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 #if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__) 45 #define __latent_entropy __attribute__((latent_entropy)) 46 #endif 47 48 /* 49 * calling noreturn functions, __builtin_unreachable() and __builtin_trap() 50 * confuse the stack allocation in gcc, leading to overly large stack 51 * frames, see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365 52 * 53 * Adding an empty inline assembly before it works around the problem 54 */ 55 #define barrier_before_unreachable() asm volatile("") 56 57 /* 58 * Mark a position in code as unreachable. This can be used to 59 * suppress control flow warnings after asm blocks that transfer 60 * control elsewhere. 61 */ 62 #define unreachable() \ 63 do { \ 64 annotate_unreachable(); \ 65 barrier_before_unreachable(); \ 66 __builtin_unreachable(); \ 67 } while (0) 68 69 #if defined(RANDSTRUCT_PLUGIN) && !defined(__CHECKER__) 70 #define __randomize_layout __attribute__((randomize_layout)) 71 #define __no_randomize_layout __attribute__((no_randomize_layout)) 72 /* This anon struct can add padding, so only enable it under randstruct. */ 73 #define randomized_struct_fields_start struct { 74 #define randomized_struct_fields_end } __randomize_layout; 75 #endif 76 77 /* 78 * GCC 'asm goto' miscompiles certain code sequences: 79 * 80 * http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670 81 * 82 * Work it around via a compiler barrier quirk suggested by Jakub Jelinek. 83 * 84 * (asm goto is automatically volatile - the naming reflects this.) 85 */ 86 #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0) 87 88 #if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP) 89 #define __HAVE_BUILTIN_BSWAP32__ 90 #define __HAVE_BUILTIN_BSWAP64__ 91 #define __HAVE_BUILTIN_BSWAP16__ 92 #endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */ 93 94 #if GCC_VERSION >= 70000 95 #define KASAN_ABI_VERSION 5 96 #else 97 #define KASAN_ABI_VERSION 4 98 #endif 99 100 #ifdef CONFIG_SHADOW_CALL_STACK 101 #define __noscs __attribute__((__no_sanitize__("shadow-call-stack"))) 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 /* 129 * Treat __SANITIZE_HWADDRESS__ the same as __SANITIZE_ADDRESS__ in the kernel, 130 * matching the defines used by Clang. 131 */ 132 #ifdef __SANITIZE_HWADDRESS__ 133 #define __SANITIZE_ADDRESS__ 134 #endif 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_GCC(8, 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