/* SPDX-License-Identifier: GPL-2.0 */ #ifndef __LINUX_COMPILER_TYPES_H #define __LINUX_COMPILER_TYPES_H /* * __has_builtin is supported on gcc >= 10, clang >= 3 and icc >= 21. * In the meantime, to support gcc < 10, we implement __has_builtin * by hand. */ #ifndef __has_builtin #define __has_builtin(x) (0) #endif #ifndef __ASSEMBLY__ /* * Skipped when running bindgen due to a libclang issue; * see https://github.com/rust-lang/rust-bindgen/issues/2244. */ #if defined(CONFIG_DEBUG_INFO_BTF) && defined(CONFIG_PAHOLE_HAS_BTF_TAG) && \ __has_attribute(btf_type_tag) && !defined(__BINDGEN__) # define BTF_TYPE_TAG(value) __attribute__((btf_type_tag(#value))) #else # define BTF_TYPE_TAG(value) /* nothing */ #endif /* sparse defines __CHECKER__; see Documentation/dev-tools/sparse.rst */ #ifdef __CHECKER__ /* address spaces */ # define __kernel __attribute__((address_space(0))) # define __user __attribute__((noderef, address_space(__user))) # define __iomem __attribute__((noderef, address_space(__iomem))) # define __percpu __attribute__((noderef, address_space(__percpu))) # define __rcu __attribute__((noderef, address_space(__rcu))) static inline void __chk_user_ptr(const volatile void __user *ptr) { } static inline void __chk_io_ptr(const volatile void __iomem *ptr) { } /* context/locking */ # define __must_hold(x) __attribute__((context(x,1,1))) # define __acquires(x) __attribute__((context(x,0,1))) # define __cond_acquires(x) __attribute__((context(x,0,-1))) # define __releases(x) __attribute__((context(x,1,0))) # define __acquire(x) __context__(x,1) # define __release(x) __context__(x,-1) # define __cond_lock(x,c) ((c) ? ({ __acquire(x); 1; }) : 0) /* other */ # define __force __attribute__((force)) # define __nocast __attribute__((nocast)) # define __safe __attribute__((safe)) # define __private __attribute__((noderef)) # define ACCESS_PRIVATE(p, member) (*((typeof((p)->member) __force *) &(p)->member)) #else /* __CHECKER__ */ /* address spaces */ # define __kernel # ifdef STRUCTLEAK_PLUGIN # define __user __attribute__((user)) # else # define __user BTF_TYPE_TAG(user) # endif # define __iomem # define __percpu BTF_TYPE_TAG(percpu) # define __rcu BTF_TYPE_TAG(rcu) # define __chk_user_ptr(x) (void)0 # define __chk_io_ptr(x) (void)0 /* context/locking */ # define __must_hold(x) # define __acquires(x) # define __cond_acquires(x) # define __releases(x) # define __acquire(x) (void)0 # define __release(x) (void)0 # define __cond_lock(x,c) (c) /* other */ # define __force # define __nocast # define __safe # define __private # define ACCESS_PRIVATE(p, member) ((p)->member) # define __builtin_warning(x, y...) (1) #endif /* __CHECKER__ */ /* Indirect macros required for expanded argument pasting, eg. __LINE__. */ #define ___PASTE(a,b) a##b #define __PASTE(a,b) ___PASTE(a,b) #ifdef __KERNEL__ /* Attributes */ #include #if CONFIG_FUNCTION_ALIGNMENT > 0 #define __function_aligned __aligned(CONFIG_FUNCTION_ALIGNMENT) #else #define __function_aligned #endif /* * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-cold-function-attribute * gcc: https://gcc.gnu.org/onlinedocs/gcc/Label-Attributes.html#index-cold-label-attribute * * When -falign-functions=N is in use, we must avoid the cold attribute as * GCC drops the alignment for cold functions. Worse, GCC can implicitly mark * callees of cold functions as cold themselves, so it's not sufficient to add * __function_aligned here as that will not ensure that callees are correctly * aligned. * * See: * * https://lore.kernel.org/lkml/Y77%2FqVgvaJidFpYt@FVFF77S0Q05N * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88345#c9 */ #if defined(CONFIG_CC_HAS_SANE_FUNCTION_ALIGNMENT) || (CONFIG_FUNCTION_ALIGNMENT == 0) #define __cold __attribute__((__cold__)) #else #define __cold #endif /* * On x86-64 and arm64 targets, __preserve_most changes the calling convention * of a function to make the code in the caller as unintrusive as possible. This * convention behaves identically to the C calling convention on how arguments * and return values are passed, but uses a different set of caller- and callee- * saved registers. * * The purpose is to alleviates the burden of saving and recovering a large * register set before and after the call in the caller. This is beneficial for * rarely taken slow paths, such as error-reporting functions that may be called * from hot paths. * * Note: This may conflict with instrumentation inserted on function entry which * does not use __preserve_most or equivalent convention (if in assembly). Since * function tracing assumes the normal C calling convention, where the attribute * is supported, __preserve_most implies notrace. It is recommended to restrict * use of the attribute to functions that should or already disable tracing. * * Optional: not supported by gcc. * * clang: https://clang.llvm.org/docs/AttributeReference.html#preserve-most */ #if __has_attribute(__preserve_most__) && (defined(CONFIG_X86_64) || defined(CONFIG_ARM64)) # define __preserve_most notrace __attribute__((__preserve_most__)) #else # define __preserve_most #endif /* * Annotating a function/variable with __retain tells the compiler to place * the object in its own section and set the flag SHF_GNU_RETAIN. This flag * instructs the linker to retain the object during garbage-cleanup or LTO * phases. * * Note that the __used macro is also used to prevent functions or data * being optimized out, but operates at the compiler/IR-level and may still * allow unintended removal of objects during linking. * * Optional: only supported since gcc >= 11, clang >= 13 * * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-retain-function-attribute * clang: https://clang.llvm.org/docs/AttributeReference.html#retain */ #if __has_attribute(__retain__) && \ (defined(CONFIG_LD_DEAD_CODE_DATA_ELIMINATION) || \ defined(CONFIG_LTO_CLANG)) # define __retain __attribute__((__retain__)) #else # define __retain #endif /* Compiler specific macros. */ #ifdef __clang__ #include #elif defined(__GNUC__) /* The above compilers also define __GNUC__, so order is important here. */ #include #else #error "Unknown compiler" #endif /* * Some architectures need to provide custom definitions of macros provided * by linux/compiler-*.h, and can do so using asm/compiler.h. We include that * conditionally rather than using an asm-generic wrapper in order to avoid * build failures if any C compilation, which will include this file via an * -include argument in c_flags, occurs prior to the asm-generic wrappers being * generated. */ #ifdef CONFIG_HAVE_ARCH_COMPILER_H #include #endif struct ftrace_branch_data { const char *func; const char *file; unsigned line; union { struct { unsigned long correct; unsigned long incorrect; }; struct { unsigned long miss; unsigned long hit; }; unsigned long miss_hit[2]; }; }; struct ftrace_likely_data { struct ftrace_branch_data data; unsigned long constant; }; #if defined(CC_USING_HOTPATCH) #define notrace __attribute__((hotpatch(0, 0))) #elif defined(CC_USING_PATCHABLE_FUNCTION_ENTRY) #define notrace __attribute__((patchable_function_entry(0, 0))) #else #define notrace __attribute__((__no_instrument_function__)) #endif /* * it doesn't make sense on ARM (currently the only user of __naked) * to trace naked functions because then mcount is called without * stack and frame pointer being set up and there is no chance to * restore the lr register to the value before mcount was called. */ #define __naked __attribute__((__naked__)) notrace /* * Prefer gnu_inline, so that extern inline functions do not emit an * externally visible function. This makes extern inline behave as per gnu89 * semantics rather than c99. This prevents multiple symbol definition errors * of extern inline functions at link time. * A lot of inline functions can cause havoc with function tracing. */ #define inline inline __gnu_inline __inline_maybe_unused notrace /* * gcc provides both __inline__ and __inline as alternate spellings of * the inline keyword, though the latter is undocumented. New kernel * code should only use the inline spelling, but some existing code * uses __inline__. Since we #define inline above, to ensure * __inline__ has the same semantics, we need this #define. * * However, the spelling __inline is strictly reserved for referring * to the bare keyword. */ #define __inline__ inline /* * GCC does not warn about unused static inline functions for -Wunused-function. * Suppress the warning in clang as well by using __maybe_unused, but enable it * for W=1 build. This will allow clang to find unused functions. Remove the * __inline_maybe_unused entirely after fixing most of -Wunused-function warnings. */ #ifdef KBUILD_EXTRA_WARN1 #define __inline_maybe_unused #else #define __inline_maybe_unused __maybe_unused #endif /* * Rather then using noinline to prevent stack consumption, use * noinline_for_stack instead. For documentation reasons. */ #define noinline_for_stack noinline /* * Sanitizer helper attributes: Because using __always_inline and * __no_sanitize_* conflict, provide helper attributes that will either expand * to __no_sanitize_* in compilation units where instrumentation is enabled * (__SANITIZE_*__), or __always_inline in compilation units without * instrumentation (__SANITIZE_*__ undefined). */ #ifdef __SANITIZE_ADDRESS__ /* * We can't declare function 'inline' because __no_sanitize_address conflicts * with inlining. Attempt to inline it may cause a build failure. * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67368 * '__maybe_unused' allows us to avoid defined-but-not-used warnings. */ # define __no_kasan_or_inline __no_sanitize_address notrace __maybe_unused # define __no_sanitize_or_inline __no_kasan_or_inline #else # define __no_kasan_or_inline __always_inline #endif #ifdef __SANITIZE_THREAD__ /* * Clang still emits instrumentation for __tsan_func_{entry,exit}() and builtin * atomics even with __no_sanitize_thread (to avoid false positives in userspace * ThreadSanitizer). The kernel's requirements are stricter and we really do not * want any instrumentation with __no_kcsan. * * Therefore we add __disable_sanitizer_instrumentation where available to * disable all instrumentation. See Kconfig.kcsan where this is mandatory. */ # define __no_kcsan __no_sanitize_thread __disable_sanitizer_instrumentation /* * Type qualifier to mark variables where all data-racy accesses should be * ignored by KCSAN. Note, the implementation simply marks these variables as * volatile, since KCSAN will treat such accesses as "marked". */ # define __data_racy volatile # define __no_sanitize_or_inline __no_kcsan notrace __maybe_unused #else # define __no_kcsan # define __data_racy #endif #ifdef __SANITIZE_MEMORY__ /* * Similarly to KASAN and KCSAN, KMSAN loses function attributes of inlined * functions, therefore disabling KMSAN checks also requires disabling inlining. * * __no_sanitize_or_inline effectively prevents KMSAN from reporting errors * within the function and marks all its outputs as initialized. */ # define __no_sanitize_or_inline __no_kmsan_checks notrace __maybe_unused #endif #ifndef __no_sanitize_or_inline #define __no_sanitize_or_inline __always_inline #endif /* * Apply __counted_by() when the Endianness matches to increase test coverage. */ #ifdef __LITTLE_ENDIAN #define __counted_by_le(member) __counted_by(member) #define __counted_by_be(member) #else #define __counted_by_le(member) #define __counted_by_be(member) __counted_by(member) #endif /* Do not trap wrapping arithmetic within an annotated function. */ #ifdef CONFIG_UBSAN_SIGNED_WRAP # define __signed_wrap __attribute__((no_sanitize("signed-integer-overflow"))) #else # define __signed_wrap #endif /* Section for code which can't be instrumented at all */ #define __noinstr_section(section) \ noinline notrace __attribute((__section__(section))) \ __no_kcsan __no_sanitize_address __no_profile __no_sanitize_coverage \ __no_sanitize_memory __signed_wrap #define noinstr __noinstr_section(".noinstr.text") /* * The __cpuidle section is used twofold: * * 1) the original use -- identifying if a CPU is 'stuck' in idle state based * on it's instruction pointer. See cpu_in_idle(). * * 2) supressing instrumentation around where cpuidle disables RCU; where the * function isn't strictly required for #1, this is interchangeable with * noinstr. */ #define __cpuidle __noinstr_section(".cpuidle.text") #endif /* __KERNEL__ */ #endif /* __ASSEMBLY__ */ /* * The below symbols may be defined for one or more, but not ALL, of the above * compilers. We don't consider that to be an error, so set them to nothing. * For example, some of them are for compiler specific plugins. */ #ifndef __latent_entropy # define __latent_entropy #endif #if defined(RANDSTRUCT) && !defined(__CHECKER__) # define __randomize_layout __designated_init __attribute__((randomize_layout)) # define __no_randomize_layout __attribute__((no_randomize_layout)) /* This anon struct can add padding, so only enable it under randstruct. */ # define randomized_struct_fields_start struct { # define randomized_struct_fields_end } __randomize_layout; #else # define __randomize_layout __designated_init # define __no_randomize_layout # define randomized_struct_fields_start # define randomized_struct_fields_end #endif #ifndef __noscs # define __noscs #endif #ifndef __nocfi # define __nocfi #endif /* * Any place that could be marked with the "alloc_size" attribute is also * a place to be marked with the "malloc" attribute, except those that may * be performing a _reallocation_, as that may alias the existing pointer. * For these, use __realloc_size(). */ #ifdef __alloc_size__ # define __alloc_size(x, ...) __alloc_size__(x, ## __VA_ARGS__) __malloc # define __realloc_size(x, ...) __alloc_size__(x, ## __VA_ARGS__) #else # define __alloc_size(x, ...) __malloc # define __realloc_size(x, ...) #endif /* * When the size of an allocated object is needed, use the best available * mechanism to find it. (For cases where sizeof() cannot be used.) */ #if __has_builtin(__builtin_dynamic_object_size) #define __struct_size(p) __builtin_dynamic_object_size(p, 0) #define __member_size(p) __builtin_dynamic_object_size(p, 1) #else #define __struct_size(p) __builtin_object_size(p, 0) #define __member_size(p) __builtin_object_size(p, 1) #endif /* Determine if an attribute has been applied to a variable. */ #if __has_builtin(__builtin_has_attribute) #define __annotated(var, attr) __builtin_has_attribute(var, attr) #else #define __annotated(var, attr) (false) #endif /* * Some versions of gcc do not mark 'asm goto' volatile: * * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103979 * * We do it here by hand, because it doesn't hurt. */ #ifndef asm_goto_output #define asm_goto_output(x...) asm volatile goto(x) #endif /* * Clang has trouble with constraints with multiple * alternative behaviors (mainly "g" and "rm"). */ #ifndef ASM_INPUT_G #define ASM_INPUT_G "g" #define ASM_INPUT_RM "rm" #endif #ifdef CONFIG_CC_HAS_ASM_INLINE #define asm_inline asm __inline #else #define asm_inline asm #endif /* Are two types/vars the same type (ignoring qualifiers)? */ #define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b)) /* * __unqual_scalar_typeof(x) - Declare an unqualified scalar type, leaving * non-scalar types unchanged. */ /* * Prefer C11 _Generic for better compile-times and simpler code. Note: 'char' * is not type-compatible with 'signed char', and we define a separate case. */ #define __scalar_type_to_expr_cases(type) \ unsigned type: (unsigned type)0, \ signed type: (signed type)0 #define __unqual_scalar_typeof(x) typeof( \ _Generic((x), \ char: (char)0, \ __scalar_type_to_expr_cases(char), \ __scalar_type_to_expr_cases(short), \ __scalar_type_to_expr_cases(int), \ __scalar_type_to_expr_cases(long), \ __scalar_type_to_expr_cases(long long), \ default: (x))) /* Is this type a native word size -- useful for atomic operations */ #define __native_word(t) \ (sizeof(t) == sizeof(char) || sizeof(t) == sizeof(short) || \ sizeof(t) == sizeof(int) || sizeof(t) == sizeof(long)) #ifdef __OPTIMIZE__ # define __compiletime_assert(condition, msg, prefix, suffix) \ do { \ /* \ * __noreturn is needed to give the compiler enough \ * information to avoid certain possibly-uninitialized \ * warnings (regardless of the build failing). \ */ \ __noreturn extern void prefix ## suffix(void) \ __compiletime_error(msg); \ if (!(condition)) \ prefix ## suffix(); \ } while (0) #else # define __compiletime_assert(condition, msg, prefix, suffix) do { } while (0) #endif #define _compiletime_assert(condition, msg, prefix, suffix) \ __compiletime_assert(condition, msg, prefix, suffix) /** * compiletime_assert - break build and emit msg if condition is false * @condition: a compile-time constant condition to check * @msg: a message to emit if condition is false * * In tradition of POSIX assert, this macro will break the build if the * supplied condition is *false*, emitting the supplied error message if the * compiler has support to do so. */ #define compiletime_assert(condition, msg) \ _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) #define compiletime_assert_atomic_type(t) \ compiletime_assert(__native_word(t), \ "Need native word sized stores/loads for atomicity.") /* Helpers for emitting diagnostics in pragmas. */ #ifndef __diag #define __diag(string) #endif #ifndef __diag_GCC #define __diag_GCC(version, severity, string) #endif #define __diag_push() __diag(push) #define __diag_pop() __diag(pop) #define __diag_ignore(compiler, version, option, comment) \ __diag_ ## compiler(version, ignore, option) #define __diag_warn(compiler, version, option, comment) \ __diag_ ## compiler(version, warn, option) #define __diag_error(compiler, version, option, comment) \ __diag_ ## compiler(version, error, option) #ifndef __diag_ignore_all #define __diag_ignore_all(option, comment) #endif #endif /* __LINUX_COMPILER_TYPES_H */