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 34 #ifndef _SYS_MALLOC_H_ 35 #define _SYS_MALLOC_H_ 36 37 #ifndef _STANDALONE 38 #include <sys/param.h> 39 #ifdef _KERNEL 40 #include <sys/systm.h> 41 #endif 42 #include <sys/queue.h> 43 #include <sys/_lock.h> 44 #include <sys/_mutex.h> 45 #include <machine/_limits.h> 46 47 #define MINALLOCSIZE UMA_SMALLEST_UNIT 48 49 /* 50 * Flags to memory allocation functions. 51 */ 52 #define M_NOWAIT 0x0001 /* do not block */ 53 #define M_WAITOK 0x0002 /* ok to block */ 54 #define M_NORECLAIM 0x0080 /* do not reclaim after failure */ 55 #define M_ZERO 0x0100 /* bzero the allocation */ 56 #define M_NOVM 0x0200 /* don't ask VM for pages */ 57 #define M_USE_RESERVE 0x0400 /* can alloc out of reserve memory */ 58 #define M_NODUMP 0x0800 /* don't dump pages in this allocation */ 59 #define M_FIRSTFIT 0x1000 /* only for vmem, fast fit */ 60 #define M_BESTFIT 0x2000 /* only for vmem, low fragmentation */ 61 #define M_EXEC 0x4000 /* allocate executable space */ 62 #define M_NEXTFIT 0x8000 /* only for vmem, follow cursor */ 63 #define M_NEVERFREED 0x10000 /* chunk will never get freed */ 64 65 #define M_VERSION 2024073001 66 67 /* 68 * Two malloc type structures are present: malloc_type, which is used by a 69 * type owner to declare the type, and malloc_type_internal, which holds 70 * malloc-owned statistics and other ABI-sensitive fields, such as the set of 71 * malloc statistics indexed by the compile-time MAXCPU constant. 72 * Applications should avoid introducing dependence on the allocator private 73 * data layout and size. 74 * 75 * The malloc_type ks_next field is protected by malloc_mtx. Other fields in 76 * malloc_type are static after initialization so unsynchronized. 77 * 78 * Statistics in malloc_type_stats are written only when holding a critical 79 * section and running on the CPU associated with the index into the stat 80 * array, but read lock-free resulting in possible (minor) races, which the 81 * monitoring app should take into account. 82 */ 83 struct malloc_type_stats { 84 uint64_t mts_memalloced; /* Bytes allocated on CPU. */ 85 uint64_t mts_memfreed; /* Bytes freed on CPU. */ 86 uint64_t mts_numallocs; /* Number of allocates on CPU. */ 87 uint64_t mts_numfrees; /* number of frees on CPU. */ 88 uint64_t mts_size; /* Bitmask of sizes allocated on CPU. */ 89 uint64_t _mts_reserved1; /* Reserved field. */ 90 uint64_t _mts_reserved2; /* Reserved field. */ 91 uint64_t _mts_reserved3; /* Reserved field. */ 92 }; 93 94 _Static_assert(sizeof(struct malloc_type_stats) == 64, 95 "allocations come from pcpu_zone_64"); 96 97 /* 98 * Index definitions for the mti_probes[] array. 99 */ 100 #define DTMALLOC_PROBE_MALLOC 0 101 #define DTMALLOC_PROBE_FREE 1 102 #define DTMALLOC_PROBE_MAX 2 103 104 struct malloc_type_internal { 105 uint32_t mti_probes[DTMALLOC_PROBE_MAX]; 106 /* DTrace probe ID array. */ 107 u_char mti_zone; 108 struct malloc_type_stats *mti_stats; 109 u_long mti_spare[8]; 110 }; 111 112 /* 113 * Public data structure describing a malloc type. 114 */ 115 struct malloc_type { 116 struct malloc_type *ks_next; /* Next in global chain. */ 117 u_long ks_version; /* Detect programmer error. */ 118 const char *ks_shortdesc; /* Printable type name. */ 119 struct malloc_type_internal ks_mti; 120 }; 121 122 /* 123 * Statistics structure headers for user space. The kern.malloc sysctl 124 * exposes a structure stream consisting of a stream header, then a series of 125 * malloc type headers and statistics structures (quantity maxcpus). For 126 * convenience, the kernel will provide the current value of maxcpus at the 127 * head of the stream. 128 */ 129 #define MALLOC_TYPE_STREAM_VERSION 0x00000001 130 struct malloc_type_stream_header { 131 uint32_t mtsh_version; /* Stream format version. */ 132 uint32_t mtsh_maxcpus; /* Value of MAXCPU for stream. */ 133 uint32_t mtsh_count; /* Number of records. */ 134 uint32_t _mtsh_pad; /* Pad/reserved field. */ 135 }; 136 137 #define MALLOC_MAX_NAME 32 138 struct malloc_type_header { 139 char mth_name[MALLOC_MAX_NAME]; 140 }; 141 142 #ifdef _KERNEL 143 #define MALLOC_DEFINE(type, shortdesc, longdesc) \ 144 struct malloc_type type[1] = { \ 145 { \ 146 .ks_next = NULL, \ 147 .ks_version = M_VERSION, \ 148 .ks_shortdesc = shortdesc, \ 149 } \ 150 }; \ 151 SYSINIT(type##_init, SI_SUB_KMEM, SI_ORDER_THIRD, malloc_init, \ 152 type); \ 153 SYSUNINIT(type##_uninit, SI_SUB_KMEM, SI_ORDER_ANY, \ 154 malloc_uninit, type) 155 156 #define MALLOC_DECLARE(type) \ 157 extern struct malloc_type type[1] 158 159 MALLOC_DECLARE(M_CACHE); 160 MALLOC_DECLARE(M_DEVBUF); 161 MALLOC_DECLARE(M_PARGS); 162 MALLOC_DECLARE(M_SESSION); 163 MALLOC_DECLARE(M_SUBPROC); 164 MALLOC_DECLARE(M_TEMP); 165 166 /* 167 * XXX this should be declared in <sys/uio.h>, but that tends to fail 168 * because <sys/uio.h> is included in a header before the source file 169 * has a chance to include <sys/malloc.h> to get MALLOC_DECLARE() defined. 170 */ 171 MALLOC_DECLARE(M_IOV); 172 173 struct domainset; 174 extern struct mtx malloc_mtx; 175 176 /* 177 * Function type used when iterating over the list of malloc types. 178 */ 179 typedef void malloc_type_list_func_t(struct malloc_type *, void *); 180 181 /* contigfree(9) is deprecated. */ 182 void contigfree(void *addr, unsigned long, struct malloc_type *type); 183 void *contigmalloc(unsigned long size, struct malloc_type *type, int flags, 184 vm_paddr_t low, vm_paddr_t high, unsigned long alignment, 185 vm_paddr_t boundary) __malloc_like __result_use_check 186 __alloc_size(1) __alloc_align(6); 187 void *contigmalloc_domainset(unsigned long size, struct malloc_type *type, 188 struct domainset *ds, int flags, vm_paddr_t low, vm_paddr_t high, 189 unsigned long alignment, vm_paddr_t boundary) 190 __malloc_like __result_use_check __alloc_size(1) __alloc_align(7); 191 void free(void *addr, struct malloc_type *type); 192 void zfree(void *addr, struct malloc_type *type); 193 void *malloc(size_t size, struct malloc_type *type, int flags) __malloc_like 194 __result_use_check __alloc_size(1); 195 /* 196 * Try to optimize malloc(..., ..., M_ZERO) allocations by doing zeroing in 197 * place if the size is known at compilation time. 198 * 199 * Passing the flag down requires malloc to blindly zero the entire object. 200 * In practice a lot of the zeroing can be avoided if most of the object 201 * gets explicitly initialized after the allocation. Letting the compiler 202 * zero in place gives it the opportunity to take advantage of this state. 203 * 204 * Note that the operation is only applicable if both flags and size are 205 * known at compilation time. If M_ZERO is passed but M_WAITOK is not, the 206 * allocation can fail and a NULL check is needed. However, if M_WAITOK is 207 * passed we know the allocation must succeed and the check can be elided. 208 * 209 * _malloc_item = malloc(_size, type, (flags) &~ M_ZERO); 210 * if (((flags) & M_WAITOK) != 0 || _malloc_item != NULL) 211 * bzero(_malloc_item, _size); 212 * 213 * If the flag is set, the compiler knows the left side is always true, 214 * therefore the entire statement is true and the callsite is: 215 * 216 * _malloc_item = malloc(_size, type, (flags) &~ M_ZERO); 217 * bzero(_malloc_item, _size); 218 * 219 * If the flag is not set, the compiler knows the left size is always false 220 * and the NULL check is needed, therefore the callsite is: 221 * 222 * _malloc_item = malloc(_size, type, (flags) &~ M_ZERO); 223 * if (_malloc_item != NULL) 224 * bzero(_malloc_item, _size); 225 * 226 * The implementation is a macro because of what appears to be a clang 6 bug: 227 * an inline function variant ended up being compiled to a mere malloc call 228 * regardless of argument. gcc generates expected code (like the above). 229 */ 230 #define malloc(size, type, flags) ({ \ 231 void *_malloc_item; \ 232 size_t _size = (size); \ 233 if (__builtin_constant_p(size) && __builtin_constant_p(flags) &&\ 234 ((flags) & M_ZERO) != 0) { \ 235 _malloc_item = malloc(_size, type, (flags) &~ M_ZERO); \ 236 if (((flags) & M_WAITOK) != 0 || \ 237 __predict_true(_malloc_item != NULL)) \ 238 memset(_malloc_item, 0, _size); \ 239 } else { \ 240 _malloc_item = malloc(_size, type, flags); \ 241 } \ 242 _malloc_item; \ 243 }) 244 245 void *malloc_domainset(size_t size, struct malloc_type *type, 246 struct domainset *ds, int flags) __malloc_like __result_use_check 247 __alloc_size(1); 248 void *mallocarray(size_t nmemb, size_t size, struct malloc_type *type, 249 int flags) __malloc_like __result_use_check 250 __alloc_size2(1, 2); 251 void *mallocarray_domainset(size_t nmemb, size_t size, struct malloc_type *type, 252 struct domainset *ds, int flags) __malloc_like __result_use_check 253 __alloc_size2(1, 2); 254 void *malloc_exec(size_t size, struct malloc_type *type, int flags) __malloc_like 255 __result_use_check __alloc_size(1); 256 void *malloc_domainset_exec(size_t size, struct malloc_type *type, 257 struct domainset *ds, int flags) __malloc_like __result_use_check 258 __alloc_size(1); 259 void malloc_init(void *); 260 void malloc_type_allocated(struct malloc_type *type, unsigned long size); 261 void malloc_type_freed(struct malloc_type *type, unsigned long size); 262 void malloc_type_list(malloc_type_list_func_t *, void *); 263 void malloc_uninit(void *); 264 size_t malloc_size(size_t); 265 size_t malloc_usable_size(const void *); 266 void *realloc(void *addr, size_t size, struct malloc_type *type, int flags) 267 __result_use_check __alloc_size(2); 268 void *reallocf(void *addr, size_t size, struct malloc_type *type, int flags) 269 __result_use_check __alloc_size(2); 270 void *malloc_aligned(size_t size, size_t align, struct malloc_type *type, 271 int flags) __malloc_like __result_use_check __alloc_size(1); 272 void *malloc_domainset_aligned(size_t size, size_t align, 273 struct malloc_type *mtp, struct domainset *ds, int flags) 274 __malloc_like __result_use_check __alloc_size(1); 275 276 struct malloc_type *malloc_desc2type(const char *desc); 277 278 /* 279 * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX 280 * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW 281 */ 282 #define MUL_NO_OVERFLOW (1UL << (sizeof(size_t) * 8 / 2)) 283 static inline bool 284 WOULD_OVERFLOW(size_t nmemb, size_t size) 285 { 286 287 return ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) && 288 nmemb > 0 && __SIZE_T_MAX / nmemb < size); 289 } 290 #undef MUL_NO_OVERFLOW 291 #endif /* _KERNEL */ 292 293 #else 294 /* 295 * The native stand malloc / free interface we're mapping to 296 */ 297 extern void Free(void *p, const char *file, int line); 298 extern void *Malloc(size_t bytes, const char *file, int line); 299 300 /* 301 * Minimal standalone malloc implementation / environment. None of the 302 * flags mean anything and there's no need declare malloc types. 303 * Define the simple alloc / free routines in terms of Malloc and 304 * Free. None of the kernel features that this stuff disables are needed. 305 */ 306 #define M_WAITOK 1 307 #define M_ZERO 0 308 #define M_NOWAIT 2 309 #define MALLOC_DECLARE(x) 310 311 #define kmem_zalloc(size, flags) ({ \ 312 void *p = Malloc((size), __FILE__, __LINE__); \ 313 if (p == NULL && (flags & M_WAITOK) != 0) \ 314 panic("Could not malloc %zd bytes with M_WAITOK from %s line %d", \ 315 (size_t)size, __FILE__, __LINE__); \ 316 p; \ 317 }) 318 319 #define kmem_free(p, size) Free(p, __FILE__, __LINE__) 320 321 /* 322 * ZFS mem.h define that's the OpenZFS porting layer way of saying 323 * M_WAITOK. Given the above, it will also be a nop. 324 */ 325 #define KM_SLEEP M_WAITOK 326 #define KM_NOSLEEP M_NOWAIT 327 #endif /* _STANDALONE */ 328 #endif /* !_SYS_MALLOC_H_ */ 329