kern_malloc.c revision 1.11
1 /* $NetBSD: kern_malloc.c,v 1.11 1995/05/01 22:39:11 cgd 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 44 #include <vm/vm.h> 45 #include <vm/vm_kern.h> 46 47 struct kmembuckets bucket[MINBUCKET + 16]; 48 struct kmemstats kmemstats[M_LAST]; 49 struct kmemusage *kmemusage; 50 char *kmembase, *kmemlimit; 51 char *memname[] = INITKMEMNAMES; 52 53 #ifdef DIAGNOSTIC 54 /* 55 * This structure provides a set of masks to catch unaligned frees. 56 */ 57 long addrmask[] = { 0, 58 0x00000001, 0x00000003, 0x00000007, 0x0000000f, 59 0x0000001f, 0x0000003f, 0x0000007f, 0x000000ff, 60 0x000001ff, 0x000003ff, 0x000007ff, 0x00000fff, 61 0x00001fff, 0x00003fff, 0x00007fff, 0x0000ffff, 62 }; 63 64 /* 65 * The WEIRD_ADDR is used as known text to copy into free objects so 66 * that modifications after frees can be detected. 67 */ 68 #define WEIRD_ADDR 0xdeadbeef 69 #define MAX_COPY 32 70 71 /* 72 * Normally the freelist structure is used only to hold the list pointer 73 * for free objects. However, when running with diagnostics, the first 74 * 8 bytes of the structure is unused except for diagnostic information, 75 * and the free list pointer is at offst 8 in the structure. Since the 76 * first 8 bytes is the portion of the structure most often modified, this 77 * helps to detect memory reuse problems and avoid free list corruption. 78 */ 79 struct freelist { 80 int32_t spare0; 81 int16_t type; 82 int16_t spare1; 83 caddr_t next; 84 }; 85 #else /* !DIAGNOSTIC */ 86 struct freelist { 87 caddr_t next; 88 }; 89 #endif /* DIAGNOSTIC */ 90 91 /* 92 * Allocate a block of memory 93 */ 94 void * 95 malloc(size, type, flags) 96 unsigned long size; 97 int type, flags; 98 { 99 register struct kmembuckets *kbp; 100 register struct kmemusage *kup; 101 register struct freelist *freep; 102 long indx, npg, allocsize; 103 int s; 104 caddr_t va, cp, savedlist; 105 #ifdef DIAGNOSTIC 106 int32_t *end, *lp; 107 int copysize; 108 char *savedtype; 109 #endif 110 #ifdef KMEMSTATS 111 register struct kmemstats *ksp = &kmemstats[type]; 112 113 if (((unsigned long)type) > M_LAST) 114 panic("malloc - bogus type"); 115 #endif 116 indx = BUCKETINDX(size); 117 kbp = &bucket[indx]; 118 s = splimp(); 119 #ifdef KMEMSTATS 120 while (ksp->ks_memuse >= ksp->ks_limit) { 121 if (flags & M_NOWAIT) { 122 splx(s); 123 return ((void *) NULL); 124 } 125 if (ksp->ks_limblocks < 65535) 126 ksp->ks_limblocks++; 127 tsleep((caddr_t)ksp, PSWP+2, memname[type], 0); 128 } 129 ksp->ks_size |= 1 << indx; 130 #endif 131 #ifdef DIAGNOSTIC 132 copysize = 1 << indx < MAX_COPY ? 1 << indx : MAX_COPY; 133 #endif 134 if (kbp->kb_next == NULL) { 135 kbp->kb_last = NULL; 136 if (size > MAXALLOCSAVE) 137 allocsize = roundup(size, CLBYTES); 138 else 139 allocsize = 1 << indx; 140 npg = clrnd(btoc(allocsize)); 141 va = (caddr_t) kmem_malloc(kmem_map, (vm_size_t)ctob(npg), 142 !(flags & M_NOWAIT)); 143 if (va == NULL) { 144 splx(s); 145 return ((void *) NULL); 146 } 147 #ifdef KMEMSTATS 148 kbp->kb_total += kbp->kb_elmpercl; 149 #endif 150 kup = btokup(va); 151 kup->ku_indx = indx; 152 if (allocsize > MAXALLOCSAVE) { 153 if (npg > 65535) 154 panic("malloc: allocation too large"); 155 kup->ku_pagecnt = npg; 156 #ifdef KMEMSTATS 157 ksp->ks_memuse += allocsize; 158 #endif 159 goto out; 160 } 161 #ifdef KMEMSTATS 162 kup->ku_freecnt = kbp->kb_elmpercl; 163 kbp->kb_totalfree += kbp->kb_elmpercl; 164 #endif 165 /* 166 * Just in case we blocked while allocating memory, 167 * and someone else also allocated memory for this 168 * bucket, don't assume the list is still empty. 169 */ 170 savedlist = kbp->kb_next; 171 kbp->kb_next = cp = va + (npg * NBPG) - allocsize; 172 for (;;) { 173 freep = (struct freelist *)cp; 174 #ifdef DIAGNOSTIC 175 /* 176 * Copy in known text to detect modification 177 * after freeing. 178 */ 179 end = (int32_t *)&cp[copysize]; 180 for (lp = (int32_t *)cp; lp < end; lp++) 181 *lp = WEIRD_ADDR; 182 freep->type = M_FREE; 183 #endif /* DIAGNOSTIC */ 184 if (cp <= va) 185 break; 186 cp -= allocsize; 187 freep->next = cp; 188 } 189 freep->next = savedlist; 190 if (kbp->kb_last == NULL) 191 kbp->kb_last = (caddr_t)freep; 192 } 193 va = kbp->kb_next; 194 kbp->kb_next = ((struct freelist *)va)->next; 195 #ifdef DIAGNOSTIC 196 freep = (struct freelist *)va; 197 savedtype = (unsigned)freep->type < M_LAST ? 198 memname[freep->type] : "???"; 199 if (kbp->kb_next && 200 !kernacc(kbp->kb_next, sizeof(struct freelist), 0)) { 201 printf("%s %d of object %p size %d %s %s (invalid addr %p)\n", 202 "Data modified on freelist: word", 203 (int32_t *)&kbp->kb_next - (int32_t *)kbp, va, size, 204 "previous type", savedtype, kbp->kb_next); 205 kbp->kb_next = NULL; 206 } 207 208 /* Fill the fields that we've used with WEIRD_ADDR */ 209 #if BYTE_ORDER == BIG_ENDIAN 210 freep->type = WEIRD_ADDR >> 16; 211 #endif 212 #if BYTE_ORDER == LITTLE_ENDIAN 213 freep->type = (short)WEIRD_ADDR; 214 #endif 215 end = (int32_t *)&freep->next + 216 (sizeof(freep->next) / sizeof(int32_t)); 217 for (lp = (int32_t *)&freep->next; lp < end; lp++) 218 *lp = WEIRD_ADDR; 219 220 /* and check that the data hasn't been modified. */ 221 end = (int32_t *)&va[copysize]; 222 for (lp = (int32_t *)va; lp < end; lp++) { 223 if (*lp == WEIRD_ADDR) 224 continue; 225 printf("%s %d of object %p size %d %s %s (%p != %p)\n", 226 "Data modified on freelist: word", lp - (int32_t *)va, 227 va, size, "previous type", savedtype, *lp, WEIRD_ADDR); 228 break; 229 } 230 231 freep->spare0 = 0; 232 #endif /* DIAGNOSTIC */ 233 #ifdef KMEMSTATS 234 kup = btokup(va); 235 if (kup->ku_indx != indx) 236 panic("malloc: wrong bucket"); 237 if (kup->ku_freecnt == 0) 238 panic("malloc: lost data"); 239 kup->ku_freecnt--; 240 kbp->kb_totalfree--; 241 ksp->ks_memuse += 1 << indx; 242 out: 243 kbp->kb_calls++; 244 ksp->ks_inuse++; 245 ksp->ks_calls++; 246 if (ksp->ks_memuse > ksp->ks_maxused) 247 ksp->ks_maxused = ksp->ks_memuse; 248 #else 249 out: 250 #endif 251 splx(s); 252 return ((void *) va); 253 } 254 255 /* 256 * Free a block of memory allocated by malloc. 257 */ 258 void 259 free(addr, type) 260 void *addr; 261 int type; 262 { 263 register struct kmembuckets *kbp; 264 register struct kmemusage *kup; 265 register struct freelist *freep; 266 long size; 267 int s; 268 #ifdef DIAGNOSTIC 269 caddr_t cp; 270 int32_t *end, *lp; 271 long alloc, copysize; 272 #endif 273 #ifdef KMEMSTATS 274 register struct kmemstats *ksp = &kmemstats[type]; 275 #endif 276 277 kup = btokup(addr); 278 size = 1 << kup->ku_indx; 279 kbp = &bucket[kup->ku_indx]; 280 s = splimp(); 281 #ifdef DIAGNOSTIC 282 /* 283 * Check for returns of data that do not point to the 284 * beginning of the allocation. 285 */ 286 if (size > NBPG * CLSIZE) 287 alloc = addrmask[BUCKETINDX(NBPG * CLSIZE)]; 288 else 289 alloc = addrmask[kup->ku_indx]; 290 if (((u_long)addr & alloc) != 0) 291 panic("free: unaligned addr 0x%x, size %d, type %s, mask %d\n", 292 addr, size, memname[type], alloc); 293 #endif /* DIAGNOSTIC */ 294 if (size > MAXALLOCSAVE) { 295 kmem_free(kmem_map, (vm_offset_t)addr, ctob(kup->ku_pagecnt)); 296 #ifdef KMEMSTATS 297 size = kup->ku_pagecnt << PGSHIFT; 298 ksp->ks_memuse -= size; 299 kup->ku_indx = 0; 300 kup->ku_pagecnt = 0; 301 if (ksp->ks_memuse + size >= ksp->ks_limit && 302 ksp->ks_memuse < ksp->ks_limit) 303 wakeup((caddr_t)ksp); 304 ksp->ks_inuse--; 305 kbp->kb_total -= 1; 306 #endif 307 splx(s); 308 return; 309 } 310 freep = (struct freelist *)addr; 311 #ifdef DIAGNOSTIC 312 /* 313 * Check for multiple frees. Use a quick check to see if 314 * it looks free before laboriously searching the freelist. 315 */ 316 if (freep->spare0 == WEIRD_ADDR) { 317 for (cp = kbp->kb_next; cp; cp = *(caddr_t *)cp) { 318 if (addr != cp) 319 continue; 320 printf("multiply freed item %p\n", addr); 321 panic("free: duplicated free"); 322 } 323 } 324 /* 325 * Copy in known text to detect modification after freeing 326 * and to make it look free. Also, save the type being freed 327 * so we can list likely culprit if modification is detected 328 * when the object is reallocated. 329 */ 330 copysize = size < MAX_COPY ? size : MAX_COPY; 331 end = (int32_t *)&((caddr_t)addr)[copysize]; 332 for (lp = (int32_t *)addr; lp < end; lp++) 333 *lp = WEIRD_ADDR; 334 freep->type = type; 335 #endif /* DIAGNOSTIC */ 336 #ifdef KMEMSTATS 337 kup->ku_freecnt++; 338 if (kup->ku_freecnt >= kbp->kb_elmpercl) 339 if (kup->ku_freecnt > kbp->kb_elmpercl) 340 panic("free: multiple frees"); 341 else if (kbp->kb_totalfree > kbp->kb_highwat) 342 kbp->kb_couldfree++; 343 kbp->kb_totalfree++; 344 ksp->ks_memuse -= size; 345 if (ksp->ks_memuse + size >= ksp->ks_limit && 346 ksp->ks_memuse < ksp->ks_limit) 347 wakeup((caddr_t)ksp); 348 ksp->ks_inuse--; 349 #endif 350 if (kbp->kb_next == NULL) 351 kbp->kb_next = addr; 352 else 353 ((struct freelist *)kbp->kb_last)->next = addr; 354 freep->next = NULL; 355 kbp->kb_last = addr; 356 splx(s); 357 } 358 359 /* 360 * Initialize the kernel memory allocator 361 */ 362 kmeminit() 363 { 364 register long indx; 365 int npg; 366 367 #if ((MAXALLOCSAVE & (MAXALLOCSAVE - 1)) != 0) 368 ERROR!_kmeminit:_MAXALLOCSAVE_not_power_of_2 369 #endif 370 #if (MAXALLOCSAVE > MINALLOCSIZE * 32768) 371 ERROR!_kmeminit:_MAXALLOCSAVE_too_big 372 #endif 373 #if (MAXALLOCSAVE < CLBYTES) 374 ERROR!_kmeminit:_MAXALLOCSAVE_too_small 375 #endif 376 377 if (sizeof(struct freelist) > (1 << MINBUCKET)) 378 panic("minbucket too small/struct freelist too big"); 379 380 npg = VM_KMEM_SIZE/ NBPG; 381 kmemusage = (struct kmemusage *) kmem_alloc(kernel_map, 382 (vm_size_t)(npg * sizeof(struct kmemusage))); 383 kmem_map = kmem_suballoc(kernel_map, (vm_offset_t *)&kmembase, 384 (vm_offset_t *)&kmemlimit, (vm_size_t)(npg * NBPG), FALSE); 385 #ifdef KMEMSTATS 386 for (indx = 0; indx < MINBUCKET + 16; indx++) { 387 if (1 << indx >= CLBYTES) 388 bucket[indx].kb_elmpercl = 1; 389 else 390 bucket[indx].kb_elmpercl = CLBYTES / (1 << indx); 391 bucket[indx].kb_highwat = 5 * bucket[indx].kb_elmpercl; 392 } 393 for (indx = 0; indx < M_LAST; indx++) 394 kmemstats[indx].ks_limit = npg * NBPG * 6 / 10; 395 #endif 396 } 397
Indexes created Sun Sep 21 20:09:37 GMT 2025