1 /* $OpenBSD: malloc.c,v 1.283 2023/05/10 07:58:06 otto Exp $ */ 2 /* 3 * Copyright (c) 2008, 2010, 2011, 2016, 2023 Otto Moerbeek <otto@drijf.net> 4 * Copyright (c) 2012 Matthew Dempsky <matthew@openbsd.org> 5 * Copyright (c) 2008 Damien Miller <djm@openbsd.org> 6 * Copyright (c) 2000 Poul-Henning Kamp <phk@FreeBSD.org> 7 * 8 * Permission to use, copy, modify, and distribute this software for any 9 * purpose with or without fee is hereby granted, provided that the above 10 * copyright notice and this permission notice appear in all copies. 11 * 12 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 13 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 14 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 15 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 16 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 17 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 18 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 19 */ 20 21 /* 22 * If we meet some day, and you think this stuff is worth it, you 23 * can buy me a beer in return. Poul-Henning Kamp 24 */ 25 26 #ifndef MALLOC_SMALL 27 #define MALLOC_STATS 28 #endif 29 30 #include <sys/types.h> 31 #include <sys/queue.h> 32 #include <sys/mman.h> 33 #include <sys/sysctl.h> 34 #include <uvm/uvmexp.h> 35 #include <errno.h> 36 #include <stdarg.h> 37 #include <stdint.h> 38 #include <stdio.h> 39 #include <stdlib.h> 40 #include <string.h> 41 #include <unistd.h> 42 43 #ifdef MALLOC_STATS 44 #include <sys/tree.h> 45 #include <sys/ktrace.h> 46 #include <dlfcn.h> 47 #endif 48 49 #include "thread_private.h" 50 #include <tib.h> 51 52 #define MALLOC_PAGESHIFT _MAX_PAGE_SHIFT 53 54 #define MALLOC_MINSHIFT 4 55 #define MALLOC_MAXSHIFT (MALLOC_PAGESHIFT - 1) 56 #define MALLOC_PAGESIZE (1UL << MALLOC_PAGESHIFT) 57 #define MALLOC_MINSIZE (1UL << MALLOC_MINSHIFT) 58 #define MALLOC_PAGEMASK (MALLOC_PAGESIZE - 1) 59 #define MASK_POINTER(p) ((void *)(((uintptr_t)(p)) & ~MALLOC_PAGEMASK)) 60 61 #define MALLOC_MAXCHUNK (1 << MALLOC_MAXSHIFT) 62 #define MALLOC_MAXCACHE 256 63 #define MALLOC_DELAYED_CHUNK_MASK 15 64 #ifdef MALLOC_STATS 65 #define MALLOC_INITIAL_REGIONS 512 66 #else 67 #define MALLOC_INITIAL_REGIONS (MALLOC_PAGESIZE / sizeof(struct region_info)) 68 #endif 69 #define MALLOC_DEFAULT_CACHE 64 70 #define MALLOC_CHUNK_LISTS 4 71 #define CHUNK_CHECK_LENGTH 32 72 73 #define B2SIZE(b) ((b) * MALLOC_MINSIZE) 74 #define B2ALLOC(b) ((b) == 0 ? MALLOC_MINSIZE : \ 75 (b) * MALLOC_MINSIZE) 76 #define BUCKETS (MALLOC_MAXCHUNK / MALLOC_MINSIZE) 77 78 /* 79 * We move allocations between half a page and a whole page towards the end, 80 * subject to alignment constraints. This is the extra headroom we allow. 81 * Set to zero to be the most strict. 82 */ 83 #define MALLOC_LEEWAY 0 84 #define MALLOC_MOVE_COND(sz) ((sz) - mopts.malloc_guard < \ 85 MALLOC_PAGESIZE - MALLOC_LEEWAY) 86 #define MALLOC_MOVE(p, sz) (((char *)(p)) + \ 87 ((MALLOC_PAGESIZE - MALLOC_LEEWAY - \ 88 ((sz) - mopts.malloc_guard)) & \ 89 ~(MALLOC_MINSIZE - 1))) 90 91 #define PAGEROUND(x) (((x) + (MALLOC_PAGEMASK)) & ~MALLOC_PAGEMASK) 92 93 /* 94 * What to use for Junk. This is the byte value we use to fill with 95 * when the 'J' option is enabled. Use SOME_JUNK right after alloc, 96 * and SOME_FREEJUNK right before free. 97 */ 98 #define SOME_JUNK 0xdb /* deadbeef */ 99 #define SOME_FREEJUNK 0xdf /* dead, free */ 100 #define SOME_FREEJUNK_ULL 0xdfdfdfdfdfdfdfdfULL 101 102 #define MMAP(sz,f) mmap(NULL, (sz), PROT_READ | PROT_WRITE, \ 103 MAP_ANON | MAP_PRIVATE | (f), -1, 0) 104 105 #define MMAPNONE(sz,f) mmap(NULL, (sz), PROT_NONE, \ 106 MAP_ANON | MAP_PRIVATE | (f), -1, 0) 107 108 #define MMAPA(a,sz,f) mmap((a), (sz), PROT_READ | PROT_WRITE, \ 109 MAP_ANON | MAP_PRIVATE | (f), -1, 0) 110 111 struct region_info { 112 void *p; /* page; low bits used to mark chunks */ 113 uintptr_t size; /* size for pages, or chunk_info pointer */ 114 #ifdef MALLOC_STATS 115 void *f; /* where allocated from */ 116 #endif 117 }; 118 119 LIST_HEAD(chunk_head, chunk_info); 120 121 /* 122 * Two caches, one for "small" regions, one for "big". 123 * Small cache is an array per size, big cache is one array with different 124 * sized regions 125 */ 126 #define MAX_SMALLCACHEABLE_SIZE 32 127 #define MAX_BIGCACHEABLE_SIZE 512 128 /* If the total # of pages is larger than this, evict before inserting */ 129 #define BIGCACHE_FILL(sz) (MAX_BIGCACHEABLE_SIZE * (sz) / 4) 130 131 struct smallcache { 132 void **pages; 133 ushort length; 134 ushort max; 135 }; 136 137 struct bigcache { 138 void *page; 139 size_t psize; 140 }; 141 142 struct dir_info { 143 u_int32_t canary1; 144 int active; /* status of malloc */ 145 struct region_info *r; /* region slots */ 146 size_t regions_total; /* number of region slots */ 147 size_t regions_free; /* number of free slots */ 148 size_t rbytesused; /* random bytes used */ 149 char *func; /* current function */ 150 int malloc_junk; /* junk fill? */ 151 int mmap_flag; /* extra flag for mmap */ 152 int mutex; 153 int malloc_mt; /* multi-threaded mode? */ 154 /* lists of free chunk info structs */ 155 struct chunk_head chunk_info_list[BUCKETS + 1]; 156 /* lists of chunks with free slots */ 157 struct chunk_head chunk_dir[BUCKETS + 1][MALLOC_CHUNK_LISTS]; 158 /* delayed free chunk slots */ 159 void *delayed_chunks[MALLOC_DELAYED_CHUNK_MASK + 1]; 160 u_char rbytes[32]; /* random bytes */ 161 /* free pages cache */ 162 struct smallcache smallcache[MAX_SMALLCACHEABLE_SIZE]; 163 size_t bigcache_used; 164 size_t bigcache_size; 165 struct bigcache *bigcache; 166 void *chunk_pages; 167 size_t chunk_pages_used; 168 #ifdef MALLOC_STATS 169 size_t inserts; 170 size_t insert_collisions; 171 size_t finds; 172 size_t find_collisions; 173 size_t deletes; 174 size_t delete_moves; 175 size_t cheap_realloc_tries; 176 size_t cheap_reallocs; 177 size_t malloc_used; /* bytes allocated */ 178 size_t malloc_guarded; /* bytes used for guards */ 179 size_t pool_searches; /* searches for pool */ 180 size_t other_pool; /* searches in other pool */ 181 #define STATS_ADD(x,y) ((x) += (y)) 182 #define STATS_SUB(x,y) ((x) -= (y)) 183 #define STATS_INC(x) ((x)++) 184 #define STATS_ZERO(x) ((x) = 0) 185 #define STATS_SETF(x,y) ((x)->f = (y)) 186 #else 187 #define STATS_ADD(x,y) /* nothing */ 188 #define STATS_SUB(x,y) /* nothing */ 189 #define STATS_INC(x) /* nothing */ 190 #define STATS_ZERO(x) /* nothing */ 191 #define STATS_SETF(x,y) /* nothing */ 192 #endif /* MALLOC_STATS */ 193 u_int32_t canary2; 194 }; 195 196 static void unmap(struct dir_info *d, void *p, size_t sz, size_t clear); 197 198 /* 199 * This structure describes a page worth of chunks. 200 * 201 * How many bits per u_short in the bitmap 202 */ 203 #define MALLOC_BITS (NBBY * sizeof(u_short)) 204 struct chunk_info { 205 LIST_ENTRY(chunk_info) entries; 206 void *page; /* pointer to the page */ 207 u_short canary; 208 u_short bucket; 209 u_short free; /* how many free chunks */ 210 u_short total; /* how many chunks */ 211 u_short offset; /* requested size table offset */ 212 u_short bits[1]; /* which chunks are free */ 213 }; 214 215 struct malloc_readonly { 216 /* Main bookkeeping information */ 217 struct dir_info *malloc_pool[_MALLOC_MUTEXES]; 218 u_int malloc_mutexes; /* how much in actual use? */ 219 int malloc_freecheck; /* Extensive double free check */ 220 int malloc_freeunmap; /* mprotect free pages PROT_NONE? */ 221 int def_malloc_junk; /* junk fill? */ 222 int malloc_realloc; /* always realloc? */ 223 int malloc_xmalloc; /* xmalloc behaviour? */ 224 u_int chunk_canaries; /* use canaries after chunks? */ 225 int internal_funcs; /* use better recallocarray/freezero? */ 226 u_int def_maxcache; /* free pages we cache */ 227 u_int junk_loc; /* variation in location of junk */ 228 size_t malloc_guard; /* use guard pages after allocations? */ 229 #ifdef MALLOC_STATS 230 int malloc_stats; /* dump leak report at end */ 231 int malloc_verbose; /* dump verbose statistics at end */ 232 #define DO_STATS mopts.malloc_stats 233 #else 234 #define DO_STATS 0 235 #endif 236 u_int32_t malloc_canary; /* Matched against ones in pool */ 237 }; 238 239 240 /* This object is mapped PROT_READ after initialisation to prevent tampering */ 241 static union { 242 struct malloc_readonly mopts; 243 u_char _pad[MALLOC_PAGESIZE]; 244 } malloc_readonly __attribute__((aligned(MALLOC_PAGESIZE))) 245 __attribute__((section(".openbsd.mutable"))); 246 #define mopts malloc_readonly.mopts 247 248 char *malloc_options; /* compile-time options */ 249 250 static __dead void wrterror(struct dir_info *d, char *msg, ...) 251 __attribute__((__format__ (printf, 2, 3))); 252 253 #ifdef MALLOC_STATS 254 void malloc_dump(void); 255 PROTO_NORMAL(malloc_dump); 256 static void malloc_exit(void); 257 #endif 258 #define CALLER (DO_STATS ? __builtin_return_address(0) : NULL) 259 260 /* low bits of r->p determine size: 0 means >= page size and r->size holding 261 * real size, otherwise low bits is the bucket + 1 262 */ 263 #define REALSIZE(sz, r) \ 264 (sz) = (uintptr_t)(r)->p & MALLOC_PAGEMASK, \ 265 (sz) = ((sz) == 0 ? (r)->size : B2SIZE((sz) - 1)) 266 267 static inline size_t 268 hash(void *p) 269 { 270 size_t sum; 271 uintptr_t u; 272 273 u = (uintptr_t)p >> MALLOC_PAGESHIFT; 274 sum = u; 275 sum = (sum << 7) - sum + (u >> 16); 276 #ifdef __LP64__ 277 sum = (sum << 7) - sum + (u >> 32); 278 sum = (sum << 7) - sum + (u >> 48); 279 #endif 280 return sum; 281 } 282 283 static inline struct dir_info * 284 getpool(void) 285 { 286 if (mopts.malloc_pool[1] == NULL || !mopts.malloc_pool[1]->malloc_mt) 287 return mopts.malloc_pool[1]; 288 else /* first one reserved for special pool */ 289 return mopts.malloc_pool[1 + TIB_GET()->tib_tid % 290 (mopts.malloc_mutexes - 1)]; 291 } 292 293 static __dead void 294 wrterror(struct dir_info *d, char *msg, ...) 295 { 296 int saved_errno = errno; 297 va_list ap; 298 299 dprintf(STDERR_FILENO, "%s(%d) in %s(): ", __progname, 300 getpid(), (d != NULL && d->func) ? d->func : "unknown"); 301 va_start(ap, msg); 302 vdprintf(STDERR_FILENO, msg, ap); 303 va_end(ap); 304 dprintf(STDERR_FILENO, "\n"); 305 306 #ifdef MALLOC_STATS 307 if (DO_STATS && mopts.malloc_verbose) 308 malloc_dump(); 309 #endif 310 311 errno = saved_errno; 312 313 abort(); 314 } 315 316 static void 317 rbytes_init(struct dir_info *d) 318 { 319 arc4random_buf(d->rbytes, sizeof(d->rbytes)); 320 /* add 1 to account for using d->rbytes[0] */ 321 d->rbytesused = 1 + d->rbytes[0] % (sizeof(d->rbytes) / 2); 322 } 323 324 static inline u_char 325 getrbyte(struct dir_info *d) 326 { 327 u_char x; 328 329 if (d->rbytesused >= sizeof(d->rbytes)) 330 rbytes_init(d); 331 x = d->rbytes[d->rbytesused++]; 332 return x; 333 } 334 335 static void 336 omalloc_parseopt(char opt) 337 { 338 switch (opt) { 339 case '+': 340 mopts.malloc_mutexes <<= 1; 341 if (mopts.malloc_mutexes > _MALLOC_MUTEXES) 342 mopts.malloc_mutexes = _MALLOC_MUTEXES; 343 break; 344 case '-': 345 mopts.malloc_mutexes >>= 1; 346 if (mopts.malloc_mutexes < 2) 347 mopts.malloc_mutexes = 2; 348 break; 349 case '>': 350 mopts.def_maxcache <<= 1; 351 if (mopts.def_maxcache > MALLOC_MAXCACHE) 352 mopts.def_maxcache = MALLOC_MAXCACHE; 353 break; 354 case '<': 355 mopts.def_maxcache >>= 1; 356 break; 357 case 'c': 358 mopts.chunk_canaries = 0; 359 break; 360 case 'C': 361 mopts.chunk_canaries = 1; 362 break; 363 #ifdef MALLOC_STATS 364 case 'd': 365 mopts.malloc_stats = 0; 366 break; 367 case 'D': 368 mopts.malloc_stats = 1; 369 break; 370 #endif /* MALLOC_STATS */ 371 case 'f': 372 mopts.malloc_freecheck = 0; 373 mopts.malloc_freeunmap = 0; 374 break; 375 case 'F': 376 mopts.malloc_freecheck = 1; 377 mopts.malloc_freeunmap = 1; 378 break; 379 case 'g': 380 mopts.malloc_guard = 0; 381 break; 382 case 'G': 383 mopts.malloc_guard = MALLOC_PAGESIZE; 384 break; 385 case 'j': 386 if (mopts.def_malloc_junk > 0) 387 mopts.def_malloc_junk--; 388 break; 389 case 'J': 390 if (mopts.def_malloc_junk < 2) 391 mopts.def_malloc_junk++; 392 break; 393 case 'r': 394 mopts.malloc_realloc = 0; 395 break; 396 case 'R': 397 mopts.malloc_realloc = 1; 398 break; 399 case 'u': 400 mopts.malloc_freeunmap = 0; 401 break; 402 case 'U': 403 mopts.malloc_freeunmap = 1; 404 break; 405 #ifdef MALLOC_STATS 406 case 'v': 407 mopts.malloc_verbose = 0; 408 break; 409 case 'V': 410 mopts.malloc_verbose = 1; 411 break; 412 #endif /* MALLOC_STATS */ 413 case 'x': 414 mopts.malloc_xmalloc = 0; 415 break; 416 case 'X': 417 mopts.malloc_xmalloc = 1; 418 break; 419 default: 420 dprintf(STDERR_FILENO, "malloc() warning: " 421 "unknown char in MALLOC_OPTIONS\n"); 422 break; 423 } 424 } 425 426 static void 427 omalloc_init(void) 428 { 429 char *p, *q, b[16]; 430 int i, j; 431 const int mib[2] = { CTL_VM, VM_MALLOC_CONF }; 432 size_t sb; 433 434 /* 435 * Default options 436 */ 437 mopts.malloc_mutexes = 8; 438 mopts.def_malloc_junk = 1; 439 mopts.def_maxcache = MALLOC_DEFAULT_CACHE; 440 441 for (i = 0; i < 3; i++) { 442 switch (i) { 443 case 0: 444 sb = sizeof(b); 445 j = sysctl(mib, 2, b, &sb, NULL, 0); 446 if (j != 0) 447 continue; 448 p = b; 449 break; 450 case 1: 451 if (issetugid() == 0) 452 p = getenv("MALLOC_OPTIONS"); 453 else 454 continue; 455 break; 456 case 2: 457 p = malloc_options; 458 break; 459 default: 460 p = NULL; 461 } 462 463 for (; p != NULL && *p != '\0'; p++) { 464 switch (*p) { 465 case 'S': 466 for (q = "CFGJ"; *q != '\0'; q++) 467 omalloc_parseopt(*q); 468 mopts.def_maxcache = 0; 469 break; 470 case 's': 471 for (q = "cfgj"; *q != '\0'; q++) 472 omalloc_parseopt(*q); 473 mopts.def_maxcache = MALLOC_DEFAULT_CACHE; 474 break; 475 default: 476 omalloc_parseopt(*p); 477 break; 478 } 479 } 480 } 481 482 #ifdef MALLOC_STATS 483 if (DO_STATS && (atexit(malloc_exit) == -1)) { 484 dprintf(STDERR_FILENO, "malloc() warning: atexit(2) failed." 485 " Will not be able to dump stats on exit\n"); 486 } 487 #endif 488 489 while ((mopts.malloc_canary = arc4random()) == 0) 490 ; 491 mopts.junk_loc = arc4random(); 492 if (mopts.chunk_canaries) 493 do { 494 mopts.chunk_canaries = arc4random(); 495 } while ((u_char)mopts.chunk_canaries == 0 || 496 (u_char)mopts.chunk_canaries == SOME_FREEJUNK); 497 } 498 499 static void 500 omalloc_poolinit(struct dir_info *d, int mmap_flag) 501 { 502 int i, j; 503 504 d->r = NULL; 505 d->rbytesused = sizeof(d->rbytes); 506 d->regions_free = d->regions_total = 0; 507 for (i = 0; i <= BUCKETS; i++) { 508 LIST_INIT(&d->chunk_info_list[i]); 509 for (j = 0; j < MALLOC_CHUNK_LISTS; j++) 510 LIST_INIT(&d->chunk_dir[i][j]); 511 } 512 d->mmap_flag = mmap_flag; 513 d->malloc_junk = mopts.def_malloc_junk; 514 d->canary1 = mopts.malloc_canary ^ (u_int32_t)(uintptr_t)d; 515 d->canary2 = ~d->canary1; 516 } 517 518 static int 519 omalloc_grow(struct dir_info *d) 520 { 521 size_t newtotal; 522 size_t newsize; 523 size_t mask; 524 size_t i, oldpsz; 525 struct region_info *p; 526 527 if (d->regions_total > SIZE_MAX / sizeof(struct region_info) / 2) 528 return 1; 529 530 newtotal = d->regions_total == 0 ? MALLOC_INITIAL_REGIONS : 531 d->regions_total * 2; 532 newsize = PAGEROUND(newtotal * sizeof(struct region_info)); 533 mask = newtotal - 1; 534 535 /* Don't use cache here, we don't want user uaf touch this */ 536 p = MMAP(newsize, d->mmap_flag); 537 if (p == MAP_FAILED) 538 return 1; 539 540 STATS_ADD(d->malloc_used, newsize); 541 STATS_ZERO(d->inserts); 542 STATS_ZERO(d->insert_collisions); 543 for (i = 0; i < d->regions_total; i++) { 544 void *q = d->r[i].p; 545 if (q != NULL) { 546 size_t index = hash(q) & mask; 547 STATS_INC(d->inserts); 548 while (p[index].p != NULL) { 549 index = (index - 1) & mask; 550 STATS_INC(d->insert_collisions); 551 } 552 p[index] = d->r[i]; 553 } 554 } 555 556 if (d->regions_total > 0) { 557 oldpsz = PAGEROUND(d->regions_total * sizeof(struct region_info)); 558 /* clear to avoid meta info ending up in the cache */ 559 unmap(d, d->r, oldpsz, oldpsz); 560 } 561 d->regions_free += newtotal - d->regions_total; 562 d->regions_total = newtotal; 563 d->r = p; 564 return 0; 565 } 566 567 /* 568 * The hashtable uses the assumption that p is never NULL. This holds since 569 * non-MAP_FIXED mappings with hint 0 start at BRKSIZ. 570 */ 571 static int 572 insert(struct dir_info *d, void *p, size_t sz, void *f) 573 { 574 size_t index; 575 size_t mask; 576 void *q; 577 578 if (d->regions_free * 4 < d->regions_total || d->regions_total == 0) { 579 if (omalloc_grow(d)) 580 return 1; 581 } 582 mask = d->regions_total - 1; 583 index = hash(p) & mask; 584 q = d->r[index].p; 585 STATS_INC(d->inserts); 586 while (q != NULL) { 587 index = (index - 1) & mask; 588 q = d->r[index].p; 589 STATS_INC(d->insert_collisions); 590 } 591 d->r[index].p = p; 592 d->r[index].size = sz; 593 STATS_SETF(&d->r[index], f); 594 d->regions_free--; 595 return 0; 596 } 597 598 static struct region_info * 599 find(struct dir_info *d, void *p) 600 { 601 size_t index; 602 size_t mask = d->regions_total - 1; 603 void *q, *r; 604 605 if (mopts.malloc_canary != (d->canary1 ^ (u_int32_t)(uintptr_t)d) || 606 d->canary1 != ~d->canary2) 607 wrterror(d, "internal struct corrupt"); 608 if (d->r == NULL) 609 return NULL; 610 p = MASK_POINTER(p); 611 index = hash(p) & mask; 612 r = d->r[index].p; 613 q = MASK_POINTER(r); 614 STATS_INC(d->finds); 615 while (q != p && r != NULL) { 616 index = (index - 1) & mask; 617 r = d->r[index].p; 618 q = MASK_POINTER(r); 619 STATS_INC(d->find_collisions); 620 } 621 return (q == p && r != NULL) ? &d->r[index] : NULL; 622 } 623 624 static void 625 delete(struct dir_info *d, struct region_info *ri) 626 { 627 /* algorithm R, Knuth Vol III section 6.4 */ 628 size_t mask = d->regions_total - 1; 629 size_t i, j, r; 630 631 if (d->regions_total & (d->regions_total - 1)) 632 wrterror(d, "regions_total not 2^x"); 633 d->regions_free++; 634 STATS_INC(d->deletes); 635 636 i = ri - d->r; 637 for (;;) { 638 d->r[i].p = NULL; 639 d->r[i].size = 0; 640 j = i; 641 for (;;) { 642 i = (i - 1) & mask; 643 if (d->r[i].p == NULL) 644 return; 645 r = hash(d->r[i].p) & mask; 646 if ((i <= r && r < j) || (r < j && j < i) || 647 (j < i && i <= r)) 648 continue; 649 d->r[j] = d->r[i]; 650 STATS_INC(d->delete_moves); 651 break; 652 } 653 654 } 655 } 656 657 static inline void 658 junk_free(int junk, void *p, size_t sz) 659 { 660 size_t i, step = 1; 661 uint64_t *lp = p; 662 663 if (junk == 0 || sz == 0) 664 return; 665 sz /= sizeof(uint64_t); 666 if (junk == 1) { 667 if (sz > MALLOC_PAGESIZE / sizeof(uint64_t)) 668 sz = MALLOC_PAGESIZE / sizeof(uint64_t); 669 step = sz / 4; 670 if (step == 0) 671 step = 1; 672 } 673 /* Do not always put the free junk bytes in the same spot. 674 There is modulo bias here, but we ignore that. */ 675 for (i = mopts.junk_loc % step; i < sz; i += step) 676 lp[i] = SOME_FREEJUNK_ULL; 677 } 678 679 static inline void 680 validate_junk(struct dir_info *pool, void *p, size_t sz) 681 { 682 size_t i, step = 1; 683 uint64_t *lp = p; 684 685 if (pool->malloc_junk == 0 || sz == 0) 686 return; 687 sz /= sizeof(uint64_t); 688 if (pool->malloc_junk == 1) { 689 if (sz > MALLOC_PAGESIZE / sizeof(uint64_t)) 690 sz = MALLOC_PAGESIZE / sizeof(uint64_t); 691 step = sz / 4; 692 if (step == 0) 693 step = 1; 694 } 695 /* see junk_free */ 696 for (i = mopts.junk_loc % step; i < sz; i += step) { 697 if (lp[i] != SOME_FREEJUNK_ULL) 698 wrterror(pool, "write after free %p", p); 699 } 700 } 701 702 703 /* 704 * Cache maintenance. 705 * Opposed to the regular region data structure, the sizes in the 706 * cache are in MALLOC_PAGESIZE units. 707 */ 708 static void 709 unmap(struct dir_info *d, void *p, size_t sz, size_t clear) 710 { 711 size_t psz = sz >> MALLOC_PAGESHIFT; 712 void *r; 713 u_short i; 714 struct smallcache *cache; 715 716 if (sz != PAGEROUND(sz) || psz == 0) 717 wrterror(d, "munmap round"); 718 719 if (d->bigcache_size > 0 && psz > MAX_SMALLCACHEABLE_SIZE && 720 psz <= MAX_BIGCACHEABLE_SIZE) { 721 u_short base = getrbyte(d); 722 u_short j; 723 724 /* don't look through all slots */ 725 for (j = 0; j < d->bigcache_size / 4; j++) { 726 i = (base + j) & (d->bigcache_size - 1); 727 if (d->bigcache_used < 728 BIGCACHE_FILL(d->bigcache_size)) { 729 if (d->bigcache[i].psize == 0) 730 break; 731 } else { 732 if (d->bigcache[i].psize != 0) 733 break; 734 } 735 } 736 /* if we didn't find a preferred slot, use random one */ 737 if (d->bigcache[i].psize != 0) { 738 size_t tmp; 739 740 r = d->bigcache[i].page; 741 d->bigcache_used -= d->bigcache[i].psize; 742 tmp = d->bigcache[i].psize << MALLOC_PAGESHIFT; 743 if (!mopts.malloc_freeunmap) 744 validate_junk(d, r, tmp); 745 if (munmap(r, tmp)) 746 wrterror(d, "munmap %p", r); 747 STATS_SUB(d->malloc_used, tmp); 748 } 749 750 if (clear > 0) 751 explicit_bzero(p, clear); 752 if (mopts.malloc_freeunmap) { 753 if (mprotect(p, sz, PROT_NONE)) 754 wrterror(d, "mprotect %p", r); 755 } else 756 junk_free(d->malloc_junk, p, sz); 757 d->bigcache[i].page = p; 758 d->bigcache[i].psize = psz; 759 d->bigcache_used += psz; 760 return; 761 } 762 if (psz > MAX_SMALLCACHEABLE_SIZE || d->smallcache[psz - 1].max == 0) { 763 if (munmap(p, sz)) 764 wrterror(d, "munmap %p", p); 765 STATS_SUB(d->malloc_used, sz); 766 return; 767 } 768 cache = &d->smallcache[psz - 1]; 769 if (cache->length == cache->max) { 770 int fresh; 771 /* use a random slot */ 772 i = getrbyte(d) & (cache->max - 1); 773 r = cache->pages[i]; 774 fresh = (uintptr_t)r & 1; 775 *(uintptr_t*)&r &= ~1ULL; 776 if (!fresh && !mopts.malloc_freeunmap) 777 validate_junk(d, r, sz); 778 if (munmap(r, sz)) 779 wrterror(d, "munmap %p", r); 780 STATS_SUB(d->malloc_used, sz); 781 cache->length--; 782 } else 783 i = cache->length; 784 785 /* fill slot */ 786 if (clear > 0) 787 explicit_bzero(p, clear); 788 if (mopts.malloc_freeunmap) 789 mprotect(p, sz, PROT_NONE); 790 else 791 junk_free(d->malloc_junk, p, sz); 792 cache->pages[i] = p; 793 cache->length++; 794 } 795 796 static void * 797 map(struct dir_info *d, size_t sz, int zero_fill) 798 { 799 size_t psz = sz >> MALLOC_PAGESHIFT; 800 u_short i; 801 void *p; 802 struct smallcache *cache; 803 804 if (mopts.malloc_canary != (d->canary1 ^ (u_int32_t)(uintptr_t)d) || 805 d->canary1 != ~d->canary2) 806 wrterror(d, "internal struct corrupt"); 807 if (sz != PAGEROUND(sz) || psz == 0) 808 wrterror(d, "map round"); 809 810 811 if (d->bigcache_size > 0 && psz > MAX_SMALLCACHEABLE_SIZE && 812 psz <= MAX_BIGCACHEABLE_SIZE) { 813 size_t base = getrbyte(d); 814 size_t cached = d->bigcache_used; 815 ushort j; 816 817 for (j = 0; j < d->bigcache_size && cached >= psz; j++) { 818 i = (j + base) & (d->bigcache_size - 1); 819 if (d->bigcache[i].psize == psz) { 820 p = d->bigcache[i].page; 821 d->bigcache_used -= psz; 822 d->bigcache[i].page = NULL; 823 d->bigcache[i].psize = 0; 824 825 if (!mopts.malloc_freeunmap) 826 validate_junk(d, p, sz); 827 if (mopts.malloc_freeunmap) 828 mprotect(p, sz, PROT_READ | PROT_WRITE); 829 if (zero_fill) 830 memset(p, 0, sz); 831 else if (mopts.malloc_freeunmap) 832 junk_free(d->malloc_junk, p, sz); 833 return p; 834 } 835 cached -= d->bigcache[i].psize; 836 } 837 } 838 if (psz <= MAX_SMALLCACHEABLE_SIZE && d->smallcache[psz - 1].max > 0) { 839 cache = &d->smallcache[psz - 1]; 840 if (cache->length > 0) { 841 int fresh; 842 if (cache->length == 1) 843 p = cache->pages[--cache->length]; 844 else { 845 i = getrbyte(d) % cache->length; 846 p = cache->pages[i]; 847 cache->pages[i] = cache->pages[--cache->length]; 848 } 849 /* check if page was not junked, i.e. "fresh 850 we use the lsb of the pointer for that */ 851 fresh = (uintptr_t)p & 1UL; 852 *(uintptr_t*)&p &= ~1UL; 853 if (!fresh && !mopts.malloc_freeunmap) 854 validate_junk(d, p, sz); 855 if (mopts.malloc_freeunmap) 856 mprotect(p, sz, PROT_READ | PROT_WRITE); 857 if (zero_fill) 858 memset(p, 0, sz); 859 else if (mopts.malloc_freeunmap) 860 junk_free(d->malloc_junk, p, sz); 861 return p; 862 } 863 if (psz <= 1) { 864 p = MMAP(cache->max * sz, d->mmap_flag); 865 if (p != MAP_FAILED) { 866 STATS_ADD(d->malloc_used, cache->max * sz); 867 cache->length = cache->max - 1; 868 for (i = 0; i < cache->max - 1; i++) { 869 void *q = (char*)p + i * sz; 870 cache->pages[i] = q; 871 /* mark pointer in slot as not junked */ 872 *(uintptr_t*)&cache->pages[i] |= 1UL; 873 } 874 if (mopts.malloc_freeunmap) 875 mprotect(p, (cache->max - 1) * sz, 876 PROT_NONE); 877 p = (char*)p + (cache->max - 1) * sz; 878 /* zero fill not needed, freshly mmapped */ 879 return p; 880 } 881 } 882 883 } 884 p = MMAP(sz, d->mmap_flag); 885 if (p != MAP_FAILED) 886 STATS_ADD(d->malloc_used, sz); 887 /* zero fill not needed */ 888 return p; 889 } 890 891 static void 892 init_chunk_info(struct dir_info *d, struct chunk_info *p, u_int bucket) 893 { 894 u_int i; 895 896 p->bucket = bucket; 897 p->total = p->free = MALLOC_PAGESIZE / B2ALLOC(bucket); 898 p->offset = bucket == 0 ? 0xdead : howmany(p->total, MALLOC_BITS); 899 p->canary = (u_short)d->canary1; 900 901 /* set all valid bits in the bitmap */ 902 i = p->total - 1; 903 memset(p->bits, 0xff, sizeof(p->bits[0]) * (i / MALLOC_BITS)); 904 p->bits[i / MALLOC_BITS] = (2U << (i % MALLOC_BITS)) - 1; 905 } 906 907 static struct chunk_info * 908 alloc_chunk_info(struct dir_info *d, u_int bucket) 909 { 910 struct chunk_info *p; 911 912 if (LIST_EMPTY(&d->chunk_info_list[bucket])) { 913 const size_t chunk_pages = 64; 914 size_t size, count, i; 915 char *q; 916 917 count = MALLOC_PAGESIZE / B2ALLOC(bucket); 918 919 size = howmany(count, MALLOC_BITS); 920 size = sizeof(struct chunk_info) + (size - 1) * sizeof(u_short); 921 if (mopts.chunk_canaries) 922 size += count * sizeof(u_short); 923 size = _ALIGN(size); 924 count = MALLOC_PAGESIZE / size; 925 926 /* Don't use cache here, we don't want user uaf touch this */ 927 if (d->chunk_pages_used == chunk_pages || 928 d->chunk_pages == NULL) { 929 q = MMAP(MALLOC_PAGESIZE * chunk_pages, d->mmap_flag); 930 if (q == MAP_FAILED) 931 return NULL; 932 d->chunk_pages = q; 933 d->chunk_pages_used = 0; 934 STATS_ADD(d->malloc_used, MALLOC_PAGESIZE * 935 chunk_pages); 936 } 937 q = (char *)d->chunk_pages + d->chunk_pages_used * 938 MALLOC_PAGESIZE; 939 d->chunk_pages_used++; 940 941 for (i = 0; i < count; i++, q += size) { 942 p = (struct chunk_info *)q; 943 LIST_INSERT_HEAD(&d->chunk_info_list[bucket], p, entries); 944 } 945 } 946 p = LIST_FIRST(&d->chunk_info_list[bucket]); 947 LIST_REMOVE(p, entries); 948 if (p->total == 0) 949 init_chunk_info(d, p, bucket); 950 return p; 951 } 952 953 /* 954 * Allocate a page of chunks 955 */ 956 static struct chunk_info * 957 omalloc_make_chunks(struct dir_info *d, u_int bucket, u_int listnum) 958 { 959 struct chunk_info *bp; 960 void *pp; 961 962 /* Allocate a new bucket */ 963 pp = map(d, MALLOC_PAGESIZE, 0); 964 if (pp == MAP_FAILED) 965 return NULL; 966 967 /* memory protect the page allocated in the malloc(0) case */ 968 if (bucket == 0 && mprotect(pp, MALLOC_PAGESIZE, PROT_NONE) == -1) 969 goto err; 970 971 bp = alloc_chunk_info(d, bucket); 972 if (bp == NULL) 973 goto err; 974 bp->page = pp; 975 976 if (insert(d, (void *)((uintptr_t)pp | (bucket + 1)), (uintptr_t)bp, 977 NULL)) 978 goto err; 979 LIST_INSERT_HEAD(&d->chunk_dir[bucket][listnum], bp, entries); 980 return bp; 981 982 err: 983 unmap(d, pp, MALLOC_PAGESIZE, 0); 984 return NULL; 985 } 986 987 static inline unsigned int 988 lb(u_int x) 989 { 990 /* I need an extension just for integer-length (: */ 991 return (sizeof(int) * CHAR_BIT - 1) - __builtin_clz(x); 992 } 993 994 /* https://pvk.ca/Blog/2015/06/27/linear-log-bucketing-fast-versatile-simple/ 995 via Tony Finch */ 996 static inline unsigned int 997 bin_of(unsigned int size) 998 { 999 const unsigned int linear = 6; 1000 const unsigned int subbin = 2; 1001 1002 unsigned int mask, range, rounded, sub_index, rounded_size; 1003 unsigned int n_bits, shift; 1004 1005 n_bits = lb(size | (1U << linear)); 1006 shift = n_bits - subbin; 1007 mask = (1ULL << shift) - 1; 1008 rounded = size + mask; /* XXX: overflow. */ 1009 sub_index = rounded >> shift; 1010 range = n_bits - linear; 1011 1012 rounded_size = rounded & ~mask; 1013 return rounded_size; 1014 } 1015 1016 static inline u_short 1017 find_bucket(u_short size) 1018 { 1019 /* malloc(0) is special */ 1020 if (size == 0) 1021 return 0; 1022 if (size < MALLOC_MINSIZE) 1023 size = MALLOC_MINSIZE; 1024 if (mopts.def_maxcache != 0) 1025 size = bin_of(size); 1026 return howmany(size, MALLOC_MINSIZE); 1027 } 1028 1029 static void 1030 fill_canary(char *ptr, size_t sz, size_t allocated) 1031 { 1032 size_t check_sz = allocated - sz; 1033 1034 if (check_sz > CHUNK_CHECK_LENGTH) 1035 check_sz = CHUNK_CHECK_LENGTH; 1036 memset(ptr + sz, mopts.chunk_canaries, check_sz); 1037 } 1038 1039 /* 1040 * Allocate a chunk 1041 */ 1042 static void * 1043 malloc_bytes(struct dir_info *d, size_t size, void *f) 1044 { 1045 u_int i, r, bucket, listnum; 1046 size_t k; 1047 u_short *lp; 1048 struct chunk_info *bp; 1049 void *p; 1050 1051 if (mopts.malloc_canary != (d->canary1 ^ (u_int32_t)(uintptr_t)d) || 1052 d->canary1 != ~d->canary2) 1053 wrterror(d, "internal struct corrupt"); 1054 1055 bucket = find_bucket(size); 1056 1057 r = ((u_int)getrbyte(d) << 8) | getrbyte(d); 1058 listnum = r % MALLOC_CHUNK_LISTS; 1059 1060 /* If it's empty, make a page more of that size chunks */ 1061 if ((bp = LIST_FIRST(&d->chunk_dir[bucket][listnum])) == NULL) { 1062 bp = omalloc_make_chunks(d, bucket, listnum); 1063 if (bp == NULL) 1064 return NULL; 1065 } 1066 1067 if (bp->canary != (u_short)d->canary1) 1068 wrterror(d, "chunk info corrupted"); 1069 1070 /* bias, as bp->total is not a power of 2 */ 1071 i = (r / MALLOC_CHUNK_LISTS) % bp->total; 1072 1073 /* potentially start somewhere in a short */ 1074 lp = &bp->bits[i / MALLOC_BITS]; 1075 if (*lp) { 1076 int j = i % MALLOC_BITS; /* j must be signed */ 1077 k = ffs(*lp >> j); 1078 if (k != 0) { 1079 k += j - 1; 1080 goto found; 1081 } 1082 } 1083 /* no bit halfway, go to next full short */ 1084 i /= MALLOC_BITS; 1085 for (;;) { 1086 if (++i >= howmany(bp->total, MALLOC_BITS)) 1087 i = 0; 1088 lp = &bp->bits[i]; 1089 if (*lp) { 1090 k = ffs(*lp) - 1; 1091 break; 1092 } 1093 } 1094 found: 1095 if (i == 0 && k == 0 && DO_STATS) { 1096 struct region_info *r = find(d, bp->page); 1097 STATS_SETF(r, f); 1098 } 1099 1100 *lp ^= 1 << k; 1101 1102 /* If there are no more free, remove from free-list */ 1103 if (--bp->free == 0) 1104 LIST_REMOVE(bp, entries); 1105 1106 /* Adjust to the real offset of that chunk */ 1107 k += (lp - bp->bits) * MALLOC_BITS; 1108 1109 if (mopts.chunk_canaries && size > 0) 1110 bp->bits[bp->offset + k] = size; 1111 1112 k *= B2ALLOC(bp->bucket); 1113 1114 p = (char *)bp->page + k; 1115 if (bp->bucket > 0) { 1116 if (d->malloc_junk == 2) 1117 memset(p, SOME_JUNK, B2SIZE(bp->bucket)); 1118 else if (mopts.chunk_canaries) 1119 fill_canary(p, size, B2SIZE(bp->bucket)); 1120 } 1121 return p; 1122 } 1123 1124 static void 1125 validate_canary(struct dir_info *d, u_char *ptr, size_t sz, size_t allocated) 1126 { 1127 size_t check_sz = allocated - sz; 1128 u_char *p, *q; 1129 1130 if (check_sz > CHUNK_CHECK_LENGTH) 1131 check_sz = CHUNK_CHECK_LENGTH; 1132 p = ptr + sz; 1133 q = p + check_sz; 1134 1135 while (p < q) { 1136 if (*p != (u_char)mopts.chunk_canaries && *p != SOME_JUNK) { 1137 wrterror(d, "chunk canary corrupted %p %#tx@%#zx%s", 1138 ptr, p - ptr, sz, 1139 *p == SOME_FREEJUNK ? " (double free?)" : ""); 1140 } 1141 p++; 1142 } 1143 } 1144 1145 static uint32_t 1146 find_chunknum(struct dir_info *d, struct chunk_info *info, void *ptr, int check) 1147 { 1148 uint32_t chunknum; 1149 1150 if (info->canary != (u_short)d->canary1) 1151 wrterror(d, "chunk info corrupted"); 1152 1153 /* Find the chunk number on the page */ 1154 chunknum = ((uintptr_t)ptr & MALLOC_PAGEMASK) / B2ALLOC(info->bucket); 1155 1156 if ((uintptr_t)ptr & (MALLOC_MINSIZE - 1)) 1157 wrterror(d, "modified chunk-pointer %p", ptr); 1158 if (info->bits[chunknum / MALLOC_BITS] & 1159 (1U << (chunknum % MALLOC_BITS))) 1160 wrterror(d, "chunk is already free %p", ptr); 1161 if (check && info->bucket > 0) { 1162 validate_canary(d, ptr, info->bits[info->offset + chunknum], 1163 B2SIZE(info->bucket)); 1164 } 1165 return chunknum; 1166 } 1167 1168 /* 1169 * Free a chunk, and possibly the page it's on, if the page becomes empty. 1170 */ 1171 static void 1172 free_bytes(struct dir_info *d, struct region_info *r, void *ptr) 1173 { 1174 struct chunk_head *mp; 1175 struct chunk_info *info; 1176 uint32_t chunknum; 1177 uint32_t listnum; 1178 1179 info = (struct chunk_info *)r->size; 1180 chunknum = find_chunknum(d, info, ptr, 0); 1181 1182 if (chunknum == 0) 1183 STATS_SETF(r, NULL); 1184 1185 info->bits[chunknum / MALLOC_BITS] |= 1U << (chunknum % MALLOC_BITS); 1186 info->free++; 1187 1188 if (info->free == 1) { 1189 /* Page became non-full */ 1190 listnum = getrbyte(d) % MALLOC_CHUNK_LISTS; 1191 mp = &d->chunk_dir[info->bucket][listnum]; 1192 LIST_INSERT_HEAD(mp, info, entries); 1193 return; 1194 } 1195 1196 if (info->free != info->total) 1197 return; 1198 1199 LIST_REMOVE(info, entries); 1200 1201 if (info->bucket == 0 && !mopts.malloc_freeunmap) 1202 mprotect(info->page, MALLOC_PAGESIZE, PROT_READ | PROT_WRITE); 1203 unmap(d, info->page, MALLOC_PAGESIZE, 0); 1204 1205 delete(d, r); 1206 mp = &d->chunk_info_list[info->bucket]; 1207 LIST_INSERT_HEAD(mp, info, entries); 1208 } 1209 1210 1211 1212 static void * 1213 omalloc(struct dir_info *pool, size_t sz, int zero_fill, void *f) 1214 { 1215 void *p; 1216 size_t psz; 1217 1218 if (sz > MALLOC_MAXCHUNK) { 1219 if (sz >= SIZE_MAX - mopts.malloc_guard - MALLOC_PAGESIZE) { 1220 errno = ENOMEM; 1221 return NULL; 1222 } 1223 sz += mopts.malloc_guard; 1224 psz = PAGEROUND(sz); 1225 p = map(pool, psz, zero_fill); 1226 if (p == MAP_FAILED) { 1227 errno = ENOMEM; 1228 return NULL; 1229 } 1230 if (insert(pool, p, sz, f)) { 1231 unmap(pool, p, psz, 0); 1232 errno = ENOMEM; 1233 return NULL; 1234 } 1235 if (mopts.malloc_guard) { 1236 if (mprotect((char *)p + psz - mopts.malloc_guard, 1237 mopts.malloc_guard, PROT_NONE)) 1238 wrterror(pool, "mprotect"); 1239 STATS_ADD(pool->malloc_guarded, mopts.malloc_guard); 1240 } 1241 1242 if (MALLOC_MOVE_COND(sz)) { 1243 /* fill whole allocation */ 1244 if (pool->malloc_junk == 2) 1245 memset(p, SOME_JUNK, psz - mopts.malloc_guard); 1246 /* shift towards the end */ 1247 p = MALLOC_MOVE(p, sz); 1248 /* fill zeros if needed and overwritten above */ 1249 if (zero_fill && pool->malloc_junk == 2) 1250 memset(p, 0, sz - mopts.malloc_guard); 1251 } else { 1252 if (pool->malloc_junk == 2) { 1253 if (zero_fill) 1254 memset((char *)p + sz - 1255 mopts.malloc_guard, SOME_JUNK, 1256 psz - sz); 1257 else 1258 memset(p, SOME_JUNK, 1259 psz - mopts.malloc_guard); 1260 } else if (mopts.chunk_canaries) 1261 fill_canary(p, sz - mopts.malloc_guard, 1262 psz - mopts.malloc_guard); 1263 } 1264 1265 } else { 1266 /* takes care of SOME_JUNK */ 1267 p = malloc_bytes(pool, sz, f); 1268 if (zero_fill && p != NULL && sz > 0) 1269 memset(p, 0, sz); 1270 } 1271 1272 return p; 1273 } 1274 1275 /* 1276 * Common function for handling recursion. Only 1277 * print the error message once, to avoid making the problem 1278 * potentially worse. 1279 */ 1280 static void 1281 malloc_recurse(struct dir_info *d) 1282 { 1283 static int noprint; 1284 1285 if (noprint == 0) { 1286 noprint = 1; 1287 wrterror(d, "recursive call"); 1288 } 1289 d->active--; 1290 _MALLOC_UNLOCK(d->mutex); 1291 errno = EDEADLK; 1292 } 1293 1294 void 1295 _malloc_init(int from_rthreads) 1296 { 1297 u_int i, j, nmutexes; 1298 struct dir_info *d; 1299 1300 _MALLOC_LOCK(1); 1301 if (!from_rthreads && mopts.malloc_pool[1]) { 1302 _MALLOC_UNLOCK(1); 1303 return; 1304 } 1305 if (!mopts.malloc_canary) { 1306 char *p; 1307 size_t sz, d_avail; 1308 1309 omalloc_init(); 1310 /* 1311 * Allocate dir_infos with a guard page on either side. Also 1312 * randomise offset inside the page at which the dir_infos 1313 * lay (subject to alignment by 1 << MALLOC_MINSHIFT) 1314 */ 1315 sz = mopts.malloc_mutexes * sizeof(*d) + 2 * MALLOC_PAGESIZE; 1316 if ((p = MMAPNONE(sz, 0)) == MAP_FAILED) 1317 wrterror(NULL, "malloc_init mmap1 failed"); 1318 if (mprotect(p + MALLOC_PAGESIZE, mopts.malloc_mutexes * sizeof(*d), 1319 PROT_READ | PROT_WRITE)) 1320 wrterror(NULL, "malloc_init mprotect1 failed"); 1321 if (mimmutable(p, sz)) 1322 wrterror(NULL, "malloc_init mimmutable1 failed"); 1323 d_avail = (((mopts.malloc_mutexes * sizeof(*d) + MALLOC_PAGEMASK) & 1324 ~MALLOC_PAGEMASK) - (mopts.malloc_mutexes * sizeof(*d))) >> 1325 MALLOC_MINSHIFT; 1326 d = (struct dir_info *)(p + MALLOC_PAGESIZE + 1327 (arc4random_uniform(d_avail) << MALLOC_MINSHIFT)); 1328 STATS_ADD(d[1].malloc_used, sz); 1329 for (i = 0; i < mopts.malloc_mutexes; i++) 1330 mopts.malloc_pool[i] = &d[i]; 1331 mopts.internal_funcs = 1; 1332 if (((uintptr_t)&malloc_readonly & MALLOC_PAGEMASK) == 0) { 1333 if (mprotect(&malloc_readonly, sizeof(malloc_readonly), 1334 PROT_READ)) 1335 wrterror(NULL, "malloc_init mprotect r/o failed"); 1336 if (mimmutable(&malloc_readonly, sizeof(malloc_readonly))) 1337 wrterror(NULL, "malloc_init mimmutable r/o failed"); 1338 } 1339 } 1340 1341 nmutexes = from_rthreads ? mopts.malloc_mutexes : 2; 1342 for (i = 0; i < nmutexes; i++) { 1343 d = mopts.malloc_pool[i]; 1344 d->malloc_mt = from_rthreads; 1345 if (d->canary1 == ~d->canary2) 1346 continue; 1347 if (i == 0) { 1348 omalloc_poolinit(d, MAP_CONCEAL); 1349 d->malloc_junk = 2; 1350 d->bigcache_size = 0; 1351 for (j = 0; j < MAX_SMALLCACHEABLE_SIZE; j++) 1352 d->smallcache[j].max = 0; 1353 } else { 1354 size_t sz = 0; 1355 1356 omalloc_poolinit(d, 0); 1357 d->malloc_junk = mopts.def_malloc_junk; 1358 d->bigcache_size = mopts.def_maxcache; 1359 for (j = 0; j < MAX_SMALLCACHEABLE_SIZE; j++) { 1360 d->smallcache[j].max = 1361 mopts.def_maxcache >> (j / 8); 1362 sz += d->smallcache[j].max * sizeof(void *); 1363 } 1364 sz += d->bigcache_size * sizeof(struct bigcache); 1365 if (sz > 0) { 1366 void *p = MMAP(sz, 0); 1367 if (p == MAP_FAILED) 1368 wrterror(NULL, 1369 "malloc_init mmap2 failed"); 1370 if (mimmutable(p, sz)) 1371 wrterror(NULL, "malloc_init mimmutable2 failed"); 1372 for (j = 0; j < MAX_SMALLCACHEABLE_SIZE; j++) { 1373 d->smallcache[j].pages = p; 1374 p = (char *)p + d->smallcache[j].max * 1375 sizeof(void *); 1376 } 1377 d->bigcache = p; 1378 } 1379 } 1380 d->mutex = i; 1381 } 1382 1383 _MALLOC_UNLOCK(1); 1384 } 1385 DEF_STRONG(_malloc_init); 1386 1387 #define PROLOGUE(p, fn) \ 1388 d = (p); \ 1389 if (d == NULL) { \ 1390 _malloc_init(0); \ 1391 d = (p); \ 1392 } \ 1393 _MALLOC_LOCK(d->mutex); \ 1394 d->func = fn; \ 1395 if (d->active++) { \ 1396 malloc_recurse(d); \ 1397 return NULL; \ 1398 } \ 1399 1400 #define EPILOGUE() \ 1401 d->active--; \ 1402 _MALLOC_UNLOCK(d->mutex); \ 1403 if (r == NULL && mopts.malloc_xmalloc) \ 1404 wrterror(d, "out of memory"); \ 1405 if (r != NULL) \ 1406 errno = saved_errno; \ 1407 1408 void * 1409 malloc(size_t size) 1410 { 1411 void *r; 1412 struct dir_info *d; 1413 int saved_errno = errno; 1414 1415 PROLOGUE(getpool(), "malloc") 1416 r = omalloc(d, size, 0, CALLER); 1417 EPILOGUE() 1418 return r; 1419 } 1420 /*DEF_STRONG(malloc);*/ 1421 1422 void * 1423 malloc_conceal(size_t size) 1424 { 1425 void *r; 1426 struct dir_info *d; 1427 int saved_errno = errno; 1428 1429 PROLOGUE(mopts.malloc_pool[0], "malloc_conceal") 1430 r = omalloc(d, size, 0, CALLER); 1431 EPILOGUE() 1432 return r; 1433 } 1434 DEF_WEAK(malloc_conceal); 1435 1436 static struct region_info * 1437 findpool(void *p, struct dir_info *argpool, struct dir_info **foundpool, 1438 char **saved_function) 1439 { 1440 struct dir_info *pool = argpool; 1441 struct region_info *r = find(pool, p); 1442 1443 STATS_INC(pool->pool_searches); 1444 if (r == NULL) { 1445 u_int i, nmutexes; 1446 1447 nmutexes = mopts.malloc_pool[1]->malloc_mt ? mopts.malloc_mutexes : 2; 1448 STATS_INC(pool->other_pool); 1449 for (i = 1; i < nmutexes; i++) { 1450 u_int j = (argpool->mutex + i) & (nmutexes - 1); 1451 1452 pool->active--; 1453 _MALLOC_UNLOCK(pool->mutex); 1454 pool = mopts.malloc_pool[j]; 1455 _MALLOC_LOCK(pool->mutex); 1456 pool->active++; 1457 r = find(pool, p); 1458 if (r != NULL) { 1459 *saved_function = pool->func; 1460 pool->func = argpool->func; 1461 break; 1462 } 1463 } 1464 if (r == NULL) 1465 wrterror(argpool, "bogus pointer (double free?) %p", p); 1466 } 1467 *foundpool = pool; 1468 return r; 1469 } 1470 1471 static void 1472 ofree(struct dir_info **argpool, void *p, int clear, int check, size_t argsz) 1473 { 1474 struct region_info *r; 1475 struct dir_info *pool; 1476 char *saved_function; 1477 size_t sz; 1478 1479 r = findpool(p, *argpool, &pool, &saved_function); 1480 1481 REALSIZE(sz, r); 1482 if (pool->mmap_flag) { 1483 clear = 1; 1484 if (!check) { 1485 argsz = sz; 1486 if (sz > MALLOC_MAXCHUNK) 1487 argsz -= mopts.malloc_guard; 1488 } 1489 } 1490 if (check) { 1491 if (sz <= MALLOC_MAXCHUNK) { 1492 if (mopts.chunk_canaries && sz > 0) { 1493 struct chunk_info *info = 1494 (struct chunk_info *)r->size; 1495 uint32_t chunknum = 1496 find_chunknum(pool, info, p, 0); 1497 1498 if (info->bits[info->offset + chunknum] < argsz) 1499 wrterror(pool, "recorded size %hu" 1500 " < %zu", 1501 info->bits[info->offset + chunknum], 1502 argsz); 1503 } else { 1504 if (sz < argsz) 1505 wrterror(pool, "chunk size %zu < %zu", 1506 sz, argsz); 1507 } 1508 } else if (sz - mopts.malloc_guard < argsz) { 1509 wrterror(pool, "recorded size %zu < %zu", 1510 sz - mopts.malloc_guard, argsz); 1511 } 1512 } 1513 if (sz > MALLOC_MAXCHUNK) { 1514 if (!MALLOC_MOVE_COND(sz)) { 1515 if (r->p != p) 1516 wrterror(pool, "bogus pointer %p", p); 1517 if (mopts.chunk_canaries) 1518 validate_canary(pool, p, 1519 sz - mopts.malloc_guard, 1520 PAGEROUND(sz - mopts.malloc_guard)); 1521 } else { 1522 /* shifted towards the end */ 1523 if (p != MALLOC_MOVE(r->p, sz)) 1524 wrterror(pool, "bogus moved pointer %p", p); 1525 p = r->p; 1526 } 1527 if (mopts.malloc_guard) { 1528 if (sz < mopts.malloc_guard) 1529 wrterror(pool, "guard size"); 1530 if (!mopts.malloc_freeunmap) { 1531 if (mprotect((char *)p + PAGEROUND(sz) - 1532 mopts.malloc_guard, mopts.malloc_guard, 1533 PROT_READ | PROT_WRITE)) 1534 wrterror(pool, "mprotect"); 1535 } 1536 STATS_SUB(pool->malloc_guarded, mopts.malloc_guard); 1537 } 1538 unmap(pool, p, PAGEROUND(sz), clear ? argsz : 0); 1539 delete(pool, r); 1540 } else { 1541 void *tmp; 1542 u_int i; 1543 1544 /* Validate and optionally canary check */ 1545 struct chunk_info *info = (struct chunk_info *)r->size; 1546 if (B2SIZE(info->bucket) != sz) 1547 wrterror(pool, "internal struct corrupt"); 1548 find_chunknum(pool, info, p, mopts.chunk_canaries); 1549 1550 if (mopts.malloc_freecheck) { 1551 for (i = 0; i <= MALLOC_DELAYED_CHUNK_MASK; i++) { 1552 tmp = pool->delayed_chunks[i]; 1553 if (tmp == p) 1554 wrterror(pool, 1555 "double free %p", p); 1556 if (tmp != NULL) { 1557 size_t tmpsz; 1558 1559 r = find(pool, tmp); 1560 if (r == NULL) 1561 wrterror(pool, 1562 "bogus pointer (" 1563 "double free?) %p", tmp); 1564 REALSIZE(tmpsz, r); 1565 validate_junk(pool, tmp, tmpsz); 1566 } 1567 } 1568 } 1569 1570 if (clear && argsz > 0) 1571 explicit_bzero(p, argsz); 1572 junk_free(pool->malloc_junk, p, sz); 1573 1574 i = getrbyte(pool) & MALLOC_DELAYED_CHUNK_MASK; 1575 tmp = p; 1576 p = pool->delayed_chunks[i]; 1577 if (tmp == p) 1578 wrterror(pool, "double free %p", p); 1579 pool->delayed_chunks[i] = tmp; 1580 if (p != NULL) { 1581 r = find(pool, p); 1582 if (r == NULL) 1583 wrterror(pool, 1584 "bogus pointer (double free?) %p", p); 1585 if (!mopts.malloc_freecheck) { 1586 REALSIZE(sz, r); 1587 validate_junk(pool, p, sz); 1588 } 1589 free_bytes(pool, r, p); 1590 } 1591 } 1592 1593 if (*argpool != pool) { 1594 pool->func = saved_function; 1595 *argpool = pool; 1596 } 1597 } 1598 1599 void 1600 free(void *ptr) 1601 { 1602 struct dir_info *d; 1603 int saved_errno = errno; 1604 1605 /* This is legal. */ 1606 if (ptr == NULL) 1607 return; 1608 1609 d = getpool(); 1610 if (d == NULL) 1611 wrterror(d, "free() called before allocation"); 1612 _MALLOC_LOCK(d->mutex); 1613 d->func = "free"; 1614 if (d->active++) { 1615 malloc_recurse(d); 1616 return; 1617 } 1618 ofree(&d, ptr, 0, 0, 0); 1619 d->active--; 1620 _MALLOC_UNLOCK(d->mutex); 1621 errno = saved_errno; 1622 } 1623 /*DEF_STRONG(free);*/ 1624 1625 static void 1626 freezero_p(void *ptr, size_t sz) 1627 { 1628 explicit_bzero(ptr, sz); 1629 free(ptr); 1630 } 1631 1632 void 1633 freezero(void *ptr, size_t sz) 1634 { 1635 struct dir_info *d; 1636 int saved_errno = errno; 1637 1638 /* This is legal. */ 1639 if (ptr == NULL) 1640 return; 1641 1642 if (!mopts.internal_funcs) { 1643 freezero_p(ptr, sz); 1644 return; 1645 } 1646 1647 d = getpool(); 1648 if (d == NULL) 1649 wrterror(d, "freezero() called before allocation"); 1650 _MALLOC_LOCK(d->mutex); 1651 d->func = "freezero"; 1652 if (d->active++) { 1653 malloc_recurse(d); 1654 return; 1655 } 1656 ofree(&d, ptr, 1, 1, sz); 1657 d->active--; 1658 _MALLOC_UNLOCK(d->mutex); 1659 errno = saved_errno; 1660 } 1661 DEF_WEAK(freezero); 1662 1663 static void * 1664 orealloc(struct dir_info **argpool, void *p, size_t newsz, void *f) 1665 { 1666 struct region_info *r; 1667 struct dir_info *pool; 1668 char *saved_function; 1669 struct chunk_info *info; 1670 size_t oldsz, goldsz, gnewsz; 1671 void *q, *ret; 1672 uint32_t chunknum; 1673 int forced; 1674 1675 if (p == NULL) 1676 return omalloc(*argpool, newsz, 0, f); 1677 1678 if (newsz >= SIZE_MAX - mopts.malloc_guard - MALLOC_PAGESIZE) { 1679 errno = ENOMEM; 1680 return NULL; 1681 } 1682 1683 r = findpool(p, *argpool, &pool, &saved_function); 1684 1685 REALSIZE(oldsz, r); 1686 if (oldsz <= MALLOC_MAXCHUNK) { 1687 if (DO_STATS || mopts.chunk_canaries) { 1688 info = (struct chunk_info *)r->size; 1689 chunknum = find_chunknum(pool, info, p, 0); 1690 } 1691 } 1692 1693 goldsz = oldsz; 1694 if (oldsz > MALLOC_MAXCHUNK) { 1695 if (oldsz < mopts.malloc_guard) 1696 wrterror(pool, "guard size"); 1697 oldsz -= mopts.malloc_guard; 1698 } 1699 1700 gnewsz = newsz; 1701 if (gnewsz > MALLOC_MAXCHUNK) 1702 gnewsz += mopts.malloc_guard; 1703 1704 forced = mopts.malloc_realloc || pool->mmap_flag; 1705 if (newsz > MALLOC_MAXCHUNK && oldsz > MALLOC_MAXCHUNK && !forced) { 1706 /* First case: from n pages sized allocation to m pages sized 1707 allocation, m > n */ 1708 size_t roldsz = PAGEROUND(goldsz); 1709 size_t rnewsz = PAGEROUND(gnewsz); 1710 1711 if (rnewsz < roldsz && rnewsz > roldsz / 2 && 1712 roldsz - rnewsz < mopts.def_maxcache * MALLOC_PAGESIZE && 1713 !mopts.malloc_guard) { 1714 1715 ret = p; 1716 goto done; 1717 } 1718 1719 if (rnewsz > roldsz) { 1720 /* try to extend existing region */ 1721 if (!mopts.malloc_guard) { 1722 void *hint = (char *)r->p + roldsz; 1723 size_t needed = rnewsz - roldsz; 1724 1725 STATS_INC(pool->cheap_realloc_tries); 1726 q = MMAPA(hint, needed, MAP_FIXED | __MAP_NOREPLACE | pool->mmap_flag); 1727 if (q == hint) { 1728 STATS_ADD(pool->malloc_used, needed); 1729 if (pool->malloc_junk == 2) 1730 memset(q, SOME_JUNK, needed); 1731 r->size = gnewsz; 1732 if (r->p != p) { 1733 /* old pointer is moved */ 1734 memmove(r->p, p, oldsz); 1735 p = r->p; 1736 } 1737 if (mopts.chunk_canaries) 1738 fill_canary(p, newsz, 1739 PAGEROUND(newsz)); 1740 STATS_SETF(r, f); 1741 STATS_INC(pool->cheap_reallocs); 1742 ret = p; 1743 goto done; 1744 } 1745 } 1746 } else if (rnewsz < roldsz) { 1747 /* shrink number of pages */ 1748 if (mopts.malloc_guard) { 1749 if (mprotect((char *)r->p + rnewsz - 1750 mopts.malloc_guard, mopts.malloc_guard, 1751 PROT_NONE)) 1752 wrterror(pool, "mprotect"); 1753 } 1754 if (munmap((char *)r->p + rnewsz, roldsz - rnewsz)) 1755 wrterror(pool, "munmap %p", (char *)r->p + 1756 rnewsz); 1757 STATS_SUB(pool->malloc_used, roldsz - rnewsz); 1758 r->size = gnewsz; 1759 if (MALLOC_MOVE_COND(gnewsz)) { 1760 void *pp = MALLOC_MOVE(r->p, gnewsz); 1761 memmove(pp, p, newsz); 1762 p = pp; 1763 } else if (mopts.chunk_canaries) 1764 fill_canary(p, newsz, PAGEROUND(newsz)); 1765 STATS_SETF(r, f); 1766 ret = p; 1767 goto done; 1768 } else { 1769 /* number of pages remains the same */ 1770 void *pp = r->p; 1771 1772 r->size = gnewsz; 1773 if (MALLOC_MOVE_COND(gnewsz)) 1774 pp = MALLOC_MOVE(r->p, gnewsz); 1775 if (p != pp) { 1776 memmove(pp, p, oldsz < newsz ? oldsz : newsz); 1777 p = pp; 1778 } 1779 if (p == r->p) { 1780 if (newsz > oldsz && pool->malloc_junk == 2) 1781 memset((char *)p + newsz, SOME_JUNK, 1782 rnewsz - mopts.malloc_guard - 1783 newsz); 1784 if (mopts.chunk_canaries) 1785 fill_canary(p, newsz, PAGEROUND(newsz)); 1786 } 1787 STATS_SETF(r, f); 1788 ret = p; 1789 goto done; 1790 } 1791 } 1792 if (oldsz <= MALLOC_MAXCHUNK && oldsz > 0 && 1793 newsz <= MALLOC_MAXCHUNK && newsz > 0 && 1794 !forced && find_bucket(newsz) == find_bucket(oldsz)) { 1795 /* do not reallocate if new size fits good in existing chunk */ 1796 if (pool->malloc_junk == 2) 1797 memset((char *)p + newsz, SOME_JUNK, oldsz - newsz); 1798 if (mopts.chunk_canaries) { 1799 info->bits[info->offset + chunknum] = newsz; 1800 fill_canary(p, newsz, B2SIZE(info->bucket)); 1801 } 1802 if (DO_STATS && chunknum == 0) 1803 STATS_SETF(r, f); 1804 ret = p; 1805 } else if (newsz != oldsz || forced) { 1806 /* create new allocation */ 1807 q = omalloc(pool, newsz, 0, f); 1808 if (q == NULL) { 1809 ret = NULL; 1810 goto done; 1811 } 1812 if (newsz != 0 && oldsz != 0) 1813 memcpy(q, p, oldsz < newsz ? oldsz : newsz); 1814 ofree(&pool, p, 0, 0, 0); 1815 ret = q; 1816 } else { 1817 /* oldsz == newsz */ 1818 if (newsz != 0) 1819 wrterror(pool, "realloc internal inconsistency"); 1820 if (DO_STATS && chunknum == 0) 1821 STATS_SETF(r, f); 1822 ret = p; 1823 } 1824 done: 1825 if (*argpool != pool) { 1826 pool->func = saved_function; 1827 *argpool = pool; 1828 } 1829 return ret; 1830 } 1831 1832 void * 1833 realloc(void *ptr, size_t size) 1834 { 1835 struct dir_info *d; 1836 void *r; 1837 int saved_errno = errno; 1838 1839 PROLOGUE(getpool(), "realloc") 1840 r = orealloc(&d, ptr, size, CALLER); 1841 EPILOGUE() 1842 return r; 1843 } 1844 /*DEF_STRONG(realloc);*/ 1845 1846 /* 1847 * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX 1848 * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW 1849 */ 1850 #define MUL_NO_OVERFLOW (1UL << (sizeof(size_t) * 4)) 1851 1852 void * 1853 calloc(size_t nmemb, size_t size) 1854 { 1855 struct dir_info *d; 1856 void *r; 1857 int saved_errno = errno; 1858 1859 PROLOGUE(getpool(), "calloc") 1860 if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) && 1861 nmemb > 0 && SIZE_MAX / nmemb < size) { 1862 d->active--; 1863 _MALLOC_UNLOCK(d->mutex); 1864 if (mopts.malloc_xmalloc) 1865 wrterror(d, "out of memory"); 1866 errno = ENOMEM; 1867 return NULL; 1868 } 1869 1870 size *= nmemb; 1871 r = omalloc(d, size, 1, CALLER); 1872 EPILOGUE() 1873 return r; 1874 } 1875 /*DEF_STRONG(calloc);*/ 1876 1877 void * 1878 calloc_conceal(size_t nmemb, size_t size) 1879 { 1880 struct dir_info *d; 1881 void *r; 1882 int saved_errno = errno; 1883 1884 PROLOGUE(mopts.malloc_pool[0], "calloc_conceal") 1885 if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) && 1886 nmemb > 0 && SIZE_MAX / nmemb < size) { 1887 d->active--; 1888 _MALLOC_UNLOCK(d->mutex); 1889 if (mopts.malloc_xmalloc) 1890 wrterror(d, "out of memory"); 1891 errno = ENOMEM; 1892 return NULL; 1893 } 1894 1895 size *= nmemb; 1896 r = omalloc(d, size, 1, CALLER); 1897 EPILOGUE() 1898 return r; 1899 } 1900 DEF_WEAK(calloc_conceal); 1901 1902 static void * 1903 orecallocarray(struct dir_info **argpool, void *p, size_t oldsize, 1904 size_t newsize, void *f) 1905 { 1906 struct region_info *r; 1907 struct dir_info *pool; 1908 char *saved_function; 1909 void *newptr; 1910 size_t sz; 1911 1912 if (p == NULL) 1913 return omalloc(*argpool, newsize, 1, f); 1914 1915 if (oldsize == newsize) 1916 return p; 1917 1918 r = findpool(p, *argpool, &pool, &saved_function); 1919 1920 REALSIZE(sz, r); 1921 if (sz <= MALLOC_MAXCHUNK) { 1922 if (mopts.chunk_canaries && sz > 0) { 1923 struct chunk_info *info = (struct chunk_info *)r->size; 1924 uint32_t chunknum = find_chunknum(pool, info, p, 0); 1925 1926 if (info->bits[info->offset + chunknum] != oldsize) 1927 wrterror(pool, "recorded old size %hu != %zu", 1928 info->bits[info->offset + chunknum], 1929 oldsize); 1930 } 1931 } else if (oldsize < (sz - mopts.malloc_guard) / 2) 1932 wrterror(pool, "recorded old size %zu != %zu", 1933 sz - mopts.malloc_guard, oldsize); 1934 1935 newptr = omalloc(pool, newsize, 0, f); 1936 if (newptr == NULL) 1937 goto done; 1938 1939 if (newsize > oldsize) { 1940 memcpy(newptr, p, oldsize); 1941 memset((char *)newptr + oldsize, 0, newsize - oldsize); 1942 } else 1943 memcpy(newptr, p, newsize); 1944 1945 ofree(&pool, p, 1, 0, oldsize); 1946 1947 done: 1948 if (*argpool != pool) { 1949 pool->func = saved_function; 1950 *argpool = pool; 1951 } 1952 1953 return newptr; 1954 } 1955 1956 static void * 1957 recallocarray_p(void *ptr, size_t oldnmemb, size_t newnmemb, size_t size) 1958 { 1959 size_t oldsize, newsize; 1960 void *newptr; 1961 1962 if (ptr == NULL) 1963 return calloc(newnmemb, size); 1964 1965 if ((newnmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) && 1966 newnmemb > 0 && SIZE_MAX / newnmemb < size) { 1967 errno = ENOMEM; 1968 return NULL; 1969 } 1970 newsize = newnmemb * size; 1971 1972 if ((oldnmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) && 1973 oldnmemb > 0 && SIZE_MAX / oldnmemb < size) { 1974 errno = EINVAL; 1975 return NULL; 1976 } 1977 oldsize = oldnmemb * size; 1978 1979 /* 1980 * Don't bother too much if we're shrinking just a bit, 1981 * we do not shrink for series of small steps, oh well. 1982 */ 1983 if (newsize <= oldsize) { 1984 size_t d = oldsize - newsize; 1985 1986 if (d < oldsize / 2 && d < MALLOC_PAGESIZE) { 1987 memset((char *)ptr + newsize, 0, d); 1988 return ptr; 1989 } 1990 } 1991 1992 newptr = malloc(newsize); 1993 if (newptr == NULL) 1994 return NULL; 1995 1996 if (newsize > oldsize) { 1997 memcpy(newptr, ptr, oldsize); 1998 memset((char *)newptr + oldsize, 0, newsize - oldsize); 1999 } else 2000 memcpy(newptr, ptr, newsize); 2001 2002 explicit_bzero(ptr, oldsize); 2003 free(ptr); 2004 2005 return newptr; 2006 } 2007 2008 void * 2009 recallocarray(void *ptr, size_t oldnmemb, size_t newnmemb, size_t size) 2010 { 2011 struct dir_info *d; 2012 size_t oldsize = 0, newsize; 2013 void *r; 2014 int saved_errno = errno; 2015 2016 if (!mopts.internal_funcs) 2017 return recallocarray_p(ptr, oldnmemb, newnmemb, size); 2018 2019 PROLOGUE(getpool(), "recallocarray") 2020 2021 if ((newnmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) && 2022 newnmemb > 0 && SIZE_MAX / newnmemb < size) { 2023 d->active--; 2024 _MALLOC_UNLOCK(d->mutex); 2025 if (mopts.malloc_xmalloc) 2026 wrterror(d, "out of memory"); 2027 errno = ENOMEM; 2028 return NULL; 2029 } 2030 newsize = newnmemb * size; 2031 2032 if (ptr != NULL) { 2033 if ((oldnmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) && 2034 oldnmemb > 0 && SIZE_MAX / oldnmemb < size) { 2035 d->active--; 2036 _MALLOC_UNLOCK(d->mutex); 2037 errno = EINVAL; 2038 return NULL; 2039 } 2040 oldsize = oldnmemb * size; 2041 } 2042 2043 r = orecallocarray(&d, ptr, oldsize, newsize, CALLER); 2044 EPILOGUE() 2045 return r; 2046 } 2047 DEF_WEAK(recallocarray); 2048 2049 static void * 2050 mapalign(struct dir_info *d, size_t alignment, size_t sz, int zero_fill) 2051 { 2052 char *p, *q; 2053 2054 if (alignment < MALLOC_PAGESIZE || ((alignment - 1) & alignment) != 0) 2055 wrterror(d, "mapalign bad alignment"); 2056 if (sz != PAGEROUND(sz)) 2057 wrterror(d, "mapalign round"); 2058 2059 /* Allocate sz + alignment bytes of memory, which must include a 2060 * subrange of size bytes that is properly aligned. Unmap the 2061 * other bytes, and then return that subrange. 2062 */ 2063 2064 /* We need sz + alignment to fit into a size_t. */ 2065 if (alignment > SIZE_MAX - sz) 2066 return MAP_FAILED; 2067 2068 p = map(d, sz + alignment, zero_fill); 2069 if (p == MAP_FAILED) 2070 return MAP_FAILED; 2071 q = (char *)(((uintptr_t)p + alignment - 1) & ~(alignment - 1)); 2072 if (q != p) { 2073 if (munmap(p, q - p)) 2074 wrterror(d, "munmap %p", p); 2075 } 2076 if (munmap(q + sz, alignment - (q - p))) 2077 wrterror(d, "munmap %p", q + sz); 2078 STATS_SUB(d->malloc_used, alignment); 2079 2080 return q; 2081 } 2082 2083 static void * 2084 omemalign(struct dir_info *pool, size_t alignment, size_t sz, int zero_fill, 2085 void *f) 2086 { 2087 size_t psz; 2088 void *p; 2089 2090 /* If between half a page and a page, avoid MALLOC_MOVE. */ 2091 if (sz > MALLOC_MAXCHUNK && sz < MALLOC_PAGESIZE) 2092 sz = MALLOC_PAGESIZE; 2093 if (alignment <= MALLOC_PAGESIZE) { 2094 size_t pof2; 2095 /* 2096 * max(size, alignment) rounded up to power of 2 is enough 2097 * to assure the requested alignment. Large regions are 2098 * always page aligned. 2099 */ 2100 if (sz < alignment) 2101 sz = alignment; 2102 if (sz < MALLOC_PAGESIZE) { 2103 pof2 = MALLOC_MINSIZE; 2104 while (pof2 < sz) 2105 pof2 <<= 1; 2106 } else 2107 pof2 = sz; 2108 return omalloc(pool, pof2, zero_fill, f); 2109 } 2110 2111 if (sz >= SIZE_MAX - mopts.malloc_guard - MALLOC_PAGESIZE) { 2112 errno = ENOMEM; 2113 return NULL; 2114 } 2115 2116 if (sz < MALLOC_PAGESIZE) 2117 sz = MALLOC_PAGESIZE; 2118 sz += mopts.malloc_guard; 2119 psz = PAGEROUND(sz); 2120 2121 p = mapalign(pool, alignment, psz, zero_fill); 2122 if (p == MAP_FAILED) { 2123 errno = ENOMEM; 2124 return NULL; 2125 } 2126 2127 if (insert(pool, p, sz, f)) { 2128 unmap(pool, p, psz, 0); 2129 errno = ENOMEM; 2130 return NULL; 2131 } 2132 2133 if (mopts.malloc_guard) { 2134 if (mprotect((char *)p + psz - mopts.malloc_guard, 2135 mopts.malloc_guard, PROT_NONE)) 2136 wrterror(pool, "mprotect"); 2137 STATS_ADD(pool->malloc_guarded, mopts.malloc_guard); 2138 } 2139 2140 if (pool->malloc_junk == 2) { 2141 if (zero_fill) 2142 memset((char *)p + sz - mopts.malloc_guard, 2143 SOME_JUNK, psz - sz); 2144 else 2145 memset(p, SOME_JUNK, psz - mopts.malloc_guard); 2146 } else if (mopts.chunk_canaries) 2147 fill_canary(p, sz - mopts.malloc_guard, 2148 psz - mopts.malloc_guard); 2149 2150 return p; 2151 } 2152 2153 int 2154 posix_memalign(void **memptr, size_t alignment, size_t size) 2155 { 2156 struct dir_info *d; 2157 int res, saved_errno = errno; 2158 void *r; 2159 2160 /* Make sure that alignment is a large enough power of 2. */ 2161 if (((alignment - 1) & alignment) != 0 || alignment < sizeof(void *)) 2162 return EINVAL; 2163 2164 d = getpool(); 2165 if (d == NULL) { 2166 _malloc_init(0); 2167 d = getpool(); 2168 } 2169 _MALLOC_LOCK(d->mutex); 2170 d->func = "posix_memalign"; 2171 if (d->active++) { 2172 malloc_recurse(d); 2173 goto err; 2174 } 2175 r = omemalign(d, alignment, size, 0, CALLER); 2176 d->active--; 2177 _MALLOC_UNLOCK(d->mutex); 2178 if (r == NULL) { 2179 if (mopts.malloc_xmalloc) 2180 wrterror(d, "out of memory"); 2181 goto err; 2182 } 2183 errno = saved_errno; 2184 *memptr = r; 2185 return 0; 2186 2187 err: 2188 res = errno; 2189 errno = saved_errno; 2190 return res; 2191 } 2192 /*DEF_STRONG(posix_memalign);*/ 2193 2194 void * 2195 aligned_alloc(size_t alignment, size_t size) 2196 { 2197 struct dir_info *d; 2198 int saved_errno = errno; 2199 void *r; 2200 2201 /* Make sure that alignment is a positive power of 2. */ 2202 if (((alignment - 1) & alignment) != 0 || alignment == 0) { 2203 errno = EINVAL; 2204 return NULL; 2205 }; 2206 /* Per spec, size should be a multiple of alignment */ 2207 if ((size & (alignment - 1)) != 0) { 2208 errno = EINVAL; 2209 return NULL; 2210 } 2211 2212 PROLOGUE(getpool(), "aligned_alloc") 2213 r = omemalign(d, alignment, size, 0, CALLER); 2214 EPILOGUE() 2215 return r; 2216 } 2217 /*DEF_STRONG(aligned_alloc);*/ 2218 2219 #ifdef MALLOC_STATS 2220 2221 static void 2222 ulog(const char *format, ...) 2223 { 2224 va_list ap; 2225 static char* buf; 2226 static size_t filled; 2227 int len; 2228 2229 if (buf == NULL) 2230 buf = MMAP(KTR_USER_MAXLEN, 0); 2231 if (buf == MAP_FAILED) 2232 return; 2233 2234 va_start(ap, format); 2235 len = vsnprintf(buf + filled, KTR_USER_MAXLEN - filled, format, ap); 2236 va_end(ap); 2237 if (len < 0) 2238 return; 2239 if (len > KTR_USER_MAXLEN - filled) 2240 len = KTR_USER_MAXLEN - filled; 2241 filled += len; 2242 if (filled > 0) { 2243 if (filled == KTR_USER_MAXLEN || buf[filled - 1] == '\n') { 2244 utrace("malloc", buf, filled); 2245 filled = 0; 2246 } 2247 } 2248 } 2249 2250 struct malloc_leak { 2251 void *f; 2252 size_t total_size; 2253 int count; 2254 }; 2255 2256 struct leaknode { 2257 RBT_ENTRY(leaknode) entry; 2258 struct malloc_leak d; 2259 }; 2260 2261 static inline int 2262 leakcmp(const struct leaknode *e1, const struct leaknode *e2) 2263 { 2264 return e1->d.f < e2->d.f ? -1 : e1->d.f > e2->d.f; 2265 } 2266 2267 RBT_HEAD(leaktree, leaknode); 2268 RBT_PROTOTYPE(leaktree, leaknode, entry, leakcmp); 2269 RBT_GENERATE(leaktree, leaknode, entry, leakcmp); 2270 2271 static void 2272 putleakinfo(struct leaktree *leaks, void *f, size_t sz, int cnt) 2273 { 2274 struct leaknode key, *p; 2275 static struct leaknode *page; 2276 static unsigned int used; 2277 2278 if (cnt == 0 || page == MAP_FAILED) 2279 return; 2280 2281 key.d.f = f; 2282 p = RBT_FIND(leaktree, leaks, &key); 2283 if (p == NULL) { 2284 if (page == NULL || 2285 used >= MALLOC_PAGESIZE / sizeof(struct leaknode)) { 2286 page = MMAP(MALLOC_PAGESIZE, 0); 2287 if (page == MAP_FAILED) 2288 return; 2289 used = 0; 2290 } 2291 p = &page[used++]; 2292 p->d.f = f; 2293 p->d.total_size = sz * cnt; 2294 p->d.count = cnt; 2295 RBT_INSERT(leaktree, leaks, p); 2296 } else { 2297 p->d.total_size += sz * cnt; 2298 p->d.count += cnt; 2299 } 2300 } 2301 2302 static void 2303 dump_leaks(struct leaktree *leaks) 2304 { 2305 struct leaknode *p; 2306 2307 ulog("Leak report:\n"); 2308 ulog(" f sum # avg\n"); 2309 2310 RBT_FOREACH(p, leaktree, leaks) { 2311 Dl_info info; 2312 const char *caller = p->d.f; 2313 const char *object = "."; 2314 2315 if (caller != NULL) { 2316 if (dladdr(p->d.f, &info) != 0) { 2317 caller -= (uintptr_t)info.dli_fbase; 2318 object = info.dli_fname; 2319 } 2320 } 2321 ulog("%18p %7zu %6u %6zu addr2line -e %s %p\n", 2322 p->d.f, p->d.total_size, p->d.count, 2323 p->d.total_size / p->d.count, 2324 object, caller); 2325 } 2326 } 2327 2328 static void 2329 dump_chunk(struct leaktree* leaks, struct chunk_info *p, void *f, 2330 int fromfreelist) 2331 { 2332 while (p != NULL) { 2333 if (mopts.malloc_verbose) 2334 ulog("chunk %18p %18p %4zu %d/%d\n", 2335 p->page, ((p->bits[0] & 1) ? NULL : f), 2336 B2SIZE(p->bucket), p->free, p->total); 2337 if (!fromfreelist) { 2338 size_t sz = B2SIZE(p->bucket); 2339 if (p->bits[0] & 1) 2340 putleakinfo(leaks, NULL, sz, p->total - 2341 p->free); 2342 else { 2343 putleakinfo(leaks, f, sz, 1); 2344 putleakinfo(leaks, NULL, sz, 2345 p->total - p->free - 1); 2346 } 2347 break; 2348 } 2349 p = LIST_NEXT(p, entries); 2350 if (mopts.malloc_verbose && p != NULL) 2351 ulog(" ->"); 2352 } 2353 } 2354 2355 static void 2356 dump_free_chunk_info(struct dir_info *d, struct leaktree *leaks) 2357 { 2358 int i, j, count; 2359 struct chunk_info *p; 2360 2361 ulog("Free chunk structs:\n"); 2362 ulog("Bkt) #CI page" 2363 " f size free/n\n"); 2364 for (i = 0; i <= BUCKETS; i++) { 2365 count = 0; 2366 LIST_FOREACH(p, &d->chunk_info_list[i], entries) 2367 count++; 2368 for (j = 0; j < MALLOC_CHUNK_LISTS; j++) { 2369 p = LIST_FIRST(&d->chunk_dir[i][j]); 2370 if (p == NULL && count == 0) 2371 continue; 2372 if (j == 0) 2373 ulog("%3d) %3d ", i, count); 2374 else 2375 ulog(" "); 2376 if (p != NULL) 2377 dump_chunk(leaks, p, NULL, 1); 2378 else 2379 ulog(".\n"); 2380 } 2381 } 2382 2383 } 2384 2385 static void 2386 dump_free_page_info(struct dir_info *d) 2387 { 2388 struct smallcache *cache; 2389 size_t i, total = 0; 2390 2391 ulog("Cached in small cache:\n"); 2392 for (i = 0; i < MAX_SMALLCACHEABLE_SIZE; i++) { 2393 cache = &d->smallcache[i]; 2394 if (cache->length != 0) 2395 ulog("%zu(%u): %u = %zu\n", i + 1, cache->max, 2396 cache->length, cache->length * (i + 1)); 2397 total += cache->length * (i + 1); 2398 } 2399 2400 ulog("Cached in big cache: %zu/%zu\n", d->bigcache_used, 2401 d->bigcache_size); 2402 for (i = 0; i < d->bigcache_size; i++) { 2403 if (d->bigcache[i].psize != 0) 2404 ulog("%zu: %zu\n", i, d->bigcache[i].psize); 2405 total += d->bigcache[i].psize; 2406 } 2407 ulog("Free pages cached: %zu\n", total); 2408 } 2409 2410 static void 2411 malloc_dump1(int poolno, struct dir_info *d, struct leaktree *leaks) 2412 { 2413 size_t i, realsize; 2414 2415 if (mopts.malloc_verbose) { 2416 ulog("Malloc dir of %s pool %d at %p\n", __progname, poolno, d); 2417 ulog("MT=%d J=%d Fl=%x\n", d->malloc_mt, d->malloc_junk, 2418 d->mmap_flag); 2419 ulog("Region slots free %zu/%zu\n", 2420 d->regions_free, d->regions_total); 2421 ulog("Finds %zu/%zu\n", d->finds, d->find_collisions); 2422 ulog("Inserts %zu/%zu\n", d->inserts, d->insert_collisions); 2423 ulog("Deletes %zu/%zu\n", d->deletes, d->delete_moves); 2424 ulog("Cheap reallocs %zu/%zu\n", 2425 d->cheap_reallocs, d->cheap_realloc_tries); 2426 ulog("Other pool searches %zu/%zu\n", 2427 d->other_pool, d->pool_searches); 2428 ulog("In use %zu\n", d->malloc_used); 2429 ulog("Guarded %zu\n", d->malloc_guarded); 2430 dump_free_chunk_info(d, leaks); 2431 dump_free_page_info(d); 2432 ulog("Hash table:\n"); 2433 ulog("slot) hash d type page " 2434 "f size [free/n]\n"); 2435 } 2436 for (i = 0; i < d->regions_total; i++) { 2437 if (d->r[i].p != NULL) { 2438 size_t h = hash(d->r[i].p) & 2439 (d->regions_total - 1); 2440 if (mopts.malloc_verbose) 2441 ulog("%4zx) #%4zx %zd ", 2442 i, h, h - i); 2443 REALSIZE(realsize, &d->r[i]); 2444 if (realsize > MALLOC_MAXCHUNK) { 2445 putleakinfo(leaks, d->r[i].f, realsize, 1); 2446 if (mopts.malloc_verbose) 2447 ulog("pages %18p %18p %zu\n", d->r[i].p, 2448 d->r[i].f, realsize); 2449 } else 2450 dump_chunk(leaks, 2451 (struct chunk_info *)d->r[i].size, 2452 d->r[i].f, 0); 2453 } 2454 } 2455 if (mopts.malloc_verbose) 2456 ulog("\n"); 2457 } 2458 2459 static void 2460 malloc_dump0(int poolno, struct dir_info *pool, struct leaktree *leaks) 2461 { 2462 int i; 2463 void *p; 2464 struct region_info *r; 2465 2466 if (pool == NULL || pool->r == NULL) 2467 return; 2468 for (i = 0; i < MALLOC_DELAYED_CHUNK_MASK + 1; i++) { 2469 p = pool->delayed_chunks[i]; 2470 if (p == NULL) 2471 continue; 2472 r = find(pool, p); 2473 if (r == NULL) 2474 wrterror(pool, "bogus pointer in malloc_dump %p", p); 2475 free_bytes(pool, r, p); 2476 pool->delayed_chunks[i] = NULL; 2477 } 2478 malloc_dump1(poolno, pool, leaks); 2479 } 2480 2481 void 2482 malloc_dump(void) 2483 { 2484 int i; 2485 int saved_errno = errno; 2486 2487 /* XXX leak when run multiple times */ 2488 struct leaktree leaks = RBT_INITIALIZER(&leaks); 2489 2490 for (i = 0; i < mopts.malloc_mutexes; i++) 2491 malloc_dump0(i, mopts.malloc_pool[i], &leaks); 2492 2493 dump_leaks(&leaks); 2494 ulog("\n"); 2495 errno = saved_errno; 2496 } 2497 DEF_WEAK(malloc_dump); 2498 2499 static void 2500 malloc_exit(void) 2501 { 2502 int save_errno = errno; 2503 2504 ulog("******** Start dump %s *******\n", __progname); 2505 ulog("M=%u I=%d F=%d U=%d J=%d R=%d X=%d C=%d cache=%u " 2506 "G=%zu\n", 2507 mopts.malloc_mutexes, 2508 mopts.internal_funcs, mopts.malloc_freecheck, 2509 mopts.malloc_freeunmap, mopts.def_malloc_junk, 2510 mopts.malloc_realloc, mopts.malloc_xmalloc, 2511 mopts.chunk_canaries, mopts.def_maxcache, 2512 mopts.malloc_guard); 2513 2514 malloc_dump(); 2515 ulog("******** End dump %s *******\n", __progname); 2516 errno = save_errno; 2517 } 2518 2519 #endif /* MALLOC_STATS */ 2520