xref: /freebsd/lib/libmemstat/memstat_malloc.c (revision 8aac90f18aef7c9eea906c3ff9a001ca7b94f375)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2005 Robert N. M. Watson
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/param.h>
30 #include <sys/malloc.h>
31 #include <sys/sysctl.h>
32 
33 #include <err.h>
34 #include <errno.h>
35 #include <kvm.h>
36 #include <nlist.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <string.h>
40 
41 #include "memstat.h"
42 #include "memstat_internal.h"
43 
44 static int memstat_malloc_zone_count;
45 static int memstat_malloc_zone_sizes[32];
46 
47 static int	memstat_malloc_zone_init(void);
48 static int	memstat_malloc_zone_init_kvm(kvm_t *kvm);
49 
50 static struct nlist namelist[] = {
51 #define	X_KMEMSTATISTICS	0
52 	{ .n_name = "_kmemstatistics" },
53 #define	X_KMEMZONES		1
54 	{ .n_name = "_kmemzones" },
55 #define	X_NUMZONES		2
56 	{ .n_name = "_numzones" },
57 #define	X_VM_MALLOC_ZONE_COUNT	3
58 	{ .n_name = "_vm_malloc_zone_count" },
59 #define	X_MP_MAXCPUS		4
60 	{ .n_name = "_mp_maxcpus" },
61 	{ .n_name = "" },
62 };
63 
64 /*
65  * Extract malloc(9) statistics from the running kernel, and store all memory
66  * type information in the passed list.  For each type, check the list for an
67  * existing entry with the right name/allocator -- if present, update that
68  * entry.  Otherwise, add a new entry.  On error, the entire list will be
69  * cleared, as entries will be in an inconsistent state.
70  *
71  * To reduce the level of work for a list that starts empty, we keep around a
72  * hint as to whether it was empty when we began, so we can avoid searching
73  * the list for entries to update.  Updates are O(n^2) due to searching for
74  * each entry before adding it.
75  */
76 int
77 memstat_sysctl_malloc(struct memory_type_list *list, int flags)
78 {
79 	struct malloc_type_stream_header *mtshp;
80 	struct malloc_type_header *mthp;
81 	struct malloc_type_stats *mtsp;
82 	struct memory_type *mtp;
83 	int count, hint_dontsearch, i, j, maxcpus;
84 	char *buffer, *p;
85 	size_t size;
86 
87 	hint_dontsearch = LIST_EMPTY(&list->mtl_list);
88 
89 	/*
90 	 * Query the number of CPUs, number of malloc types so that we can
91 	 * guess an initial buffer size.  We loop until we succeed or really
92 	 * fail.  Note that the value of maxcpus we query using sysctl is not
93 	 * the version we use when processing the real data -- that is read
94 	 * from the header.
95 	 */
96 retry:
97 	size = sizeof(maxcpus);
98 	if (sysctlbyname("kern.smp.maxcpus", &maxcpus, &size, NULL, 0) < 0) {
99 		if (errno == EACCES || errno == EPERM)
100 			list->mtl_error = MEMSTAT_ERROR_PERMISSION;
101 		else
102 			list->mtl_error = MEMSTAT_ERROR_DATAERROR;
103 		return (-1);
104 	}
105 	if (size != sizeof(maxcpus)) {
106 		list->mtl_error = MEMSTAT_ERROR_DATAERROR;
107 		return (-1);
108 	}
109 
110 	size = sizeof(count);
111 	if (sysctlbyname("kern.malloc_count", &count, &size, NULL, 0) < 0) {
112 		if (errno == EACCES || errno == EPERM)
113 			list->mtl_error = MEMSTAT_ERROR_PERMISSION;
114 		else
115 			list->mtl_error = MEMSTAT_ERROR_VERSION;
116 		return (-1);
117 	}
118 	if (size != sizeof(count)) {
119 		list->mtl_error = MEMSTAT_ERROR_DATAERROR;
120 		return (-1);
121 	}
122 
123 	if (memstat_malloc_zone_init() == -1) {
124 		list->mtl_error = MEMSTAT_ERROR_VERSION;
125 		return (-1);
126 	}
127 
128 	size = sizeof(*mthp) + count * (sizeof(*mthp) + sizeof(*mtsp) *
129 	    maxcpus);
130 
131 	buffer = malloc(size);
132 	if (buffer == NULL) {
133 		list->mtl_error = MEMSTAT_ERROR_NOMEMORY;
134 		return (-1);
135 	}
136 
137 	if (sysctlbyname("kern.malloc_stats", buffer, &size, NULL, 0) < 0) {
138 		/*
139 		 * XXXRW: ENOMEM is an ambiguous return, we should bound the
140 		 * number of loops, perhaps.
141 		 */
142 		if (errno == ENOMEM) {
143 			free(buffer);
144 			goto retry;
145 		}
146 		if (errno == EACCES || errno == EPERM)
147 			list->mtl_error = MEMSTAT_ERROR_PERMISSION;
148 		else
149 			list->mtl_error = MEMSTAT_ERROR_VERSION;
150 		free(buffer);
151 		return (-1);
152 	}
153 
154 	if (size == 0) {
155 		free(buffer);
156 		return (0);
157 	}
158 
159 	if (size < sizeof(*mtshp)) {
160 		list->mtl_error = MEMSTAT_ERROR_VERSION;
161 		free(buffer);
162 		return (-1);
163 	}
164 	p = buffer;
165 	mtshp = (struct malloc_type_stream_header *)p;
166 	p += sizeof(*mtshp);
167 
168 	if (mtshp->mtsh_version != MALLOC_TYPE_STREAM_VERSION) {
169 		list->mtl_error = MEMSTAT_ERROR_VERSION;
170 		free(buffer);
171 		return (-1);
172 	}
173 
174 	/*
175 	 * For the remainder of this function, we are quite trusting about
176 	 * the layout of structures and sizes, since we've determined we have
177 	 * a matching version and acceptable CPU count.
178 	 */
179 	maxcpus = mtshp->mtsh_maxcpus;
180 	count = mtshp->mtsh_count;
181 	for (i = 0; i < count; i++) {
182 		mthp = (struct malloc_type_header *)p;
183 		p += sizeof(*mthp);
184 
185 		if (hint_dontsearch == 0) {
186 			mtp = memstat_mtl_find(list, ALLOCATOR_MALLOC,
187 			    mthp->mth_name);
188 		} else
189 			mtp = NULL;
190 		if (mtp == NULL)
191 			mtp = _memstat_mt_allocate(list, ALLOCATOR_MALLOC,
192 			    mthp->mth_name, maxcpus);
193 		if (mtp == NULL) {
194 			_memstat_mtl_empty(list);
195 			free(buffer);
196 			list->mtl_error = MEMSTAT_ERROR_NOMEMORY;
197 			return (-1);
198 		}
199 
200 		/*
201 		 * Reset the statistics on a current node.
202 		 */
203 		_memstat_mt_reset_stats(mtp, maxcpus);
204 
205 		for (j = 0; j < maxcpus; j++) {
206 			mtsp = (struct malloc_type_stats *)p;
207 			p += sizeof(*mtsp);
208 
209 			/*
210 			 * Sumarize raw statistics across CPUs into coalesced
211 			 * statistics.
212 			 */
213 			mtp->mt_memalloced += mtsp->mts_memalloced;
214 			mtp->mt_memfreed += mtsp->mts_memfreed;
215 			mtp->mt_numallocs += mtsp->mts_numallocs;
216 			mtp->mt_numfrees += mtsp->mts_numfrees;
217 			mtp->mt_sizemask |= mtsp->mts_size;
218 
219 			/*
220 			 * Copies of per-CPU statistics.
221 			 */
222 			mtp->mt_percpu_alloc[j].mtp_memalloced =
223 			    mtsp->mts_memalloced;
224 			mtp->mt_percpu_alloc[j].mtp_memfreed =
225 			    mtsp->mts_memfreed;
226 			mtp->mt_percpu_alloc[j].mtp_numallocs =
227 			    mtsp->mts_numallocs;
228 			mtp->mt_percpu_alloc[j].mtp_numfrees =
229 			    mtsp->mts_numfrees;
230 			mtp->mt_percpu_alloc[j].mtp_sizemask =
231 			    mtsp->mts_size;
232 		}
233 
234 		/*
235 		 * Derived cross-CPU statistics.
236 		 */
237 		mtp->mt_bytes = mtp->mt_memalloced - mtp->mt_memfreed;
238 		mtp->mt_count = mtp->mt_numallocs - mtp->mt_numfrees;
239 	}
240 
241 	free(buffer);
242 
243 	return (0);
244 }
245 
246 static int
247 kread(kvm_t *kvm, void *kvm_pointer, void *address, size_t size,
248     size_t offset)
249 {
250 	ssize_t ret;
251 
252 	ret = kvm_read(kvm, (unsigned long)kvm_pointer + offset, address,
253 	    size);
254 	if (ret < 0)
255 		return (MEMSTAT_ERROR_KVM);
256 	if ((size_t)ret != size)
257 		return (MEMSTAT_ERROR_KVM_SHORTREAD);
258 	return (0);
259 }
260 
261 static int
262 kread_string(kvm_t *kvm, const void *kvm_pointer, char *buffer, int buflen)
263 {
264 	ssize_t ret;
265 	int i;
266 
267 	for (i = 0; i < buflen; i++) {
268 		ret = kvm_read(kvm, __DECONST(unsigned long, kvm_pointer) +
269 		    i, &(buffer[i]), sizeof(char));
270 		if (ret < 0)
271 			return (MEMSTAT_ERROR_KVM);
272 		if ((size_t)ret != sizeof(char))
273 			return (MEMSTAT_ERROR_KVM_SHORTREAD);
274 		if (buffer[i] == '\0')
275 			return (0);
276 	}
277 	/* Truncate. */
278 	buffer[i-1] = '\0';
279 	return (0);
280 }
281 
282 static int
283 kread_symbol(kvm_t *kvm, int index, void *address, size_t size,
284     size_t offset)
285 {
286 	ssize_t ret;
287 
288 	ret = kvm_read(kvm, namelist[index].n_value + offset, address, size);
289 	if (ret < 0)
290 		return (MEMSTAT_ERROR_KVM);
291 	if ((size_t)ret != size)
292 		return (MEMSTAT_ERROR_KVM_SHORTREAD);
293 	return (0);
294 }
295 
296 static int
297 kread_zpcpu(kvm_t *kvm, u_long base, void *buf, size_t size, int cpu)
298 {
299 	ssize_t ret;
300 
301 	ret = kvm_read_zpcpu(kvm, base, buf, size, cpu);
302 	if (ret < 0)
303 		return (MEMSTAT_ERROR_KVM);
304 	if ((size_t)ret != size)
305 		return (MEMSTAT_ERROR_KVM_SHORTREAD);
306 	return (0);
307 }
308 
309 int
310 memstat_kvm_malloc(struct memory_type_list *list, void *kvm_handle)
311 {
312 	struct memory_type *mtp;
313 	void *kmemstatistics;
314 	int hint_dontsearch, j, mp_maxcpus, mp_ncpus, ret;
315 	char name[MEMTYPE_MAXNAME];
316 	struct malloc_type_stats mts;
317 	struct malloc_type_internal *mtip;
318 	struct malloc_type type, *typep;
319 	kvm_t *kvm;
320 
321 	kvm = (kvm_t *)kvm_handle;
322 
323 	hint_dontsearch = LIST_EMPTY(&list->mtl_list);
324 
325 	if (kvm_nlist(kvm, namelist) != 0) {
326 		list->mtl_error = MEMSTAT_ERROR_KVM;
327 		return (-1);
328 	}
329 
330 	if (namelist[X_KMEMSTATISTICS].n_type == 0 ||
331 	    namelist[X_KMEMSTATISTICS].n_value == 0) {
332 		list->mtl_error = MEMSTAT_ERROR_KVM_NOSYMBOL;
333 		return (-1);
334 	}
335 
336 	ret = kread_symbol(kvm, X_MP_MAXCPUS, &mp_maxcpus,
337 	    sizeof(mp_maxcpus), 0);
338 	if (ret != 0) {
339 		list->mtl_error = ret;
340 		return (-1);
341 	}
342 
343 	ret = kread_symbol(kvm, X_KMEMSTATISTICS, &kmemstatistics,
344 	    sizeof(kmemstatistics), 0);
345 	if (ret != 0) {
346 		list->mtl_error = ret;
347 		return (-1);
348 	}
349 
350 	ret = memstat_malloc_zone_init_kvm(kvm);
351 	if (ret != 0) {
352 		list->mtl_error = ret;
353 		return (-1);
354 	}
355 
356 	mp_ncpus = kvm_getncpus(kvm);
357 
358 	for (typep = kmemstatistics; typep != NULL; typep = type.ks_next) {
359 		ret = kread(kvm, typep, &type, sizeof(type), 0);
360 		if (ret != 0) {
361 			_memstat_mtl_empty(list);
362 			list->mtl_error = ret;
363 			return (-1);
364 		}
365 		ret = kread_string(kvm, (void *)type.ks_shortdesc, name,
366 		    MEMTYPE_MAXNAME);
367 		if (ret != 0) {
368 			_memstat_mtl_empty(list);
369 			list->mtl_error = ret;
370 			return (-1);
371 		}
372 		if (type.ks_version != M_VERSION) {
373 			warnx("type %s with unsupported version %lu; skipped",
374 			    name, type.ks_version);
375 			continue;
376 		}
377 
378 		/*
379 		 * Since our compile-time value for MAXCPU may differ from the
380 		 * kernel's, we populate our own array.
381 		 */
382 		mtip = &type.ks_mti;
383 
384 		if (hint_dontsearch == 0) {
385 			mtp = memstat_mtl_find(list, ALLOCATOR_MALLOC, name);
386 		} else
387 			mtp = NULL;
388 		if (mtp == NULL)
389 			mtp = _memstat_mt_allocate(list, ALLOCATOR_MALLOC,
390 			    name, mp_maxcpus);
391 		if (mtp == NULL) {
392 			_memstat_mtl_empty(list);
393 			list->mtl_error = MEMSTAT_ERROR_NOMEMORY;
394 			return (-1);
395 		}
396 
397 		/*
398 		 * This logic is replicated from kern_malloc.c, and should
399 		 * be kept in sync.
400 		 */
401 		_memstat_mt_reset_stats(mtp, mp_maxcpus);
402 		for (j = 0; j < mp_ncpus; j++) {
403 			ret = kread_zpcpu(kvm, (u_long)mtip->mti_stats, &mts,
404 			    sizeof(mts), j);
405 			if (ret != 0) {
406 				_memstat_mtl_empty(list);
407 				list->mtl_error = ret;
408 				return (-1);
409 			}
410 			mtp->mt_memalloced += mts.mts_memalloced;
411 			mtp->mt_memfreed += mts.mts_memfreed;
412 			mtp->mt_numallocs += mts.mts_numallocs;
413 			mtp->mt_numfrees += mts.mts_numfrees;
414 			mtp->mt_sizemask |= mts.mts_size;
415 
416 			mtp->mt_percpu_alloc[j].mtp_memalloced =
417 			    mts.mts_memalloced;
418 			mtp->mt_percpu_alloc[j].mtp_memfreed =
419 			    mts.mts_memfreed;
420 			mtp->mt_percpu_alloc[j].mtp_numallocs =
421 			    mts.mts_numallocs;
422 			mtp->mt_percpu_alloc[j].mtp_numfrees =
423 			    mts.mts_numfrees;
424 			mtp->mt_percpu_alloc[j].mtp_sizemask =
425 			    mts.mts_size;
426 		}
427 		for (; j < mp_maxcpus; j++) {
428 			bzero(&mtp->mt_percpu_alloc[j],
429 			    sizeof(mtp->mt_percpu_alloc[0]));
430 		}
431 
432 		mtp->mt_bytes = mtp->mt_memalloced - mtp->mt_memfreed;
433 		mtp->mt_count = mtp->mt_numallocs - mtp->mt_numfrees;
434 	}
435 
436 	return (0);
437 }
438 
439 static int
440 memstat_malloc_zone_init(void)
441 {
442 	size_t size;
443 
444 	size = sizeof(memstat_malloc_zone_count);
445 	if (sysctlbyname("vm.malloc.zone_count", &memstat_malloc_zone_count,
446 	    &size, NULL, 0) < 0) {
447 		return (-1);
448 	}
449 
450 	if (memstat_malloc_zone_count > (int)nitems(memstat_malloc_zone_sizes)) {
451 		return (-1);
452 	}
453 
454 	size = sizeof(memstat_malloc_zone_sizes);
455 	if (sysctlbyname("vm.malloc.zone_sizes", &memstat_malloc_zone_sizes,
456 	    &size, NULL, 0) < 0) {
457 		return (-1);
458 	}
459 
460 	return (0);
461 }
462 
463 /*
464  * Copied from kern_malloc.c
465  *
466  * kz_zone is an array sized at compilation time, the size is exported in
467  * "numzones". Below we need to iterate kz_size.
468  */
469 struct memstat_kmemzone {
470 	int kz_size;
471 	const char *kz_name;
472 	void *kz_zone[1];
473 };
474 
475 static int
476 memstat_malloc_zone_init_kvm(kvm_t *kvm)
477 {
478 	struct memstat_kmemzone *kmemzones, *kz;
479 	int numzones, objsize, allocsize, ret;
480 	int i;
481 
482 	ret = kread_symbol(kvm, X_VM_MALLOC_ZONE_COUNT,
483 	    &memstat_malloc_zone_count, sizeof(memstat_malloc_zone_count), 0);
484 	if (ret != 0) {
485 		return (ret);
486 	}
487 
488 	ret = kread_symbol(kvm, X_NUMZONES, &numzones, sizeof(numzones), 0);
489 	if (ret != 0) {
490 		return (ret);
491 	}
492 
493 	objsize = __offsetof(struct memstat_kmemzone, kz_zone) +
494 	    sizeof(void *) * numzones;
495 
496 	allocsize = objsize * memstat_malloc_zone_count;
497 	kmemzones = malloc(allocsize);
498 	if (kmemzones == NULL) {
499 		return (MEMSTAT_ERROR_NOMEMORY);
500 	}
501 	ret = kread_symbol(kvm, X_KMEMZONES, kmemzones, allocsize, 0);
502 	if (ret != 0) {
503 		free(kmemzones);
504 		return (ret);
505 	}
506 
507 	kz = kmemzones;
508 	for (i = 0; i < (int)nitems(memstat_malloc_zone_sizes); i++) {
509 		memstat_malloc_zone_sizes[i] = kz->kz_size;
510 		kz = (struct memstat_kmemzone *)((char *)kz + objsize);
511 	}
512 
513 	free(kmemzones);
514 	return (0);
515 }
516 
517 size_t
518 memstat_malloc_zone_get_count(void)
519 {
520 
521 	return (memstat_malloc_zone_count);
522 }
523 
524 size_t
525 memstat_malloc_zone_get_size(size_t n)
526 {
527 
528 	if (n >= nitems(memstat_malloc_zone_sizes)) {
529 		return (-1);
530 	}
531 
532 	return (memstat_malloc_zone_sizes[n]);
533 }
534 
535 int
536 memstat_malloc_zone_used(const struct memory_type *mtp, size_t n)
537 {
538 
539 	if (memstat_get_sizemask(mtp) & (1 << n))
540 		return (1);
541 
542 	return (0);
543 }
544