1 /* SPDX-License-Identifier: GPL-2.0 */ !! 1 #ifndef __LINUX_COMPILER_H
2 #ifndef __LINUX_COMPILER_TYPES_H <<
3 #error "Please don't include <linux/compiler-g 2 #error "Please don't include <linux/compiler-gcc.h> directly, include <linux/compiler.h> instead."
4 #endif 3 #endif
5 4
6 /* 5 /*
7 * Common definitions for all gcc versions go 6 * Common definitions for all gcc versions go here.
8 */ 7 */
9 #define GCC_VERSION (__GNUC__ * 10000 8 #define GCC_VERSION (__GNUC__ * 10000 \
10 + __GNUC_MINOR__ * 100 9 + __GNUC_MINOR__ * 100 \
11 + __GNUC_PATCHLEVEL__) 10 + __GNUC_PATCHLEVEL__)
12 11
>> 12 /* Optimization barrier */
>> 13
>> 14 /* The "volatile" is due to gcc bugs */
>> 15 #define barrier() __asm__ __volatile__("": : :"memory")
>> 16 /*
>> 17 * This version is i.e. to prevent dead stores elimination on @ptr
>> 18 * where gcc and llvm may behave differently when otherwise using
>> 19 * normal barrier(): while gcc behavior gets along with a normal
>> 20 * barrier(), llvm needs an explicit input variable to be assumed
>> 21 * clobbered. The issue is as follows: while the inline asm might
>> 22 * access any memory it wants, the compiler could have fit all of
>> 23 * @ptr into memory registers instead, and since @ptr never escaped
>> 24 * from that, it proved that the inline asm wasn't touching any of
>> 25 * it. This version works well with both compilers, i.e. we're telling
>> 26 * the compiler that the inline asm absolutely may see the contents
>> 27 * of @ptr. See also: https://llvm.org/bugs/show_bug.cgi?id=15495
>> 28 */
>> 29 #define barrier_data(ptr) __asm__ __volatile__("": :"r"(ptr) :"memory")
>> 30
13 /* 31 /*
14 * This macro obfuscates arithmetic on a varia 32 * This macro obfuscates arithmetic on a variable address so that gcc
15 * shouldn't recognize the original var, and m 33 * shouldn't recognize the original var, and make assumptions about it.
16 * 34 *
17 * This is needed because the C standard makes 35 * This is needed because the C standard makes it undefined to do
18 * pointer arithmetic on "objects" outside the 36 * pointer arithmetic on "objects" outside their boundaries and the
19 * gcc optimizers assume this is the case. In 37 * gcc optimizers assume this is the case. In particular they
20 * assume such arithmetic does not wrap. 38 * assume such arithmetic does not wrap.
21 * 39 *
22 * A miscompilation has been observed because 40 * A miscompilation has been observed because of this on PPC.
23 * To work around it we hide the relationship 41 * To work around it we hide the relationship of the pointer and the object
24 * using this macro. 42 * using this macro.
25 * 43 *
26 * Versions of the ppc64 compiler before 4.1 h 44 * Versions of the ppc64 compiler before 4.1 had a bug where use of
27 * RELOC_HIDE could trash r30. The bug can be 45 * RELOC_HIDE could trash r30. The bug can be worked around by changing
28 * the inline assembly constraint from =g to = 46 * the inline assembly constraint from =g to =r, in this particular
29 * case either is valid. 47 * case either is valid.
30 */ 48 */
31 #define RELOC_HIDE(ptr, off) 49 #define RELOC_HIDE(ptr, off) \
32 ({ 50 ({ \
33 unsigned long __ptr; 51 unsigned long __ptr; \
34 __asm__ ("" : "=r"(__ptr) : ""(ptr)); 52 __asm__ ("" : "=r"(__ptr) : ""(ptr)); \
35 (typeof(ptr)) (__ptr + (off)); 53 (typeof(ptr)) (__ptr + (off)); \
36 }) 54 })
37 55
38 #ifdef CONFIG_MITIGATION_RETPOLINE !! 56 /* Make the optimizer believe the variable can be manipulated arbitrarily. */
39 #define __noretpoline __attribute__((__indirec !! 57 #define OPTIMIZER_HIDE_VAR(var) \
>> 58 __asm__ ("" : "=r" (var) : "" (var))
>> 59
>> 60 #ifdef __CHECKER__
>> 61 #define __must_be_array(a) 0
>> 62 #else
>> 63 /* &a[0] degrades to a pointer: a different type from an array */
>> 64 #define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
40 #endif 65 #endif
41 66
42 #if defined(LATENT_ENTROPY_PLUGIN) && !defined !! 67 /*
43 #define __latent_entropy __attribute__((latent !! 68 * Force always-inline if the user requests it so via the .config,
>> 69 * or if gcc is too old.
>> 70 * GCC does not warn about unused static inline functions for
>> 71 * -Wunused-function. This turns out to avoid the need for complex #ifdef
>> 72 * directives. Suppress the warning in clang as well by using "unused"
>> 73 * function attribute, which is redundant but not harmful for gcc.
>> 74 */
>> 75 #if !defined(CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING) || \
>> 76 !defined(CONFIG_OPTIMIZE_INLINING) || (__GNUC__ < 4)
>> 77 #define inline inline __attribute__((always_inline,unused)) notrace
>> 78 #define __inline__ __inline__ __attribute__((always_inline,unused)) notrace
>> 79 #define __inline __inline __attribute__((always_inline,unused)) notrace
>> 80 #else
>> 81 /* A lot of inline functions can cause havoc with function tracing */
>> 82 #define inline inline __attribute__((unused)) notrace
>> 83 #define __inline__ __inline__ __attribute__((unused)) notrace
>> 84 #define __inline __inline __attribute__((unused)) notrace
44 #endif 85 #endif
45 86
>> 87 #define __always_inline inline __attribute__((always_inline))
>> 88 #define noinline __attribute__((noinline))
>> 89
>> 90 #define __deprecated __attribute__((deprecated))
>> 91 #define __packed __attribute__((packed))
>> 92 #define __weak __attribute__((weak))
>> 93 #define __alias(symbol) __attribute__((alias(#symbol)))
>> 94
46 /* 95 /*
47 * calling noreturn functions, __builtin_unrea !! 96 * it doesn't make sense on ARM (currently the only user of __naked)
48 * confuse the stack allocation in gcc, leadin !! 97 * to trace naked functions because then mcount is called without
49 * frames, see https://gcc.gnu.org/bugzilla/sh !! 98 * stack and frame pointer being set up and there is no chance to
>> 99 * restore the lr register to the value before mcount was called.
50 * 100 *
51 * Adding an empty inline assembly before it w !! 101 * The asm() bodies of naked functions often depend on standard calling
>> 102 * conventions, therefore they must be noinline and noclone.
>> 103 *
>> 104 * GCC 4.[56] currently fail to enforce this, so we must do so ourselves.
>> 105 * See GCC PR44290.
52 */ 106 */
53 #define barrier_before_unreachable() asm volat !! 107 #define __naked __attribute__((naked)) noinline __noclone notrace
>> 108
>> 109 #define __noreturn __attribute__((noreturn))
54 110
55 /* 111 /*
56 * Mark a position in code as unreachable. Th !! 112 * From the GCC manual:
57 * suppress control flow warnings after asm bl !! 113 *
58 * control elsewhere. !! 114 * Many functions have no effects except the return value and their
>> 115 * return value depends only on the parameters and/or global
>> 116 * variables. Such a function can be subject to common subexpression
>> 117 * elimination and loop optimization just as an arithmetic operator
>> 118 * would be.
>> 119 * [...]
59 */ 120 */
60 #define unreachable() \ !! 121 #define __pure __attribute__((pure))
61 do { !! 122 #define __aligned(x) __attribute__((aligned(x)))
62 annotate_unreachable(); !! 123 #define __aligned_largest __attribute__((aligned))
63 barrier_before_unreachable(); !! 124 #define __printf(a, b) __attribute__((format(printf, a, b)))
64 __builtin_unreachable(); !! 125 #define __scanf(a, b) __attribute__((format(scanf, a, b)))
65 } while (0) !! 126 #define __attribute_const__ __attribute__((__const__))
>> 127 #define __maybe_unused __attribute__((unused))
>> 128 #define __always_unused __attribute__((unused))
>> 129 #define __mode(x) __attribute__((mode(x)))
66 130
67 #if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP) !! 131 /* gcc version specific checks */
68 #define __HAVE_BUILTIN_BSWAP32__ <<
69 #define __HAVE_BUILTIN_BSWAP64__ <<
70 #define __HAVE_BUILTIN_BSWAP16__ <<
71 #endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */ <<
72 132
73 #if GCC_VERSION >= 70000 !! 133 #if GCC_VERSION < 30200
74 #define KASAN_ABI_VERSION 5 !! 134 # error Sorry, your compiler is too old - please upgrade it.
75 #else <<
76 #define KASAN_ABI_VERSION 4 <<
77 #endif 135 #endif
78 136
79 #ifdef CONFIG_SHADOW_CALL_STACK !! 137 #if GCC_VERSION < 30300
80 #define __noscs __attribute__((__no_sanitize__ !! 138 # define __used __attribute__((__unused__))
>> 139 #else
>> 140 # define __used __attribute__((__used__))
81 #endif 141 #endif
82 142
83 #ifdef __SANITIZE_HWADDRESS__ !! 143 #ifdef CONFIG_GCOV_KERNEL
84 #define __no_sanitize_address __attribute__((_ !! 144 # if GCC_VERSION < 30400
85 #else !! 145 # error "GCOV profiling support for gcc versions below 3.4 not included"
86 #define __no_sanitize_address __attribute__((_ !! 146 # endif /* __GNUC_MINOR__ */
>> 147 #endif /* CONFIG_GCOV_KERNEL */
>> 148
>> 149 #if GCC_VERSION >= 30400
>> 150 #define __must_check __attribute__((warn_unused_result))
>> 151 #define __malloc __attribute__((__malloc__))
87 #endif 152 #endif
88 153
89 #if defined(__SANITIZE_THREAD__) !! 154 #if GCC_VERSION >= 40000
90 #define __no_sanitize_thread __attribute__((__ !! 155
91 #else !! 156 /* GCC 4.1.[01] miscompiles __weak */
92 #define __no_sanitize_thread !! 157 #ifdef __KERNEL__
>> 158 # if GCC_VERSION >= 40100 && GCC_VERSION <= 40101
>> 159 # error Your version of gcc miscompiles the __weak directive
>> 160 # endif
93 #endif 161 #endif
94 162
95 #define __no_sanitize_undefined __attribute__( !! 163 #define __used __attribute__((__used__))
>> 164 #define __compiler_offsetof(a, b) \
>> 165 __builtin_offsetof(a, b)
96 166
97 /* !! 167 #if GCC_VERSION >= 40100
98 * Only supported since gcc >= 12 !! 168 # define __compiletime_object_size(obj) __builtin_object_size(obj, 0)
>> 169 #endif
>> 170
>> 171 #if GCC_VERSION >= 40300
>> 172 /* Mark functions as cold. gcc will assume any path leading to a call
>> 173 * to them will be unlikely. This means a lot of manual unlikely()s
>> 174 * are unnecessary now for any paths leading to the usual suspects
>> 175 * like BUG(), printk(), panic() etc. [but let's keep them for now for
>> 176 * older compilers]
>> 177 *
>> 178 * Early snapshots of gcc 4.3 don't support this and we can't detect this
>> 179 * in the preprocessor, but we can live with this because they're unreleased.
>> 180 * Maketime probing would be overkill here.
>> 181 *
>> 182 * gcc also has a __attribute__((__hot__)) to move hot functions into
>> 183 * a special section, but I don't see any sense in this right now in
>> 184 * the kernel context
99 */ 185 */
100 #if defined(CONFIG_KCOV) && __has_attribute(__ !! 186 #define __cold __attribute__((__cold__))
101 #define __no_sanitize_coverage __attribute__(( !! 187
>> 188 #define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
>> 189
>> 190 #ifndef __CHECKER__
>> 191 # define __compiletime_warning(message) __attribute__((warning(message)))
>> 192 # define __compiletime_error(message) __attribute__((error(message)))
>> 193 #endif /* __CHECKER__ */
>> 194 #endif /* GCC_VERSION >= 40300 */
>> 195
>> 196 #if GCC_VERSION >= 40500
>> 197
>> 198 #ifndef __CHECKER__
>> 199 #ifdef LATENT_ENTROPY_PLUGIN
>> 200 #define __latent_entropy __attribute__((latent_entropy))
>> 201 #endif
>> 202 #endif
>> 203
>> 204 #ifdef CONFIG_STACK_VALIDATION
>> 205 #define annotate_unreachable() ({ \
>> 206 asm("%c0:\t\n" \
>> 207 ".pushsection .discard.unreachable\t\n" \
>> 208 ".long %c0b - .\t\n" \
>> 209 ".popsection\t\n" : : "i" (__LINE__)); \
>> 210 })
102 #else 211 #else
103 #define __no_sanitize_coverage !! 212 #define annotate_unreachable()
104 #endif 213 #endif
105 214
106 /* 215 /*
107 * Treat __SANITIZE_HWADDRESS__ the same as __ !! 216 * Mark a position in code as unreachable. This can be used to
108 * matching the defines used by Clang. !! 217 * suppress control flow warnings after asm blocks that transfer
>> 218 * control elsewhere.
>> 219 *
>> 220 * Early snapshots of gcc 4.5 don't support this and we can't detect
>> 221 * this in the preprocessor, but we can live with this because they're
>> 222 * unreleased. Really, we need to have autoconf for the kernel.
109 */ 223 */
110 #ifdef __SANITIZE_HWADDRESS__ !! 224 #define unreachable() \
111 #define __SANITIZE_ADDRESS__ !! 225 do { annotate_unreachable(); __builtin_unreachable(); } while (0)
>> 226
>> 227 /* Mark a function definition as prohibited from being cloned. */
>> 228 #define __noclone __attribute__((__noclone__, __optimize__("no-tracer")))
>> 229
>> 230 #ifdef RANDSTRUCT_PLUGIN
>> 231 #define __randomize_layout __attribute__((randomize_layout))
>> 232 #define __no_randomize_layout __attribute__((no_randomize_layout))
112 #endif 233 #endif
113 234
>> 235 #endif /* GCC_VERSION >= 40500 */
>> 236
>> 237 #if GCC_VERSION >= 40600
>> 238
114 /* 239 /*
115 * GCC does not support KMSAN. !! 240 * When used with Link Time Optimization, gcc can optimize away C functions or
>> 241 * variables which are referenced only from assembly code. __visible tells the
>> 242 * optimizer that something else uses this function or variable, thus preventing
>> 243 * this.
116 */ 244 */
117 #define __no_sanitize_memory !! 245 #define __visible __attribute__((externally_visible))
118 #define __no_kmsan_checks <<
119 246
120 /* 247 /*
121 * Turn individual warnings and errors on and !! 248 * RANDSTRUCT_PLUGIN wants to use an anonymous struct, but it is only
122 * on version. !! 249 * possible since GCC 4.6. To provide as much build testing coverage
>> 250 * as possible, this is used for all GCC 4.6+ builds, and not just on
>> 251 * RANDSTRUCT_PLUGIN builds.
123 */ 252 */
124 #define __diag_GCC(version, severity, s) \ !! 253 #define randomized_struct_fields_start struct {
125 __diag_GCC_ ## version(__diag_GCC_ ## !! 254 #define randomized_struct_fields_end } __randomize_layout;
126 255
127 /* Severity used in pragma directives */ !! 256 #endif /* GCC_VERSION >= 40600 */
128 #define __diag_GCC_ignore ignored <<
129 #define __diag_GCC_warn warning <<
130 #define __diag_GCC_error error <<
131 257
132 #define __diag_str1(s) #s <<
133 #define __diag_str(s) __diag_str1(s) <<
134 #define __diag(s) _Pragma(__diag <<
135 258
136 #if GCC_VERSION >= 80000 !! 259 #if GCC_VERSION >= 40900 && !defined(__CHECKER__)
137 #define __diag_GCC_8(s) __diag(s) !! 260 /*
138 #else !! 261 * __assume_aligned(n, k): Tell the optimizer that the returned
139 #define __diag_GCC_8(s) !! 262 * pointer can be assumed to be k modulo n. The second argument is
>> 263 * optional (default 0), so we use a variadic macro to make the
>> 264 * shorthand.
>> 265 *
>> 266 * Beware: Do not apply this to functions which may return
>> 267 * ERR_PTRs. Also, it is probably unwise to apply it to functions
>> 268 * returning extra information in the low bits (but in that case the
>> 269 * compiler should see some alignment anyway, when the return value is
>> 270 * massaged by 'flags = ptr & 3; ptr &= ~3;').
>> 271 */
>> 272 #define __assume_aligned(a, ...) __attribute__((__assume_aligned__(a, ## __VA_ARGS__)))
140 #endif 273 #endif
141 274
142 #define __diag_ignore_all(option, comment) \ !! 275 /*
143 __diag(__diag_GCC_ignore option) !! 276 * GCC 'asm goto' miscompiles certain code sequences:
>> 277 *
>> 278 * http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670
>> 279 *
>> 280 * Work it around via a compiler barrier quirk suggested by Jakub Jelinek.
>> 281 *
>> 282 * (asm goto is automatically volatile - the naming reflects this.)
>> 283 */
>> 284 #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
144 285
145 /* 286 /*
146 * Prior to 9.1, -Wno-alloc-size-larger-than ( !! 287 * sparse (__CHECKER__) pretends to be gcc, but can't do constant
147 * attribute) do not work, and must be disable !! 288 * folding in __builtin_bswap*() (yet), so don't set these for it.
148 */ 289 */
149 #if GCC_VERSION < 90100 !! 290 #if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP) && !defined(__CHECKER__)
150 #undef __alloc_size__ !! 291 #if GCC_VERSION >= 40400
>> 292 #define __HAVE_BUILTIN_BSWAP32__
>> 293 #define __HAVE_BUILTIN_BSWAP64__
>> 294 #endif
>> 295 #if GCC_VERSION >= 40800
>> 296 #define __HAVE_BUILTIN_BSWAP16__
151 #endif 297 #endif
>> 298 #endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP && !__CHECKER__ */
>> 299
>> 300 #if GCC_VERSION >= 70000
>> 301 #define KASAN_ABI_VERSION 5
>> 302 #elif GCC_VERSION >= 50000
>> 303 #define KASAN_ABI_VERSION 4
>> 304 #elif GCC_VERSION >= 40902
>> 305 #define KASAN_ABI_VERSION 3
>> 306 #endif
>> 307
>> 308 #if GCC_VERSION >= 40902
>> 309 /*
>> 310 * Tell the compiler that address safety instrumentation (KASAN)
>> 311 * should not be applied to that function.
>> 312 * Conflicts with inlining: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67368
>> 313 */
>> 314 #define __no_sanitize_address __attribute__((no_sanitize_address))
>> 315 #endif
>> 316
>> 317 #if GCC_VERSION >= 50100
>> 318 /*
>> 319 * Mark structures as requiring designated initializers.
>> 320 * https://gcc.gnu.org/onlinedocs/gcc/Designated-Inits.html
>> 321 */
>> 322 #define __designated_init __attribute__((designated_init))
>> 323 #endif
>> 324
>> 325 #endif /* gcc version >= 40000 specific checks */
>> 326
>> 327 #if !defined(__noclone)
>> 328 #define __noclone /* not needed */
>> 329 #endif
>> 330
>> 331 #if !defined(__no_sanitize_address)
>> 332 #define __no_sanitize_address
>> 333 #endif
>> 334
>> 335 /*
>> 336 * A trick to suppress uninitialized variable warning without generating any
>> 337 * code
>> 338 */
>> 339 #define uninitialized_var(x) x = x
152 340
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