1/* SPDX-License-Identifier: GPL-2.0 */ 2#ifndef __LINUX_COMPILER_TYPES_H 3#error "Please don't include <linux/compiler-gcc.h> directly, include <linux/compiler.h> instead." 4#endif 5 6/* 7 * Common definitions for all gcc versions go here. 8 */ 9#define GCC_VERSION (__GNUC__ * 10000 \ 10 + __GNUC_MINOR__ * 100 \ 11 + __GNUC_PATCHLEVEL__) 12 13/* 14 * This macro obfuscates arithmetic on a variable address so that gcc 15 * shouldn't recognize the original var, and make assumptions about it. 16 * 17 * This is needed because the C standard makes it undefined to do 18 * pointer arithmetic on "objects" outside their boundaries and the 19 * gcc optimizers assume this is the case. In particular they 20 * assume such arithmetic does not wrap. 21 * 22 * A miscompilation has been observed because of this on PPC. 23 * To work around it we hide the relationship of the pointer and the object 24 * using this macro. 25 * 26 * Versions of the ppc64 compiler before 4.1 had a bug where use of 27 * RELOC_HIDE could trash r30. The bug can be worked around by changing 28 * the inline assembly constraint from =g to =r, in this particular 29 * case either is valid. 30 */ 31#define RELOC_HIDE(ptr, off) \ 32({ \ 33 unsigned long __ptr; \ 34 __asm__ ("" : "=r"(__ptr) : "0"(ptr)); \ 35 (typeof(ptr)) (__ptr + (off)); \ 36}) 37 38#ifdef CONFIG_MITIGATION_RETPOLINE 39#define __noretpoline __attribute__((__indirect_branch__("keep"))) 40#endif 41 42#if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__) 43#define __latent_entropy __attribute__((latent_entropy)) 44#endif 45 46/* 47 * calling noreturn functions, __builtin_unreachable() and __builtin_trap() 48 * confuse the stack allocation in gcc, leading to overly large stack 49 * frames, see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365 50 * 51 * Adding an empty inline assembly before it works around the problem 52 */ 53#define barrier_before_unreachable() asm volatile("") 54 55/* 56 * Mark a position in code as unreachable. This can be used to 57 * suppress control flow warnings after asm blocks that transfer 58 * control elsewhere. 59 */ 60#define unreachable() \ 61 do { \ 62 annotate_unreachable(); \ 63 barrier_before_unreachable(); \ 64 __builtin_unreachable(); \ 65 } while (0) 66 67/* 68 * GCC 'asm goto' with outputs miscompiles certain code sequences: 69 * 70 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113921 71 * 72 * Work around it via the same compiler barrier quirk that we used 73 * to use for the old 'asm goto' workaround. 74 * 75 * Also, always mark such 'asm goto' statements as volatile: all 76 * asm goto statements are supposed to be volatile as per the 77 * documentation, but some versions of gcc didn't actually do 78 * that for asms with outputs: 79 * 80 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98619 81 */ 82#ifdef CONFIG_GCC_ASM_GOTO_OUTPUT_WORKAROUND 83#define asm_goto_output(x...) \ 84 do { asm volatile goto(x); asm (""); } while (0) 85#endif 86 87#if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP) 88#define __HAVE_BUILTIN_BSWAP32__ 89#define __HAVE_BUILTIN_BSWAP64__ 90#define __HAVE_BUILTIN_BSWAP16__ 91#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */ 92 93#if GCC_VERSION >= 70000 94#define KASAN_ABI_VERSION 5 95#else 96#define KASAN_ABI_VERSION 4 97#endif 98 99#ifdef CONFIG_SHADOW_CALL_STACK 100#define __noscs __attribute__((__no_sanitize__("shadow-call-stack"))) 101#endif 102 103#define __no_sanitize_address __attribute__((__no_sanitize_address__)) 104 105#if defined(__SANITIZE_THREAD__) 106#define __no_sanitize_thread __attribute__((__no_sanitize_thread__)) 107#else 108#define __no_sanitize_thread 109#endif 110 111#define __no_sanitize_undefined __attribute__((__no_sanitize_undefined__)) 112 113/* 114 * Only supported since gcc >= 12 115 */ 116#if defined(CONFIG_KCOV) && __has_attribute(__no_sanitize_coverage__) 117#define __no_sanitize_coverage __attribute__((__no_sanitize_coverage__)) 118#else 119#define __no_sanitize_coverage 120#endif 121 122/* 123 * Treat __SANITIZE_HWADDRESS__ the same as __SANITIZE_ADDRESS__ in the kernel, 124 * matching the defines used by Clang. 125 */ 126#ifdef __SANITIZE_HWADDRESS__ 127#define __SANITIZE_ADDRESS__ 128#endif 129 130/* 131 * GCC does not support KMSAN. 132 */ 133#define __no_sanitize_memory 134#define __no_kmsan_checks 135 136/* 137 * Turn individual warnings and errors on and off locally, depending 138 * on version. 139 */ 140#define __diag_GCC(version, severity, s) \ 141 __diag_GCC_ ## version(__diag_GCC_ ## severity s) 142 143/* Severity used in pragma directives */ 144#define __diag_GCC_ignore ignored 145#define __diag_GCC_warn warning 146#define __diag_GCC_error error 147 148#define __diag_str1(s) #s 149#define __diag_str(s) __diag_str1(s) 150#define __diag(s) _Pragma(__diag_str(GCC diagnostic s)) 151 152#if GCC_VERSION >= 80000 153#define __diag_GCC_8(s) __diag(s) 154#else 155#define __diag_GCC_8(s) 156#endif 157 158#define __diag_ignore_all(option, comment) \ 159 __diag(__diag_GCC_ignore option) 160 161/* 162 * Prior to 9.1, -Wno-alloc-size-larger-than (and therefore the "alloc_size" 163 * attribute) do not work, and must be disabled. 164 */ 165#if GCC_VERSION < 90100 166#undef __alloc_size__ 167#endif 168