kern_malloc.c revision 1.12
1 /* $NetBSD: kern_malloc.c,v 1.12 1996/02/04 02:15:48 christos 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. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)kern_malloc.c 8.3 (Berkeley) 1/4/94 36 */ 37 38 #include <sys/param.h> 39 #include <sys/proc.h> 40 #include <sys/map.h> 41 #include <sys/kernel.h> 42 #include <sys/malloc.h> 43 #include <sys/systm.h> 44 45 #include <vm/vm.h> 46 #include <vm/vm_kern.h> 47 48 #include <kern/kern_extern.h> 49 50 struct kmembuckets bucket[MINBUCKET + 16]; 51 struct kmemstats kmemstats[M_LAST]; 52 struct kmemusage *kmemusage; 53 char *kmembase, *kmemlimit; 54 char *memname[] = INITKMEMNAMES; 55 56 #ifdef DIAGNOSTIC 57 /* 58 * This structure provides a set of masks to catch unaligned frees. 59 */ 60 long addrmask[] = { 0, 61 0x00000001, 0x00000003, 0x00000007, 0x0000000f, 62 0x0000001f, 0x0000003f, 0x0000007f, 0x000000ff, 63 0x000001ff, 0x000003ff, 0x000007ff, 0x00000fff, 64 0x00001fff, 0x00003fff, 0x00007fff, 0x0000ffff, 65 }; 66 67 /* 68 * The WEIRD_ADDR is used as known text to copy into free objects so 69 * that modifications after frees can be detected. 70 */ 71 #define WEIRD_ADDR ((unsigned) 0xdeadbeef) 72 #define MAX_COPY 32 73 74 /* 75 * Normally the freelist structure is used only to hold the list pointer 76 * for free objects. However, when running with diagnostics, the first 77 * 8 bytes of the structure is unused except for diagnostic information, 78 * and the free list pointer is at offst 8 in the structure. Since the 79 * first 8 bytes is the portion of the structure most often modified, this 80 * helps to detect memory reuse problems and avoid free list corruption. 81 */ 82 struct freelist { 83 int32_t spare0; 84 int16_t type; 85 int16_t spare1; 86 caddr_t next; 87 }; 88 #else /* !DIAGNOSTIC */ 89 struct freelist { 90 caddr_t next; 91 }; 92 #endif /* DIAGNOSTIC */ 93 94 /* 95 * Allocate a block of memory 96 */ 97 void * 98 malloc(size, type, flags) 99 unsigned long size; 100 int type, flags; 101 { 102 register struct kmembuckets *kbp; 103 register struct kmemusage *kup; 104 register struct freelist *freep; 105 long indx, npg, allocsize; 106 int s; 107 caddr_t va, cp, savedlist; 108 #ifdef DIAGNOSTIC 109 int32_t *end, *lp; 110 int copysize; 111 char *savedtype; 112 #endif 113 #ifdef KMEMSTATS 114 register struct kmemstats *ksp = &kmemstats[type]; 115 116 if (((unsigned long)type) > M_LAST) 117 panic("malloc - bogus type"); 118 #endif 119 indx = BUCKETINDX(size); 120 kbp = &bucket[indx]; 121 s = splimp(); 122 #ifdef KMEMSTATS 123 while (ksp->ks_memuse >= ksp->ks_limit) { 124 if (flags & M_NOWAIT) { 125 splx(s); 126 return ((void *) NULL); 127 } 128 if (ksp->ks_limblocks < 65535) 129 ksp->ks_limblocks++; 130 tsleep((caddr_t)ksp, PSWP+2, memname[type], 0); 131 } 132 ksp->ks_size |= 1 << indx; 133 #endif 134 #ifdef DIAGNOSTIC 135 copysize = 1 << indx < MAX_COPY ? 1 << indx : MAX_COPY; 136 #endif 137 if (kbp->kb_next == NULL) { 138 kbp->kb_last = NULL; 139 if (size > MAXALLOCSAVE) 140 allocsize = roundup(size, CLBYTES); 141 else 142 allocsize = 1 << indx; 143 npg = clrnd(btoc(allocsize)); 144 va = (caddr_t) kmem_malloc(kmem_map, (vm_size_t)ctob(npg), 145 !(flags & M_NOWAIT)); 146 if (va == NULL) { 147 splx(s); 148 return ((void *) NULL); 149 } 150 #ifdef KMEMSTATS 151 kbp->kb_total += kbp->kb_elmpercl; 152 #endif 153 kup = btokup(va); 154 kup->ku_indx = indx; 155 if (allocsize > MAXALLOCSAVE) { 156 if (npg > 65535) 157 panic("malloc: allocation too large"); 158 kup->ku_pagecnt = npg; 159 #ifdef KMEMSTATS 160 ksp->ks_memuse += allocsize; 161 #endif 162 goto out; 163 } 164 #ifdef KMEMSTATS 165 kup->ku_freecnt = kbp->kb_elmpercl; 166 kbp->kb_totalfree += kbp->kb_elmpercl; 167 #endif 168 /* 169 * Just in case we blocked while allocating memory, 170 * and someone else also allocated memory for this 171 * bucket, don't assume the list is still empty. 172 */ 173 savedlist = kbp->kb_next; 174 kbp->kb_next = cp = va + (npg * NBPG) - allocsize; 175 for (;;) { 176 freep = (struct freelist *)cp; 177 #ifdef DIAGNOSTIC 178 /* 179 * Copy in known text to detect modification 180 * after freeing. 181 */ 182 end = (int32_t *)&cp[copysize]; 183 for (lp = (int32_t *)cp; lp < end; lp++) 184 *lp = WEIRD_ADDR; 185 freep->type = M_FREE; 186 #endif /* DIAGNOSTIC */ 187 if (cp <= va) 188 break; 189 cp -= allocsize; 190 freep->next = cp; 191 } 192 freep->next = savedlist; 193 if (kbp->kb_last == NULL) 194 kbp->kb_last = (caddr_t)freep; 195 } 196 va = kbp->kb_next; 197 kbp->kb_next = ((struct freelist *)va)->next; 198 #ifdef DIAGNOSTIC 199 freep = (struct freelist *)va; 200 savedtype = (unsigned)freep->type < M_LAST ? 201 memname[freep->type] : "???"; 202 if (kbp->kb_next && 203 !kernacc(kbp->kb_next, sizeof(struct freelist), 0)) { 204 printf("%s %d of object %p size %d %s %s (invalid addr %p)\n", 205 "Data modified on freelist: word", 206 (int32_t *)&kbp->kb_next - (int32_t *)kbp, va, size, 207 "previous type", savedtype, kbp->kb_next); 208 kbp->kb_next = NULL; 209 } 210 211 /* Fill the fields that we've used with WEIRD_ADDR */ 212 #if BYTE_ORDER == BIG_ENDIAN 213 freep->type = WEIRD_ADDR >> 16; 214 #endif 215 #if BYTE_ORDER == LITTLE_ENDIAN 216 freep->type = (short)WEIRD_ADDR; 217 #endif 218 end = (int32_t *)&freep->next + 219 (sizeof(freep->next) / sizeof(int32_t)); 220 for (lp = (int32_t *)&freep->next; lp < end; lp++) 221 *lp = WEIRD_ADDR; 222 223 /* and check that the data hasn't been modified. */ 224 end = (int32_t *)&va[copysize]; 225 for (lp = (int32_t *)va; lp < end; lp++) { 226 if (*lp == WEIRD_ADDR) 227 continue; 228 printf("%s %d of object %p size %d %s %s (%p != %p)\n", 229 "Data modified on freelist: word", lp - (int32_t *)va, 230 va, size, "previous type", savedtype, (void *)*lp, 231 (void *) WEIRD_ADDR); 232 break; 233 } 234 235 freep->spare0 = 0; 236 #endif /* DIAGNOSTIC */ 237 #ifdef KMEMSTATS 238 kup = btokup(va); 239 if (kup->ku_indx != indx) 240 panic("malloc: wrong bucket"); 241 if (kup->ku_freecnt == 0) 242 panic("malloc: lost data"); 243 kup->ku_freecnt--; 244 kbp->kb_totalfree--; 245 ksp->ks_memuse += 1 << indx; 246 out: 247 kbp->kb_calls++; 248 ksp->ks_inuse++; 249 ksp->ks_calls++; 250 if (ksp->ks_memuse > ksp->ks_maxused) 251 ksp->ks_maxused = ksp->ks_memuse; 252 #else 253 out: 254 #endif 255 splx(s); 256 return ((void *) va); 257 } 258 259 /* 260 * Free a block of memory allocated by malloc. 261 */ 262 void 263 free(addr, type) 264 void *addr; 265 int type; 266 { 267 register struct kmembuckets *kbp; 268 register struct kmemusage *kup; 269 register struct freelist *freep; 270 long size; 271 int s; 272 #ifdef DIAGNOSTIC 273 caddr_t cp; 274 int32_t *end, *lp; 275 long alloc, copysize; 276 #endif 277 #ifdef KMEMSTATS 278 register struct kmemstats *ksp = &kmemstats[type]; 279 #endif 280 281 kup = btokup(addr); 282 size = 1 << kup->ku_indx; 283 kbp = &bucket[kup->ku_indx]; 284 s = splimp(); 285 #ifdef DIAGNOSTIC 286 /* 287 * Check for returns of data that do not point to the 288 * beginning of the allocation. 289 */ 290 if (size > NBPG * CLSIZE) 291 alloc = addrmask[BUCKETINDX(NBPG * CLSIZE)]; 292 else 293 alloc = addrmask[kup->ku_indx]; 294 if (((u_long)addr & alloc) != 0) 295 panic("free: unaligned addr 0x%x, size %d, type %s, mask %d\n", 296 addr, size, memname[type], alloc); 297 #endif /* DIAGNOSTIC */ 298 if (size > MAXALLOCSAVE) { 299 kmem_free(kmem_map, (vm_offset_t)addr, ctob(kup->ku_pagecnt)); 300 #ifdef KMEMSTATS 301 size = kup->ku_pagecnt << PGSHIFT; 302 ksp->ks_memuse -= size; 303 kup->ku_indx = 0; 304 kup->ku_pagecnt = 0; 305 if (ksp->ks_memuse + size >= ksp->ks_limit && 306 ksp->ks_memuse < ksp->ks_limit) 307 wakeup((caddr_t)ksp); 308 ksp->ks_inuse--; 309 kbp->kb_total -= 1; 310 #endif 311 splx(s); 312 return; 313 } 314 freep = (struct freelist *)addr; 315 #ifdef DIAGNOSTIC 316 /* 317 * Check for multiple frees. Use a quick check to see if 318 * it looks free before laboriously searching the freelist. 319 */ 320 if (freep->spare0 == WEIRD_ADDR) { 321 for (cp = kbp->kb_next; cp; cp = *(caddr_t *)cp) { 322 if (addr != cp) 323 continue; 324 printf("multiply freed item %p\n", addr); 325 panic("free: duplicated free"); 326 } 327 } 328 /* 329 * Copy in known text to detect modification after freeing 330 * and to make it look free. Also, save the type being freed 331 * so we can list likely culprit if modification is detected 332 * when the object is reallocated. 333 */ 334 copysize = size < MAX_COPY ? size : MAX_COPY; 335 end = (int32_t *)&((caddr_t)addr)[copysize]; 336 for (lp = (int32_t *)addr; lp < end; lp++) 337 *lp = WEIRD_ADDR; 338 freep->type = type; 339 #endif /* DIAGNOSTIC */ 340 #ifdef KMEMSTATS 341 kup->ku_freecnt++; 342 if (kup->ku_freecnt >= kbp->kb_elmpercl) 343 if (kup->ku_freecnt > kbp->kb_elmpercl) 344 panic("free: multiple frees"); 345 else if (kbp->kb_totalfree > kbp->kb_highwat) 346 kbp->kb_couldfree++; 347 kbp->kb_totalfree++; 348 ksp->ks_memuse -= size; 349 if (ksp->ks_memuse + size >= ksp->ks_limit && 350 ksp->ks_memuse < ksp->ks_limit) 351 wakeup((caddr_t)ksp); 352 ksp->ks_inuse--; 353 #endif 354 if (kbp->kb_next == NULL) 355 kbp->kb_next = addr; 356 else 357 ((struct freelist *)kbp->kb_last)->next = addr; 358 freep->next = NULL; 359 kbp->kb_last = addr; 360 splx(s); 361 } 362 363 /* 364 * Initialize the kernel memory allocator 365 */ 366 void 367 kmeminit() 368 { 369 register long indx; 370 int npg; 371 372 #if ((MAXALLOCSAVE & (MAXALLOCSAVE - 1)) != 0) 373 ERROR!_kmeminit:_MAXALLOCSAVE_not_power_of_2 374 #endif 375 #if (MAXALLOCSAVE > MINALLOCSIZE * 32768) 376 ERROR!_kmeminit:_MAXALLOCSAVE_too_big 377 #endif 378 #if (MAXALLOCSAVE < CLBYTES) 379 ERROR!_kmeminit:_MAXALLOCSAVE_too_small 380 #endif 381 382 if (sizeof(struct freelist) > (1 << MINBUCKET)) 383 panic("minbucket too small/struct freelist too big"); 384 385 npg = VM_KMEM_SIZE/ NBPG; 386 kmemusage = (struct kmemusage *) kmem_alloc(kernel_map, 387 (vm_size_t)(npg * sizeof(struct kmemusage))); 388 kmem_map = kmem_suballoc(kernel_map, (vm_offset_t *)&kmembase, 389 (vm_offset_t *)&kmemlimit, (vm_size_t)(npg * NBPG), FALSE); 390 #ifdef KMEMSTATS 391 for (indx = 0; indx < MINBUCKET + 16; indx++) { 392 if (1 << indx >= CLBYTES) 393 bucket[indx].kb_elmpercl = 1; 394 else 395 bucket[indx].kb_elmpercl = CLBYTES / (1 << indx); 396 bucket[indx].kb_highwat = 5 * bucket[indx].kb_elmpercl; 397 } 398 for (indx = 0; indx < M_LAST; indx++) 399 kmemstats[indx].ks_limit = npg * NBPG * 6 / 10; 400 #endif 401 } 402
Indexes created Mon Sep 22 13:09:51 GMT 2025