1 /* 2 * Copyright (c) 2016-2020, Yann Collet, Facebook, Inc. 3 * All rights reserved. 4 * 5 * This source code is licensed under both the BSD-style license (found in the 6 * LICENSE file in the root directory of this source tree) and the GPLv2 (found 7 * in the COPYING file in the root directory of this source tree). 8 * You may select, at your option, one of the above-listed licenses. 9 */ 10 11 #ifndef MEM_H_MODULE 12 #define MEM_H_MODULE 13 14 #if defined (__cplusplus) 15 extern "C" { 16 #endif 17 18 /*-**************************************** 19 * Dependencies 20 ******************************************/ 21 #include <stddef.h> /* size_t, ptrdiff_t */ 22 #include <string.h> /* memcpy */ 23 24 25 /*-**************************************** 26 * Compiler specifics 27 ******************************************/ 28 #if defined(_MSC_VER) /* Visual Studio */ 29 # include <stdlib.h> /* _byteswap_ulong */ 30 # include <intrin.h> /* _byteswap_* */ 31 #endif 32 #if defined(__GNUC__) 33 # define MEM_STATIC static __inline __attribute__((unused)) 34 #elif defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) 35 # define MEM_STATIC static inline 36 #elif defined(_MSC_VER) 37 # define MEM_STATIC static __inline 38 #else 39 # define MEM_STATIC static /* this version may generate warnings for unused static functions; disable the relevant warning */ 40 #endif 41 42 #ifndef __has_builtin 43 # define __has_builtin(x) 0 /* compat. with non-clang compilers */ 44 #endif 45 46 /* code only tested on 32 and 64 bits systems */ 47 #define MEM_STATIC_ASSERT(c) { enum { MEM_static_assert = 1/(int)(!!(c)) }; } 48 MEM_STATIC void MEM_check(void) { MEM_STATIC_ASSERT((sizeof(size_t)==4) || (sizeof(size_t)==8)); } 49 50 /* detects whether we are being compiled under msan */ 51 #if defined (__has_feature) 52 # if __has_feature(memory_sanitizer) 53 # define MEMORY_SANITIZER 1 54 # endif 55 #endif 56 57 #if defined (MEMORY_SANITIZER) 58 /* Not all platforms that support msan provide sanitizers/msan_interface.h. 59 * We therefore declare the functions we need ourselves, rather than trying to 60 * include the header file... */ 61 62 #include <stdint.h> /* intptr_t */ 63 64 /* Make memory region fully initialized (without changing its contents). */ 65 void __msan_unpoison(const volatile void *a, size_t size); 66 67 /* Make memory region fully uninitialized (without changing its contents). 68 This is a legacy interface that does not update origin information. Use 69 __msan_allocated_memory() instead. */ 70 void __msan_poison(const volatile void *a, size_t size); 71 72 /* Returns the offset of the first (at least partially) poisoned byte in the 73 memory range, or -1 if the whole range is good. */ 74 intptr_t __msan_test_shadow(const volatile void *x, size_t size); 75 #endif 76 77 /* detects whether we are being compiled under asan */ 78 #if defined (ZFS_ASAN_ENABLED) 79 # define ADDRESS_SANITIZER 1 80 # define ZSTD_ASAN_DONT_POISON_WORKSPACE 81 #endif 82 83 #if defined (ADDRESS_SANITIZER) 84 /* Not all platforms that support asan provide sanitizers/asan_interface.h. 85 * We therefore declare the functions we need ourselves, rather than trying to 86 * include the header file... */ 87 88 /** 89 * Marks a memory region (<c>[addr, addr+size)</c>) as unaddressable. 90 * 91 * This memory must be previously allocated by your program. Instrumented 92 * code is forbidden from accessing addresses in this region until it is 93 * unpoisoned. This function is not guaranteed to poison the entire region - 94 * it could poison only a subregion of <c>[addr, addr+size)</c> due to ASan 95 * alignment restrictions. 96 * 97 * \note This function is not thread-safe because no two threads can poison or 98 * unpoison memory in the same memory region simultaneously. 99 * 100 * \param addr Start of memory region. 101 * \param size Size of memory region. */ 102 void __asan_poison_memory_region(void const volatile *addr, size_t size); 103 104 /** 105 * Marks a memory region (<c>[addr, addr+size)</c>) as addressable. 106 * 107 * This memory must be previously allocated by your program. Accessing 108 * addresses in this region is allowed until this region is poisoned again. 109 * This function could unpoison a super-region of <c>[addr, addr+size)</c> due 110 * to ASan alignment restrictions. 111 * 112 * \note This function is not thread-safe because no two threads can 113 * poison or unpoison memory in the same memory region simultaneously. 114 * 115 * \param addr Start of memory region. 116 * \param size Size of memory region. */ 117 void __asan_unpoison_memory_region(void const volatile *addr, size_t size); 118 #endif 119 120 121 /*-************************************************************** 122 * Basic Types 123 *****************************************************************/ 124 #if !defined (__VMS) && (defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) ) 125 # include <stdint.h> 126 typedef uint8_t BYTE; 127 typedef uint16_t U16; 128 typedef int16_t S16; 129 typedef uint32_t U32; 130 typedef int32_t S32; 131 typedef uint64_t U64; 132 typedef int64_t S64; 133 #else 134 # include <limits.h> 135 #if CHAR_BIT != 8 136 # error "this implementation requires char to be exactly 8-bit type" 137 #endif 138 typedef unsigned char BYTE; 139 #if USHRT_MAX != 65535 140 # error "this implementation requires short to be exactly 16-bit type" 141 #endif 142 typedef unsigned short U16; 143 typedef signed short S16; 144 #if UINT_MAX != 4294967295 145 # error "this implementation requires int to be exactly 32-bit type" 146 #endif 147 typedef unsigned int U32; 148 typedef signed int S32; 149 /* note : there are no limits defined for long long type in C90. 150 * limits exist in C99, however, in such case, <stdint.h> is preferred */ 151 typedef unsigned long long U64; 152 typedef signed long long S64; 153 #endif 154 155 156 /*-************************************************************** 157 * Memory I/O 158 *****************************************************************/ 159 /* MEM_FORCE_MEMORY_ACCESS : 160 * By default, access to unaligned memory is controlled by `memcpy()`, which is safe and portable. 161 * Unfortunately, on some target/compiler combinations, the generated assembly is sub-optimal. 162 * The below switch allow to select different access method for improved performance. 163 * Method 0 (default) : use `memcpy()`. Safe and portable. 164 * Method 1 : `__packed` statement. It depends on compiler extension (i.e., not portable). 165 * This method is safe if your compiler supports it, and *generally* as fast or faster than `memcpy`. 166 * Method 2 : direct access. This method is portable but violate C standard. 167 * It can generate buggy code on targets depending on alignment. 168 * In some circumstances, it's the only known way to get the most performance (i.e. GCC + ARMv6) 169 * See http://fastcompression.blogspot.fr/2015/08/accessing-unaligned-memory.html for details. 170 * Prefer these methods in priority order (0 > 1 > 2) 171 */ 172 #ifndef MEM_FORCE_MEMORY_ACCESS /* can be defined externally, on command line for example */ 173 # if defined(__GNUC__) && ( defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) ) 174 # define MEM_FORCE_MEMORY_ACCESS 2 175 # elif defined(__INTEL_COMPILER) || defined(__GNUC__) || defined(__ICCARM__) 176 # define MEM_FORCE_MEMORY_ACCESS 1 177 # endif 178 #endif 179 180 MEM_STATIC unsigned MEM_32bits(void) { return sizeof(size_t)==4; } 181 MEM_STATIC unsigned MEM_64bits(void) { return sizeof(size_t)==8; } 182 183 MEM_STATIC unsigned MEM_isLittleEndian(void) 184 { 185 const union { U32 u; BYTE c[4]; } one = { 1 }; /* don't use static : performance detrimental */ 186 return one.c[0]; 187 } 188 189 #if defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==2) 190 191 /* violates C standard, by lying on structure alignment. 192 Only use if no other choice to achieve best performance on target platform */ 193 MEM_STATIC U16 MEM_read16(const void* memPtr) { return *(const U16*) memPtr; } 194 MEM_STATIC U32 MEM_read32(const void* memPtr) { return *(const U32*) memPtr; } 195 MEM_STATIC U64 MEM_read64(const void* memPtr) { return *(const U64*) memPtr; } 196 MEM_STATIC size_t MEM_readST(const void* memPtr) { return *(const size_t*) memPtr; } 197 198 MEM_STATIC void MEM_write16(void* memPtr, U16 value) { *(U16*)memPtr = value; } 199 MEM_STATIC void MEM_write32(void* memPtr, U32 value) { *(U32*)memPtr = value; } 200 MEM_STATIC void MEM_write64(void* memPtr, U64 value) { *(U64*)memPtr = value; } 201 202 #elif defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==1) 203 204 /* __pack instructions are safer, but compiler specific, hence potentially problematic for some compilers */ 205 /* currently only defined for gcc and icc */ 206 #if defined(_MSC_VER) || (defined(__INTEL_COMPILER) && defined(WIN32)) 207 __pragma( pack(push, 1) ) 208 typedef struct { U16 v; } unalign16; 209 typedef struct { U32 v; } unalign32; 210 typedef struct { U64 v; } unalign64; 211 typedef struct { size_t v; } unalignArch; 212 __pragma( pack(pop) ) 213 #else 214 typedef struct { U16 v; } __attribute__((packed)) unalign16; 215 typedef struct { U32 v; } __attribute__((packed)) unalign32; 216 typedef struct { U64 v; } __attribute__((packed)) unalign64; 217 typedef struct { size_t v; } __attribute__((packed)) unalignArch; 218 #endif 219 220 MEM_STATIC U16 MEM_read16(const void* ptr) { return ((const unalign16*)ptr)->v; } 221 MEM_STATIC U32 MEM_read32(const void* ptr) { return ((const unalign32*)ptr)->v; } 222 MEM_STATIC U64 MEM_read64(const void* ptr) { return ((const unalign64*)ptr)->v; } 223 MEM_STATIC size_t MEM_readST(const void* ptr) { return ((const unalignArch*)ptr)->v; } 224 225 MEM_STATIC void MEM_write16(void* memPtr, U16 value) { ((unalign16*)memPtr)->v = value; } 226 MEM_STATIC void MEM_write32(void* memPtr, U32 value) { ((unalign32*)memPtr)->v = value; } 227 MEM_STATIC void MEM_write64(void* memPtr, U64 value) { ((unalign64*)memPtr)->v = value; } 228 229 #else 230 231 /* default method, safe and standard. 232 can sometimes prove slower */ 233 234 MEM_STATIC U16 MEM_read16(const void* memPtr) 235 { 236 U16 val; memcpy(&val, memPtr, sizeof(val)); return val; 237 } 238 239 MEM_STATIC U32 MEM_read32(const void* memPtr) 240 { 241 U32 val; memcpy(&val, memPtr, sizeof(val)); return val; 242 } 243 244 MEM_STATIC U64 MEM_read64(const void* memPtr) 245 { 246 U64 val; memcpy(&val, memPtr, sizeof(val)); return val; 247 } 248 249 MEM_STATIC size_t MEM_readST(const void* memPtr) 250 { 251 size_t val; memcpy(&val, memPtr, sizeof(val)); return val; 252 } 253 254 MEM_STATIC void MEM_write16(void* memPtr, U16 value) 255 { 256 memcpy(memPtr, &value, sizeof(value)); 257 } 258 259 MEM_STATIC void MEM_write32(void* memPtr, U32 value) 260 { 261 memcpy(memPtr, &value, sizeof(value)); 262 } 263 264 MEM_STATIC void MEM_write64(void* memPtr, U64 value) 265 { 266 memcpy(memPtr, &value, sizeof(value)); 267 } 268 269 #endif /* MEM_FORCE_MEMORY_ACCESS */ 270 271 MEM_STATIC U32 MEM_swap32(U32 in) 272 { 273 #if defined(_MSC_VER) /* Visual Studio */ 274 return _byteswap_ulong(in); 275 #elif (defined (__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 403)) \ 276 || (defined(__clang__) && __has_builtin(__builtin_bswap32)) 277 return __builtin_bswap32(in); 278 #else 279 return ((in << 24) & 0xff000000 ) | 280 ((in << 8) & 0x00ff0000 ) | 281 ((in >> 8) & 0x0000ff00 ) | 282 ((in >> 24) & 0x000000ff ); 283 #endif 284 } 285 286 MEM_STATIC U64 MEM_swap64(U64 in) 287 { 288 #if defined(_MSC_VER) /* Visual Studio */ 289 return _byteswap_uint64(in); 290 #elif (defined (__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 403)) \ 291 || (defined(__clang__) && __has_builtin(__builtin_bswap64)) 292 return __builtin_bswap64(in); 293 #else 294 return ((in << 56) & 0xff00000000000000ULL) | 295 ((in << 40) & 0x00ff000000000000ULL) | 296 ((in << 24) & 0x0000ff0000000000ULL) | 297 ((in << 8) & 0x000000ff00000000ULL) | 298 ((in >> 8) & 0x00000000ff000000ULL) | 299 ((in >> 24) & 0x0000000000ff0000ULL) | 300 ((in >> 40) & 0x000000000000ff00ULL) | 301 ((in >> 56) & 0x00000000000000ffULL); 302 #endif 303 } 304 305 MEM_STATIC size_t MEM_swapST(size_t in) 306 { 307 if (MEM_32bits()) 308 return (size_t)MEM_swap32((U32)in); 309 else 310 return (size_t)MEM_swap64((U64)in); 311 } 312 313 /*=== Little endian r/w ===*/ 314 315 MEM_STATIC U16 MEM_readLE16(const void* memPtr) 316 { 317 if (MEM_isLittleEndian()) 318 return MEM_read16(memPtr); 319 else { 320 const BYTE* p = (const BYTE*)memPtr; 321 return (U16)(p[0] + (p[1]<<8)); 322 } 323 } 324 325 MEM_STATIC void MEM_writeLE16(void* memPtr, U16 val) 326 { 327 if (MEM_isLittleEndian()) { 328 MEM_write16(memPtr, val); 329 } else { 330 BYTE* p = (BYTE*)memPtr; 331 p[0] = (BYTE)val; 332 p[1] = (BYTE)(val>>8); 333 } 334 } 335 336 MEM_STATIC U32 MEM_readLE24(const void* memPtr) 337 { 338 return MEM_readLE16(memPtr) + (((const BYTE*)memPtr)[2] << 16); 339 } 340 341 MEM_STATIC void MEM_writeLE24(void* memPtr, U32 val) 342 { 343 MEM_writeLE16(memPtr, (U16)val); 344 ((BYTE*)memPtr)[2] = (BYTE)(val>>16); 345 } 346 347 MEM_STATIC U32 MEM_readLE32(const void* memPtr) 348 { 349 if (MEM_isLittleEndian()) 350 return MEM_read32(memPtr); 351 else 352 return MEM_swap32(MEM_read32(memPtr)); 353 } 354 355 MEM_STATIC void MEM_writeLE32(void* memPtr, U32 val32) 356 { 357 if (MEM_isLittleEndian()) 358 MEM_write32(memPtr, val32); 359 else 360 MEM_write32(memPtr, MEM_swap32(val32)); 361 } 362 363 MEM_STATIC U64 MEM_readLE64(const void* memPtr) 364 { 365 if (MEM_isLittleEndian()) 366 return MEM_read64(memPtr); 367 else 368 return MEM_swap64(MEM_read64(memPtr)); 369 } 370 371 MEM_STATIC void MEM_writeLE64(void* memPtr, U64 val64) 372 { 373 if (MEM_isLittleEndian()) 374 MEM_write64(memPtr, val64); 375 else 376 MEM_write64(memPtr, MEM_swap64(val64)); 377 } 378 379 MEM_STATIC size_t MEM_readLEST(const void* memPtr) 380 { 381 if (MEM_32bits()) 382 return (size_t)MEM_readLE32(memPtr); 383 else 384 return (size_t)MEM_readLE64(memPtr); 385 } 386 387 MEM_STATIC void MEM_writeLEST(void* memPtr, size_t val) 388 { 389 if (MEM_32bits()) 390 MEM_writeLE32(memPtr, (U32)val); 391 else 392 MEM_writeLE64(memPtr, (U64)val); 393 } 394 395 /*=== Big endian r/w ===*/ 396 397 MEM_STATIC U32 MEM_readBE32(const void* memPtr) 398 { 399 if (MEM_isLittleEndian()) 400 return MEM_swap32(MEM_read32(memPtr)); 401 else 402 return MEM_read32(memPtr); 403 } 404 405 MEM_STATIC void MEM_writeBE32(void* memPtr, U32 val32) 406 { 407 if (MEM_isLittleEndian()) 408 MEM_write32(memPtr, MEM_swap32(val32)); 409 else 410 MEM_write32(memPtr, val32); 411 } 412 413 MEM_STATIC U64 MEM_readBE64(const void* memPtr) 414 { 415 if (MEM_isLittleEndian()) 416 return MEM_swap64(MEM_read64(memPtr)); 417 else 418 return MEM_read64(memPtr); 419 } 420 421 MEM_STATIC void MEM_writeBE64(void* memPtr, U64 val64) 422 { 423 if (MEM_isLittleEndian()) 424 MEM_write64(memPtr, MEM_swap64(val64)); 425 else 426 MEM_write64(memPtr, val64); 427 } 428 429 MEM_STATIC size_t MEM_readBEST(const void* memPtr) 430 { 431 if (MEM_32bits()) 432 return (size_t)MEM_readBE32(memPtr); 433 else 434 return (size_t)MEM_readBE64(memPtr); 435 } 436 437 MEM_STATIC void MEM_writeBEST(void* memPtr, size_t val) 438 { 439 if (MEM_32bits()) 440 MEM_writeBE32(memPtr, (U32)val); 441 else 442 MEM_writeBE64(memPtr, (U64)val); 443 } 444 445 446 #if defined (__cplusplus) 447 } 448 #endif 449 450 #endif /* MEM_H_MODULE */ 451