diff options
Diffstat (limited to 'src/lib/libc/stdlib/malloc.c')
| -rw-r--r-- | src/lib/libc/stdlib/malloc.c | 1515 |
1 files changed, 1515 insertions, 0 deletions
diff --git a/src/lib/libc/stdlib/malloc.c b/src/lib/libc/stdlib/malloc.c new file mode 100644 index 0000000000..902b69c216 --- /dev/null +++ b/src/lib/libc/stdlib/malloc.c | |||
| @@ -0,0 +1,1515 @@ | |||
| 1 | /* $OpenBSD: malloc.c,v 1.125 2010/05/18 22:24:55 tedu Exp $ */ | ||
| 2 | /* | ||
| 3 | * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net> | ||
| 4 | * | ||
| 5 | * Permission to use, copy, modify, and distribute this software for any | ||
| 6 | * purpose with or without fee is hereby granted, provided that the above | ||
| 7 | * copyright notice and this permission notice appear in all copies. | ||
| 8 | * | ||
| 9 | * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES | ||
| 10 | * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF | ||
| 11 | * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR | ||
| 12 | * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES | ||
| 13 | * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN | ||
| 14 | * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF | ||
| 15 | * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. | ||
| 16 | */ | ||
| 17 | |||
| 18 | /* | ||
| 19 | * Parts of this code, mainly the sub page sized chunk management code is | ||
| 20 | * derived from the malloc implementation with the following license: | ||
| 21 | */ | ||
| 22 | /* | ||
| 23 | * ---------------------------------------------------------------------------- | ||
| 24 | * "THE BEER-WARE LICENSE" (Revision 42): | ||
| 25 | * <phk@FreeBSD.ORG> wrote this file. As long as you retain this notice you | ||
| 26 | * can do whatever you want with this stuff. If we meet some day, and you think | ||
| 27 | * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp | ||
| 28 | * ---------------------------------------------------------------------------- | ||
| 29 | */ | ||
| 30 | |||
| 31 | /* #define MALLOC_STATS */ | ||
| 32 | |||
| 33 | #include <sys/types.h> | ||
| 34 | #include <sys/param.h> | ||
| 35 | #include <sys/queue.h> | ||
| 36 | #include <sys/mman.h> | ||
| 37 | #include <sys/uio.h> | ||
| 38 | #include <errno.h> | ||
| 39 | #include <stdint.h> | ||
| 40 | #include <stdlib.h> | ||
| 41 | #include <string.h> | ||
| 42 | #include <stdio.h> | ||
| 43 | #include <unistd.h> | ||
| 44 | |||
| 45 | #ifdef MALLOC_STATS | ||
| 46 | #include <fcntl.h> | ||
| 47 | #endif | ||
| 48 | |||
| 49 | #include "thread_private.h" | ||
| 50 | |||
| 51 | #define MALLOC_MINSHIFT 4 | ||
| 52 | #define MALLOC_MAXSHIFT 16 | ||
| 53 | |||
| 54 | #if defined(__sparc__) && !defined(__sparcv9__) | ||
| 55 | #define MALLOC_PAGESHIFT (13U) | ||
| 56 | #elif defined(__mips64__) | ||
| 57 | #define MALLOC_PAGESHIFT (14U) | ||
| 58 | #else | ||
| 59 | #define MALLOC_PAGESHIFT (PGSHIFT) | ||
| 60 | #endif | ||
| 61 | |||
| 62 | #define MALLOC_PAGESIZE (1UL << MALLOC_PAGESHIFT) | ||
| 63 | #define MALLOC_MINSIZE (1UL << MALLOC_MINSHIFT) | ||
| 64 | #define MALLOC_PAGEMASK (MALLOC_PAGESIZE - 1) | ||
| 65 | #define MASK_POINTER(p) ((void *)(((uintptr_t)(p)) & ~MALLOC_PAGEMASK)) | ||
| 66 | |||
| 67 | #define MALLOC_MAXCHUNK (1 << (MALLOC_PAGESHIFT-1)) | ||
| 68 | #define MALLOC_MAXCACHE 256 | ||
| 69 | #define MALLOC_DELAYED_CHUNKS 15 /* max of getrnibble() */ | ||
| 70 | /* | ||
| 71 | * When the P option is active, we move allocations between half a page | ||
| 72 | * and a whole page towards the end, subject to alignment constraints. | ||
| 73 | * This is the extra headroom we allow. Set to zero to be the most | ||
| 74 | * strict. | ||
| 75 | */ | ||
| 76 | #define MALLOC_LEEWAY 0 | ||
| 77 | |||
| 78 | #define PAGEROUND(x) (((x) + (MALLOC_PAGEMASK)) & ~MALLOC_PAGEMASK) | ||
| 79 | |||
| 80 | /* | ||
| 81 | * What to use for Junk. This is the byte value we use to fill with | ||
| 82 | * when the 'J' option is enabled. Use SOME_JUNK right after alloc, | ||
| 83 | * and SOME_FREEJUNK right before free. | ||
| 84 | */ | ||
| 85 | #define SOME_JUNK 0xd0 /* as in "Duh" :-) */ | ||
| 86 | #define SOME_FREEJUNK 0xdf | ||
| 87 | |||
| 88 | #define MMAP(sz) mmap(NULL, (size_t)(sz), PROT_READ | PROT_WRITE, \ | ||
| 89 | MAP_ANON | MAP_PRIVATE, -1, (off_t) 0) | ||
| 90 | |||
| 91 | #define MMAPA(a,sz) mmap((a), (size_t)(sz), PROT_READ | PROT_WRITE, \ | ||
| 92 | MAP_ANON | MAP_PRIVATE, -1, (off_t) 0) | ||
| 93 | |||
| 94 | struct region_info { | ||
| 95 | void *p; /* page; low bits used to mark chunks */ | ||
| 96 | uintptr_t size; /* size for pages, or chunk_info pointer */ | ||
| 97 | }; | ||
| 98 | |||
| 99 | LIST_HEAD(chunk_head, chunk_info); | ||
| 100 | |||
| 101 | struct dir_info { | ||
| 102 | u_int32_t canary1; | ||
| 103 | struct region_info *r; /* region slots */ | ||
| 104 | size_t regions_total; /* number of region slots */ | ||
| 105 | size_t regions_bits; /* log2 of total */ | ||
| 106 | size_t regions_free; /* number of free slots */ | ||
| 107 | /* list of free chunk info structs */ | ||
| 108 | struct chunk_head chunk_info_list; | ||
| 109 | /* lists of chunks with free slots */ | ||
| 110 | struct chunk_head chunk_dir[MALLOC_MAXSHIFT]; | ||
| 111 | size_t free_regions_size; /* free pages cached */ | ||
| 112 | /* free pages cache */ | ||
| 113 | struct region_info free_regions[MALLOC_MAXCACHE]; | ||
| 114 | /* delayed free chunk slots */ | ||
| 115 | void *delayed_chunks[MALLOC_DELAYED_CHUNKS + 1]; | ||
| 116 | #ifdef MALLOC_STATS | ||
| 117 | size_t inserts; | ||
| 118 | size_t insert_collisions; | ||
| 119 | size_t finds; | ||
| 120 | size_t find_collisions; | ||
| 121 | size_t deletes; | ||
| 122 | size_t delete_moves; | ||
| 123 | size_t cheap_realloc_tries; | ||
| 124 | size_t cheap_reallocs; | ||
| 125 | #define STATS_INC(x) ((x)++) | ||
| 126 | #define STATS_ZERO(x) ((x) = 0) | ||
| 127 | #else | ||
| 128 | #define STATS_INC(x) /* nothing */ | ||
| 129 | #define STATS_ZERO(x) /* nothing */ | ||
| 130 | #endif /* MALLOC_STATS */ | ||
| 131 | u_int32_t canary2; | ||
| 132 | }; | ||
| 133 | #define DIR_INFO_RSZ ((sizeof(struct dir_info) + MALLOC_PAGEMASK) & \ | ||
| 134 | ~MALLOC_PAGEMASK) | ||
| 135 | |||
| 136 | /* | ||
| 137 | * This structure describes a page worth of chunks. | ||
| 138 | * | ||
| 139 | * How many bits per u_long in the bitmap | ||
| 140 | */ | ||
| 141 | #define MALLOC_BITS (NBBY * sizeof(u_long)) | ||
| 142 | struct chunk_info { | ||
| 143 | LIST_ENTRY(chunk_info) entries; | ||
| 144 | void *page; /* pointer to the page */ | ||
| 145 | u_int32_t canary; | ||
| 146 | u_short size; /* size of this page's chunks */ | ||
| 147 | u_short shift; /* how far to shift for this size */ | ||
| 148 | u_short free; /* how many free chunks */ | ||
| 149 | u_short total; /* how many chunk */ | ||
| 150 | /* which chunks are free */ | ||
| 151 | u_long bits[(MALLOC_PAGESIZE / MALLOC_MINSIZE) / MALLOC_BITS]; | ||
| 152 | }; | ||
| 153 | |||
| 154 | struct malloc_readonly { | ||
| 155 | struct dir_info *g_pool; /* Main bookkeeping information */ | ||
| 156 | int malloc_abort; /* abort() on error */ | ||
| 157 | int malloc_freeprot; /* mprotect free pages PROT_NONE? */ | ||
| 158 | int malloc_hint; /* call madvice on free pages? */ | ||
| 159 | int malloc_junk; /* junk fill? */ | ||
| 160 | int malloc_move; /* move allocations to end of page? */ | ||
| 161 | int malloc_realloc; /* always realloc? */ | ||
| 162 | int malloc_xmalloc; /* xmalloc behaviour? */ | ||
| 163 | int malloc_zero; /* zero fill? */ | ||
| 164 | size_t malloc_guard; /* use guard pages after allocations? */ | ||
| 165 | u_int malloc_cache; /* free pages we cache */ | ||
| 166 | #ifdef MALLOC_STATS | ||
| 167 | int malloc_stats; /* dump statistics at end */ | ||
| 168 | #endif | ||
| 169 | u_int32_t malloc_canary; /* Matched against ones in g_pool */ | ||
| 170 | }; | ||
| 171 | |||
| 172 | /* This object is mapped PROT_READ after initialisation to prevent tampering */ | ||
| 173 | static union { | ||
| 174 | struct malloc_readonly mopts; | ||
| 175 | u_char _pad[MALLOC_PAGESIZE]; | ||
| 176 | } malloc_readonly __attribute__((aligned(MALLOC_PAGESIZE))); | ||
| 177 | #define mopts malloc_readonly.mopts | ||
| 178 | #define g_pool mopts.g_pool | ||
| 179 | |||
| 180 | char *malloc_options; /* compile-time options */ | ||
| 181 | |||
| 182 | static char *malloc_func; /* current function */ | ||
| 183 | static int malloc_active; /* status of malloc */ | ||
| 184 | |||
| 185 | static size_t malloc_guarded; /* bytes used for guards */ | ||
| 186 | static size_t malloc_used; /* bytes allocated */ | ||
| 187 | |||
| 188 | static size_t rnibblesused; /* random nibbles used */ | ||
| 189 | static u_char rbytes[512]; /* random bytes */ | ||
| 190 | static u_char getrnibble(void); | ||
| 191 | |||
| 192 | extern char *__progname; | ||
| 193 | |||
| 194 | /* low bits of r->p determine size: 0 means >= page size and p->size holding | ||
| 195 | * real size, otherwise r->size is a shift count, or 1 for malloc(0) | ||
| 196 | */ | ||
| 197 | #define REALSIZE(sz, r) \ | ||
| 198 | (sz) = (uintptr_t)(r)->p & MALLOC_PAGEMASK, \ | ||
| 199 | (sz) = ((sz) == 0 ? (r)->size : ((sz) == 1 ? 0 : (1 << ((sz)-1)))) | ||
| 200 | |||
| 201 | static inline size_t | ||
| 202 | hash(void *p) | ||
| 203 | { | ||
| 204 | size_t sum; | ||
| 205 | union { | ||
| 206 | uintptr_t p; | ||
| 207 | unsigned short a[sizeof(void *) / sizeof(short)]; | ||
| 208 | } u; | ||
| 209 | u.p = (uintptr_t)p >> MALLOC_PAGESHIFT; | ||
| 210 | sum = u.a[0]; | ||
| 211 | sum = (sum << 7) - sum + u.a[1]; | ||
| 212 | #ifdef __LP64__ | ||
| 213 | sum = (sum << 7) - sum + u.a[2]; | ||
| 214 | sum = (sum << 7) - sum + u.a[3]; | ||
| 215 | #endif | ||
| 216 | return sum; | ||
| 217 | } | ||
| 218 | |||
| 219 | #ifdef MALLOC_STATS | ||
| 220 | static void | ||
| 221 | dump_chunk(int fd, struct chunk_info *p, int fromfreelist) | ||
| 222 | { | ||
| 223 | char buf[64]; | ||
| 224 | |||
| 225 | while (p != NULL) { | ||
| 226 | snprintf(buf, sizeof(buf), "chunk %d %d/%d %p\n", p->size, | ||
| 227 | p->free, p->total, p->page); | ||
| 228 | write(fd, buf, strlen(buf)); | ||
| 229 | if (!fromfreelist) | ||
| 230 | break; | ||
| 231 | p = LIST_NEXT(p, entries); | ||
| 232 | if (p != NULL) { | ||
| 233 | snprintf(buf, sizeof(buf), " "); | ||
| 234 | write(fd, buf, strlen(buf)); | ||
| 235 | } | ||
| 236 | } | ||
| 237 | } | ||
| 238 | |||
| 239 | static void | ||
| 240 | dump_free_chunk_info(int fd, struct dir_info *d) | ||
| 241 | { | ||
| 242 | char buf[64]; | ||
| 243 | int i; | ||
| 244 | |||
| 245 | snprintf(buf, sizeof(buf), "Free chunk structs:\n"); | ||
| 246 | write(fd, buf, strlen(buf)); | ||
| 247 | for (i = 0; i < MALLOC_MAXSHIFT; i++) { | ||
| 248 | struct chunk_info *p = LIST_FIRST(&d->chunk_dir[i]); | ||
| 249 | if (p != NULL) { | ||
| 250 | snprintf(buf, sizeof(buf), "%2d) ", i); | ||
| 251 | write(fd, buf, strlen(buf)); | ||
| 252 | dump_chunk(fd, p, 1); | ||
| 253 | } | ||
| 254 | } | ||
| 255 | |||
| 256 | } | ||
| 257 | |||
| 258 | static void | ||
| 259 | dump_free_page_info(int fd, struct dir_info *d) | ||
| 260 | { | ||
| 261 | char buf[64]; | ||
| 262 | int i; | ||
| 263 | |||
| 264 | snprintf(buf, sizeof(buf), "Free pages cached: %zu\n", | ||
| 265 | d->free_regions_size); | ||
| 266 | write(fd, buf, strlen(buf)); | ||
| 267 | for (i = 0; i < mopts.malloc_cache; i++) { | ||
| 268 | if (d->free_regions[i].p != NULL) { | ||
| 269 | snprintf(buf, sizeof(buf), "%2d) ", i); | ||
| 270 | write(fd, buf, strlen(buf)); | ||
| 271 | snprintf(buf, sizeof(buf), "free at %p: %zu\n", | ||
| 272 | d->free_regions[i].p, d->free_regions[i].size); | ||
| 273 | write(fd, buf, strlen(buf)); | ||
| 274 | } | ||
| 275 | } | ||
| 276 | } | ||
| 277 | |||
| 278 | static void | ||
| 279 | malloc_dump1(int fd, struct dir_info *d) | ||
| 280 | { | ||
| 281 | char buf[64]; | ||
| 282 | size_t i, realsize; | ||
| 283 | |||
| 284 | snprintf(buf, sizeof(buf), "Malloc dir of %s at %p\n", __progname, d); | ||
| 285 | write(fd, buf, strlen(buf)); | ||
| 286 | if (d == NULL) | ||
| 287 | return; | ||
| 288 | snprintf(buf, sizeof(buf), "Regions slots %zu\n", d->regions_total); | ||
| 289 | write(fd, buf, strlen(buf)); | ||
| 290 | snprintf(buf, sizeof(buf), "Finds %zu/%zu %f\n", d->finds, | ||
| 291 | d->find_collisions, | ||
| 292 | 1.0 + (double)d->find_collisions / d->finds); | ||
| 293 | write(fd, buf, strlen(buf)); | ||
| 294 | snprintf(buf, sizeof(buf), "Inserts %zu/%zu %f\n", d->inserts, | ||
| 295 | d->insert_collisions, | ||
| 296 | 1.0 + (double)d->insert_collisions / d->inserts); | ||
| 297 | write(fd, buf, strlen(buf)); | ||
| 298 | snprintf(buf, sizeof(buf), "Deletes %zu/%zu\n", d->deletes, | ||
| 299 | d->delete_moves); | ||
| 300 | write(fd, buf, strlen(buf)); | ||
| 301 | snprintf(buf, sizeof(buf), "Cheap reallocs %zu/%zu\n", | ||
| 302 | d->cheap_reallocs, d->cheap_realloc_tries); | ||
| 303 | write(fd, buf, strlen(buf)); | ||
| 304 | snprintf(buf, sizeof(buf), "Regions slots free %zu\n", d->regions_free); | ||
| 305 | write(fd, buf, strlen(buf)); | ||
| 306 | for (i = 0; i < d->regions_total; i++) { | ||
| 307 | if (d->r[i].p != NULL) { | ||
| 308 | size_t h = hash(d->r[i].p) & | ||
| 309 | (d->regions_total - 1); | ||
| 310 | snprintf(buf, sizeof(buf), "%4zx) #%zx %zd ", | ||
| 311 | i, h, h - i); | ||
| 312 | write(fd, buf, strlen(buf)); | ||
| 313 | REALSIZE(realsize, &d->r[i]); | ||
| 314 | if (realsize > MALLOC_MAXCHUNK) { | ||
| 315 | snprintf(buf, sizeof(buf), | ||
| 316 | "%p: %zu\n", d->r[i].p, realsize); | ||
| 317 | write(fd, buf, strlen(buf)); | ||
| 318 | } else | ||
| 319 | dump_chunk(fd, | ||
| 320 | (struct chunk_info *)d->r[i].size, 0); | ||
| 321 | } | ||
| 322 | } | ||
| 323 | dump_free_chunk_info(fd, d); | ||
| 324 | dump_free_page_info(fd, d); | ||
| 325 | snprintf(buf, sizeof(buf), "In use %zu\n", malloc_used); | ||
| 326 | write(fd, buf, strlen(buf)); | ||
| 327 | snprintf(buf, sizeof(buf), "Guarded %zu\n", malloc_guarded); | ||
| 328 | write(fd, buf, strlen(buf)); | ||
| 329 | } | ||
| 330 | |||
| 331 | |||
| 332 | void | ||
| 333 | malloc_dump(int fd) | ||
| 334 | { | ||
| 335 | malloc_dump1(fd, g_pool); | ||
| 336 | } | ||
| 337 | |||
| 338 | static void | ||
| 339 | malloc_exit(void) | ||
| 340 | { | ||
| 341 | static const char q[] = "malloc() warning: Couldn't dump stats\n"; | ||
| 342 | int save_errno = errno, fd; | ||
| 343 | |||
| 344 | fd = open("malloc.out", O_RDWR|O_APPEND); | ||
| 345 | if (fd != -1) { | ||
| 346 | malloc_dump(fd); | ||
| 347 | close(fd); | ||
| 348 | } else | ||
| 349 | write(STDERR_FILENO, q, sizeof(q) - 1); | ||
| 350 | errno = save_errno; | ||
| 351 | } | ||
| 352 | #endif /* MALLOC_STATS */ | ||
| 353 | |||
| 354 | |||
| 355 | |||
| 356 | static void | ||
| 357 | wrterror(char *p) | ||
| 358 | { | ||
| 359 | char *q = " error: "; | ||
| 360 | struct iovec iov[5]; | ||
| 361 | |||
| 362 | iov[0].iov_base = __progname; | ||
| 363 | iov[0].iov_len = strlen(__progname); | ||
| 364 | iov[1].iov_base = malloc_func; | ||
| 365 | iov[1].iov_len = strlen(malloc_func); | ||
| 366 | iov[2].iov_base = q; | ||
| 367 | iov[2].iov_len = strlen(q); | ||
| 368 | iov[3].iov_base = p; | ||
| 369 | iov[3].iov_len = strlen(p); | ||
| 370 | iov[4].iov_base = "\n"; | ||
| 371 | iov[4].iov_len = 1; | ||
| 372 | writev(STDERR_FILENO, iov, 5); | ||
| 373 | |||
| 374 | #ifdef MALLOC_STATS | ||
| 375 | if (mopts.malloc_stats) | ||
| 376 | malloc_dump(STDERR_FILENO); | ||
| 377 | #endif /* MALLOC_STATS */ | ||
| 378 | //malloc_active--; | ||
| 379 | if (mopts.malloc_abort) | ||
| 380 | abort(); | ||
| 381 | } | ||
| 382 | |||
| 383 | static void | ||
| 384 | rbytes_init(void) | ||
| 385 | { | ||
| 386 | arc4random_buf(rbytes, sizeof(rbytes)); | ||
| 387 | rnibblesused = 0; | ||
| 388 | } | ||
| 389 | |||
| 390 | static inline u_char | ||
| 391 | getrnibble(void) | ||
| 392 | { | ||
| 393 | u_char x; | ||
| 394 | |||
| 395 | if (rnibblesused >= 2 * sizeof(rbytes)) | ||
| 396 | rbytes_init(); | ||
| 397 | x = rbytes[rnibblesused++ / 2]; | ||
| 398 | return (rnibblesused & 1 ? x & 0xf : x >> 4); | ||
| 399 | } | ||
| 400 | |||
| 401 | /* | ||
| 402 | * Cache maintenance. We keep at most malloc_cache pages cached. | ||
| 403 | * If the cache is becoming full, unmap pages in the cache for real, | ||
| 404 | * and then add the region to the cache | ||
| 405 | * Opposed to the regular region data structure, the sizes in the | ||
| 406 | * cache are in MALLOC_PAGESIZE units. | ||
| 407 | */ | ||
| 408 | static void | ||
| 409 | unmap(struct dir_info *d, void *p, size_t sz) | ||
| 410 | { | ||
| 411 | size_t psz = sz >> MALLOC_PAGESHIFT; | ||
| 412 | size_t rsz, tounmap; | ||
| 413 | struct region_info *r; | ||
| 414 | u_int i, offset; | ||
| 415 | |||
| 416 | if (sz != PAGEROUND(sz)) { | ||
| 417 | wrterror("munmap round"); | ||
| 418 | return; | ||
| 419 | } | ||
| 420 | |||
| 421 | if (psz > mopts.malloc_cache) { | ||
| 422 | if (munmap(p, sz)) | ||
| 423 | wrterror("munmap"); | ||
| 424 | malloc_used -= sz; | ||
| 425 | return; | ||
| 426 | } | ||
| 427 | tounmap = 0; | ||
| 428 | rsz = mopts.malloc_cache - d->free_regions_size; | ||
| 429 | if (psz > rsz) | ||
| 430 | tounmap = psz - rsz; | ||
| 431 | offset = getrnibble(); | ||
| 432 | for (i = 0; tounmap > 0 && i < mopts.malloc_cache; i++) { | ||
| 433 | r = &d->free_regions[(i + offset) & (mopts.malloc_cache - 1)]; | ||
| 434 | if (r->p != NULL) { | ||
| 435 | rsz = r->size << MALLOC_PAGESHIFT; | ||
| 436 | if (munmap(r->p, rsz)) | ||
| 437 | wrterror("munmap"); | ||
| 438 | r->p = NULL; | ||
| 439 | if (tounmap > r->size) | ||
| 440 | tounmap -= r->size; | ||
| 441 | else | ||
| 442 | tounmap = 0; | ||
| 443 | d->free_regions_size -= r->size; | ||
| 444 | r->size = 0; | ||
| 445 | malloc_used -= rsz; | ||
| 446 | } | ||
| 447 | } | ||
| 448 | if (tounmap > 0) | ||
| 449 | wrterror("malloc cache underflow"); | ||
| 450 | for (i = 0; i < mopts.malloc_cache; i++) { | ||
| 451 | r = &d->free_regions[i]; | ||
| 452 | if (r->p == NULL) { | ||
| 453 | if (mopts.malloc_hint) | ||
| 454 | madvise(p, sz, MADV_FREE); | ||
| 455 | if (mopts.malloc_freeprot) | ||
| 456 | mprotect(p, sz, PROT_NONE); | ||
| 457 | r->p = p; | ||
| 458 | r->size = psz; | ||
| 459 | d->free_regions_size += psz; | ||
| 460 | break; | ||
| 461 | } | ||
| 462 | } | ||
| 463 | if (i == mopts.malloc_cache) | ||
| 464 | wrterror("malloc free slot lost"); | ||
| 465 | if (d->free_regions_size > mopts.malloc_cache) | ||
| 466 | wrterror("malloc cache overflow"); | ||
| 467 | } | ||
| 468 | |||
| 469 | static void | ||
| 470 | zapcacheregion(struct dir_info *d, void *p) | ||
| 471 | { | ||
| 472 | u_int i; | ||
| 473 | struct region_info *r; | ||
| 474 | size_t rsz; | ||
| 475 | |||
| 476 | for (i = 0; i < mopts.malloc_cache; i++) { | ||
| 477 | r = &d->free_regions[i]; | ||
| 478 | if (r->p == p) { | ||
| 479 | rsz = r->size << MALLOC_PAGESHIFT; | ||
| 480 | if (munmap(r->p, rsz)) | ||
| 481 | wrterror("munmap"); | ||
| 482 | r->p = NULL; | ||
| 483 | d->free_regions_size -= r->size; | ||
| 484 | r->size = 0; | ||
| 485 | malloc_used -= rsz; | ||
| 486 | } | ||
| 487 | } | ||
| 488 | } | ||
| 489 | |||
| 490 | static void * | ||
| 491 | map(struct dir_info *d, size_t sz, int zero_fill) | ||
| 492 | { | ||
| 493 | size_t psz = sz >> MALLOC_PAGESHIFT; | ||
| 494 | struct region_info *r, *big = NULL; | ||
| 495 | u_int i, offset; | ||
| 496 | void *p; | ||
| 497 | |||
| 498 | if (mopts.malloc_canary != (d->canary1 ^ (u_int32_t)(uintptr_t)d) || | ||
| 499 | d->canary1 != ~d->canary2) | ||
| 500 | wrterror("internal struct corrupt"); | ||
| 501 | if (sz != PAGEROUND(sz)) { | ||
| 502 | wrterror("map round"); | ||
| 503 | return NULL; | ||
| 504 | } | ||
| 505 | if (psz > d->free_regions_size) { | ||
| 506 | p = MMAP(sz); | ||
| 507 | if (p != MAP_FAILED) | ||
| 508 | malloc_used += sz; | ||
| 509 | /* zero fill not needed */ | ||
| 510 | return p; | ||
| 511 | } | ||
| 512 | offset = getrnibble(); | ||
| 513 | for (i = 0; i < mopts.malloc_cache; i++) { | ||
| 514 | r = &d->free_regions[(i + offset) & (mopts.malloc_cache - 1)]; | ||
| 515 | if (r->p != NULL) { | ||
| 516 | if (r->size == psz) { | ||
| 517 | p = r->p; | ||
| 518 | if (mopts.malloc_freeprot) | ||
| 519 | mprotect(p, sz, PROT_READ | PROT_WRITE); | ||
| 520 | if (mopts.malloc_hint) | ||
| 521 | madvise(p, sz, MADV_NORMAL); | ||
| 522 | r->p = NULL; | ||
| 523 | r->size = 0; | ||
| 524 | d->free_regions_size -= psz; | ||
| 525 | if (zero_fill) | ||
| 526 | memset(p, 0, sz); | ||
| 527 | else if (mopts.malloc_junk && | ||
| 528 | mopts.malloc_freeprot) | ||
| 529 | memset(p, SOME_FREEJUNK, sz); | ||
| 530 | return p; | ||
| 531 | } else if (r->size > psz) | ||
| 532 | big = r; | ||
| 533 | } | ||
| 534 | } | ||
| 535 | if (big != NULL) { | ||
| 536 | r = big; | ||
| 537 | p = (char *)r->p + ((r->size - psz) << MALLOC_PAGESHIFT); | ||
| 538 | if (mopts.malloc_freeprot) | ||
| 539 | mprotect(p, sz, PROT_READ | PROT_WRITE); | ||
| 540 | if (mopts.malloc_hint) | ||
| 541 | madvise(p, sz, MADV_NORMAL); | ||
| 542 | r->size -= psz; | ||
| 543 | d->free_regions_size -= psz; | ||
| 544 | if (zero_fill) | ||
| 545 | memset(p, 0, sz); | ||
| 546 | else if (mopts.malloc_junk && mopts.malloc_freeprot) | ||
| 547 | memset(p, SOME_FREEJUNK, sz); | ||
| 548 | return p; | ||
| 549 | } | ||
| 550 | p = MMAP(sz); | ||
| 551 | if (p != MAP_FAILED) | ||
| 552 | malloc_used += sz; | ||
| 553 | if (d->free_regions_size > mopts.malloc_cache) | ||
| 554 | wrterror("malloc cache"); | ||
| 555 | /* zero fill not needed */ | ||
| 556 | return p; | ||
| 557 | } | ||
| 558 | |||
| 559 | /* | ||
| 560 | * Initialize a dir_info, which should have been cleared by caller | ||
| 561 | */ | ||
| 562 | static int | ||
| 563 | omalloc_init(struct dir_info **dp) | ||
| 564 | { | ||
| 565 | char *p, b[64]; | ||
| 566 | int i, j; | ||
| 567 | size_t d_avail, regioninfo_size; | ||
| 568 | struct dir_info *d; | ||
| 569 | |||
| 570 | rbytes_init(); | ||
| 571 | |||
| 572 | /* | ||
| 573 | * Default options | ||
| 574 | */ | ||
| 575 | mopts.malloc_abort = 1; | ||
| 576 | mopts.malloc_move = 1; | ||
| 577 | mopts.malloc_cache = 64; | ||
| 578 | |||
| 579 | for (i = 0; i < 3; i++) { | ||
| 580 | switch (i) { | ||
| 581 | case 0: | ||
| 582 | j = readlink("/etc/malloc.conf", b, sizeof b - 1); | ||
| 583 | if (j <= 0) | ||
| 584 | continue; | ||
| 585 | b[j] = '\0'; | ||
| 586 | p = b; | ||
| 587 | break; | ||
| 588 | case 1: | ||
| 589 | if (issetugid() == 0) | ||
| 590 | p = getenv("MALLOC_OPTIONS"); | ||
| 591 | else | ||
| 592 | continue; | ||
| 593 | break; | ||
| 594 | case 2: | ||
| 595 | p = malloc_options; | ||
| 596 | break; | ||
| 597 | default: | ||
| 598 | p = NULL; | ||
| 599 | } | ||
| 600 | |||
| 601 | for (; p != NULL && *p != '\0'; p++) { | ||
| 602 | switch (*p) { | ||
| 603 | case '>': | ||
| 604 | mopts.malloc_cache <<= 1; | ||
| 605 | if (mopts.malloc_cache > MALLOC_MAXCACHE) | ||
| 606 | mopts.malloc_cache = MALLOC_MAXCACHE; | ||
| 607 | break; | ||
| 608 | case '<': | ||
| 609 | mopts.malloc_cache >>= 1; | ||
| 610 | break; | ||
| 611 | case 'a': | ||
| 612 | mopts.malloc_abort = 0; | ||
| 613 | break; | ||
| 614 | case 'A': | ||
| 615 | mopts.malloc_abort = 1; | ||
| 616 | break; | ||
| 617 | #ifdef MALLOC_STATS | ||
| 618 | case 'd': | ||
| 619 | mopts.malloc_stats = 0; | ||
| 620 | break; | ||
| 621 | case 'D': | ||
| 622 | mopts.malloc_stats = 1; | ||
| 623 | break; | ||
| 624 | #endif /* MALLOC_STATS */ | ||
| 625 | case 'f': | ||
| 626 | mopts.malloc_freeprot = 0; | ||
| 627 | break; | ||
| 628 | case 'F': | ||
| 629 | mopts.malloc_freeprot = 1; | ||
| 630 | break; | ||
| 631 | case 'g': | ||
| 632 | mopts.malloc_guard = 0; | ||
| 633 | break; | ||
| 634 | case 'G': | ||
| 635 | mopts.malloc_guard = MALLOC_PAGESIZE; | ||
| 636 | break; | ||
| 637 | case 'h': | ||
| 638 | mopts.malloc_hint = 0; | ||
| 639 | break; | ||
| 640 | case 'H': | ||
| 641 | mopts.malloc_hint = 1; | ||
| 642 | break; | ||
| 643 | case 'j': | ||
| 644 | mopts.malloc_junk = 0; | ||
| 645 | break; | ||
| 646 | case 'J': | ||
| 647 | mopts.malloc_junk = 1; | ||
| 648 | break; | ||
| 649 | case 'n': | ||
| 650 | case 'N': | ||
| 651 | break; | ||
| 652 | case 'p': | ||
| 653 | mopts.malloc_move = 0; | ||
| 654 | break; | ||
| 655 | case 'P': | ||
| 656 | mopts.malloc_move = 1; | ||
| 657 | break; | ||
| 658 | case 'r': | ||
| 659 | mopts.malloc_realloc = 0; | ||
| 660 | break; | ||
| 661 | case 'R': | ||
| 662 | mopts.malloc_realloc = 1; | ||
| 663 | break; | ||
| 664 | case 'S': | ||
| 665 | mopts.malloc_freeprot = mopts.malloc_junk = 1; | ||
| 666 | mopts.malloc_guard = MALLOC_PAGESIZE; | ||
| 667 | break; | ||
| 668 | case 'x': | ||
| 669 | mopts.malloc_xmalloc = 0; | ||
| 670 | break; | ||
| 671 | case 'X': | ||
| 672 | mopts.malloc_xmalloc = 1; | ||
| 673 | break; | ||
| 674 | case 'z': | ||
| 675 | mopts.malloc_zero = 0; | ||
| 676 | break; | ||
| 677 | case 'Z': | ||
| 678 | mopts.malloc_zero = 1; | ||
| 679 | break; | ||
| 680 | default: { | ||
| 681 | static const char q[] = "malloc() warning: " | ||
| 682 | "unknown char in MALLOC_OPTIONS\n"; | ||
| 683 | write(STDERR_FILENO, q, sizeof(q) - 1); | ||
| 684 | break; | ||
| 685 | } | ||
| 686 | } | ||
| 687 | } | ||
| 688 | } | ||
| 689 | |||
| 690 | /* | ||
| 691 | * We want junk in the entire allocation, and zero only in the part | ||
| 692 | * the user asked for. | ||
| 693 | */ | ||
| 694 | if (mopts.malloc_zero) | ||
| 695 | mopts.malloc_junk = 1; | ||
| 696 | |||
| 697 | #ifdef MALLOC_STATS | ||
| 698 | if (mopts.malloc_stats && (atexit(malloc_exit) == -1)) { | ||
| 699 | static const char q[] = "malloc() warning: atexit(2) failed." | ||
| 700 | " Will not be able to dump stats on exit\n"; | ||
| 701 | write(STDERR_FILENO, q, sizeof(q) - 1); | ||
| 702 | } | ||
| 703 | #endif /* MALLOC_STATS */ | ||
| 704 | |||
| 705 | while ((mopts.malloc_canary = arc4random()) == 0) | ||
| 706 | ; | ||
| 707 | |||
| 708 | /* | ||
| 709 | * Allocate dir_info with a guard page on either side. Also | ||
| 710 | * randomise offset inside the page at which the dir_info | ||
| 711 | * lies (subject to alignment by 1 << MALLOC_MINSHIFT) | ||
| 712 | */ | ||
| 713 | if ((p = MMAP(DIR_INFO_RSZ + (MALLOC_PAGESIZE * 2))) == MAP_FAILED) | ||
| 714 | return -1; | ||
| 715 | mprotect(p, MALLOC_PAGESIZE, PROT_NONE); | ||
| 716 | mprotect(p + MALLOC_PAGESIZE + DIR_INFO_RSZ, | ||
| 717 | MALLOC_PAGESIZE, PROT_NONE); | ||
| 718 | d_avail = (DIR_INFO_RSZ - sizeof(*d)) >> MALLOC_MINSHIFT; | ||
| 719 | d = (struct dir_info *)(p + MALLOC_PAGESIZE + | ||
| 720 | (arc4random_uniform(d_avail) << MALLOC_MINSHIFT)); | ||
| 721 | |||
| 722 | d->regions_bits = 9; | ||
| 723 | d->regions_free = d->regions_total = 1 << d->regions_bits; | ||
| 724 | regioninfo_size = d->regions_total * sizeof(struct region_info); | ||
| 725 | d->r = MMAP(regioninfo_size); | ||
| 726 | if (d->r == MAP_FAILED) { | ||
| 727 | wrterror("malloc init mmap failed"); | ||
| 728 | d->regions_total = 0; | ||
| 729 | return 1; | ||
| 730 | } | ||
| 731 | LIST_INIT(&d->chunk_info_list); | ||
| 732 | for (i = 0; i < MALLOC_MAXSHIFT; i++) | ||
| 733 | LIST_INIT(&d->chunk_dir[i]); | ||
| 734 | malloc_used += regioninfo_size; | ||
| 735 | d->canary1 = mopts.malloc_canary ^ (u_int32_t)(uintptr_t)d; | ||
| 736 | d->canary2 = ~d->canary1; | ||
| 737 | |||
| 738 | *dp = d; | ||
| 739 | |||
| 740 | /* | ||
| 741 | * Options have been set and will never be reset. | ||
| 742 | * Prevent further tampering with them. | ||
| 743 | */ | ||
| 744 | if (((uintptr_t)&malloc_readonly & MALLOC_PAGEMASK) == 0) | ||
| 745 | mprotect(&malloc_readonly, sizeof(malloc_readonly), PROT_READ); | ||
| 746 | |||
| 747 | return 0; | ||
| 748 | } | ||
| 749 | |||
| 750 | static int | ||
| 751 | omalloc_grow(struct dir_info *d) | ||
| 752 | { | ||
| 753 | size_t newbits; | ||
| 754 | size_t newtotal; | ||
| 755 | size_t newsize; | ||
| 756 | size_t mask; | ||
| 757 | size_t i; | ||
| 758 | struct region_info *p; | ||
| 759 | |||
| 760 | if (d->regions_total > SIZE_MAX / sizeof(struct region_info) / 2 ) | ||
| 761 | return 1; | ||
| 762 | |||
| 763 | newbits = d->regions_bits + 1; | ||
| 764 | newtotal = d->regions_total * 2; | ||
| 765 | newsize = newtotal * sizeof(struct region_info); | ||
| 766 | mask = newtotal - 1; | ||
| 767 | |||
| 768 | p = MMAP(newsize); | ||
| 769 | if (p == MAP_FAILED) | ||
| 770 | return 1; | ||
| 771 | |||
| 772 | malloc_used += newsize; | ||
| 773 | memset(p, 0, newsize); | ||
| 774 | STATS_ZERO(d->inserts); | ||
| 775 | STATS_ZERO(d->insert_collisions); | ||
| 776 | for (i = 0; i < d->regions_total; i++) { | ||
| 777 | void *q = d->r[i].p; | ||
| 778 | if (q != NULL) { | ||
| 779 | size_t index = hash(q) & mask; | ||
| 780 | STATS_INC(d->inserts); | ||
| 781 | while (p[index].p != NULL) { | ||
| 782 | index = (index - 1) & mask; | ||
| 783 | STATS_INC(d->insert_collisions); | ||
| 784 | } | ||
| 785 | p[index] = d->r[i]; | ||
| 786 | } | ||
| 787 | } | ||
| 788 | /* avoid pages containing meta info to end up in cache */ | ||
| 789 | if (munmap(d->r, d->regions_total * sizeof(struct region_info))) | ||
| 790 | wrterror("munmap"); | ||
| 791 | else | ||
| 792 | malloc_used -= d->regions_total * sizeof(struct region_info); | ||
| 793 | d->regions_free = d->regions_free + d->regions_total; | ||
| 794 | d->regions_total = newtotal; | ||
| 795 | d->regions_bits = newbits; | ||
| 796 | d->r = p; | ||
| 797 | return 0; | ||
| 798 | } | ||
| 799 | |||
| 800 | static struct chunk_info * | ||
| 801 | alloc_chunk_info(struct dir_info *d) | ||
| 802 | { | ||
| 803 | struct chunk_info *p; | ||
| 804 | int i; | ||
| 805 | |||
| 806 | if (LIST_EMPTY(&d->chunk_info_list)) { | ||
| 807 | p = MMAP(MALLOC_PAGESIZE); | ||
| 808 | if (p == MAP_FAILED) | ||
| 809 | return NULL; | ||
| 810 | malloc_used += MALLOC_PAGESIZE; | ||
| 811 | for (i = 0; i < MALLOC_PAGESIZE / sizeof(*p); i++) | ||
| 812 | LIST_INSERT_HEAD(&d->chunk_info_list, &p[i], entries); | ||
| 813 | } | ||
| 814 | p = LIST_FIRST(&d->chunk_info_list); | ||
| 815 | LIST_REMOVE(p, entries); | ||
| 816 | memset(p, 0, sizeof *p); | ||
| 817 | p->canary = d->canary1; | ||
| 818 | return p; | ||
| 819 | } | ||
| 820 | |||
| 821 | static int | ||
| 822 | insert(struct dir_info *d, void *p, size_t sz) | ||
| 823 | { | ||
| 824 | size_t index; | ||
| 825 | size_t mask; | ||
| 826 | void *q; | ||
| 827 | |||
| 828 | if (d->regions_free * 4 < d->regions_total) { | ||
| 829 | if (omalloc_grow(d)) | ||
| 830 | return 1; | ||
| 831 | } | ||
| 832 | mask = d->regions_total - 1; | ||
| 833 | index = hash(p) & mask; | ||
| 834 | q = d->r[index].p; | ||
| 835 | STATS_INC(d->inserts); | ||
| 836 | while (q != NULL) { | ||
| 837 | index = (index - 1) & mask; | ||
| 838 | q = d->r[index].p; | ||
| 839 | STATS_INC(d->insert_collisions); | ||
| 840 | } | ||
| 841 | d->r[index].p = p; | ||
| 842 | d->r[index].size = sz; | ||
| 843 | d->regions_free--; | ||
| 844 | return 0; | ||
| 845 | } | ||
| 846 | |||
| 847 | static struct region_info * | ||
| 848 | find(struct dir_info *d, void *p) | ||
| 849 | { | ||
| 850 | size_t index; | ||
| 851 | size_t mask = d->regions_total - 1; | ||
| 852 | void *q, *r; | ||
| 853 | |||
| 854 | if (mopts.malloc_canary != (d->canary1 ^ (u_int32_t)(uintptr_t)d) || | ||
| 855 | d->canary1 != ~d->canary2) | ||
| 856 | wrterror("internal struct corrupt"); | ||
| 857 | p = MASK_POINTER(p); | ||
| 858 | index = hash(p) & mask; | ||
| 859 | r = d->r[index].p; | ||
| 860 | q = MASK_POINTER(r); | ||
| 861 | STATS_INC(d->finds); | ||
| 862 | while (q != p && r != NULL) { | ||
| 863 | index = (index - 1) & mask; | ||
| 864 | r = d->r[index].p; | ||
| 865 | q = MASK_POINTER(r); | ||
| 866 | STATS_INC(d->find_collisions); | ||
| 867 | } | ||
| 868 | return q == p ? &d->r[index] : NULL; | ||
| 869 | } | ||
| 870 | |||
| 871 | static void | ||
| 872 | delete(struct dir_info *d, struct region_info *ri) | ||
| 873 | { | ||
| 874 | /* algorithm R, Knuth Vol III section 6.4 */ | ||
| 875 | size_t mask = d->regions_total - 1; | ||
| 876 | size_t i, j, r; | ||
| 877 | |||
| 878 | if (d->regions_total & (d->regions_total - 1)) | ||
| 879 | wrterror("regions_total not 2^x"); | ||
| 880 | d->regions_free++; | ||
| 881 | STATS_INC(g_pool->deletes); | ||
| 882 | |||
| 883 | i = ri - d->r; | ||
| 884 | for (;;) { | ||
| 885 | d->r[i].p = NULL; | ||
| 886 | d->r[i].size = 0; | ||
| 887 | j = i; | ||
| 888 | for (;;) { | ||
| 889 | i = (i - 1) & mask; | ||
| 890 | if (d->r[i].p == NULL) | ||
| 891 | return; | ||
| 892 | r = hash(d->r[i].p) & mask; | ||
| 893 | if ((i <= r && r < j) || (r < j && j < i) || | ||
| 894 | (j < i && i <= r)) | ||
| 895 | continue; | ||
| 896 | d->r[j] = d->r[i]; | ||
| 897 | STATS_INC(g_pool->delete_moves); | ||
| 898 | break; | ||
| 899 | } | ||
| 900 | |||
| 901 | } | ||
| 902 | } | ||
| 903 | |||
| 904 | /* | ||
| 905 | * Allocate a page of chunks | ||
| 906 | */ | ||
| 907 | static struct chunk_info * | ||
| 908 | omalloc_make_chunks(struct dir_info *d, int bits) | ||
| 909 | { | ||
| 910 | struct chunk_info *bp; | ||
| 911 | void *pp; | ||
| 912 | long i, k; | ||
| 913 | |||
| 914 | /* Allocate a new bucket */ | ||
| 915 | pp = map(d, MALLOC_PAGESIZE, 0); | ||
| 916 | if (pp == MAP_FAILED) | ||
| 917 | return NULL; | ||
| 918 | |||
| 919 | bp = alloc_chunk_info(d); | ||
| 920 | if (bp == NULL) { | ||
| 921 | unmap(d, pp, MALLOC_PAGESIZE); | ||
| 922 | return NULL; | ||
| 923 | } | ||
| 924 | |||
| 925 | /* memory protect the page allocated in the malloc(0) case */ | ||
| 926 | if (bits == 0) { | ||
| 927 | bp->size = 0; | ||
| 928 | bp->shift = 1; | ||
| 929 | i = MALLOC_MINSIZE - 1; | ||
| 930 | while (i >>= 1) | ||
| 931 | bp->shift++; | ||
| 932 | bp->total = bp->free = MALLOC_PAGESIZE >> bp->shift; | ||
| 933 | bp->page = pp; | ||
| 934 | |||
| 935 | k = mprotect(pp, MALLOC_PAGESIZE, PROT_NONE); | ||
| 936 | if (k < 0) { | ||
| 937 | unmap(d, pp, MALLOC_PAGESIZE); | ||
| 938 | LIST_INSERT_HEAD(&d->chunk_info_list, bp, entries); | ||
| 939 | return NULL; | ||
| 940 | } | ||
| 941 | } else { | ||
| 942 | bp->size = (1UL << bits); | ||
| 943 | bp->shift = bits; | ||
| 944 | bp->total = bp->free = MALLOC_PAGESIZE >> bits; | ||
| 945 | bp->page = pp; | ||
| 946 | } | ||
| 947 | |||
| 948 | /* set all valid bits in the bitmap */ | ||
| 949 | k = bp->total; | ||
| 950 | i = 0; | ||
| 951 | |||
| 952 | /* Do a bunch at a time */ | ||
| 953 | for (; (k - i) >= MALLOC_BITS; i += MALLOC_BITS) | ||
| 954 | bp->bits[i / MALLOC_BITS] = ~0UL; | ||
| 955 | |||
| 956 | for (; i < k; i++) | ||
| 957 | bp->bits[i / MALLOC_BITS] |= 1UL << (i % MALLOC_BITS); | ||
| 958 | |||
| 959 | LIST_INSERT_HEAD(&d->chunk_dir[bits], bp, entries); | ||
| 960 | |||
| 961 | bits++; | ||
| 962 | if ((uintptr_t)pp & bits) | ||
| 963 | wrterror("pp & bits"); | ||
| 964 | |||
| 965 | insert(d, (void *)((uintptr_t)pp | bits), (uintptr_t)bp); | ||
| 966 | return bp; | ||
| 967 | } | ||
| 968 | |||
| 969 | |||
| 970 | /* | ||
| 971 | * Allocate a chunk | ||
| 972 | */ | ||
| 973 | static void * | ||
| 974 | malloc_bytes(struct dir_info *d, size_t size) | ||
| 975 | { | ||
| 976 | int i, j; | ||
| 977 | size_t k; | ||
| 978 | u_long u, *lp; | ||
| 979 | struct chunk_info *bp; | ||
| 980 | |||
| 981 | if (mopts.malloc_canary != (d->canary1 ^ (u_int32_t)(uintptr_t)d) || | ||
| 982 | d->canary1 != ~d->canary2) | ||
| 983 | wrterror("internal struct corrupt"); | ||
| 984 | /* Don't bother with anything less than this */ | ||
| 985 | /* unless we have a malloc(0) requests */ | ||
| 986 | if (size != 0 && size < MALLOC_MINSIZE) | ||
| 987 | size = MALLOC_MINSIZE; | ||
| 988 | |||
| 989 | /* Find the right bucket */ | ||
| 990 | if (size == 0) | ||
| 991 | j = 0; | ||
| 992 | else { | ||
| 993 | j = MALLOC_MINSHIFT; | ||
| 994 | i = (size - 1) >> (MALLOC_MINSHIFT - 1); | ||
| 995 | while (i >>= 1) | ||
| 996 | j++; | ||
| 997 | } | ||
| 998 | |||
| 999 | /* If it's empty, make a page more of that size chunks */ | ||
| 1000 | if (LIST_EMPTY(&d->chunk_dir[j])) { | ||
| 1001 | bp = omalloc_make_chunks(d, j); | ||
| 1002 | if (bp == NULL) | ||
| 1003 | return NULL; | ||
| 1004 | } else | ||
| 1005 | bp = LIST_FIRST(&d->chunk_dir[j]); | ||
| 1006 | |||
| 1007 | if (bp->canary != d->canary1) | ||
| 1008 | wrterror("chunk info corrupted"); | ||
| 1009 | /* Find first word of bitmap which isn't empty */ | ||
| 1010 | for (lp = bp->bits; !*lp; lp++) | ||
| 1011 | /* EMPTY */; | ||
| 1012 | |||
| 1013 | /* Find that bit, and tweak it */ | ||
| 1014 | u = 1; | ||
| 1015 | k = 0; | ||
| 1016 | while (!(*lp & u)) { | ||
| 1017 | u += u; | ||
| 1018 | k++; | ||
| 1019 | } | ||
| 1020 | |||
| 1021 | /* advance a random # of positions */ | ||
| 1022 | i = getrnibble() % bp->free; | ||
| 1023 | while (i > 0) { | ||
| 1024 | u += u; | ||
| 1025 | k++; | ||
| 1026 | if (k >= MALLOC_BITS) { | ||
| 1027 | lp++; | ||
| 1028 | u = 1; | ||
| 1029 | k = 0; | ||
| 1030 | } | ||
| 1031 | if (lp - bp->bits > (bp->total - 1) / MALLOC_BITS) { | ||
| 1032 | wrterror("chunk overflow"); | ||
| 1033 | errno = EFAULT; | ||
| 1034 | return (NULL); | ||
| 1035 | } | ||
| 1036 | if (*lp & u) | ||
| 1037 | i--; | ||
| 1038 | } | ||
| 1039 | |||
| 1040 | *lp ^= u; | ||
| 1041 | |||
| 1042 | /* If there are no more free, remove from free-list */ | ||
| 1043 | if (!--bp->free) | ||
| 1044 | LIST_REMOVE(bp, entries); | ||
| 1045 | |||
| 1046 | /* Adjust to the real offset of that chunk */ | ||
| 1047 | k += (lp - bp->bits) * MALLOC_BITS; | ||
| 1048 | k <<= bp->shift; | ||
| 1049 | |||
| 1050 | if (mopts.malloc_junk && bp->size > 0) | ||
| 1051 | memset((char *)bp->page + k, SOME_JUNK, bp->size); | ||
| 1052 | return ((char *)bp->page + k); | ||
| 1053 | } | ||
| 1054 | |||
| 1055 | |||
| 1056 | /* | ||
| 1057 | * Free a chunk, and possibly the page it's on, if the page becomes empty. | ||
| 1058 | */ | ||
| 1059 | static void | ||
| 1060 | free_bytes(struct dir_info *d, struct region_info *r, void *ptr) | ||
| 1061 | { | ||
| 1062 | struct chunk_head *mp; | ||
| 1063 | struct chunk_info *info; | ||
| 1064 | long i; | ||
| 1065 | |||
| 1066 | info = (struct chunk_info *)r->size; | ||
| 1067 | if (info->canary != d->canary1) | ||
| 1068 | wrterror("chunk info corrupted"); | ||
| 1069 | |||
| 1070 | /* Find the chunk number on the page */ | ||
| 1071 | i = ((uintptr_t)ptr & MALLOC_PAGEMASK) >> info->shift; | ||
| 1072 | |||
| 1073 | if ((uintptr_t)ptr & ((1UL << (info->shift)) - 1)) { | ||
| 1074 | wrterror("modified chunk-pointer"); | ||
| 1075 | return; | ||
| 1076 | } | ||
| 1077 | if (info->bits[i / MALLOC_BITS] & (1UL << (i % MALLOC_BITS))) { | ||
| 1078 | wrterror("chunk is already free"); | ||
| 1079 | return; | ||
| 1080 | } | ||
| 1081 | |||
| 1082 | info->bits[i / MALLOC_BITS] |= 1UL << (i % MALLOC_BITS); | ||
| 1083 | info->free++; | ||
| 1084 | |||
| 1085 | if (info->size != 0) | ||
| 1086 | mp = d->chunk_dir + info->shift; | ||
| 1087 | else | ||
| 1088 | mp = d->chunk_dir; | ||
| 1089 | |||
| 1090 | if (info->free == 1) { | ||
| 1091 | /* Page became non-full */ | ||
| 1092 | LIST_INSERT_HEAD(mp, info, entries); | ||
| 1093 | return; | ||
| 1094 | } | ||
| 1095 | if (info->free != info->total) | ||
| 1096 | return; | ||
| 1097 | |||
| 1098 | LIST_REMOVE(info, entries); | ||
| 1099 | |||
| 1100 | if (info->size == 0 && !mopts.malloc_freeprot) | ||
| 1101 | mprotect(info->page, MALLOC_PAGESIZE, PROT_READ | PROT_WRITE); | ||
| 1102 | unmap(d, info->page, MALLOC_PAGESIZE); | ||
| 1103 | |||
| 1104 | delete(d, r); | ||
| 1105 | LIST_INSERT_HEAD(&d->chunk_info_list, info, entries); | ||
| 1106 | } | ||
| 1107 | |||
| 1108 | |||
| 1109 | |||
| 1110 | static void * | ||
| 1111 | omalloc(size_t sz, int zero_fill) | ||
| 1112 | { | ||
| 1113 | void *p; | ||
| 1114 | size_t psz; | ||
| 1115 | |||
| 1116 | if (sz > MALLOC_MAXCHUNK) { | ||
| 1117 | if (sz >= SIZE_MAX - mopts.malloc_guard - MALLOC_PAGESIZE) { | ||
| 1118 | errno = ENOMEM; | ||
| 1119 | return NULL; | ||
| 1120 | } | ||
| 1121 | sz += mopts.malloc_guard; | ||
| 1122 | psz = PAGEROUND(sz); | ||
| 1123 | p = map(g_pool, psz, zero_fill); | ||
| 1124 | if (p == MAP_FAILED) { | ||
| 1125 | errno = ENOMEM; | ||
| 1126 | return NULL; | ||
| 1127 | } | ||
| 1128 | if (insert(g_pool, p, sz)) { | ||
| 1129 | unmap(g_pool, p, psz); | ||
| 1130 | errno = ENOMEM; | ||
| 1131 | return NULL; | ||
| 1132 | } | ||
| 1133 | if (mopts.malloc_guard) { | ||
| 1134 | if (mprotect((char *)p + psz - mopts.malloc_guard, | ||
| 1135 | mopts.malloc_guard, PROT_NONE)) | ||
| 1136 | wrterror("mprotect"); | ||
| 1137 | malloc_guarded += mopts.malloc_guard; | ||
| 1138 | } | ||
| 1139 | |||
| 1140 | if (mopts.malloc_move && | ||
| 1141 | sz - mopts.malloc_guard < MALLOC_PAGESIZE - | ||
| 1142 | MALLOC_LEEWAY) { | ||
| 1143 | /* fill whole allocation */ | ||
| 1144 | if (mopts.malloc_junk) | ||
| 1145 | memset(p, SOME_JUNK, psz - mopts.malloc_guard); | ||
| 1146 | /* shift towards the end */ | ||
| 1147 | p = ((char *)p) + ((MALLOC_PAGESIZE - MALLOC_LEEWAY - | ||
| 1148 | (sz - mopts.malloc_guard)) & ~(MALLOC_MINSIZE-1)); | ||
| 1149 | /* fill zeros if needed and overwritten above */ | ||
| 1150 | if (zero_fill && mopts.malloc_junk) | ||
| 1151 | memset(p, 0, sz - mopts.malloc_guard); | ||
| 1152 | } else { | ||
| 1153 | if (mopts.malloc_junk) { | ||
| 1154 | if (zero_fill) | ||
| 1155 | memset(p + sz - mopts.malloc_guard, | ||
| 1156 | SOME_JUNK, psz - sz); | ||
| 1157 | else | ||
| 1158 | memset(p, SOME_JUNK, | ||
| 1159 | psz - mopts.malloc_guard); | ||
| 1160 | } | ||
| 1161 | } | ||
| 1162 | |||
| 1163 | } else { | ||
| 1164 | /* takes care of SOME_JUNK */ | ||
| 1165 | p = malloc_bytes(g_pool, sz); | ||
| 1166 | if (zero_fill && p != NULL && sz > 0) | ||
| 1167 | memset(p, 0, sz); | ||
| 1168 | } | ||
| 1169 | |||
| 1170 | return p; | ||
| 1171 | } | ||
| 1172 | |||
| 1173 | /* | ||
| 1174 | * Common function for handling recursion. Only | ||
| 1175 | * print the error message once, to avoid making the problem | ||
| 1176 | * potentially worse. | ||
| 1177 | */ | ||
| 1178 | static void | ||
| 1179 | malloc_recurse(void) | ||
| 1180 | { | ||
| 1181 | static int noprint; | ||
| 1182 | |||
| 1183 | if (noprint == 0) { | ||
| 1184 | noprint = 1; | ||
| 1185 | wrterror("recursive call"); | ||
| 1186 | } | ||
| 1187 | malloc_active--; | ||
| 1188 | _MALLOC_UNLOCK(); | ||
| 1189 | errno = EDEADLK; | ||
| 1190 | } | ||
| 1191 | |||
| 1192 | static int | ||
| 1193 | malloc_init(void) | ||
| 1194 | { | ||
| 1195 | if (omalloc_init(&g_pool)) { | ||
| 1196 | _MALLOC_UNLOCK(); | ||
| 1197 | if (mopts.malloc_xmalloc) | ||
| 1198 | wrterror("out of memory"); | ||
| 1199 | errno = ENOMEM; | ||
| 1200 | return -1; | ||
| 1201 | } | ||
| 1202 | return 0; | ||
| 1203 | } | ||
| 1204 | |||
| 1205 | void * | ||
| 1206 | malloc(size_t size) | ||
| 1207 | { | ||
| 1208 | void *r; | ||
| 1209 | int saved_errno = errno; | ||
| 1210 | |||
| 1211 | _MALLOC_LOCK(); | ||
| 1212 | malloc_func = " in malloc():"; | ||
| 1213 | if (g_pool == NULL) { | ||
| 1214 | if (malloc_init() != 0) | ||
| 1215 | return NULL; | ||
| 1216 | } | ||
| 1217 | if (malloc_active++) { | ||
| 1218 | malloc_recurse(); | ||
| 1219 | return NULL; | ||
| 1220 | } | ||
| 1221 | r = omalloc(size, mopts.malloc_zero); | ||
| 1222 | malloc_active--; | ||
| 1223 | _MALLOC_UNLOCK(); | ||
| 1224 | if (r == NULL && mopts.malloc_xmalloc) { | ||
| 1225 | wrterror("out of memory"); | ||
| 1226 | errno = ENOMEM; | ||
| 1227 | } | ||
| 1228 | if (r != NULL) | ||
| 1229 | errno = saved_errno; | ||
| 1230 | return r; | ||
| 1231 | } | ||
| 1232 | |||
| 1233 | static void | ||
| 1234 | ofree(void *p) | ||
| 1235 | { | ||
| 1236 | struct region_info *r; | ||
| 1237 | size_t sz; | ||
| 1238 | |||
| 1239 | r = find(g_pool, p); | ||
| 1240 | if (r == NULL) { | ||
| 1241 | wrterror("bogus pointer (double free?)"); | ||
| 1242 | return; | ||
| 1243 | } | ||
| 1244 | REALSIZE(sz, r); | ||
| 1245 | if (sz > MALLOC_MAXCHUNK) { | ||
| 1246 | if (sz - mopts.malloc_guard >= MALLOC_PAGESIZE - | ||
| 1247 | MALLOC_LEEWAY) { | ||
| 1248 | if (r->p != p) { | ||
| 1249 | wrterror("bogus pointer"); | ||
| 1250 | return; | ||
| 1251 | } | ||
| 1252 | } else { | ||
| 1253 | #if notyetbecause_of_realloc | ||
| 1254 | /* shifted towards the end */ | ||
| 1255 | if (p != ((char *)r->p) + ((MALLOC_PAGESIZE - | ||
| 1256 | MALLOC_MINSIZE - sz - mopts.malloc_guard) & | ||
| 1257 | ~(MALLOC_MINSIZE-1))) { | ||
| 1258 | } | ||
| 1259 | #endif | ||
| 1260 | p = r->p; | ||
| 1261 | } | ||
| 1262 | if (mopts.malloc_guard) { | ||
| 1263 | if (sz < mopts.malloc_guard) | ||
| 1264 | wrterror("guard size"); | ||
| 1265 | if (!mopts.malloc_freeprot) { | ||
| 1266 | if (mprotect((char *)p + PAGEROUND(sz) - | ||
| 1267 | mopts.malloc_guard, mopts.malloc_guard, | ||
| 1268 | PROT_READ | PROT_WRITE)) | ||
| 1269 | wrterror("mprotect"); | ||
| 1270 | } | ||
| 1271 | malloc_guarded -= mopts.malloc_guard; | ||
| 1272 | } | ||
| 1273 | if (mopts.malloc_junk && !mopts.malloc_freeprot) | ||
| 1274 | memset(p, SOME_FREEJUNK, | ||
| 1275 | PAGEROUND(sz) - mopts.malloc_guard); | ||
| 1276 | unmap(g_pool, p, PAGEROUND(sz)); | ||
| 1277 | delete(g_pool, r); | ||
| 1278 | } else { | ||
| 1279 | void *tmp; | ||
| 1280 | int i; | ||
| 1281 | |||
| 1282 | if (mopts.malloc_junk && sz > 0) | ||
| 1283 | memset(p, SOME_FREEJUNK, sz); | ||
| 1284 | if (!mopts.malloc_freeprot) { | ||
| 1285 | i = getrnibble(); | ||
| 1286 | tmp = p; | ||
| 1287 | p = g_pool->delayed_chunks[i]; | ||
| 1288 | g_pool->delayed_chunks[i] = tmp; | ||
| 1289 | } | ||
| 1290 | if (p != NULL) { | ||
| 1291 | r = find(g_pool, p); | ||
| 1292 | if (r == NULL) { | ||
| 1293 | wrterror("bogus pointer (double free?)"); | ||
| 1294 | return; | ||
| 1295 | } | ||
| 1296 | free_bytes(g_pool, r, p); | ||
| 1297 | } | ||
| 1298 | } | ||
| 1299 | } | ||
| 1300 | |||
| 1301 | void | ||
| 1302 | free(void *ptr) | ||
| 1303 | { | ||
| 1304 | int saved_errno = errno; | ||
| 1305 | |||
| 1306 | /* This is legal. */ | ||
| 1307 | if (ptr == NULL) | ||
| 1308 | return; | ||
| 1309 | |||
| 1310 | _MALLOC_LOCK(); | ||
| 1311 | malloc_func = " in free():"; | ||
| 1312 | if (g_pool == NULL) { | ||
| 1313 | _MALLOC_UNLOCK(); | ||
| 1314 | wrterror("free() called before allocation"); | ||
| 1315 | return; | ||
| 1316 | } | ||
| 1317 | if (malloc_active++) { | ||
| 1318 | malloc_recurse(); | ||
| 1319 | return; | ||
| 1320 | } | ||
| 1321 | ofree(ptr); | ||
| 1322 | malloc_active--; | ||
| 1323 | _MALLOC_UNLOCK(); | ||
| 1324 | errno = saved_errno; | ||
| 1325 | } | ||
| 1326 | |||
| 1327 | |||
| 1328 | static void * | ||
| 1329 | orealloc(void *p, size_t newsz) | ||
| 1330 | { | ||
| 1331 | struct region_info *r; | ||
| 1332 | size_t oldsz, goldsz, gnewsz; | ||
| 1333 | void *q; | ||
| 1334 | |||
| 1335 | if (p == NULL) | ||
| 1336 | return omalloc(newsz, 0); | ||
| 1337 | |||
| 1338 | r = find(g_pool, p); | ||
| 1339 | if (r == NULL) { | ||
| 1340 | wrterror("bogus pointer (double free?)"); | ||
| 1341 | return NULL; | ||
| 1342 | } | ||
| 1343 | if (newsz >= SIZE_MAX - mopts.malloc_guard - MALLOC_PAGESIZE) { | ||
| 1344 | errno = ENOMEM; | ||
| 1345 | return NULL; | ||
| 1346 | } | ||
| 1347 | |||
| 1348 | REALSIZE(oldsz, r); | ||
| 1349 | goldsz = oldsz; | ||
| 1350 | if (oldsz > MALLOC_MAXCHUNK) { | ||
| 1351 | if (oldsz < mopts.malloc_guard) | ||
| 1352 | wrterror("guard size"); | ||
| 1353 | oldsz -= mopts.malloc_guard; | ||
| 1354 | } | ||
| 1355 | |||
| 1356 | gnewsz = newsz; | ||
| 1357 | if (gnewsz > MALLOC_MAXCHUNK) | ||
| 1358 | gnewsz += mopts.malloc_guard; | ||
| 1359 | |||
| 1360 | if (newsz > MALLOC_MAXCHUNK && oldsz > MALLOC_MAXCHUNK && p == r->p && | ||
| 1361 | !mopts.malloc_realloc) { | ||
| 1362 | size_t roldsz = PAGEROUND(goldsz); | ||
| 1363 | size_t rnewsz = PAGEROUND(gnewsz); | ||
| 1364 | |||
| 1365 | if (rnewsz > roldsz) { | ||
| 1366 | if (!mopts.malloc_guard) { | ||
| 1367 | STATS_INC(g_pool->cheap_realloc_tries); | ||
| 1368 | zapcacheregion(g_pool, p + roldsz); | ||
| 1369 | q = MMAPA(p + roldsz, rnewsz - roldsz); | ||
| 1370 | if (q == p + roldsz) { | ||
| 1371 | malloc_used += rnewsz - roldsz; | ||
| 1372 | if (mopts.malloc_junk) | ||
| 1373 | memset(q, SOME_JUNK, | ||
| 1374 | rnewsz - roldsz); | ||
| 1375 | r->size = newsz; | ||
| 1376 | STATS_INC(g_pool->cheap_reallocs); | ||
| 1377 | return p; | ||
| 1378 | } else if (q != MAP_FAILED) | ||
| 1379 | munmap(q, rnewsz - roldsz); | ||
| 1380 | } | ||
| 1381 | } else if (rnewsz < roldsz) { | ||
| 1382 | if (mopts.malloc_guard) { | ||
| 1383 | if (mprotect((char *)p + roldsz - | ||
| 1384 | mopts.malloc_guard, mopts.malloc_guard, | ||
| 1385 | PROT_READ | PROT_WRITE)) | ||
| 1386 | wrterror("mprotect"); | ||
| 1387 | if (mprotect((char *)p + rnewsz - | ||
| 1388 | mopts.malloc_guard, mopts.malloc_guard, | ||
| 1389 | PROT_NONE)) | ||
| 1390 | wrterror("mprotect"); | ||
| 1391 | } | ||
| 1392 | unmap(g_pool, (char *)p + rnewsz, roldsz - rnewsz); | ||
| 1393 | r->size = gnewsz; | ||
| 1394 | return p; | ||
| 1395 | } else { | ||
| 1396 | if (newsz > oldsz && mopts.malloc_junk) | ||
| 1397 | memset((char *)p + newsz, SOME_JUNK, | ||
| 1398 | rnewsz - mopts.malloc_guard - newsz); | ||
| 1399 | r->size = gnewsz; | ||
| 1400 | return p; | ||
| 1401 | } | ||
| 1402 | } | ||
| 1403 | if (newsz <= oldsz && newsz > oldsz / 2 && !mopts.malloc_realloc) { | ||
| 1404 | if (mopts.malloc_junk && newsz > 0) | ||
| 1405 | memset((char *)p + newsz, SOME_JUNK, oldsz - newsz); | ||
| 1406 | return p; | ||
| 1407 | } else if (newsz != oldsz || mopts.malloc_realloc) { | ||
| 1408 | q = omalloc(newsz, 0); | ||
| 1409 | if (q == NULL) | ||
| 1410 | return NULL; | ||
| 1411 | if (newsz != 0 && oldsz != 0) | ||
| 1412 | memcpy(q, p, oldsz < newsz ? oldsz : newsz); | ||
| 1413 | ofree(p); | ||
| 1414 | return q; | ||
| 1415 | } else | ||
| 1416 | return p; | ||
| 1417 | } | ||
| 1418 | |||
| 1419 | void * | ||
| 1420 | realloc(void *ptr, size_t size) | ||
| 1421 | { | ||
| 1422 | void *r; | ||
| 1423 | int saved_errno = errno; | ||
| 1424 | |||
| 1425 | _MALLOC_LOCK(); | ||
| 1426 | malloc_func = " in realloc():"; | ||
| 1427 | if (g_pool == NULL) { | ||
| 1428 | if (malloc_init() != 0) | ||
| 1429 | return NULL; | ||
| 1430 | } | ||
| 1431 | if (malloc_active++) { | ||
| 1432 | malloc_recurse(); | ||
| 1433 | return NULL; | ||
| 1434 | } | ||
| 1435 | r = orealloc(ptr, size); | ||
| 1436 | |||
| 1437 | malloc_active--; | ||
| 1438 | _MALLOC_UNLOCK(); | ||
| 1439 | if (r == NULL && mopts.malloc_xmalloc) { | ||
| 1440 | wrterror("out of memory"); | ||
| 1441 | errno = ENOMEM; | ||
| 1442 | } | ||
| 1443 | if (r != NULL) | ||
| 1444 | errno = saved_errno; | ||
| 1445 | return r; | ||
| 1446 | } | ||
| 1447 | |||
| 1448 | |||
| 1449 | #define MUL_NO_OVERFLOW (1UL << (sizeof(size_t) * 4)) | ||
| 1450 | |||
| 1451 | void * | ||
| 1452 | calloc(size_t nmemb, size_t size) | ||
| 1453 | { | ||
| 1454 | void *r; | ||
| 1455 | int saved_errno = errno; | ||
| 1456 | |||
| 1457 | _MALLOC_LOCK(); | ||
| 1458 | malloc_func = " in calloc():"; | ||
| 1459 | if (g_pool == NULL) { | ||
| 1460 | if (malloc_init() != 0) | ||
| 1461 | return NULL; | ||
| 1462 | } | ||
| 1463 | if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) && | ||
| 1464 | nmemb > 0 && SIZE_MAX / nmemb < size) { | ||
| 1465 | _MALLOC_UNLOCK(); | ||
| 1466 | if (mopts.malloc_xmalloc) | ||
| 1467 | wrterror("out of memory"); | ||
| 1468 | errno = ENOMEM; | ||
| 1469 | return NULL; | ||
| 1470 | } | ||
| 1471 | |||
| 1472 | if (malloc_active++) { | ||
| 1473 | malloc_recurse(); | ||
| 1474 | return NULL; | ||
| 1475 | } | ||
| 1476 | |||
| 1477 | size *= nmemb; | ||
| 1478 | r = omalloc(size, 1); | ||
| 1479 | |||
| 1480 | malloc_active--; | ||
| 1481 | _MALLOC_UNLOCK(); | ||
| 1482 | if (r == NULL && mopts.malloc_xmalloc) { | ||
| 1483 | wrterror("out of memory"); | ||
| 1484 | errno = ENOMEM; | ||
| 1485 | } | ||
| 1486 | if (r != NULL) | ||
| 1487 | errno = saved_errno; | ||
| 1488 | return r; | ||
| 1489 | } | ||
| 1490 | |||
| 1491 | int | ||
| 1492 | posix_memalign(void **memptr, size_t alignment, size_t size) | ||
| 1493 | { | ||
| 1494 | void *result; | ||
| 1495 | |||
| 1496 | /* Make sure that alignment is a large enough power of 2. */ | ||
| 1497 | if (((alignment - 1) & alignment) != 0 || alignment < sizeof(void *) || | ||
| 1498 | alignment > MALLOC_PAGESIZE) | ||
| 1499 | return EINVAL; | ||
| 1500 | |||
| 1501 | /* | ||
| 1502 | * max(size, alignment) is enough to assure the requested alignment, | ||
| 1503 | * since the allocator always allocates power-of-two blocks. | ||
| 1504 | */ | ||
| 1505 | if (size < alignment) | ||
| 1506 | size = alignment; | ||
| 1507 | result = malloc(size); | ||
| 1508 | |||
| 1509 | if (result == NULL) | ||
| 1510 | return ENOMEM; | ||
| 1511 | |||
| 1512 | *memptr = result; | ||
| 1513 | return 0; | ||
| 1514 | } | ||
| 1515 | |||
