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Diffstat (limited to 'include/linux/compiler-gcc.h')
-rw-r--r-- | include/linux/compiler-gcc.h | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h new file mode 100644 index 000000000..f55a37efd --- /dev/null +++ b/include/linux/compiler-gcc.h @@ -0,0 +1,154 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __LINUX_COMPILER_TYPES_H +#error "Please don't include <linux/compiler-gcc.h> directly, include <linux/compiler.h> instead." +#endif + +/* + * Common definitions for all gcc versions go here. + */ +#define GCC_VERSION (__GNUC__ * 10000 \ + + __GNUC_MINOR__ * 100 \ + + __GNUC_PATCHLEVEL__) + +/* + * This macro obfuscates arithmetic on a variable address so that gcc + * shouldn't recognize the original var, and make assumptions about it. + * + * This is needed because the C standard makes it undefined to do + * pointer arithmetic on "objects" outside their boundaries and the + * gcc optimizers assume this is the case. In particular they + * assume such arithmetic does not wrap. + * + * A miscompilation has been observed because of this on PPC. + * To work around it we hide the relationship of the pointer and the object + * using this macro. + * + * Versions of the ppc64 compiler before 4.1 had a bug where use of + * RELOC_HIDE could trash r30. The bug can be worked around by changing + * the inline assembly constraint from =g to =r, in this particular + * case either is valid. + */ +#define RELOC_HIDE(ptr, off) \ +({ \ + unsigned long __ptr; \ + __asm__ ("" : "=r"(__ptr) : "0"(ptr)); \ + (typeof(ptr)) (__ptr + (off)); \ +}) + +#ifdef CONFIG_RETPOLINE +#define __noretpoline __attribute__((__indirect_branch__("keep"))) +#endif + +#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__) + +#if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__) +#define __latent_entropy __attribute__((latent_entropy)) +#endif + +/* + * calling noreturn functions, __builtin_unreachable() and __builtin_trap() + * confuse the stack allocation in gcc, leading to overly large stack + * frames, see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365 + * + * Adding an empty inline assembly before it works around the problem + */ +#define barrier_before_unreachable() asm volatile("") + +/* + * Mark a position in code as unreachable. This can be used to + * suppress control flow warnings after asm blocks that transfer + * control elsewhere. + */ +#define unreachable() \ + do { \ + annotate_unreachable(); \ + barrier_before_unreachable(); \ + __builtin_unreachable(); \ + } while (0) + +#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 GCC_VERSION >= 70000 +#define KASAN_ABI_VERSION 5 +#else +#define KASAN_ABI_VERSION 4 +#endif + +#ifdef CONFIG_SHADOW_CALL_STACK +#define __noscs __attribute__((__no_sanitize__("shadow-call-stack"))) +#endif + +#if __has_attribute(__no_sanitize_address__) +#define __no_sanitize_address __attribute__((no_sanitize_address)) +#else +#define __no_sanitize_address +#endif + +#if defined(__SANITIZE_THREAD__) && __has_attribute(__no_sanitize_thread__) +#define __no_sanitize_thread __attribute__((no_sanitize_thread)) +#else +#define __no_sanitize_thread +#endif + +#if __has_attribute(__no_sanitize_undefined__) +#define __no_sanitize_undefined __attribute__((no_sanitize_undefined)) +#else +#define __no_sanitize_undefined +#endif + +#if defined(CONFIG_KCOV) && __has_attribute(__no_sanitize_coverage__) +#define __no_sanitize_coverage __attribute__((no_sanitize_coverage)) +#else +#define __no_sanitize_coverage +#endif + +/* + * Treat __SANITIZE_HWADDRESS__ the same as __SANITIZE_ADDRESS__ in the kernel, + * matching the defines used by Clang. + */ +#ifdef __SANITIZE_HWADDRESS__ +#define __SANITIZE_ADDRESS__ +#endif + +/* + * GCC does not support KMSAN. + */ +#define __no_sanitize_memory +#define __no_kmsan_checks + +/* + * Turn individual warnings and errors on and off locally, depending + * on version. + */ +#define __diag_GCC(version, severity, s) \ + __diag_GCC_ ## version(__diag_GCC_ ## severity s) + +/* Severity used in pragma directives */ +#define __diag_GCC_ignore ignored +#define __diag_GCC_warn warning +#define __diag_GCC_error error + +#define __diag_str1(s) #s +#define __diag_str(s) __diag_str1(s) +#define __diag(s) _Pragma(__diag_str(GCC diagnostic s)) + +#if GCC_VERSION >= 80000 +#define __diag_GCC_8(s) __diag(s) +#else +#define __diag_GCC_8(s) +#endif + +#define __diag_ignore_all(option, comment) \ + __diag_GCC(8, ignore, option) + +/* + * Prior to 9.1, -Wno-alloc-size-larger-than (and therefore the "alloc_size" + * attribute) do not work, and must be disabled. + */ +#if GCC_VERSION < 90100 +#undef __alloc_size__ +#endif |