1 /* $OpenBSD: kern_malloc.c,v 1.18 1999/11/25 13:41:30 art 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/map.h> 42 #include <sys/kernel.h> 43 #include <sys/malloc.h> 44 #include <sys/systm.h> 45 46 #include <vm/vm.h> 47 #include <vm/vm_kern.h> 48 49 #if defined(UVM) 50 #include <uvm/uvm_extern.h> 51 52 static struct vm_map kmem_map_store; 53 vm_map_t kmem_map = NULL; 54 #endif 55 56 struct kmembuckets bucket[MINBUCKET + 16]; 57 struct kmemstats kmemstats[M_LAST]; 58 struct kmemusage *kmemusage; 59 char *kmembase, *kmemlimit; 60 #if defined(KMEMSTATS) || defined(DIAGNOSTIC) || defined(FFS_SOFTUPDATES) 61 char *memname[] = INITKMEMNAMES; 62 #endif 63 64 #ifdef DIAGNOSTIC 65 /* 66 * This structure provides a set of masks to catch unaligned frees. 67 */ 68 long addrmask[] = { 0, 69 0x00000001, 0x00000003, 0x00000007, 0x0000000f, 70 0x0000001f, 0x0000003f, 0x0000007f, 0x000000ff, 71 0x000001ff, 0x000003ff, 0x000007ff, 0x00000fff, 72 0x00001fff, 0x00003fff, 0x00007fff, 0x0000ffff, 73 }; 74 75 /* 76 * The WEIRD_ADDR is used as known text to copy into free objects so 77 * that modifications after frees can be detected. 78 */ 79 #define WEIRD_ADDR ((unsigned) 0xdeadbeef) 80 #define MAX_COPY 32 81 82 /* 83 * Normally the freelist structure is used only to hold the list pointer 84 * for free objects. However, when running with diagnostics, the first 85 * 8 bytes of the structure is unused except for diagnostic information, 86 * and the free list pointer is at offst 8 in the structure. Since the 87 * first 8 bytes is the portion of the structure most often modified, this 88 * helps to detect memory reuse problems and avoid free list corruption. 89 */ 90 struct freelist { 91 int32_t spare0; 92 int16_t type; 93 int16_t spare1; 94 caddr_t next; 95 }; 96 #else /* !DIAGNOSTIC */ 97 struct freelist { 98 caddr_t next; 99 }; 100 #endif /* DIAGNOSTIC */ 101 102 /* 103 * Allocate a block of memory 104 */ 105 void * 106 malloc(size, type, flags) 107 unsigned long size; 108 int type, flags; 109 { 110 register struct kmembuckets *kbp; 111 register struct kmemusage *kup; 112 register struct freelist *freep; 113 long indx, npg, allocsize; 114 int s; 115 caddr_t va, cp, savedlist; 116 #ifdef DIAGNOSTIC 117 int32_t *end, *lp; 118 int copysize; 119 char *savedtype; 120 #endif 121 #ifdef KMEMSTATS 122 register struct kmemstats *ksp = &kmemstats[type]; 123 124 if (((unsigned long)type) > M_LAST) 125 panic("malloc - bogus type"); 126 #endif 127 indx = BUCKETINDX(size); 128 kbp = &bucket[indx]; 129 s = splimp(); 130 #ifdef KMEMSTATS 131 while (ksp->ks_memuse >= ksp->ks_limit) { 132 if (flags & M_NOWAIT) { 133 splx(s); 134 return ((void *) NULL); 135 } 136 if (ksp->ks_limblocks < 65535) 137 ksp->ks_limblocks++; 138 tsleep((caddr_t)ksp, PSWP+2, memname[type], 0); 139 } 140 ksp->ks_size |= 1 << indx; 141 #endif 142 #ifdef DIAGNOSTIC 143 copysize = 1 << indx < MAX_COPY ? 1 << indx : MAX_COPY; 144 #endif 145 if (kbp->kb_next == NULL) { 146 kbp->kb_last = NULL; 147 if (size > MAXALLOCSAVE) 148 allocsize = clrnd(round_page(size)); 149 else 150 allocsize = 1 << indx; 151 npg = clrnd(btoc(allocsize)); 152 #if defined(UVM) 153 va = (caddr_t) uvm_km_kmemalloc(kmem_map, uvmexp.kmem_object, 154 (vsize_t)ctob(npg), 155 (flags & M_NOWAIT) ? UVM_KMF_NOWAIT : 0); 156 #else 157 va = (caddr_t) kmem_malloc(kmem_map, (vsize_t)ctob(npg), 158 !(flags & M_NOWAIT)); 159 #endif 160 if (va == NULL) { 161 /* 162 * Kmem_malloc() can return NULL, even if it can 163 * wait, if there is no map space available, because 164 * it can't fix that problem. Neither can we, 165 * right now. (We should release pages which 166 * are completely free and which are in buckets 167 * with too many free elements.) 168 */ 169 if ((flags & M_NOWAIT) == 0) 170 panic("malloc: out of space in kmem_map"); 171 splx(s); 172 return ((void *) NULL); 173 } 174 #ifdef KMEMSTATS 175 kbp->kb_total += kbp->kb_elmpercl; 176 #endif 177 kup = btokup(va); 178 kup->ku_indx = indx; 179 if (allocsize > MAXALLOCSAVE) { 180 if (npg > 65535) 181 panic("malloc: allocation too large"); 182 kup->ku_pagecnt = npg; 183 #ifdef KMEMSTATS 184 ksp->ks_memuse += allocsize; 185 #endif 186 goto out; 187 } 188 #ifdef KMEMSTATS 189 kup->ku_freecnt = kbp->kb_elmpercl; 190 kbp->kb_totalfree += kbp->kb_elmpercl; 191 #endif 192 /* 193 * Just in case we blocked while allocating memory, 194 * and someone else also allocated memory for this 195 * bucket, don't assume the list is still empty. 196 */ 197 savedlist = kbp->kb_next; 198 kbp->kb_next = cp = va + (npg * PAGE_SIZE) - allocsize; 199 for (;;) { 200 freep = (struct freelist *)cp; 201 #ifdef DIAGNOSTIC 202 /* 203 * Copy in known text to detect modification 204 * after freeing. 205 */ 206 end = (int32_t *)&cp[copysize]; 207 for (lp = (int32_t *)cp; lp < end; lp++) 208 *lp = WEIRD_ADDR; 209 freep->type = M_FREE; 210 #endif /* DIAGNOSTIC */ 211 if (cp <= va) 212 break; 213 cp -= allocsize; 214 freep->next = cp; 215 } 216 freep->next = savedlist; 217 if (kbp->kb_last == NULL) 218 kbp->kb_last = (caddr_t)freep; 219 } 220 va = kbp->kb_next; 221 kbp->kb_next = ((struct freelist *)va)->next; 222 #ifdef DIAGNOSTIC 223 freep = (struct freelist *)va; 224 savedtype = (unsigned)freep->type < M_LAST ? 225 memname[freep->type] : "???"; 226 #if defined(UVM) 227 if (kbp->kb_next) { 228 int rv; 229 vaddr_t addr = (vaddr_t)kbp->kb_next; 230 231 vm_map_lock_read(kmem_map); 232 rv = uvm_map_checkprot(kmem_map, addr, 233 addr + sizeof(struct freelist), 234 VM_PROT_WRITE); 235 vm_map_unlock_read(kmem_map); 236 237 if (!rv) 238 #else 239 if (kbp->kb_next && 240 !kernacc(kbp->kb_next, sizeof(struct freelist), 0)) 241 #endif 242 { 243 printf("%s %d of object %p size %ld %s %s (invalid addr %p)\n", 244 "Data modified on freelist: word", 245 (int32_t *)&kbp->kb_next - (int32_t *)kbp, va, size, 246 "previous type", savedtype, kbp->kb_next); 247 kbp->kb_next = NULL; 248 #if defined(UVM) 249 } 250 #endif 251 } 252 253 /* Fill the fields that we've used with WEIRD_ADDR */ 254 #if BYTE_ORDER == BIG_ENDIAN 255 freep->type = WEIRD_ADDR >> 16; 256 #endif 257 #if BYTE_ORDER == LITTLE_ENDIAN 258 freep->type = (short)WEIRD_ADDR; 259 #endif 260 end = (int32_t *)&freep->next + 261 (sizeof(freep->next) / sizeof(int32_t)); 262 for (lp = (int32_t *)&freep->next; lp < end; lp++) 263 *lp = WEIRD_ADDR; 264 265 /* and check that the data hasn't been modified. */ 266 end = (int32_t *)&va[copysize]; 267 for (lp = (int32_t *)va; lp < end; lp++) { 268 if (*lp == WEIRD_ADDR) 269 continue; 270 printf("%s %d of object %p size %ld %s %s (0x%x != 0x%x)\n", 271 "Data modified on freelist: word", lp - (int32_t *)va, 272 va, size, "previous type", savedtype, *lp, WEIRD_ADDR); 273 break; 274 } 275 276 freep->spare0 = 0; 277 #endif /* DIAGNOSTIC */ 278 #ifdef KMEMSTATS 279 kup = btokup(va); 280 if (kup->ku_indx != indx) 281 panic("malloc: wrong bucket"); 282 if (kup->ku_freecnt == 0) 283 panic("malloc: lost data"); 284 kup->ku_freecnt--; 285 kbp->kb_totalfree--; 286 ksp->ks_memuse += 1 << indx; 287 out: 288 kbp->kb_calls++; 289 ksp->ks_inuse++; 290 ksp->ks_calls++; 291 if (ksp->ks_memuse > ksp->ks_maxused) 292 ksp->ks_maxused = ksp->ks_memuse; 293 #else 294 out: 295 #endif 296 splx(s); 297 return ((void *) va); 298 } 299 300 /* 301 * Free a block of memory allocated by malloc. 302 */ 303 void 304 free(addr, type) 305 void *addr; 306 int type; 307 { 308 register struct kmembuckets *kbp; 309 register struct kmemusage *kup; 310 register struct freelist *freep; 311 long size; 312 int s; 313 #ifdef DIAGNOSTIC 314 caddr_t cp; 315 int32_t *end, *lp; 316 long alloc, copysize; 317 #endif 318 #ifdef KMEMSTATS 319 register struct kmemstats *ksp = &kmemstats[type]; 320 #endif 321 322 kup = btokup(addr); 323 size = 1 << kup->ku_indx; 324 kbp = &bucket[kup->ku_indx]; 325 s = splimp(); 326 #ifdef DIAGNOSTIC 327 /* 328 * Check for returns of data that do not point to the 329 * beginning of the allocation. 330 */ 331 if (size > PAGE_SIZE * CLSIZE) 332 alloc = addrmask[BUCKETINDX(PAGE_SIZE * CLSIZE)]; 333 else 334 alloc = addrmask[kup->ku_indx]; 335 if (((u_long)addr & alloc) != 0) 336 panic("free: unaligned addr %p, size %ld, type %s, mask %ld", 337 addr, size, memname[type], alloc); 338 #endif /* DIAGNOSTIC */ 339 if (size > MAXALLOCSAVE) { 340 #if defined(UVM) 341 uvm_km_free(kmem_map, (vaddr_t)addr, ctob(kup->ku_pagecnt)); 342 #else 343 kmem_free(kmem_map, (vaddr_t)addr, ctob(kup->ku_pagecnt)); 344 #endif 345 #ifdef KMEMSTATS 346 size = kup->ku_pagecnt << PGSHIFT; 347 ksp->ks_memuse -= size; 348 kup->ku_indx = 0; 349 kup->ku_pagecnt = 0; 350 if (ksp->ks_memuse + size >= ksp->ks_limit && 351 ksp->ks_memuse < ksp->ks_limit) 352 wakeup((caddr_t)ksp); 353 ksp->ks_inuse--; 354 kbp->kb_total -= 1; 355 #endif 356 splx(s); 357 return; 358 } 359 freep = (struct freelist *)addr; 360 #ifdef DIAGNOSTIC 361 /* 362 * Check for multiple frees. Use a quick check to see if 363 * it looks free before laboriously searching the freelist. 364 */ 365 if (freep->spare0 == WEIRD_ADDR) { 366 for (cp = kbp->kb_next; cp; 367 cp = ((struct freelist *)cp)->next) { 368 if (addr != cp) 369 continue; 370 printf("multiply freed item %p\n", addr); 371 panic("free: duplicated free"); 372 } 373 } 374 /* 375 * Copy in known text to detect modification after freeing 376 * and to make it look free. Also, save the type being freed 377 * so we can list likely culprit if modification is detected 378 * when the object is reallocated. 379 */ 380 copysize = size < MAX_COPY ? size : MAX_COPY; 381 end = (int32_t *)&((caddr_t)addr)[copysize]; 382 for (lp = (int32_t *)addr; lp < end; lp++) 383 *lp = WEIRD_ADDR; 384 freep->type = type; 385 #endif /* DIAGNOSTIC */ 386 #ifdef KMEMSTATS 387 kup->ku_freecnt++; 388 if (kup->ku_freecnt >= kbp->kb_elmpercl) { 389 if (kup->ku_freecnt > kbp->kb_elmpercl) 390 panic("free: multiple frees"); 391 else if (kbp->kb_totalfree > kbp->kb_highwat) 392 kbp->kb_couldfree++; 393 } 394 kbp->kb_totalfree++; 395 ksp->ks_memuse -= size; 396 if (ksp->ks_memuse + size >= ksp->ks_limit && 397 ksp->ks_memuse < ksp->ks_limit) 398 wakeup((caddr_t)ksp); 399 ksp->ks_inuse--; 400 #endif 401 if (kbp->kb_next == NULL) 402 kbp->kb_next = addr; 403 else 404 ((struct freelist *)kbp->kb_last)->next = addr; 405 freep->next = NULL; 406 kbp->kb_last = addr; 407 splx(s); 408 } 409 410 /* 411 * Initialize the kernel memory allocator 412 */ 413 void 414 kmeminit() 415 { 416 #ifdef KMEMSTATS 417 register long indx; 418 #endif 419 int npg; 420 421 #if ((MAXALLOCSAVE & (MAXALLOCSAVE - 1)) != 0) 422 ERROR!_kmeminit:_MAXALLOCSAVE_not_power_of_2 423 #endif 424 #if (MAXALLOCSAVE > MINALLOCSIZE * 32768) 425 ERROR!_kmeminit:_MAXALLOCSAVE_too_big 426 #endif 427 #if (MAXALLOCSAVE < CLBYTES) 428 ERROR!_kmeminit:_MAXALLOCSAVE_too_small 429 #endif 430 431 #ifdef DIAGNOSTIC 432 if (sizeof(struct freelist) > (1 << MINBUCKET)) 433 panic("kmeminit: minbucket too small/struct freelist too big"); 434 #endif 435 436 npg = VM_KMEM_SIZE / PAGE_SIZE; 437 #if defined(UVM) 438 kmemusage = (struct kmemusage *) uvm_km_zalloc(kernel_map, 439 (vsize_t)(npg * sizeof(struct kmemusage))); 440 kmem_map = uvm_km_suballoc(kernel_map, (vaddr_t *)&kmembase, 441 (vaddr_t *)&kmemlimit, (vsize_t)(npg * PAGE_SIZE), 442 FALSE, FALSE, &kmem_map_store); 443 #else 444 kmemusage = (struct kmemusage *) kmem_alloc(kernel_map, 445 (vsize_t)(npg * sizeof(struct kmemusage))); 446 kmem_map = kmem_suballoc(kernel_map, (vaddr_t *)&kmembase, 447 (vaddr_t *)&kmemlimit, (vsize_t)(npg * PAGE_SIZE), FALSE); 448 #endif 449 #ifdef KMEMSTATS 450 for (indx = 0; indx < MINBUCKET + 16; indx++) { 451 if (1 << indx >= CLBYTES) 452 bucket[indx].kb_elmpercl = 1; 453 else 454 bucket[indx].kb_elmpercl = CLBYTES / (1 << indx); 455 bucket[indx].kb_highwat = 5 * bucket[indx].kb_elmpercl; 456 } 457 for (indx = 0; indx < M_LAST; indx++) 458 kmemstats[indx].ks_limit = npg * PAGE_SIZE * 6 / 10; 459 #endif 460 } 461