1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef __LINUX_COMPILER_TYPES_H 3 #define __LINUX_COMPILER_TYPES_H 4 5 /* 6 * __has_builtin is supported on gcc >= 10, clang >= 3 and icc >= 21. 7 * In the meantime, to support gcc < 10, we implement __has_builtin 8 * by hand. 9 */ 10 #ifndef __has_builtin 11 #define __has_builtin(x) (0) 12 #endif 13 14 #ifndef __ASSEMBLY__ 15 16 /* 17 * Skipped when running bindgen due to a libclang issue; 18 * see https://github.com/rust-lang/rust-bindgen/issues/2244. 19 */ 20 #if defined(CONFIG_DEBUG_INFO_BTF) && defined(CONFIG_PAHOLE_HAS_BTF_TAG) && \ 21 __has_attribute(btf_type_tag) && !defined(__BINDGEN__) 22 # define BTF_TYPE_TAG(value) __attribute__((btf_type_tag(#value))) 23 #else 24 # define BTF_TYPE_TAG(value) /* nothing */ 25 #endif 26 27 /* sparse defines __CHECKER__; see Documentation/dev-tools/sparse.rst */ 28 #ifdef __CHECKER__ 29 /* address spaces */ 30 # define __kernel __attribute__((address_space(0))) 31 # define __user __attribute__((noderef, address_space(__user))) 32 # define __iomem __attribute__((noderef, address_space(__iomem))) 33 # define __percpu __attribute__((noderef, address_space(__percpu))) 34 # define __rcu __attribute__((noderef, address_space(__rcu))) __chk_user_ptr(const volatile void __user * ptr)35 static inline void __chk_user_ptr(const volatile void __user *ptr) { } __chk_io_ptr(const volatile void __iomem * ptr)36 static inline void __chk_io_ptr(const volatile void __iomem *ptr) { } 37 /* context/locking */ 38 # define __must_hold(x) __attribute__((context(x,1,1))) 39 # define __acquires(x) __attribute__((context(x,0,1))) 40 # define __cond_acquires(x) __attribute__((context(x,0,-1))) 41 # define __releases(x) __attribute__((context(x,1,0))) 42 # define __acquire(x) __context__(x,1) 43 # define __release(x) __context__(x,-1) 44 # define __cond_lock(x,c) ((c) ? ({ __acquire(x); 1; }) : 0) 45 /* other */ 46 # define __force __attribute__((force)) 47 # define __nocast __attribute__((nocast)) 48 # define __safe __attribute__((safe)) 49 # define __private __attribute__((noderef)) 50 # define ACCESS_PRIVATE(p, member) (*((typeof((p)->member) __force *) &(p)->member)) 51 #else /* __CHECKER__ */ 52 /* address spaces */ 53 # define __kernel 54 # ifdef STRUCTLEAK_PLUGIN 55 # define __user __attribute__((user)) 56 # else 57 # define __user BTF_TYPE_TAG(user) 58 # endif 59 # define __iomem 60 # define __percpu BTF_TYPE_TAG(percpu) 61 # define __rcu BTF_TYPE_TAG(rcu) 62 63 # define __chk_user_ptr(x) (void)0 64 # define __chk_io_ptr(x) (void)0 65 /* context/locking */ 66 # define __must_hold(x) 67 # define __acquires(x) 68 # define __cond_acquires(x) 69 # define __releases(x) 70 # define __acquire(x) (void)0 71 # define __release(x) (void)0 72 # define __cond_lock(x,c) (c) 73 /* other */ 74 # define __force 75 # define __nocast 76 # define __safe 77 # define __private 78 # define ACCESS_PRIVATE(p, member) ((p)->member) 79 # define __builtin_warning(x, y...) (1) 80 #endif /* __CHECKER__ */ 81 82 /* Indirect macros required for expanded argument pasting, eg. __LINE__. */ 83 #define ___PASTE(a,b) a##b 84 #define __PASTE(a,b) ___PASTE(a,b) 85 86 #ifdef __KERNEL__ 87 88 /* Attributes */ 89 #include <linux/compiler_attributes.h> 90 91 #if CONFIG_FUNCTION_ALIGNMENT > 0 92 #define __function_aligned __aligned(CONFIG_FUNCTION_ALIGNMENT) 93 #else 94 #define __function_aligned 95 #endif 96 97 /* 98 * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-cold-function-attribute 99 * gcc: https://gcc.gnu.org/onlinedocs/gcc/Label-Attributes.html#index-cold-label-attribute 100 * 101 * When -falign-functions=N is in use, we must avoid the cold attribute as 102 * GCC drops the alignment for cold functions. Worse, GCC can implicitly mark 103 * callees of cold functions as cold themselves, so it's not sufficient to add 104 * __function_aligned here as that will not ensure that callees are correctly 105 * aligned. 106 * 107 * See: 108 * 109 * https://lore.kernel.org/lkml/Y77%2FqVgvaJidFpYt@FVFF77S0Q05N 110 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88345#c9 111 */ 112 #if defined(CONFIG_CC_HAS_SANE_FUNCTION_ALIGNMENT) || (CONFIG_FUNCTION_ALIGNMENT == 0) 113 #define __cold __attribute__((__cold__)) 114 #else 115 #define __cold 116 #endif 117 118 /* 119 * On x86-64 and arm64 targets, __preserve_most changes the calling convention 120 * of a function to make the code in the caller as unintrusive as possible. This 121 * convention behaves identically to the C calling convention on how arguments 122 * and return values are passed, but uses a different set of caller- and callee- 123 * saved registers. 124 * 125 * The purpose is to alleviates the burden of saving and recovering a large 126 * register set before and after the call in the caller. This is beneficial for 127 * rarely taken slow paths, such as error-reporting functions that may be called 128 * from hot paths. 129 * 130 * Note: This may conflict with instrumentation inserted on function entry which 131 * does not use __preserve_most or equivalent convention (if in assembly). Since 132 * function tracing assumes the normal C calling convention, where the attribute 133 * is supported, __preserve_most implies notrace. It is recommended to restrict 134 * use of the attribute to functions that should or already disable tracing. 135 * 136 * Optional: not supported by gcc. 137 * 138 * clang: https://clang.llvm.org/docs/AttributeReference.html#preserve-most 139 */ 140 #if __has_attribute(__preserve_most__) && (defined(CONFIG_X86_64) || defined(CONFIG_ARM64)) 141 # define __preserve_most notrace __attribute__((__preserve_most__)) 142 #else 143 # define __preserve_most 144 #endif 145 146 /* 147 * Annotating a function/variable with __retain tells the compiler to place 148 * the object in its own section and set the flag SHF_GNU_RETAIN. This flag 149 * instructs the linker to retain the object during garbage-cleanup or LTO 150 * phases. 151 * 152 * Note that the __used macro is also used to prevent functions or data 153 * being optimized out, but operates at the compiler/IR-level and may still 154 * allow unintended removal of objects during linking. 155 * 156 * Optional: only supported since gcc >= 11, clang >= 13 157 * 158 * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-retain-function-attribute 159 * clang: https://clang.llvm.org/docs/AttributeReference.html#retain 160 */ 161 #if __has_attribute(__retain__) && \ 162 (defined(CONFIG_LD_DEAD_CODE_DATA_ELIMINATION) || \ 163 defined(CONFIG_LTO_CLANG)) 164 # define __retain __attribute__((__retain__)) 165 #else 166 # define __retain 167 #endif 168 169 /* Compiler specific macros. */ 170 #ifdef __clang__ 171 #include <linux/compiler-clang.h> 172 #elif defined(__GNUC__) 173 /* The above compilers also define __GNUC__, so order is important here. */ 174 #include <linux/compiler-gcc.h> 175 #else 176 #error "Unknown compiler" 177 #endif 178 179 /* 180 * Some architectures need to provide custom definitions of macros provided 181 * by linux/compiler-*.h, and can do so using asm/compiler.h. We include that 182 * conditionally rather than using an asm-generic wrapper in order to avoid 183 * build failures if any C compilation, which will include this file via an 184 * -include argument in c_flags, occurs prior to the asm-generic wrappers being 185 * generated. 186 */ 187 #ifdef CONFIG_HAVE_ARCH_COMPILER_H 188 #include <asm/compiler.h> 189 #endif 190 191 struct ftrace_branch_data { 192 const char *func; 193 const char *file; 194 unsigned line; 195 union { 196 struct { 197 unsigned long correct; 198 unsigned long incorrect; 199 }; 200 struct { 201 unsigned long miss; 202 unsigned long hit; 203 }; 204 unsigned long miss_hit[2]; 205 }; 206 }; 207 208 struct ftrace_likely_data { 209 struct ftrace_branch_data data; 210 unsigned long constant; 211 }; 212 213 #if defined(CC_USING_HOTPATCH) 214 #define notrace __attribute__((hotpatch(0, 0))) 215 #elif defined(CC_USING_PATCHABLE_FUNCTION_ENTRY) 216 #define notrace __attribute__((patchable_function_entry(0, 0))) 217 #else 218 #define notrace __attribute__((__no_instrument_function__)) 219 #endif 220 221 /* 222 * it doesn't make sense on ARM (currently the only user of __naked) 223 * to trace naked functions because then mcount is called without 224 * stack and frame pointer being set up and there is no chance to 225 * restore the lr register to the value before mcount was called. 226 */ 227 #define __naked __attribute__((__naked__)) notrace 228 229 /* 230 * Prefer gnu_inline, so that extern inline functions do not emit an 231 * externally visible function. This makes extern inline behave as per gnu89 232 * semantics rather than c99. This prevents multiple symbol definition errors 233 * of extern inline functions at link time. 234 * A lot of inline functions can cause havoc with function tracing. 235 */ 236 #define inline inline __gnu_inline __inline_maybe_unused notrace 237 238 /* 239 * gcc provides both __inline__ and __inline as alternate spellings of 240 * the inline keyword, though the latter is undocumented. New kernel 241 * code should only use the inline spelling, but some existing code 242 * uses __inline__. Since we #define inline above, to ensure 243 * __inline__ has the same semantics, we need this #define. 244 * 245 * However, the spelling __inline is strictly reserved for referring 246 * to the bare keyword. 247 */ 248 #define __inline__ inline 249 250 /* 251 * GCC does not warn about unused static inline functions for -Wunused-function. 252 * Suppress the warning in clang as well by using __maybe_unused, but enable it 253 * for W=1 build. This will allow clang to find unused functions. Remove the 254 * __inline_maybe_unused entirely after fixing most of -Wunused-function warnings. 255 */ 256 #ifdef KBUILD_EXTRA_WARN1 257 #define __inline_maybe_unused 258 #else 259 #define __inline_maybe_unused __maybe_unused 260 #endif 261 262 /* 263 * Rather then using noinline to prevent stack consumption, use 264 * noinline_for_stack instead. For documentation reasons. 265 */ 266 #define noinline_for_stack noinline 267 268 /* 269 * Sanitizer helper attributes: Because using __always_inline and 270 * __no_sanitize_* conflict, provide helper attributes that will either expand 271 * to __no_sanitize_* in compilation units where instrumentation is enabled 272 * (__SANITIZE_*__), or __always_inline in compilation units without 273 * instrumentation (__SANITIZE_*__ undefined). 274 */ 275 #ifdef __SANITIZE_ADDRESS__ 276 /* 277 * We can't declare function 'inline' because __no_sanitize_address conflicts 278 * with inlining. Attempt to inline it may cause a build failure. 279 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67368 280 * '__maybe_unused' allows us to avoid defined-but-not-used warnings. 281 */ 282 # define __no_kasan_or_inline __no_sanitize_address notrace __maybe_unused 283 # define __no_sanitize_or_inline __no_kasan_or_inline 284 #else 285 # define __no_kasan_or_inline __always_inline 286 #endif 287 288 #ifdef __SANITIZE_THREAD__ 289 /* 290 * Clang still emits instrumentation for __tsan_func_{entry,exit}() and builtin 291 * atomics even with __no_sanitize_thread (to avoid false positives in userspace 292 * ThreadSanitizer). The kernel's requirements are stricter and we really do not 293 * want any instrumentation with __no_kcsan. 294 * 295 * Therefore we add __disable_sanitizer_instrumentation where available to 296 * disable all instrumentation. See Kconfig.kcsan where this is mandatory. 297 */ 298 # define __no_kcsan __no_sanitize_thread __disable_sanitizer_instrumentation 299 /* 300 * Type qualifier to mark variables where all data-racy accesses should be 301 * ignored by KCSAN. Note, the implementation simply marks these variables as 302 * volatile, since KCSAN will treat such accesses as "marked". 303 */ 304 # define __data_racy volatile 305 # define __no_sanitize_or_inline __no_kcsan notrace __maybe_unused 306 #else 307 # define __no_kcsan 308 # define __data_racy 309 #endif 310 311 #ifdef __SANITIZE_MEMORY__ 312 /* 313 * Similarly to KASAN and KCSAN, KMSAN loses function attributes of inlined 314 * functions, therefore disabling KMSAN checks also requires disabling inlining. 315 * 316 * __no_sanitize_or_inline effectively prevents KMSAN from reporting errors 317 * within the function and marks all its outputs as initialized. 318 */ 319 # define __no_sanitize_or_inline __no_kmsan_checks notrace __maybe_unused 320 #endif 321 322 #ifndef __no_sanitize_or_inline 323 #define __no_sanitize_or_inline __always_inline 324 #endif 325 326 /* 327 * Apply __counted_by() when the Endianness matches to increase test coverage. 328 */ 329 #ifdef __LITTLE_ENDIAN 330 #define __counted_by_le(member) __counted_by(member) 331 #define __counted_by_be(member) 332 #else 333 #define __counted_by_le(member) 334 #define __counted_by_be(member) __counted_by(member) 335 #endif 336 337 /* Do not trap wrapping arithmetic within an annotated function. */ 338 #ifdef CONFIG_UBSAN_SIGNED_WRAP 339 # define __signed_wrap __attribute__((no_sanitize("signed-integer-overflow"))) 340 #else 341 # define __signed_wrap 342 #endif 343 344 /* Section for code which can't be instrumented at all */ 345 #define __noinstr_section(section) \ 346 noinline notrace __attribute((__section__(section))) \ 347 __no_kcsan __no_sanitize_address __no_profile __no_sanitize_coverage \ 348 __no_sanitize_memory __signed_wrap 349 350 #define noinstr __noinstr_section(".noinstr.text") 351 352 /* 353 * The __cpuidle section is used twofold: 354 * 355 * 1) the original use -- identifying if a CPU is 'stuck' in idle state based 356 * on it's instruction pointer. See cpu_in_idle(). 357 * 358 * 2) supressing instrumentation around where cpuidle disables RCU; where the 359 * function isn't strictly required for #1, this is interchangeable with 360 * noinstr. 361 */ 362 #define __cpuidle __noinstr_section(".cpuidle.text") 363 364 #endif /* __KERNEL__ */ 365 366 #endif /* __ASSEMBLY__ */ 367 368 /* 369 * The below symbols may be defined for one or more, but not ALL, of the above 370 * compilers. We don't consider that to be an error, so set them to nothing. 371 * For example, some of them are for compiler specific plugins. 372 */ 373 #ifndef __latent_entropy 374 # define __latent_entropy 375 #endif 376 377 #if defined(RANDSTRUCT) && !defined(__CHECKER__) 378 # define __randomize_layout __designated_init __attribute__((randomize_layout)) 379 # define __no_randomize_layout __attribute__((no_randomize_layout)) 380 /* This anon struct can add padding, so only enable it under randstruct. */ 381 # define randomized_struct_fields_start struct { 382 # define randomized_struct_fields_end } __randomize_layout; 383 #else 384 # define __randomize_layout __designated_init 385 # define __no_randomize_layout 386 # define randomized_struct_fields_start 387 # define randomized_struct_fields_end 388 #endif 389 390 #ifndef __noscs 391 # define __noscs 392 #endif 393 394 #ifndef __nocfi 395 # define __nocfi 396 #endif 397 398 /* 399 * Any place that could be marked with the "alloc_size" attribute is also 400 * a place to be marked with the "malloc" attribute, except those that may 401 * be performing a _reallocation_, as that may alias the existing pointer. 402 * For these, use __realloc_size(). 403 */ 404 #ifdef __alloc_size__ 405 # define __alloc_size(x, ...) __alloc_size__(x, ## __VA_ARGS__) __malloc 406 # define __realloc_size(x, ...) __alloc_size__(x, ## __VA_ARGS__) 407 #else 408 # define __alloc_size(x, ...) __malloc 409 # define __realloc_size(x, ...) 410 #endif 411 412 /* 413 * When the size of an allocated object is needed, use the best available 414 * mechanism to find it. (For cases where sizeof() cannot be used.) 415 */ 416 #if __has_builtin(__builtin_dynamic_object_size) 417 #define __struct_size(p) __builtin_dynamic_object_size(p, 0) 418 #define __member_size(p) __builtin_dynamic_object_size(p, 1) 419 #else 420 #define __struct_size(p) __builtin_object_size(p, 0) 421 #define __member_size(p) __builtin_object_size(p, 1) 422 #endif 423 424 /* Determine if an attribute has been applied to a variable. */ 425 #if __has_builtin(__builtin_has_attribute) 426 #define __annotated(var, attr) __builtin_has_attribute(var, attr) 427 #else 428 #define __annotated(var, attr) (false) 429 #endif 430 431 /* 432 * Some versions of gcc do not mark 'asm goto' volatile: 433 * 434 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103979 435 * 436 * We do it here by hand, because it doesn't hurt. 437 */ 438 #ifndef asm_goto_output 439 #define asm_goto_output(x...) asm volatile goto(x) 440 #endif 441 442 /* 443 * Clang has trouble with constraints with multiple 444 * alternative behaviors (mainly "g" and "rm"). 445 */ 446 #ifndef ASM_INPUT_G 447 #define ASM_INPUT_G "g" 448 #define ASM_INPUT_RM "rm" 449 #endif 450 451 #ifdef CONFIG_CC_HAS_ASM_INLINE 452 #define asm_inline asm __inline 453 #else 454 #define asm_inline asm 455 #endif 456 457 /* Are two types/vars the same type (ignoring qualifiers)? */ 458 #define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b)) 459 460 /* 461 * __unqual_scalar_typeof(x) - Declare an unqualified scalar type, leaving 462 * non-scalar types unchanged. 463 */ 464 /* 465 * Prefer C11 _Generic for better compile-times and simpler code. Note: 'char' 466 * is not type-compatible with 'signed char', and we define a separate case. 467 */ 468 #define __scalar_type_to_expr_cases(type) \ 469 unsigned type: (unsigned type)0, \ 470 signed type: (signed type)0 471 472 #define __unqual_scalar_typeof(x) typeof( \ 473 _Generic((x), \ 474 char: (char)0, \ 475 __scalar_type_to_expr_cases(char), \ 476 __scalar_type_to_expr_cases(short), \ 477 __scalar_type_to_expr_cases(int), \ 478 __scalar_type_to_expr_cases(long), \ 479 __scalar_type_to_expr_cases(long long), \ 480 default: (x))) 481 482 /* Is this type a native word size -- useful for atomic operations */ 483 #define __native_word(t) \ 484 (sizeof(t) == sizeof(char) || sizeof(t) == sizeof(short) || \ 485 sizeof(t) == sizeof(int) || sizeof(t) == sizeof(long)) 486 487 #ifdef __OPTIMIZE__ 488 # define __compiletime_assert(condition, msg, prefix, suffix) \ 489 do { \ 490 /* \ 491 * __noreturn is needed to give the compiler enough \ 492 * information to avoid certain possibly-uninitialized \ 493 * warnings (regardless of the build failing). \ 494 */ \ 495 __noreturn extern void prefix ## suffix(void) \ 496 __compiletime_error(msg); \ 497 if (!(condition)) \ 498 prefix ## suffix(); \ 499 } while (0) 500 #else 501 # define __compiletime_assert(condition, msg, prefix, suffix) do { } while (0) 502 #endif 503 504 #define _compiletime_assert(condition, msg, prefix, suffix) \ 505 __compiletime_assert(condition, msg, prefix, suffix) 506 507 /** 508 * compiletime_assert - break build and emit msg if condition is false 509 * @condition: a compile-time constant condition to check 510 * @msg: a message to emit if condition is false 511 * 512 * In tradition of POSIX assert, this macro will break the build if the 513 * supplied condition is *false*, emitting the supplied error message if the 514 * compiler has support to do so. 515 */ 516 #define compiletime_assert(condition, msg) \ 517 _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) 518 519 #define compiletime_assert_atomic_type(t) \ 520 compiletime_assert(__native_word(t), \ 521 "Need native word sized stores/loads for atomicity.") 522 523 /* Helpers for emitting diagnostics in pragmas. */ 524 #ifndef __diag 525 #define __diag(string) 526 #endif 527 528 #ifndef __diag_GCC 529 #define __diag_GCC(version, severity, string) 530 #endif 531 532 #define __diag_push() __diag(push) 533 #define __diag_pop() __diag(pop) 534 535 #define __diag_ignore(compiler, version, option, comment) \ 536 __diag_ ## compiler(version, ignore, option) 537 #define __diag_warn(compiler, version, option, comment) \ 538 __diag_ ## compiler(version, warn, option) 539 #define __diag_error(compiler, version, option, comment) \ 540 __diag_ ## compiler(version, error, option) 541 542 #ifndef __diag_ignore_all 543 #define __diag_ignore_all(option, comment) 544 #endif 545 546 #endif /* __LINUX_COMPILER_TYPES_H */ 547