kern_malloc.c revision 1.1.1.2
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 8.3 (Berkeley) 1/4/94 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 KMEMSTATS 107 register struct kmemstats *ksp = &kmemstats[type]; 108 109 if (((unsigned long)type) > M_LAST) 110 panic("malloc - bogus type"); 111 #endif 112 indx = BUCKETINDX(size); 113 kbp = &bucket[indx]; 114 s = splimp(); 115 #ifdef KMEMSTATS 116 while (ksp->ks_memuse >= ksp->ks_limit) { 117 if (flags & M_NOWAIT) { 118 splx(s); 119 return ((void *) NULL); 120 } 121 if (ksp->ks_limblocks < 65535) 122 ksp->ks_limblocks++; 123 tsleep((caddr_t)ksp, PSWP+2, memname[type], 0); 124 } 125 ksp->ks_size |= 1 << indx; 126 #endif 127 #ifdef DIAGNOSTIC 128 copysize = 1 << indx < MAX_COPY ? 1 << indx : MAX_COPY; 129 #endif 130 if (kbp->kb_next == NULL) { 131 kbp->kb_last = NULL; 132 if (size > MAXALLOCSAVE) 133 allocsize = roundup(size, CLBYTES); 134 else 135 allocsize = 1 << indx; 136 npg = clrnd(btoc(allocsize)); 137 va = (caddr_t) kmem_malloc(kmem_map, (vm_size_t)ctob(npg), 138 !(flags & M_NOWAIT)); 139 if (va == NULL) { 140 splx(s); 141 return ((void *) NULL); 142 } 143 #ifdef KMEMSTATS 144 kbp->kb_total += kbp->kb_elmpercl; 145 #endif 146 kup = btokup(va); 147 kup->ku_indx = indx; 148 if (allocsize > MAXALLOCSAVE) { 149 if (npg > 65535) 150 panic("malloc: allocation too large"); 151 kup->ku_pagecnt = npg; 152 #ifdef KMEMSTATS 153 ksp->ks_memuse += allocsize; 154 #endif 155 goto out; 156 } 157 #ifdef KMEMSTATS 158 kup->ku_freecnt = kbp->kb_elmpercl; 159 kbp->kb_totalfree += kbp->kb_elmpercl; 160 #endif 161 /* 162 * Just in case we blocked while allocating memory, 163 * and someone else also allocated memory for this 164 * bucket, don't assume the list is still empty. 165 */ 166 savedlist = kbp->kb_next; 167 kbp->kb_next = cp = va + (npg * NBPG) - allocsize; 168 for (;;) { 169 freep = (struct freelist *)cp; 170 #ifdef DIAGNOSTIC 171 /* 172 * Copy in known text to detect modification 173 * after freeing. 174 */ 175 end = (long *)&cp[copysize]; 176 for (lp = (long *)cp; lp < end; lp++) 177 *lp = WEIRD_ADDR; 178 freep->type = M_FREE; 179 #endif /* DIAGNOSTIC */ 180 if (cp <= va) 181 break; 182 cp -= allocsize; 183 freep->next = cp; 184 } 185 freep->next = savedlist; 186 if (kbp->kb_last == NULL) 187 kbp->kb_last = (caddr_t)freep; 188 } 189 va = kbp->kb_next; 190 kbp->kb_next = ((struct freelist *)va)->next; 191 #ifdef DIAGNOSTIC 192 freep = (struct freelist *)va; 193 savedtype = (unsigned)freep->type < M_LAST ? 194 memname[freep->type] : "???"; 195 if (kbp->kb_next && 196 !kernacc(kbp->kb_next, sizeof(struct freelist), 0)) { 197 printf("%s of object 0x%x size %d %s %s (invalid addr 0x%x)\n", 198 "Data modified on freelist: word 2.5", va, size, 199 "previous type", savedtype, kbp->kb_next); 200 kbp->kb_next = NULL; 201 } 202 #if BYTE_ORDER == BIG_ENDIAN 203 freep->type = WEIRD_ADDR >> 16; 204 #endif 205 #if BYTE_ORDER == LITTLE_ENDIAN 206 freep->type = (short)WEIRD_ADDR; 207 #endif 208 if (((long)(&freep->next)) & 0x2) 209 freep->next = (caddr_t)((WEIRD_ADDR >> 16)|(WEIRD_ADDR << 16)); 210 else 211 freep->next = (caddr_t)WEIRD_ADDR; 212 end = (long *)&va[copysize]; 213 for (lp = (long *)va; lp < end; lp++) { 214 if (*lp == WEIRD_ADDR) 215 continue; 216 printf("%s %d of object 0x%x size %d %s %s (0x%x != 0x%x)\n", 217 "Data modified on freelist: word", lp - (long *)va, 218 va, size, "previous type", savedtype, *lp, WEIRD_ADDR); 219 break; 220 } 221 freep->spare0 = 0; 222 #endif /* DIAGNOSTIC */ 223 #ifdef KMEMSTATS 224 kup = btokup(va); 225 if (kup->ku_indx != indx) 226 panic("malloc: wrong bucket"); 227 if (kup->ku_freecnt == 0) 228 panic("malloc: lost data"); 229 kup->ku_freecnt--; 230 kbp->kb_totalfree--; 231 ksp->ks_memuse += 1 << indx; 232 out: 233 kbp->kb_calls++; 234 ksp->ks_inuse++; 235 ksp->ks_calls++; 236 if (ksp->ks_memuse > ksp->ks_maxused) 237 ksp->ks_maxused = ksp->ks_memuse; 238 #else 239 out: 240 #endif 241 splx(s); 242 return ((void *) va); 243 } 244 245 /* 246 * Free a block of memory allocated by malloc. 247 */ 248 void 249 free(addr, type) 250 void *addr; 251 int type; 252 { 253 register struct kmembuckets *kbp; 254 register struct kmemusage *kup; 255 register struct freelist *freep; 256 long size; 257 int s; 258 #ifdef DIAGNOSTIC 259 caddr_t cp; 260 long *end, *lp, alloc, copysize; 261 #endif 262 #ifdef KMEMSTATS 263 register struct kmemstats *ksp = &kmemstats[type]; 264 #endif 265 266 kup = btokup(addr); 267 size = 1 << kup->ku_indx; 268 kbp = &bucket[kup->ku_indx]; 269 s = splimp(); 270 #ifdef DIAGNOSTIC 271 /* 272 * Check for returns of data that do not point to the 273 * beginning of the allocation. 274 */ 275 if (size > NBPG * CLSIZE) 276 alloc = addrmask[BUCKETINDX(NBPG * CLSIZE)]; 277 else 278 alloc = addrmask[kup->ku_indx]; 279 if (((u_long)addr & alloc) != 0) 280 panic("free: unaligned addr 0x%x, size %d, type %s, mask %d\n", 281 addr, size, memname[type], alloc); 282 #endif /* DIAGNOSTIC */ 283 if (size > MAXALLOCSAVE) { 284 kmem_free(kmem_map, (vm_offset_t)addr, ctob(kup->ku_pagecnt)); 285 #ifdef KMEMSTATS 286 size = kup->ku_pagecnt << PGSHIFT; 287 ksp->ks_memuse -= size; 288 kup->ku_indx = 0; 289 kup->ku_pagecnt = 0; 290 if (ksp->ks_memuse + size >= ksp->ks_limit && 291 ksp->ks_memuse < ksp->ks_limit) 292 wakeup((caddr_t)ksp); 293 ksp->ks_inuse--; 294 kbp->kb_total -= 1; 295 #endif 296 splx(s); 297 return; 298 } 299 freep = (struct freelist *)addr; 300 #ifdef DIAGNOSTIC 301 /* 302 * Check for multiple frees. Use a quick check to see if 303 * it looks free before laboriously searching the freelist. 304 */ 305 if (freep->spare0 == WEIRD_ADDR) { 306 for (cp = kbp->kb_next; cp; cp = *(caddr_t *)cp) { 307 if (addr != cp) 308 continue; 309 printf("multiply freed item 0x%x\n", addr); 310 panic("free: duplicated free"); 311 } 312 } 313 /* 314 * Copy in known text to detect modification after freeing 315 * and to make it look free. Also, save the type being freed 316 * so we can list likely culprit if modification is detected 317 * when the object is reallocated. 318 */ 319 copysize = size < MAX_COPY ? size : MAX_COPY; 320 end = (long *)&((caddr_t)addr)[copysize]; 321 for (lp = (long *)addr; lp < end; lp++) 322 *lp = WEIRD_ADDR; 323 freep->type = type; 324 #endif /* DIAGNOSTIC */ 325 #ifdef KMEMSTATS 326 kup->ku_freecnt++; 327 if (kup->ku_freecnt >= kbp->kb_elmpercl) 328 if (kup->ku_freecnt > kbp->kb_elmpercl) 329 panic("free: multiple frees"); 330 else if (kbp->kb_totalfree > kbp->kb_highwat) 331 kbp->kb_couldfree++; 332 kbp->kb_totalfree++; 333 ksp->ks_memuse -= size; 334 if (ksp->ks_memuse + size >= ksp->ks_limit && 335 ksp->ks_memuse < ksp->ks_limit) 336 wakeup((caddr_t)ksp); 337 ksp->ks_inuse--; 338 #endif 339 if (kbp->kb_next == NULL) 340 kbp->kb_next = addr; 341 else 342 ((struct freelist *)kbp->kb_last)->next = addr; 343 freep->next = NULL; 344 kbp->kb_last = addr; 345 splx(s); 346 } 347 348 /* 349 * Initialize the kernel memory allocator 350 */ 351 kmeminit() 352 { 353 register long indx; 354 int npg; 355 356 #if ((MAXALLOCSAVE & (MAXALLOCSAVE - 1)) != 0) 357 ERROR!_kmeminit:_MAXALLOCSAVE_not_power_of_2 358 #endif 359 #if (MAXALLOCSAVE > MINALLOCSIZE * 32768) 360 ERROR!_kmeminit:_MAXALLOCSAVE_too_big 361 #endif 362 #if (MAXALLOCSAVE < CLBYTES) 363 ERROR!_kmeminit:_MAXALLOCSAVE_too_small 364 #endif 365 npg = VM_KMEM_SIZE/ NBPG; 366 kmemusage = (struct kmemusage *) kmem_alloc(kernel_map, 367 (vm_size_t)(npg * sizeof(struct kmemusage))); 368 kmem_map = kmem_suballoc(kernel_map, (vm_offset_t *)&kmembase, 369 (vm_offset_t *)&kmemlimit, (vm_size_t)(npg * NBPG), FALSE); 370 #ifdef KMEMSTATS 371 for (indx = 0; indx < MINBUCKET + 16; indx++) { 372 if (1 << indx >= CLBYTES) 373 bucket[indx].kb_elmpercl = 1; 374 else 375 bucket[indx].kb_elmpercl = CLBYTES / (1 << indx); 376 bucket[indx].kb_highwat = 5 * bucket[indx].kb_elmpercl; 377 } 378 for (indx = 0; indx < M_LAST; indx++) 379 kmemstats[indx].ks_limit = npg * NBPG * 6 / 10; 380 #endif 381 } 382
Indexes created Sat Sep 20 22:09:52 GMT 2025