xref: /openbsd-src/lib/libc/stdlib/malloc.c (revision c0dd97bfcad3dab6c31ec12b9de1274fd2d2f993)
1 /*	$OpenBSD: malloc.c,v 1.235 2017/10/19 16:34:33 jsing Exp $	*/
2 /*
3  * Copyright (c) 2008, 2010, 2011, 2016 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 /* #define MALLOC_STATS */
27 
28 #include <sys/types.h>
29 #include <sys/param.h>	/* PAGE_SHIFT ALIGN */
30 #include <sys/queue.h>
31 #include <sys/mman.h>
32 #include <sys/uio.h>
33 #include <errno.h>
34 #include <stdarg.h>
35 #include <stdint.h>
36 #include <stdlib.h>
37 #include <string.h>
38 #include <stdio.h>
39 #include <unistd.h>
40 
41 #ifdef MALLOC_STATS
42 #include <sys/tree.h>
43 #include <fcntl.h>
44 #endif
45 
46 #include "thread_private.h"
47 #include <tib.h>
48 
49 #if defined(__mips64__)
50 #define MALLOC_PAGESHIFT	(14U)
51 #else
52 #define MALLOC_PAGESHIFT	(PAGE_SHIFT)
53 #endif
54 
55 #define MALLOC_MINSHIFT		4
56 #define MALLOC_MAXSHIFT		(MALLOC_PAGESHIFT - 1)
57 #define MALLOC_PAGESIZE		(1UL << MALLOC_PAGESHIFT)
58 #define MALLOC_MINSIZE		(1UL << MALLOC_MINSHIFT)
59 #define MALLOC_PAGEMASK		(MALLOC_PAGESIZE - 1)
60 #define MASK_POINTER(p)		((void *)(((uintptr_t)(p)) & ~MALLOC_PAGEMASK))
61 
62 #define MALLOC_MAXCHUNK		(1 << MALLOC_MAXSHIFT)
63 #define MALLOC_MAXCACHE		256
64 #define MALLOC_DELAYED_CHUNK_MASK	15
65 #define MALLOC_INITIAL_REGIONS	512
66 #define MALLOC_DEFAULT_CACHE	64
67 #define MALLOC_CHUNK_LISTS	4
68 #define CHUNK_CHECK_LENGTH	32
69 
70 /*
71  * We move allocations between half a page and a whole page towards the end,
72  * subject to alignment constraints. This is the extra headroom we allow.
73  * Set to zero to be the most strict.
74  */
75 #define MALLOC_LEEWAY		0
76 #define MALLOC_MOVE_COND(sz)	((sz) - mopts.malloc_guard < 		\
77 				    MALLOC_PAGESIZE - MALLOC_LEEWAY)
78 #define MALLOC_MOVE(p, sz)  	(((char *)(p)) +			\
79 				    ((MALLOC_PAGESIZE - MALLOC_LEEWAY -	\
80 			    	    ((sz) - mopts.malloc_guard)) & 	\
81 				    ~(MALLOC_MINSIZE - 1)))
82 
83 #define PAGEROUND(x)  (((x) + (MALLOC_PAGEMASK)) & ~MALLOC_PAGEMASK)
84 
85 /*
86  * What to use for Junk.  This is the byte value we use to fill with
87  * when the 'J' option is enabled. Use SOME_JUNK right after alloc,
88  * and SOME_FREEJUNK right before free.
89  */
90 #define SOME_JUNK		0xdb	/* deadbeef */
91 #define SOME_FREEJUNK		0xdf	/* dead, free */
92 
93 #define MMAP(sz)	mmap(NULL, (sz), PROT_READ | PROT_WRITE, \
94     MAP_ANON | MAP_PRIVATE, -1, 0)
95 
96 #define MMAPA(a,sz)	mmap((a), (sz), PROT_READ | PROT_WRITE, \
97     MAP_ANON | MAP_PRIVATE, -1, 0)
98 
99 #define MQUERY(a, sz)	mquery((a), (sz), PROT_READ | PROT_WRITE, \
100     MAP_ANON | MAP_PRIVATE | MAP_FIXED, -1, 0)
101 
102 struct region_info {
103 	void *p;		/* page; low bits used to mark chunks */
104 	uintptr_t size;		/* size for pages, or chunk_info pointer */
105 #ifdef MALLOC_STATS
106 	void *f;		/* where allocated from */
107 #endif
108 };
109 
110 LIST_HEAD(chunk_head, chunk_info);
111 
112 struct dir_info {
113 	u_int32_t canary1;
114 	int active;			/* status of malloc */
115 	struct region_info *r;		/* region slots */
116 	size_t regions_total;		/* number of region slots */
117 	size_t regions_free;		/* number of free slots */
118 					/* lists of free chunk info structs */
119 	struct chunk_head chunk_info_list[MALLOC_MAXSHIFT + 1];
120 					/* lists of chunks with free slots */
121 	struct chunk_head chunk_dir[MALLOC_MAXSHIFT + 1][MALLOC_CHUNK_LISTS];
122 	size_t free_regions_size;	/* free pages cached */
123 					/* free pages cache */
124 	struct region_info free_regions[MALLOC_MAXCACHE];
125 					/* delayed free chunk slots */
126 	void *delayed_chunks[MALLOC_DELAYED_CHUNK_MASK + 1];
127 	size_t rbytesused;		/* random bytes used */
128 	char *func;			/* current function */
129 	int mutex;
130 	u_char rbytes[32];		/* random bytes */
131 	u_short chunk_start;
132 #ifdef MALLOC_STATS
133 	size_t inserts;
134 	size_t insert_collisions;
135 	size_t finds;
136 	size_t find_collisions;
137 	size_t deletes;
138 	size_t delete_moves;
139 	size_t cheap_realloc_tries;
140 	size_t cheap_reallocs;
141 	size_t malloc_used;		/* bytes allocated */
142 	size_t malloc_guarded;		/* bytes used for guards */
143 #define STATS_ADD(x,y)	((x) += (y))
144 #define STATS_SUB(x,y)	((x) -= (y))
145 #define STATS_INC(x)	((x)++)
146 #define STATS_ZERO(x)	((x) = 0)
147 #define STATS_SETF(x,y)	((x)->f = (y))
148 #else
149 #define STATS_ADD(x,y)	/* nothing */
150 #define STATS_SUB(x,y)	/* nothing */
151 #define STATS_INC(x)	/* nothing */
152 #define STATS_ZERO(x)	/* nothing */
153 #define STATS_SETF(x,y)	/* nothing */
154 #endif /* MALLOC_STATS */
155 	u_int32_t canary2;
156 };
157 #define DIR_INFO_RSZ	((sizeof(struct dir_info) + MALLOC_PAGEMASK) & \
158 			~MALLOC_PAGEMASK)
159 
160 /*
161  * This structure describes a page worth of chunks.
162  *
163  * How many bits per u_short in the bitmap
164  */
165 #define MALLOC_BITS		(NBBY * sizeof(u_short))
166 struct chunk_info {
167 	LIST_ENTRY(chunk_info) entries;
168 	void *page;			/* pointer to the page */
169 	u_int32_t canary;
170 	u_short size;			/* size of this page's chunks */
171 	u_short shift;			/* how far to shift for this size */
172 	u_short free;			/* how many free chunks */
173 	u_short total;			/* how many chunks */
174 	u_short offset;			/* requested size table offset */
175 					/* which chunks are free */
176 	u_short bits[1];
177 };
178 
179 struct malloc_readonly {
180 	struct dir_info *malloc_pool[_MALLOC_MUTEXES];	/* Main bookkeeping information */
181 	int	malloc_mt;		/* multi-threaded mode? */
182 	int	malloc_freecheck;	/* Extensive double free check */
183 	int	malloc_freeunmap;	/* mprotect free pages PROT_NONE? */
184 	int	malloc_junk;		/* junk fill? */
185 	int	malloc_realloc;		/* always realloc? */
186 	int	malloc_xmalloc;		/* xmalloc behaviour? */
187 	int	chunk_canaries;		/* use canaries after chunks? */
188 	int	internal_funcs;		/* use better recallocarray/freezero? */
189 	u_int	malloc_cache;		/* free pages we cache */
190 	size_t	malloc_guard;		/* use guard pages after allocations? */
191 #ifdef MALLOC_STATS
192 	int	malloc_stats;		/* dump statistics at end */
193 #endif
194 	u_int32_t malloc_canary;	/* Matched against ones in malloc_pool */
195 };
196 
197 /* This object is mapped PROT_READ after initialisation to prevent tampering */
198 static union {
199 	struct malloc_readonly mopts;
200 	u_char _pad[MALLOC_PAGESIZE];
201 } malloc_readonly __attribute__((aligned(MALLOC_PAGESIZE)));
202 #define mopts	malloc_readonly.mopts
203 
204 char		*malloc_options;	/* compile-time options */
205 
206 static u_char getrbyte(struct dir_info *d);
207 static __dead void wrterror(struct dir_info *d, char *msg, ...)
208     __attribute__((__format__ (printf, 2, 3)));
209 static void fill_canary(char *ptr, size_t sz, size_t allocated);
210 
211 #ifdef MALLOC_STATS
212 void malloc_dump(int, int, struct dir_info *);
213 PROTO_NORMAL(malloc_dump);
214 void malloc_gdump(int);
215 PROTO_NORMAL(malloc_gdump);
216 static void malloc_exit(void);
217 #define CALLER	__builtin_return_address(0)
218 #else
219 #define CALLER	NULL
220 #endif
221 
222 /* low bits of r->p determine size: 0 means >= page size and r->size holding
223  * real size, otherwise low bits are a shift count, or 1 for malloc(0)
224  */
225 #define REALSIZE(sz, r)						\
226 	(sz) = (uintptr_t)(r)->p & MALLOC_PAGEMASK,		\
227 	(sz) = ((sz) == 0 ? (r)->size : ((sz) == 1 ? 0 : (1 << ((sz)-1))))
228 
229 static inline void
230 _MALLOC_LEAVE(struct dir_info *d)
231 {
232 	if (mopts.malloc_mt) {
233 		d->active--;
234 		_MALLOC_UNLOCK(d->mutex);
235 	}
236 }
237 
238 static inline void
239 _MALLOC_ENTER(struct dir_info *d)
240 {
241 	if (mopts.malloc_mt) {
242 		_MALLOC_LOCK(d->mutex);
243 		d->active++;
244 	}
245 }
246 
247 static inline size_t
248 hash(void *p)
249 {
250 	size_t sum;
251 	uintptr_t u;
252 
253 	u = (uintptr_t)p >> MALLOC_PAGESHIFT;
254 	sum = u;
255 	sum = (sum << 7) - sum + (u >> 16);
256 #ifdef __LP64__
257 	sum = (sum << 7) - sum + (u >> 32);
258 	sum = (sum << 7) - sum + (u >> 48);
259 #endif
260 	return sum;
261 }
262 
263 static inline
264 struct dir_info *getpool(void)
265 {
266 	if (!mopts.malloc_mt)
267 		return mopts.malloc_pool[0];
268 	else
269 		return mopts.malloc_pool[TIB_GET()->tib_tid &
270 		    (_MALLOC_MUTEXES - 1)];
271 }
272 
273 static __dead void
274 wrterror(struct dir_info *d, char *msg, ...)
275 {
276 	int		saved_errno = errno;
277 	va_list		ap;
278 
279 	dprintf(STDERR_FILENO, "%s(%d) in %s(): ", __progname,
280 	    getpid(), (d != NULL && d->func) ? d->func : "unknown");
281 	va_start(ap, msg);
282 	vdprintf(STDERR_FILENO, msg, ap);
283 	va_end(ap);
284 	dprintf(STDERR_FILENO, "\n");
285 
286 #ifdef MALLOC_STATS
287 	if (mopts.malloc_stats)
288 		malloc_gdump(STDERR_FILENO);
289 #endif /* MALLOC_STATS */
290 
291 	errno = saved_errno;
292 
293 	abort();
294 }
295 
296 static void
297 rbytes_init(struct dir_info *d)
298 {
299 	arc4random_buf(d->rbytes, sizeof(d->rbytes));
300 	/* add 1 to account for using d->rbytes[0] */
301 	d->rbytesused = 1 + d->rbytes[0] % (sizeof(d->rbytes) / 2);
302 }
303 
304 static inline u_char
305 getrbyte(struct dir_info *d)
306 {
307 	u_char x;
308 
309 	if (d->rbytesused >= sizeof(d->rbytes))
310 		rbytes_init(d);
311 	x = d->rbytes[d->rbytesused++];
312 	return x;
313 }
314 
315 /*
316  * Cache maintenance. We keep at most malloc_cache pages cached.
317  * If the cache is becoming full, unmap pages in the cache for real,
318  * and then add the region to the cache
319  * Opposed to the regular region data structure, the sizes in the
320  * cache are in MALLOC_PAGESIZE units.
321  */
322 static void
323 unmap(struct dir_info *d, void *p, size_t sz, int clear)
324 {
325 	size_t psz = sz >> MALLOC_PAGESHIFT;
326 	size_t rsz, tounmap;
327 	struct region_info *r;
328 	u_int i, offset;
329 
330 	if (sz != PAGEROUND(sz))
331 		wrterror(d, "munmap round");
332 
333 	rsz = mopts.malloc_cache - d->free_regions_size;
334 
335 	/*
336 	 * normally the cache holds recently freed regions, but if the region
337 	 * to unmap is larger than the cache size or we're clearing and the
338 	 * cache is full, just munmap
339 	 */
340 	if (psz > mopts.malloc_cache || (clear && rsz == 0)) {
341 		i = munmap(p, sz);
342 		if (i)
343 			wrterror(d, "munmap %p", p);
344 		STATS_SUB(d->malloc_used, sz);
345 		return;
346 	}
347 	tounmap = 0;
348 	if (psz > rsz)
349 		tounmap = psz - rsz;
350 	offset = getrbyte(d);
351 	for (i = 0; tounmap > 0 && i < mopts.malloc_cache; i++) {
352 		r = &d->free_regions[(i + offset) & (mopts.malloc_cache - 1)];
353 		if (r->p != NULL) {
354 			rsz = r->size << MALLOC_PAGESHIFT;
355 			if (munmap(r->p, rsz))
356 				wrterror(d, "munmap %p", r->p);
357 			r->p = NULL;
358 			if (tounmap > r->size)
359 				tounmap -= r->size;
360 			else
361 				tounmap = 0;
362 			d->free_regions_size -= r->size;
363 			r->size = 0;
364 			STATS_SUB(d->malloc_used, rsz);
365 		}
366 	}
367 	if (tounmap > 0)
368 		wrterror(d, "malloc cache underflow");
369 	for (i = 0; i < mopts.malloc_cache; i++) {
370 		r = &d->free_regions[(i + offset) & (mopts.malloc_cache - 1)];
371 		if (r->p == NULL) {
372 			if (clear)
373 				memset(p, 0, sz - mopts.malloc_guard);
374 			if (mopts.malloc_junk && !mopts.malloc_freeunmap) {
375 				size_t amt = mopts.malloc_junk == 1 ?
376 				    MALLOC_MAXCHUNK : sz;
377 				memset(p, SOME_FREEJUNK, amt);
378 			}
379 			if (mopts.malloc_freeunmap)
380 				mprotect(p, sz, PROT_NONE);
381 			r->p = p;
382 			r->size = psz;
383 			d->free_regions_size += psz;
384 			break;
385 		}
386 	}
387 	if (i == mopts.malloc_cache)
388 		wrterror(d, "malloc free slot lost");
389 	if (d->free_regions_size > mopts.malloc_cache)
390 		wrterror(d, "malloc cache overflow");
391 }
392 
393 static void
394 zapcacheregion(struct dir_info *d, void *p, size_t len)
395 {
396 	u_int i;
397 	struct region_info *r;
398 	size_t rsz;
399 
400 	for (i = 0; i < mopts.malloc_cache; i++) {
401 		r = &d->free_regions[i];
402 		if (r->p >= p && r->p <= (void *)((char *)p + len)) {
403 			rsz = r->size << MALLOC_PAGESHIFT;
404 			if (munmap(r->p, rsz))
405 				wrterror(d, "munmap %p", r->p);
406 			r->p = NULL;
407 			d->free_regions_size -= r->size;
408 			r->size = 0;
409 			STATS_SUB(d->malloc_used, rsz);
410 		}
411 	}
412 }
413 
414 static void *
415 map(struct dir_info *d, void *hint, size_t sz, int zero_fill)
416 {
417 	size_t psz = sz >> MALLOC_PAGESHIFT;
418 	struct region_info *r, *big = NULL;
419 	u_int i, offset;
420 	void *p;
421 
422 	if (mopts.malloc_canary != (d->canary1 ^ (u_int32_t)(uintptr_t)d) ||
423 	    d->canary1 != ~d->canary2)
424 		wrterror(d, "internal struct corrupt");
425 	if (sz != PAGEROUND(sz))
426 		wrterror(d, "map round");
427 
428 	if (!hint && psz > d->free_regions_size) {
429 		_MALLOC_LEAVE(d);
430 		p = MMAP(sz);
431 		_MALLOC_ENTER(d);
432 		if (p != MAP_FAILED)
433 			STATS_ADD(d->malloc_used, sz);
434 		/* zero fill not needed */
435 		return p;
436 	}
437 	offset = getrbyte(d);
438 	for (i = 0; i < mopts.malloc_cache; i++) {
439 		r = &d->free_regions[(i + offset) & (mopts.malloc_cache - 1)];
440 		if (r->p != NULL) {
441 			if (hint && r->p != hint)
442 				continue;
443 			if (r->size == psz) {
444 				p = r->p;
445 				r->p = NULL;
446 				r->size = 0;
447 				d->free_regions_size -= psz;
448 				if (mopts.malloc_freeunmap)
449 					mprotect(p, sz, PROT_READ | PROT_WRITE);
450 				if (zero_fill)
451 					memset(p, 0, sz);
452 				else if (mopts.malloc_junk == 2 &&
453 				    mopts.malloc_freeunmap)
454 					memset(p, SOME_FREEJUNK, sz);
455 				return p;
456 			} else if (r->size > psz)
457 				big = r;
458 		}
459 	}
460 	if (big != NULL) {
461 		r = big;
462 		p = r->p;
463 		r->p = (char *)r->p + (psz << MALLOC_PAGESHIFT);
464 		if (mopts.malloc_freeunmap)
465 			mprotect(p, sz, PROT_READ | PROT_WRITE);
466 		r->size -= psz;
467 		d->free_regions_size -= psz;
468 		if (zero_fill)
469 			memset(p, 0, sz);
470 		else if (mopts.malloc_junk == 2 && mopts.malloc_freeunmap)
471 			memset(p, SOME_FREEJUNK, sz);
472 		return p;
473 	}
474 	if (hint)
475 		return MAP_FAILED;
476 	if (d->free_regions_size > mopts.malloc_cache)
477 		wrterror(d, "malloc cache");
478 	_MALLOC_LEAVE(d);
479 	p = MMAP(sz);
480 	_MALLOC_ENTER(d);
481 	if (p != MAP_FAILED)
482 		STATS_ADD(d->malloc_used, sz);
483 	/* zero fill not needed */
484 	return p;
485 }
486 
487 static void
488 omalloc_parseopt(char opt)
489 {
490 	switch (opt) {
491 	case '>':
492 		mopts.malloc_cache <<= 1;
493 		if (mopts.malloc_cache > MALLOC_MAXCACHE)
494 			mopts.malloc_cache = MALLOC_MAXCACHE;
495 		break;
496 	case '<':
497 		mopts.malloc_cache >>= 1;
498 		break;
499 	case 'c':
500 		mopts.chunk_canaries = 0;
501 		break;
502 	case 'C':
503 		mopts.chunk_canaries = 1;
504 		break;
505 #ifdef MALLOC_STATS
506 	case 'd':
507 		mopts.malloc_stats = 0;
508 		break;
509 	case 'D':
510 		mopts.malloc_stats = 1;
511 		break;
512 #endif /* MALLOC_STATS */
513 	case 'f':
514 		mopts.malloc_freecheck = 0;
515 		mopts.malloc_freeunmap = 0;
516 		break;
517 	case 'F':
518 		mopts.malloc_freecheck = 1;
519 		mopts.malloc_freeunmap = 1;
520 		break;
521 	case 'g':
522 		mopts.malloc_guard = 0;
523 		break;
524 	case 'G':
525 		mopts.malloc_guard = MALLOC_PAGESIZE;
526 		break;
527 	case 'j':
528 		if (mopts.malloc_junk > 0)
529 			mopts.malloc_junk--;
530 		break;
531 	case 'J':
532 		if (mopts.malloc_junk < 2)
533 			mopts.malloc_junk++;
534 		break;
535 	case 'r':
536 		mopts.malloc_realloc = 0;
537 		break;
538 	case 'R':
539 		mopts.malloc_realloc = 1;
540 		break;
541 	case 'u':
542 		mopts.malloc_freeunmap = 0;
543 		break;
544 	case 'U':
545 		mopts.malloc_freeunmap = 1;
546 		break;
547 	case 'x':
548 		mopts.malloc_xmalloc = 0;
549 		break;
550 	case 'X':
551 		mopts.malloc_xmalloc = 1;
552 		break;
553 	default: {
554 		dprintf(STDERR_FILENO, "malloc() warning: "
555                     "unknown char in MALLOC_OPTIONS\n");
556 		break;
557 	}
558 	}
559 }
560 
561 static void
562 omalloc_init(void)
563 {
564 	char *p, *q, b[64];
565 	int i, j;
566 
567 	/*
568 	 * Default options
569 	 */
570 	mopts.malloc_junk = 1;
571 	mopts.malloc_cache = MALLOC_DEFAULT_CACHE;
572 
573 	for (i = 0; i < 3; i++) {
574 		switch (i) {
575 		case 0:
576 			j = readlink("/etc/malloc.conf", b, sizeof b - 1);
577 			if (j <= 0)
578 				continue;
579 			b[j] = '\0';
580 			p = b;
581 			break;
582 		case 1:
583 			if (issetugid() == 0)
584 				p = getenv("MALLOC_OPTIONS");
585 			else
586 				continue;
587 			break;
588 		case 2:
589 			p = malloc_options;
590 			break;
591 		default:
592 			p = NULL;
593 		}
594 
595 		for (; p != NULL && *p != '\0'; p++) {
596 			switch (*p) {
597 			case 'S':
598 				for (q = "CFGJ"; *q != '\0'; q++)
599 					omalloc_parseopt(*q);
600 				mopts.malloc_cache = 0;
601 				break;
602 			case 's':
603 				for (q = "cgj"; *q != '\0'; q++)
604 					omalloc_parseopt(*q);
605 				mopts.malloc_cache = MALLOC_DEFAULT_CACHE;
606 				break;
607 			default:
608 				omalloc_parseopt(*p);
609 				break;
610 			}
611 		}
612 	}
613 
614 #ifdef MALLOC_STATS
615 	if (mopts.malloc_stats && (atexit(malloc_exit) == -1)) {
616 		dprintf(STDERR_FILENO, "malloc() warning: atexit(2) failed."
617 		    " Will not be able to dump stats on exit\n");
618 	}
619 #endif /* MALLOC_STATS */
620 
621 	while ((mopts.malloc_canary = arc4random()) == 0)
622 		;
623 }
624 
625 /*
626  * Initialize a dir_info, which should have been cleared by caller
627  */
628 static void
629 omalloc_poolinit(struct dir_info **dp)
630 {
631 	void *p;
632 	size_t d_avail, regioninfo_size;
633 	struct dir_info *d;
634 	int i, j;
635 
636 	/*
637 	 * Allocate dir_info with a guard page on either side. Also
638 	 * randomise offset inside the page at which the dir_info
639 	 * lies (subject to alignment by 1 << MALLOC_MINSHIFT)
640 	 */
641 	if ((p = MMAP(DIR_INFO_RSZ + (MALLOC_PAGESIZE * 2))) == MAP_FAILED)
642 		wrterror(NULL, "malloc init mmap failed");
643 	mprotect(p, MALLOC_PAGESIZE, PROT_NONE);
644 	mprotect((char *)p + MALLOC_PAGESIZE + DIR_INFO_RSZ,
645 	    MALLOC_PAGESIZE, PROT_NONE);
646 	d_avail = (DIR_INFO_RSZ - sizeof(*d)) >> MALLOC_MINSHIFT;
647 	d = (struct dir_info *)((char *)p + MALLOC_PAGESIZE +
648 	    (arc4random_uniform(d_avail) << MALLOC_MINSHIFT));
649 
650 	rbytes_init(d);
651 	d->regions_free = d->regions_total = MALLOC_INITIAL_REGIONS;
652 	regioninfo_size = d->regions_total * sizeof(struct region_info);
653 	d->r = MMAP(regioninfo_size);
654 	if (d->r == MAP_FAILED) {
655 		d->regions_total = 0;
656 		wrterror(NULL, "malloc init mmap failed");
657 	}
658 	for (i = 0; i <= MALLOC_MAXSHIFT; i++) {
659 		LIST_INIT(&d->chunk_info_list[i]);
660 		for (j = 0; j < MALLOC_CHUNK_LISTS; j++)
661 			LIST_INIT(&d->chunk_dir[i][j]);
662 	}
663 	STATS_ADD(d->malloc_used, regioninfo_size);
664 	d->canary1 = mopts.malloc_canary ^ (u_int32_t)(uintptr_t)d;
665 	d->canary2 = ~d->canary1;
666 
667 	*dp = d;
668 }
669 
670 static int
671 omalloc_grow(struct dir_info *d)
672 {
673 	size_t newtotal;
674 	size_t newsize;
675 	size_t mask;
676 	size_t i;
677 	struct region_info *p;
678 
679 	if (d->regions_total > SIZE_MAX / sizeof(struct region_info) / 2 )
680 		return 1;
681 
682 	newtotal = d->regions_total * 2;
683 	newsize = newtotal * sizeof(struct region_info);
684 	mask = newtotal - 1;
685 
686 	p = MMAP(newsize);
687 	if (p == MAP_FAILED)
688 		return 1;
689 
690 	STATS_ADD(d->malloc_used, newsize);
691 	STATS_ZERO(d->inserts);
692 	STATS_ZERO(d->insert_collisions);
693 	for (i = 0; i < d->regions_total; i++) {
694 		void *q = d->r[i].p;
695 		if (q != NULL) {
696 			size_t index = hash(q) & mask;
697 			STATS_INC(d->inserts);
698 			while (p[index].p != NULL) {
699 				index = (index - 1) & mask;
700 				STATS_INC(d->insert_collisions);
701 			}
702 			p[index] = d->r[i];
703 		}
704 	}
705 	/* avoid pages containing meta info to end up in cache */
706 	if (munmap(d->r, d->regions_total * sizeof(struct region_info)))
707 		wrterror(d, "munmap %p", (void *)d->r);
708 	else
709 		STATS_SUB(d->malloc_used,
710 		    d->regions_total * sizeof(struct region_info));
711 	d->regions_free = d->regions_free + d->regions_total;
712 	d->regions_total = newtotal;
713 	d->r = p;
714 	return 0;
715 }
716 
717 static struct chunk_info *
718 alloc_chunk_info(struct dir_info *d, int bits)
719 {
720 	struct chunk_info *p;
721 	size_t size, count;
722 
723 	if (bits == 0)
724 		count = MALLOC_PAGESIZE / MALLOC_MINSIZE;
725 	else
726 		count = MALLOC_PAGESIZE >> bits;
727 
728 	size = howmany(count, MALLOC_BITS);
729 	size = sizeof(struct chunk_info) + (size - 1) * sizeof(u_short);
730 	if (mopts.chunk_canaries)
731 		size += count * sizeof(u_short);
732 	size = ALIGN(size);
733 
734 	if (LIST_EMPTY(&d->chunk_info_list[bits])) {
735 		char *q;
736 		size_t i;
737 
738 		q = MMAP(MALLOC_PAGESIZE);
739 		if (q == MAP_FAILED)
740 			return NULL;
741 		STATS_ADD(d->malloc_used, MALLOC_PAGESIZE);
742 		count = MALLOC_PAGESIZE / size;
743 		for (i = 0; i < count; i++, q += size)
744 			LIST_INSERT_HEAD(&d->chunk_info_list[bits],
745 			    (struct chunk_info *)q, entries);
746 	}
747 	p = LIST_FIRST(&d->chunk_info_list[bits]);
748 	LIST_REMOVE(p, entries);
749 	memset(p, 0, size);
750 	p->canary = d->canary1;
751 	return p;
752 }
753 
754 
755 /*
756  * The hashtable uses the assumption that p is never NULL. This holds since
757  * non-MAP_FIXED mappings with hint 0 start at BRKSIZ.
758  */
759 static int
760 insert(struct dir_info *d, void *p, size_t sz, void *f)
761 {
762 	size_t index;
763 	size_t mask;
764 	void *q;
765 
766 	if (d->regions_free * 4 < d->regions_total) {
767 		if (omalloc_grow(d))
768 			return 1;
769 	}
770 	mask = d->regions_total - 1;
771 	index = hash(p) & mask;
772 	q = d->r[index].p;
773 	STATS_INC(d->inserts);
774 	while (q != NULL) {
775 		index = (index - 1) & mask;
776 		q = d->r[index].p;
777 		STATS_INC(d->insert_collisions);
778 	}
779 	d->r[index].p = p;
780 	d->r[index].size = sz;
781 #ifdef MALLOC_STATS
782 	d->r[index].f = f;
783 #endif
784 	d->regions_free--;
785 	return 0;
786 }
787 
788 static struct region_info *
789 find(struct dir_info *d, void *p)
790 {
791 	size_t index;
792 	size_t mask = d->regions_total - 1;
793 	void *q, *r;
794 
795 	if (mopts.malloc_canary != (d->canary1 ^ (u_int32_t)(uintptr_t)d) ||
796 	    d->canary1 != ~d->canary2)
797 		wrterror(d, "internal struct corrupt");
798 	p = MASK_POINTER(p);
799 	index = hash(p) & mask;
800 	r = d->r[index].p;
801 	q = MASK_POINTER(r);
802 	STATS_INC(d->finds);
803 	while (q != p && r != NULL) {
804 		index = (index - 1) & mask;
805 		r = d->r[index].p;
806 		q = MASK_POINTER(r);
807 		STATS_INC(d->find_collisions);
808 	}
809 	return (q == p && r != NULL) ? &d->r[index] : NULL;
810 }
811 
812 static void
813 delete(struct dir_info *d, struct region_info *ri)
814 {
815 	/* algorithm R, Knuth Vol III section 6.4 */
816 	size_t mask = d->regions_total - 1;
817 	size_t i, j, r;
818 
819 	if (d->regions_total & (d->regions_total - 1))
820 		wrterror(d, "regions_total not 2^x");
821 	d->regions_free++;
822 	STATS_INC(d->deletes);
823 
824 	i = ri - d->r;
825 	for (;;) {
826 		d->r[i].p = NULL;
827 		d->r[i].size = 0;
828 		j = i;
829 		for (;;) {
830 			i = (i - 1) & mask;
831 			if (d->r[i].p == NULL)
832 				return;
833 			r = hash(d->r[i].p) & mask;
834 			if ((i <= r && r < j) || (r < j && j < i) ||
835 			    (j < i && i <= r))
836 				continue;
837 			d->r[j] = d->r[i];
838 			STATS_INC(d->delete_moves);
839 			break;
840 		}
841 
842 	}
843 }
844 
845 /*
846  * Allocate a page of chunks
847  */
848 static struct chunk_info *
849 omalloc_make_chunks(struct dir_info *d, int bits, int listnum)
850 {
851 	struct chunk_info *bp;
852 	void		*pp;
853 	int		i, k;
854 
855 	/* Allocate a new bucket */
856 	pp = map(d, NULL, MALLOC_PAGESIZE, 0);
857 	if (pp == MAP_FAILED)
858 		return NULL;
859 
860 	bp = alloc_chunk_info(d, bits);
861 	if (bp == NULL) {
862 		unmap(d, pp, MALLOC_PAGESIZE, 0);
863 		return NULL;
864 	}
865 
866 	/* memory protect the page allocated in the malloc(0) case */
867 	if (bits == 0) {
868 		bp->size = 0;
869 		bp->shift = 1;
870 		i = MALLOC_MINSIZE - 1;
871 		while (i >>= 1)
872 			bp->shift++;
873 		bp->total = bp->free = MALLOC_PAGESIZE >> bp->shift;
874 		bp->offset = 0xdead;
875 		bp->page = pp;
876 
877 		k = mprotect(pp, MALLOC_PAGESIZE, PROT_NONE);
878 		if (k < 0) {
879 			unmap(d, pp, MALLOC_PAGESIZE, 0);
880 			LIST_INSERT_HEAD(&d->chunk_info_list[0], bp, entries);
881 			return NULL;
882 		}
883 	} else {
884 		bp->size = 1U << bits;
885 		bp->shift = bits;
886 		bp->total = bp->free = MALLOC_PAGESIZE >> bits;
887 		bp->offset = howmany(bp->total, MALLOC_BITS);
888 		bp->page = pp;
889 	}
890 
891 	/* set all valid bits in the bitmap */
892 	k = bp->total;
893 	i = 0;
894 
895 	/* Do a bunch at a time */
896 	for (; (k - i) >= MALLOC_BITS; i += MALLOC_BITS)
897 		bp->bits[i / MALLOC_BITS] = (u_short)~0U;
898 
899 	for (; i < k; i++)
900 		bp->bits[i / MALLOC_BITS] |= (u_short)1U << (i % MALLOC_BITS);
901 
902 	LIST_INSERT_HEAD(&d->chunk_dir[bits][listnum], bp, entries);
903 
904 	bits++;
905 	if ((uintptr_t)pp & bits)
906 		wrterror(d, "pp & bits %p", pp);
907 
908 	insert(d, (void *)((uintptr_t)pp | bits), (uintptr_t)bp, NULL);
909 	return bp;
910 }
911 
912 static int
913 find_chunksize(size_t size)
914 {
915 	int		i, j;
916 
917 	/* Don't bother with anything less than this */
918 	/* unless we have a malloc(0) requests */
919 	if (size != 0 && size < MALLOC_MINSIZE)
920 		size = MALLOC_MINSIZE;
921 
922 	/* Find the right bucket */
923 	if (size == 0)
924 		j = 0;
925 	else {
926 		j = MALLOC_MINSHIFT;
927 		i = (size - 1) >> (MALLOC_MINSHIFT - 1);
928 		while (i >>= 1)
929 			j++;
930 	}
931 	return j;
932 }
933 
934 /*
935  * Allocate a chunk
936  */
937 static void *
938 malloc_bytes(struct dir_info *d, size_t size, void *f)
939 {
940 	int		i, j, listnum;
941 	size_t		k;
942 	u_short		u, *lp;
943 	struct chunk_info *bp;
944 
945 	if (mopts.malloc_canary != (d->canary1 ^ (u_int32_t)(uintptr_t)d) ||
946 	    d->canary1 != ~d->canary2)
947 		wrterror(d, "internal struct corrupt");
948 
949 	j = find_chunksize(size);
950 
951 	listnum = getrbyte(d) % MALLOC_CHUNK_LISTS;
952 	/* If it's empty, make a page more of that size chunks */
953 	if ((bp = LIST_FIRST(&d->chunk_dir[j][listnum])) == NULL) {
954 		bp = omalloc_make_chunks(d, j, listnum);
955 		if (bp == NULL)
956 			return NULL;
957 	}
958 
959 	if (bp->canary != d->canary1)
960 		wrterror(d, "chunk info corrupted");
961 
962 	i = d->chunk_start;
963 	if (bp->free > 1)
964 		i += getrbyte(d);
965 	if (i >= bp->total)
966 		i &= bp->total - 1;
967 	for (;;) {
968 		for (;;) {
969 			lp = &bp->bits[i / MALLOC_BITS];
970 			if (!*lp) {
971 				i += MALLOC_BITS;
972 				i &= ~(MALLOC_BITS - 1);
973 				if (i >= bp->total)
974 					i = 0;
975 			} else
976 				break;
977 		}
978 		k = i % MALLOC_BITS;
979 		u = 1 << k;
980 		if (*lp & u)
981 			break;
982 		if (++i >= bp->total)
983 			i = 0;
984 	}
985 	d->chunk_start += i + 1;
986 #ifdef MALLOC_STATS
987 	if (i == 0) {
988 		struct region_info *r = find(d, bp->page);
989 		r->f = f;
990 	}
991 #endif
992 
993 	*lp ^= u;
994 
995 	/* If there are no more free, remove from free-list */
996 	if (!--bp->free)
997 		LIST_REMOVE(bp, entries);
998 
999 	/* Adjust to the real offset of that chunk */
1000 	k += (lp - bp->bits) * MALLOC_BITS;
1001 
1002 	if (mopts.chunk_canaries && size > 0)
1003 		bp->bits[bp->offset + k] = size;
1004 
1005 	k <<= bp->shift;
1006 
1007 	if (bp->size > 0) {
1008 		if (mopts.malloc_junk == 2)
1009 			memset((char *)bp->page + k, SOME_JUNK, bp->size);
1010 		else if (mopts.chunk_canaries)
1011 			fill_canary((char *)bp->page + k, size, bp->size);
1012 	}
1013 	return ((char *)bp->page + k);
1014 }
1015 
1016 static void
1017 fill_canary(char *ptr, size_t sz, size_t allocated)
1018 {
1019 	size_t check_sz = allocated - sz;
1020 
1021 	if (check_sz > CHUNK_CHECK_LENGTH)
1022 		check_sz = CHUNK_CHECK_LENGTH;
1023 	memset(ptr + sz, SOME_JUNK, check_sz);
1024 }
1025 
1026 static void
1027 validate_canary(struct dir_info *d, u_char *ptr, size_t sz, size_t allocated)
1028 {
1029 	size_t check_sz = allocated - sz;
1030 	u_char *p, *q;
1031 
1032 	if (check_sz > CHUNK_CHECK_LENGTH)
1033 		check_sz = CHUNK_CHECK_LENGTH;
1034 	p = ptr + sz;
1035 	q = p + check_sz;
1036 
1037 	while (p < q) {
1038 		if (*p != SOME_JUNK) {
1039 			wrterror(d, "chunk canary corrupted %p %#tx@%#zx%s",
1040 			    ptr, p - ptr, sz, *p == SOME_FREEJUNK ?
1041 			        " (double free?)" : "");
1042 		}
1043 		p++;
1044 	}
1045 }
1046 
1047 static uint32_t
1048 find_chunknum(struct dir_info *d, struct region_info *r, void *ptr, int check)
1049 {
1050 	struct chunk_info *info;
1051 	uint32_t chunknum;
1052 
1053 	info = (struct chunk_info *)r->size;
1054 	if (info->canary != d->canary1)
1055 		wrterror(d, "chunk info corrupted");
1056 
1057 	/* Find the chunk number on the page */
1058 	chunknum = ((uintptr_t)ptr & MALLOC_PAGEMASK) >> info->shift;
1059 
1060 	if ((uintptr_t)ptr & ((1U << (info->shift)) - 1))
1061 		wrterror(d, "modified chunk-pointer %p", ptr);
1062 	if (info->bits[chunknum / MALLOC_BITS] &
1063 	    (1U << (chunknum % MALLOC_BITS)))
1064 		wrterror(d, "chunk is already free %p", ptr);
1065 	if (check && info->size > 0) {
1066 		validate_canary(d, ptr, info->bits[info->offset + chunknum],
1067 		    info->size);
1068 	}
1069 	return chunknum;
1070 }
1071 
1072 /*
1073  * Free a chunk, and possibly the page it's on, if the page becomes empty.
1074  */
1075 static void
1076 free_bytes(struct dir_info *d, struct region_info *r, void *ptr)
1077 {
1078 	struct chunk_head *mp;
1079 	struct chunk_info *info;
1080 	uint32_t chunknum;
1081 	int listnum;
1082 
1083 	info = (struct chunk_info *)r->size;
1084 	chunknum = find_chunknum(d, r, ptr, 0);
1085 
1086 	info->bits[chunknum / MALLOC_BITS] |= 1U << (chunknum % MALLOC_BITS);
1087 	info->free++;
1088 
1089 	if (info->free == 1) {
1090 		/* Page became non-full */
1091 		listnum = getrbyte(d) % MALLOC_CHUNK_LISTS;
1092 		if (info->size != 0)
1093 			mp = &d->chunk_dir[info->shift][listnum];
1094 		else
1095 			mp = &d->chunk_dir[0][listnum];
1096 
1097 		LIST_INSERT_HEAD(mp, info, entries);
1098 		return;
1099 	}
1100 
1101 	if (info->free != info->total)
1102 		return;
1103 
1104 	LIST_REMOVE(info, entries);
1105 
1106 	if (info->size == 0 && !mopts.malloc_freeunmap)
1107 		mprotect(info->page, MALLOC_PAGESIZE, PROT_READ | PROT_WRITE);
1108 	unmap(d, info->page, MALLOC_PAGESIZE, 0);
1109 
1110 	delete(d, r);
1111 	if (info->size != 0)
1112 		mp = &d->chunk_info_list[info->shift];
1113 	else
1114 		mp = &d->chunk_info_list[0];
1115 	LIST_INSERT_HEAD(mp, info, entries);
1116 }
1117 
1118 
1119 
1120 static void *
1121 omalloc(struct dir_info *pool, size_t sz, int zero_fill, void *f)
1122 {
1123 	void *p;
1124 	size_t psz;
1125 
1126 	if (sz > MALLOC_MAXCHUNK) {
1127 		if (sz >= SIZE_MAX - mopts.malloc_guard - MALLOC_PAGESIZE) {
1128 			errno = ENOMEM;
1129 			return NULL;
1130 		}
1131 		sz += mopts.malloc_guard;
1132 		psz = PAGEROUND(sz);
1133 		p = map(pool, NULL, psz, zero_fill);
1134 		if (p == MAP_FAILED) {
1135 			errno = ENOMEM;
1136 			return NULL;
1137 		}
1138 		if (insert(pool, p, sz, f)) {
1139 			unmap(pool, p, psz, 0);
1140 			errno = ENOMEM;
1141 			return NULL;
1142 		}
1143 		if (mopts.malloc_guard) {
1144 			if (mprotect((char *)p + psz - mopts.malloc_guard,
1145 			    mopts.malloc_guard, PROT_NONE))
1146 				wrterror(pool, "mprotect");
1147 			STATS_ADD(pool->malloc_guarded, mopts.malloc_guard);
1148 		}
1149 
1150 		if (MALLOC_MOVE_COND(sz)) {
1151 			/* fill whole allocation */
1152 			if (mopts.malloc_junk == 2)
1153 				memset(p, SOME_JUNK, psz - mopts.malloc_guard);
1154 			/* shift towards the end */
1155 			p = MALLOC_MOVE(p, sz);
1156 			/* fill zeros if needed and overwritten above */
1157 			if (zero_fill && mopts.malloc_junk == 2)
1158 				memset(p, 0, sz - mopts.malloc_guard);
1159 		} else {
1160 			if (mopts.malloc_junk == 2) {
1161 				if (zero_fill)
1162 					memset((char *)p + sz - mopts.malloc_guard,
1163 					    SOME_JUNK, psz - sz);
1164 				else
1165 					memset(p, SOME_JUNK,
1166 					    psz - mopts.malloc_guard);
1167 			}
1168 			else if (mopts.chunk_canaries)
1169 				fill_canary(p, sz - mopts.malloc_guard,
1170 				    psz - mopts.malloc_guard);
1171 		}
1172 
1173 	} else {
1174 		/* takes care of SOME_JUNK */
1175 		p = malloc_bytes(pool, sz, f);
1176 		if (zero_fill && p != NULL && sz > 0)
1177 			memset(p, 0, sz);
1178 	}
1179 
1180 	return p;
1181 }
1182 
1183 /*
1184  * Common function for handling recursion.  Only
1185  * print the error message once, to avoid making the problem
1186  * potentially worse.
1187  */
1188 static void
1189 malloc_recurse(struct dir_info *d)
1190 {
1191 	static int noprint;
1192 
1193 	if (noprint == 0) {
1194 		noprint = 1;
1195 		wrterror(d, "recursive call");
1196 	}
1197 	d->active--;
1198 	_MALLOC_UNLOCK(d->mutex);
1199 	errno = EDEADLK;
1200 }
1201 
1202 void
1203 _malloc_init(int from_rthreads)
1204 {
1205 	int i, max;
1206 	struct dir_info *d;
1207 
1208 	_MALLOC_LOCK(0);
1209 	if (!from_rthreads && mopts.malloc_pool[0]) {
1210 		_MALLOC_UNLOCK(0);
1211 		return;
1212 	}
1213 	if (!mopts.malloc_canary)
1214 		omalloc_init();
1215 
1216 	max = from_rthreads ? _MALLOC_MUTEXES : 1;
1217 	if (((uintptr_t)&malloc_readonly & MALLOC_PAGEMASK) == 0)
1218 		mprotect(&malloc_readonly, sizeof(malloc_readonly),
1219 		     PROT_READ | PROT_WRITE);
1220 	for (i = 0; i < max; i++) {
1221 		if (mopts.malloc_pool[i])
1222 			continue;
1223 		omalloc_poolinit(&d);
1224 		d->mutex = i;
1225 		mopts.malloc_pool[i] = d;
1226 	}
1227 
1228 	if (from_rthreads)
1229 		mopts.malloc_mt = 1;
1230 	else
1231 		mopts.internal_funcs = 1;
1232 
1233 	/*
1234 	 * Options have been set and will never be reset.
1235 	 * Prevent further tampering with them.
1236 	 */
1237 	if (((uintptr_t)&malloc_readonly & MALLOC_PAGEMASK) == 0)
1238 		mprotect(&malloc_readonly, sizeof(malloc_readonly), PROT_READ);
1239 	_MALLOC_UNLOCK(0);
1240 }
1241 DEF_STRONG(_malloc_init);
1242 
1243 void *
1244 malloc(size_t size)
1245 {
1246 	void *r;
1247 	struct dir_info *d;
1248 	int saved_errno = errno;
1249 
1250 	d = getpool();
1251 	if (d == NULL) {
1252 		_malloc_init(0);
1253 		d = getpool();
1254 	}
1255 	_MALLOC_LOCK(d->mutex);
1256 	d->func = "malloc";
1257 
1258 	if (d->active++) {
1259 		malloc_recurse(d);
1260 		return NULL;
1261 	}
1262 	r = omalloc(d, size, 0, CALLER);
1263 	d->active--;
1264 	_MALLOC_UNLOCK(d->mutex);
1265 	if (r == NULL && mopts.malloc_xmalloc)
1266 		wrterror(d, "out of memory");
1267 	if (r != NULL)
1268 		errno = saved_errno;
1269 	return r;
1270 }
1271 /*DEF_STRONG(malloc);*/
1272 
1273 static void
1274 validate_junk(struct dir_info *pool, void *p)
1275 {
1276 	struct region_info *r;
1277 	size_t byte, sz;
1278 
1279 	if (p == NULL)
1280 		return;
1281 	r = find(pool, p);
1282 	if (r == NULL)
1283 		wrterror(pool, "bogus pointer in validate_junk %p", p);
1284 	REALSIZE(sz, r);
1285 	if (sz > CHUNK_CHECK_LENGTH)
1286 		sz = CHUNK_CHECK_LENGTH;
1287 	for (byte = 0; byte < sz; byte++) {
1288 		if (((unsigned char *)p)[byte] != SOME_FREEJUNK)
1289 			wrterror(pool, "use after free %p", p);
1290 	}
1291 }
1292 
1293 static void
1294 ofree(struct dir_info *argpool, void *p, int clear, int check, size_t argsz)
1295 {
1296 	struct dir_info *pool;
1297 	struct region_info *r;
1298 	size_t sz;
1299 	int i;
1300 
1301 	pool = argpool;
1302 	r = find(pool, p);
1303 	if (r == NULL) {
1304 		if (mopts.malloc_mt)  {
1305 			for (i = 0; i < _MALLOC_MUTEXES; i++) {
1306 				if (i == argpool->mutex)
1307 					continue;
1308 				pool->active--;
1309 				_MALLOC_UNLOCK(pool->mutex);
1310 				pool = mopts.malloc_pool[i];
1311 				_MALLOC_LOCK(pool->mutex);
1312 				pool->active++;
1313 				r = find(pool, p);
1314 				if (r != NULL)
1315 					break;
1316 			}
1317 		}
1318 		if (r == NULL)
1319 			wrterror(pool, "bogus pointer (double free?) %p", p);
1320 	}
1321 
1322 	REALSIZE(sz, r);
1323 	if (check) {
1324 		if (sz <= MALLOC_MAXCHUNK) {
1325 			if (mopts.chunk_canaries && sz > 0) {
1326 				struct chunk_info *info =
1327 				    (struct chunk_info *)r->size;
1328 				uint32_t chunknum =
1329 				    find_chunknum(pool, r, p, 0);
1330 
1331 				if (info->bits[info->offset + chunknum] <
1332 				    argsz)
1333 					wrterror(pool, "recorded size %hu"
1334 					    " < %zu",
1335 					    info->bits[info->offset + chunknum],
1336 					    argsz);
1337 			} else {
1338 				if (sz < argsz)
1339 					wrterror(pool, "chunk size %zu < %zu",
1340 					    sz, argsz);
1341 			}
1342 		} else if (sz - mopts.malloc_guard < argsz) {
1343 			wrterror(pool, "recorded size %zu < %zu",
1344 			    sz - mopts.malloc_guard, argsz);
1345 		}
1346 	}
1347 	if (sz > MALLOC_MAXCHUNK) {
1348 		if (!MALLOC_MOVE_COND(sz)) {
1349 			if (r->p != p)
1350 				wrterror(pool, "bogus pointer %p", p);
1351 			if (mopts.chunk_canaries)
1352 				validate_canary(pool, p,
1353 				    sz - mopts.malloc_guard,
1354 				    PAGEROUND(sz - mopts.malloc_guard));
1355 		} else {
1356 			/* shifted towards the end */
1357 			if (p != MALLOC_MOVE(r->p, sz))
1358 				wrterror(pool, "bogus moved pointer %p", p);
1359 			p = r->p;
1360 		}
1361 		if (mopts.malloc_guard) {
1362 			if (sz < mopts.malloc_guard)
1363 				wrterror(pool, "guard size");
1364 			if (!mopts.malloc_freeunmap) {
1365 				if (mprotect((char *)p + PAGEROUND(sz) -
1366 				    mopts.malloc_guard, mopts.malloc_guard,
1367 				    PROT_READ | PROT_WRITE))
1368 					wrterror(pool, "mprotect");
1369 			}
1370 			STATS_SUB(pool->malloc_guarded, mopts.malloc_guard);
1371 		}
1372 		unmap(pool, p, PAGEROUND(sz), clear);
1373 		delete(pool, r);
1374 	} else {
1375 		/* Validate and optionally canary check */
1376 		find_chunknum(pool, r, p, mopts.chunk_canaries);
1377 		if (!clear) {
1378 			void *tmp;
1379 			int i;
1380 
1381 			if (mopts.malloc_freecheck) {
1382 				for (i = 0; i <= MALLOC_DELAYED_CHUNK_MASK; i++)
1383 					if (p == pool->delayed_chunks[i])
1384 						wrterror(pool,
1385 						    "double free %p", p);
1386 			}
1387 			if (mopts.malloc_junk && sz > 0)
1388 				memset(p, SOME_FREEJUNK, sz);
1389 			i = getrbyte(pool) & MALLOC_DELAYED_CHUNK_MASK;
1390 			tmp = p;
1391 			p = pool->delayed_chunks[i];
1392 			if (tmp == p)
1393 				wrterror(pool, "double free %p", tmp);
1394 			pool->delayed_chunks[i] = tmp;
1395 			if (mopts.malloc_junk)
1396 				validate_junk(pool, p);
1397 		} else if (sz > 0)
1398 			memset(p, 0, sz);
1399 		if (p != NULL) {
1400 			r = find(pool, p);
1401 			if (r == NULL)
1402 				wrterror(pool,
1403 				    "bogus pointer (double free?) %p", p);
1404 			free_bytes(pool, r, p);
1405 		}
1406 	}
1407 
1408 	if (argpool != pool) {
1409 		pool->active--;
1410 		_MALLOC_UNLOCK(pool->mutex);
1411 		_MALLOC_LOCK(argpool->mutex);
1412 		argpool->active++;
1413 	}
1414 }
1415 
1416 void
1417 free(void *ptr)
1418 {
1419 	struct dir_info *d;
1420 	int saved_errno = errno;
1421 
1422 	/* This is legal. */
1423 	if (ptr == NULL)
1424 		return;
1425 
1426 	d = getpool();
1427 	if (d == NULL)
1428 		wrterror(d, "free() called before allocation");
1429 	_MALLOC_LOCK(d->mutex);
1430 	d->func = "free";
1431 	if (d->active++) {
1432 		malloc_recurse(d);
1433 		return;
1434 	}
1435 	ofree(d, ptr, 0, 0, 0);
1436 	d->active--;
1437 	_MALLOC_UNLOCK(d->mutex);
1438 	errno = saved_errno;
1439 }
1440 /*DEF_STRONG(free);*/
1441 
1442 static void
1443 freezero_p(void *ptr, size_t sz)
1444 {
1445 	explicit_bzero(ptr, sz);
1446 	free(ptr);
1447 }
1448 
1449 void
1450 freezero(void *ptr, size_t sz)
1451 {
1452 	struct dir_info *d;
1453 	int saved_errno = errno;
1454 
1455 	/* This is legal. */
1456 	if (ptr == NULL)
1457 		return;
1458 
1459 	if (!mopts.internal_funcs) {
1460 		freezero_p(ptr, sz);
1461 		return;
1462 	}
1463 
1464 	d = getpool();
1465 	if (d == NULL)
1466 		wrterror(d, "freezero() called before allocation");
1467 	_MALLOC_LOCK(d->mutex);
1468 	d->func = "freezero";
1469 	if (d->active++) {
1470 		malloc_recurse(d);
1471 		return;
1472 	}
1473 	ofree(d, ptr, 1, 1, sz);
1474 	d->active--;
1475 	_MALLOC_UNLOCK(d->mutex);
1476 	errno = saved_errno;
1477 }
1478 DEF_WEAK(freezero);
1479 
1480 static void *
1481 orealloc(struct dir_info *argpool, void *p, size_t newsz, void *f)
1482 {
1483 	struct dir_info *pool;
1484 	struct region_info *r;
1485 	struct chunk_info *info;
1486 	size_t oldsz, goldsz, gnewsz;
1487 	void *q, *ret;
1488 	int i;
1489 	uint32_t chunknum;
1490 
1491 	pool = argpool;
1492 
1493 	if (p == NULL)
1494 		return omalloc(pool, newsz, 0, f);
1495 
1496 	r = find(pool, p);
1497 	if (r == NULL) {
1498 		if (mopts.malloc_mt) {
1499 			for (i = 0; i < _MALLOC_MUTEXES; i++) {
1500 				if (i == argpool->mutex)
1501 					continue;
1502 				pool->active--;
1503 				_MALLOC_UNLOCK(pool->mutex);
1504 				pool = mopts.malloc_pool[i];
1505 				_MALLOC_LOCK(pool->mutex);
1506 				pool->active++;
1507 				r = find(pool, p);
1508 				if (r != NULL)
1509 					break;
1510 			}
1511 		}
1512 		if (r == NULL)
1513 			wrterror(pool, "bogus pointer (double free?) %p", p);
1514 	}
1515 	if (newsz >= SIZE_MAX - mopts.malloc_guard - MALLOC_PAGESIZE) {
1516 		errno = ENOMEM;
1517 		ret = NULL;
1518 		goto done;
1519 	}
1520 
1521 	REALSIZE(oldsz, r);
1522 	if (mopts.chunk_canaries && oldsz <= MALLOC_MAXCHUNK) {
1523 		chunknum = find_chunknum(pool, r, p, 0);
1524 		info = (struct chunk_info *)r->size;
1525 	}
1526 
1527 	goldsz = oldsz;
1528 	if (oldsz > MALLOC_MAXCHUNK) {
1529 		if (oldsz < mopts.malloc_guard)
1530 			wrterror(pool, "guard size");
1531 		oldsz -= mopts.malloc_guard;
1532 	}
1533 
1534 	gnewsz = newsz;
1535 	if (gnewsz > MALLOC_MAXCHUNK)
1536 		gnewsz += mopts.malloc_guard;
1537 
1538 	if (newsz > MALLOC_MAXCHUNK && oldsz > MALLOC_MAXCHUNK &&
1539 	    !mopts.malloc_realloc) {
1540 		/* First case: from n pages sized allocation to m pages sized
1541 		   allocation, m > n */
1542 		size_t roldsz = PAGEROUND(goldsz);
1543 		size_t rnewsz = PAGEROUND(gnewsz);
1544 
1545 		if (rnewsz > roldsz) {
1546 			/* try to extend existing region */
1547 			if (!mopts.malloc_guard) {
1548 				void *hint = (char *)r->p + roldsz;
1549 				size_t needed = rnewsz - roldsz;
1550 
1551 				STATS_INC(pool->cheap_realloc_tries);
1552 				q = map(pool, hint, needed, 0);
1553 				if (q == hint)
1554 					goto gotit;
1555 				zapcacheregion(pool, hint, needed);
1556 				q = MQUERY(hint, needed);
1557 				if (q == hint)
1558 					q = MMAPA(hint, needed);
1559 				else
1560 					q = MAP_FAILED;
1561 				if (q == hint) {
1562 gotit:
1563 					STATS_ADD(pool->malloc_used, needed);
1564 					if (mopts.malloc_junk == 2)
1565 						memset(q, SOME_JUNK, needed);
1566 					r->size = gnewsz;
1567 					if (r->p != p) {
1568 						/* old pointer is moved */
1569 						memmove(r->p, p, oldsz);
1570 						p = r->p;
1571 					}
1572 					if (mopts.chunk_canaries)
1573 						fill_canary(p, newsz,
1574 						    PAGEROUND(newsz));
1575 					STATS_SETF(r, f);
1576 					STATS_INC(pool->cheap_reallocs);
1577 					ret = p;
1578 					goto done;
1579 				} else if (q != MAP_FAILED) {
1580 					if (munmap(q, needed))
1581 						wrterror(pool, "munmap %p", q);
1582 				}
1583 			}
1584 		} else if (rnewsz < roldsz) {
1585 			/* shrink number of pages */
1586 			if (mopts.malloc_guard) {
1587 				if (mprotect((char *)r->p + roldsz -
1588 				    mopts.malloc_guard, mopts.malloc_guard,
1589 				    PROT_READ | PROT_WRITE))
1590 					wrterror(pool, "mprotect");
1591 				if (mprotect((char *)r->p + rnewsz -
1592 				    mopts.malloc_guard, mopts.malloc_guard,
1593 				    PROT_NONE))
1594 					wrterror(pool, "mprotect");
1595 			}
1596 			unmap(pool, (char *)r->p + rnewsz, roldsz - rnewsz, 0);
1597 			r->size = gnewsz;
1598 			if (MALLOC_MOVE_COND(gnewsz)) {
1599 				void *pp = MALLOC_MOVE(r->p, gnewsz);
1600 				memmove(pp, p, newsz);
1601 				p = pp;
1602 			} else if (mopts.chunk_canaries)
1603 				fill_canary(p, newsz, PAGEROUND(newsz));
1604 			STATS_SETF(r, f);
1605 			ret = p;
1606 			goto done;
1607 		} else {
1608 			/* number of pages remains the same */
1609 			void *pp = r->p;
1610 
1611 			r->size = gnewsz;
1612 			if (MALLOC_MOVE_COND(gnewsz))
1613 				pp = MALLOC_MOVE(r->p, gnewsz);
1614 			if (p != pp) {
1615 				memmove(pp, p, oldsz < newsz ? oldsz : newsz);
1616 				p = pp;
1617 			}
1618 			if (p == r->p) {
1619 				if (newsz > oldsz && mopts.malloc_junk == 2)
1620 					memset((char *)p + newsz, SOME_JUNK,
1621 					    rnewsz - mopts.malloc_guard -
1622 					    newsz);
1623 				if (mopts.chunk_canaries)
1624 					fill_canary(p, newsz, PAGEROUND(newsz));
1625 			}
1626 			STATS_SETF(r, f);
1627 			ret = p;
1628 			goto done;
1629 		}
1630 	}
1631 	if (oldsz <= MALLOC_MAXCHUNK && oldsz > 0 &&
1632 	    newsz <= MALLOC_MAXCHUNK && newsz > 0 &&
1633 	    1 << find_chunksize(newsz) == oldsz && !mopts.malloc_realloc) {
1634 		/* do not reallocate if new size fits good in existing chunk */
1635 		if (mopts.malloc_junk == 2)
1636 			memset((char *)p + newsz, SOME_JUNK, oldsz - newsz);
1637 		if (mopts.chunk_canaries) {
1638 			info->bits[info->offset + chunknum] = newsz;
1639 			fill_canary(p, newsz, info->size);
1640 		}
1641 		STATS_SETF(r, f);
1642 		ret = p;
1643 	} else if (newsz != oldsz || mopts.malloc_realloc) {
1644 		/* create new allocation */
1645 		q = omalloc(pool, newsz, 0, f);
1646 		if (q == NULL) {
1647 			ret = NULL;
1648 			goto done;
1649 		}
1650 		if (newsz != 0 && oldsz != 0)
1651 			memcpy(q, p, oldsz < newsz ? oldsz : newsz);
1652 		ofree(pool, p, 0, 0, 0);
1653 		ret = q;
1654 	} else {
1655 		/* oldsz == newsz */
1656 		if (newsz != 0)
1657 			wrterror(pool, "realloc internal inconsistency");
1658 		STATS_SETF(r, f);
1659 		ret = p;
1660 	}
1661 done:
1662 	if (argpool != pool) {
1663 		pool->active--;
1664 		_MALLOC_UNLOCK(pool->mutex);
1665 		_MALLOC_LOCK(argpool->mutex);
1666 		argpool->active++;
1667 	}
1668 	return ret;
1669 }
1670 
1671 void *
1672 realloc(void *ptr, size_t size)
1673 {
1674 	struct dir_info *d;
1675 	void *r;
1676 	int saved_errno = errno;
1677 
1678 	d = getpool();
1679 	if (d == NULL) {
1680 		_malloc_init(0);
1681 		d = getpool();
1682 	}
1683 	_MALLOC_LOCK(d->mutex);
1684 	d->func = "realloc";
1685 	if (d->active++) {
1686 		malloc_recurse(d);
1687 		return NULL;
1688 	}
1689 	r = orealloc(d, ptr, size, CALLER);
1690 
1691 	d->active--;
1692 	_MALLOC_UNLOCK(d->mutex);
1693 	if (r == NULL && mopts.malloc_xmalloc)
1694 		wrterror(d, "out of memory");
1695 	if (r != NULL)
1696 		errno = saved_errno;
1697 	return r;
1698 }
1699 /*DEF_STRONG(realloc);*/
1700 
1701 
1702 /*
1703  * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX
1704  * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW
1705  */
1706 #define MUL_NO_OVERFLOW	(1UL << (sizeof(size_t) * 4))
1707 
1708 void *
1709 calloc(size_t nmemb, size_t size)
1710 {
1711 	struct dir_info *d;
1712 	void *r;
1713 	int saved_errno = errno;
1714 
1715 	d = getpool();
1716 	if (d == NULL) {
1717 		_malloc_init(0);
1718 		d = getpool();
1719 	}
1720 	_MALLOC_LOCK(d->mutex);
1721 	d->func = "calloc";
1722 	if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
1723 	    nmemb > 0 && SIZE_MAX / nmemb < size) {
1724 		_MALLOC_UNLOCK(d->mutex);
1725 		if (mopts.malloc_xmalloc)
1726 			wrterror(d, "out of memory");
1727 		errno = ENOMEM;
1728 		return NULL;
1729 	}
1730 
1731 	if (d->active++) {
1732 		malloc_recurse(d);
1733 		return NULL;
1734 	}
1735 
1736 	size *= nmemb;
1737 	r = omalloc(d, size, 1, CALLER);
1738 
1739 	d->active--;
1740 	_MALLOC_UNLOCK(d->mutex);
1741 	if (r == NULL && mopts.malloc_xmalloc)
1742 		wrterror(d, "out of memory");
1743 	if (r != NULL)
1744 		errno = saved_errno;
1745 	return r;
1746 }
1747 /*DEF_STRONG(calloc);*/
1748 
1749 static void *
1750 orecallocarray(struct dir_info *argpool, void *p, size_t oldsize,
1751     size_t newsize, void *f)
1752 {
1753 	struct dir_info *pool;
1754 	struct region_info *r;
1755 	void *newptr;
1756 	size_t sz;
1757 	int i;
1758 
1759 	pool = argpool;
1760 
1761 	if (p == NULL)
1762 		return omalloc(pool, newsize, 1, f);
1763 
1764 	if (oldsize == newsize)
1765 		return p;
1766 
1767 	r = find(pool, p);
1768 	if (r == NULL) {
1769 		if (mopts.malloc_mt) {
1770 			for (i = 0; i < _MALLOC_MUTEXES; i++) {
1771 				if (i == argpool->mutex)
1772 					continue;
1773 				pool->active--;
1774 				_MALLOC_UNLOCK(pool->mutex);
1775 				pool = mopts.malloc_pool[i];
1776 				_MALLOC_LOCK(pool->mutex);
1777 				pool->active++;
1778 				r = find(pool, p);
1779 				if (r != NULL)
1780 					break;
1781 			}
1782 		}
1783 		if (r == NULL)
1784 			wrterror(pool, "bogus pointer (double free?) %p", p);
1785 	}
1786 
1787 	REALSIZE(sz, r);
1788 	if (sz <= MALLOC_MAXCHUNK) {
1789 		if (mopts.chunk_canaries && sz > 0) {
1790 			struct chunk_info *info = (struct chunk_info *)r->size;
1791 			uint32_t chunknum = find_chunknum(pool, r, p, 0);
1792 
1793 			if (info->bits[info->offset + chunknum] != oldsize)
1794 				wrterror(pool, "recorded old size %hu != %zu",
1795 				    info->bits[info->offset + chunknum],
1796 				    oldsize);
1797 		}
1798 	} else if (oldsize != sz - mopts.malloc_guard)
1799 		wrterror(pool, "recorded old size %zu != %zu",
1800 		    sz - mopts.malloc_guard, oldsize);
1801 
1802 	newptr = omalloc(pool, newsize, 0, f);
1803 	if (newptr == NULL)
1804 		goto done;
1805 
1806 	if (newsize > oldsize) {
1807 		memcpy(newptr, p, oldsize);
1808 		memset((char *)newptr + oldsize, 0, newsize - oldsize);
1809 	} else
1810 		memcpy(newptr, p, newsize);
1811 
1812 	ofree(pool, p, 1, 0, 0);
1813 
1814 done:
1815 	if (argpool != pool) {
1816 		pool->active--;
1817 		_MALLOC_UNLOCK(pool->mutex);
1818 		_MALLOC_LOCK(argpool->mutex);
1819 		argpool->active++;
1820 	}
1821 
1822 	return newptr;
1823 }
1824 
1825 static void *
1826 recallocarray_p(void *ptr, size_t oldnmemb, size_t newnmemb, size_t size)
1827 {
1828 	size_t oldsize, newsize;
1829 	void *newptr;
1830 
1831 	if (ptr == NULL)
1832 		return calloc(newnmemb, size);
1833 
1834 	if ((newnmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
1835 	    newnmemb > 0 && SIZE_MAX / newnmemb < size) {
1836 		errno = ENOMEM;
1837 		return NULL;
1838 	}
1839 	newsize = newnmemb * size;
1840 
1841 	if ((oldnmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
1842 	    oldnmemb > 0 && SIZE_MAX / oldnmemb < size) {
1843 		errno = EINVAL;
1844 		return NULL;
1845 	}
1846 	oldsize = oldnmemb * size;
1847 
1848 	/*
1849 	 * Don't bother too much if we're shrinking just a bit,
1850 	 * we do not shrink for series of small steps, oh well.
1851 	 */
1852 	if (newsize <= oldsize) {
1853 		size_t d = oldsize - newsize;
1854 
1855 		if (d < oldsize / 2 && d < MALLOC_PAGESIZE) {
1856 			memset((char *)ptr + newsize, 0, d);
1857 			return ptr;
1858 		}
1859 	}
1860 
1861 	newptr = malloc(newsize);
1862 	if (newptr == NULL)
1863 		return NULL;
1864 
1865 	if (newsize > oldsize) {
1866 		memcpy(newptr, ptr, oldsize);
1867 		memset((char *)newptr + oldsize, 0, newsize - oldsize);
1868 	} else
1869 		memcpy(newptr, ptr, newsize);
1870 
1871 	explicit_bzero(ptr, oldsize);
1872 	free(ptr);
1873 
1874 	return newptr;
1875 }
1876 
1877 void *
1878 recallocarray(void *ptr, size_t oldnmemb, size_t newnmemb, size_t size)
1879 {
1880 	struct dir_info *d;
1881 	size_t oldsize = 0, newsize;
1882 	void *r;
1883 	int saved_errno = errno;
1884 
1885 	if (!mopts.internal_funcs)
1886 		return recallocarray_p(ptr, oldnmemb, newnmemb, size);
1887 
1888 	d = getpool();
1889 	if (d == NULL) {
1890 		_malloc_init(0);
1891 		d = getpool();
1892 	}
1893 
1894 	_MALLOC_LOCK(d->mutex);
1895 	d->func = "recallocarray";
1896 
1897 	if ((newnmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
1898 	    newnmemb > 0 && SIZE_MAX / newnmemb < size) {
1899 		_MALLOC_UNLOCK(d->mutex);
1900 		if (mopts.malloc_xmalloc)
1901 			wrterror(d, "out of memory");
1902 		errno = ENOMEM;
1903 		return NULL;
1904 	}
1905 	newsize = newnmemb * size;
1906 
1907 	if (ptr != NULL) {
1908 		if ((oldnmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
1909 		    oldnmemb > 0 && SIZE_MAX / oldnmemb < size) {
1910 			_MALLOC_UNLOCK(d->mutex);
1911 			errno = EINVAL;
1912 			return NULL;
1913 		}
1914 		oldsize = oldnmemb * size;
1915 	}
1916 
1917 	if (d->active++) {
1918 		malloc_recurse(d);
1919 		return NULL;
1920 	}
1921 
1922 	r = orecallocarray(d, ptr, oldsize, newsize, CALLER);
1923 
1924 	d->active--;
1925 	_MALLOC_UNLOCK(d->mutex);
1926 	if (r == NULL && mopts.malloc_xmalloc)
1927 		wrterror(d, "out of memory");
1928 	if (r != NULL)
1929 		errno = saved_errno;
1930 	return r;
1931 }
1932 DEF_WEAK(recallocarray);
1933 
1934 
1935 static void *
1936 mapalign(struct dir_info *d, size_t alignment, size_t sz, int zero_fill)
1937 {
1938 	char *p, *q;
1939 
1940 	if (alignment < MALLOC_PAGESIZE || ((alignment - 1) & alignment) != 0)
1941 		wrterror(d, "mapalign bad alignment");
1942 	if (sz != PAGEROUND(sz))
1943 		wrterror(d, "mapalign round");
1944 
1945 	/* Allocate sz + alignment bytes of memory, which must include a
1946 	 * subrange of size bytes that is properly aligned.  Unmap the
1947 	 * other bytes, and then return that subrange.
1948 	 */
1949 
1950 	/* We need sz + alignment to fit into a size_t. */
1951 	if (alignment > SIZE_MAX - sz)
1952 		return MAP_FAILED;
1953 
1954 	p = map(d, NULL, sz + alignment, zero_fill);
1955 	if (p == MAP_FAILED)
1956 		return MAP_FAILED;
1957 	q = (char *)(((uintptr_t)p + alignment - 1) & ~(alignment - 1));
1958 	if (q != p) {
1959 		if (munmap(p, q - p))
1960 			wrterror(d, "munmap %p", p);
1961 	}
1962 	if (munmap(q + sz, alignment - (q - p)))
1963 		wrterror(d, "munmap %p", q + sz);
1964 	STATS_SUB(d->malloc_used, alignment);
1965 
1966 	return q;
1967 }
1968 
1969 static void *
1970 omemalign(struct dir_info *pool, size_t alignment, size_t sz, int zero_fill,
1971     void *f)
1972 {
1973 	size_t psz;
1974 	void *p;
1975 
1976 	/* If between half a page and a page, avoid MALLOC_MOVE. */
1977 	if (sz > MALLOC_MAXCHUNK && sz < MALLOC_PAGESIZE)
1978 		sz = MALLOC_PAGESIZE;
1979 	if (alignment <= MALLOC_PAGESIZE) {
1980 		/*
1981 		 * max(size, alignment) is enough to assure the requested
1982 		 * alignment, since the allocator always allocates
1983 		 * power-of-two blocks.
1984 		 */
1985 		if (sz < alignment)
1986 			sz = alignment;
1987 		return omalloc(pool, sz, zero_fill, f);
1988 	}
1989 
1990 	if (sz >= SIZE_MAX - mopts.malloc_guard - MALLOC_PAGESIZE) {
1991 		errno = ENOMEM;
1992 		return NULL;
1993 	}
1994 
1995 	sz += mopts.malloc_guard;
1996 	psz = PAGEROUND(sz);
1997 
1998 	p = mapalign(pool, alignment, psz, zero_fill);
1999 	if (p == MAP_FAILED) {
2000 		errno = ENOMEM;
2001 		return NULL;
2002 	}
2003 
2004 	if (insert(pool, p, sz, f)) {
2005 		unmap(pool, p, psz, 0);
2006 		errno = ENOMEM;
2007 		return NULL;
2008 	}
2009 
2010 	if (mopts.malloc_guard) {
2011 		if (mprotect((char *)p + psz - mopts.malloc_guard,
2012 		    mopts.malloc_guard, PROT_NONE))
2013 			wrterror(pool, "mprotect");
2014 		STATS_ADD(pool->malloc_guarded, mopts.malloc_guard);
2015 	}
2016 
2017 	if (mopts.malloc_junk == 2) {
2018 		if (zero_fill)
2019 			memset((char *)p + sz - mopts.malloc_guard,
2020 			    SOME_JUNK, psz - sz);
2021 		else
2022 			memset(p, SOME_JUNK, psz - mopts.malloc_guard);
2023 	}
2024 	else if (mopts.chunk_canaries)
2025 		fill_canary(p, sz - mopts.malloc_guard,
2026 		    psz - mopts.malloc_guard);
2027 
2028 	return p;
2029 }
2030 
2031 int
2032 posix_memalign(void **memptr, size_t alignment, size_t size)
2033 {
2034 	struct dir_info *d;
2035 	int res, saved_errno = errno;
2036 	void *r;
2037 
2038 	/* Make sure that alignment is a large enough power of 2. */
2039 	if (((alignment - 1) & alignment) != 0 || alignment < sizeof(void *))
2040 		return EINVAL;
2041 
2042 	d = getpool();
2043 	if (d == NULL) {
2044 		_malloc_init(0);
2045 		d = getpool();
2046 	}
2047 	_MALLOC_LOCK(d->mutex);
2048 	d->func = "posix_memalign";
2049 	if (d->active++) {
2050 		malloc_recurse(d);
2051 		goto err;
2052 	}
2053 	r = omemalign(d, alignment, size, 0, CALLER);
2054 	d->active--;
2055 	_MALLOC_UNLOCK(d->mutex);
2056 	if (r == NULL) {
2057 		if (mopts.malloc_xmalloc)
2058 			wrterror(d, "out of memory");
2059 		goto err;
2060 	}
2061 	errno = saved_errno;
2062 	*memptr = r;
2063 	return 0;
2064 
2065 err:
2066 	res = errno;
2067 	errno = saved_errno;
2068 	return res;
2069 }
2070 /*DEF_STRONG(posix_memalign);*/
2071 
2072 #ifdef MALLOC_STATS
2073 
2074 struct malloc_leak {
2075 	void *f;
2076 	size_t total_size;
2077 	int count;
2078 };
2079 
2080 struct leaknode {
2081 	RBT_ENTRY(leaknode) entry;
2082 	struct malloc_leak d;
2083 };
2084 
2085 static inline int
2086 leakcmp(const struct leaknode *e1, const struct leaknode *e2)
2087 {
2088 	return e1->d.f < e2->d.f ? -1 : e1->d.f > e2->d.f;
2089 }
2090 
2091 static RBT_HEAD(leaktree, leaknode) leakhead;
2092 RBT_PROTOTYPE(leaktree, leaknode, entry, leakcmp);
2093 RBT_GENERATE(leaktree, leaknode, entry, leakcmp);
2094 
2095 static void
2096 putleakinfo(void *f, size_t sz, int cnt)
2097 {
2098 	struct leaknode key, *p;
2099 	static struct leaknode *page;
2100 	static int used;
2101 
2102 	if (cnt == 0 || page == MAP_FAILED)
2103 		return;
2104 
2105 	key.d.f = f;
2106 	p = RBT_FIND(leaktree, &leakhead, &key);
2107 	if (p == NULL) {
2108 		if (page == NULL ||
2109 		    used >= MALLOC_PAGESIZE / sizeof(struct leaknode)) {
2110 			page = MMAP(MALLOC_PAGESIZE);
2111 			if (page == MAP_FAILED)
2112 				return;
2113 			used = 0;
2114 		}
2115 		p = &page[used++];
2116 		p->d.f = f;
2117 		p->d.total_size = sz * cnt;
2118 		p->d.count = cnt;
2119 		RBT_INSERT(leaktree, &leakhead, p);
2120 	} else {
2121 		p->d.total_size += sz * cnt;
2122 		p->d.count += cnt;
2123 	}
2124 }
2125 
2126 static struct malloc_leak *malloc_leaks;
2127 
2128 static void
2129 dump_leaks(int fd)
2130 {
2131 	struct leaknode *p;
2132 	int i = 0;
2133 
2134 	dprintf(fd, "Leak report\n");
2135 	dprintf(fd, "                 f     sum      #    avg\n");
2136 	/* XXX only one page of summary */
2137 	if (malloc_leaks == NULL)
2138 		malloc_leaks = MMAP(MALLOC_PAGESIZE);
2139 	if (malloc_leaks != MAP_FAILED)
2140 		memset(malloc_leaks, 0, MALLOC_PAGESIZE);
2141 	RBT_FOREACH(p, leaktree, &leakhead) {
2142 		dprintf(fd, "%18p %7zu %6u %6zu\n", p->d.f,
2143 		    p->d.total_size, p->d.count, p->d.total_size / p->d.count);
2144 		if (malloc_leaks == MAP_FAILED ||
2145 		    i >= MALLOC_PAGESIZE / sizeof(struct malloc_leak))
2146 			continue;
2147 		malloc_leaks[i].f = p->d.f;
2148 		malloc_leaks[i].total_size = p->d.total_size;
2149 		malloc_leaks[i].count = p->d.count;
2150 		i++;
2151 	}
2152 }
2153 
2154 static void
2155 dump_chunk(int fd, struct chunk_info *p, void *f, int fromfreelist)
2156 {
2157 	while (p != NULL) {
2158 		dprintf(fd, "chunk %18p %18p %4d %d/%d\n",
2159 		    p->page, ((p->bits[0] & 1) ? NULL : f),
2160 		    p->size, p->free, p->total);
2161 		if (!fromfreelist) {
2162 			if (p->bits[0] & 1)
2163 				putleakinfo(NULL, p->size, p->total - p->free);
2164 			else {
2165 				putleakinfo(f, p->size, 1);
2166 				putleakinfo(NULL, p->size,
2167 				    p->total - p->free - 1);
2168 			}
2169 			break;
2170 		}
2171 		p = LIST_NEXT(p, entries);
2172 		if (p != NULL)
2173 			dprintf(fd, "        ");
2174 	}
2175 }
2176 
2177 static void
2178 dump_free_chunk_info(int fd, struct dir_info *d)
2179 {
2180 	int i, j, count;
2181 	struct chunk_info *p;
2182 
2183 	dprintf(fd, "Free chunk structs:\n");
2184 	for (i = 0; i <= MALLOC_MAXSHIFT; i++) {
2185 		count = 0;
2186 		LIST_FOREACH(p, &d->chunk_info_list[i], entries)
2187 			count++;
2188 		for (j = 0; j < MALLOC_CHUNK_LISTS; j++) {
2189 			p = LIST_FIRST(&d->chunk_dir[i][j]);
2190 			if (p == NULL && count == 0)
2191 				continue;
2192 			dprintf(fd, "%2d) %3d ", i, count);
2193 			if (p != NULL)
2194 				dump_chunk(fd, p, NULL, 1);
2195 			else
2196 				dprintf(fd, "\n");
2197 		}
2198 	}
2199 
2200 }
2201 
2202 static void
2203 dump_free_page_info(int fd, struct dir_info *d)
2204 {
2205 	int i;
2206 
2207 	dprintf(fd, "Free pages cached: %zu\n", d->free_regions_size);
2208 	for (i = 0; i < mopts.malloc_cache; i++) {
2209 		if (d->free_regions[i].p != NULL) {
2210 			dprintf(fd, "%2d) ", i);
2211 			dprintf(fd, "free at %p: %zu\n",
2212 			    d->free_regions[i].p, d->free_regions[i].size);
2213 		}
2214 	}
2215 }
2216 
2217 static void
2218 malloc_dump1(int fd, int poolno, struct dir_info *d)
2219 {
2220 	size_t i, realsize;
2221 
2222 	dprintf(fd, "Malloc dir of %s pool %d at %p\n", __progname, poolno, d);
2223 	if (d == NULL)
2224 		return;
2225 	dprintf(fd, "Region slots free %zu/%zu\n",
2226 		d->regions_free, d->regions_total);
2227 	dprintf(fd, "Finds %zu/%zu\n", d->finds,
2228 	    d->find_collisions);
2229 	dprintf(fd, "Inserts %zu/%zu\n", d->inserts,
2230 	    d->insert_collisions);
2231 	dprintf(fd, "Deletes %zu/%zu\n", d->deletes,
2232 	    d->delete_moves);
2233 	dprintf(fd, "Cheap reallocs %zu/%zu\n",
2234 	    d->cheap_reallocs, d->cheap_realloc_tries);
2235 	dprintf(fd, "In use %zu\n", d->malloc_used);
2236 	dprintf(fd, "Guarded %zu\n", d->malloc_guarded);
2237 	dump_free_chunk_info(fd, d);
2238 	dump_free_page_info(fd, d);
2239 	dprintf(fd,
2240 	    "slot)  hash d  type               page                  f size [free/n]\n");
2241 	for (i = 0; i < d->regions_total; i++) {
2242 		if (d->r[i].p != NULL) {
2243 			size_t h = hash(d->r[i].p) &
2244 			    (d->regions_total - 1);
2245 			dprintf(fd, "%4zx) #%4zx %zd ",
2246 			    i, h, h - i);
2247 			REALSIZE(realsize, &d->r[i]);
2248 			if (realsize > MALLOC_MAXCHUNK) {
2249 				putleakinfo(d->r[i].f, realsize, 1);
2250 				dprintf(fd,
2251 				    "pages %18p %18p %zu\n", d->r[i].p,
2252 				    d->r[i].f, realsize);
2253 			} else
2254 				dump_chunk(fd,
2255 				    (struct chunk_info *)d->r[i].size,
2256 				    d->r[i].f, 0);
2257 		}
2258 	}
2259 	dump_leaks(fd);
2260 	dprintf(fd, "\n");
2261 }
2262 
2263 void
2264 malloc_dump(int fd, int poolno, struct dir_info *pool)
2265 {
2266 	int i;
2267 	void *p;
2268 	struct region_info *r;
2269 	int saved_errno = errno;
2270 
2271 	if (pool == NULL)
2272 		return;
2273 	for (i = 0; i < MALLOC_DELAYED_CHUNK_MASK + 1; i++) {
2274 		p = pool->delayed_chunks[i];
2275 		if (p == NULL)
2276 			continue;
2277 		r = find(pool, p);
2278 		if (r == NULL)
2279 			wrterror(pool, "bogus pointer in malloc_dump %p", p);
2280 		free_bytes(pool, r, p);
2281 		pool->delayed_chunks[i] = NULL;
2282 	}
2283 	/* XXX leak when run multiple times */
2284 	RBT_INIT(leaktree, &leakhead);
2285 	malloc_dump1(fd, poolno, pool);
2286 	errno = saved_errno;
2287 }
2288 DEF_WEAK(malloc_dump);
2289 
2290 void
2291 malloc_gdump(int fd)
2292 {
2293 	int i;
2294 	int saved_errno = errno;
2295 
2296 	for (i = 0; i < _MALLOC_MUTEXES; i++)
2297 		malloc_dump(fd, i, mopts.malloc_pool[i]);
2298 
2299 	errno = saved_errno;
2300 }
2301 DEF_WEAK(malloc_gdump);
2302 
2303 static void
2304 malloc_exit(void)
2305 {
2306 	int save_errno = errno, fd, i;
2307 
2308 	fd = open("malloc.out", O_RDWR|O_APPEND);
2309 	if (fd != -1) {
2310 		dprintf(fd, "******** Start dump %s *******\n", __progname);
2311 		dprintf(fd,
2312 		    "MT=%d I=%d F=%d U=%d J=%d R=%d X=%d C=%d cache=%u G=%zu\n",
2313 		    mopts.malloc_mt, mopts.internal_funcs,
2314 		    mopts.malloc_freecheck,
2315 		    mopts.malloc_freeunmap, mopts.malloc_junk,
2316 		    mopts.malloc_realloc, mopts.malloc_xmalloc,
2317 		    mopts.chunk_canaries, mopts.malloc_cache,
2318 		    mopts.malloc_guard);
2319 
2320 		for (i = 0; i < _MALLOC_MUTEXES; i++)
2321 			malloc_dump(fd, i, mopts.malloc_pool[i]);
2322 		dprintf(fd, "******** End dump %s *******\n", __progname);
2323 		close(fd);
2324 	} else
2325 		dprintf(STDERR_FILENO,
2326 		    "malloc() warning: Couldn't dump stats\n");
2327 	errno = save_errno;
2328 }
2329 
2330 #endif /* MALLOC_STATS */
2331