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