kern_malloc.c revision 1.146.2.1
1 /* $NetBSD: kern_malloc.c,v 1.146.2.1 2018/09/06 06:56:41 pgoyette 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 1.146.2.1 2018/09/06 06:56:41 pgoyette Exp $"); 74 75 #include <sys/param.h> 76 #include <sys/malloc.h> 77 #include <sys/kmem.h> 78 #include <sys/asan.h> 79 80 /* 81 * Built-in malloc types. Note: ought to be removed. 82 */ 83 MALLOC_DEFINE(M_DEVBUF, "devbuf", "device driver memory"); 84 MALLOC_DEFINE(M_DMAMAP, "DMA map", "bus_dma(9) structures"); 85 MALLOC_DEFINE(M_FREE, "free", "should be on free list"); 86 MALLOC_DEFINE(M_TEMP, "temp", "misc. temporary data buffers"); 87 MALLOC_DEFINE(M_RTABLE, "routetbl", "routing tables"); 88 MALLOC_DEFINE(M_FTABLE, "fragtbl", "fragment reassembly header"); 89 MALLOC_DEFINE(M_UFSMNT, "UFS mount", "UFS mount structure"); 90 MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure"); 91 MALLOC_DEFINE(M_MRTABLE, "mrt", "multicast routing tables"); 92 93 /* 94 * Header contains total size, including the header itself. 95 */ 96 struct malloc_header { 97 size_t mh_size; 98 #ifdef KASAN 99 size_t mh_rqsz; 100 #endif 101 } __aligned(ALIGNBYTES + 1); 102 103 void * 104 kern_malloc(unsigned long size, int flags) 105 { 106 const int kmflags = (flags & M_NOWAIT) ? KM_NOSLEEP : KM_SLEEP; 107 #ifdef KASAN 108 const size_t origsize = size; 109 #endif 110 size_t allocsize, hdroffset; 111 struct malloc_header *mh; 112 void *p; 113 114 kasan_add_redzone(&size); 115 116 if (size >= PAGE_SIZE) { 117 if (size > (ULONG_MAX-PAGE_SIZE)) 118 allocsize = ULONG_MAX; /* this will fail later */ 119 else 120 allocsize = PAGE_SIZE + size; /* for page alignment */ 121 hdroffset = PAGE_SIZE - sizeof(struct malloc_header); 122 } else { 123 allocsize = sizeof(struct malloc_header) + size; 124 hdroffset = 0; 125 } 126 127 p = kmem_intr_alloc(allocsize, kmflags); 128 if (p == NULL) 129 return NULL; 130 131 if ((flags & M_ZERO) != 0) { 132 memset(p, 0, allocsize); 133 } 134 mh = (void *)((char *)p + hdroffset); 135 mh->mh_size = allocsize - hdroffset; 136 #ifdef KASAN 137 mh->mh_rqsz = origsize; 138 #endif 139 mh++; 140 141 kasan_alloc(mh, origsize, size); 142 143 return mh; 144 } 145 146 void 147 kern_free(void *addr) 148 { 149 struct malloc_header *mh; 150 151 mh = addr; 152 mh--; 153 154 kasan_free(addr, mh->mh_size); 155 156 if (mh->mh_size >= PAGE_SIZE + sizeof(struct malloc_header)) 157 kmem_intr_free((char *)addr - PAGE_SIZE, 158 mh->mh_size + PAGE_SIZE - sizeof(struct malloc_header)); 159 else 160 kmem_intr_free(mh, mh->mh_size); 161 } 162 163 void * 164 kern_realloc(void *curaddr, unsigned long newsize, int flags) 165 { 166 struct malloc_header *mh; 167 unsigned long cursize; 168 void *newaddr; 169 170 /* 171 * realloc() with a NULL pointer is the same as malloc(). 172 */ 173 if (curaddr == NULL) 174 return malloc(newsize, ksp, flags); 175 176 /* 177 * realloc() with zero size is the same as free(). 178 */ 179 if (newsize == 0) { 180 free(curaddr, ksp); 181 return NULL; 182 } 183 184 if ((flags & M_NOWAIT) == 0) { 185 ASSERT_SLEEPABLE(); 186 } 187 188 mh = curaddr; 189 mh--; 190 191 #ifdef KASAN 192 cursize = mh->mh_rqsz; 193 #else 194 cursize = mh->mh_size - sizeof(struct malloc_header); 195 #endif 196 197 /* 198 * If we already actually have as much as they want, we're done. 199 */ 200 if (newsize <= cursize) 201 return curaddr; 202 203 /* 204 * Can't satisfy the allocation with the existing block. 205 * Allocate a new one and copy the data. 206 */ 207 newaddr = malloc(newsize, ksp, flags); 208 if (__predict_false(newaddr == NULL)) { 209 /* 210 * malloc() failed, because flags included M_NOWAIT. 211 * Return NULL to indicate that failure. The old 212 * pointer is still valid. 213 */ 214 return NULL; 215 } 216 memcpy(newaddr, curaddr, cursize); 217 218 /* 219 * We were successful: free the old allocation and return 220 * the new one. 221 */ 222 free(curaddr, ksp); 223 return newaddr; 224 } 225
Indexes created Sat Sep 20 22:09:52 GMT 2025