1 /* 2 * Copyright (c) 1987, 1991 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 * 7 * @(#)kern_malloc.c 7.35 (Berkeley) 10/11/92 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, alloc, 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 #endif 100 #ifdef DIAGNOSTIC 101 copysize = 1 << indx < MAX_COPY ? 1 << indx : MAX_COPY; 102 #endif 103 if (kbp->kb_next == NULL) { 104 kbp->kb_last = NULL; 105 if (size > MAXALLOCSAVE) 106 allocsize = roundup(size, CLBYTES); 107 else 108 allocsize = 1 << indx; 109 npg = clrnd(btoc(allocsize)); 110 va = (caddr_t) kmem_malloc(kmem_map, (vm_size_t)ctob(npg), 111 !(flags & M_NOWAIT)); 112 if (va == NULL) { 113 splx(s); 114 return ((void *) NULL); 115 } 116 #ifdef KMEMSTATS 117 kbp->kb_total += kbp->kb_elmpercl; 118 #endif 119 kup = btokup(va); 120 kup->ku_indx = indx; 121 if (allocsize > MAXALLOCSAVE) { 122 if (npg > 65535) 123 panic("malloc: allocation too large"); 124 kup->ku_pagecnt = npg; 125 #ifdef KMEMSTATS 126 ksp->ks_memuse += allocsize; 127 #endif 128 goto out; 129 } 130 #ifdef KMEMSTATS 131 kup->ku_freecnt = kbp->kb_elmpercl; 132 kbp->kb_totalfree += kbp->kb_elmpercl; 133 #endif 134 /* 135 * Just in case we blocked while allocating memory, 136 * and someone else also allocated memory for this 137 * bucket, don't assume the list is still empty. 138 */ 139 savedlist = kbp->kb_next; 140 kbp->kb_next = cp = va + (npg * NBPG) - allocsize; 141 for (;;) { 142 freep = (struct freelist *)cp; 143 #ifdef DIAGNOSTIC 144 /* 145 * Copy in known text to detect modification 146 * after freeing. 147 */ 148 end = (long *)&cp[copysize]; 149 for (lp = (long *)cp; lp < end; lp++) 150 *lp = WEIRD_ADDR; 151 freep->type = M_FREE; 152 #endif /* DIAGNOSTIC */ 153 if (cp <= va) 154 break; 155 cp -= allocsize; 156 freep->next = cp; 157 } 158 freep->next = savedlist; 159 if (kbp->kb_last == NULL) 160 kbp->kb_last = (caddr_t)freep; 161 } 162 va = kbp->kb_next; 163 kbp->kb_next = ((struct freelist *)va)->next; 164 #ifdef DIAGNOSTIC 165 freep = (struct freelist *)va; 166 savedtype = (unsigned)freep->type < M_LAST ? 167 memname[freep->type] : "???"; 168 #if BYTE_ORDER == BIG_ENDIAN 169 freep->type = WEIRD_ADDR >> 16; 170 #endif 171 #if BYTE_ORDER == LITTLE_ENDIAN 172 freep->type = WEIRD_ADDR; 173 #endif 174 if (((long)(&freep->next)) & 0x2) 175 freep->next = (caddr_t)((WEIRD_ADDR >> 16)|(WEIRD_ADDR << 16)); 176 else 177 freep->next = (caddr_t)WEIRD_ADDR; 178 end = (long *)&va[copysize]; 179 for (lp = (long *)va; lp < end; lp++) { 180 if (*lp == WEIRD_ADDR) 181 continue; 182 printf("%s %d of object 0x%x size %d %s %s (0x%x != 0x%x)\n", 183 "Data modified on freelist: word", lp - (long *)va, 184 va, size, "previous type", savedtype, *lp, WEIRD_ADDR); 185 break; 186 } 187 freep->spare0 = 0; 188 #endif /* DIAGNOSTIC */ 189 #ifdef KMEMSTATS 190 kup = btokup(va); 191 if (kup->ku_indx != indx) 192 panic("malloc: wrong bucket"); 193 if (kup->ku_freecnt == 0) 194 panic("malloc: lost data"); 195 kup->ku_freecnt--; 196 kbp->kb_totalfree--; 197 ksp->ks_memuse += 1 << indx; 198 out: 199 kbp->kb_calls++; 200 ksp->ks_inuse++; 201 ksp->ks_calls++; 202 if (ksp->ks_memuse > ksp->ks_maxused) 203 ksp->ks_maxused = ksp->ks_memuse; 204 #else 205 out: 206 #endif 207 splx(s); 208 return ((void *) va); 209 } 210 211 /* 212 * Free a block of memory allocated by malloc. 213 */ 214 void 215 free(addr, type) 216 void *addr; 217 int type; 218 { 219 register struct kmembuckets *kbp; 220 register struct kmemusage *kup; 221 register struct freelist *freep; 222 long size; 223 int s; 224 #ifdef DIAGNOSTIC 225 caddr_t cp; 226 long *end, *lp, alloc, copysize; 227 #endif 228 #ifdef KMEMSTATS 229 register struct kmemstats *ksp = &kmemstats[type]; 230 #endif 231 232 kup = btokup(addr); 233 size = 1 << kup->ku_indx; 234 kbp = &bucket[kup->ku_indx]; 235 s = splimp(); 236 #ifdef DIAGNOSTIC 237 /* 238 * Check for returns of data that do not point to the 239 * beginning of the allocation. 240 */ 241 if (size > NBPG * CLSIZE) 242 alloc = addrmask[BUCKETINDX(NBPG * CLSIZE)]; 243 else 244 alloc = addrmask[kup->ku_indx]; 245 if (((u_long)addr & alloc) != 0) 246 panic("free: unaligned addr 0x%x, size %d, type %s, mask %d\n", 247 addr, size, memname[type], alloc); 248 #endif /* DIAGNOSTIC */ 249 if (size > MAXALLOCSAVE) { 250 kmem_free(kmem_map, (vm_offset_t)addr, ctob(kup->ku_pagecnt)); 251 #ifdef KMEMSTATS 252 size = kup->ku_pagecnt << PGSHIFT; 253 ksp->ks_memuse -= size; 254 kup->ku_indx = 0; 255 kup->ku_pagecnt = 0; 256 if (ksp->ks_memuse + size >= ksp->ks_limit && 257 ksp->ks_memuse < ksp->ks_limit) 258 wakeup((caddr_t)ksp); 259 ksp->ks_inuse--; 260 kbp->kb_total -= 1; 261 #endif 262 splx(s); 263 return; 264 } 265 freep = (struct freelist *)addr; 266 #ifdef DIAGNOSTIC 267 /* 268 * Check for multiple frees. Use a quick check to see if 269 * it looks free before laboriously searching the freelist. 270 */ 271 if (freep->spare0 == WEIRD_ADDR) { 272 for (cp = kbp->kb_next; cp; cp = *(caddr_t *)cp) { 273 if (addr != cp) 274 continue; 275 printf("multiply freed item 0x%x\n", addr); 276 panic("free: duplicated free"); 277 } 278 } 279 /* 280 * Copy in known text to detect modification after freeing 281 * and to make it look free. Also, save the type being freed 282 * so we can list likely culprit if modification is detected 283 * when the object is reallocated. 284 */ 285 copysize = size < MAX_COPY ? size : MAX_COPY; 286 end = (long *)&((caddr_t)addr)[copysize]; 287 for (lp = (long *)addr; lp < end; lp++) 288 *lp = WEIRD_ADDR; 289 freep->type = type; 290 #endif /* DIAGNOSTIC */ 291 #ifdef KMEMSTATS 292 kup->ku_freecnt++; 293 if (kup->ku_freecnt >= kbp->kb_elmpercl) 294 if (kup->ku_freecnt > kbp->kb_elmpercl) 295 panic("free: multiple frees"); 296 else if (kbp->kb_totalfree > kbp->kb_highwat) 297 kbp->kb_couldfree++; 298 kbp->kb_totalfree++; 299 ksp->ks_memuse -= size; 300 if (ksp->ks_memuse + size >= ksp->ks_limit && 301 ksp->ks_memuse < ksp->ks_limit) 302 wakeup((caddr_t)ksp); 303 ksp->ks_inuse--; 304 #endif 305 if (kbp->kb_next == NULL) 306 kbp->kb_next = addr; 307 else 308 ((struct freelist *)kbp->kb_last)->next = addr; 309 freep->next = NULL; 310 kbp->kb_last = addr; 311 splx(s); 312 } 313 314 /* 315 * Initialize the kernel memory allocator 316 */ 317 kmeminit() 318 { 319 register long indx; 320 int npg; 321 322 #if ((MAXALLOCSAVE & (MAXALLOCSAVE - 1)) != 0) 323 ERROR!_kmeminit:_MAXALLOCSAVE_not_power_of_2 324 #endif 325 #if (MAXALLOCSAVE > MINALLOCSIZE * 32768) 326 ERROR!_kmeminit:_MAXALLOCSAVE_too_big 327 #endif 328 #if (MAXALLOCSAVE < CLBYTES) 329 ERROR!_kmeminit:_MAXALLOCSAVE_too_small 330 #endif 331 npg = VM_KMEM_SIZE/ NBPG; 332 kmemusage = (struct kmemusage *) kmem_alloc(kernel_map, 333 (vm_size_t)(npg * sizeof(struct kmemusage))); 334 kmem_map = kmem_suballoc(kernel_map, (vm_offset_t *)&kmembase, 335 (vm_offset_t *)&kmemlimit, (vm_size_t)(npg * NBPG), FALSE); 336 #ifdef KMEMSTATS 337 for (indx = 0; indx < MINBUCKET + 16; indx++) { 338 if (1 << indx >= CLBYTES) 339 bucket[indx].kb_elmpercl = 1; 340 else 341 bucket[indx].kb_elmpercl = CLBYTES / (1 << indx); 342 bucket[indx].kb_highwat = 5 * bucket[indx].kb_elmpercl; 343 } 344 for (indx = 0; indx < M_LAST; indx++) 345 kmemstats[indx].ks_limit = npg * NBPG * 6 / 10; 346 #endif 347 } 348