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 #ifndef _STANDALONE 41 #include <sys/param.h> 42 #ifdef _KERNEL 43 #include <sys/systm.h> 44 #endif 45 #include <sys/queue.h> 46 #include <sys/_lock.h> 47 #include <sys/_mutex.h> 48 #include <machine/_limits.h> 49 50 #define MINALLOCSIZE UMA_SMALLEST_UNIT 51 52 /* 53 * Flags to memory allocation functions. 54 */ 55 #define M_NOWAIT 0x0001 /* do not block */ 56 #define M_WAITOK 0x0002 /* ok to block */ 57 #define M_ZERO 0x0100 /* bzero the allocation */ 58 #define M_NOVM 0x0200 /* don't ask VM for pages */ 59 #define M_USE_RESERVE 0x0400 /* can alloc out of reserve memory */ 60 #define M_NODUMP 0x0800 /* don't dump pages in this allocation */ 61 #define M_FIRSTFIT 0x1000 /* only for vmem, fast fit */ 62 #define M_BESTFIT 0x2000 /* only for vmem, low fragmentation */ 63 #define M_EXEC 0x4000 /* allocate executable space */ 64 #define M_NEXTFIT 0x8000 /* only for vmem, follow cursor */ 65 66 #define M_MAGIC 877983977 /* time when first defined :-) */ 67 68 /* 69 * Two malloc type structures are present: malloc_type, which is used by a 70 * type owner to declare the type, and malloc_type_internal, which holds 71 * malloc-owned statistics and other ABI-sensitive fields, such as the set of 72 * malloc statistics indexed by the compile-time MAXCPU constant. 73 * Applications should avoid introducing dependence on the allocator private 74 * data layout and size. 75 * 76 * The malloc_type ks_next field is protected by malloc_mtx. Other fields in 77 * malloc_type are static after initialization so unsynchronized. 78 * 79 * Statistics in malloc_type_stats are written only when holding a critical 80 * section and running on the CPU associated with the index into the stat 81 * array, but read lock-free resulting in possible (minor) races, which the 82 * monitoring app should take into account. 83 */ 84 struct malloc_type_stats { 85 uint64_t mts_memalloced; /* Bytes allocated on CPU. */ 86 uint64_t mts_memfreed; /* Bytes freed on CPU. */ 87 uint64_t mts_numallocs; /* Number of allocates on CPU. */ 88 uint64_t mts_numfrees; /* number of frees on CPU. */ 89 uint64_t mts_size; /* Bitmask of sizes allocated on CPU. */ 90 uint64_t _mts_reserved1; /* Reserved field. */ 91 uint64_t _mts_reserved2; /* Reserved field. */ 92 uint64_t _mts_reserved3; /* Reserved field. */ 93 }; 94 95 /* 96 * Index definitions for the mti_probes[] array. 97 */ 98 #define DTMALLOC_PROBE_MALLOC 0 99 #define DTMALLOC_PROBE_FREE 1 100 #define DTMALLOC_PROBE_MAX 2 101 102 struct malloc_type_internal { 103 uint32_t mti_probes[DTMALLOC_PROBE_MAX]; 104 /* DTrace probe ID array. */ 105 u_char mti_zone; 106 struct malloc_type_stats *mti_stats; 107 }; 108 109 /* 110 * Public data structure describing a malloc type. Private data is hung off 111 * of ks_handle to avoid encoding internal malloc(9) data structures in 112 * modules, which will statically allocate struct malloc_type. 113 */ 114 struct malloc_type { 115 struct malloc_type *ks_next; /* Next in global chain. */ 116 u_long ks_magic; /* Detect programmer error. */ 117 const char *ks_shortdesc; /* Printable type name. */ 118 void *ks_handle; /* Priv. data, was lo_class. */ 119 }; 120 121 /* 122 * Statistics structure headers for user space. The kern.malloc sysctl 123 * exposes a structure stream consisting of a stream header, then a series of 124 * malloc type headers and statistics structures (quantity maxcpus). For 125 * convenience, the kernel will provide the current value of maxcpus at the 126 * head of the stream. 127 */ 128 #define MALLOC_TYPE_STREAM_VERSION 0x00000001 129 struct malloc_type_stream_header { 130 uint32_t mtsh_version; /* Stream format version. */ 131 uint32_t mtsh_maxcpus; /* Value of MAXCPU for stream. */ 132 uint32_t mtsh_count; /* Number of records. */ 133 uint32_t _mtsh_pad; /* Pad/reserved field. */ 134 }; 135 136 #define MALLOC_MAX_NAME 32 137 struct malloc_type_header { 138 char mth_name[MALLOC_MAX_NAME]; 139 }; 140 141 #ifdef _KERNEL 142 #define MALLOC_DEFINE(type, shortdesc, longdesc) \ 143 struct malloc_type type[1] = { \ 144 { NULL, M_MAGIC, shortdesc, NULL } \ 145 }; \ 146 SYSINIT(type##_init, SI_SUB_KMEM, SI_ORDER_THIRD, malloc_init, \ 147 type); \ 148 SYSUNINIT(type##_uninit, SI_SUB_KMEM, SI_ORDER_ANY, \ 149 malloc_uninit, type) 150 151 #define MALLOC_DECLARE(type) \ 152 extern struct malloc_type type[1] 153 154 MALLOC_DECLARE(M_CACHE); 155 MALLOC_DECLARE(M_DEVBUF); 156 MALLOC_DECLARE(M_TEMP); 157 158 /* 159 * XXX this should be declared in <sys/uio.h>, but that tends to fail 160 * because <sys/uio.h> is included in a header before the source file 161 * has a chance to include <sys/malloc.h> to get MALLOC_DECLARE() defined. 162 */ 163 MALLOC_DECLARE(M_IOV); 164 165 struct domainset; 166 extern struct mtx malloc_mtx; 167 168 /* 169 * Function type used when iterating over the list of malloc types. 170 */ 171 typedef void malloc_type_list_func_t(struct malloc_type *, void *); 172 173 void contigfree(void *addr, unsigned long size, struct malloc_type *type); 174 void *contigmalloc(unsigned long size, struct malloc_type *type, int flags, 175 vm_paddr_t low, vm_paddr_t high, unsigned long alignment, 176 vm_paddr_t boundary) __malloc_like __result_use_check 177 __alloc_size(1) __alloc_align(6); 178 void *contigmalloc_domainset(unsigned long size, struct malloc_type *type, 179 struct domainset *ds, int flags, vm_paddr_t low, vm_paddr_t high, 180 unsigned long alignment, vm_paddr_t boundary) 181 __malloc_like __result_use_check __alloc_size(1) __alloc_align(7); 182 void free(void *addr, struct malloc_type *type); 183 void zfree(void *addr, struct malloc_type *type); 184 void *malloc(size_t size, struct malloc_type *type, int flags) __malloc_like 185 __result_use_check __alloc_size(1); 186 /* 187 * Try to optimize malloc(..., ..., M_ZERO) allocations by doing zeroing in 188 * place if the size is known at compilation time. 189 * 190 * Passing the flag down requires malloc to blindly zero the entire object. 191 * In practice a lot of the zeroing can be avoided if most of the object 192 * gets explicitly initialized after the allocation. Letting the compiler 193 * zero in place gives it the opportunity to take advantage of this state. 194 * 195 * Note that the operation is only applicable if both flags and size are 196 * known at compilation time. If M_ZERO is passed but M_WAITOK is not, the 197 * allocation can fail and a NULL check is needed. However, if M_WAITOK is 198 * passed we know the allocation must succeed and the check can be elided. 199 * 200 * _malloc_item = malloc(_size, type, (flags) &~ M_ZERO); 201 * if (((flags) & M_WAITOK) != 0 || _malloc_item != NULL) 202 * bzero(_malloc_item, _size); 203 * 204 * If the flag is set, the compiler knows the left side is always true, 205 * therefore the entire statement is true and the callsite is: 206 * 207 * _malloc_item = malloc(_size, type, (flags) &~ M_ZERO); 208 * bzero(_malloc_item, _size); 209 * 210 * If the flag is not set, the compiler knows the left size is always false 211 * and the NULL check is needed, therefore the callsite is: 212 * 213 * _malloc_item = malloc(_size, type, (flags) &~ M_ZERO); 214 * if (_malloc_item != NULL) 215 * bzero(_malloc_item, _size); 216 * 217 * The implementation is a macro because of what appears to be a clang 6 bug: 218 * an inline function variant ended up being compiled to a mere malloc call 219 * regardless of argument. gcc generates expected code (like the above). 220 */ 221 #define malloc(size, type, flags) ({ \ 222 void *_malloc_item; \ 223 size_t _size = (size); \ 224 if (__builtin_constant_p(size) && __builtin_constant_p(flags) &&\ 225 ((flags) & M_ZERO) != 0) { \ 226 _malloc_item = malloc(_size, type, (flags) &~ M_ZERO); \ 227 if (((flags) & M_WAITOK) != 0 || \ 228 __predict_true(_malloc_item != NULL)) \ 229 bzero(_malloc_item, _size); \ 230 } else { \ 231 _malloc_item = malloc(_size, type, flags); \ 232 } \ 233 _malloc_item; \ 234 }) 235 236 void *malloc_domainset(size_t size, struct malloc_type *type, 237 struct domainset *ds, int flags) __malloc_like __result_use_check 238 __alloc_size(1); 239 void *mallocarray(size_t nmemb, size_t size, struct malloc_type *type, 240 int flags) __malloc_like __result_use_check 241 __alloc_size2(1, 2); 242 void malloc_init(void *); 243 int malloc_last_fail(void); 244 void malloc_type_allocated(struct malloc_type *type, unsigned long size); 245 void malloc_type_freed(struct malloc_type *type, unsigned long size); 246 void malloc_type_list(malloc_type_list_func_t *, void *); 247 void malloc_uninit(void *); 248 size_t malloc_usable_size(const void *); 249 void *realloc(void *addr, size_t size, struct malloc_type *type, int flags) 250 __result_use_check __alloc_size(2); 251 void *reallocf(void *addr, size_t size, struct malloc_type *type, int flags) 252 __result_use_check __alloc_size(2); 253 254 struct malloc_type *malloc_desc2type(const char *desc); 255 256 /* 257 * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX 258 * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW 259 */ 260 #define MUL_NO_OVERFLOW (1UL << (sizeof(size_t) * 8 / 2)) 261 static inline bool 262 WOULD_OVERFLOW(size_t nmemb, size_t size) 263 { 264 265 return ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) && 266 nmemb > 0 && __SIZE_T_MAX / nmemb < size); 267 } 268 #undef MUL_NO_OVERFLOW 269 #endif /* _KERNEL */ 270 271 #else 272 /* 273 * The native stand malloc / free interface we're mapping to 274 */ 275 extern void Free(void *p, const char *file, int line); 276 extern void *Malloc(size_t bytes, const char *file, int line); 277 278 /* 279 * Minimal standalone malloc implementation / environment. None of the 280 * flags mean anything and there's no need declare malloc types. 281 * Define the simple alloc / free routines in terms of Malloc and 282 * Free. None of the kernel features that this stuff disables are needed. 283 * 284 * XXX we are setting ourselves up for a potential crash if we can't allocate 285 * memory for a M_WAITOK call. 286 */ 287 #define M_WAITOK 0 288 #define M_ZERO 0 289 #define M_NOWAIT 0 290 #define MALLOC_DECLARE(x) 291 292 #define kmem_zalloc(size, flags) Malloc((size), __FILE__, __LINE__) 293 #define kmem_free(p, size) Free(p, __FILE__, __LINE__) 294 295 /* 296 * ZFS mem.h define that's the OpenZFS porting layer way of saying 297 * M_WAITOK. Given the above, it will also be a nop. 298 */ 299 #define KM_SLEEP M_WAITOK 300 #endif /* _STANDALONE */ 301 #endif /* !_SYS_MALLOC_H_ */ 302