1 /* $OpenBSD: kern_malloc.c,v 1.47 2002/02/12 17:19:41 provos Exp $ */ 2 /* $NetBSD: kern_malloc.c,v 1.15.4.2 1996/06/13 17:10:56 cgd Exp $ */ 3 4 /* 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 8.3 (Berkeley) 1/4/94 37 */ 38 39 #include <sys/param.h> 40 #include <sys/proc.h> 41 #include <sys/kernel.h> 42 #include <sys/malloc.h> 43 #include <sys/systm.h> 44 #include <sys/sysctl.h> 45 46 #include <uvm/uvm_extern.h> 47 48 static struct vm_map_intrsafe kmem_map_store; 49 struct vm_map *kmem_map = NULL; 50 51 #ifdef NKMEMCLUSTERS 52 #error NKMEMCLUSTERS is obsolete; remove it from your kernel config file and use NKMEMPAGES instead or let the kernel auto-size 53 #endif 54 55 /* 56 * Default number of pages in kmem_map. We attempt to calculate this 57 * at run-time, but allow it to be either patched or set in the kernel 58 * config file. 59 */ 60 #ifndef NKMEMPAGES 61 #define NKMEMPAGES 0 62 #endif 63 int nkmempages = NKMEMPAGES; 64 65 /* 66 * Defaults for lower- and upper-bounds for the kmem_map page count. 67 * Can be overridden by kernel config options. 68 */ 69 #ifndef NKMEMPAGES_MIN 70 #define NKMEMPAGES_MIN NKMEMPAGES_MIN_DEFAULT 71 #endif 72 73 #ifndef NKMEMPAGES_MAX 74 #define NKMEMPAGES_MAX NKMEMPAGES_MAX_DEFAULT 75 #endif 76 77 struct kmembuckets bucket[MINBUCKET + 16]; 78 struct kmemstats kmemstats[M_LAST]; 79 struct kmemusage *kmemusage; 80 char *kmembase, *kmemlimit; 81 char buckstring[16 * sizeof("123456,")]; 82 int buckstring_init = 0; 83 #if defined(KMEMSTATS) || defined(DIAGNOSTIC) || defined(FFS_SOFTUPDATES) 84 char *memname[] = INITKMEMNAMES; 85 char *memall = NULL; 86 extern struct lock sysctl_kmemlock; 87 #endif 88 89 #ifdef DIAGNOSTIC 90 /* 91 * This structure provides a set of masks to catch unaligned frees. 92 */ 93 long addrmask[] = { 0, 94 0x00000001, 0x00000003, 0x00000007, 0x0000000f, 95 0x0000001f, 0x0000003f, 0x0000007f, 0x000000ff, 96 0x000001ff, 0x000003ff, 0x000007ff, 0x00000fff, 97 0x00001fff, 0x00003fff, 0x00007fff, 0x0000ffff, 98 }; 99 100 /* 101 * The WEIRD_ADDR is used as known text to copy into free objects so 102 * that modifications after frees can be detected. 103 */ 104 #define WEIRD_ADDR ((unsigned) 0xdeadbeef) 105 #define MAX_COPY 32 106 107 /* 108 * Normally the freelist structure is used only to hold the list pointer 109 * for free objects. However, when running with diagnostics, the first 110 * 8 bytes of the structure is unused except for diagnostic information, 111 * and the free list pointer is at offset 8 in the structure. Since the 112 * first 8 bytes is the portion of the structure most often modified, this 113 * helps to detect memory reuse problems and avoid free list corruption. 114 */ 115 struct freelist { 116 int32_t spare0; 117 int16_t type; 118 int16_t spare1; 119 caddr_t next; 120 }; 121 #else /* !DIAGNOSTIC */ 122 struct freelist { 123 caddr_t next; 124 }; 125 #endif /* DIAGNOSTIC */ 126 127 /* 128 * Allocate a block of memory 129 */ 130 void * 131 malloc(size, type, flags) 132 unsigned long size; 133 int type, flags; 134 { 135 register struct kmembuckets *kbp; 136 register struct kmemusage *kup; 137 register struct freelist *freep; 138 long indx, npg, allocsize; 139 int s; 140 caddr_t va, cp, savedlist; 141 #ifdef DIAGNOSTIC 142 int32_t *end, *lp; 143 int copysize; 144 char *savedtype; 145 #endif 146 #ifdef KMEMSTATS 147 register struct kmemstats *ksp = &kmemstats[type]; 148 149 if (((unsigned long)type) > M_LAST) 150 panic("malloc - bogus type"); 151 #endif 152 153 #ifdef MALLOC_DEBUG 154 if (debug_malloc(size, type, flags, (void **)&va)) 155 return ((void *) va); 156 #endif 157 158 indx = BUCKETINDX(size); 159 kbp = &bucket[indx]; 160 s = splimp(); 161 #ifdef KMEMSTATS 162 while (ksp->ks_memuse >= ksp->ks_limit) { 163 if (flags & M_NOWAIT) { 164 splx(s); 165 return ((void *) NULL); 166 } 167 if (ksp->ks_limblocks < 65535) 168 ksp->ks_limblocks++; 169 tsleep((caddr_t)ksp, PSWP+2, memname[type], 0); 170 } 171 ksp->ks_size |= 1 << indx; 172 #endif 173 #ifdef DIAGNOSTIC 174 copysize = 1 << indx < MAX_COPY ? 1 << indx : MAX_COPY; 175 #endif 176 if (kbp->kb_next == NULL) { 177 kbp->kb_last = NULL; 178 if (size > MAXALLOCSAVE) 179 allocsize = round_page(size); 180 else 181 allocsize = 1 << indx; 182 npg = btoc(allocsize); 183 va = (caddr_t) uvm_km_kmemalloc(kmem_map, uvmexp.kmem_object, 184 (vsize_t)ctob(npg), 185 (flags & M_NOWAIT) ? UVM_KMF_NOWAIT : 0); 186 if (va == NULL) { 187 /* 188 * Kmem_malloc() can return NULL, even if it can 189 * wait, if there is no map space available, because 190 * it can't fix that problem. Neither can we, 191 * right now. (We should release pages which 192 * are completely free and which are in buckets 193 * with too many free elements.) 194 */ 195 if ((flags & M_NOWAIT) == 0) 196 panic("malloc: out of space in kmem_map"); 197 splx(s); 198 return ((void *) NULL); 199 } 200 #ifdef KMEMSTATS 201 kbp->kb_total += kbp->kb_elmpercl; 202 #endif 203 kup = btokup(va); 204 kup->ku_indx = indx; 205 if (allocsize > MAXALLOCSAVE) { 206 if (npg > 65535) 207 panic("malloc: allocation too large"); 208 kup->ku_pagecnt = npg; 209 #ifdef KMEMSTATS 210 ksp->ks_memuse += allocsize; 211 #endif 212 goto out; 213 } 214 #ifdef KMEMSTATS 215 kup->ku_freecnt = kbp->kb_elmpercl; 216 kbp->kb_totalfree += kbp->kb_elmpercl; 217 #endif 218 /* 219 * Just in case we blocked while allocating memory, 220 * and someone else also allocated memory for this 221 * bucket, don't assume the list is still empty. 222 */ 223 savedlist = kbp->kb_next; 224 kbp->kb_next = cp = va + (npg * PAGE_SIZE) - allocsize; 225 for (;;) { 226 freep = (struct freelist *)cp; 227 #ifdef DIAGNOSTIC 228 /* 229 * Copy in known text to detect modification 230 * after freeing. 231 */ 232 end = (int32_t *)&cp[copysize]; 233 for (lp = (int32_t *)cp; lp < end; lp++) 234 *lp = WEIRD_ADDR; 235 freep->type = M_FREE; 236 #endif /* DIAGNOSTIC */ 237 if (cp <= va) 238 break; 239 cp -= allocsize; 240 freep->next = cp; 241 } 242 freep->next = savedlist; 243 if (kbp->kb_last == NULL) 244 kbp->kb_last = (caddr_t)freep; 245 } 246 va = kbp->kb_next; 247 kbp->kb_next = ((struct freelist *)va)->next; 248 #ifdef DIAGNOSTIC 249 freep = (struct freelist *)va; 250 savedtype = (unsigned)freep->type < M_LAST ? 251 memname[freep->type] : "???"; 252 if (kbp->kb_next) { 253 int rv; 254 vaddr_t addr = (vaddr_t)kbp->kb_next; 255 256 vm_map_lock(kmem_map); 257 rv = uvm_map_checkprot(kmem_map, addr, 258 addr + sizeof(struct freelist), VM_PROT_WRITE); 259 vm_map_unlock(kmem_map); 260 261 if (!rv) { 262 printf("%s %d of object %p size 0x%lx %s %s (invalid addr %p)\n", 263 "Data modified on freelist: word", 264 (int32_t *)&kbp->kb_next - (int32_t *)kbp, va, size, 265 "previous type", savedtype, kbp->kb_next); 266 kbp->kb_next = NULL; 267 } 268 } 269 270 /* Fill the fields that we've used with WEIRD_ADDR */ 271 #if BYTE_ORDER == BIG_ENDIAN 272 freep->type = WEIRD_ADDR >> 16; 273 #endif 274 #if BYTE_ORDER == LITTLE_ENDIAN 275 freep->type = (short)WEIRD_ADDR; 276 #endif 277 end = (int32_t *)&freep->next + 278 (sizeof(freep->next) / sizeof(int32_t)); 279 for (lp = (int32_t *)&freep->next; lp < end; lp++) 280 *lp = WEIRD_ADDR; 281 282 /* and check that the data hasn't been modified. */ 283 end = (int32_t *)&va[copysize]; 284 for (lp = (int32_t *)va; lp < end; lp++) { 285 if (*lp == WEIRD_ADDR) 286 continue; 287 printf("%s %d of object %p size 0x%lx %s %s (0x%x != 0x%x)\n", 288 "Data modified on freelist: word", lp - (int32_t *)va, 289 va, size, "previous type", savedtype, *lp, WEIRD_ADDR); 290 break; 291 } 292 293 freep->spare0 = 0; 294 #endif /* DIAGNOSTIC */ 295 #ifdef KMEMSTATS 296 kup = btokup(va); 297 if (kup->ku_indx != indx) 298 panic("malloc: wrong bucket"); 299 if (kup->ku_freecnt == 0) 300 panic("malloc: lost data"); 301 kup->ku_freecnt--; 302 kbp->kb_totalfree--; 303 ksp->ks_memuse += 1 << indx; 304 out: 305 kbp->kb_calls++; 306 ksp->ks_inuse++; 307 ksp->ks_calls++; 308 if (ksp->ks_memuse > ksp->ks_maxused) 309 ksp->ks_maxused = ksp->ks_memuse; 310 #else 311 out: 312 #endif 313 splx(s); 314 return ((void *) va); 315 } 316 317 /* 318 * Free a block of memory allocated by malloc. 319 */ 320 void 321 free(addr, type) 322 void *addr; 323 int type; 324 { 325 register struct kmembuckets *kbp; 326 register struct kmemusage *kup; 327 register struct freelist *freep; 328 long size; 329 int s; 330 #ifdef DIAGNOSTIC 331 caddr_t cp; 332 int32_t *end, *lp; 333 long alloc, copysize; 334 #endif 335 #ifdef KMEMSTATS 336 register struct kmemstats *ksp = &kmemstats[type]; 337 #endif 338 339 #ifdef MALLOC_DEBUG 340 if (debug_free(addr, type)) 341 return; 342 #endif 343 344 #ifdef DIAGNOSTIC 345 if (addr < (void *)kmembase || addr >= (void *)kmemlimit) 346 panic("free: non-malloced addr %p type %s", addr, 347 memname[type]); 348 #endif 349 350 kup = btokup(addr); 351 size = 1 << kup->ku_indx; 352 kbp = &bucket[kup->ku_indx]; 353 s = splimp(); 354 #ifdef DIAGNOSTIC 355 /* 356 * Check for returns of data that do not point to the 357 * beginning of the allocation. 358 */ 359 if (size > PAGE_SIZE) 360 alloc = addrmask[BUCKETINDX(PAGE_SIZE)]; 361 else 362 alloc = addrmask[kup->ku_indx]; 363 if (((u_long)addr & alloc) != 0) 364 panic("free: unaligned addr %p, size %ld, type %s, mask %ld", 365 addr, size, memname[type], alloc); 366 #endif /* DIAGNOSTIC */ 367 if (size > MAXALLOCSAVE) { 368 uvm_km_free(kmem_map, (vaddr_t)addr, ctob(kup->ku_pagecnt)); 369 #ifdef KMEMSTATS 370 size = kup->ku_pagecnt << PGSHIFT; 371 ksp->ks_memuse -= size; 372 kup->ku_indx = 0; 373 kup->ku_pagecnt = 0; 374 if (ksp->ks_memuse + size >= ksp->ks_limit && 375 ksp->ks_memuse < ksp->ks_limit) 376 wakeup((caddr_t)ksp); 377 ksp->ks_inuse--; 378 kbp->kb_total -= 1; 379 #endif 380 splx(s); 381 return; 382 } 383 freep = (struct freelist *)addr; 384 #ifdef DIAGNOSTIC 385 /* 386 * Check for multiple frees. Use a quick check to see if 387 * it looks free before laboriously searching the freelist. 388 */ 389 if (freep->spare0 == WEIRD_ADDR) { 390 for (cp = kbp->kb_next; cp; 391 cp = ((struct freelist *)cp)->next) { 392 if (addr != cp) 393 continue; 394 printf("multiply freed item %p\n", addr); 395 panic("free: duplicated free"); 396 } 397 } 398 /* 399 * Copy in known text to detect modification after freeing 400 * and to make it look free. Also, save the type being freed 401 * so we can list likely culprit if modification is detected 402 * when the object is reallocated. 403 */ 404 copysize = size < MAX_COPY ? size : MAX_COPY; 405 end = (int32_t *)&((caddr_t)addr)[copysize]; 406 for (lp = (int32_t *)addr; lp < end; lp++) 407 *lp = WEIRD_ADDR; 408 freep->type = type; 409 #endif /* DIAGNOSTIC */ 410 #ifdef KMEMSTATS 411 kup->ku_freecnt++; 412 if (kup->ku_freecnt >= kbp->kb_elmpercl) { 413 if (kup->ku_freecnt > kbp->kb_elmpercl) 414 panic("free: multiple frees"); 415 else if (kbp->kb_totalfree > kbp->kb_highwat) 416 kbp->kb_couldfree++; 417 } 418 kbp->kb_totalfree++; 419 ksp->ks_memuse -= size; 420 if (ksp->ks_memuse + size >= ksp->ks_limit && 421 ksp->ks_memuse < ksp->ks_limit) 422 wakeup((caddr_t)ksp); 423 ksp->ks_inuse--; 424 #endif 425 if (kbp->kb_next == NULL) 426 kbp->kb_next = addr; 427 else 428 ((struct freelist *)kbp->kb_last)->next = addr; 429 freep->next = NULL; 430 kbp->kb_last = addr; 431 splx(s); 432 } 433 434 /* 435 * Compute the number of pages that kmem_map will map, that is, 436 * the size of the kernel malloc arena. 437 */ 438 void 439 kmeminit_nkmempages() 440 { 441 int npages; 442 443 if (nkmempages != 0) { 444 /* 445 * It's already been set (by us being here before, or 446 * by patching or kernel config options), bail out now. 447 */ 448 return; 449 } 450 451 /* 452 * We use the following (simple) formula: 453 * 454 * - Starting point is physical memory / 4. 455 * 456 * - Clamp it down to NKMEMPAGES_MAX. 457 * 458 * - Round it up to NKMEMPAGES_MIN. 459 */ 460 npages = physmem / 4; 461 462 if (npages > NKMEMPAGES_MAX) 463 npages = NKMEMPAGES_MAX; 464 465 if (npages < NKMEMPAGES_MIN) 466 npages = NKMEMPAGES_MIN; 467 468 nkmempages = npages; 469 } 470 471 /* 472 * Initialize the kernel memory allocator 473 */ 474 void 475 kmeminit() 476 { 477 #ifdef KMEMSTATS 478 long indx; 479 #endif 480 481 #ifdef DIAGNOSTIC 482 if (sizeof(struct freelist) > (1 << MINBUCKET)) 483 panic("kmeminit: minbucket too small/struct freelist too big"); 484 #endif 485 486 /* 487 * Compute the number of kmem_map pages, if we have not 488 * done so already. 489 */ 490 kmeminit_nkmempages(); 491 492 kmem_map = uvm_km_suballoc(kernel_map, (vaddr_t *)&kmembase, 493 (vaddr_t *)&kmemlimit, (vsize_t)(nkmempages * PAGE_SIZE), 494 VM_MAP_INTRSAFE, FALSE, &kmem_map_store.vmi_map); 495 kmemusage = (struct kmemusage *) uvm_km_zalloc(kernel_map, 496 (vsize_t)(nkmempages * sizeof(struct kmemusage))); 497 #ifdef KMEMSTATS 498 for (indx = 0; indx < MINBUCKET + 16; indx++) { 499 if (1 << indx >= PAGE_SIZE) 500 bucket[indx].kb_elmpercl = 1; 501 else 502 bucket[indx].kb_elmpercl = PAGE_SIZE / (1 << indx); 503 bucket[indx].kb_highwat = 5 * bucket[indx].kb_elmpercl; 504 } 505 for (indx = 0; indx < M_LAST; indx++) 506 kmemstats[indx].ks_limit = nkmempages * PAGE_SIZE * 6 / 10; 507 #endif 508 #ifdef MALLOC_DEBUG 509 debug_malloc_init(); 510 #endif 511 } 512 513 /* 514 * Return kernel malloc statistics information. 515 */ 516 int 517 sysctl_malloc(name, namelen, oldp, oldlenp, newp, newlen, p) 518 int *name; 519 u_int namelen; 520 void *oldp; 521 size_t *oldlenp; 522 void *newp; 523 size_t newlen; 524 struct proc *p; 525 { 526 struct kmembuckets kb; 527 int i, siz; 528 529 if (namelen != 2 && name[0] != KERN_MALLOC_BUCKETS && 530 name[0] != KERN_MALLOC_KMEMNAMES) 531 return (ENOTDIR); /* overloaded */ 532 533 switch (name[0]) { 534 case KERN_MALLOC_BUCKETS: 535 /* Initialize the first time */ 536 if (buckstring_init == 0) { 537 buckstring_init = 1; 538 bzero(buckstring, sizeof(buckstring)); 539 for (siz = 0, i = MINBUCKET; i < MINBUCKET + 16; i++) 540 siz += sprintf(buckstring + siz, 541 "%d,", (u_int)(1<<i)); 542 /* Remove trailing comma */ 543 if (siz) 544 buckstring[siz - 1] = '\0'; 545 } 546 return (sysctl_rdstring(oldp, oldlenp, newp, buckstring)); 547 548 case KERN_MALLOC_BUCKET: 549 bcopy(&bucket[BUCKETINDX(name[1])], &kb, sizeof(kb)); 550 kb.kb_next = kb.kb_last = 0; 551 return (sysctl_rdstruct(oldp, oldlenp, newp, &kb, sizeof(kb))); 552 case KERN_MALLOC_KMEMSTATS: 553 #ifdef KMEMSTATS 554 if ((name[1] < 0) || (name[1] >= M_LAST)) 555 return (EINVAL); 556 return (sysctl_rdstruct(oldp, oldlenp, newp, 557 &kmemstats[name[1]], sizeof(struct kmemstats))); 558 #else 559 return (EOPNOTSUPP); 560 #endif 561 case KERN_MALLOC_KMEMNAMES: 562 #if defined(KMEMSTATS) || defined(DIAGNOSTIC) || defined(FFS_SOFTUPDATES) 563 if (memall == NULL) { 564 int totlen; 565 566 i = lockmgr(&sysctl_kmemlock, LK_EXCLUSIVE, NULL, p); 567 if (i) 568 return (i); 569 570 /* Figure out how large a buffer we need */ 571 for (totlen = 0, i = 0; i < M_LAST; i++) { 572 if (memname[i]) 573 totlen += strlen(memname[i]); 574 totlen++; 575 } 576 memall = malloc(totlen + M_LAST, M_SYSCTL, M_WAITOK); 577 bzero(memall, totlen + M_LAST); 578 for (siz = 0, i = 0; i < M_LAST; i++) 579 siz += sprintf(memall + siz, "%s,", 580 memname[i] ? memname[i] : ""); 581 582 /* Remove trailing comma */ 583 if (siz) 584 memall[siz - 1] = '\0'; 585 586 /* Now, convert all spaces to underscores */ 587 for (i = 0; i < totlen; i++) 588 if (memall[i] == ' ') 589 memall[i] = '_'; 590 lockmgr(&sysctl_kmemlock, LK_RELEASE, NULL, p); 591 } 592 return (sysctl_rdstring(oldp, oldlenp, newp, memall)); 593 #else 594 return (EOPNOTSUPP); 595 #endif 596 default: 597 return (EOPNOTSUPP); 598 } 599 /* NOTREACHED */ 600 } 601 602 /* 603 * Round up a size to how much malloc would actually allocate. 604 */ 605 size_t 606 malloc_roundup(size_t sz) 607 { 608 if (sz > MAXALLOCSAVE) 609 return round_page(sz); 610 611 return (1 << BUCKETINDX(sz)); 612 } 613