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 #define __compiletime_warning(message) __attribute__((__warning__(message))) 47 #define __compiletime_error(message) __attribute__((__error__(message))) 48 49 #if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__) 50 #define __latent_entropy __attribute__((latent_entropy)) 51 #endif 52 53 /* 54 * calling noreturn functions, __builtin_unreachable() and __builtin_trap() 55 * confuse the stack allocation in gcc, leading to overly large stack 56 * frames, see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365 57 * 58 * Adding an empty inline assembly before it works around the problem 59 */ 60 #define barrier_before_unreachable() asm volatile("") 61 62 /* 63 * Mark a position in code as unreachable. This can be used to 64 * suppress control flow warnings after asm blocks that transfer 65 * control elsewhere. 66 */ 67 #define unreachable() \ 68 do { \ 69 annotate_unreachable(); \ 70 barrier_before_unreachable(); \ 71 __builtin_unreachable(); \ 72 } while (0) 73 74 #if defined(RANDSTRUCT_PLUGIN) && !defined(__CHECKER__) 75 #define __randomize_layout __attribute__((randomize_layout)) 76 #define __no_randomize_layout __attribute__((no_randomize_layout)) 77 /* This anon struct can add padding, so only enable it under randstruct. */ 78 #define randomized_struct_fields_start struct { 79 #define randomized_struct_fields_end } __randomize_layout; 80 #endif 81 82 /* 83 * GCC 'asm goto' miscompiles certain code sequences: 84 * 85 * http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670 86 * 87 * Work it around via a compiler barrier quirk suggested by Jakub Jelinek. 88 * 89 * (asm goto is automatically volatile - the naming reflects this.) 90 */ 91 #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0) 92 93 /* 94 * sparse (__CHECKER__) pretends to be gcc, but can't do constant 95 * folding in __builtin_bswap*() (yet), so don't set these for it. 96 */ 97 #if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP) && !defined(__CHECKER__) 98 #define __HAVE_BUILTIN_BSWAP32__ 99 #define __HAVE_BUILTIN_BSWAP64__ 100 #define __HAVE_BUILTIN_BSWAP16__ 101 #endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP && !__CHECKER__ */ 102 103 #if GCC_VERSION >= 70000 104 #define KASAN_ABI_VERSION 5 105 #elif GCC_VERSION >= 50000 106 #define KASAN_ABI_VERSION 4 107 #elif GCC_VERSION >= 40902 108 #define KASAN_ABI_VERSION 3 109 #endif 110 111 #if __has_attribute(__no_sanitize_address__) 112 #define __no_sanitize_address __attribute__((no_sanitize_address)) 113 #else 114 #define __no_sanitize_address 115 #endif 116 117 #if defined(__SANITIZE_THREAD__) && __has_attribute(__no_sanitize_thread__) 118 #define __no_sanitize_thread __attribute__((no_sanitize_thread)) 119 #else 120 #define __no_sanitize_thread 121 #endif 122 123 #if __has_attribute(__no_sanitize_undefined__) 124 #define __no_sanitize_undefined __attribute__((no_sanitize_undefined)) 125 #else 126 #define __no_sanitize_undefined 127 #endif 128 129 #if GCC_VERSION >= 50100 130 #define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1 131 #endif 132 133 /* 134 * Turn individual warnings and errors on and off locally, depending 135 * on version. 136 */ 137 #define __diag_GCC(version, severity, s) \ 138 __diag_GCC_ ## version(__diag_GCC_ ## severity s) 139 140 /* Severity used in pragma directives */ 141 #define __diag_GCC_ignore ignored 142 #define __diag_GCC_warn warning 143 #define __diag_GCC_error error 144 145 #define __diag_str1(s) #s 146 #define __diag_str(s) __diag_str1(s) 147 #define __diag(s) _Pragma(__diag_str(GCC diagnostic s)) 148 149 #if GCC_VERSION >= 80000 150 #define __diag_GCC_8(s) __diag(s) 151 #else 152 #define __diag_GCC_8(s) 153 #endif 154