kern_malloc.c revision 1.8
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 * from: @(#)kern_malloc.c 8.3 (Berkeley) 1/4/94 34 * $Id: kern_malloc.c,v 1.8 1994/05/13 08:32:17 cgd Exp $ 35 */ 36 37 #include <sys/param.h> 38 #include <sys/proc.h> 39 #include <sys/map.h> 40 #include <sys/kernel.h> 41 #include <sys/malloc.h> 42 43 #include <vm/vm.h> 44 #include <vm/vm_kern.h> 45 46 struct kmembuckets bucket[MINBUCKET + 16]; 47 struct kmemstats kmemstats[M_LAST]; 48 struct kmemusage *kmemusage; 49 char *kmembase, *kmemlimit; 50 char *memname[] = INITKMEMNAMES; 51 52 #ifdef DIAGNOSTIC 53 /* 54 * This structure provides a set of masks to catch unaligned frees. 55 */ 56 long addrmask[] = { 0, 57 0x00000001, 0x00000003, 0x00000007, 0x0000000f, 58 0x0000001f, 0x0000003f, 0x0000007f, 0x000000ff, 59 0x000001ff, 0x000003ff, 0x000007ff, 0x00000fff, 60 0x00001fff, 0x00003fff, 0x00007fff, 0x0000ffff, 61 }; 62 63 /* 64 * The WEIRD_ADDR is used as known text to copy into free objects so 65 * that modifications after frees can be detected. 66 */ 67 #define WEIRD_ADDR 0xdeadbeef 68 #define MAX_COPY 32 69 70 /* 71 * Normally the first word of the structure is used to hold the list 72 * pointer for free objects. However, when running with diagnostics, 73 * we use the third and fourth fields, so as to catch modifications 74 * in the most commonly trashed first two words. 75 */ 76 struct freelist { 77 long spare0; 78 short type; 79 long spare1; 80 caddr_t next; 81 }; 82 #else /* !DIAGNOSTIC */ 83 struct freelist { 84 caddr_t next; 85 }; 86 #endif /* DIAGNOSTIC */ 87 88 /* 89 * Allocate a block of memory 90 */ 91 void * 92 malloc(size, type, flags) 93 unsigned long size; 94 int type, flags; 95 { 96 register struct kmembuckets *kbp; 97 register struct kmemusage *kup; 98 register struct freelist *freep; 99 long indx, npg, allocsize; 100 int s; 101 caddr_t va, cp, savedlist; 102 #ifdef DIAGNOSTIC 103 long *end, *lp; 104 int copysize; 105 char *savedtype; 106 #endif 107 #ifdef KMEMSTATS 108 register struct kmemstats *ksp = &kmemstats[type]; 109 110 if (((unsigned long)type) > M_LAST) 111 panic("malloc - bogus type"); 112 #endif 113 indx = BUCKETINDX(size); 114 kbp = &bucket[indx]; 115 s = splimp(); 116 #ifdef KMEMSTATS 117 while (ksp->ks_memuse >= ksp->ks_limit) { 118 if (flags & M_NOWAIT) { 119 splx(s); 120 return ((void *) NULL); 121 } 122 if (ksp->ks_limblocks < 65535) 123 ksp->ks_limblocks++; 124 tsleep((caddr_t)ksp, PSWP+2, memname[type], 0); 125 } 126 ksp->ks_size |= 1 << indx; 127 #endif 128 #ifdef DIAGNOSTIC 129 copysize = 1 << indx < MAX_COPY ? 1 << indx : MAX_COPY; 130 #endif 131 if (kbp->kb_next == NULL) { 132 kbp->kb_last = NULL; 133 if (size > MAXALLOCSAVE) 134 allocsize = roundup(size, CLBYTES); 135 else 136 allocsize = 1 << indx; 137 npg = clrnd(btoc(allocsize)); 138 va = (caddr_t) kmem_malloc(kmem_map, (vm_size_t)ctob(npg), 139 !(flags & M_NOWAIT)); 140 if (va == NULL) { 141 splx(s); 142 return ((void *) NULL); 143 } 144 #ifdef KMEMSTATS 145 kbp->kb_total += kbp->kb_elmpercl; 146 #endif 147 kup = btokup(va); 148 kup->ku_indx = indx; 149 if (allocsize > MAXALLOCSAVE) { 150 if (npg > 65535) 151 panic("malloc: allocation too large"); 152 kup->ku_pagecnt = npg; 153 #ifdef KMEMSTATS 154 ksp->ks_memuse += allocsize; 155 #endif 156 goto out; 157 } 158 #ifdef KMEMSTATS 159 kup->ku_freecnt = kbp->kb_elmpercl; 160 kbp->kb_totalfree += kbp->kb_elmpercl; 161 #endif 162 /* 163 * Just in case we blocked while allocating memory, 164 * and someone else also allocated memory for this 165 * bucket, don't assume the list is still empty. 166 */ 167 savedlist = kbp->kb_next; 168 kbp->kb_next = cp = va + (npg * NBPG) - allocsize; 169 for (;;) { 170 freep = (struct freelist *)cp; 171 #ifdef DIAGNOSTIC 172 /* 173 * Copy in known text to detect modification 174 * after freeing. 175 */ 176 end = (long *)&cp[copysize]; 177 for (lp = (long *)cp; lp < end; lp++) 178 *lp = WEIRD_ADDR; 179 freep->type = M_FREE; 180 #endif /* DIAGNOSTIC */ 181 if (cp <= va) 182 break; 183 cp -= allocsize; 184 freep->next = cp; 185 } 186 freep->next = savedlist; 187 if (kbp->kb_last == NULL) 188 kbp->kb_last = (caddr_t)freep; 189 } 190 va = kbp->kb_next; 191 kbp->kb_next = ((struct freelist *)va)->next; 192 #ifdef DIAGNOSTIC 193 freep = (struct freelist *)va; 194 savedtype = (unsigned)freep->type < M_LAST ? 195 memname[freep->type] : "???"; 196 if (kbp->kb_next && 197 !kernacc(kbp->kb_next, sizeof(struct freelist), 0)) { 198 printf("%s of object 0x%x size %d %s %s (invalid addr 0x%x)\n", 199 "Data modified on freelist: word 2.5", va, size, 200 "previous type", savedtype, kbp->kb_next); 201 kbp->kb_next = NULL; 202 } 203 #if BYTE_ORDER == BIG_ENDIAN 204 freep->type = WEIRD_ADDR >> 16; 205 #endif 206 #if BYTE_ORDER == LITTLE_ENDIAN 207 freep->type = (short)WEIRD_ADDR; 208 #endif 209 if (((long)(&freep->next)) & 0x2) 210 freep->next = (caddr_t)((WEIRD_ADDR >> 16)|(WEIRD_ADDR << 16)); 211 else 212 freep->next = (caddr_t)WEIRD_ADDR; 213 end = (long *)&va[copysize]; 214 for (lp = (long *)va; lp < end; lp++) { 215 if (*lp == WEIRD_ADDR) 216 continue; 217 printf("%s %d of object 0x%x size %d %s %s (0x%x != 0x%x)\n", 218 "Data modified on freelist: word", lp - (long *)va, 219 va, size, "previous type", savedtype, *lp, WEIRD_ADDR); 220 break; 221 } 222 freep->spare0 = 0; 223 #endif /* DIAGNOSTIC */ 224 #ifdef KMEMSTATS 225 kup = btokup(va); 226 if (kup->ku_indx != indx) 227 panic("malloc: wrong bucket"); 228 if (kup->ku_freecnt == 0) 229 panic("malloc: lost data"); 230 kup->ku_freecnt--; 231 kbp->kb_totalfree--; 232 ksp->ks_memuse += 1 << indx; 233 out: 234 kbp->kb_calls++; 235 ksp->ks_inuse++; 236 ksp->ks_calls++; 237 if (ksp->ks_memuse > ksp->ks_maxused) 238 ksp->ks_maxused = ksp->ks_memuse; 239 #else 240 out: 241 #endif 242 splx(s); 243 return ((void *) va); 244 } 245 246 /* 247 * Free a block of memory allocated by malloc. 248 */ 249 void 250 free(addr, type) 251 void *addr; 252 int type; 253 { 254 register struct kmembuckets *kbp; 255 register struct kmemusage *kup; 256 register struct freelist *freep; 257 long size; 258 int s; 259 #ifdef DIAGNOSTIC 260 caddr_t cp; 261 long *end, *lp, alloc, copysize; 262 #endif 263 #ifdef KMEMSTATS 264 register struct kmemstats *ksp = &kmemstats[type]; 265 #endif 266 267 kup = btokup(addr); 268 size = 1 << kup->ku_indx; 269 kbp = &bucket[kup->ku_indx]; 270 s = splimp(); 271 #ifdef DIAGNOSTIC 272 /* 273 * Check for returns of data that do not point to the 274 * beginning of the allocation. 275 */ 276 if (size > NBPG * CLSIZE) 277 alloc = addrmask[BUCKETINDX(NBPG * CLSIZE)]; 278 else 279 alloc = addrmask[kup->ku_indx]; 280 if (((u_long)addr & alloc) != 0) 281 panic("free: unaligned addr 0x%x, size %d, type %s, mask %d\n", 282 addr, size, memname[type], alloc); 283 #endif /* DIAGNOSTIC */ 284 if (size > MAXALLOCSAVE) { 285 kmem_free(kmem_map, (vm_offset_t)addr, ctob(kup->ku_pagecnt)); 286 #ifdef KMEMSTATS 287 size = kup->ku_pagecnt << PGSHIFT; 288 ksp->ks_memuse -= size; 289 kup->ku_indx = 0; 290 kup->ku_pagecnt = 0; 291 if (ksp->ks_memuse + size >= ksp->ks_limit && 292 ksp->ks_memuse < ksp->ks_limit) 293 wakeup((caddr_t)ksp); 294 ksp->ks_inuse--; 295 kbp->kb_total -= 1; 296 #endif 297 splx(s); 298 return; 299 } 300 freep = (struct freelist *)addr; 301 #ifdef DIAGNOSTIC 302 /* 303 * Check for multiple frees. Use a quick check to see if 304 * it looks free before laboriously searching the freelist. 305 */ 306 if (freep->spare0 == WEIRD_ADDR) { 307 for (cp = kbp->kb_next; cp; cp = *(caddr_t *)cp) { 308 if (addr != cp) 309 continue; 310 printf("multiply freed item 0x%x\n", addr); 311 panic("free: duplicated free"); 312 } 313 } 314 /* 315 * Copy in known text to detect modification after freeing 316 * and to make it look free. Also, save the type being freed 317 * so we can list likely culprit if modification is detected 318 * when the object is reallocated. 319 */ 320 copysize = size < MAX_COPY ? size : MAX_COPY; 321 end = (long *)&((caddr_t)addr)[copysize]; 322 for (lp = (long *)addr; lp < end; lp++) 323 *lp = WEIRD_ADDR; 324 freep->type = type; 325 #endif /* DIAGNOSTIC */ 326 #ifdef KMEMSTATS 327 kup->ku_freecnt++; 328 if (kup->ku_freecnt >= kbp->kb_elmpercl) 329 if (kup->ku_freecnt > kbp->kb_elmpercl) 330 panic("free: multiple frees"); 331 else if (kbp->kb_totalfree > kbp->kb_highwat) 332 kbp->kb_couldfree++; 333 kbp->kb_totalfree++; 334 ksp->ks_memuse -= size; 335 if (ksp->ks_memuse + size >= ksp->ks_limit && 336 ksp->ks_memuse < ksp->ks_limit) 337 wakeup((caddr_t)ksp); 338 ksp->ks_inuse--; 339 #endif 340 if (kbp->kb_next == NULL) 341 kbp->kb_next = addr; 342 else 343 ((struct freelist *)kbp->kb_last)->next = addr; 344 freep->next = NULL; 345 kbp->kb_last = addr; 346 splx(s); 347 } 348 349 /* 350 * Initialize the kernel memory allocator 351 */ 352 kmeminit() 353 { 354 register long indx; 355 int npg; 356 357 #if ((MAXALLOCSAVE & (MAXALLOCSAVE - 1)) != 0) 358 ERROR!_kmeminit:_MAXALLOCSAVE_not_power_of_2 359 #endif 360 #if (MAXALLOCSAVE > MINALLOCSIZE * 32768) 361 ERROR!_kmeminit:_MAXALLOCSAVE_too_big 362 #endif 363 #if (MAXALLOCSAVE < CLBYTES) 364 ERROR!_kmeminit:_MAXALLOCSAVE_too_small 365 #endif 366 npg = VM_KMEM_SIZE/ NBPG; 367 kmemusage = (struct kmemusage *) kmem_alloc(kernel_map, 368 (vm_size_t)(npg * sizeof(struct kmemusage))); 369 kmem_map = kmem_suballoc(kernel_map, (vm_offset_t *)&kmembase, 370 (vm_offset_t *)&kmemlimit, (vm_size_t)(npg * NBPG), FALSE); 371 #ifdef KMEMSTATS 372 for (indx = 0; indx < MINBUCKET + 16; indx++) { 373 if (1 << indx >= CLBYTES) 374 bucket[indx].kb_elmpercl = 1; 375 else 376 bucket[indx].kb_elmpercl = CLBYTES / (1 << indx); 377 bucket[indx].kb_highwat = 5 * bucket[indx].kb_elmpercl; 378 } 379 for (indx = 0; indx < M_LAST; indx++) 380 kmemstats[indx].ks_limit = npg * NBPG * 6 / 10; 381 #endif 382 } 383
Indexes created Tue Sep 23 07:09:52 GMT 2025