1 /*-
2 * Copyright (c) 1987, 1991, 1993
3 * The Regents of the University of California.
4 * Copyright (c) 2005-2009 Robert N. M. Watson
5 * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net> (mallocarray)
6 * 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 * 4. 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 /*
36 * Kernel malloc(9) implementation -- general purpose kernel memory allocator
37 * based on memory types. Back end is implemented using the UMA(9) zone
38 * allocator. A set of fixed-size buckets are used for smaller allocations,
39 * and a special UMA allocation interface is used for larger allocations.
40 * Callers declare memory types, and statistics are maintained independently
41 * for each memory type. Statistics are maintained per-CPU for performance
42 * reasons. See malloc(9) and comments in malloc.h for a detailed
43 * description.
44 */
45
46 #include <sys/cdefs.h>
47 __FBSDID("$FreeBSD$");
48
49 #include "opt_ddb.h"
50 #include "opt_kdtrace.h"
51 #include "opt_vm.h"
52
53 #include <sys/param.h>
54 #include <sys/systm.h>
55 #include <sys/kdb.h>
56 #include <sys/kernel.h>
57 #include <sys/lock.h>
58 #include <sys/malloc.h>
59 #include <sys/mutex.h>
60 #include <sys/vmmeter.h>
61 #include <sys/proc.h>
62 #include <sys/sbuf.h>
63 #include <sys/sysctl.h>
64 #include <sys/time.h>
65 #include <sys/vmem.h>
66
67 #include <vm/vm.h>
68 #include <vm/pmap.h>
69 #include <vm/vm_pageout.h>
70 #include <vm/vm_param.h>
71 #include <vm/vm_kern.h>
72 #include <vm/vm_extern.h>
73 #include <vm/vm_map.h>
74 #include <vm/vm_page.h>
75 #include <vm/uma.h>
76 #include <vm/uma_int.h>
77 #include <vm/uma_dbg.h>
78
79 #ifdef DEBUG_MEMGUARD
80 #include <vm/memguard.h>
81 #endif
82 #ifdef DEBUG_REDZONE
83 #include <vm/redzone.h>
84 #endif
85
86 #if defined(INVARIANTS) && defined(__i386__)
87 #include <machine/cpu.h>
88 #endif
89
90 #include <ddb/ddb.h>
91
92 #ifdef KDTRACE_HOOKS
93 #include <sys/dtrace_bsd.h>
94
95 dtrace_malloc_probe_func_t dtrace_malloc_probe;
96 #endif
97
98 /*
99 * When realloc() is called, if the new size is sufficiently smaller than
100 * the old size, realloc() will allocate a new, smaller block to avoid
101 * wasting memory. 'Sufficiently smaller' is defined as: newsize <=
102 * oldsize / 2^n, where REALLOC_FRACTION defines the value of 'n'.
103 */
104 #ifndef REALLOC_FRACTION
105 #define REALLOC_FRACTION 1 /* new block if <= half the size */
106 #endif
107
108 /*
109 * Centrally define some common malloc types.
110 */
111 MALLOC_DEFINE(M_CACHE, "cache", "Various Dynamically allocated caches");
112 MALLOC_DEFINE(M_DEVBUF, "devbuf", "device driver memory");
113 MALLOC_DEFINE(M_TEMP, "temp", "misc temporary data buffers");
114
115 MALLOC_DEFINE(M_IP6OPT, "ip6opt", "IPv6 options");
116 MALLOC_DEFINE(M_IP6NDP, "ip6ndp", "IPv6 Neighbor Discovery");
117
118 static struct malloc_type *kmemstatistics;
119 static int kmemcount;
120
121 #define KMEM_ZSHIFT 4
122 #define KMEM_ZBASE 16
123 #define KMEM_ZMASK (KMEM_ZBASE - 1)
124
125 #define KMEM_ZMAX 65536
126 #define KMEM_ZSIZE (KMEM_ZMAX >> KMEM_ZSHIFT)
127 static uint8_t kmemsize[KMEM_ZSIZE + 1];
128
129 #ifndef MALLOC_DEBUG_MAXZONES
130 #define MALLOC_DEBUG_MAXZONES 1
131 #endif
132 static int numzones = MALLOC_DEBUG_MAXZONES;
133
134 /*
135 * Small malloc(9) memory allocations are allocated from a set of UMA buckets
136 * of various sizes.
137 *
138 * XXX: The comment here used to read "These won't be powers of two for
139 * long." It's possible that a significant amount of wasted memory could be
140 * recovered by tuning the sizes of these buckets.
141 */
142 struct {
143 int kz_size;
144 char *kz_name;
145 uma_zone_t kz_zone[MALLOC_DEBUG_MAXZONES];
146 } kmemzones[] = {
147 {16, "16", },
148 {32, "32", },
149 {64, "64", },
150 {128, "128", },
151 {256, "256", },
152 {512, "512", },
153 {1024, "1024", },
154 {2048, "2048", },
155 {4096, "4096", },
156 {8192, "8192", },
157 {16384, "16384", },
158 {32768, "32768", },
159 {65536, "65536", },
160 {0, NULL},
161 };
162
163 /*
164 * Zone to allocate malloc type descriptions from. For ABI reasons, memory
165 * types are described by a data structure passed by the declaring code, but
166 * the malloc(9) implementation has its own data structure describing the
167 * type and statistics. This permits the malloc(9)-internal data structures
168 * to be modified without breaking binary-compiled kernel modules that
169 * declare malloc types.
170 */
171 static uma_zone_t mt_zone;
172
173 u_long vm_kmem_size;
174 SYSCTL_ULONG(_vm, OID_AUTO, kmem_size, CTLFLAG_RDTUN, &vm_kmem_size, 0,
175 "Size of kernel memory");
176
177 static u_long kmem_zmax = KMEM_ZMAX;
178 SYSCTL_ULONG(_vm, OID_AUTO, kmem_zmax, CTLFLAG_RDTUN, &kmem_zmax, 0,
179 "Maximum allocation size that malloc(9) would use UMA as backend");
180
181 static u_long vm_kmem_size_min;
182 SYSCTL_ULONG(_vm, OID_AUTO, kmem_size_min, CTLFLAG_RDTUN, &vm_kmem_size_min, 0,
183 "Minimum size of kernel memory");
184
185 static u_long vm_kmem_size_max;
186 SYSCTL_ULONG(_vm, OID_AUTO, kmem_size_max, CTLFLAG_RDTUN, &vm_kmem_size_max, 0,
187 "Maximum size of kernel memory");
188
189 static u_int vm_kmem_size_scale;
190 SYSCTL_UINT(_vm, OID_AUTO, kmem_size_scale, CTLFLAG_RDTUN, &vm_kmem_size_scale, 0,
191 "Scale factor for kernel memory size");
192
193 static int sysctl_kmem_map_size(SYSCTL_HANDLER_ARGS);
194 SYSCTL_PROC(_vm, OID_AUTO, kmem_map_size,
195 CTLFLAG_RD | CTLTYPE_ULONG | CTLFLAG_MPSAFE, NULL, 0,
196 sysctl_kmem_map_size, "LU", "Current kmem allocation size");
197
198 static int sysctl_kmem_map_free(SYSCTL_HANDLER_ARGS);
199 SYSCTL_PROC(_vm, OID_AUTO, kmem_map_free,
200 CTLFLAG_RD | CTLTYPE_ULONG | CTLFLAG_MPSAFE, NULL, 0,
201 sysctl_kmem_map_free, "LU", "Free space in kmem");
202
203 /*
204 * The malloc_mtx protects the kmemstatistics linked list.
205 */
206 struct mtx malloc_mtx;
207
208 #ifdef MALLOC_PROFILE
209 uint64_t krequests[KMEM_ZSIZE + 1];
210
211 static int sysctl_kern_mprof(SYSCTL_HANDLER_ARGS);
212 #endif
213
214 static int sysctl_kern_malloc_stats(SYSCTL_HANDLER_ARGS);
215
216 /*
217 * time_uptime of the last malloc(9) failure (induced or real).
218 */
219 static time_t t_malloc_fail;
220
221 #if defined(MALLOC_MAKE_FAILURES) || (MALLOC_DEBUG_MAXZONES > 1)
222 static SYSCTL_NODE(_debug, OID_AUTO, malloc, CTLFLAG_RD, 0,
223 "Kernel malloc debugging options");
224 #endif
225
226 /*
227 * malloc(9) fault injection -- cause malloc failures every (n) mallocs when
228 * the caller specifies M_NOWAIT. If set to 0, no failures are caused.
229 */
230 #ifdef MALLOC_MAKE_FAILURES
231 static int malloc_failure_rate;
232 static int malloc_nowait_count;
233 static int malloc_failure_count;
234 SYSCTL_INT(_debug_malloc, OID_AUTO, failure_rate, CTLFLAG_RW,
235 &malloc_failure_rate, 0, "Every (n) mallocs with M_NOWAIT will fail");
236 TUNABLE_INT("debug.malloc.failure_rate", &malloc_failure_rate);
237 SYSCTL_INT(_debug_malloc, OID_AUTO, failure_count, CTLFLAG_RD,
238 &malloc_failure_count, 0, "Number of imposed M_NOWAIT malloc failures");
239 #endif
240
241 static int
242 sysctl_kmem_map_size(SYSCTL_HANDLER_ARGS)
243 {
244 u_long size;
245
246 size = vmem_size(kmem_arena, VMEM_ALLOC);
247 return (sysctl_handle_long(oidp, &size, 0, req));
248 }
249
250 static int
251 sysctl_kmem_map_free(SYSCTL_HANDLER_ARGS)
252 {
253 u_long size;
254
255 size = vmem_size(kmem_arena, VMEM_FREE);
256 return (sysctl_handle_long(oidp, &size, 0, req));
257 }
258
259 /*
260 * malloc(9) uma zone separation -- sub-page buffer overruns in one
261 * malloc type will affect only a subset of other malloc types.
262 */
263 #if MALLOC_DEBUG_MAXZONES > 1
264 static void
265 tunable_set_numzones(void)
266 {
267
268 TUNABLE_INT_FETCH("debug.malloc.numzones",
269 &numzones);
270
271 /* Sanity check the number of malloc uma zones. */
272 if (numzones <= 0)
273 numzones = 1;
274 if (numzones > MALLOC_DEBUG_MAXZONES)
275 numzones = MALLOC_DEBUG_MAXZONES;
276 }
277 SYSINIT(numzones, SI_SUB_TUNABLES, SI_ORDER_ANY, tunable_set_numzones, NULL);
278 SYSCTL_INT(_debug_malloc, OID_AUTO, numzones, CTLFLAG_RDTUN,
279 &numzones, 0, "Number of malloc uma subzones");
280
281 /*
282 * Any number that changes regularly is an okay choice for the
283 * offset. Build numbers are pretty good of you have them.
284 */
285 static u_int zone_offset = __FreeBSD_version;
286 TUNABLE_INT("debug.malloc.zone_offset", &zone_offset);
287 SYSCTL_UINT(_debug_malloc, OID_AUTO, zone_offset, CTLFLAG_RDTUN,
288 &zone_offset, 0, "Separate malloc types by examining the "
289 "Nth character in the malloc type short description.");
290
291 static u_int
292 mtp_get_subzone(const char *desc)
293 {
294 size_t len;
295 u_int val;
296
297 if (desc == NULL || (len = strlen(desc)) == 0)
298 return (0);
299 val = desc[zone_offset % len];
300 return (val % numzones);
301 }
302 #elif MALLOC_DEBUG_MAXZONES == 0
303 #error "MALLOC_DEBUG_MAXZONES must be positive."
304 #else
305 static inline u_int
306 mtp_get_subzone(const char *desc)
307 {
308
309 return (0);
310 }
311 #endif /* MALLOC_DEBUG_MAXZONES > 1 */
312
313 int
314 malloc_last_fail(void)
315 {
316
317 return (time_uptime - t_malloc_fail);
318 }
319
320 /*
321 * An allocation has succeeded -- update malloc type statistics for the
322 * amount of bucket size. Occurs within a critical section so that the
323 * thread isn't preempted and doesn't migrate while updating per-PCU
324 * statistics.
325 */
326 static void
327 malloc_type_zone_allocated(struct malloc_type *mtp, unsigned long size,
328 int zindx)
329 {
330 struct malloc_type_internal *mtip;
331 struct malloc_type_stats *mtsp;
332
333 critical_enter();
334 mtip = mtp->ks_handle;
335 mtsp = &mtip->mti_stats[curcpu];
336 if (size > 0) {
337 mtsp->mts_memalloced += size;
338 mtsp->mts_numallocs++;
339 }
340 if (zindx != -1)
341 mtsp->mts_size |= 1 << zindx;
342
343 #ifdef KDTRACE_HOOKS
344 if (dtrace_malloc_probe != NULL) {
345 uint32_t probe_id = mtip->mti_probes[DTMALLOC_PROBE_MALLOC];
346 if (probe_id != 0)
347 (dtrace_malloc_probe)(probe_id,
348 (uintptr_t) mtp, (uintptr_t) mtip,
349 (uintptr_t) mtsp, size, zindx);
350 }
351 #endif
352
353 critical_exit();
354 }
355
356 void
357 malloc_type_allocated(struct malloc_type *mtp, unsigned long size)
358 {
359
360 if (size > 0)
361 malloc_type_zone_allocated(mtp, size, -1);
362 }
363
364 /*
365 * A free operation has occurred -- update malloc type statistics for the
366 * amount of the bucket size. Occurs within a critical section so that the
367 * thread isn't preempted and doesn't migrate while updating per-CPU
368 * statistics.
369 */
370 void
371 malloc_type_freed(struct malloc_type *mtp, unsigned long size)
372 {
373 struct malloc_type_internal *mtip;
374 struct malloc_type_stats *mtsp;
375
376 critical_enter();
377 mtip = mtp->ks_handle;
378 mtsp = &mtip->mti_stats[curcpu];
379 mtsp->mts_memfreed += size;
380 mtsp->mts_numfrees++;
381
382 #ifdef KDTRACE_HOOKS
383 if (dtrace_malloc_probe != NULL) {
384 uint32_t probe_id = mtip->mti_probes[DTMALLOC_PROBE_FREE];
385 if (probe_id != 0)
386 (dtrace_malloc_probe)(probe_id,
387 (uintptr_t) mtp, (uintptr_t) mtip,
388 (uintptr_t) mtsp, size, 0);
389 }
390 #endif
391
392 critical_exit();
393 }
394
395 /*
396 * contigmalloc:
397 *
398 * Allocate a block of physically contiguous memory.
399 *
400 * If M_NOWAIT is set, this routine will not block and return NULL if
401 * the allocation fails.
402 */
403 void *
404 contigmalloc(unsigned long size, struct malloc_type *type, int flags,
405 vm_paddr_t low, vm_paddr_t high, unsigned long alignment,
406 vm_paddr_t boundary)
407 {
408 void *ret;
409
410 ret = (void *)kmem_alloc_contig(kernel_arena, size, flags, low, high,
411 alignment, boundary, VM_MEMATTR_DEFAULT);
412 if (ret != NULL)
413 malloc_type_allocated(type, round_page(size));
414 return (ret);
415 }
416
417 /*
418 * contigfree:
419 *
420 * Free a block of memory allocated by contigmalloc.
421 *
422 * This routine may not block.
423 */
424 void
425 contigfree(void *addr, unsigned long size, struct malloc_type *type)
426 {
427
428 kmem_free(kernel_arena, (vm_offset_t)addr, size);
429 malloc_type_freed(type, round_page(size));
430 }
431
432 /*
433 * malloc:
434 *
435 * Allocate a block of memory.
436 *
437 * If M_NOWAIT is set, this routine will not block and return NULL if
438 * the allocation fails.
439 */
440 void *
441 malloc(unsigned long size, struct malloc_type *mtp, int flags)
442 {
443 int indx;
444 struct malloc_type_internal *mtip;
445 caddr_t va;
446 uma_zone_t zone;
447 #if defined(DIAGNOSTIC) || defined(DEBUG_REDZONE)
448 unsigned long osize = size;
449 #endif
450
451 #ifdef INVARIANTS
452 KASSERT(mtp->ks_magic == M_MAGIC, ("malloc: bad malloc type magic"));
453 /*
454 * Check that exactly one of M_WAITOK or M_NOWAIT is specified.
455 */
456 indx = flags & (M_WAITOK | M_NOWAIT);
457 if (indx != M_NOWAIT && indx != M_WAITOK) {
458 static struct timeval lasterr;
459 static int curerr, once;
460 if (once == 0 && ppsratecheck(&lasterr, &curerr, 1)) {
461 printf("Bad malloc flags: %x\n", indx);
462 kdb_backtrace();
463 flags |= M_WAITOK;
464 once++;
465 }
466 }
467 #endif
468 #ifdef MALLOC_MAKE_FAILURES
469 if ((flags & M_NOWAIT) && (malloc_failure_rate != 0)) {
470 atomic_add_int(&malloc_nowait_count, 1);
471 if ((malloc_nowait_count % malloc_failure_rate) == 0) {
472 atomic_add_int(&malloc_failure_count, 1);
473 t_malloc_fail = time_uptime;
474 return (NULL);
475 }
476 }
477 #endif
478 if (flags & M_WAITOK)
479 KASSERT(curthread->td_intr_nesting_level == 0,
480 ("malloc(M_WAITOK) in interrupt context"));
481
482 #ifdef DEBUG_MEMGUARD
483 if (memguard_cmp_mtp(mtp, size)) {
484 va = memguard_alloc(size, flags);
485 if (va != NULL)
486 return (va);
487 /* This is unfortunate but should not be fatal. */
488 }
489 #endif
490
491 #ifdef DEBUG_REDZONE
492 size = redzone_size_ntor(size);
493 #endif
494
495 if (size <= kmem_zmax) {
496 mtip = mtp->ks_handle;
497 if (size & KMEM_ZMASK)
498 size = (size & ~KMEM_ZMASK) + KMEM_ZBASE;
499 indx = kmemsize[size >> KMEM_ZSHIFT];
500 KASSERT(mtip->mti_zone < numzones,
501 ("mti_zone %u out of range %d",
502 mtip->mti_zone, numzones));
503 zone = kmemzones[indx].kz_zone[mtip->mti_zone];
504 #ifdef MALLOC_PROFILE
505 krequests[size >> KMEM_ZSHIFT]++;
506 #endif
507 va = uma_zalloc(zone, flags);
508 if (va != NULL)
509 size = zone->uz_size;
510 malloc_type_zone_allocated(mtp, va == NULL ? 0 : size, indx);
511 } else {
512 size = roundup(size, PAGE_SIZE);
513 zone = NULL;
514 va = uma_large_malloc(size, flags);
515 malloc_type_allocated(mtp, va == NULL ? 0 : size);
516 }
517 if (flags & M_WAITOK)
518 KASSERT(va != NULL, ("malloc(M_WAITOK) returned NULL"));
519 else if (va == NULL)
520 t_malloc_fail = time_uptime;
521 #ifdef DIAGNOSTIC
522 if (va != NULL && !(flags & M_ZERO)) {
523 memset(va, 0x70, osize);
524 }
525 #endif
526 #ifdef DEBUG_REDZONE
527 if (va != NULL)
528 va = redzone_setup(va, osize);
529 #endif
530 return ((void *) va);
531 }
532
533 void *
534 mallocarray(size_t nmemb, size_t size, struct malloc_type *type, int flags)
535 {
536
537 if (WOULD_OVERFLOW(nmemb, size))
538 panic("mallocarray: %zu * %zu overflowed", nmemb, size);
539
540 return (malloc(size * nmemb, type, flags));
541 }
542
543 /*
544 * free:
545 *
546 * Free a block of memory allocated by malloc.
547 *
548 * This routine may not block.
549 */
550 void
551 free(void *addr, struct malloc_type *mtp)
552 {
553 uma_slab_t slab;
554 u_long size;
555
556 KASSERT(mtp->ks_magic == M_MAGIC, ("free: bad malloc type magic"));
557
558 /* free(NULL, ...) does nothing */
559 if (addr == NULL)
560 return;
561
562 #ifdef DEBUG_MEMGUARD
563 if (is_memguard_addr(addr)) {
564 memguard_free(addr);
565 return;
566 }
567 #endif
568
569 #ifdef DEBUG_REDZONE
570 redzone_check(addr);
571 addr = redzone_addr_ntor(addr);
572 #endif
573
574 slab = vtoslab((vm_offset_t)addr & (~UMA_SLAB_MASK));
575
576 if (slab == NULL)
577 panic("free: address %p(%p) has not been allocated.\n",
578 addr, (void *)((u_long)addr & (~UMA_SLAB_MASK)));
579
580 if (!(slab->us_flags & UMA_SLAB_MALLOC)) {
581 #ifdef INVARIANTS
582 struct malloc_type **mtpp = addr;
583 #endif
584 size = slab->us_keg->uk_size;
585 #ifdef INVARIANTS
586 /*
587 * Cache a pointer to the malloc_type that most recently freed
588 * this memory here. This way we know who is most likely to
589 * have stepped on it later.
590 *
591 * This code assumes that size is a multiple of 8 bytes for
592 * 64 bit machines
593 */
594 mtpp = (struct malloc_type **)
595 ((unsigned long)mtpp & ~UMA_ALIGN_PTR);
596 mtpp += (size - sizeof(struct malloc_type *)) /
597 sizeof(struct malloc_type *);
598 *mtpp = mtp;
599 #endif
600 uma_zfree_arg(LIST_FIRST(&slab->us_keg->uk_zones), addr, slab);
601 } else {
602 size = slab->us_size;
603 uma_large_free(slab);
604 }
605 malloc_type_freed(mtp, size);
606 }
607
608 /*
609 * realloc: change the size of a memory block
610 */
611 void *
612 realloc(void *addr, unsigned long size, struct malloc_type *mtp, int flags)
613 {
614 uma_slab_t slab;
615 unsigned long alloc;
616 void *newaddr;
617
618 KASSERT(mtp->ks_magic == M_MAGIC,
619 ("realloc: bad malloc type magic"));
620
621 /* realloc(NULL, ...) is equivalent to malloc(...) */
622 if (addr == NULL)
623 return (malloc(size, mtp, flags));
624
625 /*
626 * XXX: Should report free of old memory and alloc of new memory to
627 * per-CPU stats.
628 */
629
630 #ifdef DEBUG_MEMGUARD
631 if (is_memguard_addr(addr))
632 return (memguard_realloc(addr, size, mtp, flags));
633 #endif
634
635 #ifdef DEBUG_REDZONE
636 slab = NULL;
637 alloc = redzone_get_size(addr);
638 #else
639 slab = vtoslab((vm_offset_t)addr & ~(UMA_SLAB_MASK));
640
641 /* Sanity check */
642 KASSERT(slab != NULL,
643 ("realloc: address %p out of range", (void *)addr));
644
645 /* Get the size of the original block */
646 if (!(slab->us_flags & UMA_SLAB_MALLOC))
647 alloc = slab->us_keg->uk_size;
648 else
649 alloc = slab->us_size;
650
651 /* Reuse the original block if appropriate */
652 if (size <= alloc
653 && (size > (alloc >> REALLOC_FRACTION) || alloc == MINALLOCSIZE))
654 return (addr);
655 #endif /* !DEBUG_REDZONE */
656
657 /* Allocate a new, bigger (or smaller) block */
658 if ((newaddr = malloc(size, mtp, flags)) == NULL)
659 return (NULL);
660
661 /* Copy over original contents */
662 bcopy(addr, newaddr, min(size, alloc));
663 free(addr, mtp);
664 return (newaddr);
665 }
666
667 /*
668 * reallocf: same as realloc() but free memory on failure.
669 */
670 void *
671 reallocf(void *addr, unsigned long size, struct malloc_type *mtp, int flags)
672 {
673 void *mem;
674
675 if ((mem = realloc(addr, size, mtp, flags)) == NULL)
676 free(addr, mtp);
677 return (mem);
678 }
679
680 /*
681 * Wake the uma reclamation pagedaemon thread when we exhaust KVA. It
682 * will call the lowmem handler and uma_reclaim() callbacks in a
683 * context that is safe.
684 */
685 static void
686 kmem_reclaim(vmem_t *vm, int flags)
687 {
688
689 uma_reclaim_wakeup();
690 pagedaemon_wakeup();
691 }
692
693 CTASSERT(VM_KMEM_SIZE_SCALE >= 1);
694
695 /*
696 * Initialize the kernel memory (kmem) arena.
697 */
698 void
699 kmeminit(void)
700 {
701 u_long mem_size, tmp;
702
703 /*
704 * Calculate the amount of kernel virtual address (KVA) space that is
705 * preallocated to the kmem arena. In order to support a wide range
706 * of machines, it is a function of the physical memory size,
707 * specifically,
708 *
709 * min(max(physical memory size / VM_KMEM_SIZE_SCALE,
710 * VM_KMEM_SIZE_MIN), VM_KMEM_SIZE_MAX)
711 *
712 * Every architecture must define an integral value for
713 * VM_KMEM_SIZE_SCALE. However, the definitions of VM_KMEM_SIZE_MIN
714 * and VM_KMEM_SIZE_MAX, which represent respectively the floor and
715 * ceiling on this preallocation, are optional. Typically,
716 * VM_KMEM_SIZE_MAX is itself a function of the available KVA space on
717 * a given architecture.
718 */
719 mem_size = cnt.v_page_count;
720
721 vm_kmem_size_scale = VM_KMEM_SIZE_SCALE;
722 TUNABLE_INT_FETCH("vm.kmem_size_scale", &vm_kmem_size_scale);
723 if (vm_kmem_size_scale < 1)
724 vm_kmem_size_scale = VM_KMEM_SIZE_SCALE;
725
726 vm_kmem_size = (mem_size / vm_kmem_size_scale) * PAGE_SIZE;
727
728 #if defined(VM_KMEM_SIZE_MIN)
729 vm_kmem_size_min = VM_KMEM_SIZE_MIN;
730 #endif
731 TUNABLE_ULONG_FETCH("vm.kmem_size_min", &vm_kmem_size_min);
732 if (vm_kmem_size_min > 0 && vm_kmem_size < vm_kmem_size_min)
733 vm_kmem_size = vm_kmem_size_min;
734
735 #if defined(VM_KMEM_SIZE_MAX)
736 vm_kmem_size_max = VM_KMEM_SIZE_MAX;
737 #endif
738 TUNABLE_ULONG_FETCH("vm.kmem_size_max", &vm_kmem_size_max);
739 if (vm_kmem_size_max > 0 && vm_kmem_size >= vm_kmem_size_max)
740 vm_kmem_size = vm_kmem_size_max;
741
742 /*
743 * Alternatively, the amount of KVA space that is preallocated to the
744 * kmem arena can be set statically at compile-time or manually
745 * through the kernel environment. However, it is still limited to
746 * twice the physical memory size, which has been sufficient to handle
747 * the most severe cases of external fragmentation in the kmem arena.
748 */
749 #if defined(VM_KMEM_SIZE)
750 vm_kmem_size = VM_KMEM_SIZE;
751 #endif
752 TUNABLE_ULONG_FETCH("vm.kmem_size", &vm_kmem_size);
753 if (vm_kmem_size / 2 / PAGE_SIZE > mem_size)
754 vm_kmem_size = 2 * mem_size * PAGE_SIZE;
755
756 vm_kmem_size = round_page(vm_kmem_size);
757 #ifdef DEBUG_MEMGUARD
758 tmp = memguard_fudge(vm_kmem_size, kernel_map);
759 #else
760 tmp = vm_kmem_size;
761 #endif
762 vmem_init(kmem_arena, "kmem arena", kva_alloc(tmp), tmp, PAGE_SIZE,
763 0, 0);
764 vmem_set_reclaim(kmem_arena, kmem_reclaim);
765
766 #ifdef DEBUG_MEMGUARD
767 /*
768 * Initialize MemGuard if support compiled in. MemGuard is a
769 * replacement allocator used for detecting tamper-after-free
770 * scenarios as they occur. It is only used for debugging.
771 */
772 memguard_init(kmem_arena);
773 #endif
774 }
775
776 /*
777 * Initialize the kernel memory allocator
778 */
779 /* ARGSUSED*/
780 static void
781 mallocinit(void *dummy)
782 {
783 int i;
784 uint8_t indx;
785
786 mtx_init(&malloc_mtx, "malloc", NULL, MTX_DEF);
787
788 kmeminit();
789
790 uma_startup2();
791
792 if (kmem_zmax < PAGE_SIZE || kmem_zmax > KMEM_ZMAX)
793 kmem_zmax = KMEM_ZMAX;
794
795 mt_zone = uma_zcreate("mt_zone", sizeof(struct malloc_type_internal),
796 #ifdef INVARIANTS
797 mtrash_ctor, mtrash_dtor, mtrash_init, mtrash_fini,
798 #else
799 NULL, NULL, NULL, NULL,
800 #endif
801 UMA_ALIGN_PTR, UMA_ZONE_MALLOC);
802 for (i = 0, indx = 0; kmemzones[indx].kz_size != 0; indx++) {
803 int size = kmemzones[indx].kz_size;
804 char *name = kmemzones[indx].kz_name;
805 int subzone;
806
807 for (subzone = 0; subzone < numzones; subzone++) {
808 kmemzones[indx].kz_zone[subzone] =
809 uma_zcreate(name, size,
810 #ifdef INVARIANTS
811 mtrash_ctor, mtrash_dtor, mtrash_init, mtrash_fini,
812 #else
813 NULL, NULL, NULL, NULL,
814 #endif
815 UMA_ALIGN_PTR, UMA_ZONE_MALLOC);
816 }
817 for (;i <= size; i+= KMEM_ZBASE)
818 kmemsize[i >> KMEM_ZSHIFT] = indx;
819
820 }
821 }
822 SYSINIT(kmem, SI_SUB_KMEM, SI_ORDER_FIRST, mallocinit, NULL);
823
824 void
825 malloc_init(void *data)
826 {
827 struct malloc_type_internal *mtip;
828 struct malloc_type *mtp;
829
830 KASSERT(cnt.v_page_count != 0, ("malloc_register before vm_init"));
831
832 mtp = data;
833 if (mtp->ks_magic != M_MAGIC)
834 panic("malloc_init: bad malloc type magic");
835
836 mtip = uma_zalloc(mt_zone, M_WAITOK | M_ZERO);
837 mtp->ks_handle = mtip;
838 mtip->mti_zone = mtp_get_subzone(mtp->ks_shortdesc);
839
840 mtx_lock(&malloc_mtx);
841 mtp->ks_next = kmemstatistics;
842 kmemstatistics = mtp;
843 kmemcount++;
844 mtx_unlock(&malloc_mtx);
845 }
846
847 void
848 malloc_uninit(void *data)
849 {
850 struct malloc_type_internal *mtip;
851 struct malloc_type_stats *mtsp;
852 struct malloc_type *mtp, *temp;
853 uma_slab_t slab;
854 long temp_allocs, temp_bytes;
855 int i;
856
857 mtp = data;
858 KASSERT(mtp->ks_magic == M_MAGIC,
859 ("malloc_uninit: bad malloc type magic"));
860 KASSERT(mtp->ks_handle != NULL, ("malloc_deregister: cookie NULL"));
861
862 mtx_lock(&malloc_mtx);
863 mtip = mtp->ks_handle;
864 mtp->ks_handle = NULL;
865 if (mtp != kmemstatistics) {
866 for (temp = kmemstatistics; temp != NULL;
867 temp = temp->ks_next) {
868 if (temp->ks_next == mtp) {
869 temp->ks_next = mtp->ks_next;
870 break;
871 }
872 }
873 KASSERT(temp,
874 ("malloc_uninit: type '%s' not found", mtp->ks_shortdesc));
875 } else
876 kmemstatistics = mtp->ks_next;
877 kmemcount--;
878 mtx_unlock(&malloc_mtx);
879
880 /*
881 * Look for memory leaks.
882 */
883 temp_allocs = temp_bytes = 0;
884 for (i = 0; i < MAXCPU; i++) {
885 mtsp = &mtip->mti_stats[i];
886 temp_allocs += mtsp->mts_numallocs;
887 temp_allocs -= mtsp->mts_numfrees;
888 temp_bytes += mtsp->mts_memalloced;
889 temp_bytes -= mtsp->mts_memfreed;
890 }
891 if (temp_allocs > 0 || temp_bytes > 0) {
892 printf("Warning: memory type %s leaked memory on destroy "
893 "(%ld allocations, %ld bytes leaked).\n", mtp->ks_shortdesc,
894 temp_allocs, temp_bytes);
895 }
896
897 slab = vtoslab((vm_offset_t) mtip & (~UMA_SLAB_MASK));
898 uma_zfree_arg(mt_zone, mtip, slab);
899 }
900
901 struct malloc_type *
902 malloc_desc2type(const char *desc)
903 {
904 struct malloc_type *mtp;
905
906 mtx_assert(&malloc_mtx, MA_OWNED);
907 for (mtp = kmemstatistics; mtp != NULL; mtp = mtp->ks_next) {
908 if (strcmp(mtp->ks_shortdesc, desc) == 0)
909 return (mtp);
910 }
911 return (NULL);
912 }
913
914 static int
915 sysctl_kern_malloc_stats(SYSCTL_HANDLER_ARGS)
916 {
917 struct malloc_type_stream_header mtsh;
918 struct malloc_type_internal *mtip;
919 struct malloc_type_header mth;
920 struct malloc_type *mtp;
921 int error, i;
922 struct sbuf sbuf;
923
924 error = sysctl_wire_old_buffer(req, 0);
925 if (error != 0)
926 return (error);
927 sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
928 mtx_lock(&malloc_mtx);
929
930 /*
931 * Insert stream header.
932 */
933 bzero(&mtsh, sizeof(mtsh));
934 mtsh.mtsh_version = MALLOC_TYPE_STREAM_VERSION;
935 mtsh.mtsh_maxcpus = MAXCPU;
936 mtsh.mtsh_count = kmemcount;
937 (void)sbuf_bcat(&sbuf, &mtsh, sizeof(mtsh));
938
939 /*
940 * Insert alternating sequence of type headers and type statistics.
941 */
942 for (mtp = kmemstatistics; mtp != NULL; mtp = mtp->ks_next) {
943 mtip = (struct malloc_type_internal *)mtp->ks_handle;
944
945 /*
946 * Insert type header.
947 */
948 bzero(&mth, sizeof(mth));
949 strlcpy(mth.mth_name, mtp->ks_shortdesc, MALLOC_MAX_NAME);
950 (void)sbuf_bcat(&sbuf, &mth, sizeof(mth));
951
952 /*
953 * Insert type statistics for each CPU.
954 */
955 for (i = 0; i < MAXCPU; i++) {
956 (void)sbuf_bcat(&sbuf, &mtip->mti_stats[i],
957 sizeof(mtip->mti_stats[i]));
958 }
959 }
960 mtx_unlock(&malloc_mtx);
961 error = sbuf_finish(&sbuf);
962 sbuf_delete(&sbuf);
963 return (error);
964 }
965
966 SYSCTL_PROC(_kern, OID_AUTO, malloc_stats, CTLFLAG_RD|CTLTYPE_STRUCT,
967 0, 0, sysctl_kern_malloc_stats, "s,malloc_type_ustats",
968 "Return malloc types");
969
970 SYSCTL_INT(_kern, OID_AUTO, malloc_count, CTLFLAG_RD, &kmemcount, 0,
971 "Count of kernel malloc types");
972
973 void
974 malloc_type_list(malloc_type_list_func_t *func, void *arg)
975 {
976 struct malloc_type *mtp, **bufmtp;
977 int count, i;
978 size_t buflen;
979
980 mtx_lock(&malloc_mtx);
981 restart:
982 mtx_assert(&malloc_mtx, MA_OWNED);
983 count = kmemcount;
984 mtx_unlock(&malloc_mtx);
985
986 buflen = sizeof(struct malloc_type *) * count;
987 bufmtp = malloc(buflen, M_TEMP, M_WAITOK);
988
989 mtx_lock(&malloc_mtx);
990
991 if (count < kmemcount) {
992 free(bufmtp, M_TEMP);
993 goto restart;
994 }
995
996 for (mtp = kmemstatistics, i = 0; mtp != NULL; mtp = mtp->ks_next, i++)
997 bufmtp[i] = mtp;
998
999 mtx_unlock(&malloc_mtx);
1000
1001 for (i = 0; i < count; i++)
1002 (func)(bufmtp[i], arg);
1003
1004 free(bufmtp, M_TEMP);
1005 }
1006
1007 #ifdef DDB
1008 DB_SHOW_COMMAND(malloc, db_show_malloc)
1009 {
1010 struct malloc_type_internal *mtip;
1011 struct malloc_type *mtp;
1012 uint64_t allocs, frees;
1013 uint64_t alloced, freed;
1014 int i;
1015
1016 db_printf("%18s %12s %12s %12s\n", "Type", "InUse", "MemUse",
1017 "Requests");
1018 for (mtp = kmemstatistics; mtp != NULL; mtp = mtp->ks_next) {
1019 mtip = (struct malloc_type_internal *)mtp->ks_handle;
1020 allocs = 0;
1021 frees = 0;
1022 alloced = 0;
1023 freed = 0;
1024 for (i = 0; i < MAXCPU; i++) {
1025 allocs += mtip->mti_stats[i].mts_numallocs;
1026 frees += mtip->mti_stats[i].mts_numfrees;
1027 alloced += mtip->mti_stats[i].mts_memalloced;
1028 freed += mtip->mti_stats[i].mts_memfreed;
1029 }
1030 db_printf("%18s %12ju %12juK %12ju\n",
1031 mtp->ks_shortdesc, allocs - frees,
1032 (alloced - freed + 1023) / 1024, allocs);
1033 if (db_pager_quit)
1034 break;
1035 }
1036 }
1037
1038 #if MALLOC_DEBUG_MAXZONES > 1
1039 DB_SHOW_COMMAND(multizone_matches, db_show_multizone_matches)
1040 {
1041 struct malloc_type_internal *mtip;
1042 struct malloc_type *mtp;
1043 u_int subzone;
1044
1045 if (!have_addr) {
1046 db_printf("Usage: show multizone_matches <malloc type/addr>\n");
1047 return;
1048 }
1049 mtp = (void *)addr;
1050 if (mtp->ks_magic != M_MAGIC) {
1051 db_printf("Magic %lx does not match expected %x\n",
1052 mtp->ks_magic, M_MAGIC);
1053 return;
1054 }
1055
1056 mtip = mtp->ks_handle;
1057 subzone = mtip->mti_zone;
1058
1059 for (mtp = kmemstatistics; mtp != NULL; mtp = mtp->ks_next) {
1060 mtip = mtp->ks_handle;
1061 if (mtip->mti_zone != subzone)
1062 continue;
1063 db_printf("%s\n", mtp->ks_shortdesc);
1064 if (db_pager_quit)
1065 break;
1066 }
1067 }
1068 #endif /* MALLOC_DEBUG_MAXZONES > 1 */
1069 #endif /* DDB */
1070
1071 #ifdef MALLOC_PROFILE
1072
1073 static int
1074 sysctl_kern_mprof(SYSCTL_HANDLER_ARGS)
1075 {
1076 struct sbuf sbuf;
1077 uint64_t count;
1078 uint64_t waste;
1079 uint64_t mem;
1080 int error;
1081 int rsize;
1082 int size;
1083 int i;
1084
1085 waste = 0;
1086 mem = 0;
1087
1088 error = sysctl_wire_old_buffer(req, 0);
1089 if (error != 0)
1090 return (error);
1091 sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
1092 sbuf_printf(&sbuf,
1093 "\n Size Requests Real Size\n");
1094 for (i = 0; i < KMEM_ZSIZE; i++) {
1095 size = i << KMEM_ZSHIFT;
1096 rsize = kmemzones[kmemsize[i]].kz_size;
1097 count = (long long unsigned)krequests[i];
1098
1099 sbuf_printf(&sbuf, "%6d%28llu%11d\n", size,
1100 (unsigned long long)count, rsize);
1101
1102 if ((rsize * count) > (size * count))
1103 waste += (rsize * count) - (size * count);
1104 mem += (rsize * count);
1105 }
1106 sbuf_printf(&sbuf,
1107 "\nTotal memory used:\t%30llu\nTotal Memory wasted:\t%30llu\n",
1108 (unsigned long long)mem, (unsigned long long)waste);
1109 error = sbuf_finish(&sbuf);
1110 sbuf_delete(&sbuf);
1111 return (error);
1112 }
1113
1114 SYSCTL_OID(_kern, OID_AUTO, mprof, CTLTYPE_STRING|CTLFLAG_RD,
1115 NULL, 0, sysctl_kern_mprof, "A", "Malloc Profiling");
1116 #endif /* MALLOC_PROFILE */
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