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 */
>> 71 #if !defined(CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING) || \
>> 72 !defined(CONFIG_OPTIMIZE_INLINING) || (__GNUC__ < 4)
>> 73 #define inline inline __attribute__((always_inline)) notrace
>> 74 #define __inline__ __inline__ __attribute__((always_inline)) notrace
>> 75 #define __inline __inline __attribute__((always_inline)) notrace
>> 76 #else
>> 77 /* A lot of inline functions can cause havoc with function tracing */
>> 78 #define inline inline notrace
>> 79 #define __inline__ __inline__ notrace
>> 80 #define __inline __inline notrace
44 #endif 81 #endif
45 82
>> 83 #define __always_inline inline __attribute__((always_inline))
>> 84 #define noinline __attribute__((noinline))
>> 85
>> 86 #define __deprecated __attribute__((deprecated))
>> 87 #define __packed __attribute__((packed))
>> 88 #define __weak __attribute__((weak))
>> 89 #define __alias(symbol) __attribute__((alias(#symbol)))
>> 90
46 /* 91 /*
47 * calling noreturn functions, __builtin_unrea !! 92 * it doesn't make sense on ARM (currently the only user of __naked)
48 * confuse the stack allocation in gcc, leadin !! 93 * to trace naked functions because then mcount is called without
49 * frames, see https://gcc.gnu.org/bugzilla/sh !! 94 * stack and frame pointer being set up and there is no chance to
>> 95 * restore the lr register to the value before mcount was called.
>> 96 *
>> 97 * The asm() bodies of naked functions often depend on standard calling
>> 98 * conventions, therefore they must be noinline and noclone.
50 * 99 *
51 * Adding an empty inline assembly before it w !! 100 * GCC 4.[56] currently fail to enforce this, so we must do so ourselves.
>> 101 * See GCC PR44290.
52 */ 102 */
53 #define barrier_before_unreachable() asm volat !! 103 #define __naked __attribute__((naked)) noinline __noclone notrace
>> 104
>> 105 #define __noreturn __attribute__((noreturn))
54 106
55 /* 107 /*
56 * Mark a position in code as unreachable. Th !! 108 * From the GCC manual:
57 * suppress control flow warnings after asm bl !! 109 *
58 * control elsewhere. !! 110 * Many functions have no effects except the return value and their
>> 111 * return value depends only on the parameters and/or global
>> 112 * variables. Such a function can be subject to common subexpression
>> 113 * elimination and loop optimization just as an arithmetic operator
>> 114 * would be.
>> 115 * [...]
59 */ 116 */
60 #define unreachable() \ !! 117 #define __pure __attribute__((pure))
61 do { !! 118 #define __aligned(x) __attribute__((aligned(x)))
62 annotate_unreachable(); !! 119 #define __aligned_largest __attribute__((aligned))
63 barrier_before_unreachable(); !! 120 #define __printf(a, b) __attribute__((format(printf, a, b)))
64 __builtin_unreachable(); !! 121 #define __scanf(a, b) __attribute__((format(scanf, a, b)))
65 } while (0) !! 122 #define __attribute_const__ __attribute__((__const__))
>> 123 #define __maybe_unused __attribute__((unused))
>> 124 #define __always_unused __attribute__((unused))
>> 125 #define __mode(x) __attribute__((mode(x)))
66 126
67 #if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP) !! 127 /* 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 */ <<
72 128
73 #if GCC_VERSION >= 70000 !! 129 #if GCC_VERSION < 30200
74 #define KASAN_ABI_VERSION 5 !! 130 # error Sorry, your compiler is too old - please upgrade it.
>> 131 #endif
>> 132
>> 133 #if GCC_VERSION < 30300
>> 134 # define __used __attribute__((__unused__))
75 #else 135 #else
76 #define KASAN_ABI_VERSION 4 !! 136 # define __used __attribute__((__used__))
77 #endif 137 #endif
78 138
79 #ifdef CONFIG_SHADOW_CALL_STACK !! 139 #ifdef CONFIG_GCOV_KERNEL
80 #define __noscs __attribute__((__no_sanitize__ !! 140 # if GCC_VERSION < 30400
>> 141 # error "GCOV profiling support for gcc versions below 3.4 not included"
>> 142 # endif /* __GNUC_MINOR__ */
>> 143 #endif /* CONFIG_GCOV_KERNEL */
>> 144
>> 145 #if GCC_VERSION >= 30400
>> 146 #define __must_check __attribute__((warn_unused_result))
>> 147 #define __malloc __attribute__((__malloc__))
81 #endif 148 #endif
82 149
83 #ifdef __SANITIZE_HWADDRESS__ !! 150 #if GCC_VERSION >= 40000
84 #define __no_sanitize_address __attribute__((_ !! 151
85 #else !! 152 /* GCC 4.1.[01] miscompiles __weak */
86 #define __no_sanitize_address __attribute__((_ !! 153 #ifdef __KERNEL__
>> 154 # if GCC_VERSION >= 40100 && GCC_VERSION <= 40101
>> 155 # error Your version of gcc miscompiles the __weak directive
>> 156 # endif
87 #endif 157 #endif
88 158
89 #if defined(__SANITIZE_THREAD__) !! 159 #define __used __attribute__((__used__))
90 #define __no_sanitize_thread __attribute__((__ !! 160 #define __compiler_offsetof(a, b) \
>> 161 __builtin_offsetof(a, b)
>> 162
>> 163 #if GCC_VERSION >= 40100
>> 164 # define __compiletime_object_size(obj) __builtin_object_size(obj, 0)
>> 165 #endif
>> 166
>> 167 #if GCC_VERSION >= 40300
>> 168 /* Mark functions as cold. gcc will assume any path leading to a call
>> 169 * to them will be unlikely. This means a lot of manual unlikely()s
>> 170 * are unnecessary now for any paths leading to the usual suspects
>> 171 * like BUG(), printk(), panic() etc. [but let's keep them for now for
>> 172 * older compilers]
>> 173 *
>> 174 * Early snapshots of gcc 4.3 don't support this and we can't detect this
>> 175 * in the preprocessor, but we can live with this because they're unreleased.
>> 176 * Maketime probing would be overkill here.
>> 177 *
>> 178 * gcc also has a __attribute__((__hot__)) to move hot functions into
>> 179 * a special section, but I don't see any sense in this right now in
>> 180 * the kernel context
>> 181 */
>> 182 #define __cold __attribute__((__cold__))
>> 183
>> 184 #define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
>> 185
>> 186 #ifndef __CHECKER__
>> 187 # define __compiletime_warning(message) __attribute__((warning(message)))
>> 188 # define __compiletime_error(message) __attribute__((error(message)))
>> 189 #endif /* __CHECKER__ */
>> 190 #endif /* GCC_VERSION >= 40300 */
>> 191
>> 192 #if GCC_VERSION >= 40500
>> 193
>> 194 #ifndef __CHECKER__
>> 195 #ifdef LATENT_ENTROPY_PLUGIN
>> 196 #define __latent_entropy __attribute__((latent_entropy))
>> 197 #endif
>> 198 #endif
>> 199
>> 200 #ifdef CONFIG_STACK_VALIDATION
>> 201 #define annotate_unreachable() ({ \
>> 202 asm("%c0:\t\n" \
>> 203 ".pushsection .discard.unreachable\t\n" \
>> 204 ".long %c0b - .\t\n" \
>> 205 ".popsection\t\n" : : "i" (__LINE__)); \
>> 206 })
91 #else 207 #else
92 #define __no_sanitize_thread !! 208 #define annotate_unreachable()
93 #endif 209 #endif
94 210
95 #define __no_sanitize_undefined __attribute__( !! 211 /*
>> 212 * Mark a position in code as unreachable. This can be used to
>> 213 * suppress control flow warnings after asm blocks that transfer
>> 214 * control elsewhere.
>> 215 *
>> 216 * Early snapshots of gcc 4.5 don't support this and we can't detect
>> 217 * this in the preprocessor, but we can live with this because they're
>> 218 * unreleased. Really, we need to have autoconf for the kernel.
>> 219 */
>> 220 #define unreachable() \
>> 221 do { annotate_unreachable(); __builtin_unreachable(); } while (0)
>> 222
>> 223 /* Mark a function definition as prohibited from being cloned. */
>> 224 #define __noclone __attribute__((__noclone__, __optimize__("no-tracer")))
>> 225
>> 226 #endif /* GCC_VERSION >= 40500 */
96 227
>> 228 #if GCC_VERSION >= 40600
97 /* 229 /*
98 * Only supported since gcc >= 12 !! 230 * When used with Link Time Optimization, gcc can optimize away C functions or
>> 231 * variables which are referenced only from assembly code. __visible tells the
>> 232 * optimizer that something else uses this function or variable, thus preventing
>> 233 * this.
99 */ 234 */
100 #if defined(CONFIG_KCOV) && __has_attribute(__ !! 235 #define __visible __attribute__((externally_visible))
101 #define __no_sanitize_coverage __attribute__(( <<
102 #else <<
103 #define __no_sanitize_coverage <<
104 #endif 236 #endif
105 237
>> 238
>> 239 #if GCC_VERSION >= 40900 && !defined(__CHECKER__)
106 /* 240 /*
107 * Treat __SANITIZE_HWADDRESS__ the same as __ !! 241 * __assume_aligned(n, k): Tell the optimizer that the returned
108 * matching the defines used by Clang. !! 242 * pointer can be assumed to be k modulo n. The second argument is
>> 243 * optional (default 0), so we use a variadic macro to make the
>> 244 * shorthand.
>> 245 *
>> 246 * Beware: Do not apply this to functions which may return
>> 247 * ERR_PTRs. Also, it is probably unwise to apply it to functions
>> 248 * returning extra information in the low bits (but in that case the
>> 249 * compiler should see some alignment anyway, when the return value is
>> 250 * massaged by 'flags = ptr & 3; ptr &= ~3;').
109 */ 251 */
110 #ifdef __SANITIZE_HWADDRESS__ !! 252 #define __assume_aligned(a, ...) __attribute__((__assume_aligned__(a, ## __VA_ARGS__)))
111 #define __SANITIZE_ADDRESS__ <<
112 #endif 253 #endif
113 254
114 /* 255 /*
115 * GCC does not support KMSAN. !! 256 * GCC 'asm goto' miscompiles certain code sequences:
>> 257 *
>> 258 * http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670
>> 259 *
>> 260 * Work it around via a compiler barrier quirk suggested by Jakub Jelinek.
>> 261 *
>> 262 * (asm goto is automatically volatile - the naming reflects this.)
116 */ 263 */
117 #define __no_sanitize_memory !! 264 #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
118 #define __no_kmsan_checks <<
119 265
120 /* 266 /*
121 * Turn individual warnings and errors on and !! 267 * sparse (__CHECKER__) pretends to be gcc, but can't do constant
122 * on version. !! 268 * folding in __builtin_bswap*() (yet), so don't set these for it.
123 */ 269 */
124 #define __diag_GCC(version, severity, s) \ !! 270 #if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP) && !defined(__CHECKER__)
125 __diag_GCC_ ## version(__diag_GCC_ ## !! 271 #if GCC_VERSION >= 40400
>> 272 #define __HAVE_BUILTIN_BSWAP32__
>> 273 #define __HAVE_BUILTIN_BSWAP64__
>> 274 #endif
>> 275 #if GCC_VERSION >= 40800
>> 276 #define __HAVE_BUILTIN_BSWAP16__
>> 277 #endif
>> 278 #endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP && !__CHECKER__ */
>> 279
>> 280 #if GCC_VERSION >= 70000
>> 281 #define KASAN_ABI_VERSION 5
>> 282 #elif GCC_VERSION >= 50000
>> 283 #define KASAN_ABI_VERSION 4
>> 284 #elif GCC_VERSION >= 40902
>> 285 #define KASAN_ABI_VERSION 3
>> 286 #endif
126 287
127 /* Severity used in pragma directives */ !! 288 #if GCC_VERSION >= 40902
128 #define __diag_GCC_ignore ignored !! 289 /*
129 #define __diag_GCC_warn warning !! 290 * Tell the compiler that address safety instrumentation (KASAN)
130 #define __diag_GCC_error error !! 291 * should not be applied to that function.
>> 292 * Conflicts with inlining: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67368
>> 293 */
>> 294 #define __no_sanitize_address __attribute__((no_sanitize_address))
>> 295 #endif
131 296
132 #define __diag_str1(s) #s !! 297 #endif /* gcc version >= 40000 specific checks */
133 #define __diag_str(s) __diag_str1(s) <<
134 #define __diag(s) _Pragma(__diag <<
135 298
136 #if GCC_VERSION >= 80000 !! 299 #if !defined(__noclone)
137 #define __diag_GCC_8(s) __diag(s) !! 300 #define __noclone /* not needed */
138 #else <<
139 #define __diag_GCC_8(s) <<
140 #endif 301 #endif
141 302
142 #define __diag_ignore_all(option, comment) \ !! 303 #if !defined(__no_sanitize_address)
143 __diag(__diag_GCC_ignore option) !! 304 #define __no_sanitize_address
>> 305 #endif
144 306
145 /* 307 /*
146 * Prior to 9.1, -Wno-alloc-size-larger-than ( !! 308 * A trick to suppress uninitialized variable warning without generating any
147 * attribute) do not work, and must be disable !! 309 * code
148 */ 310 */
149 #if GCC_VERSION < 90100 !! 311 #define uninitialized_var(x) x = x
150 #undef __alloc_size__ <<
151 #endif <<
152 312
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