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_VERSION 2020110501 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 _Static_assert(sizeof(struct malloc_type_stats) == 64, 96 "allocations come from pcpu_zone_64"); 97 98 /* 99 * Index definitions for the mti_probes[] array. 100 */ 101 #define DTMALLOC_PROBE_MALLOC 0 102 #define DTMALLOC_PROBE_FREE 1 103 #define DTMALLOC_PROBE_MAX 2 104 105 struct malloc_type_internal { 106 uint32_t mti_probes[DTMALLOC_PROBE_MAX]; 107 /* DTrace probe ID array. */ 108 u_char mti_zone; 109 struct malloc_type_stats *mti_stats; 110 u_long mti_spare[8]; 111 }; 112 113 /* 114 * Public data structure describing a malloc type. 115 */ 116 struct malloc_type { 117 struct malloc_type *ks_next; /* Next in global chain. */ 118 u_long ks_version; /* Detect programmer error. */ 119 const char *ks_shortdesc; /* Printable type name. */ 120 struct malloc_type_internal ks_mti; 121 }; 122 123 /* 124 * Statistics structure headers for user space. The kern.malloc sysctl 125 * exposes a structure stream consisting of a stream header, then a series of 126 * malloc type headers and statistics structures (quantity maxcpus). For 127 * convenience, the kernel will provide the current value of maxcpus at the 128 * head of the stream. 129 */ 130 #define MALLOC_TYPE_STREAM_VERSION 0x00000001 131 struct malloc_type_stream_header { 132 uint32_t mtsh_version; /* Stream format version. */ 133 uint32_t mtsh_maxcpus; /* Value of MAXCPU for stream. */ 134 uint32_t mtsh_count; /* Number of records. */ 135 uint32_t _mtsh_pad; /* Pad/reserved field. */ 136 }; 137 138 #define MALLOC_MAX_NAME 32 139 struct malloc_type_header { 140 char mth_name[MALLOC_MAX_NAME]; 141 }; 142 143 #ifdef _KERNEL 144 #define MALLOC_DEFINE(type, shortdesc, longdesc) \ 145 struct malloc_type type[1] = { \ 146 { \ 147 .ks_next = NULL, \ 148 .ks_version = M_VERSION, \ 149 .ks_shortdesc = shortdesc, \ 150 } \ 151 }; \ 152 SYSINIT(type##_init, SI_SUB_KMEM, SI_ORDER_THIRD, malloc_init, \ 153 type); \ 154 SYSUNINIT(type##_uninit, SI_SUB_KMEM, SI_ORDER_ANY, \ 155 malloc_uninit, type) 156 157 #define MALLOC_DECLARE(type) \ 158 extern struct malloc_type type[1] 159 160 MALLOC_DECLARE(M_CACHE); 161 MALLOC_DECLARE(M_DEVBUF); 162 MALLOC_DECLARE(M_TEMP); 163 164 /* 165 * XXX this should be declared in <sys/uio.h>, but that tends to fail 166 * because <sys/uio.h> is included in a header before the source file 167 * has a chance to include <sys/malloc.h> to get MALLOC_DECLARE() defined. 168 */ 169 MALLOC_DECLARE(M_IOV); 170 171 struct domainset; 172 extern struct mtx malloc_mtx; 173 174 /* 175 * Function type used when iterating over the list of malloc types. 176 */ 177 typedef void malloc_type_list_func_t(struct malloc_type *, void *); 178 179 void contigfree(void *addr, unsigned long size, struct malloc_type *type); 180 void *contigmalloc(unsigned long size, struct malloc_type *type, int flags, 181 vm_paddr_t low, vm_paddr_t high, unsigned long alignment, 182 vm_paddr_t boundary) __malloc_like __result_use_check 183 __alloc_size(1) __alloc_align(6); 184 void *contigmalloc_domainset(unsigned long size, struct malloc_type *type, 185 struct domainset *ds, int flags, vm_paddr_t low, vm_paddr_t high, 186 unsigned long alignment, vm_paddr_t boundary) 187 __malloc_like __result_use_check __alloc_size(1) __alloc_align(7); 188 void free(void *addr, struct malloc_type *type); 189 void zfree(void *addr, struct malloc_type *type); 190 void *malloc(size_t size, struct malloc_type *type, int flags) __malloc_like 191 __result_use_check __alloc_size(1); 192 /* 193 * Try to optimize malloc(..., ..., M_ZERO) allocations by doing zeroing in 194 * place if the size is known at compilation time. 195 * 196 * Passing the flag down requires malloc to blindly zero the entire object. 197 * In practice a lot of the zeroing can be avoided if most of the object 198 * gets explicitly initialized after the allocation. Letting the compiler 199 * zero in place gives it the opportunity to take advantage of this state. 200 * 201 * Note that the operation is only applicable if both flags and size are 202 * known at compilation time. If M_ZERO is passed but M_WAITOK is not, the 203 * allocation can fail and a NULL check is needed. However, if M_WAITOK is 204 * passed we know the allocation must succeed and the check can be elided. 205 * 206 * _malloc_item = malloc(_size, type, (flags) &~ M_ZERO); 207 * if (((flags) & M_WAITOK) != 0 || _malloc_item != NULL) 208 * bzero(_malloc_item, _size); 209 * 210 * If the flag is set, the compiler knows the left side is always true, 211 * therefore the entire statement is true and the callsite is: 212 * 213 * _malloc_item = malloc(_size, type, (flags) &~ M_ZERO); 214 * bzero(_malloc_item, _size); 215 * 216 * If the flag is not set, the compiler knows the left size is always false 217 * and the NULL check is needed, therefore the callsite is: 218 * 219 * _malloc_item = malloc(_size, type, (flags) &~ M_ZERO); 220 * if (_malloc_item != NULL) 221 * bzero(_malloc_item, _size); 222 * 223 * The implementation is a macro because of what appears to be a clang 6 bug: 224 * an inline function variant ended up being compiled to a mere malloc call 225 * regardless of argument. gcc generates expected code (like the above). 226 */ 227 #define malloc(size, type, flags) ({ \ 228 void *_malloc_item; \ 229 size_t _size = (size); \ 230 if (__builtin_constant_p(size) && __builtin_constant_p(flags) &&\ 231 ((flags) & M_ZERO) != 0) { \ 232 _malloc_item = malloc(_size, type, (flags) &~ M_ZERO); \ 233 if (((flags) & M_WAITOK) != 0 || \ 234 __predict_true(_malloc_item != NULL)) \ 235 bzero(_malloc_item, _size); \ 236 } else { \ 237 _malloc_item = malloc(_size, type, flags); \ 238 } \ 239 _malloc_item; \ 240 }) 241 242 void *malloc_domainset(size_t size, struct malloc_type *type, 243 struct domainset *ds, int flags) __malloc_like __result_use_check 244 __alloc_size(1); 245 void *mallocarray(size_t nmemb, size_t size, struct malloc_type *type, 246 int flags) __malloc_like __result_use_check 247 __alloc_size2(1, 2); 248 void *malloc_exec(size_t size, struct malloc_type *type, int flags) __malloc_like 249 __result_use_check __alloc_size(1); 250 void *malloc_domainset_exec(size_t size, struct malloc_type *type, 251 struct domainset *ds, int flags) __malloc_like __result_use_check 252 __alloc_size(1); 253 void malloc_init(void *); 254 void malloc_type_allocated(struct malloc_type *type, unsigned long size); 255 void malloc_type_freed(struct malloc_type *type, unsigned long size); 256 void malloc_type_list(malloc_type_list_func_t *, void *); 257 void malloc_uninit(void *); 258 size_t malloc_size(size_t); 259 size_t malloc_usable_size(const void *); 260 void *realloc(void *addr, size_t size, struct malloc_type *type, int flags) 261 __result_use_check __alloc_size(2); 262 void *reallocf(void *addr, size_t size, struct malloc_type *type, int flags) 263 __result_use_check __alloc_size(2); 264 265 struct malloc_type *malloc_desc2type(const char *desc); 266 267 /* 268 * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX 269 * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW 270 */ 271 #define MUL_NO_OVERFLOW (1UL << (sizeof(size_t) * 8 / 2)) 272 static inline bool 273 WOULD_OVERFLOW(size_t nmemb, size_t size) 274 { 275 276 return ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) && 277 nmemb > 0 && __SIZE_T_MAX / nmemb < size); 278 } 279 #undef MUL_NO_OVERFLOW 280 #endif /* _KERNEL */ 281 282 #else 283 /* 284 * The native stand malloc / free interface we're mapping to 285 */ 286 extern void Free(void *p, const char *file, int line); 287 extern void *Malloc(size_t bytes, const char *file, int line); 288 289 /* 290 * Minimal standalone malloc implementation / environment. None of the 291 * flags mean anything and there's no need declare malloc types. 292 * Define the simple alloc / free routines in terms of Malloc and 293 * Free. None of the kernel features that this stuff disables are needed. 294 * 295 * XXX we are setting ourselves up for a potential crash if we can't allocate 296 * memory for a M_WAITOK call. 297 */ 298 #define M_WAITOK 0 299 #define M_ZERO 0 300 #define M_NOWAIT 0 301 #define MALLOC_DECLARE(x) 302 303 #define kmem_zalloc(size, flags) Malloc((size), __FILE__, __LINE__) 304 #define kmem_free(p, size) Free(p, __FILE__, __LINE__) 305 306 /* 307 * ZFS mem.h define that's the OpenZFS porting layer way of saying 308 * M_WAITOK. Given the above, it will also be a nop. 309 */ 310 #define KM_SLEEP M_WAITOK 311 #endif /* _STANDALONE */ 312 #endif /* !_SYS_MALLOC_H_ */ 313