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 7.26 (Berkeley) 08/01/91 8 */ 9 10 #include "param.h" 11 #include "proc.h" 12 #include "map.h" 13 #include "kernel.h" 14 #include "malloc.h" 15 #include "vm/vm.h" 16 #include "vm/vm_kern.h" 17 18 struct kmembuckets bucket[MINBUCKET + 16]; 19 struct kmemstats kmemstats[M_LAST]; 20 struct kmemusage *kmemusage; 21 char *kmembase, *kmemlimit; 22 char *memname[] = INITKMEMNAMES; 23 24 #ifdef DIAGNOSTIC 25 /* 26 * This structure serves two purposes. 27 * The first is to provide a set of masks to catch unaligned frees. 28 * The second is to provide known text to copy into free objects so 29 * that modifications after frees can be detected. 30 */ 31 #define WEIRD_ADDR 0xdeadbeef 32 long addrmask[] = { WEIRD_ADDR, 33 0x00000001, 0x00000003, 0x00000007, 0x0000000f, 34 0x0000001f, 0x0000003f, 0x0000007f, 0x000000ff, 35 0x000001ff, 0x000003ff, 0x000007ff, 0x00000fff, 36 0x00001fff, 0x00003fff, 0x00007fff, 0x0000ffff, 37 }; 38 #endif /* DIAGNOSTIC */ 39 40 /* 41 * Allocate a block of memory 42 */ 43 void * 44 malloc(size, type, flags) 45 unsigned long size; 46 int type, flags; 47 { 48 register struct kmembuckets *kbp; 49 register struct kmemusage *kup; 50 long indx, npg, alloc, allocsize; 51 int s; 52 caddr_t va, cp, savedlist; 53 #ifdef DIAGNOSTIC 54 int i, copysize; 55 #endif 56 #ifdef KMEMSTATS 57 register struct kmemstats *ksp = &kmemstats[type]; 58 59 if (((unsigned long)type) > M_LAST) 60 panic("malloc - bogus type"); 61 #endif 62 63 indx = BUCKETINDX(size); 64 kbp = &bucket[indx]; 65 s = splimp(); 66 #ifdef KMEMSTATS 67 while (ksp->ks_memuse >= ksp->ks_limit) { 68 if (flags & M_NOWAIT) { 69 splx(s); 70 return ((void *) NULL); 71 } 72 if (ksp->ks_limblocks < 65535) 73 ksp->ks_limblocks++; 74 tsleep((caddr_t)ksp, PSWP+2, memname[type], 0); 75 } 76 #endif 77 #ifdef DIAGNOSTIC 78 copysize = 1 << indx < sizeof addrmask ? 1 << indx : sizeof addrmask; 79 #endif 80 if (kbp->kb_next == NULL) { 81 if (size > MAXALLOCSAVE) 82 allocsize = roundup(size, CLBYTES); 83 else 84 allocsize = 1 << indx; 85 npg = clrnd(btoc(allocsize)); 86 va = (caddr_t) kmem_malloc(kmem_map, (vm_size_t)ctob(npg), 87 !(flags & M_NOWAIT)); 88 if (va == NULL) { 89 splx(s); 90 return ((void *) NULL); 91 } 92 #ifdef KMEMSTATS 93 kbp->kb_total += kbp->kb_elmpercl; 94 #endif 95 kup = btokup(va); 96 kup->ku_indx = indx; 97 if (allocsize > MAXALLOCSAVE) { 98 if (npg > 65535) 99 panic("malloc: allocation too large"); 100 kup->ku_pagecnt = npg; 101 #ifdef KMEMSTATS 102 ksp->ks_memuse += allocsize; 103 #endif 104 goto out; 105 } 106 #ifdef KMEMSTATS 107 kup->ku_freecnt = kbp->kb_elmpercl; 108 kbp->kb_totalfree += kbp->kb_elmpercl; 109 #endif 110 /* 111 * Just in case we blocked while allocating memory, 112 * and someone else also allocated memory for this 113 * bucket, don't assume the list is still empty. 114 */ 115 savedlist = kbp->kb_next; 116 kbp->kb_next = va + (npg * NBPG) - allocsize; 117 for (cp = kbp->kb_next; ; cp -= allocsize) { 118 #ifdef DIAGNOSTIC 119 /* 120 * Copy in known text to detect modification 121 * after freeing. 122 */ 123 bcopy(addrmask, cp, copysize); 124 #endif /* DIAGNOSTIC */ 125 if (cp <= va) 126 break; 127 *(caddr_t *)cp = cp - allocsize; 128 } 129 *(caddr_t *)cp = savedlist; 130 } 131 va = kbp->kb_next; 132 kbp->kb_next = *(caddr_t *)va; 133 #ifdef DIAGNOSTIC 134 *(caddr_t *)va = (char *)WEIRD_ADDR; 135 if (bcmp(addrmask, va, copysize)) { 136 copysize >>= 2; 137 for (i = 0; i < copysize && addrmask[i] == ((int *)va)[i]; i++) 138 /* void */; 139 printf("Word %d %s 0x%x of size %d modified (0x%x != 0x%x)\n", 140 i, "of object", va, size, ((int *)va)[i], addrmask[i]); 141 panic("malloc: data modified on freelist"); 142 } 143 #endif /* DIAGNOSTIC */ 144 #ifdef KMEMSTATS 145 kup = btokup(va); 146 if (kup->ku_indx != indx) 147 panic("malloc: wrong bucket"); 148 if (kup->ku_freecnt == 0) 149 panic("malloc: lost data"); 150 kup->ku_freecnt--; 151 kbp->kb_totalfree--; 152 ksp->ks_memuse += 1 << indx; 153 out: 154 kbp->kb_calls++; 155 ksp->ks_inuse++; 156 ksp->ks_calls++; 157 if (ksp->ks_memuse > ksp->ks_maxused) 158 ksp->ks_maxused = ksp->ks_memuse; 159 #else 160 out: 161 #endif 162 splx(s); 163 return ((void *) va); 164 } 165 166 /* 167 * Free a block of memory allocated by malloc. 168 */ 169 void 170 free(addr, type) 171 void *addr; 172 int type; 173 { 174 register struct kmembuckets *kbp; 175 register struct kmemusage *kup; 176 long size; 177 int s; 178 #ifdef DIAGNOSTIC 179 caddr_t cp; 180 long alloc, copysize; 181 #endif 182 #ifdef KMEMSTATS 183 register struct kmemstats *ksp = &kmemstats[type]; 184 #endif 185 186 kup = btokup(addr); 187 size = 1 << kup->ku_indx; 188 kbp = &bucket[kup->ku_indx]; 189 s = splimp(); 190 #ifdef DIAGNOSTIC 191 /* 192 * Check for returns of data that do not point to the 193 * beginning of the allocation. 194 */ 195 if (size > NBPG * CLSIZE) 196 alloc = addrmask[BUCKETINDX(NBPG * CLSIZE)]; 197 else 198 alloc = addrmask[kup->ku_indx]; 199 if (((u_long)addr & alloc) != 0) { 200 printf("free: unaligned addr 0x%x, size %d, type %d, mask %d\n", 201 addr, size, type, alloc); 202 panic("free: unaligned addr"); 203 } 204 #endif /* DIAGNOSTIC */ 205 if (size > MAXALLOCSAVE) { 206 kmem_free(kmem_map, (vm_offset_t)addr, ctob(kup->ku_pagecnt)); 207 #ifdef KMEMSTATS 208 size = kup->ku_pagecnt << PGSHIFT; 209 ksp->ks_memuse -= size; 210 kup->ku_indx = 0; 211 kup->ku_pagecnt = 0; 212 if (ksp->ks_memuse + size >= ksp->ks_limit && 213 ksp->ks_memuse < ksp->ks_limit) 214 wakeup((caddr_t)ksp); 215 ksp->ks_inuse--; 216 kbp->kb_total -= 1; 217 #endif 218 splx(s); 219 return; 220 } 221 #ifdef DIAGNOSTIC 222 /* 223 * Check for multiple frees. Use a quick check to see if 224 * it looks free before laboriously searching the freelist. 225 */ 226 *(caddr_t *)addr = (char *)WEIRD_ADDR; 227 copysize = size < sizeof addrmask ? size : sizeof addrmask; 228 if (!bcmp(addrmask, addr, copysize)) { 229 for (cp = kbp->kb_next; cp; cp = *(caddr_t *)cp) { 230 if (addr == cp) { 231 printf("multiply freed item 0x%x\n", addr); 232 panic("free: duplicated free"); 233 } 234 } 235 } 236 /* 237 * Copy in known text to detect modification after freeing 238 * and to make it look free. 239 */ 240 bcopy(addrmask, addr, copysize); 241 #endif /* DIAGNOSTIC */ 242 #ifdef KMEMSTATS 243 kup->ku_freecnt++; 244 if (kup->ku_freecnt >= kbp->kb_elmpercl) 245 if (kup->ku_freecnt > kbp->kb_elmpercl) 246 panic("free: multiple frees"); 247 else if (kbp->kb_totalfree > kbp->kb_highwat) 248 kbp->kb_couldfree++; 249 kbp->kb_totalfree++; 250 ksp->ks_memuse -= size; 251 if (ksp->ks_memuse + size >= ksp->ks_limit && 252 ksp->ks_memuse < ksp->ks_limit) 253 wakeup((caddr_t)ksp); 254 ksp->ks_inuse--; 255 #endif 256 *(caddr_t *)addr = kbp->kb_next; 257 kbp->kb_next = addr; 258 splx(s); 259 } 260 261 /* 262 * Initialize the kernel memory allocator 263 */ 264 kmeminit() 265 { 266 register long indx; 267 int npg; 268 269 #if ((MAXALLOCSAVE & (MAXALLOCSAVE - 1)) != 0) 270 ERROR!_kmeminit:_MAXALLOCSAVE_not_power_of_2 271 #endif 272 #if (MAXALLOCSAVE > MINALLOCSIZE * 32768) 273 ERROR!_kmeminit:_MAXALLOCSAVE_too_big 274 #endif 275 #if (MAXALLOCSAVE < CLBYTES) 276 ERROR!_kmeminit:_MAXALLOCSAVE_too_small 277 #endif 278 npg = VM_KMEM_SIZE/ NBPG; 279 kmemusage = (struct kmemusage *) kmem_alloc(kernel_map, 280 (vm_size_t)(npg * sizeof(struct kmemusage))); 281 kmem_map = kmem_suballoc(kernel_map, (vm_offset_t)&kmembase, 282 (vm_offset_t)&kmemlimit, (vm_size_t)(npg * NBPG), FALSE); 283 #ifdef KMEMSTATS 284 for (indx = 0; indx < MINBUCKET + 16; indx++) { 285 if (1 << indx >= CLBYTES) 286 bucket[indx].kb_elmpercl = 1; 287 else 288 bucket[indx].kb_elmpercl = CLBYTES / (1 << indx); 289 bucket[indx].kb_highwat = 5 * bucket[indx].kb_elmpercl; 290 } 291 for (indx = 0; indx < M_LAST; indx++) 292 kmemstats[indx].ks_limit = npg * NBPG * 6 / 10; 293 #endif 294 } 295