kern_malloc.c revision 1.13
1 /* $NetBSD: kern_malloc.c,v 1.13 1996/02/09 18:59:39 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 struct kmembuckets bucket[MINBUCKET + 16]; 49 struct kmemstats kmemstats[M_LAST]; 50 struct kmemusage *kmemusage; 51 char *kmembase, *kmemlimit; 52 char *memname[] = INITKMEMNAMES; 53 54 #ifdef DIAGNOSTIC 55 /* 56 * This structure provides a set of masks to catch unaligned frees. 57 */ 58 long addrmask[] = { 0, 59 0x00000001, 0x00000003, 0x00000007, 0x0000000f, 60 0x0000001f, 0x0000003f, 0x0000007f, 0x000000ff, 61 0x000001ff, 0x000003ff, 0x000007ff, 0x00000fff, 62 0x00001fff, 0x00003fff, 0x00007fff, 0x0000ffff, 63 }; 64 65 /* 66 * The WEIRD_ADDR is used as known text to copy into free objects so 67 * that modifications after frees can be detected. 68 */ 69 #define WEIRD_ADDR ((unsigned) 0xdeadbeef) 70 #define MAX_COPY 32 71 72 /* 73 * Normally the freelist structure is used only to hold the list pointer 74 * for free objects. However, when running with diagnostics, the first 75 * 8 bytes of the structure is unused except for diagnostic information, 76 * and the free list pointer is at offst 8 in the structure. Since the 77 * first 8 bytes is the portion of the structure most often modified, this 78 * helps to detect memory reuse problems and avoid free list corruption. 79 */ 80 struct freelist { 81 int32_t spare0; 82 int16_t type; 83 int16_t spare1; 84 caddr_t next; 85 }; 86 #else /* !DIAGNOSTIC */ 87 struct freelist { 88 caddr_t next; 89 }; 90 #endif /* DIAGNOSTIC */ 91 92 /* 93 * Allocate a block of memory 94 */ 95 void * 96 malloc(size, type, flags) 97 unsigned long size; 98 int type, flags; 99 { 100 register struct kmembuckets *kbp; 101 register struct kmemusage *kup; 102 register struct freelist *freep; 103 long indx, npg, allocsize; 104 int s; 105 caddr_t va, cp, savedlist; 106 #ifdef DIAGNOSTIC 107 int32_t *end, *lp; 108 int copysize; 109 char *savedtype; 110 #endif 111 #ifdef KMEMSTATS 112 register struct kmemstats *ksp = &kmemstats[type]; 113 114 if (((unsigned long)type) > M_LAST) 115 panic("malloc - bogus type"); 116 #endif 117 indx = BUCKETINDX(size); 118 kbp = &bucket[indx]; 119 s = splimp(); 120 #ifdef KMEMSTATS 121 while (ksp->ks_memuse >= ksp->ks_limit) { 122 if (flags & M_NOWAIT) { 123 splx(s); 124 return ((void *) NULL); 125 } 126 if (ksp->ks_limblocks < 65535) 127 ksp->ks_limblocks++; 128 tsleep((caddr_t)ksp, PSWP+2, memname[type], 0); 129 } 130 ksp->ks_size |= 1 << indx; 131 #endif 132 #ifdef DIAGNOSTIC 133 copysize = 1 << indx < MAX_COPY ? 1 << indx : MAX_COPY; 134 #endif 135 if (kbp->kb_next == NULL) { 136 kbp->kb_last = NULL; 137 if (size > MAXALLOCSAVE) 138 allocsize = roundup(size, CLBYTES); 139 else 140 allocsize = 1 << indx; 141 npg = clrnd(btoc(allocsize)); 142 va = (caddr_t) kmem_malloc(kmem_map, (vm_size_t)ctob(npg), 143 !(flags & M_NOWAIT)); 144 if (va == NULL) { 145 splx(s); 146 return ((void *) NULL); 147 } 148 #ifdef KMEMSTATS 149 kbp->kb_total += kbp->kb_elmpercl; 150 #endif 151 kup = btokup(va); 152 kup->ku_indx = indx; 153 if (allocsize > MAXALLOCSAVE) { 154 if (npg > 65535) 155 panic("malloc: allocation too large"); 156 kup->ku_pagecnt = npg; 157 #ifdef KMEMSTATS 158 ksp->ks_memuse += allocsize; 159 #endif 160 goto out; 161 } 162 #ifdef KMEMSTATS 163 kup->ku_freecnt = kbp->kb_elmpercl; 164 kbp->kb_totalfree += kbp->kb_elmpercl; 165 #endif 166 /* 167 * Just in case we blocked while allocating memory, 168 * and someone else also allocated memory for this 169 * bucket, don't assume the list is still empty. 170 */ 171 savedlist = kbp->kb_next; 172 kbp->kb_next = cp = va + (npg * NBPG) - allocsize; 173 for (;;) { 174 freep = (struct freelist *)cp; 175 #ifdef DIAGNOSTIC 176 /* 177 * Copy in known text to detect modification 178 * after freeing. 179 */ 180 end = (int32_t *)&cp[copysize]; 181 for (lp = (int32_t *)cp; lp < end; lp++) 182 *lp = WEIRD_ADDR; 183 freep->type = M_FREE; 184 #endif /* DIAGNOSTIC */ 185 if (cp <= va) 186 break; 187 cp -= allocsize; 188 freep->next = cp; 189 } 190 freep->next = savedlist; 191 if (kbp->kb_last == NULL) 192 kbp->kb_last = (caddr_t)freep; 193 } 194 va = kbp->kb_next; 195 kbp->kb_next = ((struct freelist *)va)->next; 196 #ifdef DIAGNOSTIC 197 freep = (struct freelist *)va; 198 savedtype = (unsigned)freep->type < M_LAST ? 199 memname[freep->type] : "???"; 200 if (kbp->kb_next && 201 !kernacc(kbp->kb_next, sizeof(struct freelist), 0)) { 202 printf("%s %d of object %p size %d %s %s (invalid addr %p)\n", 203 "Data modified on freelist: word", 204 (int32_t *)&kbp->kb_next - (int32_t *)kbp, va, size, 205 "previous type", savedtype, kbp->kb_next); 206 kbp->kb_next = NULL; 207 } 208 209 /* Fill the fields that we've used with WEIRD_ADDR */ 210 #if BYTE_ORDER == BIG_ENDIAN 211 freep->type = WEIRD_ADDR >> 16; 212 #endif 213 #if BYTE_ORDER == LITTLE_ENDIAN 214 freep->type = (short)WEIRD_ADDR; 215 #endif 216 end = (int32_t *)&freep->next + 217 (sizeof(freep->next) / sizeof(int32_t)); 218 for (lp = (int32_t *)&freep->next; lp < end; lp++) 219 *lp = WEIRD_ADDR; 220 221 /* and check that the data hasn't been modified. */ 222 end = (int32_t *)&va[copysize]; 223 for (lp = (int32_t *)va; lp < end; lp++) { 224 if (*lp == WEIRD_ADDR) 225 continue; 226 printf("%s %d of object %p size %d %s %s (%p != %p)\n", 227 "Data modified on freelist: word", lp - (int32_t *)va, 228 va, size, "previous type", savedtype, (void *)*lp, 229 (void *) WEIRD_ADDR); 230 break; 231 } 232 233 freep->spare0 = 0; 234 #endif /* DIAGNOSTIC */ 235 #ifdef KMEMSTATS 236 kup = btokup(va); 237 if (kup->ku_indx != indx) 238 panic("malloc: wrong bucket"); 239 if (kup->ku_freecnt == 0) 240 panic("malloc: lost data"); 241 kup->ku_freecnt--; 242 kbp->kb_totalfree--; 243 ksp->ks_memuse += 1 << indx; 244 out: 245 kbp->kb_calls++; 246 ksp->ks_inuse++; 247 ksp->ks_calls++; 248 if (ksp->ks_memuse > ksp->ks_maxused) 249 ksp->ks_maxused = ksp->ks_memuse; 250 #else 251 out: 252 #endif 253 splx(s); 254 return ((void *) va); 255 } 256 257 /* 258 * Free a block of memory allocated by malloc. 259 */ 260 void 261 free(addr, type) 262 void *addr; 263 int type; 264 { 265 register struct kmembuckets *kbp; 266 register struct kmemusage *kup; 267 register struct freelist *freep; 268 long size; 269 int s; 270 #ifdef DIAGNOSTIC 271 caddr_t cp; 272 int32_t *end, *lp; 273 long alloc, copysize; 274 #endif 275 #ifdef KMEMSTATS 276 register struct kmemstats *ksp = &kmemstats[type]; 277 #endif 278 279 kup = btokup(addr); 280 size = 1 << kup->ku_indx; 281 kbp = &bucket[kup->ku_indx]; 282 s = splimp(); 283 #ifdef DIAGNOSTIC 284 /* 285 * Check for returns of data that do not point to the 286 * beginning of the allocation. 287 */ 288 if (size > NBPG * CLSIZE) 289 alloc = addrmask[BUCKETINDX(NBPG * CLSIZE)]; 290 else 291 alloc = addrmask[kup->ku_indx]; 292 if (((u_long)addr & alloc) != 0) 293 panic("free: unaligned addr 0x%x, size %d, type %s, mask %d\n", 294 addr, size, memname[type], alloc); 295 #endif /* DIAGNOSTIC */ 296 if (size > MAXALLOCSAVE) { 297 kmem_free(kmem_map, (vm_offset_t)addr, ctob(kup->ku_pagecnt)); 298 #ifdef KMEMSTATS 299 size = kup->ku_pagecnt << PGSHIFT; 300 ksp->ks_memuse -= size; 301 kup->ku_indx = 0; 302 kup->ku_pagecnt = 0; 303 if (ksp->ks_memuse + size >= ksp->ks_limit && 304 ksp->ks_memuse < ksp->ks_limit) 305 wakeup((caddr_t)ksp); 306 ksp->ks_inuse--; 307 kbp->kb_total -= 1; 308 #endif 309 splx(s); 310 return; 311 } 312 freep = (struct freelist *)addr; 313 #ifdef DIAGNOSTIC 314 /* 315 * Check for multiple frees. Use a quick check to see if 316 * it looks free before laboriously searching the freelist. 317 */ 318 if (freep->spare0 == WEIRD_ADDR) { 319 for (cp = kbp->kb_next; cp; cp = *(caddr_t *)cp) { 320 if (addr != cp) 321 continue; 322 printf("multiply freed item %p\n", addr); 323 panic("free: duplicated free"); 324 } 325 } 326 /* 327 * Copy in known text to detect modification after freeing 328 * and to make it look free. Also, save the type being freed 329 * so we can list likely culprit if modification is detected 330 * when the object is reallocated. 331 */ 332 copysize = size < MAX_COPY ? size : MAX_COPY; 333 end = (int32_t *)&((caddr_t)addr)[copysize]; 334 for (lp = (int32_t *)addr; lp < end; lp++) 335 *lp = WEIRD_ADDR; 336 freep->type = type; 337 #endif /* DIAGNOSTIC */ 338 #ifdef KMEMSTATS 339 kup->ku_freecnt++; 340 if (kup->ku_freecnt >= kbp->kb_elmpercl) 341 if (kup->ku_freecnt > kbp->kb_elmpercl) 342 panic("free: multiple frees"); 343 else if (kbp->kb_totalfree > kbp->kb_highwat) 344 kbp->kb_couldfree++; 345 kbp->kb_totalfree++; 346 ksp->ks_memuse -= size; 347 if (ksp->ks_memuse + size >= ksp->ks_limit && 348 ksp->ks_memuse < ksp->ks_limit) 349 wakeup((caddr_t)ksp); 350 ksp->ks_inuse--; 351 #endif 352 if (kbp->kb_next == NULL) 353 kbp->kb_next = addr; 354 else 355 ((struct freelist *)kbp->kb_last)->next = addr; 356 freep->next = NULL; 357 kbp->kb_last = addr; 358 splx(s); 359 } 360 361 /* 362 * Initialize the kernel memory allocator 363 */ 364 void 365 kmeminit() 366 { 367 register long indx; 368 int npg; 369 370 #if ((MAXALLOCSAVE & (MAXALLOCSAVE - 1)) != 0) 371 ERROR!_kmeminit:_MAXALLOCSAVE_not_power_of_2 372 #endif 373 #if (MAXALLOCSAVE > MINALLOCSIZE * 32768) 374 ERROR!_kmeminit:_MAXALLOCSAVE_too_big 375 #endif 376 #if (MAXALLOCSAVE < CLBYTES) 377 ERROR!_kmeminit:_MAXALLOCSAVE_too_small 378 #endif 379 380 if (sizeof(struct freelist) > (1 << MINBUCKET)) 381 panic("minbucket too small/struct freelist too big"); 382 383 npg = VM_KMEM_SIZE/ NBPG; 384 kmemusage = (struct kmemusage *) kmem_alloc(kernel_map, 385 (vm_size_t)(npg * sizeof(struct kmemusage))); 386 kmem_map = kmem_suballoc(kernel_map, (vm_offset_t *)&kmembase, 387 (vm_offset_t *)&kmemlimit, (vm_size_t)(npg * NBPG), FALSE); 388 #ifdef KMEMSTATS 389 for (indx = 0; indx < MINBUCKET + 16; indx++) { 390 if (1 << indx >= CLBYTES) 391 bucket[indx].kb_elmpercl = 1; 392 else 393 bucket[indx].kb_elmpercl = CLBYTES / (1 << indx); 394 bucket[indx].kb_highwat = 5 * bucket[indx].kb_elmpercl; 395 } 396 for (indx = 0; indx < M_LAST; indx++) 397 kmemstats[indx].ks_limit = npg * NBPG * 6 / 10; 398 #endif 399 } 400
Indexes created Sun Sep 21 16:09:51 GMT 2025