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kern_malloc.c revision 1.133.6.2
      1 /*	$NetBSD: kern_malloc.c,v 1.133.6.2 2012/04/29 23:05:04 mrg 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 1.133.6.2 2012/04/29 23:05:04 mrg Exp $");
     74 
     75 #include <sys/param.h>
     76 #include <sys/malloc.h>
     77 #include <sys/kmem.h>
     78 
     79 #include <uvm/uvm_extern.h>
     80 
     81 /*
     82  * Built-in malloc types.  Note: ought to be removed.
     83  */
     84 MALLOC_DEFINE(M_DEVBUF, "devbuf", "device driver memory");
     85 MALLOC_DEFINE(M_DMAMAP, "DMA map", "bus_dma(9) structures");
     86 MALLOC_DEFINE(M_FREE, "free", "should be on free list");
     87 MALLOC_DEFINE(M_PCB, "pcb", "protocol control block");
     88 MALLOC_DEFINE(M_TEMP, "temp", "misc. temporary data buffers");
     89 MALLOC_DEFINE(M_RTABLE, "routetbl", "routing tables");
     90 MALLOC_DEFINE(M_FTABLE, "fragtbl", "fragment reassembly header");
     91 MALLOC_DEFINE(M_UFSMNT, "UFS mount", "UFS mount structure");
     92 MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure");
     93 MALLOC_DEFINE(M_IPMOPTS, "ip_moptions", "internet multicast options");
     94 MALLOC_DEFINE(M_IPMADDR, "in_multi", "internet multicast address");
     95 MALLOC_DEFINE(M_MRTABLE, "mrt", "multicast routing tables");
     96 MALLOC_DEFINE(M_BWMETER, "bwmeter", "multicast upcall bw meters");
     97 
     98 /*
     99  * Header contains total size, including the header itself.
    100  */
    101 struct malloc_header {
    102 	size_t		mh_size;
    103 } __aligned(ALIGNBYTES + 1);
    104 
    105 void *
    106 kern_malloc(unsigned long size, int flags)
    107 {
    108 	const int kmflags = (flags & M_NOWAIT) ? KM_NOSLEEP : KM_SLEEP;
    109 	size_t allocsize, hdroffset;
    110 	struct malloc_header *mh;
    111 	void *p;
    112 
    113 	if (size >= PAGE_SIZE) {
    114 		allocsize = PAGE_SIZE + size; /* for page alignment */
    115 		hdroffset = PAGE_SIZE - sizeof(struct malloc_header);
    116 	} else {
    117 		allocsize = sizeof(struct malloc_header) + size;
    118 		hdroffset = 0;
    119 	}
    120 
    121 	p = kmem_intr_alloc(allocsize, kmflags);
    122 	if (p == NULL)
    123 		return NULL;
    124 
    125 	if ((flags & M_ZERO) != 0) {
    126 		memset(p, 0, allocsize);
    127 	}
    128 	mh = (void *)((char *)p + hdroffset);
    129 	mh->mh_size = allocsize - hdroffset;
    130 
    131 	return mh + 1;
    132 }
    133 
    134 void
    135 kern_free(void *addr)
    136 {
    137 	struct malloc_header *mh;
    138 
    139 	mh = addr;
    140 	mh--;
    141 
    142 	if (mh->mh_size >= PAGE_SIZE + sizeof(struct malloc_header))
    143 		kmem_intr_free((char *)addr - PAGE_SIZE,
    144 		    mh->mh_size + PAGE_SIZE - sizeof(struct malloc_header));
    145 	else
    146 		kmem_intr_free(mh, mh->mh_size);
    147 }
    148 
    149 void *
    150 kern_realloc(void *curaddr, unsigned long newsize, int flags)
    151 {
    152 	struct malloc_header *mh;
    153 	unsigned long cursize;
    154 	void *newaddr;
    155 
    156 	/*
    157 	 * realloc() with a NULL pointer is the same as malloc().
    158 	 */
    159 	if (curaddr == NULL)
    160 		return malloc(newsize, ksp, flags);
    161 
    162 	/*
    163 	 * realloc() with zero size is the same as free().
    164 	 */
    165 	if (newsize == 0) {
    166 		free(curaddr, ksp);
    167 		return NULL;
    168 	}
    169 
    170 	if ((flags & M_NOWAIT) == 0) {
    171 		ASSERT_SLEEPABLE();
    172 	}
    173 
    174 	mh = curaddr;
    175 	mh--;
    176 
    177 	cursize = mh->mh_size - sizeof(struct malloc_header);
    178 
    179 	/*
    180 	 * If we already actually have as much as they want, we're done.
    181 	 */
    182 	if (newsize <= cursize)
    183 		return curaddr;
    184 
    185 	/*
    186 	 * Can't satisfy the allocation with the existing block.
    187 	 * Allocate a new one and copy the data.
    188 	 */
    189 	newaddr = malloc(newsize, ksp, flags);
    190 	if (__predict_false(newaddr == NULL)) {
    191 		/*
    192 		 * malloc() failed, because flags included M_NOWAIT.
    193 		 * Return NULL to indicate that failure.  The old
    194 		 * pointer is still valid.
    195 		 */
    196 		return NULL;
    197 	}
    198 	memcpy(newaddr, curaddr, cursize);
    199 
    200 	/*
    201 	 * We were successful: free the old allocation and return
    202 	 * the new one.
    203 	 */
    204 	free(curaddr, ksp);
    205 	return newaddr;
    206 }
    207 
    208 void
    209 malloc_type_attach(struct malloc_type *type)
    210 {
    211 	KASSERT(type->ks_magic == M_MAGIC);
    212 }
    213 
    214 void
    215 malloc_type_detach(struct malloc_type *type)
    216 {
    217 	KASSERT(type->ks_magic == M_MAGIC);
    218 }
    219 
    220 /*
    221  * Initialize the kernel memory allocator
    222  */
    223 void
    224 kmeminit(void)
    225 {
    226 	__link_set_decl(malloc_types, struct malloc_type);
    227 	struct malloc_type * const *ksp;
    228 
    229 	/* Attach all of the statically-linked malloc types. */
    230 	__link_set_foreach(ksp, malloc_types)
    231 		malloc_type_attach(*ksp);
    232 }
    233