diff options
Diffstat (limited to 'include/linux/compiler-clang.h')
| -rw-r--r-- | include/linux/compiler-clang.h | 109 |
1 files changed, 92 insertions, 17 deletions
diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h index cee0c728d39a..4fc8e26914ad 100644 --- a/include/linux/compiler-clang.h +++ b/include/linux/compiler-clang.h @@ -1,18 +1,28 @@ /* SPDX-License-Identifier: GPL-2.0 */ #ifndef __LINUX_COMPILER_TYPES_H -#error "Please don't include <linux/compiler-clang.h> directly, include <linux/compiler.h> instead." +#error "Please do not include <linux/compiler-clang.h> directly, include <linux/compiler.h> instead." #endif /* Compiler specific definitions for Clang compiler */ -/* same as gcc, this was present in clang-2.6 so we can assume it works - * with any version that can compile the kernel +/* + * Clang prior to 17 is being silly and considers many __cleanup() variables + * as unused (because they are, their sole purpose is to go out of scope). + * + * https://github.com/llvm/llvm-project/commit/877210faa447f4cc7db87812f8ed80e398fedd61 */ -#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__) +#undef __cleanup +#define __cleanup(func) __maybe_unused __attribute__((__cleanup__(func))) /* all clang versions usable with the kernel support KASAN ABI version 5 */ #define KASAN_ABI_VERSION 5 +/* + * Note: Checking __has_feature(*_sanitizer) is only true if the feature is + * enabled. Therefore it is not required to additionally check defined(CONFIG_*) + * to avoid adding redundant attributes in other configurations. + */ + #if __has_feature(address_sanitizer) || __has_feature(hwaddress_sanitizer) /* Emulate GCC's __SANITIZE_ADDRESS__ flag */ #define __SANITIZE_ADDRESS__ @@ -31,6 +41,12 @@ #define __no_sanitize_thread #endif +#if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP) +#define __HAVE_BUILTIN_BSWAP32__ +#define __HAVE_BUILTIN_BSWAP64__ +#define __HAVE_BUILTIN_BSWAP16__ +#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */ + #if __has_feature(undefined_behavior_sanitizer) /* GCC does not have __SANITIZE_UNDEFINED__ */ #define __no_sanitize_undefined \ @@ -39,25 +55,84 @@ #define __no_sanitize_undefined #endif +#if __has_feature(memory_sanitizer) +#define __SANITIZE_MEMORY__ +/* + * Unlike other sanitizers, KMSAN still inserts code into functions marked with + * no_sanitize("kernel-memory"). Using disable_sanitizer_instrumentation + * provides the behavior consistent with other __no_sanitize_ attributes, + * guaranteeing that __no_sanitize_memory functions remain uninstrumented. + */ +#define __no_sanitize_memory __disable_sanitizer_instrumentation + /* - * Not all versions of clang implement the type-generic versions - * of the builtin overflow checkers. Fortunately, clang implements - * __has_builtin allowing us to avoid awkward version - * checks. Unfortunately, we don't know which version of gcc clang - * pretends to be, so the macro may or may not be defined. + * The __no_kmsan_checks attribute ensures that a function does not produce + * false positive reports by: + * - initializing all local variables and memory stores in this function; + * - skipping all shadow checks; + * - passing initialized arguments to this function's callees. */ -#if __has_builtin(__builtin_mul_overflow) && \ - __has_builtin(__builtin_add_overflow) && \ - __has_builtin(__builtin_sub_overflow) -#define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1 +#define __no_kmsan_checks __attribute__((no_sanitize("kernel-memory"))) +#else +#define __no_sanitize_memory +#define __no_kmsan_checks #endif -/* The following are for compatibility with GCC, from compiler-gcc.h, - * and may be redefined here because they should not be shared with other - * compilers, like ICC. +/* + * Support for __has_feature(coverage_sanitizer) was added in Clang 13 together + * with no_sanitize("coverage"). Prior versions of Clang support coverage + * instrumentation, but cannot be queried for support by the preprocessor. */ -#define barrier() __asm__ __volatile__("" : : : "memory") +#if __has_feature(coverage_sanitizer) +#define __no_sanitize_coverage __attribute__((no_sanitize("coverage"))) +#else +#define __no_sanitize_coverage +#endif #if __has_feature(shadow_call_stack) # define __noscs __attribute__((__no_sanitize__("shadow-call-stack"))) #endif + +#if __has_feature(kcfi) +/* Disable CFI checking inside a function. */ +#define __nocfi __attribute__((__no_sanitize__("kcfi"))) +#endif + +/* + * Turn individual warnings and errors on and off locally, depending + * on version. + */ +#define __diag_clang(version, severity, s) \ + __diag_clang_ ## version(__diag_clang_ ## severity s) + +/* Severity used in pragma directives */ +#define __diag_clang_ignore ignored +#define __diag_clang_warn warning +#define __diag_clang_error error + +#define __diag_str1(s) #s +#define __diag_str(s) __diag_str1(s) +#define __diag(s) _Pragma(__diag_str(clang diagnostic s)) + +#define __diag_clang_13(s) __diag(s) + +#define __diag_ignore_all(option, comment) \ + __diag_clang(13, ignore, option) + +/* + * clang has horrible behavior with "g" or "rm" constraints for asm + * inputs, turning them into something worse than "m". Avoid using + * constraints with multiple possible uses (but "ir" seems to be ok): + * + * https://github.com/llvm/llvm-project/issues/20571 + */ +#define ASM_INPUT_G "ir" +#define ASM_INPUT_RM "r" + +/* + * Declare compiler support for __typeof_unqual__() operator. + * + * Bindgen uses LLVM even if our C compiler is GCC, so we cannot + * rely on the auto-detected CONFIG_CC_HAS_TYPEOF_UNQUAL. + */ +#define CC_HAS_TYPEOF_UNQUAL (__clang_major__ >= 19) |