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 #elif defined(CONFIG_ARM64) && GCC_VERSION < 50100 17 /* 18 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63293 19 * https://lore.kernel.org/r/20210107111841.GN1551@shell.armlinux.org.uk 20 */ 21 # error Sorry, your version of GCC is too old - please use 5.1 or newer. 22 #endif 23 24 /* 25 * This macro obfuscates arithmetic on a variable address so that gcc 26 * shouldn't recognize the original var, and make assumptions about it. 27 * 28 * This is needed because the C standard makes it undefined to do 29 * pointer arithmetic on "objects" outside their boundaries and the 30 * gcc optimizers assume this is the case. In particular they 31 * assume such arithmetic does not wrap. 32 * 33 * A miscompilation has been observed because of this on PPC. 34 * To work around it we hide the relationship of the pointer and the object 35 * using this macro. 36 * 37 * Versions of the ppc64 compiler before 4.1 had a bug where use of 38 * RELOC_HIDE could trash r30. The bug can be worked around by changing 39 * the inline assembly constraint from =g to =r, in this particular 40 * case either is valid. 41 */ 42 #define RELOC_HIDE(ptr, off) \ 43 ({ \ 44 unsigned long __ptr; \ 45 __asm__ ("" : "=r"(__ptr) : "0"(ptr)); \ 46 (typeof(ptr)) (__ptr + (off)); \ 47 }) 48 49 #ifdef CONFIG_RETPOLINE 50 #define __noretpoline __attribute__((__indirect_branch__("keep"))) 51 #endif 52 53 #define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__) 54 55 #define __compiletime_object_size(obj) __builtin_object_size(obj, 0) 56 57 #if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__) 58 #define __latent_entropy __attribute__((latent_entropy)) 59 #endif 60 61 /* 62 * calling noreturn functions, __builtin_unreachable() and __builtin_trap() 63 * confuse the stack allocation in gcc, leading to overly large stack 64 * frames, see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365 65 * 66 * Adding an empty inline assembly before it works around the problem 67 */ 68 #define barrier_before_unreachable() asm volatile("") 69 70 /* 71 * Mark a position in code as unreachable. This can be used to 72 * suppress control flow warnings after asm blocks that transfer 73 * control elsewhere. 74 */ 75 #define unreachable() \ 76 do { \ 77 annotate_unreachable(); \ 78 barrier_before_unreachable(); \ 79 __builtin_unreachable(); \ 80 } while (0) 81 82 #if defined(RANDSTRUCT_PLUGIN) && !defined(__CHECKER__) 83 #define __randomize_layout __attribute__((randomize_layout)) 84 #define __no_randomize_layout __attribute__((no_randomize_layout)) 85 /* This anon struct can add padding, so only enable it under randstruct. */ 86 #define randomized_struct_fields_start struct { 87 #define randomized_struct_fields_end } __randomize_layout; 88 #endif 89 90 /* 91 * GCC 'asm goto' miscompiles certain code sequences: 92 * 93 * http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670 94 * 95 * Work it around via a compiler barrier quirk suggested by Jakub Jelinek. 96 * 97 * (asm goto is automatically volatile - the naming reflects this.) 98 */ 99 #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0) 100 101 /* 102 * sparse (__CHECKER__) pretends to be gcc, but can't do constant 103 * folding in __builtin_bswap*() (yet), so don't set these for it. 104 */ 105 #if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP) && !defined(__CHECKER__) 106 #define __HAVE_BUILTIN_BSWAP32__ 107 #define __HAVE_BUILTIN_BSWAP64__ 108 #define __HAVE_BUILTIN_BSWAP16__ 109 #endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP && !__CHECKER__ */ 110 111 #if GCC_VERSION >= 70000 112 #define KASAN_ABI_VERSION 5 113 #elif GCC_VERSION >= 50000 114 #define KASAN_ABI_VERSION 4 115 #elif GCC_VERSION >= 40902 116 #define KASAN_ABI_VERSION 3 117 #endif 118 119 #if __has_attribute(__no_sanitize_address__) 120 #define __no_sanitize_address __attribute__((no_sanitize_address)) 121 #else 122 #define __no_sanitize_address 123 #endif 124 125 #if defined(__SANITIZE_THREAD__) && __has_attribute(__no_sanitize_thread__) 126 #define __no_sanitize_thread __attribute__((no_sanitize_thread)) 127 #else 128 #define __no_sanitize_thread 129 #endif 130 131 #if __has_attribute(__no_sanitize_undefined__) 132 #define __no_sanitize_undefined __attribute__((no_sanitize_undefined)) 133 #else 134 #define __no_sanitize_undefined 135 #endif 136 137 #if defined(CONFIG_KCOV) && __has_attribute(__no_sanitize_coverage__) 138 #define __no_sanitize_coverage __attribute__((no_sanitize_coverage)) 139 #else 140 #define __no_sanitize_coverage 141 #endif 142 143 #if GCC_VERSION >= 50100 144 #define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1 145 #endif 146 147 /* 148 * Turn individual warnings and errors on and off locally, depending 149 * on version. 150 */ 151 #define __diag_GCC(version, severity, s) \ 152 __diag_GCC_ ## version(__diag_GCC_ ## severity s) 153 154 /* Severity used in pragma directives */ 155 #define __diag_GCC_ignore ignored 156 #define __diag_GCC_warn warning 157 #define __diag_GCC_error error 158 159 #define __diag_str1(s) #s 160 #define __diag_str(s) __diag_str1(s) 161 #define __diag(s) _Pragma(__diag_str(GCC diagnostic s)) 162 163 #if GCC_VERSION >= 80000 164 #define __diag_GCC_8(s) __diag(s) 165 #else 166 #define __diag_GCC_8(s) 167 #endif 168