xref: /openbsd-src/sys/kern/kern_malloc.c (revision 43003dfe3ad45d1698bed8a37f2b0f5b14f20d4f)
1 /*	$OpenBSD: kern_malloc.c,v 1.81 2009/08/25 18:02:42 miod Exp $	*/
2 /*	$NetBSD: kern_malloc.c,v 1.15.4.2 1996/06/13 17:10:56 cgd Exp $	*/
3 
4 /*
5  * Copyright (c) 1987, 1991, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  *	@(#)kern_malloc.c	8.3 (Berkeley) 1/4/94
33  */
34 
35 #include <sys/param.h>
36 #include <sys/proc.h>
37 #include <sys/kernel.h>
38 #include <sys/malloc.h>
39 #include <sys/systm.h>
40 #include <sys/sysctl.h>
41 #include <sys/time.h>
42 #include <sys/rwlock.h>
43 
44 #include <uvm/uvm_extern.h>
45 
46 static __inline__ long BUCKETINDX(size_t sz)
47 {
48 #ifdef SMALL_KERNEL
49 	long b;
50 
51 	if (sz-- == 0)
52 		return MINBUCKET;
53 
54 	for (b = MINBUCKET; b < MINBUCKET + 15; b++)
55 		if ((sz >> b) == 0)
56 			break;
57 #else
58 	long b, d;
59 
60 	/* note that this relies upon MINALLOCSIZE being 1 << MINBUCKET */
61 	b = 7 + MINBUCKET; d = 4;
62 	while (d != 0) {
63 		if (sz <= (1 << b))
64 			b -= d;
65 		else
66 			b += d;
67 		d >>= 1;
68 	}
69 	if (sz <= (1 << b))
70 		b += 0;
71 	else
72 		b += 1;
73 #endif
74 
75 	return b;
76 }
77 
78 static struct vm_map kmem_map_store;
79 struct vm_map *kmem_map = NULL;
80 
81 #ifdef NKMEMCLUSTERS
82 #error NKMEMCLUSTERS is obsolete; remove it from your kernel config file and use NKMEMPAGES instead or let the kernel auto-size
83 #endif
84 
85 /*
86  * Default number of pages in kmem_map.  We attempt to calculate this
87  * at run-time, but allow it to be either patched or set in the kernel
88  * config file.
89  */
90 #ifndef NKMEMPAGES
91 #define	NKMEMPAGES	0
92 #endif
93 u_int	nkmempages = NKMEMPAGES;
94 
95 /*
96  * Defaults for lower- and upper-bounds for the kmem_map page count.
97  * Can be overridden by kernel config options.
98  */
99 #ifndef	NKMEMPAGES_MIN
100 #define	NKMEMPAGES_MIN	0
101 #endif
102 u_int	nkmempages_min = 0;
103 
104 #ifndef NKMEMPAGES_MAX
105 #define	NKMEMPAGES_MAX	NKMEMPAGES_MAX_DEFAULT
106 #endif
107 u_int	nkmempages_max = 0;
108 
109 struct kmembuckets bucket[MINBUCKET + 16];
110 struct kmemstats kmemstats[M_LAST];
111 struct kmemusage *kmemusage;
112 char *kmembase, *kmemlimit;
113 char buckstring[16 * sizeof("123456,")];
114 int buckstring_init = 0;
115 #if defined(KMEMSTATS) || defined(DIAGNOSTIC) || defined(FFS_SOFTUPDATES)
116 char *memname[] = INITKMEMNAMES;
117 char *memall = NULL;
118 struct rwlock sysctl_kmemlock = RWLOCK_INITIALIZER("sysctlklk");
119 #endif
120 
121 #ifdef DIAGNOSTIC
122 /*
123  * This structure provides a set of masks to catch unaligned frees.
124  */
125 const long addrmask[] = { 0,
126 	0x00000001, 0x00000003, 0x00000007, 0x0000000f,
127 	0x0000001f, 0x0000003f, 0x0000007f, 0x000000ff,
128 	0x000001ff, 0x000003ff, 0x000007ff, 0x00000fff,
129 	0x00001fff, 0x00003fff, 0x00007fff, 0x0000ffff,
130 };
131 
132 /*
133  * The WEIRD_ADDR is used as known text to copy into free objects so
134  * that modifications after frees can be detected.
135  */
136 #ifdef DEADBEEF0
137 #define WEIRD_ADDR	((unsigned) DEADBEEF0)
138 #else
139 #define WEIRD_ADDR	((unsigned) 0xdeadbeef)
140 #endif
141 #define MAX_COPY	32
142 
143 /*
144  * Normally the freelist structure is used only to hold the list pointer
145  * for free objects.  However, when running with diagnostics, the first
146  * 8 bytes of the structure is unused except for diagnostic information,
147  * and the free list pointer is at offset 8 in the structure.  Since the
148  * first 8 bytes is the portion of the structure most often modified, this
149  * helps to detect memory reuse problems and avoid free list corruption.
150  */
151 struct freelist {
152 	int32_t	spare0;
153 	int16_t	type;
154 	int16_t	spare1;
155 	caddr_t	next;
156 };
157 #else /* !DIAGNOSTIC */
158 struct freelist {
159 	caddr_t	next;
160 };
161 #endif /* DIAGNOSTIC */
162 
163 #ifndef SMALL_KERNEL
164 struct timeval malloc_errintvl = { 5, 0 };
165 struct timeval malloc_lasterr;
166 #endif
167 
168 /*
169  * Allocate a block of memory
170  */
171 void *
172 malloc(unsigned long size, int type, int flags)
173 {
174 	struct kmembuckets *kbp;
175 	struct kmemusage *kup;
176 	struct freelist *freep;
177 	long indx, npg, allocsize;
178 	int s;
179 	caddr_t va, cp, savedlist;
180 #ifdef DIAGNOSTIC
181 	int32_t *end, *lp;
182 	int copysize, freshalloc;
183 	char *savedtype;
184 #endif
185 #ifdef KMEMSTATS
186 	struct kmemstats *ksp = &kmemstats[type];
187 
188 	if (((unsigned long)type) >= M_LAST)
189 		panic("malloc - bogus type");
190 #endif
191 
192 #ifdef MALLOC_DEBUG
193 	if (debug_malloc(size, type, flags, (void **)&va)) {
194 		if ((flags & M_ZERO) && va != NULL)
195 			memset(va, 0, size);
196 		return (va);
197 	}
198 #endif
199 
200 	if (size > 65535 * PAGE_SIZE) {
201 		if (flags & M_CANFAIL) {
202 #ifndef SMALL_KERNEL
203 			if (ratecheck(&malloc_lasterr, &malloc_errintvl))
204 				printf("malloc(): allocation too large, "
205 				    "type = %d, size = %lu\n", type, size);
206 #endif
207 			return (NULL);
208 		} else
209 			panic("malloc: allocation too large");
210 	}
211 
212 	indx = BUCKETINDX(size);
213 	kbp = &bucket[indx];
214 	s = splvm();
215 #ifdef KMEMSTATS
216 	while (ksp->ks_memuse >= ksp->ks_limit) {
217 		if (flags & M_NOWAIT) {
218 			splx(s);
219 			return (NULL);
220 		}
221 		if (ksp->ks_limblocks < 65535)
222 			ksp->ks_limblocks++;
223 		tsleep(ksp, PSWP+2, memname[type], 0);
224 	}
225 	ksp->ks_size |= 1 << indx;
226 #endif
227 #ifdef DIAGNOSTIC
228 	copysize = 1 << indx < MAX_COPY ? 1 << indx : MAX_COPY;
229 #endif
230 	if (kbp->kb_next == NULL) {
231 		if (size > MAXALLOCSAVE)
232 			allocsize = round_page(size);
233 		else
234 			allocsize = 1 << indx;
235 		npg = atop(round_page(allocsize));
236 		va = (caddr_t) uvm_km_kmemalloc(kmem_map, NULL,
237 		    (vsize_t)ptoa(npg),
238 		    ((flags & M_NOWAIT) ? UVM_KMF_NOWAIT : 0) |
239 		    ((flags & M_CANFAIL) ? UVM_KMF_CANFAIL : 0));
240 		if (va == NULL) {
241 			/*
242 			 * Kmem_malloc() can return NULL, even if it can
243 			 * wait, if there is no map space available, because
244 			 * it can't fix that problem.  Neither can we,
245 			 * right now.  (We should release pages which
246 			 * are completely free and which are in buckets
247 			 * with too many free elements.)
248 			 */
249 			if ((flags & (M_NOWAIT|M_CANFAIL)) == 0)
250 				panic("malloc: out of space in kmem_map");
251 			splx(s);
252 			return (NULL);
253 		}
254 #ifdef KMEMSTATS
255 		kbp->kb_total += kbp->kb_elmpercl;
256 #endif
257 		kup = btokup(va);
258 		kup->ku_indx = indx;
259 #ifdef DIAGNOSTIC
260 		freshalloc = 1;
261 #endif
262 		if (allocsize > MAXALLOCSAVE) {
263 			kup->ku_pagecnt = npg;
264 #ifdef KMEMSTATS
265 			ksp->ks_memuse += allocsize;
266 #endif
267 			goto out;
268 		}
269 #ifdef KMEMSTATS
270 		kup->ku_freecnt = kbp->kb_elmpercl;
271 		kbp->kb_totalfree += kbp->kb_elmpercl;
272 #endif
273 		/*
274 		 * Just in case we blocked while allocating memory,
275 		 * and someone else also allocated memory for this
276 		 * bucket, don't assume the list is still empty.
277 		 */
278 		savedlist = kbp->kb_next;
279 		kbp->kb_next = cp = va + (npg * PAGE_SIZE) - allocsize;
280 		for (;;) {
281 			freep = (struct freelist *)cp;
282 #ifdef DIAGNOSTIC
283 			/*
284 			 * Copy in known text to detect modification
285 			 * after freeing.
286 			 */
287 			end = (int32_t *)&cp[copysize];
288 			for (lp = (int32_t *)cp; lp < end; lp++)
289 				*lp = WEIRD_ADDR;
290 			freep->type = M_FREE;
291 #endif /* DIAGNOSTIC */
292 			if (cp <= va)
293 				break;
294 			cp -= allocsize;
295 			freep->next = cp;
296 		}
297 		freep->next = savedlist;
298 		if (savedlist == NULL)
299 			kbp->kb_last = (caddr_t)freep;
300 	} else {
301 #ifdef DIAGNOSTIC
302 		freshalloc = 0;
303 #endif
304 	}
305 	va = kbp->kb_next;
306 	kbp->kb_next = ((struct freelist *)va)->next;
307 #ifdef DIAGNOSTIC
308 	freep = (struct freelist *)va;
309 	savedtype = (unsigned)freep->type < M_LAST ?
310 		memname[freep->type] : "???";
311 	if (freshalloc == 0 && kbp->kb_next) {
312 		int rv;
313 		vaddr_t addr = (vaddr_t)kbp->kb_next;
314 
315 		vm_map_lock(kmem_map);
316 		rv = uvm_map_checkprot(kmem_map, addr,
317 		    addr + sizeof(struct freelist), VM_PROT_WRITE);
318 		vm_map_unlock(kmem_map);
319 
320 		if (!rv)  {
321 			printf("%s %d of object %p size 0x%lx %s %s"
322 			    " (invalid addr %p)\n",
323 			    "Data modified on freelist: word",
324 			    (int32_t *)&kbp->kb_next - (int32_t *)kbp, va, size,
325 			    "previous type", savedtype, addr);
326 			kbp->kb_next = NULL;
327 		}
328 	}
329 
330 	/* Fill the fields that we've used with WEIRD_ADDR */
331 #if BYTE_ORDER == BIG_ENDIAN
332 	freep->type = WEIRD_ADDR >> 16;
333 #endif
334 #if BYTE_ORDER == LITTLE_ENDIAN
335 	freep->type = (short)WEIRD_ADDR;
336 #endif
337 	end = (int32_t *)&freep->next +
338 	    (sizeof(freep->next) / sizeof(int32_t));
339 	for (lp = (int32_t *)&freep->next; lp < end; lp++)
340 		*lp = WEIRD_ADDR;
341 
342 	/* and check that the data hasn't been modified. */
343 	if (freshalloc == 0) {
344 		end = (int32_t *)&va[copysize];
345 		for (lp = (int32_t *)va; lp < end; lp++) {
346 			if (*lp == WEIRD_ADDR)
347 				continue;
348 			printf("%s %d of object %p size 0x%lx %s %s"
349 			    " (0x%x != 0x%x)\n",
350 			    "Data modified on freelist: word",
351 			    lp - (int32_t *)va, va, size,
352 			    "previous type", savedtype, *lp, WEIRD_ADDR);
353 			break;
354 		}
355 	}
356 
357 	freep->spare0 = 0;
358 #endif /* DIAGNOSTIC */
359 #ifdef KMEMSTATS
360 	kup = btokup(va);
361 	if (kup->ku_indx != indx)
362 		panic("malloc: wrong bucket");
363 	if (kup->ku_freecnt == 0)
364 		panic("malloc: lost data");
365 	kup->ku_freecnt--;
366 	kbp->kb_totalfree--;
367 	ksp->ks_memuse += 1 << indx;
368 out:
369 	kbp->kb_calls++;
370 	ksp->ks_inuse++;
371 	ksp->ks_calls++;
372 	if (ksp->ks_memuse > ksp->ks_maxused)
373 		ksp->ks_maxused = ksp->ks_memuse;
374 #else
375 out:
376 #endif
377 	splx(s);
378 
379 	if ((flags & M_ZERO) && va != NULL)
380 		memset(va, 0, size);
381 	return (va);
382 }
383 
384 /*
385  * Free a block of memory allocated by malloc.
386  */
387 void
388 free(void *addr, int type)
389 {
390 	struct kmembuckets *kbp;
391 	struct kmemusage *kup;
392 	struct freelist *freep;
393 	long size;
394 	int s;
395 #ifdef DIAGNOSTIC
396 	caddr_t cp;
397 	int32_t *end, *lp;
398 	long alloc, copysize;
399 #endif
400 #ifdef KMEMSTATS
401 	struct kmemstats *ksp = &kmemstats[type];
402 #endif
403 
404 #ifdef MALLOC_DEBUG
405 	if (debug_free(addr, type))
406 		return;
407 #endif
408 
409 #ifdef DIAGNOSTIC
410 	if (addr < (void *)kmembase || addr >= (void *)kmemlimit)
411 		panic("free: non-malloced addr %p type %s", addr,
412 		    memname[type]);
413 #endif
414 
415 	kup = btokup(addr);
416 	size = 1 << kup->ku_indx;
417 	kbp = &bucket[kup->ku_indx];
418 	s = splvm();
419 #ifdef DIAGNOSTIC
420 	/*
421 	 * Check for returns of data that do not point to the
422 	 * beginning of the allocation.
423 	 */
424 	if (size > PAGE_SIZE)
425 		alloc = addrmask[BUCKETINDX(PAGE_SIZE)];
426 	else
427 		alloc = addrmask[kup->ku_indx];
428 	if (((u_long)addr & alloc) != 0)
429 		panic("free: unaligned addr %p, size %ld, type %s, mask %ld",
430 			addr, size, memname[type], alloc);
431 #endif /* DIAGNOSTIC */
432 	if (size > MAXALLOCSAVE) {
433 		uvm_km_free(kmem_map, (vaddr_t)addr, ptoa(kup->ku_pagecnt));
434 #ifdef KMEMSTATS
435 		size = kup->ku_pagecnt << PGSHIFT;
436 		ksp->ks_memuse -= size;
437 		kup->ku_indx = 0;
438 		kup->ku_pagecnt = 0;
439 		if (ksp->ks_memuse + size >= ksp->ks_limit &&
440 		    ksp->ks_memuse < ksp->ks_limit)
441 			wakeup(ksp);
442 		ksp->ks_inuse--;
443 		kbp->kb_total -= 1;
444 #endif
445 		splx(s);
446 		return;
447 	}
448 	freep = (struct freelist *)addr;
449 #ifdef DIAGNOSTIC
450 	/*
451 	 * Check for multiple frees. Use a quick check to see if
452 	 * it looks free before laboriously searching the freelist.
453 	 */
454 	if (freep->spare0 == WEIRD_ADDR) {
455 		for (cp = kbp->kb_next; cp;
456 		    cp = ((struct freelist *)cp)->next) {
457 			if (addr != cp)
458 				continue;
459 			printf("multiply freed item %p\n", addr);
460 			panic("free: duplicated free");
461 		}
462 	}
463 	/*
464 	 * Copy in known text to detect modification after freeing
465 	 * and to make it look free. Also, save the type being freed
466 	 * so we can list likely culprit if modification is detected
467 	 * when the object is reallocated.
468 	 */
469 	copysize = size < MAX_COPY ? size : MAX_COPY;
470 	end = (int32_t *)&((caddr_t)addr)[copysize];
471 	for (lp = (int32_t *)addr; lp < end; lp++)
472 		*lp = WEIRD_ADDR;
473 	freep->type = type;
474 #endif /* DIAGNOSTIC */
475 #ifdef KMEMSTATS
476 	kup->ku_freecnt++;
477 	if (kup->ku_freecnt >= kbp->kb_elmpercl) {
478 		if (kup->ku_freecnt > kbp->kb_elmpercl)
479 			panic("free: multiple frees");
480 		else if (kbp->kb_totalfree > kbp->kb_highwat)
481 			kbp->kb_couldfree++;
482 	}
483 	kbp->kb_totalfree++;
484 	ksp->ks_memuse -= size;
485 	if (ksp->ks_memuse + size >= ksp->ks_limit &&
486 	    ksp->ks_memuse < ksp->ks_limit)
487 		wakeup(ksp);
488 	ksp->ks_inuse--;
489 #endif
490 	if (kbp->kb_next == NULL)
491 		kbp->kb_next = addr;
492 	else
493 		((struct freelist *)kbp->kb_last)->next = addr;
494 	freep->next = NULL;
495 	kbp->kb_last = addr;
496 	splx(s);
497 }
498 
499 /*
500  * Compute the number of pages that kmem_map will map, that is,
501  * the size of the kernel malloc arena.
502  */
503 void
504 kmeminit_nkmempages(void)
505 {
506 	u_int npages;
507 
508 	if (nkmempages != 0) {
509 		/*
510 		 * It's already been set (by us being here before, or
511 		 * by patching or kernel config options), bail out now.
512 		 */
513 		return;
514 	}
515 
516 	/*
517 	 * We can't initialize these variables at compilation time, since
518 	 * the page size may not be known (on sparc GENERIC kernels, for
519 	 * example). But we still want the MD code to be able to provide
520 	 * better values.
521 	 */
522 	if (nkmempages_min == 0)
523 		nkmempages_min = NKMEMPAGES_MIN;
524 	if (nkmempages_max == 0)
525 		nkmempages_max = NKMEMPAGES_MAX;
526 
527 	/*
528 	 * We use the following (simple) formula:
529 	 *
530 	 *	- Starting point is physical memory / 4.
531 	 *
532 	 *	- Clamp it down to nkmempages_max.
533 	 *
534 	 *	- Round it up to nkmempages_min.
535 	 */
536 	npages = physmem / 4;
537 
538 	if (npages > nkmempages_max)
539 		npages = nkmempages_max;
540 
541 	if (npages < nkmempages_min)
542 		npages = nkmempages_min;
543 
544 	nkmempages = npages;
545 }
546 
547 /*
548  * Initialize the kernel memory allocator
549  */
550 void
551 kmeminit(void)
552 {
553 	vaddr_t base, limit;
554 #ifdef KMEMSTATS
555 	long indx;
556 #endif
557 
558 #ifdef DIAGNOSTIC
559 	if (sizeof(struct freelist) > (1 << MINBUCKET))
560 		panic("kmeminit: minbucket too small/struct freelist too big");
561 #endif
562 
563 	/*
564 	 * Compute the number of kmem_map pages, if we have not
565 	 * done so already.
566 	 */
567 	kmeminit_nkmempages();
568 	base = vm_map_min(kernel_map);
569 	kmem_map = uvm_km_suballoc(kernel_map, &base, &limit,
570 	    (vsize_t)(nkmempages * PAGE_SIZE), VM_MAP_INTRSAFE, FALSE,
571 	    &kmem_map_store);
572 	kmembase = (char *)base;
573 	kmemlimit = (char *)limit;
574 	kmemusage = (struct kmemusage *) uvm_km_zalloc(kernel_map,
575 		(vsize_t)(nkmempages * sizeof(struct kmemusage)));
576 #ifdef KMEMSTATS
577 	for (indx = 0; indx < MINBUCKET + 16; indx++) {
578 		if (1 << indx >= PAGE_SIZE)
579 			bucket[indx].kb_elmpercl = 1;
580 		else
581 			bucket[indx].kb_elmpercl = PAGE_SIZE / (1 << indx);
582 		bucket[indx].kb_highwat = 5 * bucket[indx].kb_elmpercl;
583 	}
584 	for (indx = 0; indx < M_LAST; indx++)
585 		kmemstats[indx].ks_limit = nkmempages * PAGE_SIZE * 6 / 10;
586 #endif
587 #ifdef MALLOC_DEBUG
588 	debug_malloc_init();
589 #endif
590 }
591 
592 /*
593  * Return kernel malloc statistics information.
594  */
595 int
596 sysctl_malloc(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp,
597     size_t newlen, struct proc *p)
598 {
599 	struct kmembuckets kb;
600 	int i, siz;
601 
602 	if (namelen != 2 && name[0] != KERN_MALLOC_BUCKETS &&
603 	    name[0] != KERN_MALLOC_KMEMNAMES)
604 		return (ENOTDIR);		/* overloaded */
605 
606 	switch (name[0]) {
607 	case KERN_MALLOC_BUCKETS:
608 		/* Initialize the first time */
609 		if (buckstring_init == 0) {
610 			buckstring_init = 1;
611 			bzero(buckstring, sizeof(buckstring));
612 			for (siz = 0, i = MINBUCKET; i < MINBUCKET + 16; i++) {
613 				snprintf(buckstring + siz,
614 				    sizeof buckstring - siz,
615 				    "%d,", (u_int)(1<<i));
616 				siz += strlen(buckstring + siz);
617 			}
618 			/* Remove trailing comma */
619 			if (siz)
620 				buckstring[siz - 1] = '\0';
621 		}
622 		return (sysctl_rdstring(oldp, oldlenp, newp, buckstring));
623 
624 	case KERN_MALLOC_BUCKET:
625 		bcopy(&bucket[BUCKETINDX(name[1])], &kb, sizeof(kb));
626 		kb.kb_next = kb.kb_last = 0;
627 		return (sysctl_rdstruct(oldp, oldlenp, newp, &kb, sizeof(kb)));
628 	case KERN_MALLOC_KMEMSTATS:
629 #ifdef KMEMSTATS
630 		if ((name[1] < 0) || (name[1] >= M_LAST))
631 			return (EINVAL);
632 		return (sysctl_rdstruct(oldp, oldlenp, newp,
633 		    &kmemstats[name[1]], sizeof(struct kmemstats)));
634 #else
635 		return (EOPNOTSUPP);
636 #endif
637 	case KERN_MALLOC_KMEMNAMES:
638 #if defined(KMEMSTATS) || defined(DIAGNOSTIC) || defined(FFS_SOFTUPDATES)
639 		if (memall == NULL) {
640 			int totlen;
641 
642 			i = rw_enter(&sysctl_kmemlock, RW_WRITE|RW_INTR);
643 			if (i)
644 				return (i);
645 
646 			/* Figure out how large a buffer we need */
647 			for (totlen = 0, i = 0; i < M_LAST; i++) {
648 				if (memname[i])
649 					totlen += strlen(memname[i]);
650 				totlen++;
651 			}
652 			memall = malloc(totlen + M_LAST, M_SYSCTL,
653 			    M_WAITOK|M_ZERO);
654 			for (siz = 0, i = 0; i < M_LAST; i++) {
655 				snprintf(memall + siz,
656 				    totlen + M_LAST - siz,
657 				    "%s,", memname[i] ? memname[i] : "");
658 				siz += strlen(memall + siz);
659 			}
660 			/* Remove trailing comma */
661 			if (siz)
662 				memall[siz - 1] = '\0';
663 
664 			/* Now, convert all spaces to underscores */
665 			for (i = 0; i < totlen; i++)
666 				if (memall[i] == ' ')
667 					memall[i] = '_';
668 			rw_exit_write(&sysctl_kmemlock);
669 		}
670 		return (sysctl_rdstring(oldp, oldlenp, newp, memall));
671 #else
672 		return (EOPNOTSUPP);
673 #endif
674 	default:
675 		return (EOPNOTSUPP);
676 	}
677 	/* NOTREACHED */
678 }
679 
680 /*
681  * Round up a size to how much malloc would actually allocate.
682  */
683 size_t
684 malloc_roundup(size_t sz)
685 {
686 	if (sz > MAXALLOCSAVE)
687 		return round_page(sz);
688 
689 	return (1 << BUCKETINDX(sz));
690 }
691 
692 #if defined(DDB)
693 #include <machine/db_machdep.h>
694 #include <ddb/db_interface.h>
695 #include <ddb/db_output.h>
696 
697 void
698 malloc_printit(int (*pr)(const char *, ...))
699 {
700 #ifdef KMEMSTATS
701 	struct kmemstats *km;
702 	int i;
703 
704 	(*pr)("%15s %5s  %6s  %7s  %6s %9s %8s %8s\n",
705 	    "Type", "InUse", "MemUse", "HighUse", "Limit", "Requests",
706 	    "Type Lim", "Kern Lim");
707 	for (i = 0, km = kmemstats; i < M_LAST; i++, km++) {
708 		if (!km->ks_calls || !memname[i])
709 			continue;
710 
711 		(*pr)("%15s %5ld %6ldK %7ldK %6ldK %9ld %8d %8d\n",
712 		    memname[i], km->ks_inuse, km->ks_memuse / 1024,
713 		    km->ks_maxused / 1024, km->ks_limit / 1024,
714 		    km->ks_calls, km->ks_limblocks, km->ks_mapblocks);
715 	}
716 #else
717 	(*pr)("No KMEMSTATS compiled in\n");
718 #endif
719 }
720 #endif /* DDB */
721