kern_malloc.c revision 1.143.4.2
1 /* $NetBSD: kern_malloc.c,v 1.143.4.2 2017/08/28 17:53:07 skrll 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 1.143.4.2 2017/08/28 17:53:07 skrll 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 if (size > (ULONG_MAX-PAGE_SIZE)) 109 allocsize = ULONG_MAX; /* this will fail later */ 110 else 111 allocsize = PAGE_SIZE + size; /* for page alignment */ 112 hdroffset = PAGE_SIZE - sizeof(struct malloc_header); 113 } else { 114 allocsize = sizeof(struct malloc_header) + size; 115 hdroffset = 0; 116 } 117 118 p = kmem_intr_alloc(allocsize, kmflags); 119 if (p == NULL) 120 return NULL; 121 122 if ((flags & M_ZERO) != 0) { 123 memset(p, 0, allocsize); 124 } 125 mh = (void *)((char *)p + hdroffset); 126 mh->mh_size = allocsize - hdroffset; 127 128 return mh + 1; 129 } 130 131 void 132 kern_free(void *addr) 133 { 134 struct malloc_header *mh; 135 136 mh = addr; 137 mh--; 138 139 if (mh->mh_size >= PAGE_SIZE + sizeof(struct malloc_header)) 140 kmem_intr_free((char *)addr - PAGE_SIZE, 141 mh->mh_size + PAGE_SIZE - sizeof(struct malloc_header)); 142 else 143 kmem_intr_free(mh, mh->mh_size); 144 } 145 146 void * 147 kern_realloc(void *curaddr, unsigned long newsize, int flags) 148 { 149 struct malloc_header *mh; 150 unsigned long cursize; 151 void *newaddr; 152 153 /* 154 * realloc() with a NULL pointer is the same as malloc(). 155 */ 156 if (curaddr == NULL) 157 return malloc(newsize, ksp, flags); 158 159 /* 160 * realloc() with zero size is the same as free(). 161 */ 162 if (newsize == 0) { 163 free(curaddr, ksp); 164 return NULL; 165 } 166 167 if ((flags & M_NOWAIT) == 0) { 168 ASSERT_SLEEPABLE(); 169 } 170 171 mh = curaddr; 172 mh--; 173 174 cursize = mh->mh_size - sizeof(struct malloc_header); 175 176 /* 177 * If we already actually have as much as they want, we're done. 178 */ 179 if (newsize <= cursize) 180 return curaddr; 181 182 /* 183 * Can't satisfy the allocation with the existing block. 184 * Allocate a new one and copy the data. 185 */ 186 newaddr = malloc(newsize, ksp, flags); 187 if (__predict_false(newaddr == NULL)) { 188 /* 189 * malloc() failed, because flags included M_NOWAIT. 190 * Return NULL to indicate that failure. The old 191 * pointer is still valid. 192 */ 193 return NULL; 194 } 195 memcpy(newaddr, curaddr, cursize); 196 197 /* 198 * We were successful: free the old allocation and return 199 * the new one. 200 */ 201 free(curaddr, ksp); 202 return newaddr; 203 } 204
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