xref: /freebsd/stand/libsa/zalloc_malloc.c (revision edca4938f74db18d091868237592abbf7e718669)
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 void *
56 Malloc(size_t bytes, const char *file __unused, int line __unused)
57 {
58 	return (Malloc_align(bytes, 1));
59 }
60 
61 void *
62 Memalign(size_t alignment, size_t bytes, const char *file __unused,
63     int line __unused)
64 {
65 	if (alignment == 0)
66 		alignment = 1;
67 
68 	return (Malloc_align(bytes, alignment));
69 }
70 
71 static void *
72 Malloc_align(size_t bytes, size_t alignment)
73 {
74 	Guard *res;
75 
76 #ifdef USEENDGUARD
77 	bytes += MALLOCALIGN + 1;
78 #else
79 	bytes += MALLOCALIGN;
80 #endif
81 
82 	while ((res = znalloc(&MallocPool, bytes, alignment)) == NULL) {
83 		int incr = (bytes + BLKEXTENDMASK) & ~BLKEXTENDMASK;
84 		char *base;
85 
86 		if ((base = sbrk(incr)) == (char *)-1)
87 			return (NULL);
88 		zextendPool(&MallocPool, base, incr);
89 		zfree(&MallocPool, base, incr);
90 	}
91 #ifdef DMALLOCDEBUG
92 	if (++MallocCount > MallocMax)
93 		MallocMax = MallocCount;
94 #endif
95 #ifdef USEGUARD
96 	res->ga_Magic = GAMAGIC;
97 #endif
98 	res->ga_Bytes = bytes;
99 #ifdef USEENDGUARD
100 	*((signed char *)res + bytes - 1) = -2;
101 #endif
102 
103 	return ((char *)res + MALLOCALIGN);
104 }
105 
106 void
107 Free(void *ptr, const char *file, int line)
108 {
109 	size_t bytes;
110 
111 	if (ptr != NULL) {
112 		Guard *res = (void *)((char *)ptr - MALLOCALIGN);
113 
114 		if (file == NULL)
115 			file = "unknown";
116 #ifdef USEGUARD
117 		if (res->ga_Magic == GAFREE) {
118 			printf("free: duplicate free @ %p from %s:%d\n",
119 			    ptr, file, line);
120 			return;
121 		}
122 		if (res->ga_Magic != GAMAGIC)
123 			panic("free: guard1 fail @ %p from %s:%d",
124 			    ptr, file, line);
125 		res->ga_Magic = GAFREE;
126 #endif
127 #ifdef USEENDGUARD
128 		if (*((signed char *)res + res->ga_Bytes - 1) == -1) {
129 			printf("free: duplicate2 free @ %p from %s:%d\n",
130 			    ptr, file, line);
131 			return;
132 		}
133 		if (*((signed char *)res + res->ga_Bytes - 1) != -2)
134 			panic("free: guard2 fail @ %p + %zu from %s:%d",
135 			    ptr, res->ga_Bytes - MALLOCALIGN, file, line);
136 		*((signed char *)res + res->ga_Bytes - 1) = -1;
137 #endif
138 
139 		bytes = res->ga_Bytes;
140 		zfree(&MallocPool, res, bytes);
141 #ifdef DMALLOCDEBUG
142 		--MallocCount;
143 #endif
144 	}
145 }
146 
147 
148 void *
149 Calloc(size_t n1, size_t n2, const char *file, int line)
150 {
151 	uintptr_t bytes = (uintptr_t)n1 * (uintptr_t)n2;
152 	void *res;
153 
154 	if ((res = Malloc(bytes, file, line)) != NULL) {
155 		bzero(res, bytes);
156 #ifdef DMALLOCDEBUG
157 		if (++MallocCount > MallocMax)
158 			MallocMax = MallocCount;
159 #endif
160 	}
161 	return (res);
162 }
163 
164 /*
165  * realloc() - I could be fancier here and free the old buffer before
166  *	       allocating the new one (saving potential fragmentation
167  *	       and potential buffer copies).  But I don't bother.
168  */
169 
170 void *
171 Realloc(void *ptr, size_t size, const char *file, int line)
172 {
173 	void *res;
174 	size_t old;
175 
176 	if ((res = Malloc(size, file, line)) != NULL) {
177 		if (ptr != NULL) {
178 			Guard *g = (Guard *)((char *)ptr - MALLOCALIGN);
179 
180 			old = g->ga_Bytes - MALLOCALIGN;
181 			if (old < size)
182 				bcopy(ptr, res, old);
183 			else
184 				bcopy(ptr, res, size);
185 			Free(ptr, file, line);
186 		} else {
187 #ifdef DMALLOCDEBUG
188 			if (++MallocCount > MallocMax)
189 				MallocMax = MallocCount;
190 #ifdef EXITSTATS
191 			if (DidAtExit == 0) {
192 				DidAtExit = 1;
193 				atexit(mallocstats);
194 			}
195 #endif
196 #endif
197 		}
198 	}
199 	return (res);
200 }
201 
202 void *
203 Reallocf(void *ptr, size_t size, const char *file, int line)
204 {
205 	void *res;
206 
207 	if ((res = Realloc(ptr, size, file, line)) == NULL)
208 		Free(ptr, file, line);
209 	return (res);
210 }
211 
212 #ifdef DMALLOCDEBUG
213 
214 void
215 mallocstats(void)
216 {
217 	printf("Active Allocations: %d/%d\n", MallocCount, MallocMax);
218 #ifdef ZALLOCDEBUG
219 	zallocstats(&MallocPool);
220 #endif
221 }
222 
223 #endif
224