xref: /netbsd-src/sys/kern/kern_malloc.c (revision 946379e7b37692fc43f68eb0d1c10daa0a7f3b6c)
1 /*	$NetBSD: kern_malloc.c,v 1.145 2015/02/06 18:21:29 maxv Exp $	*/
2 
3 /*
4  * Copyright (c) 1987, 1991, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following 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  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	@(#)kern_malloc.c	8.4 (Berkeley) 5/20/95
32  */
33 
34 /*
35  * Copyright (c) 1996 Christopher G. Demetriou.  All rights reserved.
36  *
37  * Redistribution and use in source and binary forms, with or without
38  * modification, are permitted provided that the following conditions
39  * are met:
40  * 1. Redistributions of source code must retain the above copyright
41  *    notice, this list of conditions and the following disclaimer.
42  * 2. Redistributions in binary form must reproduce the above copyright
43  *    notice, this list of conditions and the following disclaimer in the
44  *    documentation and/or other materials provided with the distribution.
45  * 3. All advertising materials mentioning features or use of this software
46  *    must display the following acknowledgement:
47  *	This product includes software developed by the University of
48  *	California, Berkeley and its contributors.
49  * 4. Neither the name of the University nor the names of its contributors
50  *    may be used to endorse or promote products derived from this software
51  *    without specific prior written permission.
52  *
53  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
54  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
55  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
56  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
57  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
58  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
59  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
60  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
61  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
62  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
63  * SUCH DAMAGE.
64  *
65  *	@(#)kern_malloc.c	8.4 (Berkeley) 5/20/95
66  */
67 
68 /*
69  * Wrapper interface for obsolete malloc(9).
70  */
71 
72 #include <sys/cdefs.h>
73 __KERNEL_RCSID(0, "$NetBSD: kern_malloc.c,v 1.145 2015/02/06 18:21:29 maxv Exp $");
74 
75 #include <sys/param.h>
76 #include <sys/malloc.h>
77 #include <sys/kmem.h>
78 
79 /*
80  * Built-in malloc types.  Note: ought to be removed.
81  */
82 MALLOC_DEFINE(M_DEVBUF, "devbuf", "device driver memory");
83 MALLOC_DEFINE(M_DMAMAP, "DMA map", "bus_dma(9) structures");
84 MALLOC_DEFINE(M_FREE, "free", "should be on free list");
85 MALLOC_DEFINE(M_TEMP, "temp", "misc. temporary data buffers");
86 MALLOC_DEFINE(M_RTABLE, "routetbl", "routing tables");
87 MALLOC_DEFINE(M_FTABLE, "fragtbl", "fragment reassembly header");
88 MALLOC_DEFINE(M_UFSMNT, "UFS mount", "UFS mount structure");
89 MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure");
90 MALLOC_DEFINE(M_MRTABLE, "mrt", "multicast routing tables");
91 
92 /*
93  * Header contains total size, including the header itself.
94  */
95 struct malloc_header {
96 	size_t		mh_size;
97 } __aligned(ALIGNBYTES + 1);
98 
99 void *
100 kern_malloc(unsigned long size, int flags)
101 {
102 	const int kmflags = (flags & M_NOWAIT) ? KM_NOSLEEP : KM_SLEEP;
103 	size_t allocsize, hdroffset;
104 	struct malloc_header *mh;
105 	void *p;
106 
107 	if (size >= PAGE_SIZE) {
108 		allocsize = PAGE_SIZE + size; /* for page alignment */
109 		hdroffset = PAGE_SIZE - sizeof(struct malloc_header);
110 	} else {
111 		allocsize = sizeof(struct malloc_header) + size;
112 		hdroffset = 0;
113 	}
114 
115 	p = kmem_intr_alloc(allocsize, kmflags);
116 	if (p == NULL)
117 		return NULL;
118 
119 	if ((flags & M_ZERO) != 0) {
120 		memset(p, 0, allocsize);
121 	}
122 	mh = (void *)((char *)p + hdroffset);
123 	mh->mh_size = allocsize - hdroffset;
124 
125 	return mh + 1;
126 }
127 
128 void
129 kern_free(void *addr)
130 {
131 	struct malloc_header *mh;
132 
133 	mh = addr;
134 	mh--;
135 
136 	if (mh->mh_size >= PAGE_SIZE + sizeof(struct malloc_header))
137 		kmem_intr_free((char *)addr - PAGE_SIZE,
138 		    mh->mh_size + PAGE_SIZE - sizeof(struct malloc_header));
139 	else
140 		kmem_intr_free(mh, mh->mh_size);
141 }
142 
143 void *
144 kern_realloc(void *curaddr, unsigned long newsize, int flags)
145 {
146 	struct malloc_header *mh;
147 	unsigned long cursize;
148 	void *newaddr;
149 
150 	/*
151 	 * realloc() with a NULL pointer is the same as malloc().
152 	 */
153 	if (curaddr == NULL)
154 		return malloc(newsize, ksp, flags);
155 
156 	/*
157 	 * realloc() with zero size is the same as free().
158 	 */
159 	if (newsize == 0) {
160 		free(curaddr, ksp);
161 		return NULL;
162 	}
163 
164 	if ((flags & M_NOWAIT) == 0) {
165 		ASSERT_SLEEPABLE();
166 	}
167 
168 	mh = curaddr;
169 	mh--;
170 
171 	cursize = mh->mh_size - sizeof(struct malloc_header);
172 
173 	/*
174 	 * If we already actually have as much as they want, we're done.
175 	 */
176 	if (newsize <= cursize)
177 		return curaddr;
178 
179 	/*
180 	 * Can't satisfy the allocation with the existing block.
181 	 * Allocate a new one and copy the data.
182 	 */
183 	newaddr = malloc(newsize, ksp, flags);
184 	if (__predict_false(newaddr == NULL)) {
185 		/*
186 		 * malloc() failed, because flags included M_NOWAIT.
187 		 * Return NULL to indicate that failure.  The old
188 		 * pointer is still valid.
189 		 */
190 		return NULL;
191 	}
192 	memcpy(newaddr, curaddr, cursize);
193 
194 	/*
195 	 * We were successful: free the old allocation and return
196 	 * the new one.
197 	 */
198 	free(curaddr, ksp);
199 	return newaddr;
200 }
201