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 /* https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145 */ 14 #if GCC_VERSION < 40900 15 # error Sorry, your version of GCC is too old - please use 4.9 or newer. 16 #endif 17 18 /* 19 * This macro obfuscates arithmetic on a variable address so that gcc 20 * shouldn't recognize the original var, and make assumptions about it. 21 * 22 * This is needed because the C standard makes it undefined to do 23 * pointer arithmetic on "objects" outside their boundaries and the 24 * gcc optimizers assume this is the case. In particular they 25 * assume such arithmetic does not wrap. 26 * 27 * A miscompilation has been observed because of this on PPC. 28 * To work around it we hide the relationship of the pointer and the object 29 * using this macro. 30 * 31 * Versions of the ppc64 compiler before 4.1 had a bug where use of 32 * RELOC_HIDE could trash r30. The bug can be worked around by changing 33 * the inline assembly constraint from =g to =r, in this particular 34 * case either is valid. 35 */ 36 #define RELOC_HIDE(ptr, off) \ 37 ({ \ 38 unsigned long __ptr; \ 39 __asm__ ("" : "=r"(__ptr) : "0"(ptr)); \ 40 (typeof(ptr)) (__ptr + (off)); \ 41 }) 42 43 #ifdef CONFIG_RETPOLINE 44 #define __noretpoline __attribute__((__indirect_branch__("keep"))) 45 #endif 46 47 #define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__) 48 49 #define __compiletime_object_size(obj) __builtin_object_size(obj, 0) 50 51 #define __compiletime_warning(message) __attribute__((__warning__(message))) 52 #define __compiletime_error(message) __attribute__((__error__(message))) 53 54 #if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__) 55 #define __latent_entropy __attribute__((latent_entropy)) 56 #endif 57 58 /* 59 * calling noreturn functions, __builtin_unreachable() and __builtin_trap() 60 * confuse the stack allocation in gcc, leading to overly large stack 61 * frames, see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365 62 * 63 * Adding an empty inline assembly before it works around the problem 64 */ 65 #define barrier_before_unreachable() asm volatile("") 66 67 /* 68 * Mark a position in code as unreachable. This can be used to 69 * suppress control flow warnings after asm blocks that transfer 70 * control elsewhere. 71 */ 72 #define unreachable() \ 73 do { \ 74 annotate_unreachable(); \ 75 barrier_before_unreachable(); \ 76 __builtin_unreachable(); \ 77 } while (0) 78 79 #if defined(RANDSTRUCT_PLUGIN) && !defined(__CHECKER__) 80 #define __randomize_layout __attribute__((randomize_layout)) 81 #define __no_randomize_layout __attribute__((no_randomize_layout)) 82 /* This anon struct can add padding, so only enable it under randstruct. */ 83 #define randomized_struct_fields_start struct { 84 #define randomized_struct_fields_end } __randomize_layout; 85 #endif 86 87 /* 88 * GCC 'asm goto' miscompiles certain code sequences: 89 * 90 * http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670 91 * 92 * Work it around via a compiler barrier quirk suggested by Jakub Jelinek. 93 * 94 * (asm goto is automatically volatile - the naming reflects this.) 95 */ 96 #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0) 97 98 /* 99 * sparse (__CHECKER__) pretends to be gcc, but can't do constant 100 * folding in __builtin_bswap*() (yet), so don't set these for it. 101 */ 102 #if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP) && !defined(__CHECKER__) 103 #define __HAVE_BUILTIN_BSWAP32__ 104 #define __HAVE_BUILTIN_BSWAP64__ 105 #define __HAVE_BUILTIN_BSWAP16__ 106 #endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP && !__CHECKER__ */ 107 108 #if GCC_VERSION >= 70000 109 #define KASAN_ABI_VERSION 5 110 #elif GCC_VERSION >= 50000 111 #define KASAN_ABI_VERSION 4 112 #elif GCC_VERSION >= 40902 113 #define KASAN_ABI_VERSION 3 114 #endif 115 116 #if __has_attribute(__no_sanitize_address__) 117 #define __no_sanitize_address __attribute__((no_sanitize_address)) 118 #else 119 #define __no_sanitize_address 120 #endif 121 122 #if defined(__SANITIZE_THREAD__) && __has_attribute(__no_sanitize_thread__) 123 #define __no_sanitize_thread __attribute__((no_sanitize_thread)) 124 #else 125 #define __no_sanitize_thread 126 #endif 127 128 #if __has_attribute(__no_sanitize_undefined__) 129 #define __no_sanitize_undefined __attribute__((no_sanitize_undefined)) 130 #else 131 #define __no_sanitize_undefined 132 #endif 133 134 #if GCC_VERSION >= 50100 135 #define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1 136 #endif 137 138 /* 139 * Turn individual warnings and errors on and off locally, depending 140 * on version. 141 */ 142 #define __diag_GCC(version, severity, s) \ 143 __diag_GCC_ ## version(__diag_GCC_ ## severity s) 144 145 /* Severity used in pragma directives */ 146 #define __diag_GCC_ignore ignored 147 #define __diag_GCC_warn warning 148 #define __diag_GCC_error error 149 150 #define __diag_str1(s) #s 151 #define __diag_str(s) __diag_str1(s) 152 #define __diag(s) _Pragma(__diag_str(GCC diagnostic s)) 153 154 #if GCC_VERSION >= 80000 155 #define __diag_GCC_8(s) __diag(s) 156 #else 157 #define __diag_GCC_8(s) 158 #endif 159
