1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1987, 1993 5 * The Regents of the University of California. 6 * Copyright (c) 2005, 2009 Robert N. M. Watson 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)malloc.h 8.5 (Berkeley) 5/3/95 34 * $FreeBSD$ 35 */ 36 37 #ifndef _SYS_MALLOC_H_ 38 #define _SYS_MALLOC_H_ 39 40 #include <sys/param.h> 41 #ifdef _KERNEL 42 #include <sys/systm.h> 43 #endif 44 #include <sys/queue.h> 45 #include <sys/_lock.h> 46 #include <sys/_mutex.h> 47 #include <machine/_limits.h> 48 49 #define MINALLOCSIZE UMA_SMALLEST_UNIT 50 51 /* 52 * Flags to memory allocation functions. 53 */ 54 #define M_NOWAIT 0x0001 /* do not block */ 55 #define M_WAITOK 0x0002 /* ok to block */ 56 #define M_ZERO 0x0100 /* bzero the allocation */ 57 #define M_NOVM 0x0200 /* don't ask VM for pages */ 58 #define M_USE_RESERVE 0x0400 /* can alloc out of reserve memory */ 59 #define M_NODUMP 0x0800 /* don't dump pages in this allocation */ 60 #define M_FIRSTFIT 0x1000 /* Only for vmem, fast fit. */ 61 #define M_BESTFIT 0x2000 /* Only for vmem, low fragmentation. */ 62 #define M_EXEC 0x4000 /* allocate executable space. */ 63 64 #define M_MAGIC 877983977 /* time when first defined :-) */ 65 66 /* 67 * Two malloc type structures are present: malloc_type, which is used by a 68 * type owner to declare the type, and malloc_type_internal, which holds 69 * malloc-owned statistics and other ABI-sensitive fields, such as the set of 70 * malloc statistics indexed by the compile-time MAXCPU constant. 71 * Applications should avoid introducing dependence on the allocator private 72 * data layout and size. 73 * 74 * The malloc_type ks_next field is protected by malloc_mtx. Other fields in 75 * malloc_type are static after initialization so unsynchronized. 76 * 77 * Statistics in malloc_type_stats are written only when holding a critical 78 * section and running on the CPU associated with the index into the stat 79 * array, but read lock-free resulting in possible (minor) races, which the 80 * monitoring app should take into account. 81 */ 82 struct malloc_type_stats { 83 uint64_t mts_memalloced; /* Bytes allocated on CPU. */ 84 uint64_t mts_memfreed; /* Bytes freed on CPU. */ 85 uint64_t mts_numallocs; /* Number of allocates on CPU. */ 86 uint64_t mts_numfrees; /* number of frees on CPU. */ 87 uint64_t mts_size; /* Bitmask of sizes allocated on CPU. */ 88 uint64_t _mts_reserved1; /* Reserved field. */ 89 uint64_t _mts_reserved2; /* Reserved field. */ 90 uint64_t _mts_reserved3; /* Reserved field. */ 91 }; 92 93 /* 94 * Index definitions for the mti_probes[] array. 95 */ 96 #define DTMALLOC_PROBE_MALLOC 0 97 #define DTMALLOC_PROBE_FREE 1 98 #define DTMALLOC_PROBE_MAX 2 99 100 struct malloc_type_internal { 101 uint32_t mti_probes[DTMALLOC_PROBE_MAX]; 102 /* DTrace probe ID array. */ 103 u_char mti_zone; 104 struct malloc_type_stats *mti_stats; 105 }; 106 107 /* 108 * Public data structure describing a malloc type. Private data is hung off 109 * of ks_handle to avoid encoding internal malloc(9) data structures in 110 * modules, which will statically allocate struct malloc_type. 111 */ 112 struct malloc_type { 113 struct malloc_type *ks_next; /* Next in global chain. */ 114 u_long ks_magic; /* Detect programmer error. */ 115 const char *ks_shortdesc; /* Printable type name. */ 116 void *ks_handle; /* Priv. data, was lo_class. */ 117 }; 118 119 /* 120 * Statistics structure headers for user space. The kern.malloc sysctl 121 * exposes a structure stream consisting of a stream header, then a series of 122 * malloc type headers and statistics structures (quantity maxcpus). For 123 * convenience, the kernel will provide the current value of maxcpus at the 124 * head of the stream. 125 */ 126 #define MALLOC_TYPE_STREAM_VERSION 0x00000001 127 struct malloc_type_stream_header { 128 uint32_t mtsh_version; /* Stream format version. */ 129 uint32_t mtsh_maxcpus; /* Value of MAXCPU for stream. */ 130 uint32_t mtsh_count; /* Number of records. */ 131 uint32_t _mtsh_pad; /* Pad/reserved field. */ 132 }; 133 134 #define MALLOC_MAX_NAME 32 135 struct malloc_type_header { 136 char mth_name[MALLOC_MAX_NAME]; 137 }; 138 139 #ifdef _KERNEL 140 #define MALLOC_DEFINE(type, shortdesc, longdesc) \ 141 struct malloc_type type[1] = { \ 142 { NULL, M_MAGIC, shortdesc, NULL } \ 143 }; \ 144 SYSINIT(type##_init, SI_SUB_KMEM, SI_ORDER_THIRD, malloc_init, \ 145 type); \ 146 SYSUNINIT(type##_uninit, SI_SUB_KMEM, SI_ORDER_ANY, \ 147 malloc_uninit, type) 148 149 #define MALLOC_DECLARE(type) \ 150 extern struct malloc_type type[1] 151 152 MALLOC_DECLARE(M_CACHE); 153 MALLOC_DECLARE(M_DEVBUF); 154 MALLOC_DECLARE(M_TEMP); 155 156 /* 157 * XXX this should be declared in <sys/uio.h>, but that tends to fail 158 * because <sys/uio.h> is included in a header before the source file 159 * has a chance to include <sys/malloc.h> to get MALLOC_DECLARE() defined. 160 */ 161 MALLOC_DECLARE(M_IOV); 162 163 struct domainset; 164 extern struct mtx malloc_mtx; 165 166 /* 167 * Function type used when iterating over the list of malloc types. 168 */ 169 typedef void malloc_type_list_func_t(struct malloc_type *, void *); 170 171 void contigfree(void *addr, unsigned long size, struct malloc_type *type); 172 void *contigmalloc(unsigned long size, struct malloc_type *type, int flags, 173 vm_paddr_t low, vm_paddr_t high, unsigned long alignment, 174 vm_paddr_t boundary) __malloc_like __result_use_check 175 __alloc_size(1) __alloc_align(6); 176 void *contigmalloc_domainset(unsigned long size, struct malloc_type *type, 177 struct domainset *ds, int flags, vm_paddr_t low, vm_paddr_t high, 178 unsigned long alignment, vm_paddr_t boundary) 179 __malloc_like __result_use_check __alloc_size(1) __alloc_align(6); 180 void free(void *addr, struct malloc_type *type); 181 void free_domain(void *addr, struct malloc_type *type); 182 void *malloc(size_t size, struct malloc_type *type, int flags) __malloc_like 183 __result_use_check __alloc_size(1); 184 /* 185 * Try to optimize malloc(..., ..., M_ZERO) allocations by doing zeroing in 186 * place if the size is known at compilation time. 187 * 188 * Passing the flag down requires malloc to blindly zero the entire object. 189 * In practice a lot of the zeroing can be avoided if most of the object 190 * gets explicitly initialized after the allocation. Letting the compiler 191 * zero in place gives it the opportunity to take advantage of this state. 192 * 193 * Note that the operation is only applicable if both flags and size are 194 * known at compilation time. If M_ZERO is passed but M_WAITOK is not, the 195 * allocation can fail and a NULL check is needed. However, if M_WAITOK is 196 * passed we know the allocation must succeed and the check can be elided. 197 * 198 * _malloc_item = malloc(_size, type, (flags) &~ M_ZERO); 199 * if (((flags) & M_WAITOK) != 0 || _malloc_item != NULL) 200 * bzero(_malloc_item, _size); 201 * 202 * If the flag is set, the compiler knows the left side is always true, 203 * therefore the entire statement is true and the callsite is: 204 * 205 * _malloc_item = malloc(_size, type, (flags) &~ M_ZERO); 206 * bzero(_malloc_item, _size); 207 * 208 * If the flag is not set, the compiler knows the left size is always false 209 * and the NULL check is needed, therefore the callsite is: 210 * 211 * _malloc_item = malloc(_size, type, (flags) &~ M_ZERO); 212 * if (_malloc_item != NULL) 213 * bzero(_malloc_item, _size); 214 * 215 * The implementation is a macro because of what appears to be a clang 6 bug: 216 * an inline function variant ended up being compiled to a mere malloc call 217 * regardless of argument. gcc generates expected code (like the above). 218 */ 219 #define malloc(size, type, flags) ({ \ 220 void *_malloc_item; \ 221 size_t _size = (size); \ 222 if (__builtin_constant_p(size) && __builtin_constant_p(flags) &&\ 223 ((flags) & M_ZERO) != 0) { \ 224 _malloc_item = malloc(_size, type, (flags) &~ M_ZERO); \ 225 if (((flags) & M_WAITOK) != 0 || \ 226 __predict_true(_malloc_item != NULL)) \ 227 bzero(_malloc_item, _size); \ 228 } else { \ 229 _malloc_item = malloc(_size, type, flags); \ 230 } \ 231 _malloc_item; \ 232 }) 233 234 void *malloc_domainset(size_t size, struct malloc_type *type, 235 struct domainset *ds, int flags) __malloc_like __result_use_check 236 __alloc_size(1); 237 void *mallocarray(size_t nmemb, size_t size, struct malloc_type *type, 238 int flags) __malloc_like __result_use_check 239 __alloc_size2(1, 2); 240 void malloc_init(void *); 241 int malloc_last_fail(void); 242 void malloc_type_allocated(struct malloc_type *type, unsigned long size); 243 void malloc_type_freed(struct malloc_type *type, unsigned long size); 244 void malloc_type_list(malloc_type_list_func_t *, void *); 245 void malloc_uninit(void *); 246 void *realloc(void *addr, size_t size, struct malloc_type *type, int flags) 247 __result_use_check __alloc_size(2); 248 void *reallocf(void *addr, size_t size, struct malloc_type *type, int flags) 249 __result_use_check __alloc_size(2); 250 251 struct malloc_type *malloc_desc2type(const char *desc); 252 253 /* 254 * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX 255 * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW 256 */ 257 #define MUL_NO_OVERFLOW (1UL << (sizeof(size_t) * 8 / 2)) 258 static inline bool 259 WOULD_OVERFLOW(size_t nmemb, size_t size) 260 { 261 262 return ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) && 263 nmemb > 0 && __SIZE_T_MAX / nmemb < size); 264 } 265 #undef MUL_NO_OVERFLOW 266 #endif /* _KERNEL */ 267 268 #endif /* !_SYS_MALLOC_H_ */ 269