uma_dbg.c revision 139825 
1/*-
2 * Copyright (c) 2004, 2005,
3 *     Bosko Milekic <bmilekic@freebsd.org>
4 * Copyright (c) 2002, 2003, 2004, 2005,
5 *     Jeffrey Roberson <jeff@freebsd.org>
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 unmodified, this list of conditions, and the following
12 *    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 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/*
30 * uma_dbg.c	Debugging features for UMA users
31 *
32 */
33
34#include <sys/cdefs.h>
35__FBSDID("$FreeBSD: head/sys/vm/uma_dbg.c 139825 2005-01-07 02:29:27Z imp $");
36
37#include <sys/param.h>
38#include <sys/systm.h>
39#include <sys/kernel.h>
40#include <sys/types.h>
41#include <sys/queue.h>
42#include <sys/lock.h>
43#include <sys/mutex.h>
44#include <sys/malloc.h>
45
46#include <vm/vm.h>
47#include <vm/vm_object.h>
48#include <vm/vm_page.h>
49#include <vm/uma.h>
50#include <vm/uma_int.h>
51#include <vm/uma_dbg.h>
52
53static const u_int32_t uma_junk = 0xdeadc0de;
54
55/*
56 * Checks an item to make sure it hasn't been overwritten since it was freed,
57 * prior to subsequent reallocation.
58 *
59 * Complies with standard ctor arg/return
60 *
61 */
62int
63trash_ctor(void *mem, int size, void *arg, int flags)
64{
65	int cnt;
66	u_int32_t *p;
67
68	cnt = size / sizeof(uma_junk);
69
70	for (p = mem; cnt > 0; cnt--, p++)
71		if (*p != uma_junk)
72			panic("Memory modified after free %p(%d) val=%x @ %p\n",
73			    mem, size, *p, p);
74	return (0);
75}
76
77/*
78 * Fills an item with predictable garbage
79 *
80 * Complies with standard dtor arg/return
81 *
82 */
83void
84trash_dtor(void *mem, int size, void *arg)
85{
86	int cnt;
87	u_int32_t *p;
88
89	cnt = size / sizeof(uma_junk);
90
91	for (p = mem; cnt > 0; cnt--, p++)
92		*p = uma_junk;
93}
94
95/*
96 * Fills an item with predictable garbage
97 *
98 * Complies with standard init arg/return
99 *
100 */
101int
102trash_init(void *mem, int size, int flags)
103{
104	trash_dtor(mem, size, NULL);
105	return (0);
106}
107
108/*
109 * Checks an item to make sure it hasn't been overwritten since it was freed.
110 *
111 * Complies with standard fini arg/return
112 *
113 */
114void
115trash_fini(void *mem, int size)
116{
117	(void)trash_ctor(mem, size, NULL, 0);
118}
119
120int
121mtrash_ctor(void *mem, int size, void *arg, int flags)
122{
123	struct malloc_type **ksp;
124	u_int32_t *p = mem;
125	int cnt;
126
127	size -= sizeof(struct malloc_type *);
128	ksp = (struct malloc_type **)mem;
129	ksp += size / sizeof(struct malloc_type *);
130	cnt = size / sizeof(uma_junk);
131
132	for (p = mem; cnt > 0; cnt--, p++)
133		if (*p != uma_junk) {
134			printf("Memory modified after free %p(%d) val=%x @ %p\n",
135			    mem, size, *p, p);
136			panic("Most recently used by %s\n", (*ksp == NULL)?
137			    "none" : (*ksp)->ks_shortdesc);
138		}
139	return (0);
140}
141
142/*
143 * Fills an item with predictable garbage
144 *
145 * Complies with standard dtor arg/return
146 *
147 */
148void
149mtrash_dtor(void *mem, int size, void *arg)
150{
151	int cnt;
152	u_int32_t *p;
153
154	size -= sizeof(struct malloc_type *);
155	cnt = size / sizeof(uma_junk);
156
157	for (p = mem; cnt > 0; cnt--, p++)
158		*p = uma_junk;
159}
160
161/*
162 * Fills an item with predictable garbage
163 *
164 * Complies with standard init arg/return
165 *
166 */
167int
168mtrash_init(void *mem, int size, int flags)
169{
170	struct malloc_type **ksp;
171
172	mtrash_dtor(mem, size, NULL);
173
174	ksp = (struct malloc_type **)mem;
175	ksp += (size / sizeof(struct malloc_type *)) - 1;
176	*ksp = NULL;
177	return (0);
178}
179
180/*
181 * Checks an item to make sure it hasn't been overwritten since it was freed,
182 * prior to freeing it back to available memory.
183 *
184 * Complies with standard fini arg/return
185 *
186 */
187void
188mtrash_fini(void *mem, int size)
189{
190	(void)mtrash_ctor(mem, size, NULL, 0);
191}
192
193static uma_slab_t
194uma_dbg_getslab(uma_zone_t zone, void *item)
195{
196	uma_slab_t slab;
197	uma_keg_t keg;
198	u_int8_t *mem;
199
200	keg = zone->uz_keg;
201	mem = (u_int8_t *)((unsigned long)item & (~UMA_SLAB_MASK));
202	if (keg->uk_flags & UMA_ZONE_MALLOC) {
203		slab = vtoslab((vm_offset_t)mem);
204	} else if (keg->uk_flags & UMA_ZONE_HASH) {
205		slab = hash_sfind(&keg->uk_hash, mem);
206	} else {
207		mem += keg->uk_pgoff;
208		slab = (uma_slab_t)mem;
209	}
210
211	return (slab);
212}
213
214/*
215 * Set up the slab's freei data such that uma_dbg_free can function.
216 *
217 */
218
219void
220uma_dbg_alloc(uma_zone_t zone, uma_slab_t slab, void *item)
221{
222	uma_keg_t keg;
223	uma_slabrefcnt_t slabref;
224	int freei;
225
226	keg = zone->uz_keg;
227	if (slab == NULL) {
228		slab = uma_dbg_getslab(zone, item);
229		if (slab == NULL)
230			panic("uma: item %p did not belong to zone %s\n",
231			    item, zone->uz_name);
232	}
233
234	freei = ((unsigned long)item - (unsigned long)slab->us_data)
235	    / keg->uk_rsize;
236
237	if (keg->uk_flags & UMA_ZONE_REFCNT) {
238		slabref = (uma_slabrefcnt_t)slab;
239		slabref->us_freelist[freei].us_item = 255;
240	} else {
241		slab->us_freelist[freei].us_item = 255;
242	}
243
244	return;
245}
246
247/*
248 * Verifies freed addresses.  Checks for alignment, valid slab membership
249 * and duplicate frees.
250 *
251 */
252
253void
254uma_dbg_free(uma_zone_t zone, uma_slab_t slab, void *item)
255{
256	uma_keg_t keg;
257	uma_slabrefcnt_t slabref;
258	int freei;
259
260	keg = zone->uz_keg;
261	if (slab == NULL) {
262		slab = uma_dbg_getslab(zone, item);
263		if (slab == NULL)
264			panic("uma: Freed item %p did not belong to zone %s\n",
265			    item, zone->uz_name);
266	}
267
268	freei = ((unsigned long)item - (unsigned long)slab->us_data)
269	    / keg->uk_rsize;
270
271	if (freei >= keg->uk_ipers)
272		panic("zone: %s(%p) slab %p freelist %d out of range 0-%d\n",
273		    zone->uz_name, zone, slab, freei, keg->uk_ipers-1);
274
275	if (((freei * keg->uk_rsize) + slab->us_data) != item) {
276		printf("zone: %s(%p) slab %p freed address %p unaligned.\n",
277		    zone->uz_name, zone, slab, item);
278		panic("should be %p\n",
279		    (freei * keg->uk_rsize) + slab->us_data);
280	}
281
282	if (keg->uk_flags & UMA_ZONE_REFCNT) {
283		slabref = (uma_slabrefcnt_t)slab;
284		if (slabref->us_freelist[freei].us_item != 255) {
285			printf("Slab at %p, freei %d = %d.\n",
286			    slab, freei, slabref->us_freelist[freei].us_item);
287			panic("Duplicate free of item %p from zone %p(%s)\n",
288			    item, zone, zone->uz_name);
289		}
290
291		/*
292		 * When this is actually linked into the slab this will change.
293		 * Until then the count of valid slabs will make sure we don't
294		 * accidentally follow this and assume it's a valid index.
295		 */
296		slabref->us_freelist[freei].us_item = 0;
297	} else {
298		if (slab->us_freelist[freei].us_item != 255) {
299			printf("Slab at %p, freei %d = %d.\n",
300			    slab, freei, slab->us_freelist[freei].us_item);
301			panic("Duplicate free of item %p from zone %p(%s)\n",
302			    item, zone, zone->uz_name);
303		}
304
305		/*
306		 * When this is actually linked into the slab this will change.
307		 * Until then the count of valid slabs will make sure we don't
308		 * accidentally follow this and assume it's a valid index.
309		 */
310		slab->us_freelist[freei].us_item = 0;
311	}
312}
313