xref: /freebsd/sys/vm/uma_dbg.c (revision 63a938566d524836885917d95bd491aa4400b181)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2002, 2003, 2004, 2005 Jeffrey Roberson <jeff@FreeBSD.org>
5  * Copyright (c) 2004, 2005 Bosko Milekic <bmilekic@FreeBSD.org>
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 unmodified, this list of conditions, and the following
13  *    disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 /*
31  * uma_dbg.c	Debugging features for UMA users
32  *
33  */
34 
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 
38 #include "opt_vm.h"
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/bitset.h>
43 #include <sys/kernel.h>
44 #include <sys/types.h>
45 #include <sys/queue.h>
46 #include <sys/lock.h>
47 #include <sys/mutex.h>
48 #include <sys/malloc.h>
49 
50 #include <vm/vm.h>
51 #include <vm/vm_object.h>
52 #include <vm/vm_page.h>
53 #include <vm/uma.h>
54 #include <vm/uma_int.h>
55 #include <vm/uma_dbg.h>
56 #include <vm/memguard.h>
57 
58 static const uint32_t uma_junk = 0xdeadc0de;
59 
60 /*
61  * Checks an item to make sure it hasn't been overwritten since it was freed,
62  * prior to subsequent reallocation.
63  *
64  * Complies with standard ctor arg/return
65  */
66 int
67 trash_ctor(void *mem, int size, void *arg, int flags)
68 {
69 	int cnt;
70 	uint32_t *p;
71 
72 #ifdef DEBUG_MEMGUARD
73 	if (is_memguard_addr(mem))
74 		return (0);
75 #endif
76 
77 	cnt = size / sizeof(uma_junk);
78 
79 	for (p = mem; cnt > 0; cnt--, p++)
80 		if (*p != uma_junk) {
81 #ifdef INVARIANTS
82 			panic("Memory modified after free %p(%d) val=%x @ %p\n",
83 			    mem, size, *p, p);
84 #else
85 			printf("Memory modified after free %p(%d) val=%x @ %p\n",
86 			    mem, size, *p, p);
87 #endif
88 			return (0);
89 		}
90 	return (0);
91 }
92 
93 /*
94  * Fills an item with predictable garbage
95  *
96  * Complies with standard dtor arg/return
97  *
98  */
99 void
100 trash_dtor(void *mem, int size, void *arg)
101 {
102 	int cnt;
103 	uint32_t *p;
104 
105 #ifdef DEBUG_MEMGUARD
106 	if (is_memguard_addr(mem))
107 		return;
108 #endif
109 
110 	cnt = size / sizeof(uma_junk);
111 
112 	for (p = mem; cnt > 0; cnt--, p++)
113 		*p = uma_junk;
114 }
115 
116 /*
117  * Fills an item with predictable garbage
118  *
119  * Complies with standard init arg/return
120  *
121  */
122 int
123 trash_init(void *mem, int size, int flags)
124 {
125 	trash_dtor(mem, size, NULL);
126 	return (0);
127 }
128 
129 /*
130  * Checks an item to make sure it hasn't been overwritten since it was freed.
131  *
132  * Complies with standard fini arg/return
133  *
134  */
135 void
136 trash_fini(void *mem, int size)
137 {
138 	(void)trash_ctor(mem, size, NULL, 0);
139 }
140 
141 int
142 mtrash_ctor(void *mem, int size, void *arg, int flags)
143 {
144 	struct malloc_type **ksp;
145 	uint32_t *p = mem;
146 	int cnt;
147 
148 #ifdef DEBUG_MEMGUARD
149 	if (is_memguard_addr(mem))
150 		return (0);
151 #endif
152 
153 	size -= sizeof(struct malloc_type *);
154 	ksp = (struct malloc_type **)mem;
155 	ksp += size / sizeof(struct malloc_type *);
156 	cnt = size / sizeof(uma_junk);
157 
158 	for (p = mem; cnt > 0; cnt--, p++)
159 		if (*p != uma_junk) {
160 			printf("Memory modified after free %p(%d) val=%x @ %p\n",
161 			    mem, size, *p, p);
162 			panic("Most recently used by %s\n", (*ksp == NULL)?
163 			    "none" : (*ksp)->ks_shortdesc);
164 		}
165 	return (0);
166 }
167 
168 /*
169  * Fills an item with predictable garbage
170  *
171  * Complies with standard dtor arg/return
172  *
173  */
174 void
175 mtrash_dtor(void *mem, int size, void *arg)
176 {
177 	int cnt;
178 	uint32_t *p;
179 
180 #ifdef DEBUG_MEMGUARD
181 	if (is_memguard_addr(mem))
182 		return;
183 #endif
184 
185 	size -= sizeof(struct malloc_type *);
186 	cnt = size / sizeof(uma_junk);
187 
188 	for (p = mem; cnt > 0; cnt--, p++)
189 		*p = uma_junk;
190 }
191 
192 /*
193  * Fills an item with predictable garbage
194  *
195  * Complies with standard init arg/return
196  *
197  */
198 int
199 mtrash_init(void *mem, int size, int flags)
200 {
201 	struct malloc_type **ksp;
202 
203 #ifdef DEBUG_MEMGUARD
204 	if (is_memguard_addr(mem))
205 		return (0);
206 #endif
207 
208 	mtrash_dtor(mem, size, NULL);
209 
210 	ksp = (struct malloc_type **)mem;
211 	ksp += (size / sizeof(struct malloc_type *)) - 1;
212 	*ksp = NULL;
213 	return (0);
214 }
215 
216 /*
217  * Checks an item to make sure it hasn't been overwritten since it was freed,
218  * prior to freeing it back to available memory.
219  *
220  * Complies with standard fini arg/return
221  *
222  */
223 void
224 mtrash_fini(void *mem, int size)
225 {
226 	(void)mtrash_ctor(mem, size, NULL, 0);
227 }
228