1 /* SPDX-License-Identifier: GPL-2.0 */ 1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __LINUX_COMPILER_TYPES_H 2 #ifndef __LINUX_COMPILER_TYPES_H
3 #error "Please don't include <linux/compiler-g 3 #error "Please don't include <linux/compiler-gcc.h> directly, include <linux/compiler.h> instead."
4 #endif 4 #endif
5 5
6 /* 6 /*
7 * Common definitions for all gcc versions go 7 * Common definitions for all gcc versions go here.
8 */ 8 */
9 #define GCC_VERSION (__GNUC__ * 10000 9 #define GCC_VERSION (__GNUC__ * 10000 \
10 + __GNUC_MINOR__ * 100 10 + __GNUC_MINOR__ * 100 \
11 + __GNUC_PATCHLEVEL__) 11 + __GNUC_PATCHLEVEL__)
12 12
>> 13 /* Optimization barrier */
>> 14
>> 15 /* The "volatile" is due to gcc bugs */
>> 16 #define barrier() __asm__ __volatile__("": : :"memory")
>> 17 /*
>> 18 * This version is i.e. to prevent dead stores elimination on @ptr
>> 19 * where gcc and llvm may behave differently when otherwise using
>> 20 * normal barrier(): while gcc behavior gets along with a normal
>> 21 * barrier(), llvm needs an explicit input variable to be assumed
>> 22 * clobbered. The issue is as follows: while the inline asm might
>> 23 * access any memory it wants, the compiler could have fit all of
>> 24 * @ptr into memory registers instead, and since @ptr never escaped
>> 25 * from that, it proved that the inline asm wasn't touching any of
>> 26 * it. This version works well with both compilers, i.e. we're telling
>> 27 * the compiler that the inline asm absolutely may see the contents
>> 28 * of @ptr. See also: https://llvm.org/bugs/show_bug.cgi?id=15495
>> 29 */
>> 30 #define barrier_data(ptr) __asm__ __volatile__("": :"r"(ptr) :"memory")
>> 31
13 /* 32 /*
14 * This macro obfuscates arithmetic on a varia 33 * This macro obfuscates arithmetic on a variable address so that gcc
15 * shouldn't recognize the original var, and m 34 * shouldn't recognize the original var, and make assumptions about it.
16 * 35 *
17 * This is needed because the C standard makes 36 * This is needed because the C standard makes it undefined to do
18 * pointer arithmetic on "objects" outside the 37 * pointer arithmetic on "objects" outside their boundaries and the
19 * gcc optimizers assume this is the case. In 38 * gcc optimizers assume this is the case. In particular they
20 * assume such arithmetic does not wrap. 39 * assume such arithmetic does not wrap.
21 * 40 *
22 * A miscompilation has been observed because 41 * A miscompilation has been observed because of this on PPC.
23 * To work around it we hide the relationship 42 * To work around it we hide the relationship of the pointer and the object
24 * using this macro. 43 * using this macro.
25 * 44 *
26 * Versions of the ppc64 compiler before 4.1 h 45 * Versions of the ppc64 compiler before 4.1 had a bug where use of
27 * RELOC_HIDE could trash r30. The bug can be 46 * RELOC_HIDE could trash r30. The bug can be worked around by changing
28 * the inline assembly constraint from =g to = 47 * the inline assembly constraint from =g to =r, in this particular
29 * case either is valid. 48 * case either is valid.
30 */ 49 */
31 #define RELOC_HIDE(ptr, off) 50 #define RELOC_HIDE(ptr, off) \
32 ({ 51 ({ \
33 unsigned long __ptr; 52 unsigned long __ptr; \
34 __asm__ ("" : "=r"(__ptr) : ""(ptr)); 53 __asm__ ("" : "=r"(__ptr) : ""(ptr)); \
35 (typeof(ptr)) (__ptr + (off)); 54 (typeof(ptr)) (__ptr + (off)); \
36 }) 55 })
37 56
38 #ifdef CONFIG_MITIGATION_RETPOLINE !! 57 /* Make the optimizer believe the variable can be manipulated arbitrarily. */
39 #define __noretpoline __attribute__((__indirec !! 58 #define OPTIMIZER_HIDE_VAR(var) \
>> 59 __asm__ ("" : "=r" (var) : "" (var))
>> 60
>> 61 #ifdef __CHECKER__
>> 62 #define __must_be_array(a) 0
>> 63 #else
>> 64 /* &a[0] degrades to a pointer: a different type from an array */
>> 65 #define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
>> 66 #endif
>> 67
>> 68 /*
>> 69 * Force always-inline if the user requests it so via the .config,
>> 70 * or if gcc is too old.
>> 71 * GCC does not warn about unused static inline functions for
>> 72 * -Wunused-function. This turns out to avoid the need for complex #ifdef
>> 73 * directives. Suppress the warning in clang as well by using "unused"
>> 74 * function attribute, which is redundant but not harmful for gcc.
>> 75 */
>> 76 #if !defined(CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING) || \
>> 77 !defined(CONFIG_OPTIMIZE_INLINING) || (__GNUC__ < 4)
>> 78 #define inline inline __attribute__((always_inline,unused)) notrace
>> 79 #define __inline__ __inline__ __attribute__((always_inline,unused)) notrace
>> 80 #define __inline __inline __attribute__((always_inline,unused)) notrace
>> 81 #else
>> 82 /* A lot of inline functions can cause havoc with function tracing */
>> 83 #define inline inline __attribute__((unused)) notrace
>> 84 #define __inline__ __inline__ __attribute__((unused)) notrace
>> 85 #define __inline __inline __attribute__((unused)) notrace
>> 86 #endif
>> 87
>> 88 #define __always_inline inline __attribute__((always_inline))
>> 89 #define noinline __attribute__((noinline))
>> 90
>> 91 #define __deprecated __attribute__((deprecated))
>> 92 #define __packed __attribute__((packed))
>> 93 #define __weak __attribute__((weak))
>> 94 #define __alias(symbol) __attribute__((alias(#symbol)))
>> 95
>> 96 #ifdef RETPOLINE
>> 97 #define __noretpoline __attribute__((indirect_branch("keep")))
>> 98 #endif
>> 99
>> 100 /*
>> 101 * it doesn't make sense on ARM (currently the only user of __naked)
>> 102 * to trace naked functions because then mcount is called without
>> 103 * stack and frame pointer being set up and there is no chance to
>> 104 * restore the lr register to the value before mcount was called.
>> 105 *
>> 106 * The asm() bodies of naked functions often depend on standard calling
>> 107 * conventions, therefore they must be noinline and noclone.
>> 108 *
>> 109 * GCC 4.[56] currently fail to enforce this, so we must do so ourselves.
>> 110 * See GCC PR44290.
>> 111 */
>> 112 #define __naked __attribute__((naked)) noinline __noclone notrace
>> 113
>> 114 #define __noreturn __attribute__((noreturn))
>> 115
>> 116 /*
>> 117 * From the GCC manual:
>> 118 *
>> 119 * Many functions have no effects except the return value and their
>> 120 * return value depends only on the parameters and/or global
>> 121 * variables. Such a function can be subject to common subexpression
>> 122 * elimination and loop optimization just as an arithmetic operator
>> 123 * would be.
>> 124 * [...]
>> 125 */
>> 126 #define __pure __attribute__((pure))
>> 127 #define __aligned(x) __attribute__((aligned(x)))
>> 128 #define __aligned_largest __attribute__((aligned))
>> 129 #define __printf(a, b) __attribute__((format(printf, a, b)))
>> 130 #define __scanf(a, b) __attribute__((format(scanf, a, b)))
>> 131 #define __attribute_const__ __attribute__((__const__))
>> 132 #define __maybe_unused __attribute__((unused))
>> 133 #define __always_unused __attribute__((unused))
>> 134 #define __mode(x) __attribute__((mode(x)))
>> 135
>> 136 /* gcc version specific checks */
>> 137
>> 138 #if GCC_VERSION < 30200
>> 139 # error Sorry, your compiler is too old - please upgrade it.
>> 140 #endif
>> 141
>> 142 #if GCC_VERSION < 30300
>> 143 # define __used __attribute__((__unused__))
>> 144 #else
>> 145 # define __used __attribute__((__used__))
>> 146 #endif
>> 147
>> 148 #ifdef CONFIG_GCOV_KERNEL
>> 149 # if GCC_VERSION < 30400
>> 150 # error "GCOV profiling support for gcc versions below 3.4 not included"
>> 151 # endif /* __GNUC_MINOR__ */
>> 152 #endif /* CONFIG_GCOV_KERNEL */
>> 153
>> 154 #if GCC_VERSION >= 30400
>> 155 #define __must_check __attribute__((warn_unused_result))
>> 156 #define __malloc __attribute__((__malloc__))
40 #endif 157 #endif
41 158
42 #if defined(LATENT_ENTROPY_PLUGIN) && !defined !! 159 #if GCC_VERSION >= 40000
>> 160
>> 161 /* GCC 4.1.[01] miscompiles __weak */
>> 162 #ifdef __KERNEL__
>> 163 # if GCC_VERSION >= 40100 && GCC_VERSION <= 40101
>> 164 # error Your version of gcc miscompiles the __weak directive
>> 165 # endif
>> 166 #endif
>> 167
>> 168 #define __used __attribute__((__used__))
>> 169 #define __compiler_offsetof(a, b) \
>> 170 __builtin_offsetof(a, b)
>> 171
>> 172 #if GCC_VERSION >= 40100
>> 173 # define __compiletime_object_size(obj) __builtin_object_size(obj, 0)
>> 174 #endif
>> 175
>> 176 #if GCC_VERSION >= 40300
>> 177 /* Mark functions as cold. gcc will assume any path leading to a call
>> 178 * to them will be unlikely. This means a lot of manual unlikely()s
>> 179 * are unnecessary now for any paths leading to the usual suspects
>> 180 * like BUG(), printk(), panic() etc. [but let's keep them for now for
>> 181 * older compilers]
>> 182 *
>> 183 * Early snapshots of gcc 4.3 don't support this and we can't detect this
>> 184 * in the preprocessor, but we can live with this because they're unreleased.
>> 185 * Maketime probing would be overkill here.
>> 186 *
>> 187 * gcc also has a __attribute__((__hot__)) to move hot functions into
>> 188 * a special section, but I don't see any sense in this right now in
>> 189 * the kernel context
>> 190 */
>> 191 #define __cold __attribute__((__cold__))
>> 192
>> 193 #define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
>> 194
>> 195 #ifndef __CHECKER__
>> 196 # define __compiletime_warning(message) __attribute__((warning(message)))
>> 197 # define __compiletime_error(message) __attribute__((error(message)))
>> 198 #endif /* __CHECKER__ */
>> 199 #endif /* GCC_VERSION >= 40300 */
>> 200
>> 201 #if GCC_VERSION >= 40400
>> 202 #define __optimize(level) __attribute__((__optimize__(level)))
>> 203 #define __nostackprotector __optimize("no-stack-protector")
>> 204 #endif /* GCC_VERSION >= 40400 */
>> 205
>> 206 #if GCC_VERSION >= 40500
>> 207
>> 208 #ifndef __CHECKER__
>> 209 #ifdef LATENT_ENTROPY_PLUGIN
43 #define __latent_entropy __attribute__((latent 210 #define __latent_entropy __attribute__((latent_entropy))
44 #endif 211 #endif
>> 212 #endif
45 213
46 /* 214 /*
47 * calling noreturn functions, __builtin_unrea 215 * calling noreturn functions, __builtin_unreachable() and __builtin_trap()
48 * confuse the stack allocation in gcc, leadin 216 * confuse the stack allocation in gcc, leading to overly large stack
49 * frames, see https://gcc.gnu.org/bugzilla/sh 217 * frames, see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365
50 * 218 *
51 * Adding an empty inline assembly before it w 219 * Adding an empty inline assembly before it works around the problem
52 */ 220 */
53 #define barrier_before_unreachable() asm volat 221 #define barrier_before_unreachable() asm volatile("")
54 222
55 /* 223 /*
56 * Mark a position in code as unreachable. Th 224 * Mark a position in code as unreachable. This can be used to
57 * suppress control flow warnings after asm bl 225 * suppress control flow warnings after asm blocks that transfer
58 * control elsewhere. 226 * control elsewhere.
>> 227 *
>> 228 * Early snapshots of gcc 4.5 don't support this and we can't detect
>> 229 * this in the preprocessor, but we can live with this because they're
>> 230 * unreleased. Really, we need to have autoconf for the kernel.
59 */ 231 */
60 #define unreachable() \ 232 #define unreachable() \
61 do { 233 do { \
62 annotate_unreachable(); 234 annotate_unreachable(); \
63 barrier_before_unreachable(); 235 barrier_before_unreachable(); \
64 __builtin_unreachable(); 236 __builtin_unreachable(); \
65 } while (0) 237 } while (0)
66 238
67 #if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP) !! 239 /* Mark a function definition as prohibited from being cloned. */
68 #define __HAVE_BUILTIN_BSWAP32__ !! 240 #define __noclone __attribute__((__noclone__, __optimize__("no-tracer")))
69 #define __HAVE_BUILTIN_BSWAP64__ <<
70 #define __HAVE_BUILTIN_BSWAP16__ <<
71 #endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */ <<
72 241
73 #if GCC_VERSION >= 70000 !! 242 #if defined(RANDSTRUCT_PLUGIN) && !defined(__CHECKER__)
74 #define KASAN_ABI_VERSION 5 !! 243 #define __randomize_layout __attribute__((randomize_layout))
75 #else !! 244 #define __no_randomize_layout __attribute__((no_randomize_layout))
76 #define KASAN_ABI_VERSION 4 !! 245 /* This anon struct can add padding, so only enable it under randstruct. */
>> 246 #define randomized_struct_fields_start struct {
>> 247 #define randomized_struct_fields_end } __randomize_layout;
77 #endif 248 #endif
78 249
79 #ifdef CONFIG_SHADOW_CALL_STACK !! 250 #endif /* GCC_VERSION >= 40500 */
80 #define __noscs __attribute__((__no_sanitize__ <<
81 #endif <<
82 251
83 #ifdef __SANITIZE_HWADDRESS__ !! 252 #if GCC_VERSION >= 40600
84 #define __no_sanitize_address __attribute__((_ <<
85 #else <<
86 #define __no_sanitize_address __attribute__((_ <<
87 #endif <<
88 253
89 #if defined(__SANITIZE_THREAD__) !! 254 /*
90 #define __no_sanitize_thread __attribute__((__ !! 255 * When used with Link Time Optimization, gcc can optimize away C functions or
91 #else !! 256 * variables which are referenced only from assembly code. __visible tells the
92 #define __no_sanitize_thread !! 257 * optimizer that something else uses this function or variable, thus preventing
93 #endif !! 258 * this.
>> 259 */
>> 260 #define __visible __attribute__((externally_visible))
>> 261
>> 262 #endif /* GCC_VERSION >= 40600 */
94 263
95 #define __no_sanitize_undefined __attribute__( <<
96 264
>> 265 #if GCC_VERSION >= 40900 && !defined(__CHECKER__)
97 /* 266 /*
98 * Only supported since gcc >= 12 !! 267 * __assume_aligned(n, k): Tell the optimizer that the returned
>> 268 * pointer can be assumed to be k modulo n. The second argument is
>> 269 * optional (default 0), so we use a variadic macro to make the
>> 270 * shorthand.
>> 271 *
>> 272 * Beware: Do not apply this to functions which may return
>> 273 * ERR_PTRs. Also, it is probably unwise to apply it to functions
>> 274 * returning extra information in the low bits (but in that case the
>> 275 * compiler should see some alignment anyway, when the return value is
>> 276 * massaged by 'flags = ptr & 3; ptr &= ~3;').
99 */ 277 */
100 #if defined(CONFIG_KCOV) && __has_attribute(__ !! 278 #define __assume_aligned(a, ...) __attribute__((__assume_aligned__(a, ## __VA_ARGS__)))
101 #define __no_sanitize_coverage __attribute__(( <<
102 #else <<
103 #define __no_sanitize_coverage <<
104 #endif 279 #endif
105 280
106 /* 281 /*
107 * Treat __SANITIZE_HWADDRESS__ the same as __ !! 282 * GCC 'asm goto' miscompiles certain code sequences:
108 * matching the defines used by Clang. !! 283 *
>> 284 * http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670
>> 285 *
>> 286 * Work it around via a compiler barrier quirk suggested by Jakub Jelinek.
>> 287 *
>> 288 * (asm goto is automatically volatile - the naming reflects this.)
109 */ 289 */
110 #ifdef __SANITIZE_HWADDRESS__ !! 290 #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
111 #define __SANITIZE_ADDRESS__ <<
112 #endif <<
113 291
114 /* 292 /*
115 * GCC does not support KMSAN. !! 293 * sparse (__CHECKER__) pretends to be gcc, but can't do constant
>> 294 * folding in __builtin_bswap*() (yet), so don't set these for it.
116 */ 295 */
117 #define __no_sanitize_memory !! 296 #if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP) && !defined(__CHECKER__)
118 #define __no_kmsan_checks !! 297 #if GCC_VERSION >= 40400
>> 298 #define __HAVE_BUILTIN_BSWAP32__
>> 299 #define __HAVE_BUILTIN_BSWAP64__
>> 300 #endif
>> 301 #if GCC_VERSION >= 40800
>> 302 #define __HAVE_BUILTIN_BSWAP16__
>> 303 #endif
>> 304 #endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP && !__CHECKER__ */
119 305
>> 306 #if GCC_VERSION >= 70000
>> 307 #define KASAN_ABI_VERSION 5
>> 308 #elif GCC_VERSION >= 50000
>> 309 #define KASAN_ABI_VERSION 4
>> 310 #elif GCC_VERSION >= 40902
>> 311 #define KASAN_ABI_VERSION 3
>> 312 #endif
>> 313
>> 314 #if GCC_VERSION >= 40902
120 /* 315 /*
121 * Turn individual warnings and errors on and !! 316 * Tell the compiler that address safety instrumentation (KASAN)
122 * on version. !! 317 * should not be applied to that function.
>> 318 * Conflicts with inlining: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67368
123 */ 319 */
124 #define __diag_GCC(version, severity, s) \ !! 320 #define __no_sanitize_address __attribute__((no_sanitize_address))
125 __diag_GCC_ ## version(__diag_GCC_ ## !! 321 #endif
126 322
127 /* Severity used in pragma directives */ !! 323 #if GCC_VERSION >= 50100
128 #define __diag_GCC_ignore ignored !! 324 /*
129 #define __diag_GCC_warn warning !! 325 * Mark structures as requiring designated initializers.
130 #define __diag_GCC_error error !! 326 * https://gcc.gnu.org/onlinedocs/gcc/Designated-Inits.html
>> 327 */
>> 328 #define __designated_init __attribute__((designated_init))
>> 329 #endif
131 330
132 #define __diag_str1(s) #s !! 331 #endif /* gcc version >= 40000 specific checks */
133 #define __diag_str(s) __diag_str1(s) <<
134 #define __diag(s) _Pragma(__diag <<
135 332
136 #if GCC_VERSION >= 80000 !! 333 #if !defined(__noclone)
137 #define __diag_GCC_8(s) __diag(s) !! 334 #define __noclone /* not needed */
138 #else <<
139 #define __diag_GCC_8(s) <<
140 #endif 335 #endif
141 336
142 #define __diag_ignore_all(option, comment) \ !! 337 #if !defined(__no_sanitize_address)
143 __diag(__diag_GCC_ignore option) !! 338 #define __no_sanitize_address
>> 339 #endif
144 340
145 /* 341 /*
146 * Prior to 9.1, -Wno-alloc-size-larger-than ( !! 342 * A trick to suppress uninitialized variable warning without generating any
147 * attribute) do not work, and must be disable !! 343 * code
148 */ 344 */
149 #if GCC_VERSION < 90100 !! 345 #define uninitialized_var(x) x = x
150 #undef __alloc_size__ <<
151 #endif <<
152 346
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