1 /* 2 * Copyright (c) 1987, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 * 7 * @(#)kern_malloc.c 8.3 (Berkeley) 01/04/94 8 */ 9 10 #include <sys/param.h> 11 #include <sys/proc.h> 12 #include <sys/map.h> 13 #include <sys/kernel.h> 14 #include <sys/malloc.h> 15 16 #include <vm/vm.h> 17 #include <vm/vm_kern.h> 18 19 struct kmembuckets bucket[MINBUCKET + 16]; 20 struct kmemstats kmemstats[M_LAST]; 21 struct kmemusage *kmemusage; 22 char *kmembase, *kmemlimit; 23 char *memname[] = INITKMEMNAMES; 24 25 #ifdef DIAGNOSTIC 26 /* 27 * This structure provides a set of masks to catch unaligned frees. 28 */ 29 long addrmask[] = { 0, 30 0x00000001, 0x00000003, 0x00000007, 0x0000000f, 31 0x0000001f, 0x0000003f, 0x0000007f, 0x000000ff, 32 0x000001ff, 0x000003ff, 0x000007ff, 0x00000fff, 33 0x00001fff, 0x00003fff, 0x00007fff, 0x0000ffff, 34 }; 35 36 /* 37 * The WEIRD_ADDR is used as known text to copy into free objects so 38 * that modifications after frees can be detected. 39 */ 40 #define WEIRD_ADDR 0xdeadbeef 41 #define MAX_COPY 32 42 43 /* 44 * Normally the first word of the structure is used to hold the list 45 * pointer for free objects. However, when running with diagnostics, 46 * we use the third and fourth fields, so as to catch modifications 47 * in the most commonly trashed first two words. 48 */ 49 struct freelist { 50 long spare0; 51 short type; 52 long spare1; 53 caddr_t next; 54 }; 55 #else /* !DIAGNOSTIC */ 56 struct freelist { 57 caddr_t next; 58 }; 59 #endif /* DIAGNOSTIC */ 60 61 /* 62 * Allocate a block of memory 63 */ 64 void * 65 malloc(size, type, flags) 66 unsigned long size; 67 int type, flags; 68 { 69 register struct kmembuckets *kbp; 70 register struct kmemusage *kup; 71 register struct freelist *freep; 72 long indx, npg, allocsize; 73 int s; 74 caddr_t va, cp, savedlist; 75 #ifdef DIAGNOSTIC 76 long *end, *lp; 77 int copysize; 78 char *savedtype; 79 #endif 80 #ifdef KMEMSTATS 81 register struct kmemstats *ksp = &kmemstats[type]; 82 83 if (((unsigned long)type) > M_LAST) 84 panic("malloc - bogus type"); 85 #endif 86 indx = BUCKETINDX(size); 87 kbp = &bucket[indx]; 88 s = splimp(); 89 #ifdef KMEMSTATS 90 while (ksp->ks_memuse >= ksp->ks_limit) { 91 if (flags & M_NOWAIT) { 92 splx(s); 93 return ((void *) NULL); 94 } 95 if (ksp->ks_limblocks < 65535) 96 ksp->ks_limblocks++; 97 tsleep((caddr_t)ksp, PSWP+2, memname[type], 0); 98 } 99 ksp->ks_size |= 1 << indx; 100 #endif 101 #ifdef DIAGNOSTIC 102 copysize = 1 << indx < MAX_COPY ? 1 << indx : MAX_COPY; 103 #endif 104 if (kbp->kb_next == NULL) { 105 kbp->kb_last = NULL; 106 if (size > MAXALLOCSAVE) 107 allocsize = roundup(size, CLBYTES); 108 else 109 allocsize = 1 << indx; 110 npg = clrnd(btoc(allocsize)); 111 va = (caddr_t) kmem_malloc(kmem_map, (vm_size_t)ctob(npg), 112 !(flags & M_NOWAIT)); 113 if (va == NULL) { 114 splx(s); 115 return ((void *) NULL); 116 } 117 #ifdef KMEMSTATS 118 kbp->kb_total += kbp->kb_elmpercl; 119 #endif 120 kup = btokup(va); 121 kup->ku_indx = indx; 122 if (allocsize > MAXALLOCSAVE) { 123 if (npg > 65535) 124 panic("malloc: allocation too large"); 125 kup->ku_pagecnt = npg; 126 #ifdef KMEMSTATS 127 ksp->ks_memuse += allocsize; 128 #endif 129 goto out; 130 } 131 #ifdef KMEMSTATS 132 kup->ku_freecnt = kbp->kb_elmpercl; 133 kbp->kb_totalfree += kbp->kb_elmpercl; 134 #endif 135 /* 136 * Just in case we blocked while allocating memory, 137 * and someone else also allocated memory for this 138 * bucket, don't assume the list is still empty. 139 */ 140 savedlist = kbp->kb_next; 141 kbp->kb_next = cp = va + (npg * NBPG) - allocsize; 142 for (;;) { 143 freep = (struct freelist *)cp; 144 #ifdef DIAGNOSTIC 145 /* 146 * Copy in known text to detect modification 147 * after freeing. 148 */ 149 end = (long *)&cp[copysize]; 150 for (lp = (long *)cp; lp < end; lp++) 151 *lp = WEIRD_ADDR; 152 freep->type = M_FREE; 153 #endif /* DIAGNOSTIC */ 154 if (cp <= va) 155 break; 156 cp -= allocsize; 157 freep->next = cp; 158 } 159 freep->next = savedlist; 160 if (kbp->kb_last == NULL) 161 kbp->kb_last = (caddr_t)freep; 162 } 163 va = kbp->kb_next; 164 kbp->kb_next = ((struct freelist *)va)->next; 165 #ifdef DIAGNOSTIC 166 freep = (struct freelist *)va; 167 savedtype = (unsigned)freep->type < M_LAST ? 168 memname[freep->type] : "???"; 169 if (kbp->kb_next && 170 !kernacc(kbp->kb_next, sizeof(struct freelist), 0)) { 171 printf("%s of object 0x%x size %d %s %s (invalid addr 0x%x)\n", 172 "Data modified on freelist: word 2.5", va, size, 173 "previous type", savedtype, kbp->kb_next); 174 kbp->kb_next = NULL; 175 } 176 #if BYTE_ORDER == BIG_ENDIAN 177 freep->type = WEIRD_ADDR >> 16; 178 #endif 179 #if BYTE_ORDER == LITTLE_ENDIAN 180 freep->type = (short)WEIRD_ADDR; 181 #endif 182 if (((long)(&freep->next)) & 0x2) 183 freep->next = (caddr_t)((WEIRD_ADDR >> 16)|(WEIRD_ADDR << 16)); 184 else 185 freep->next = (caddr_t)WEIRD_ADDR; 186 end = (long *)&va[copysize]; 187 for (lp = (long *)va; lp < end; lp++) { 188 if (*lp == WEIRD_ADDR) 189 continue; 190 printf("%s %d of object 0x%x size %d %s %s (0x%x != 0x%x)\n", 191 "Data modified on freelist: word", lp - (long *)va, 192 va, size, "previous type", savedtype, *lp, WEIRD_ADDR); 193 break; 194 } 195 freep->spare0 = 0; 196 #endif /* DIAGNOSTIC */ 197 #ifdef KMEMSTATS 198 kup = btokup(va); 199 if (kup->ku_indx != indx) 200 panic("malloc: wrong bucket"); 201 if (kup->ku_freecnt == 0) 202 panic("malloc: lost data"); 203 kup->ku_freecnt--; 204 kbp->kb_totalfree--; 205 ksp->ks_memuse += 1 << indx; 206 out: 207 kbp->kb_calls++; 208 ksp->ks_inuse++; 209 ksp->ks_calls++; 210 if (ksp->ks_memuse > ksp->ks_maxused) 211 ksp->ks_maxused = ksp->ks_memuse; 212 #else 213 out: 214 #endif 215 splx(s); 216 return ((void *) va); 217 } 218 219 /* 220 * Free a block of memory allocated by malloc. 221 */ 222 void 223 free(addr, type) 224 void *addr; 225 int type; 226 { 227 register struct kmembuckets *kbp; 228 register struct kmemusage *kup; 229 register struct freelist *freep; 230 long size; 231 int s; 232 #ifdef DIAGNOSTIC 233 caddr_t cp; 234 long *end, *lp, alloc, copysize; 235 #endif 236 #ifdef KMEMSTATS 237 register struct kmemstats *ksp = &kmemstats[type]; 238 #endif 239 240 kup = btokup(addr); 241 size = 1 << kup->ku_indx; 242 kbp = &bucket[kup->ku_indx]; 243 s = splimp(); 244 #ifdef DIAGNOSTIC 245 /* 246 * Check for returns of data that do not point to the 247 * beginning of the allocation. 248 */ 249 if (size > NBPG * CLSIZE) 250 alloc = addrmask[BUCKETINDX(NBPG * CLSIZE)]; 251 else 252 alloc = addrmask[kup->ku_indx]; 253 if (((u_long)addr & alloc) != 0) 254 panic("free: unaligned addr 0x%x, size %d, type %s, mask %d\n", 255 addr, size, memname[type], alloc); 256 #endif /* DIAGNOSTIC */ 257 if (size > MAXALLOCSAVE) { 258 kmem_free(kmem_map, (vm_offset_t)addr, ctob(kup->ku_pagecnt)); 259 #ifdef KMEMSTATS 260 size = kup->ku_pagecnt << PGSHIFT; 261 ksp->ks_memuse -= size; 262 kup->ku_indx = 0; 263 kup->ku_pagecnt = 0; 264 if (ksp->ks_memuse + size >= ksp->ks_limit && 265 ksp->ks_memuse < ksp->ks_limit) 266 wakeup((caddr_t)ksp); 267 ksp->ks_inuse--; 268 kbp->kb_total -= 1; 269 #endif 270 splx(s); 271 return; 272 } 273 freep = (struct freelist *)addr; 274 #ifdef DIAGNOSTIC 275 /* 276 * Check for multiple frees. Use a quick check to see if 277 * it looks free before laboriously searching the freelist. 278 */ 279 if (freep->spare0 == WEIRD_ADDR) { 280 for (cp = kbp->kb_next; cp; cp = *(caddr_t *)cp) { 281 if (addr != cp) 282 continue; 283 printf("multiply freed item 0x%x\n", addr); 284 panic("free: duplicated free"); 285 } 286 } 287 /* 288 * Copy in known text to detect modification after freeing 289 * and to make it look free. Also, save the type being freed 290 * so we can list likely culprit if modification is detected 291 * when the object is reallocated. 292 */ 293 copysize = size < MAX_COPY ? size : MAX_COPY; 294 end = (long *)&((caddr_t)addr)[copysize]; 295 for (lp = (long *)addr; lp < end; lp++) 296 *lp = WEIRD_ADDR; 297 freep->type = type; 298 #endif /* DIAGNOSTIC */ 299 #ifdef KMEMSTATS 300 kup->ku_freecnt++; 301 if (kup->ku_freecnt >= kbp->kb_elmpercl) 302 if (kup->ku_freecnt > kbp->kb_elmpercl) 303 panic("free: multiple frees"); 304 else if (kbp->kb_totalfree > kbp->kb_highwat) 305 kbp->kb_couldfree++; 306 kbp->kb_totalfree++; 307 ksp->ks_memuse -= size; 308 if (ksp->ks_memuse + size >= ksp->ks_limit && 309 ksp->ks_memuse < ksp->ks_limit) 310 wakeup((caddr_t)ksp); 311 ksp->ks_inuse--; 312 #endif 313 if (kbp->kb_next == NULL) 314 kbp->kb_next = addr; 315 else 316 ((struct freelist *)kbp->kb_last)->next = addr; 317 freep->next = NULL; 318 kbp->kb_last = addr; 319 splx(s); 320 } 321 322 /* 323 * Initialize the kernel memory allocator 324 */ 325 kmeminit() 326 { 327 register long indx; 328 int npg; 329 330 #if ((MAXALLOCSAVE & (MAXALLOCSAVE - 1)) != 0) 331 ERROR!_kmeminit:_MAXALLOCSAVE_not_power_of_2 332 #endif 333 #if (MAXALLOCSAVE > MINALLOCSIZE * 32768) 334 ERROR!_kmeminit:_MAXALLOCSAVE_too_big 335 #endif 336 #if (MAXALLOCSAVE < CLBYTES) 337 ERROR!_kmeminit:_MAXALLOCSAVE_too_small 338 #endif 339 npg = VM_KMEM_SIZE/ NBPG; 340 kmemusage = (struct kmemusage *) kmem_alloc(kernel_map, 341 (vm_size_t)(npg * sizeof(struct kmemusage))); 342 kmem_map = kmem_suballoc(kernel_map, (vm_offset_t *)&kmembase, 343 (vm_offset_t *)&kmemlimit, (vm_size_t)(npg * NBPG), FALSE); 344 #ifdef KMEMSTATS 345 for (indx = 0; indx < MINBUCKET + 16; indx++) { 346 if (1 << indx >= CLBYTES) 347 bucket[indx].kb_elmpercl = 1; 348 else 349 bucket[indx].kb_elmpercl = CLBYTES / (1 << indx); 350 bucket[indx].kb_highwat = 5 * bucket[indx].kb_elmpercl; 351 } 352 for (indx = 0; indx < M_LAST; indx++) 353 kmemstats[indx].ks_limit = npg * NBPG * 6 / 10; 354 #endif 355 } 356