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/bitset.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
53 static const uint32_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 */
62 int
trash_ctor(void * mem,int size,void * arg,int flags)63 trash_ctor(void *mem, int size, void *arg, int flags)
64 {
65 int cnt;
66 uint32_t *p;
67
68 cnt = size / sizeof(uma_junk);
69
70 for (p = mem; cnt > 0; cnt--, p++)
71 if (*p != uma_junk) {
72 #ifdef INVARIANTS
73 panic("Memory modified after free %p(%d) val=%x @ %p\n",
74 mem, size, *p, p);
75 #else
76 printf("Memory modified after free %p(%d) val=%x @ %p\n",
77 mem, size, *p, p);
78 #endif
79 return (0);
80 }
81 return (0);
82 }
83
84 /*
85 * Fills an item with predictable garbage
86 *
87 * Complies with standard dtor arg/return
88 *
89 */
90 void
trash_dtor(void * mem,int size,void * arg)91 trash_dtor(void *mem, int size, void *arg)
92 {
93 int cnt;
94 uint32_t *p;
95
96 cnt = size / sizeof(uma_junk);
97
98 for (p = mem; cnt > 0; cnt--, p++)
99 *p = uma_junk;
100 }
101
102 /*
103 * Fills an item with predictable garbage
104 *
105 * Complies with standard init arg/return
106 *
107 */
108 int
trash_init(void * mem,int size,int flags)109 trash_init(void *mem, int size, int flags)
110 {
111 trash_dtor(mem, size, NULL);
112 return (0);
113 }
114
115 /*
116 * Checks an item to make sure it hasn't been overwritten since it was freed.
117 *
118 * Complies with standard fini arg/return
119 *
120 */
121 void
trash_fini(void * mem,int size)122 trash_fini(void *mem, int size)
123 {
124 (void)trash_ctor(mem, size, NULL, 0);
125 }
126
127 int
mtrash_ctor(void * mem,int size,void * arg,int flags)128 mtrash_ctor(void *mem, int size, void *arg, int flags)
129 {
130 struct malloc_type **ksp;
131 uint32_t *p = mem;
132 int cnt;
133
134 size -= sizeof(struct malloc_type *);
135 ksp = (struct malloc_type **)mem;
136 ksp += size / sizeof(struct malloc_type *);
137 cnt = size / sizeof(uma_junk);
138
139 for (p = mem; cnt > 0; cnt--, p++)
140 if (*p != uma_junk) {
141 printf("Memory modified after free %p(%d) val=%x @ %p\n",
142 mem, size, *p, p);
143 panic("Most recently used by %s\n", (*ksp == NULL)?
144 "none" : (*ksp)->ks_shortdesc);
145 }
146 return (0);
147 }
148
149 /*
150 * Fills an item with predictable garbage
151 *
152 * Complies with standard dtor arg/return
153 *
154 */
155 void
mtrash_dtor(void * mem,int size,void * arg)156 mtrash_dtor(void *mem, int size, void *arg)
157 {
158 int cnt;
159 uint32_t *p;
160
161 size -= sizeof(struct malloc_type *);
162 cnt = size / sizeof(uma_junk);
163
164 for (p = mem; cnt > 0; cnt--, p++)
165 *p = uma_junk;
166 }
167
168 /*
169 * Fills an item with predictable garbage
170 *
171 * Complies with standard init arg/return
172 *
173 */
174 int
mtrash_init(void * mem,int size,int flags)175 mtrash_init(void *mem, int size, int flags)
176 {
177 struct malloc_type **ksp;
178
179 mtrash_dtor(mem, size, NULL);
180
181 ksp = (struct malloc_type **)mem;
182 ksp += (size / sizeof(struct malloc_type *)) - 1;
183 *ksp = NULL;
184 return (0);
185 }
186
187 /*
188 * Checks an item to make sure it hasn't been overwritten since it was freed,
189 * prior to freeing it back to available memory.
190 *
191 * Complies with standard fini arg/return
192 *
193 */
194 void
mtrash_fini(void * mem,int size)195 mtrash_fini(void *mem, int size)
196 {
197 (void)mtrash_ctor(mem, size, NULL, 0);
198 }
199
200 #ifdef INVARIANTS
201 static uma_slab_t
uma_dbg_getslab(uma_zone_t zone,void * item)202 uma_dbg_getslab(uma_zone_t zone, void *item)
203 {
204 uma_slab_t slab;
205 uma_keg_t keg;
206 uint8_t *mem;
207
208 mem = (uint8_t *)((uintptr_t)item & (~UMA_SLAB_MASK));
209 if (zone->uz_flags & UMA_ZONE_VTOSLAB) {
210 slab = vtoslab((vm_offset_t)mem);
211 } else {
212 /*
213 * It is safe to return the slab here even though the
214 * zone is unlocked because the item's allocation state
215 * essentially holds a reference.
216 */
217 ZONE_LOCK(zone);
218 keg = LIST_FIRST(&zone->uz_kegs)->kl_keg;
219 if (keg->uk_flags & UMA_ZONE_HASH)
220 slab = hash_sfind(&keg->uk_hash, mem);
221 else
222 slab = (uma_slab_t)(mem + keg->uk_pgoff);
223 ZONE_UNLOCK(zone);
224 }
225
226 return (slab);
227 }
228
229 /*
230 * Set up the slab's freei data such that uma_dbg_free can function.
231 *
232 */
233 void
uma_dbg_alloc(uma_zone_t zone,uma_slab_t slab,void * item)234 uma_dbg_alloc(uma_zone_t zone, uma_slab_t slab, void *item)
235 {
236 uma_keg_t keg;
237 int freei;
238
239 if (zone_first_keg(zone) == NULL)
240 return;
241 if (slab == NULL) {
242 slab = uma_dbg_getslab(zone, item);
243 if (slab == NULL)
244 panic("uma: item %p did not belong to zone %s\n",
245 item, zone->uz_name);
246 }
247 keg = slab->us_keg;
248 freei = ((uintptr_t)item - (uintptr_t)slab->us_data) / keg->uk_rsize;
249
250 if (BIT_ISSET(SLAB_SETSIZE, freei, &slab->us_debugfree))
251 panic("Duplicate alloc of %p from zone %p(%s) slab %p(%d)\n",
252 item, zone, zone->uz_name, slab, freei);
253 BIT_SET_ATOMIC(SLAB_SETSIZE, freei, &slab->us_debugfree);
254
255 return;
256 }
257
258 /*
259 * Verifies freed addresses. Checks for alignment, valid slab membership
260 * and duplicate frees.
261 *
262 */
263 void
uma_dbg_free(uma_zone_t zone,uma_slab_t slab,void * item)264 uma_dbg_free(uma_zone_t zone, uma_slab_t slab, void *item)
265 {
266 uma_keg_t keg;
267 int freei;
268
269 if (zone_first_keg(zone) == NULL)
270 return;
271 if (slab == NULL) {
272 slab = uma_dbg_getslab(zone, item);
273 if (slab == NULL)
274 panic("uma: Freed item %p did not belong to zone %s\n",
275 item, zone->uz_name);
276 }
277 keg = slab->us_keg;
278 freei = ((uintptr_t)item - (uintptr_t)slab->us_data) / keg->uk_rsize;
279
280 if (freei >= keg->uk_ipers)
281 panic("Invalid free of %p from zone %p(%s) slab %p(%d)\n",
282 item, zone, zone->uz_name, slab, freei);
283
284 if (((freei * keg->uk_rsize) + slab->us_data) != item)
285 panic("Unaligned free of %p from zone %p(%s) slab %p(%d)\n",
286 item, zone, zone->uz_name, slab, freei);
287
288 if (!BIT_ISSET(SLAB_SETSIZE, freei, &slab->us_debugfree))
289 panic("Duplicate free of %p from zone %p(%s) slab %p(%d)\n",
290 item, zone, zone->uz_name, slab, freei);
291
292 BIT_CLR_ATOMIC(SLAB_SETSIZE, freei, &slab->us_debugfree);
293 }
294
295 #endif /* INVARIANTS */
296