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1/* SPDX-License-Identifier: GPL-2.0 */2#ifndef __LINUX_COMPILER_TYPES_H3#define __LINUX_COMPILER_TYPES_H4 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_builtin8 * by hand.9 */10#ifndef __has_builtin11#define __has_builtin(x) (0)12#endif13 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#else24# define BTF_TYPE_TAG(value) /* nothing */25#endif26 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)))35static inline void __chk_user_ptr(const volatile void __user *ptr) { }36static 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 __kernel54# ifdef STRUCTLEAK_PLUGIN55# define __user __attribute__((user))56# else57# define __user BTF_TYPE_TAG(user)58# endif59# define __iomem60# define __percpu BTF_TYPE_TAG(percpu)61# define __rcu BTF_TYPE_TAG(rcu)62 63# define __chk_user_ptr(x) (void)064# define __chk_io_ptr(x) (void)065/* 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)071# define __release(x) (void)072# define __cond_lock(x,c) (c)73/* other */74# define __force75# define __nocast76# define __safe77# define __private78# 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##b84#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 > 092#define __function_aligned __aligned(CONFIG_FUNCTION_ALIGNMENT)93#else94#define __function_aligned95#endif96 97/*98 * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-cold-function-attribute99 * gcc: https://gcc.gnu.org/onlinedocs/gcc/Label-Attributes.html#index-cold-label-attribute100 *101 * When -falign-functions=N is in use, we must avoid the cold attribute as102 * GCC drops the alignment for cold functions. Worse, GCC can implicitly mark103 * callees of cold functions as cold themselves, so it's not sufficient to add104 * __function_aligned here as that will not ensure that callees are correctly105 * aligned.106 *107 * See:108 *109 * https://lore.kernel.org/lkml/Y77%2FqVgvaJidFpYt@FVFF77S0Q05N110 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88345#c9111 */112#if defined(CONFIG_CC_HAS_SANE_FUNCTION_ALIGNMENT) || (CONFIG_FUNCTION_ALIGNMENT == 0)113#define __cold __attribute__((__cold__))114#else115#define __cold116#endif117 118/*119 * On x86-64 and arm64 targets, __preserve_most changes the calling convention120 * of a function to make the code in the caller as unintrusive as possible. This121 * convention behaves identically to the C calling convention on how arguments122 * 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 large126 * register set before and after the call in the caller. This is beneficial for127 * rarely taken slow paths, such as error-reporting functions that may be called128 * from hot paths.129 *130 * Note: This may conflict with instrumentation inserted on function entry which131 * does not use __preserve_most or equivalent convention (if in assembly). Since132 * function tracing assumes the normal C calling convention, where the attribute133 * is supported, __preserve_most implies notrace. It is recommended to restrict134 * 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-most139 */140#if __has_attribute(__preserve_most__) && (defined(CONFIG_X86_64) || defined(CONFIG_ARM64))141# define __preserve_most notrace __attribute__((__preserve_most__))142#else143# define __preserve_most144#endif145 146/*147 * Annotating a function/variable with __retain tells the compiler to place148 * the object in its own section and set the flag SHF_GNU_RETAIN. This flag149 * instructs the linker to retain the object during garbage-cleanup or LTO150 * phases.151 *152 * Note that the __used macro is also used to prevent functions or data153 * being optimized out, but operates at the compiler/IR-level and may still154 * allow unintended removal of objects during linking.155 *156 * Optional: only supported since gcc >= 11, clang >= 13157 *158 * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-retain-function-attribute159 * clang: https://clang.llvm.org/docs/AttributeReference.html#retain160 */161#if __has_attribute(__retain__) && \162 (defined(CONFIG_LD_DEAD_CODE_DATA_ELIMINATION) || \163 defined(CONFIG_LTO_CLANG))164# define __retain __attribute__((__retain__))165#else166# define __retain167#endif168 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#else176#error "Unknown compiler"177#endif178 179/*180 * Some architectures need to provide custom definitions of macros provided181 * by linux/compiler-*.h, and can do so using asm/compiler.h. We include that182 * conditionally rather than using an asm-generic wrapper in order to avoid183 * build failures if any C compilation, which will include this file via an184 * -include argument in c_flags, occurs prior to the asm-generic wrappers being185 * generated.186 */187#ifdef CONFIG_HAVE_ARCH_COMPILER_H188#include <asm/compiler.h>189#endif190 191struct 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 208struct 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#else218#define notrace __attribute__((__no_instrument_function__))219#endif220 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 without224 * stack and frame pointer being set up and there is no chance to225 * restore the lr register to the value before mcount was called.226 */227#define __naked __attribute__((__naked__)) notrace228 229/*230 * Prefer gnu_inline, so that extern inline functions do not emit an231 * externally visible function. This makes extern inline behave as per gnu89232 * semantics rather than c99. This prevents multiple symbol definition errors233 * 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 notrace237 238/*239 * gcc provides both __inline__ and __inline as alternate spellings of240 * the inline keyword, though the latter is undocumented. New kernel241 * code should only use the inline spelling, but some existing code242 * uses __inline__. Since we #define inline above, to ensure243 * __inline__ has the same semantics, we need this #define.244 *245 * However, the spelling __inline is strictly reserved for referring246 * to the bare keyword.247 */248#define __inline__ inline249 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 it253 * for W=1 build. This will allow clang to find unused functions. Remove the254 * __inline_maybe_unused entirely after fixing most of -Wunused-function warnings.255 */256#ifdef KBUILD_EXTRA_WARN1257#define __inline_maybe_unused258#else259#define __inline_maybe_unused __maybe_unused260#endif261 262/*263 * Rather then using noinline to prevent stack consumption, use264 * noinline_for_stack instead. For documentation reasons.265 */266#define noinline_for_stack noinline267 268/*269 * Sanitizer helper attributes: Because using __always_inline and270 * __no_sanitize_* conflict, provide helper attributes that will either expand271 * to __no_sanitize_* in compilation units where instrumentation is enabled272 * (__SANITIZE_*__), or __always_inline in compilation units without273 * instrumentation (__SANITIZE_*__ undefined).274 */275#ifdef __SANITIZE_ADDRESS__276/*277 * We can't declare function 'inline' because __no_sanitize_address conflicts278 * with inlining. Attempt to inline it may cause a build failure.279 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67368280 * '__maybe_unused' allows us to avoid defined-but-not-used warnings.281 */282# define __no_kasan_or_inline __no_sanitize_address notrace __maybe_unused283# define __no_sanitize_or_inline __no_kasan_or_inline284#else285# define __no_kasan_or_inline __always_inline286#endif287 288#ifdef __SANITIZE_THREAD__289/*290 * Clang still emits instrumentation for __tsan_func_{entry,exit}() and builtin291 * atomics even with __no_sanitize_thread (to avoid false positives in userspace292 * ThreadSanitizer). The kernel's requirements are stricter and we really do not293 * want any instrumentation with __no_kcsan.294 *295 * Therefore we add __disable_sanitizer_instrumentation where available to296 * disable all instrumentation. See Kconfig.kcsan where this is mandatory.297 */298# define __no_kcsan __no_sanitize_thread __disable_sanitizer_instrumentation299/*300 * Type qualifier to mark variables where all data-racy accesses should be301 * ignored by KCSAN. Note, the implementation simply marks these variables as302 * volatile, since KCSAN will treat such accesses as "marked".303 */304# define __data_racy volatile305# define __no_sanitize_or_inline __no_kcsan notrace __maybe_unused306#else307# define __no_kcsan308# define __data_racy309#endif310 311#ifdef __SANITIZE_MEMORY__312/*313 * Similarly to KASAN and KCSAN, KMSAN loses function attributes of inlined314 * functions, therefore disabling KMSAN checks also requires disabling inlining.315 *316 * __no_sanitize_or_inline effectively prevents KMSAN from reporting errors317 * within the function and marks all its outputs as initialized.318 */319# define __no_sanitize_or_inline __no_kmsan_checks notrace __maybe_unused320#endif321 322#ifndef __no_sanitize_or_inline323#define __no_sanitize_or_inline __always_inline324#endif325 326/*327 * Apply __counted_by() when the Endianness matches to increase test coverage.328 */329#ifdef __LITTLE_ENDIAN330#define __counted_by_le(member) __counted_by(member)331#define __counted_by_be(member)332#else333#define __counted_by_le(member)334#define __counted_by_be(member) __counted_by(member)335#endif336 337/* Do not trap wrapping arithmetic within an annotated function. */338#ifdef CONFIG_UBSAN_SIGNED_WRAP339# define __signed_wrap __attribute__((no_sanitize("signed-integer-overflow")))340#else341# define __signed_wrap342#endif343 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_wrap349 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 based356 * on it's instruction pointer. See cpu_in_idle().357 *358 * 2) supressing instrumentation around where cpuidle disables RCU; where the359 * function isn't strictly required for #1, this is interchangeable with360 * 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 above370 * 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_entropy374# define __latent_entropy375#endif376 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#else384# define __randomize_layout __designated_init385# define __no_randomize_layout386# define randomized_struct_fields_start387# define randomized_struct_fields_end388#endif389 390#ifndef __noscs391# define __noscs392#endif393 394#ifndef __nocfi395# define __nocfi396#endif397 398/*399 * Any place that could be marked with the "alloc_size" attribute is also400 * a place to be marked with the "malloc" attribute, except those that may401 * 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__) __malloc406# define __realloc_size(x, ...) __alloc_size__(x, ## __VA_ARGS__)407#else408# define __alloc_size(x, ...) __malloc409# define __realloc_size(x, ...)410#endif411 412/*413 * When the size of an allocated object is needed, use the best available414 * 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#else420#define __struct_size(p) __builtin_object_size(p, 0)421#define __member_size(p) __builtin_object_size(p, 1)422#endif423 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#else428#define __annotated(var, attr) (false)429#endif430 431/*432 * Some versions of gcc do not mark 'asm goto' volatile:433 *434 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103979435 *436 * We do it here by hand, because it doesn't hurt.437 */438#ifndef asm_goto_output439#define asm_goto_output(x...) asm volatile goto(x)440#endif441 442/*443 * Clang has trouble with constraints with multiple444 * alternative behaviors (mainly "g" and "rm").445 */446#ifndef ASM_INPUT_G447 #define ASM_INPUT_G "g"448 #define ASM_INPUT_RM "rm"449#endif450 451#ifdef CONFIG_CC_HAS_ASM_INLINE452#define asm_inline asm __inline453#else454#define asm_inline asm455#endif456 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, leaving462 * 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)0471 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#else501# define __compiletime_assert(condition, msg, prefix, suffix) do { } while (0)502#endif503 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 false509 * @condition: a compile-time constant condition to check510 * @msg: a message to emit if condition is false511 *512 * In tradition of POSIX assert, this macro will break the build if the513 * supplied condition is *false*, emitting the supplied error message if the514 * 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 __diag525#define __diag(string)526#endif527 528#ifndef __diag_GCC529#define __diag_GCC(version, severity, string)530#endif531 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_all543#define __diag_ignore_all(option, comment)544#endif545 546#endif /* __LINUX_COMPILER_TYPES_H */547