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_RETPOLINE 39 #define __noretpoline __attribute__((__indirect_branch__("keep"))) 40 #endif 41 42 #define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__) 43 44 #define __compiletime_object_size(obj) __builtin_object_size(obj, 0) 45 46 #if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__) 47 #define __latent_entropy __attribute__((latent_entropy)) 48 #endif 49 50 /* 51 * calling noreturn functions, __builtin_unreachable() and __builtin_trap() 52 * confuse the stack allocation in gcc, leading to overly large stack 53 * frames, see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365 54 * 55 * Adding an empty inline assembly before it works around the problem 56 */ 57 #define barrier_before_unreachable() asm volatile("") 58 59 /* 60 * Mark a position in code as unreachable. This can be used to 61 * suppress control flow warnings after asm blocks that transfer 62 * control elsewhere. 63 */ 64 #define unreachable() \ 65 do { \ 66 annotate_unreachable(); \ 67 barrier_before_unreachable(); \ 68 __builtin_unreachable(); \ 69 } while (0) 70 71 #if defined(RANDSTRUCT_PLUGIN) && !defined(__CHECKER__) 72 #define __randomize_layout __attribute__((randomize_layout)) 73 #define __no_randomize_layout __attribute__((no_randomize_layout)) 74 /* This anon struct can add padding, so only enable it under randstruct. */ 75 #define randomized_struct_fields_start struct { 76 #define randomized_struct_fields_end } __randomize_layout; 77 #endif 78 79 /* 80 * GCC 'asm goto' miscompiles certain code sequences: 81 * 82 * http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670 83 * 84 * Work it around via a compiler barrier quirk suggested by Jakub Jelinek. 85 * 86 * (asm goto is automatically volatile - the naming reflects this.) 87 */ 88 #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0) 89 90 #if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP) 91 #define __HAVE_BUILTIN_BSWAP32__ 92 #define __HAVE_BUILTIN_BSWAP64__ 93 #define __HAVE_BUILTIN_BSWAP16__ 94 #endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */ 95 96 #if GCC_VERSION >= 70000 97 #define KASAN_ABI_VERSION 5 98 #elif GCC_VERSION >= 50000 99 #define KASAN_ABI_VERSION 4 100 #elif GCC_VERSION >= 40902 101 #define KASAN_ABI_VERSION 3 102 #endif 103 104 #if __has_attribute(__no_sanitize_address__) 105 #define __no_sanitize_address __attribute__((no_sanitize_address)) 106 #else 107 #define __no_sanitize_address 108 #endif 109 110 #if defined(__SANITIZE_THREAD__) && __has_attribute(__no_sanitize_thread__) 111 #define __no_sanitize_thread __attribute__((no_sanitize_thread)) 112 #else 113 #define __no_sanitize_thread 114 #endif 115 116 #if __has_attribute(__no_sanitize_undefined__) 117 #define __no_sanitize_undefined __attribute__((no_sanitize_undefined)) 118 #else 119 #define __no_sanitize_undefined 120 #endif 121 122 #if defined(CONFIG_KCOV) && __has_attribute(__no_sanitize_coverage__) 123 #define __no_sanitize_coverage __attribute__((no_sanitize_coverage)) 124 #else 125 #define __no_sanitize_coverage 126 #endif 127 128 #if GCC_VERSION >= 50100 129 #define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1 130 #endif 131 132 /* 133 * Turn individual warnings and errors on and off locally, depending 134 * on version. 135 */ 136 #define __diag_GCC(version, severity, s) \ 137 __diag_GCC_ ## version(__diag_GCC_ ## severity s) 138 139 /* Severity used in pragma directives */ 140 #define __diag_GCC_ignore ignored 141 #define __diag_GCC_warn warning 142 #define __diag_GCC_error error 143 144 #define __diag_str1(s) #s 145 #define __diag_str(s) __diag_str1(s) 146 #define __diag(s) _Pragma(__diag_str(GCC diagnostic s)) 147 148 #if GCC_VERSION >= 80000 149 #define __diag_GCC_8(s) __diag(s) 150 #else 151 #define __diag_GCC_8(s) 152 #endif 153