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 64 #define M_VERSION 2020110501 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 _Static_assert(sizeof(struct malloc_type_stats) == 64, 94 "allocations come from pcpu_zone_64"); 95 96 /* 97 * Index definitions for the mti_probes[] array. 98 */ 99 #define DTMALLOC_PROBE_MALLOC 0 100 #define DTMALLOC_PROBE_FREE 1 101 #define DTMALLOC_PROBE_MAX 2 102 103 struct malloc_type_internal { 104 uint32_t mti_probes[DTMALLOC_PROBE_MAX]; 105 /* DTrace probe ID array. */ 106 u_char mti_zone; 107 struct malloc_type_stats *mti_stats; 108 u_long mti_spare[8]; 109 }; 110 111 /* 112 * Public data structure describing a malloc type. 113 */ 114 struct malloc_type { 115 struct malloc_type *ks_next; /* Next in global chain. */ 116 u_long ks_version; /* Detect programmer error. */ 117 const char *ks_shortdesc; /* Printable type name. */ 118 struct malloc_type_internal ks_mti; 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 { \ 145 .ks_next = NULL, \ 146 .ks_version = M_VERSION, \ 147 .ks_shortdesc = shortdesc, \ 148 } \ 149 }; \ 150 SYSINIT(type##_init, SI_SUB_KMEM, SI_ORDER_THIRD, malloc_init, \ 151 type); \ 152 SYSUNINIT(type##_uninit, SI_SUB_KMEM, SI_ORDER_ANY, \ 153 malloc_uninit, type) 154 155 #define MALLOC_DECLARE(type) \ 156 extern struct malloc_type type[1] 157 158 MALLOC_DECLARE(M_CACHE); 159 MALLOC_DECLARE(M_DEVBUF); 160 MALLOC_DECLARE(M_TEMP); 161 162 /* 163 * XXX this should be declared in <sys/uio.h>, but that tends to fail 164 * because <sys/uio.h> is included in a header before the source file 165 * has a chance to include <sys/malloc.h> to get MALLOC_DECLARE() defined. 166 */ 167 MALLOC_DECLARE(M_IOV); 168 169 struct domainset; 170 extern struct mtx malloc_mtx; 171 172 /* 173 * Function type used when iterating over the list of malloc types. 174 */ 175 typedef void malloc_type_list_func_t(struct malloc_type *, void *); 176 177 void contigfree(void *addr, unsigned long size, struct malloc_type *type); 178 void *contigmalloc(unsigned long size, struct malloc_type *type, int flags, 179 vm_paddr_t low, vm_paddr_t high, unsigned long alignment, 180 vm_paddr_t boundary) __malloc_like __result_use_check 181 __alloc_size(1) __alloc_align(6); 182 void *contigmalloc_domainset(unsigned long size, struct malloc_type *type, 183 struct domainset *ds, int flags, vm_paddr_t low, vm_paddr_t high, 184 unsigned long alignment, vm_paddr_t boundary) 185 __malloc_like __result_use_check __alloc_size(1) __alloc_align(7); 186 void free(void *addr, struct malloc_type *type); 187 void zfree(void *addr, struct malloc_type *type); 188 void *malloc(size_t size, struct malloc_type *type, int flags) __malloc_like 189 __result_use_check __alloc_size(1); 190 /* 191 * Try to optimize malloc(..., ..., M_ZERO) allocations by doing zeroing in 192 * place if the size is known at compilation time. 193 * 194 * Passing the flag down requires malloc to blindly zero the entire object. 195 * In practice a lot of the zeroing can be avoided if most of the object 196 * gets explicitly initialized after the allocation. Letting the compiler 197 * zero in place gives it the opportunity to take advantage of this state. 198 * 199 * Note that the operation is only applicable if both flags and size are 200 * known at compilation time. If M_ZERO is passed but M_WAITOK is not, the 201 * allocation can fail and a NULL check is needed. However, if M_WAITOK is 202 * passed we know the allocation must succeed and the check can be elided. 203 * 204 * _malloc_item = malloc(_size, type, (flags) &~ M_ZERO); 205 * if (((flags) & M_WAITOK) != 0 || _malloc_item != NULL) 206 * bzero(_malloc_item, _size); 207 * 208 * If the flag is set, the compiler knows the left side is always true, 209 * therefore the entire statement is true and the callsite is: 210 * 211 * _malloc_item = malloc(_size, type, (flags) &~ M_ZERO); 212 * bzero(_malloc_item, _size); 213 * 214 * If the flag is not set, the compiler knows the left size is always false 215 * and the NULL check is needed, therefore the callsite is: 216 * 217 * _malloc_item = malloc(_size, type, (flags) &~ M_ZERO); 218 * if (_malloc_item != NULL) 219 * bzero(_malloc_item, _size); 220 * 221 * The implementation is a macro because of what appears to be a clang 6 bug: 222 * an inline function variant ended up being compiled to a mere malloc call 223 * regardless of argument. gcc generates expected code (like the above). 224 */ 225 #define malloc(size, type, flags) ({ \ 226 void *_malloc_item; \ 227 size_t _size = (size); \ 228 if (__builtin_constant_p(size) && __builtin_constant_p(flags) &&\ 229 ((flags) & M_ZERO) != 0) { \ 230 _malloc_item = malloc(_size, type, (flags) &~ M_ZERO); \ 231 if (((flags) & M_WAITOK) != 0 || \ 232 __predict_true(_malloc_item != NULL)) \ 233 memset(_malloc_item, 0, _size); \ 234 } else { \ 235 _malloc_item = malloc(_size, type, flags); \ 236 } \ 237 _malloc_item; \ 238 }) 239 240 void *malloc_domainset(size_t size, struct malloc_type *type, 241 struct domainset *ds, int flags) __malloc_like __result_use_check 242 __alloc_size(1); 243 void *mallocarray(size_t nmemb, size_t size, struct malloc_type *type, 244 int flags) __malloc_like __result_use_check 245 __alloc_size2(1, 2); 246 void *mallocarray_domainset(size_t nmemb, size_t size, struct malloc_type *type, 247 struct domainset *ds, int flags) __malloc_like __result_use_check 248 __alloc_size2(1, 2); 249 void *malloc_exec(size_t size, struct malloc_type *type, int flags) __malloc_like 250 __result_use_check __alloc_size(1); 251 void *malloc_domainset_exec(size_t size, struct malloc_type *type, 252 struct domainset *ds, int flags) __malloc_like __result_use_check 253 __alloc_size(1); 254 void malloc_init(void *); 255 void malloc_type_allocated(struct malloc_type *type, unsigned long size); 256 void malloc_type_freed(struct malloc_type *type, unsigned long size); 257 void malloc_type_list(malloc_type_list_func_t *, void *); 258 void malloc_uninit(void *); 259 size_t malloc_size(size_t); 260 size_t malloc_usable_size(const void *); 261 void *realloc(void *addr, size_t size, struct malloc_type *type, int flags) 262 __result_use_check __alloc_size(2); 263 void *reallocf(void *addr, size_t size, struct malloc_type *type, int flags) 264 __result_use_check __alloc_size(2); 265 void *malloc_aligned(size_t size, size_t align, struct malloc_type *type, 266 int flags) __malloc_like __result_use_check __alloc_size(1); 267 void *malloc_domainset_aligned(size_t size, size_t align, 268 struct malloc_type *mtp, struct domainset *ds, int flags) 269 __malloc_like __result_use_check __alloc_size(1); 270 271 struct malloc_type *malloc_desc2type(const char *desc); 272 273 /* 274 * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX 275 * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW 276 */ 277 #define MUL_NO_OVERFLOW (1UL << (sizeof(size_t) * 8 / 2)) 278 static inline bool 279 WOULD_OVERFLOW(size_t nmemb, size_t size) 280 { 281 282 return ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) && 283 nmemb > 0 && __SIZE_T_MAX / nmemb < size); 284 } 285 #undef MUL_NO_OVERFLOW 286 #endif /* _KERNEL */ 287 288 #else 289 /* 290 * The native stand malloc / free interface we're mapping to 291 */ 292 extern void Free(void *p, const char *file, int line); 293 extern void *Malloc(size_t bytes, const char *file, int line); 294 295 /* 296 * Minimal standalone malloc implementation / environment. None of the 297 * flags mean anything and there's no need declare malloc types. 298 * Define the simple alloc / free routines in terms of Malloc and 299 * Free. None of the kernel features that this stuff disables are needed. 300 */ 301 #define M_WAITOK 1 302 #define M_ZERO 0 303 #define M_NOWAIT 2 304 #define MALLOC_DECLARE(x) 305 306 #define kmem_zalloc(size, flags) ({ \ 307 void *p = Malloc((size), __FILE__, __LINE__); \ 308 if (p == NULL && (flags & M_WAITOK) != 0) \ 309 panic("Could not malloc %zd bytes with M_WAITOK from %s line %d", \ 310 (size_t)size, __FILE__, __LINE__); \ 311 p; \ 312 }) 313 314 #define kmem_free(p, size) Free(p, __FILE__, __LINE__) 315 316 /* 317 * ZFS mem.h define that's the OpenZFS porting layer way of saying 318 * M_WAITOK. Given the above, it will also be a nop. 319 */ 320 #define KM_SLEEP M_WAITOK 321 #define KM_NOSLEEP M_NOWAIT 322 #endif /* _STANDALONE */ 323 #endif /* !_SYS_MALLOC_H_ */ 324