kern_malloc.c revision 1.1.1.3
1 /* 2 * Copyright (c) 1987, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)kern_malloc.c 8.4 (Berkeley) 5/20/95 34 */ 35 36 #include <sys/param.h> 37 #include <sys/proc.h> 38 #include <sys/map.h> 39 #include <sys/kernel.h> 40 #include <sys/malloc.h> 41 42 #include <vm/vm.h> 43 #include <vm/vm_kern.h> 44 45 struct kmembuckets bucket[MINBUCKET + 16]; 46 struct kmemstats kmemstats[M_LAST]; 47 struct kmemusage *kmemusage; 48 char *kmembase, *kmemlimit; 49 char *memname[] = INITKMEMNAMES; 50 51 #ifdef DIAGNOSTIC 52 /* 53 * This structure provides a set of masks to catch unaligned frees. 54 */ 55 long addrmask[] = { 0, 56 0x00000001, 0x00000003, 0x00000007, 0x0000000f, 57 0x0000001f, 0x0000003f, 0x0000007f, 0x000000ff, 58 0x000001ff, 0x000003ff, 0x000007ff, 0x00000fff, 59 0x00001fff, 0x00003fff, 0x00007fff, 0x0000ffff, 60 }; 61 62 /* 63 * The WEIRD_ADDR is used as known text to copy into free objects so 64 * that modifications after frees can be detected. 65 */ 66 #define WEIRD_ADDR 0xdeadbeef 67 #define MAX_COPY 32 68 69 /* 70 * Normally the first word of the structure is used to hold the list 71 * pointer for free objects. However, when running with diagnostics, 72 * we use the third and fourth fields, so as to catch modifications 73 * in the most commonly trashed first two words. 74 */ 75 struct freelist { 76 long spare0; 77 short type; 78 long spare1; 79 caddr_t next; 80 }; 81 #else /* !DIAGNOSTIC */ 82 struct freelist { 83 caddr_t next; 84 }; 85 #endif /* DIAGNOSTIC */ 86 87 /* 88 * Allocate a block of memory 89 */ 90 void * 91 malloc(size, type, flags) 92 unsigned long size; 93 int type, flags; 94 { 95 register struct kmembuckets *kbp; 96 register struct kmemusage *kup; 97 register struct freelist *freep; 98 long indx, npg, allocsize; 99 int s; 100 caddr_t va, cp, savedlist; 101 #ifdef DIAGNOSTIC 102 long *end, *lp; 103 int copysize; 104 char *savedtype; 105 #endif 106 #ifdef DEBUG 107 extern int simplelockrecurse; 108 #endif 109 #ifdef KMEMSTATS 110 register struct kmemstats *ksp = &kmemstats[type]; 111 112 if (((unsigned long)type) > M_LAST) 113 panic("malloc - bogus type"); 114 #endif 115 indx = BUCKETINDX(size); 116 kbp = &bucket[indx]; 117 s = splimp(); 118 #ifdef KMEMSTATS 119 while (ksp->ks_memuse >= ksp->ks_limit) { 120 if (flags & M_NOWAIT) { 121 splx(s); 122 return ((void *) NULL); 123 } 124 if (ksp->ks_limblocks < 65535) 125 ksp->ks_limblocks++; 126 tsleep((caddr_t)ksp, PSWP+2, memname[type], 0); 127 } 128 ksp->ks_size |= 1 << indx; 129 #endif 130 #ifdef DIAGNOSTIC 131 copysize = 1 << indx < MAX_COPY ? 1 << indx : MAX_COPY; 132 #endif 133 #ifdef DEBUG 134 if (flags & M_NOWAIT) 135 simplelockrecurse++; 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 #ifdef DEBUG 149 if (flags & M_NOWAIT) 150 simplelockrecurse--; 151 #endif 152 return ((void *) NULL); 153 } 154 #ifdef KMEMSTATS 155 kbp->kb_total += kbp->kb_elmpercl; 156 #endif 157 kup = btokup(va); 158 kup->ku_indx = indx; 159 if (allocsize > MAXALLOCSAVE) { 160 if (npg > 65535) 161 panic("malloc: allocation too large"); 162 kup->ku_pagecnt = npg; 163 #ifdef KMEMSTATS 164 ksp->ks_memuse += allocsize; 165 #endif 166 goto out; 167 } 168 #ifdef KMEMSTATS 169 kup->ku_freecnt = kbp->kb_elmpercl; 170 kbp->kb_totalfree += kbp->kb_elmpercl; 171 #endif 172 /* 173 * Just in case we blocked while allocating memory, 174 * and someone else also allocated memory for this 175 * bucket, don't assume the list is still empty. 176 */ 177 savedlist = kbp->kb_next; 178 kbp->kb_next = cp = va + (npg * NBPG) - allocsize; 179 for (;;) { 180 freep = (struct freelist *)cp; 181 #ifdef DIAGNOSTIC 182 /* 183 * Copy in known text to detect modification 184 * after freeing. 185 */ 186 end = (long *)&cp[copysize]; 187 for (lp = (long *)cp; lp < end; lp++) 188 *lp = WEIRD_ADDR; 189 freep->type = M_FREE; 190 #endif /* DIAGNOSTIC */ 191 if (cp <= va) 192 break; 193 cp -= allocsize; 194 freep->next = cp; 195 } 196 freep->next = savedlist; 197 if (kbp->kb_last == NULL) 198 kbp->kb_last = (caddr_t)freep; 199 } 200 va = kbp->kb_next; 201 kbp->kb_next = ((struct freelist *)va)->next; 202 #ifdef DIAGNOSTIC 203 freep = (struct freelist *)va; 204 savedtype = (unsigned)freep->type < M_LAST ? 205 memname[freep->type] : "???"; 206 if (kbp->kb_next && 207 !kernacc(kbp->kb_next, sizeof(struct freelist), 0)) { 208 printf("%s of object 0x%x size %d %s %s (invalid addr 0x%x)\n", 209 "Data modified on freelist: word 2.5", va, size, 210 "previous type", savedtype, kbp->kb_next); 211 kbp->kb_next = NULL; 212 } 213 #if BYTE_ORDER == BIG_ENDIAN 214 freep->type = WEIRD_ADDR >> 16; 215 #endif 216 #if BYTE_ORDER == LITTLE_ENDIAN 217 freep->type = (short)WEIRD_ADDR; 218 #endif 219 if (((long)(&freep->next)) & 0x2) 220 freep->next = (caddr_t)((WEIRD_ADDR >> 16)|(WEIRD_ADDR << 16)); 221 else 222 freep->next = (caddr_t)WEIRD_ADDR; 223 end = (long *)&va[copysize]; 224 for (lp = (long *)va; lp < end; lp++) { 225 if (*lp == WEIRD_ADDR) 226 continue; 227 printf("%s %d of object 0x%x size %d %s %s (0x%x != 0x%x)\n", 228 "Data modified on freelist: word", lp - (long *)va, 229 va, size, "previous type", savedtype, *lp, WEIRD_ADDR); 230 break; 231 } 232 freep->spare0 = 0; 233 #endif /* DIAGNOSTIC */ 234 #ifdef KMEMSTATS 235 kup = btokup(va); 236 if (kup->ku_indx != indx) 237 panic("malloc: wrong bucket"); 238 if (kup->ku_freecnt == 0) 239 panic("malloc: lost data"); 240 kup->ku_freecnt--; 241 kbp->kb_totalfree--; 242 ksp->ks_memuse += 1 << indx; 243 out: 244 kbp->kb_calls++; 245 ksp->ks_inuse++; 246 ksp->ks_calls++; 247 if (ksp->ks_memuse > ksp->ks_maxused) 248 ksp->ks_maxused = ksp->ks_memuse; 249 #else 250 out: 251 #endif 252 splx(s); 253 #ifdef DEBUG 254 if (flags & M_NOWAIT) 255 simplelockrecurse--; 256 #endif 257 return ((void *) va); 258 } 259 260 /* 261 * Free a block of memory allocated by malloc. 262 */ 263 void 264 free(addr, type) 265 void *addr; 266 int type; 267 { 268 register struct kmembuckets *kbp; 269 register struct kmemusage *kup; 270 register struct freelist *freep; 271 long size; 272 int s; 273 #ifdef DIAGNOSTIC 274 caddr_t cp; 275 long *end, *lp, 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 0x%x\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 = (long *)&((caddr_t)addr)[copysize]; 336 for (lp = (long *)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 kmeminit() 367 { 368 register long indx; 369 int npg; 370 371 #if ((MAXALLOCSAVE & (MAXALLOCSAVE - 1)) != 0) 372 ERROR!_kmeminit:_MAXALLOCSAVE_not_power_of_2 373 #endif 374 #if (MAXALLOCSAVE > MINALLOCSIZE * 32768) 375 ERROR!_kmeminit:_MAXALLOCSAVE_too_big 376 #endif 377 #if (MAXALLOCSAVE < CLBYTES) 378 ERROR!_kmeminit:_MAXALLOCSAVE_too_small 379 #endif 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 15:09:59 GMT 2025