kern_malloc.c revision 1.10
1 /* $NetBSD: kern_malloc.c,v 1.10 1995/03/19 23:44:44 mycroft 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 first word of the structure is used to hold the list 73 * pointer for free objects. However, when running with diagnostics, 74 * we use the third and fourth fields, so as to catch modifications 75 * in the most commonly trashed first two words. 76 */ 77 struct freelist { 78 long spare0; 79 short type; 80 long spare1; 81 caddr_t next; 82 }; 83 #else /* !DIAGNOSTIC */ 84 struct freelist { 85 caddr_t next; 86 }; 87 #endif /* DIAGNOSTIC */ 88 89 /* 90 * Allocate a block of memory 91 */ 92 void * 93 malloc(size, type, flags) 94 unsigned long size; 95 int type, flags; 96 { 97 register struct kmembuckets *kbp; 98 register struct kmemusage *kup; 99 register struct freelist *freep; 100 long indx, npg, allocsize; 101 int s; 102 caddr_t va, cp, savedlist; 103 #ifdef DIAGNOSTIC 104 long *end, *lp; 105 int copysize; 106 char *savedtype; 107 #endif 108 #ifdef KMEMSTATS 109 register struct kmemstats *ksp = &kmemstats[type]; 110 111 if (((unsigned long)type) > M_LAST) 112 panic("malloc - bogus type"); 113 #endif 114 indx = BUCKETINDX(size); 115 kbp = &bucket[indx]; 116 s = splimp(); 117 #ifdef KMEMSTATS 118 while (ksp->ks_memuse >= ksp->ks_limit) { 119 if (flags & M_NOWAIT) { 120 splx(s); 121 return ((void *) NULL); 122 } 123 if (ksp->ks_limblocks < 65535) 124 ksp->ks_limblocks++; 125 tsleep((caddr_t)ksp, PSWP+2, memname[type], 0); 126 } 127 ksp->ks_size |= 1 << indx; 128 #endif 129 #ifdef DIAGNOSTIC 130 copysize = 1 << indx < MAX_COPY ? 1 << indx : MAX_COPY; 131 #endif 132 if (kbp->kb_next == NULL) { 133 kbp->kb_last = NULL; 134 if (size > MAXALLOCSAVE) 135 allocsize = roundup(size, CLBYTES); 136 else 137 allocsize = 1 << indx; 138 npg = clrnd(btoc(allocsize)); 139 va = (caddr_t) kmem_malloc(kmem_map, (vm_size_t)ctob(npg), 140 !(flags & M_NOWAIT)); 141 if (va == NULL) { 142 splx(s); 143 return ((void *) NULL); 144 } 145 #ifdef KMEMSTATS 146 kbp->kb_total += kbp->kb_elmpercl; 147 #endif 148 kup = btokup(va); 149 kup->ku_indx = indx; 150 if (allocsize > MAXALLOCSAVE) { 151 if (npg > 65535) 152 panic("malloc: allocation too large"); 153 kup->ku_pagecnt = npg; 154 #ifdef KMEMSTATS 155 ksp->ks_memuse += allocsize; 156 #endif 157 goto out; 158 } 159 #ifdef KMEMSTATS 160 kup->ku_freecnt = kbp->kb_elmpercl; 161 kbp->kb_totalfree += kbp->kb_elmpercl; 162 #endif 163 /* 164 * Just in case we blocked while allocating memory, 165 * and someone else also allocated memory for this 166 * bucket, don't assume the list is still empty. 167 */ 168 savedlist = kbp->kb_next; 169 kbp->kb_next = cp = va + (npg * NBPG) - allocsize; 170 for (;;) { 171 freep = (struct freelist *)cp; 172 #ifdef DIAGNOSTIC 173 /* 174 * Copy in known text to detect modification 175 * after freeing. 176 */ 177 end = (long *)&cp[copysize]; 178 for (lp = (long *)cp; lp < end; lp++) 179 *lp = WEIRD_ADDR; 180 freep->type = M_FREE; 181 #endif /* DIAGNOSTIC */ 182 if (cp <= va) 183 break; 184 cp -= allocsize; 185 freep->next = cp; 186 } 187 freep->next = savedlist; 188 if (kbp->kb_last == NULL) 189 kbp->kb_last = (caddr_t)freep; 190 } 191 va = kbp->kb_next; 192 kbp->kb_next = ((struct freelist *)va)->next; 193 #ifdef DIAGNOSTIC 194 freep = (struct freelist *)va; 195 savedtype = (unsigned)freep->type < M_LAST ? 196 memname[freep->type] : "???"; 197 if (kbp->kb_next && 198 !kernacc(kbp->kb_next, sizeof(struct freelist), 0)) { 199 printf("%s of object %p size %d %s %s (invalid addr %p)\n", 200 "Data modified on freelist: word 2.5", va, size, 201 "previous type", savedtype, kbp->kb_next); 202 kbp->kb_next = NULL; 203 } 204 #if BYTE_ORDER == BIG_ENDIAN 205 freep->type = WEIRD_ADDR >> 16; 206 #endif 207 #if BYTE_ORDER == LITTLE_ENDIAN 208 freep->type = (short)WEIRD_ADDR; 209 #endif 210 if (((long)(&freep->next)) & 0x2) 211 freep->next = (caddr_t)((WEIRD_ADDR >> 16)|(WEIRD_ADDR << 16)); 212 else 213 freep->next = (caddr_t)WEIRD_ADDR; 214 end = (long *)&va[copysize]; 215 for (lp = (long *)va; lp < end; lp++) { 216 if (*lp == WEIRD_ADDR) 217 continue; 218 printf("%s %d of object %p size %d %s %s (%p != %p)\n", 219 "Data modified on freelist: word", lp - (long *)va, 220 va, size, "previous type", savedtype, *lp, WEIRD_ADDR); 221 break; 222 } 223 freep->spare0 = 0; 224 #endif /* DIAGNOSTIC */ 225 #ifdef KMEMSTATS 226 kup = btokup(va); 227 if (kup->ku_indx != indx) 228 panic("malloc: wrong bucket"); 229 if (kup->ku_freecnt == 0) 230 panic("malloc: lost data"); 231 kup->ku_freecnt--; 232 kbp->kb_totalfree--; 233 ksp->ks_memuse += 1 << indx; 234 out: 235 kbp->kb_calls++; 236 ksp->ks_inuse++; 237 ksp->ks_calls++; 238 if (ksp->ks_memuse > ksp->ks_maxused) 239 ksp->ks_maxused = ksp->ks_memuse; 240 #else 241 out: 242 #endif 243 splx(s); 244 return ((void *) va); 245 } 246 247 /* 248 * Free a block of memory allocated by malloc. 249 */ 250 void 251 free(addr, type) 252 void *addr; 253 int type; 254 { 255 register struct kmembuckets *kbp; 256 register struct kmemusage *kup; 257 register struct freelist *freep; 258 long size; 259 int s; 260 #ifdef DIAGNOSTIC 261 caddr_t cp; 262 long *end, *lp, alloc, copysize; 263 #endif 264 #ifdef KMEMSTATS 265 register struct kmemstats *ksp = &kmemstats[type]; 266 #endif 267 268 kup = btokup(addr); 269 size = 1 << kup->ku_indx; 270 kbp = &bucket[kup->ku_indx]; 271 s = splimp(); 272 #ifdef DIAGNOSTIC 273 /* 274 * Check for returns of data that do not point to the 275 * beginning of the allocation. 276 */ 277 if (size > NBPG * CLSIZE) 278 alloc = addrmask[BUCKETINDX(NBPG * CLSIZE)]; 279 else 280 alloc = addrmask[kup->ku_indx]; 281 if (((u_long)addr & alloc) != 0) 282 panic("free: unaligned addr 0x%x, size %d, type %s, mask %d\n", 283 addr, size, memname[type], alloc); 284 #endif /* DIAGNOSTIC */ 285 if (size > MAXALLOCSAVE) { 286 kmem_free(kmem_map, (vm_offset_t)addr, ctob(kup->ku_pagecnt)); 287 #ifdef KMEMSTATS 288 size = kup->ku_pagecnt << PGSHIFT; 289 ksp->ks_memuse -= size; 290 kup->ku_indx = 0; 291 kup->ku_pagecnt = 0; 292 if (ksp->ks_memuse + size >= ksp->ks_limit && 293 ksp->ks_memuse < ksp->ks_limit) 294 wakeup((caddr_t)ksp); 295 ksp->ks_inuse--; 296 kbp->kb_total -= 1; 297 #endif 298 splx(s); 299 return; 300 } 301 freep = (struct freelist *)addr; 302 #ifdef DIAGNOSTIC 303 /* 304 * Check for multiple frees. Use a quick check to see if 305 * it looks free before laboriously searching the freelist. 306 */ 307 if (freep->spare0 == WEIRD_ADDR) { 308 for (cp = kbp->kb_next; cp; cp = *(caddr_t *)cp) { 309 if (addr != cp) 310 continue; 311 printf("multiply freed item %p\n", addr); 312 panic("free: duplicated free"); 313 } 314 } 315 /* 316 * Copy in known text to detect modification after freeing 317 * and to make it look free. Also, save the type being freed 318 * so we can list likely culprit if modification is detected 319 * when the object is reallocated. 320 */ 321 copysize = size < MAX_COPY ? size : MAX_COPY; 322 end = (long *)&((caddr_t)addr)[copysize]; 323 for (lp = (long *)addr; lp < end; lp++) 324 *lp = WEIRD_ADDR; 325 freep->type = type; 326 #endif /* DIAGNOSTIC */ 327 #ifdef KMEMSTATS 328 kup->ku_freecnt++; 329 if (kup->ku_freecnt >= kbp->kb_elmpercl) 330 if (kup->ku_freecnt > kbp->kb_elmpercl) 331 panic("free: multiple frees"); 332 else if (kbp->kb_totalfree > kbp->kb_highwat) 333 kbp->kb_couldfree++; 334 kbp->kb_totalfree++; 335 ksp->ks_memuse -= size; 336 if (ksp->ks_memuse + size >= ksp->ks_limit && 337 ksp->ks_memuse < ksp->ks_limit) 338 wakeup((caddr_t)ksp); 339 ksp->ks_inuse--; 340 #endif 341 if (kbp->kb_next == NULL) 342 kbp->kb_next = addr; 343 else 344 ((struct freelist *)kbp->kb_last)->next = addr; 345 freep->next = NULL; 346 kbp->kb_last = addr; 347 splx(s); 348 } 349 350 /* 351 * Initialize the kernel memory allocator 352 */ 353 kmeminit() 354 { 355 register long indx; 356 int npg; 357 358 #if ((MAXALLOCSAVE & (MAXALLOCSAVE - 1)) != 0) 359 ERROR!_kmeminit:_MAXALLOCSAVE_not_power_of_2 360 #endif 361 #if (MAXALLOCSAVE > MINALLOCSIZE * 32768) 362 ERROR!_kmeminit:_MAXALLOCSAVE_too_big 363 #endif 364 #if (MAXALLOCSAVE < CLBYTES) 365 ERROR!_kmeminit:_MAXALLOCSAVE_too_small 366 #endif 367 npg = VM_KMEM_SIZE/ NBPG; 368 kmemusage = (struct kmemusage *) kmem_alloc(kernel_map, 369 (vm_size_t)(npg * sizeof(struct kmemusage))); 370 kmem_map = kmem_suballoc(kernel_map, (vm_offset_t *)&kmembase, 371 (vm_offset_t *)&kmemlimit, (vm_size_t)(npg * NBPG), FALSE); 372 #ifdef KMEMSTATS 373 for (indx = 0; indx < MINBUCKET + 16; indx++) { 374 if (1 << indx >= CLBYTES) 375 bucket[indx].kb_elmpercl = 1; 376 else 377 bucket[indx].kb_elmpercl = CLBYTES / (1 << indx); 378 bucket[indx].kb_highwat = 5 * bucket[indx].kb_elmpercl; 379 } 380 for (indx = 0; indx < M_LAST; indx++) 381 kmemstats[indx].ks_limit = npg * NBPG * 6 / 10; 382 #endif 383 } 384
Indexes created Sat Sep 20 22:09:52 GMT 2025