xref: /freebsd/stand/libsa/zalloc_malloc.c (revision cfd6422a5217410fbd66f7a7a8a64d9d85e61229)
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