Super User's BSD Cross Reference: /FreeBSD/stand/libsa/zalloc_malloc.c

1 /*
2 * This module derived from code donated to the FreeBSD Project by
3 * Matthew Dillon <dillon@backplane.com>
4 *
5 * Copyright (c) 1998 The FreeBSD Project
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, this list of conditions and the following 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 AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32
33 /*
34 * MALLOC.C - malloc equivalent, runs on top of zalloc and uses sbrk
35 */
36
37#include "zalloc_defs.h"
38
39 static MemPool MallocPool;
40
41#ifdef DMALLOCDEBUG
42 static int MallocMax;
43 static int MallocCount;
44
45 void mallocstats(void);
46#endif
47
48#ifdef malloc
49#undef malloc
50#undef free
51#endif
52
53 static void *Malloc_align(size_t, size_t);
54
55#ifndef MIN
56# define MIN(a,b) ((a) <= (b)) ? (a) : (b)
57#endif
58
59 void *
60 Malloc(size_t bytes, const char *file __unused, int line __unused)
61{
62 return (Malloc_align(bytes, 1));
63}
64
65 void *
66 Memalign(size_t alignment, size_t bytes, const char *file __unused,
67 int line __unused)
68{
69 if (alignment == 0)
70 alignment = 1;
71
72 return (Malloc_align(bytes, alignment));
73}
74
75 static void *
76 Malloc_align(size_t bytes, size_t alignment)
77{
78 Guard *res;
79
80#ifdef USEENDGUARD
81 bytes += MALLOCALIGN + 1;
82#else
83 bytes += MALLOCALIGN;
84#endif
85
86 while ((res = znalloc(&MallocPool, bytes, alignment)) == NULL) {
87 int incr = (bytes + BLKEXTENDMASK) & ~BLKEXTENDMASK;
88 char *base;
89
90 if ((base = sbrk(incr)) == (char *)-1)
91 return (NULL);
92 zextendPool(&MallocPool, base, incr);
93 zfree(&MallocPool, base, incr);
94 }
95#ifdef DMALLOCDEBUG
96 if (++MallocCount > MallocMax)
97 MallocMax = MallocCount;
98#endif
99#ifdef USEGUARD
100 res->ga_Magic = GAMAGIC;
101#endif
102 res->ga_Bytes = bytes;
103#ifdef USEENDGUARD
104 *((signed char *)res + bytes - 1) = -2;
105#endif
106
107 return ((char *)res + MALLOCALIGN);
108}
109
110 void
111 Free(void *ptr, const char *file, int line)
112{
113 size_t bytes;
114
115 if (ptr != NULL) {
116 Guard *res = (void *)((char *)ptr - MALLOCALIGN);
117
118 if (file == NULL)
119 file = "unknown";
120#ifdef USEGUARD
121 if (res->ga_Magic == GAFREE) {
122 printf("free: duplicate free @ %p from %s:%d\n",
123 ptr, file, line);
124 return;
125 }
126 if (res->ga_Magic != GAMAGIC) {
127 size_t dump_bytes;
128
129 dump_bytes = MIN((ptr - MallocPool.mp_Base), 512);
130 hexdump(ptr - dump_bytes, dump_bytes);
131 panic("free: guard1 fail @ %p from %s:%d",
132 ptr, file, line);
133 }
134 res->ga_Magic = GAFREE;
135#endif
136#ifdef USEENDGUARD
137 if (*((signed char *)res + res->ga_Bytes - 1) == -1) {
138 printf("free: duplicate2 free @ %p from %s:%d\n",
139 ptr, file, line);
140 return;
141 }
142 if (*((signed char *)res + res->ga_Bytes - 1) != -2)
143 panic("free: guard2 fail @ %p + %zu from %s:%d",
144 ptr, res->ga_Bytes - MALLOCALIGN, file, line);
145 *((signed char *)res + res->ga_Bytes - 1) = -1;
146#endif
147
148 bytes = res->ga_Bytes;
149 zfree(&MallocPool, res, bytes);
150#ifdef DMALLOCDEBUG
151 --MallocCount;
152#endif
153 }
154}
155
156
157 void *
158 Calloc(size_t n1, size_t n2, const char *file, int line)
159{
160 uintptr_t bytes = (uintptr_t)n1 * (uintptr_t)n2;
161 void *res;
162
163 if ((res = Malloc(bytes, file, line)) != NULL) {
164 bzero(res, bytes);
165#ifdef DMALLOCDEBUG
166 if (++MallocCount > MallocMax)
167 MallocMax = MallocCount;
168#endif
169 }
170 return (res);
171}
172
173 /*
174 * realloc() - I could be fancier here and free the old buffer before
175 * allocating the new one (saving potential fragmentation
176 * and potential buffer copies). But I don't bother.
177 */
178
179 void *
180 Realloc(void *ptr, size_t size, const char *file, int line)
181{
182 void *res;
183 size_t old;
184
185 if ((res = Malloc(size, file, line)) != NULL) {
186 if (ptr != NULL) {
187 Guard *g = (Guard *)((char *)ptr - MALLOCALIGN);
188
189 old = g->ga_Bytes - MALLOCALIGN;
190 if (old < size)
191 bcopy(ptr, res, old);
192 else
193 bcopy(ptr, res, size);
194 Free(ptr, file, line);
195 } else {
196#ifdef DMALLOCDEBUG
197 if (++MallocCount > MallocMax)
198 MallocMax = MallocCount;
199#ifdef EXITSTATS
200 if (DidAtExit == 0) {
201 DidAtExit = 1;
202 atexit(mallocstats);
203 }
204#endif
205#endif
206 }
207 }
208 return (res);
209}
210
211 void *
212 Reallocf(void *ptr, size_t size, const char *file, int line)
213{
214 void *res;
215
216 if ((res = Realloc(ptr, size, file, line)) == NULL)
217 Free(ptr, file, line);
218 return (res);
219}
220
221#ifdef DMALLOCDEBUG
222
223 void
224 mallocstats(void)
225{
226 printf("Active Allocations: %d/%d\n", MallocCount, MallocMax);
227#ifdef ZALLOCDEBUG
228 zallocstats(&MallocPool);
229#endif
230}
231
232#endif
233 

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