) NULL); 348 } 349 if (ksp->ks_limblocks < 65535) 350 ksp->ks_limblocks++; 351 mtsleep((void *)ksp, PSWP+2, ksp->ks_shortdesc, 0, 352 &malloc_lock); 353 } 354 ksp->ks_size |= 1 << indx; 355 #endif 356 #ifdef DIAGNOSTIC 357 copysize = 1 << indx < MAX_COPY ? 1 << indx : MAX_COPY; 358 #endif 359 if (kbp->kb_next == NULL) { 360 int s; 361 kbp->kb_last = NULL; 362 if (size > MAXALLOCSAVE) 363 allocsize = round_page(size); 364 else 365 allocsize = 1 << indx; 366 npg = btoc(allocsize); 367 mutex_spin_exit(&malloc_lock); 368 s = splvm(); 369 va = (void *) uvm_km_alloc(kmem_map, 370 (vsize_t)ctob(npg), 0, 371 ((flags & M_NOWAIT) ? UVM_KMF_NOWAIT : 0) | 372 ((flags & M_CANFAIL) ? UVM_KMF_CANFAIL : 0) | 373 UVM_KMF_WIRED); 374 splx(s); 375 if (__predict_false(va == NULL)) { 376 /* 377 * Kmem_malloc() can return NULL, even if it can 378 * wait, if there is no map space available, because 379 * it can't fix that problem. Neither can we, 380 * right now. (We should release pages which 381 * are completely free and which are in kmembuckets 382 * with too many free elements.) 383 */ 384 if ((flags & (M_NOWAIT|M_CANFAIL)) == 0) 385 panic("malloc: out of space in kmem_map"); 386 return (NULL); 387 } 388 mutex_spin_enter(&malloc_lock); 389 #ifdef KMEMSTATS 390 kbp->kb_total += kbp->kb_elmpercl; 391 #endif 392 kup = btokup(va); 393 kup->ku_indx = indx; 394 if (allocsize > MAXALLOCSAVE) { 395 if (npg > 65535) 396 panic("malloc: allocation too large"); 397 kup->ku_pagecnt = npg; 398 #ifdef KMEMSTATS 399 ksp->ks_memuse += allocsize; 400 #endif 401 goto out; 402 } 403 #ifdef KMEMSTATS 404 kup->ku_freecnt = kbp->kb_elmpercl; 405 kbp->kb_totalfree += kbp->kb_elmpercl; 406 #endif 407 /* 408 * Just in case we blocked while allocating memory, 409 * and someone else also allocated memory for this 410 * kmembucket, don't assume the list is still empty. 411 */ 412 savedlist = kbp->kb_next; 413 kbp->kb_next = cp = va + (npg << PAGE_SHIFT) - allocsize; 414 for (;;) { 415 freep = (struct freelist *)cp; 416 #ifdef DIAGNOSTIC 417 /* 418 * Copy in known text to detect modification 419 * after freeing. 420 */ 421 end = (uint32_t *)&cp[copysize]; 422 for (lp = (uint32_t *)cp; lp < end; lp++) 423 *lp = WEIRD_ADDR; 424 freep->type = M_FREE; 425 #endif /* DIAGNOSTIC */ 426 if (cp <= va) 427 break; 428 cp -= allocsize; 429 freep->next = cp; 430 } 431 freep->next = savedlist; 432 if (kbp->kb_last == NULL) 433 kbp->kb_last = (void *)freep; 434 } 435 va = kbp->kb_next; 436 kbp->kb_next = ((struct freelist *)va)->next; 437 #ifdef DIAGNOSTIC 438 freep = (struct freelist *)va; 439 /* XXX potential to get garbage pointer here. */ 440 if (kbp->kb_next) { 441 int rv; 442 vaddr_t addr = (vaddr_t)kbp->kb_next; 443 444 vm_map_lock(kmem_map); 445 rv = uvm_map_checkprot(kmem_map, addr, 446 addr + sizeof(struct freelist), VM_PROT_WRITE); 447 vm_map_unlock(kmem_map); 448 449 if (__predict_false(rv == 0)) { 450 printf("Data modified on freelist: " 451 "word %ld of object %p size %ld previous type %s " 452 "(invalid addr %p)\n", 453 (long)((int32_t *)&kbp->kb_next - (int32_t *)kbp), 454 va, size, "foo", kbp->kb_next); 455 #ifdef MALLOCLOG 456 hitmlog(va); 457 #endif 458 kbp->kb_next = NULL; 459 } 460 } 461 462 /* Fill the fields that we've used with WEIRD_ADDR */ 463 #ifdef _LP64 464 freep->type = (struct malloc_type *) 465 (WEIRD_ADDR | (((u_long) WEIRD_ADDR) << 32)); 466 #else 467 freep->type = (struct malloc_type *) WEIRD_ADDR; 468 #endif 469 end = (uint32_t *)&freep->next + 470 (sizeof(freep->next) / sizeof(int32_t)); 471 for (lp = (uint32_t *)&freep->next; lp < end; lp++) 472 *lp = WEIRD_ADDR; 473 474 /* and check that the data hasn't been modified. */ 475 end = (uint32_t *)&va[copysize]; 476 for (lp = (uint32_t *)va; lp < end; lp++) { 477 if (__predict_true(*lp == WEIRD_ADDR)) 478 continue; 479 printf("Data modified on freelist: " 480 "word %ld of object %p size %ld previous type %s " 481 "(0x%x != 0x%x)\n", 482 (long)(lp - (uint32_t *)va), va, size, 483 "bar", *lp, WEIRD_ADDR); 484 #ifdef MALLOCLOG 485 hitmlog(va); 486 #endif 487 break; 488 } 489 490 freep->spare0 = 0; 491 #endif /* DIAGNOSTIC */ 492 #ifdef KMEMSTATS 493 kup = btokup(va); 494 if (kup->ku_indx != indx) 495 panic("malloc: wrong bucket"); 496 if (kup->ku_freecnt == 0) 497 panic("malloc: lost data"); 498 kup->ku_freecnt--; 499 kbp->kb_totalfree--; 500 ksp->ks_memuse += 1 << indx; 501 out: 502 kbp->kb_calls++; 503 ksp->ks_inuse++; 504 ksp->ks_calls++; 505 if (ksp->ks_memuse > ksp->ks_maxused) 506 ksp->ks_maxused = ksp->ks_memuse; 507 #else 508 out: 509 #endif 510 #ifdef MALLOCLOG 511 domlog(va, size, ksp, 1, file, line); 512 #endif 513 mutex_spin_exit(&malloc_lock); 514 if ((flags & M_ZERO) != 0) 515 memset(va, 0, size); 516 FREECHECK_OUT(&malloc_freecheck, (void *)va); 517 return ((void *) va); 518 } 519 520 /* 521 * Free a block of memory allocated by malloc. 522 */ 523 #ifdef MALLOCLOG 524 void 525 _free(void *addr, struct malloc_type *ksp, const char *file, long line) 526 #else 527 void 528 free(void *addr, struct malloc_type *ksp) 529 #endif /* MALLOCLOG */ 530 { 531 struct kmembuckets *kbp; 532 struct kmemusage *kup; 533 struct freelist *freep; 534 long size; 535 #ifdef DIAGNOSTIC 536 void *cp; 537 int32_t *end, *lp; 538 long alloc, copysize; 539 #endif 540 541 FREECHECK_IN(&malloc_freecheck, addr); 542 #ifdef MALLOC_DEBUG 543 if (debug_free(addr, ksp)) 544 return; 545 #endif 546 547 #ifdef DIAGNOSTIC 548 /* 549 * Ensure that we're free'ing something that we could 550 * have allocated in the first place. That is, check 551 * to see that the address is within kmem_map. 552 */ 553 if (__predict_false((vaddr_t)addr < vm_map_min(kmem_map) || 554 (vaddr_t)addr >= vm_map_max(kmem_map))) 555 panic("free: addr %p not within kmem_map", addr); 556 #endif 557 558 kup = btokup(addr); 559 size = 1 << kup->ku_indx; 560 kbp = &kmembuckets[kup->ku_indx]; 561 562 LOCKDEBUG_MEM_CHECK(addr, size); 563 564 mutex_spin_enter(&malloc_lock); 565 #ifdef MALLOCLOG 566 domlog(addr, 0, ksp, 2, file, line); 567 #endif 568 #ifdef DIAGNOSTIC 569 /* 570 * Check for returns of data that do not point to the 571 * beginning of the allocation. 572 */ 573 if (size > PAGE_SIZE) 574 alloc = addrmask[BUCKETINDX(PAGE_SIZE)]; 575 else 576 alloc = addrmask[kup->ku_indx]; 577 if (((u_long)addr & alloc) != 0) 578 panic("free: unaligned addr %p, size %ld, type %s, mask %ld", 579 addr, size, ksp->ks_shortdesc, alloc); 580 #endif /* DIAGNOSTIC */ 581 if (size > MAXALLOCSAVE) { 582 uvm_km_free(kmem_map, (vaddr_t)addr, ctob(kup->ku_pagecnt), 583 UVM_KMF_WIRED); 584 #ifdef KMEMSTATS 585 size = kup->ku_pagecnt << PGSHIFT; 586 ksp->ks_memuse -= size; 587 kup->ku_indx = 0; 588 kup->ku_pagecnt = 0; 589 if (ksp->ks_memuse + size >= ksp->ks_limit && 590 ksp->ks_memuse < ksp->ks_limit) 591 wakeup((void *)ksp); 592 #ifdef DIAGNOSTIC 593 if (ksp->ks_inuse == 0) 594 panic("free 1: inuse 0, probable double free"); 595 #endif 596 ksp->ks_inuse--; 597 kbp->kb_total -= 1; 598 #endif 599 mutex_spin_exit(&malloc_lock); 600 return; 601 } 602 freep = (struct freelist *)addr; 603 #ifdef DIAGNOSTIC 604 /* 605 * Check for multiple frees. Use a quick check to see if 606 * it looks free before laboriously searching the freelist. 607 */ 608 if (__predict_false(freep->spare0 == WEIRD_ADDR)) { 609 for (cp = kbp->kb_next; cp; 610 cp = ((struct freelist *)cp)->next) { 611 if (addr != cp) 612 continue; 613 printf("multiply freed item %p\n", addr); 614 #ifdef MALLOCLOG 615 hitmlog(addr); 616 #endif 617 panic("free: duplicated free"); 618 } 619 } 620 621 /* 622 * Copy in known text to detect modification after freeing 623 * and to make it look free. Also, save the type being freed 624 * so we can list likely culprit if modification is detected 625 * when the object is reallocated. 626 */ 627 copysize = size < MAX_COPY ? size : MAX_COPY; 628 end = (int32_t *)&((char *)addr)[copysize]; 629 for (lp = (int32_t *)addr; lp < end; lp++) 630 *lp = WEIRD_ADDR; 631 freep->type = ksp; 632 #endif /* DIAGNOSTIC */ 633 #ifdef KMEMSTATS 634 kup->ku_freecnt++; 635 if (kup->ku_freecnt >= kbp->kb_elmpercl) { 636 if (kup->ku_freecnt > kbp->kb_elmpercl) 637 panic("free: multiple frees"); 638 else if (kbp->kb_totalfree > kbp->kb_highwat) 639 kbp->kb_couldfree++; 640 } 641 kbp->kb_totalfree++; 642 ksp->ks_memuse -= size; 643 if (ksp->ks_memuse + size >= ksp->ks_limit && 644 ksp->ks_memuse < ksp->ks_limit) 645 wakeup((void *)ksp); 646 #ifdef DIAGNOSTIC 647 if (ksp->ks_inuse == 0) 648 panic("free 2: inuse 0, probable double free"); 649 #endif 650 ksp->ks_inuse--; 651 #endif 652 if (kbp->kb_next == NULL) 653 kbp->kb_next = addr; 654 else 655 ((struct freelist *)kbp->kb_last)->next = addr; 656 freep->next = NULL; 657 kbp->kb_last = addr; 658 mutex_spin_exit(&malloc_lock); 659 } 660 661 /* 662 * Change the size of a block of memory. 663 */ 664 void * 665 realloc(void *curaddr, unsigned long newsize, struct malloc_type *ksp, 666 int flags) 667 { 668 struct kmemusage *kup; 669 unsigned long cursize; 670 void *newaddr; 671 #ifdef DIAGNOSTIC 672 long alloc; 673 #endif 674 675 /* 676 * realloc() with a NULL pointer is the same as malloc(). 677 */ 678 if (curaddr == NULL) 679 return (malloc(newsize, ksp, flags)); 680 681 /* 682 * realloc() with zero size is the same as free(). 683 */ 684 if (newsize == 0) { 685 free(curaddr, ksp); 686 return (NULL); 687 } 688 689 #ifdef LOCKDEBUG 690 if ((flags & M_NOWAIT) == 0) 691 ASSERT_SLEEPABLE(NULL, "realloc"); 692 #endif 693 694 /* 695 * Find out how large the old allocation was (and do some 696 * sanity checking). 697 */ 698 kup = btokup(curaddr); 699 cursize = 1 << kup->ku_indx; 700 701 #ifdef DIAGNOSTIC 702 /* 703 * Check for returns of data that do not point to the 704 * beginning of the allocation. 705 */ 706 if (cursize > PAGE_SIZE) 707 alloc = addrmask[BUCKETINDX(PAGE_SIZE)]; 708 else 709 alloc = addrmask[kup->ku_indx]; 710 if (((u_long)curaddr & alloc) != 0) 711 panic("realloc: " 712 "unaligned addr %p, size %ld, type %s, mask %ld\n", 713 curaddr, cursize, ksp->ks_shortdesc, alloc); 714 #endif /* DIAGNOSTIC */ 715 716 if (cursize > MAXALLOCSAVE) 717 cursize = ctob(kup->ku_pagecnt); 718 719 /* 720 * If we already actually have as much as they want, we're done. 721 */ 722 if (newsize <= cursize) 723 return (curaddr); 724 725 /* 726 * Can't satisfy the allocation with the existing block. 727 * Allocate a new one and copy the data. 728 */ 729 newaddr = malloc(newsize, ksp, flags); 730 if (__predict_false(newaddr == NULL)) { 731 /* 732 * malloc() failed, because flags included M_NOWAIT. 733 * Return NULL to indicate that failure. The old 734 * pointer is still valid. 735 */ 736 return (NULL); 737 } 738 memcpy(newaddr, curaddr, cursize); 739 740 /* 741 * We were successful: free the old allocation and return 742 * the new one. 743 */ 744 free(curaddr, ksp); 745 return (newaddr); 746 } 747 748 /* 749 * Roundup size to the actual allocation size. 750 */ 751 unsigned long 752 malloc_roundup(unsigned long size) 753 { 754 755 if (size > MAXALLOCSAVE) 756 return (roundup(size, PAGE_SIZE)); 757 else 758 return (1 << BUCKETINDX(size)); 759 } 760 761 /* 762 * Add a malloc type to the system. 763 */ 764 void 765 malloc_type_attach(struct malloc_type *type) 766 { 767 768 if (nkmempages == 0) 769 panic("malloc_type_attach: nkmempages == 0"); 770 771 if (type->ks_magic != M_MAGIC) 772 panic("malloc_type_attach: bad magic"); 773 774 #ifdef DIAGNOSTIC 775 { 776 struct malloc_type *ksp; 777 for (ksp = kmemstatistics; ksp != NULL; ksp = ksp->ks_next) { 778 if (ksp == type) 779 panic("malloc_type_attach: already on list"); 780 } 781 } 782 #endif 783 784 #ifdef KMEMSTATS 785 if (type->ks_limit == 0) 786 type->ks_limit = ((u_long)nkmempages << PAGE_SHIFT) * 6U / 10U; 787 #else 788 type->ks_limit = 0; 789 #endif 790 791 type->ks_next = kmemstatistics; 792 kmemstatistics = type; 793 } 794 795 /* 796 * Remove a malloc type from the system.. 797 */ 798 void 799 malloc_type_detach(struct malloc_type *type) 800 { 801 struct malloc_type *ksp; 802 803 #ifdef DIAGNOSTIC 804 if (type->ks_magic != M_MAGIC) 805 panic("malloc_type_detach: bad magic"); 806 #endif 807 808 if (type == kmemstatistics) 809 kmemstatistics = type->ks_next; 810 else { 811 for (ksp = kmemstatistics; ksp->ks_next != NULL; 812 ksp = ksp->ks_next) { 813 if (ksp->ks_next == type) { 814 ksp->ks_next = type->ks_next; 815 break; 816 } 817 } 818 #ifdef DIAGNOSTIC 819 if (ksp->ks_next == NULL) 820 panic("malloc_type_detach: not on list"); 821 #endif 822 } 823 type->ks_next = NULL; 824 } 825 826 /* 827 * Set the limit on a malloc type. 828 */ 829 void 830 malloc_type_setlimit(struct malloc_type *type, u_long limit) 831 { 832 #ifdef KMEMSTATS 833 mutex_spin_enter(&malloc_lock); 834 type->ks_limit = limit; 835 mutex_spin_exit(&malloc_lock); 836 #endif 837 } 838 839 /* 840 * Compute the number of pages that kmem_map will map, that is, 841 * the size of the kernel malloc arena. 842 */ 843 void 844 kmeminit_nkmempages(void) 845 { 846 int npages; 847 848 if (nkmempages != 0) { 849 /* 850 * It's already been set (by us being here before, or 851 * by patching or kernel config options), bail out now. 852 */ 853 return; 854 } 855 856 npages = physmem; 857 858 if (npages > NKMEMPAGES_MAX) 859 npages = NKMEMPAGES_MAX; 860 861 if (npages < NKMEMPAGES_MIN) 862 npages = NKMEMPAGES_MIN; 863 864 nkmempages = npages; 865 } 866 867 /* 868 * Initialize the kernel memory allocator 869 */ 870 void 871 kmeminit(void) 872 { 873 __link_set_decl(malloc_types, struct malloc_type); 874 struct malloc_type * const *ksp; 875 vaddr_t kmb, kml; 876 #ifdef KMEMSTATS 877 long indx; 878 #endif 879 880 #if ((MAXALLOCSAVE & (MAXALLOCSAVE - 1)) != 0) 881 ERROR!_kmeminit:_MAXALLOCSAVE_not_power_of_2 882 #endif 883 #if (MAXALLOCSAVE > MINALLOCSIZE * 32768) 884 ERROR!_kmeminit:_MAXALLOCSAVE_too_big 885 #endif 886 #if (MAXALLOCSAVE < NBPG) 887 ERROR!_kmeminit:_MAXALLOCSAVE_too_small 888 #endif 889 890 if (sizeof(struct freelist) > (1 << MINBUCKET)) 891 panic("minbucket too small/struct freelist too big"); 892 893 mutex_init(&malloc_lock, MUTEX_DRIVER, IPL_VM); 894 895 /* 896 * Compute the number of kmem_map pages, if we have not 897 * done so already. 898 */ 899 kmeminit_nkmempages(); 900 901 kmemusage = (struct kmemusage *) uvm_km_alloc(kernel_map, 902 (vsize_t)(nkmempages * sizeof(struct kmemusage)), 0, 903 UVM_KMF_WIRED|UVM_KMF_ZERO); 904 kmb = 0; 905 kmem_map = uvm_km_suballoc(kernel_map, &kmb, 906 &kml, ((vsize_t)nkmempages << PAGE_SHIFT), 907 VM_MAP_INTRSAFE, false, &kmem_map_store); 908 uvm_km_vacache_init(kmem_map, "kvakmem", 0); 909 kmembase = (char *)kmb; 910 kmemlimit = (char *)kml; 911 #ifdef KMEMSTATS 912 for (indx = 0; indx < MINBUCKET + 16; indx++) { 913 if (1 << indx >= PAGE_SIZE) 914 kmembuckets[indx].kb_elmpercl = 1; 915 else 916 kmembuckets[indx].kb_elmpercl = PAGE_SIZE / (1 << indx); 917 kmembuckets[indx].kb_highwat = 918 5 * kmembuckets[indx].kb_elmpercl; 919 } 920 #endif 921 922 /* Attach all of the statically-linked malloc types. */ 923 __link_set_foreach(ksp, malloc_types) 924 malloc_type_attach(*ksp); 925 } 926 927 #ifdef DDB 928 #include <ddb/db_output.h> 929 930 /* 931 * Dump kmem statistics from ddb. 932 * 933 * usage: call dump_kmemstats 934 */ 935 void dump_kmemstats(void); 936 937 void 938 dump_kmemstats(void) 939 { 940 #ifdef KMEMSTATS 941 struct malloc_type *ksp; 942 943 for (ksp = kmemstatistics; ksp != NULL; ksp = ksp->ks_next) { 944 if (ksp->ks_memuse == 0) 945 continue; 946 db_printf("%s%.*s %ld\n", ksp->ks_shortdesc, 947 (int)(20 - strlen(ksp->ks_shortdesc)), 948 " ", 949 ksp->ks_memuse); 950 } 951 #else 952 db_printf("Kmem stats are not being collected.\n"); 953 #endif /* KMEMSTATS */ 954 } 955 #endif /* DDB */ 956 957 958 #if 0 959 /* 960 * Diagnostic messages about "Data modified on 961 * freelist" indicate a memory corruption, but 962 * they do not help tracking it down. 963 * This function can be called at various places 964 * to sanity check malloc's freelist and discover 965 * where does the corruption take place. 966 */ 967 int 968 freelist_sanitycheck(void) { 969 int i,j; 970 struct kmembuckets *kbp; 971 struct freelist *freep; 972 int rv = 0; 973 974 for (i = MINBUCKET; i <= MINBUCKET + 15; i++) { 975 kbp = &kmembuckets[i]; 976 freep = (struct freelist *)kbp->kb_next; 977 j = 0; 978 while(freep) { 979 vm_map_lock(kmem_map); 980 rv = uvm_map_checkprot(kmem_map, (vaddr_t)freep, 981 (vaddr_t)freep + sizeof(struct freelist), 982 VM_PROT_WRITE); 983 vm_map_unlock(kmem_map); 984 985 if ((rv == 0) || (*(int *)freep != WEIRD_ADDR)) { 986 printf("bucket %i, chunck %d at %p modified\n", 987 i, j, freep); 988 return 1; 989 } 990 freep = (struct freelist *)freep->next; 991 j++; 992 } 993 } 994 995 return 0; 996 } 997 #endif 998