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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
d1515582 | 2 | #ifndef __LINUX_COMPILER_TYPES_H |
94f582f8 RD |
3 | #error "Please don't include <linux/compiler-gcc.h> directly, include <linux/compiler.h> instead." |
4 | #endif | |
1da177e4 LT |
5 | |
6 | /* | |
7 | * Common definitions for all gcc versions go here. | |
8 | */ | |
f6d133f8 JP |
9 | #define GCC_VERSION (__GNUC__ * 10000 \ |
10 | + __GNUC_MINOR__ * 100 \ | |
11 | + __GNUC_PATCHLEVEL__) | |
1da177e4 | 12 | |
5429ef62 WD |
13 | /* https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145 */ |
14 | #if GCC_VERSION < 40800 | |
cafa0010 JP |
15 | # error Sorry, your compiler is too old - please upgrade it. |
16 | #endif | |
17 | ||
1da177e4 | 18 | /* Optimization barrier */ |
7829fb09 | 19 | |
1da177e4 LT |
20 | /* The "volatile" is due to gcc bugs */ |
21 | #define barrier() __asm__ __volatile__("": : :"memory") | |
7829fb09 DB |
22 | /* |
23 | * This version is i.e. to prevent dead stores elimination on @ptr | |
24 | * where gcc and llvm may behave differently when otherwise using | |
25 | * normal barrier(): while gcc behavior gets along with a normal | |
26 | * barrier(), llvm needs an explicit input variable to be assumed | |
27 | * clobbered. The issue is as follows: while the inline asm might | |
28 | * access any memory it wants, the compiler could have fit all of | |
29 | * @ptr into memory registers instead, and since @ptr never escaped | |
8e8780a5 | 30 | * from that, it proved that the inline asm wasn't touching any of |
7829fb09 DB |
31 | * it. This version works well with both compilers, i.e. we're telling |
32 | * the compiler that the inline asm absolutely may see the contents | |
33 | * of @ptr. See also: https://llvm.org/bugs/show_bug.cgi?id=15495 | |
34 | */ | |
35 | #define barrier_data(ptr) __asm__ __volatile__("": :"r"(ptr) :"memory") | |
1da177e4 | 36 | |
c8d52465 | 37 | /* |
85c210ed AK |
38 | * This macro obfuscates arithmetic on a variable address so that gcc |
39 | * shouldn't recognize the original var, and make assumptions about it. | |
40 | * | |
41 | * This is needed because the C standard makes it undefined to do | |
42 | * pointer arithmetic on "objects" outside their boundaries and the | |
43 | * gcc optimizers assume this is the case. In particular they | |
44 | * assume such arithmetic does not wrap. | |
45 | * | |
46 | * A miscompilation has been observed because of this on PPC. | |
47 | * To work around it we hide the relationship of the pointer and the object | |
48 | * using this macro. | |
49 | * | |
c8d52465 AB |
50 | * Versions of the ppc64 compiler before 4.1 had a bug where use of |
51 | * RELOC_HIDE could trash r30. The bug can be worked around by changing | |
52 | * the inline assembly constraint from =g to =r, in this particular | |
53 | * case either is valid. | |
54 | */ | |
f6d133f8 JP |
55 | #define RELOC_HIDE(ptr, off) \ |
56 | ({ \ | |
57 | unsigned long __ptr; \ | |
58 | __asm__ ("" : "=r"(__ptr) : "0"(ptr)); \ | |
59 | (typeof(ptr)) (__ptr + (off)); \ | |
60 | }) | |
a1365647 | 61 | |
cafa0010 JP |
62 | /* |
63 | * A trick to suppress uninitialized variable warning without generating any | |
64 | * code | |
65 | */ | |
66 | #define uninitialized_var(x) x = x | |
67 | ||
e4f35891 | 68 | #ifdef CONFIG_RETPOLINE |
5c67a52f | 69 | #define __noretpoline __attribute__((__indirect_branch__("keep"))) |
87358710 DW |
70 | #endif |
71 | ||
cb984d10 JP |
72 | #define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__) |
73 | ||
cafa0010 | 74 | #define __compiletime_object_size(obj) __builtin_object_size(obj, 0) |
0766f788 | 75 | |
5c67a52f MO |
76 | #define __compiletime_warning(message) __attribute__((__warning__(message))) |
77 | #define __compiletime_error(message) __attribute__((__error__(message))) | |
cafa0010 | 78 | |
989bd500 | 79 | #if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__) |
0766f788 ER |
80 | #define __latent_entropy __attribute__((latent_entropy)) |
81 | #endif | |
0766f788 | 82 | |
173a3efd AB |
83 | /* |
84 | * calling noreturn functions, __builtin_unreachable() and __builtin_trap() | |
85 | * confuse the stack allocation in gcc, leading to overly large stack | |
86 | * frames, see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365 | |
87 | * | |
88 | * Adding an empty inline assembly before it works around the problem | |
89 | */ | |
90 | #define barrier_before_unreachable() asm volatile("") | |
91 | ||
cb984d10 JP |
92 | /* |
93 | * Mark a position in code as unreachable. This can be used to | |
94 | * suppress control flow warnings after asm blocks that transfer | |
95 | * control elsewhere. | |
cb984d10 | 96 | */ |
4e4636cf | 97 | #define unreachable() \ |
173a3efd AB |
98 | do { \ |
99 | annotate_unreachable(); \ | |
100 | barrier_before_unreachable(); \ | |
101 | __builtin_unreachable(); \ | |
102 | } while (0) | |
cb984d10 | 103 | |
a3d6c976 | 104 | #if defined(RANDSTRUCT_PLUGIN) && !defined(__CHECKER__) |
313dd1b6 KC |
105 | #define __randomize_layout __attribute__((randomize_layout)) |
106 | #define __no_randomize_layout __attribute__((no_randomize_layout)) | |
2cfe0d30 KC |
107 | /* This anon struct can add padding, so only enable it under randstruct. */ |
108 | #define randomized_struct_fields_start struct { | |
109 | #define randomized_struct_fields_end } __randomize_layout; | |
313dd1b6 KC |
110 | #endif |
111 | ||
cb984d10 JP |
112 | /* |
113 | * GCC 'asm goto' miscompiles certain code sequences: | |
114 | * | |
115 | * http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670 | |
116 | * | |
117 | * Work it around via a compiler barrier quirk suggested by Jakub Jelinek. | |
118 | * | |
119 | * (asm goto is automatically volatile - the naming reflects this.) | |
120 | */ | |
121 | #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0) | |
122 | ||
101b29a2 JB |
123 | /* |
124 | * sparse (__CHECKER__) pretends to be gcc, but can't do constant | |
125 | * folding in __builtin_bswap*() (yet), so don't set these for it. | |
126 | */ | |
127 | #if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP) && !defined(__CHECKER__) | |
cb984d10 JP |
128 | #define __HAVE_BUILTIN_BSWAP32__ |
129 | #define __HAVE_BUILTIN_BSWAP64__ | |
cb984d10 | 130 | #define __HAVE_BUILTIN_BSWAP16__ |
101b29a2 | 131 | #endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP && !__CHECKER__ */ |
cb984d10 | 132 | |
045d599a DV |
133 | #if GCC_VERSION >= 70000 |
134 | #define KASAN_ABI_VERSION 5 | |
135 | #elif GCC_VERSION >= 50000 | |
cb984d10 JP |
136 | #define KASAN_ABI_VERSION 4 |
137 | #elif GCC_VERSION >= 40902 | |
138 | #define KASAN_ABI_VERSION 3 | |
139 | #endif | |
140 | ||
2bd926b4 AK |
141 | #if __has_attribute(__no_sanitize_address__) |
142 | #define __no_sanitize_address __attribute__((no_sanitize_address)) | |
143 | #else | |
144 | #define __no_sanitize_address | |
145 | #endif | |
146 | ||
dfd402a4 | 147 | #if defined(__SANITIZE_THREAD__) && __has_attribute(__no_sanitize_thread__) |
e33f9a16 | 148 | #define __no_sanitize_thread __attribute__((no_sanitize_thread)) |
dfd402a4 ME |
149 | #else |
150 | #define __no_sanitize_thread | |
151 | #endif | |
152 | ||
5144f8a8 ME |
153 | #if __has_attribute(__no_sanitize_undefined__) |
154 | #define __no_sanitize_undefined __attribute__((no_sanitize_undefined)) | |
155 | #else | |
156 | #define __no_sanitize_undefined | |
157 | #endif | |
158 | ||
0aa5e49c | 159 | #if GCC_VERSION >= 50100 |
cafa0010 | 160 | #define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1 |
0aa5e49c KC |
161 | #endif |
162 | ||
8793bb7f AB |
163 | /* |
164 | * Turn individual warnings and errors on and off locally, depending | |
165 | * on version. | |
166 | */ | |
167 | #define __diag_GCC(version, severity, s) \ | |
168 | __diag_GCC_ ## version(__diag_GCC_ ## severity s) | |
169 | ||
170 | /* Severity used in pragma directives */ | |
171 | #define __diag_GCC_ignore ignored | |
172 | #define __diag_GCC_warn warning | |
173 | #define __diag_GCC_error error | |
174 | ||
8793bb7f AB |
175 | #define __diag_str1(s) #s |
176 | #define __diag_str(s) __diag_str1(s) | |
177 | #define __diag(s) _Pragma(__diag_str(GCC diagnostic s)) | |
8793bb7f AB |
178 | |
179 | #if GCC_VERSION >= 80000 | |
180 | #define __diag_GCC_8(s) __diag(s) | |
181 | #else | |
182 | #define __diag_GCC_8(s) | |
183 | #endif | |
3193c083 JP |
184 | |
185 | #define __no_fgcse __attribute__((optimize("-fno-gcse"))) |