FreeBSD/Linux Kernel Cross Reference
sys/vm/uma_dbg.c
1 /*-
2 * Copyright (c) 2002, 2003, 2004, 2005 Jeffrey Roberson <jeff@FreeBSD.org>
3 * Copyright (c) 2004, 2005 Bosko Milekic <bmilekic@FreeBSD.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice unmodified, this list of conditions, and the following
11 * 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 ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28 /*
29 * uma_dbg.c Debugging features for UMA users
30 *
31 */
32
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/kernel.h>
39 #include <sys/types.h>
40 #include <sys/queue.h>
41 #include <sys/lock.h>
42 #include <sys/mutex.h>
43 #include <sys/malloc.h>
44
45 #include <vm/vm.h>
46 #include <vm/vm_object.h>
47 #include <vm/vm_page.h>
48 #include <vm/uma.h>
49 #include <vm/uma_int.h>
50 #include <vm/uma_dbg.h>
51
52 static const u_int32_t uma_junk = 0xdeadc0de;
53
54 /*
55 * Checks an item to make sure it hasn't been overwritten since it was freed,
56 * prior to subsequent reallocation.
57 *
58 * Complies with standard ctor arg/return
59 *
60 */
61 int
62 trash_ctor(void *mem, int size, void *arg, int flags)
63 {
64 int cnt;
65 u_int32_t *p;
66
67 cnt = size / sizeof(uma_junk);
68
69 for (p = mem; cnt > 0; cnt--, p++)
70 if (*p != uma_junk) {
71 printf("Memory modified after free %p(%d) val=%x @ %p\n",
72 mem, size, *p, p);
73 return (0);
74 }
75 return (0);
76 }
77
78 /*
79 * Fills an item with predictable garbage
80 *
81 * Complies with standard dtor arg/return
82 *
83 */
84 void
85 trash_dtor(void *mem, int size, void *arg)
86 {
87 int cnt;
88 u_int32_t *p;
89
90 cnt = size / sizeof(uma_junk);
91
92 for (p = mem; cnt > 0; cnt--, p++)
93 *p = uma_junk;
94 }
95
96 /*
97 * Fills an item with predictable garbage
98 *
99 * Complies with standard init arg/return
100 *
101 */
102 int
103 trash_init(void *mem, int size, int flags)
104 {
105 trash_dtor(mem, size, NULL);
106 return (0);
107 }
108
109 /*
110 * Checks an item to make sure it hasn't been overwritten since it was freed.
111 *
112 * Complies with standard fini arg/return
113 *
114 */
115 void
116 trash_fini(void *mem, int size)
117 {
118 (void)trash_ctor(mem, size, NULL, 0);
119 }
120
121 int
122 mtrash_ctor(void *mem, int size, void *arg, int flags)
123 {
124 struct malloc_type **ksp;
125 u_int32_t *p = mem;
126 int cnt;
127
128 size -= sizeof(struct malloc_type *);
129 ksp = (struct malloc_type **)mem;
130 ksp += size / sizeof(struct malloc_type *);
131 cnt = size / sizeof(uma_junk);
132
133 for (p = mem; cnt > 0; cnt--, p++)
134 if (*p != uma_junk) {
135 printf("Memory modified after free %p(%d) val=%x @ %p\n",
136 mem, size, *p, p);
137 panic("Most recently used by %s\n", (*ksp == NULL)?
138 "none" : (*ksp)->ks_shortdesc);
139 }
140 return (0);
141 }
142
143 /*
144 * Fills an item with predictable garbage
145 *
146 * Complies with standard dtor arg/return
147 *
148 */
149 void
150 mtrash_dtor(void *mem, int size, void *arg)
151 {
152 int cnt;
153 u_int32_t *p;
154
155 size -= sizeof(struct malloc_type *);
156 cnt = size / sizeof(uma_junk);
157
158 for (p = mem; cnt > 0; cnt--, p++)
159 *p = uma_junk;
160 }
161
162 /*
163 * Fills an item with predictable garbage
164 *
165 * Complies with standard init arg/return
166 *
167 */
168 int
169 mtrash_init(void *mem, int size, int flags)
170 {
171 struct malloc_type **ksp;
172
173 mtrash_dtor(mem, size, NULL);
174
175 ksp = (struct malloc_type **)mem;
176 ksp += (size / sizeof(struct malloc_type *)) - 1;
177 *ksp = NULL;
178 return (0);
179 }
180
181 /*
182 * Checks an item to make sure it hasn't been overwritten since it was freed,
183 * prior to freeing it back to available memory.
184 *
185 * Complies with standard fini arg/return
186 *
187 */
188 void
189 mtrash_fini(void *mem, int size)
190 {
191 (void)mtrash_ctor(mem, size, NULL, 0);
192 }
193
194 static uma_slab_t
195 uma_dbg_getslab(uma_zone_t zone, void *item)
196 {
197 uma_slab_t slab;
198 uma_keg_t keg;
199 u_int8_t *mem;
200
201 keg = zone->uz_keg;
202 mem = (u_int8_t *)((unsigned long)item & (~UMA_SLAB_MASK));
203 if (keg->uk_flags & UMA_ZONE_MALLOC) {
204 slab = vtoslab((vm_offset_t)mem);
205 } else if (keg->uk_flags & UMA_ZONE_HASH) {
206 slab = hash_sfind(&keg->uk_hash, mem);
207 } else {
208 mem += keg->uk_pgoff;
209 slab = (uma_slab_t)mem;
210 }
211
212 return (slab);
213 }
214
215 /*
216 * Set up the slab's freei data such that uma_dbg_free can function.
217 *
218 */
219
220 void
221 uma_dbg_alloc(uma_zone_t zone, uma_slab_t slab, void *item)
222 {
223 uma_keg_t keg;
224 uma_slabrefcnt_t slabref;
225 int freei;
226
227 keg = zone->uz_keg;
228 if (slab == NULL) {
229 slab = uma_dbg_getslab(zone, item);
230 if (slab == NULL)
231 panic("uma: item %p did not belong to zone %s\n",
232 item, zone->uz_name);
233 }
234
235 freei = ((unsigned long)item - (unsigned long)slab->us_data)
236 / keg->uk_rsize;
237
238 if (keg->uk_flags & UMA_ZONE_REFCNT) {
239 slabref = (uma_slabrefcnt_t)slab;
240 slabref->us_freelist[freei].us_item = 255;
241 } else {
242 slab->us_freelist[freei].us_item = 255;
243 }
244
245 return;
246 }
247
248 /*
249 * Verifies freed addresses. Checks for alignment, valid slab membership
250 * and duplicate frees.
251 *
252 */
253
254 void
255 uma_dbg_free(uma_zone_t zone, uma_slab_t slab, void *item)
256 {
257 uma_keg_t keg;
258 uma_slabrefcnt_t slabref;
259 int freei;
260
261 keg = zone->uz_keg;
262 if (slab == NULL) {
263 slab = uma_dbg_getslab(zone, item);
264 if (slab == NULL)
265 panic("uma: Freed item %p did not belong to zone %s\n",
266 item, zone->uz_name);
267 }
268
269 freei = ((unsigned long)item - (unsigned long)slab->us_data)
270 / keg->uk_rsize;
271
272 if (freei >= keg->uk_ipers)
273 panic("zone: %s(%p) slab %p freelist %d out of range 0-%d\n",
274 zone->uz_name, zone, slab, freei, keg->uk_ipers-1);
275
276 if (((freei * keg->uk_rsize) + slab->us_data) != item) {
277 printf("zone: %s(%p) slab %p freed address %p unaligned.\n",
278 zone->uz_name, zone, slab, item);
279 panic("should be %p\n",
280 (freei * keg->uk_rsize) + slab->us_data);
281 }
282
283 if (keg->uk_flags & UMA_ZONE_REFCNT) {
284 slabref = (uma_slabrefcnt_t)slab;
285 if (slabref->us_freelist[freei].us_item != 255) {
286 printf("Slab at %p, freei %d = %d.\n",
287 slab, freei, slabref->us_freelist[freei].us_item);
288 panic("Duplicate free of item %p from zone %p(%s)\n",
289 item, zone, zone->uz_name);
290 }
291
292 /*
293 * When this is actually linked into the slab this will change.
294 * Until then the count of valid slabs will make sure we don't
295 * accidentally follow this and assume it's a valid index.
296 */
297 slabref->us_freelist[freei].us_item = 0;
298 } else {
299 if (slab->us_freelist[freei].us_item != 255) {
300 printf("Slab at %p, freei %d = %d.\n",
301 slab, freei, slab->us_freelist[freei].us_item);
302 panic("Duplicate free of item %p from zone %p(%s)\n",
303 item, zone, zone->uz_name);
304 }
305
306 /*
307 * When this is actually linked into the slab this will change.
308 * Until then the count of valid slabs will make sure we don't
309 * accidentally follow this and assume it's a valid index.
310 */
311 slab->us_freelist[freei].us_item = 0;
312 }
313 }
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