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 #if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__) 43 #define __latent_entropy __attribute__((latent_entropy)) 44 #endif 45 46 /* 47 * calling noreturn functions, __builtin_unreachable() and __builtin_trap() 48 * confuse the stack allocation in gcc, leading to overly large stack 49 * frames, see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365 50 * 51 * Adding an empty inline assembly before it works around the problem 52 */ 53 #define barrier_before_unreachable() asm volatile("") 54 55 /* 56 * Mark a position in code as unreachable. This can be used to 57 * suppress control flow warnings after asm blocks that transfer 58 * control elsewhere. 59 */ 60 #define unreachable() \ 61 do { \ 62 annotate_unreachable(); \ 63 barrier_before_unreachable(); \ 64 __builtin_unreachable(); \ 65 } while (0) 66 67 /* 68 * GCC 'asm goto' with outputs miscompiles certain code sequences: 69 * 70 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110420 71 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110422 72 * 73 * Work it around via the same compiler barrier quirk that we used 74 * to use for the old 'asm goto' workaround. 75 * 76 * Also, always mark such 'asm goto' statements as volatile: all 77 * asm goto statements are supposed to be volatile as per the 78 * documentation, but some versions of gcc didn't actually do 79 * that for asms with outputs: 80 * 81 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98619 82 */ 83 #define asm_goto_output(x...) \ 84 do { asm volatile goto(x); asm (""); } while (0) 85 86 #if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP) 87 #define __HAVE_BUILTIN_BSWAP32__ 88 #define __HAVE_BUILTIN_BSWAP64__ 89 #define __HAVE_BUILTIN_BSWAP16__ 90 #endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */ 91 92 #if GCC_VERSION >= 70000 93 #define KASAN_ABI_VERSION 5 94 #else 95 #define KASAN_ABI_VERSION 4 96 #endif 97 98 #ifdef CONFIG_SHADOW_CALL_STACK 99 #define __noscs __attribute__((__no_sanitize__("shadow-call-stack"))) 100 #endif 101 102 #define __no_sanitize_address __attribute__((__no_sanitize_address__)) 103 104 #if defined(__SANITIZE_THREAD__) 105 #define __no_sanitize_thread __attribute__((__no_sanitize_thread__)) 106 #else 107 #define __no_sanitize_thread 108 #endif 109 110 #define __no_sanitize_undefined __attribute__((__no_sanitize_undefined__)) 111 112 /* 113 * Only supported since gcc >= 12 114 */ 115 #if defined(CONFIG_KCOV) && __has_attribute(__no_sanitize_coverage__) 116 #define __no_sanitize_coverage __attribute__((__no_sanitize_coverage__)) 117 #else 118 #define __no_sanitize_coverage 119 #endif 120 121 /* 122 * Treat __SANITIZE_HWADDRESS__ the same as __SANITIZE_ADDRESS__ in the kernel, 123 * matching the defines used by Clang. 124 */ 125 #ifdef __SANITIZE_HWADDRESS__ 126 #define __SANITIZE_ADDRESS__ 127 #endif 128 129 /* 130 * GCC does not support KMSAN. 131 */ 132 #define __no_sanitize_memory 133 #define __no_kmsan_checks 134 135 /* 136 * Turn individual warnings and errors on and off locally, depending 137 * on version. 138 */ 139 #define __diag_GCC(version, severity, s) \ 140 __diag_GCC_ ## version(__diag_GCC_ ## severity s) 141 142 /* Severity used in pragma directives */ 143 #define __diag_GCC_ignore ignored 144 #define __diag_GCC_warn warning 145 #define __diag_GCC_error error 146 147 #define __diag_str1(s) #s 148 #define __diag_str(s) __diag_str1(s) 149 #define __diag(s) _Pragma(__diag_str(GCC diagnostic s)) 150 151 #if GCC_VERSION >= 80000 152 #define __diag_GCC_8(s) __diag(s) 153 #else 154 #define __diag_GCC_8(s) 155 #endif 156 157 #define __diag_ignore_all(option, comment) \ 158 __diag(__diag_GCC_ignore option) 159 160 /* 161 * Prior to 9.1, -Wno-alloc-size-larger-than (and therefore the "alloc_size" 162 * attribute) do not work, and must be disabled. 163 */ 164 #if GCC_VERSION < 90100 165 #undef __alloc_size__ 166 #endif 167