1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __LINUX_COMPILER_TYPES_H
3 #define __LINUX_COMPILER_TYPES_H
4
5 #ifndef __ASSEMBLY__
6
7 /*
8 * Skipped when running bindgen due to a libclang issue;
9 * see https://github.com/rust-lang/rust-bindgen/issues/2244.
10 */
11 #if defined(CONFIG_DEBUG_INFO_BTF) && defined(CONFIG_PAHOLE_HAS_BTF_TAG) && \
12 __has_attribute(btf_type_tag) && !defined(__BINDGEN__)
13 # define BTF_TYPE_TAG(value) __attribute__((btf_type_tag(#value)))
14 #else
15 # define BTF_TYPE_TAG(value) /* nothing */
16 #endif
17
18 /* sparse defines __CHECKER__; see Documentation/dev-tools/sparse.rst */
19 #ifdef __CHECKER__
20 /* address spaces */
21 # define __kernel __attribute__((address_space(0)))
22 # define __user __attribute__((noderef, address_space(__user)))
23 # define __iomem __attribute__((noderef, address_space(__iomem)))
24 # define __percpu __attribute__((noderef, address_space(__percpu)))
25 # define __rcu __attribute__((noderef, address_space(__rcu)))
__chk_user_ptr(const volatile void __user * ptr)26 static inline void __chk_user_ptr(const volatile void __user *ptr) { }
__chk_io_ptr(const volatile void __iomem * ptr)27 static inline void __chk_io_ptr(const volatile void __iomem *ptr) { }
28 /* context/locking */
29 # define __must_hold(x) __attribute__((context(x,1,1)))
30 # define __acquires(x) __attribute__((context(x,0,1)))
31 # define __cond_acquires(x) __attribute__((context(x,0,-1)))
32 # define __releases(x) __attribute__((context(x,1,0)))
33 # define __acquire(x) __context__(x,1)
34 # define __release(x) __context__(x,-1)
35 # define __cond_lock(x,c) ((c) ? ({ __acquire(x); 1; }) : 0)
36 /* other */
37 # define __force __attribute__((force))
38 # define __nocast __attribute__((nocast))
39 # define __safe __attribute__((safe))
40 # define __private __attribute__((noderef))
41 # define ACCESS_PRIVATE(p, member) (*((typeof((p)->member) __force *) &(p)->member))
42 #else /* __CHECKER__ */
43 /* address spaces */
44 # define __kernel
45 # ifdef STRUCTLEAK_PLUGIN
46 # define __user __attribute__((user))
47 # else
48 # define __user BTF_TYPE_TAG(user)
49 # endif
50 # define __iomem
51 # define __percpu BTF_TYPE_TAG(percpu)
52 # define __rcu BTF_TYPE_TAG(rcu)
53
54 # define __chk_user_ptr(x) (void)0
55 # define __chk_io_ptr(x) (void)0
56 /* context/locking */
57 # define __must_hold(x)
58 # define __acquires(x)
59 # define __cond_acquires(x)
60 # define __releases(x)
61 # define __acquire(x) (void)0
62 # define __release(x) (void)0
63 # define __cond_lock(x,c) (c)
64 /* other */
65 # define __force
66 # define __nocast
67 # define __safe
68 # define __private
69 # define ACCESS_PRIVATE(p, member) ((p)->member)
70 # define __builtin_warning(x, y...) (1)
71 #endif /* __CHECKER__ */
72
73 /* Indirect macros required for expanded argument pasting, eg. __LINE__. */
74 #define ___PASTE(a,b) a##b
75 #define __PASTE(a,b) ___PASTE(a,b)
76
77 #ifdef __KERNEL__
78
79 /* Attributes */
80 #include <linux/compiler_attributes.h>
81
82 #if CONFIG_FUNCTION_ALIGNMENT > 0
83 #define __function_aligned __aligned(CONFIG_FUNCTION_ALIGNMENT)
84 #else
85 #define __function_aligned
86 #endif
87
88 /*
89 * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-cold-function-attribute
90 * gcc: https://gcc.gnu.org/onlinedocs/gcc/Label-Attributes.html#index-cold-label-attribute
91 *
92 * When -falign-functions=N is in use, we must avoid the cold attribute as
93 * contemporary versions of GCC drop the alignment for cold functions. Worse,
94 * GCC can implicitly mark callees of cold functions as cold themselves, so
95 * it's not sufficient to add __function_aligned here as that will not ensure
96 * that callees are correctly aligned.
97 *
98 * See:
99 *
100 * https://lore.kernel.org/lkml/Y77%2FqVgvaJidFpYt@FVFF77S0Q05N
101 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88345#c9
102 */
103 #if !defined(CONFIG_CC_IS_GCC) || (CONFIG_FUNCTION_ALIGNMENT == 0)
104 #define __cold __attribute__((__cold__))
105 #else
106 #define __cold
107 #endif
108
109 /*
110 * On x86-64 and arm64 targets, __preserve_most changes the calling convention
111 * of a function to make the code in the caller as unintrusive as possible. This
112 * convention behaves identically to the C calling convention on how arguments
113 * and return values are passed, but uses a different set of caller- and callee-
114 * saved registers.
115 *
116 * The purpose is to alleviates the burden of saving and recovering a large
117 * register set before and after the call in the caller. This is beneficial for
118 * rarely taken slow paths, such as error-reporting functions that may be called
119 * from hot paths.
120 *
121 * Note: This may conflict with instrumentation inserted on function entry which
122 * does not use __preserve_most or equivalent convention (if in assembly). Since
123 * function tracing assumes the normal C calling convention, where the attribute
124 * is supported, __preserve_most implies notrace. It is recommended to restrict
125 * use of the attribute to functions that should or already disable tracing.
126 *
127 * Optional: not supported by gcc.
128 *
129 * clang: https://clang.llvm.org/docs/AttributeReference.html#preserve-most
130 */
131 #if __has_attribute(__preserve_most__) && (defined(CONFIG_X86_64) || defined(CONFIG_ARM64))
132 # define __preserve_most notrace __attribute__((__preserve_most__))
133 #else
134 # define __preserve_most
135 #endif
136
137 /* Builtins */
138
139 /*
140 * __has_builtin is supported on gcc >= 10, clang >= 3 and icc >= 21.
141 * In the meantime, to support gcc < 10, we implement __has_builtin
142 * by hand.
143 */
144 #ifndef __has_builtin
145 #define __has_builtin(x) (0)
146 #endif
147
148 /* Compiler specific macros. */
149 #ifdef __clang__
150 #include <linux/compiler-clang.h>
151 #elif defined(__GNUC__)
152 /* The above compilers also define __GNUC__, so order is important here. */
153 #include <linux/compiler-gcc.h>
154 #else
155 #error "Unknown compiler"
156 #endif
157
158 /*
159 * Some architectures need to provide custom definitions of macros provided
160 * by linux/compiler-*.h, and can do so using asm/compiler.h. We include that
161 * conditionally rather than using an asm-generic wrapper in order to avoid
162 * build failures if any C compilation, which will include this file via an
163 * -include argument in c_flags, occurs prior to the asm-generic wrappers being
164 * generated.
165 */
166 #ifdef CONFIG_HAVE_ARCH_COMPILER_H
167 #include <asm/compiler.h>
168 #endif
169
170 struct ftrace_branch_data {
171 const char *func;
172 const char *file;
173 unsigned line;
174 union {
175 struct {
176 unsigned long correct;
177 unsigned long incorrect;
178 };
179 struct {
180 unsigned long miss;
181 unsigned long hit;
182 };
183 unsigned long miss_hit[2];
184 };
185 };
186
187 struct ftrace_likely_data {
188 struct ftrace_branch_data data;
189 unsigned long constant;
190 };
191
192 #if defined(CC_USING_HOTPATCH)
193 #define notrace __attribute__((hotpatch(0, 0)))
194 #elif defined(CC_USING_PATCHABLE_FUNCTION_ENTRY)
195 #define notrace __attribute__((patchable_function_entry(0, 0)))
196 #else
197 #define notrace __attribute__((__no_instrument_function__))
198 #endif
199
200 /*
201 * it doesn't make sense on ARM (currently the only user of __naked)
202 * to trace naked functions because then mcount is called without
203 * stack and frame pointer being set up and there is no chance to
204 * restore the lr register to the value before mcount was called.
205 */
206 #define __naked __attribute__((__naked__)) notrace
207
208 /*
209 * Prefer gnu_inline, so that extern inline functions do not emit an
210 * externally visible function. This makes extern inline behave as per gnu89
211 * semantics rather than c99. This prevents multiple symbol definition errors
212 * of extern inline functions at link time.
213 * A lot of inline functions can cause havoc with function tracing.
214 */
215 #define inline inline __gnu_inline __inline_maybe_unused notrace
216
217 /*
218 * gcc provides both __inline__ and __inline as alternate spellings of
219 * the inline keyword, though the latter is undocumented. New kernel
220 * code should only use the inline spelling, but some existing code
221 * uses __inline__. Since we #define inline above, to ensure
222 * __inline__ has the same semantics, we need this #define.
223 *
224 * However, the spelling __inline is strictly reserved for referring
225 * to the bare keyword.
226 */
227 #define __inline__ inline
228
229 /*
230 * GCC does not warn about unused static inline functions for -Wunused-function.
231 * Suppress the warning in clang as well by using __maybe_unused, but enable it
232 * for W=1 build. This will allow clang to find unused functions. Remove the
233 * __inline_maybe_unused entirely after fixing most of -Wunused-function warnings.
234 */
235 #ifdef KBUILD_EXTRA_WARN1
236 #define __inline_maybe_unused
237 #else
238 #define __inline_maybe_unused __maybe_unused
239 #endif
240
241 /*
242 * Rather then using noinline to prevent stack consumption, use
243 * noinline_for_stack instead. For documentation reasons.
244 */
245 #define noinline_for_stack noinline
246
247 /*
248 * Sanitizer helper attributes: Because using __always_inline and
249 * __no_sanitize_* conflict, provide helper attributes that will either expand
250 * to __no_sanitize_* in compilation units where instrumentation is enabled
251 * (__SANITIZE_*__), or __always_inline in compilation units without
252 * instrumentation (__SANITIZE_*__ undefined).
253 */
254 #ifdef __SANITIZE_ADDRESS__
255 /*
256 * We can't declare function 'inline' because __no_sanitize_address conflicts
257 * with inlining. Attempt to inline it may cause a build failure.
258 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67368
259 * '__maybe_unused' allows us to avoid defined-but-not-used warnings.
260 */
261 # define __no_kasan_or_inline __no_sanitize_address notrace __maybe_unused
262 # define __no_sanitize_or_inline __no_kasan_or_inline
263 #else
264 # define __no_kasan_or_inline __always_inline
265 #endif
266
267 #ifdef __SANITIZE_THREAD__
268 /*
269 * Clang still emits instrumentation for __tsan_func_{entry,exit}() and builtin
270 * atomics even with __no_sanitize_thread (to avoid false positives in userspace
271 * ThreadSanitizer). The kernel's requirements are stricter and we really do not
272 * want any instrumentation with __no_kcsan.
273 *
274 * Therefore we add __disable_sanitizer_instrumentation where available to
275 * disable all instrumentation. See Kconfig.kcsan where this is mandatory.
276 */
277 # define __no_kcsan __no_sanitize_thread __disable_sanitizer_instrumentation
278 # define __no_sanitize_or_inline __no_kcsan notrace __maybe_unused
279 #else
280 # define __no_kcsan
281 #endif
282
283 #ifdef __SANITIZE_MEMORY__
284 /*
285 * Similarly to KASAN and KCSAN, KMSAN loses function attributes of inlined
286 * functions, therefore disabling KMSAN checks also requires disabling inlining.
287 *
288 * __no_sanitize_or_inline effectively prevents KMSAN from reporting errors
289 * within the function and marks all its outputs as initialized.
290 */
291 # define __no_sanitize_or_inline __no_kmsan_checks notrace __maybe_unused
292 #endif
293
294 #ifndef __no_sanitize_or_inline
295 #define __no_sanitize_or_inline __always_inline
296 #endif
297
298 /*
299 * Optional: only supported since gcc >= 15
300 * Optional: only supported since clang >= 18
301 *
302 * gcc: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108896
303 * clang: https://github.com/llvm/llvm-project/pull/76348
304 *
305 * __bdos on clang < 19.1.2 can erroneously return 0:
306 * https://github.com/llvm/llvm-project/pull/110497
307 *
308 * __bdos on clang < 19.1.3 can be off by 4:
309 * https://github.com/llvm/llvm-project/pull/112636
310 */
311 #ifdef CONFIG_CC_HAS_COUNTED_BY
312 # define __counted_by(member) __attribute__((__counted_by__(member)))
313 #else
314 # define __counted_by(member)
315 #endif
316
317 /* Section for code which can't be instrumented at all */
318 #define __noinstr_section(section) \
319 noinline notrace __attribute((__section__(section))) \
320 __no_kcsan __no_sanitize_address __no_profile __no_sanitize_coverage \
321 __no_sanitize_memory
322
323 #define noinstr __noinstr_section(".noinstr.text")
324
325 /*
326 * The __cpuidle section is used twofold:
327 *
328 * 1) the original use -- identifying if a CPU is 'stuck' in idle state based
329 * on it's instruction pointer. See cpu_in_idle().
330 *
331 * 2) supressing instrumentation around where cpuidle disables RCU; where the
332 * function isn't strictly required for #1, this is interchangeable with
333 * noinstr.
334 */
335 #define __cpuidle __noinstr_section(".cpuidle.text")
336
337 #endif /* __KERNEL__ */
338
339 #endif /* __ASSEMBLY__ */
340
341 /*
342 * The below symbols may be defined for one or more, but not ALL, of the above
343 * compilers. We don't consider that to be an error, so set them to nothing.
344 * For example, some of them are for compiler specific plugins.
345 */
346 #ifndef __latent_entropy
347 # define __latent_entropy
348 #endif
349
350 #if defined(RANDSTRUCT) && !defined(__CHECKER__)
351 # define __randomize_layout __designated_init __attribute__((randomize_layout))
352 # define __no_randomize_layout __attribute__((no_randomize_layout))
353 /* This anon struct can add padding, so only enable it under randstruct. */
354 # define randomized_struct_fields_start struct {
355 # define randomized_struct_fields_end } __randomize_layout;
356 #else
357 # define __randomize_layout __designated_init
358 # define __no_randomize_layout
359 # define randomized_struct_fields_start
360 # define randomized_struct_fields_end
361 #endif
362
363 #ifndef __noscs
364 # define __noscs
365 #endif
366
367 #ifndef __nocfi
368 # define __nocfi
369 #endif
370
371 /*
372 * Any place that could be marked with the "alloc_size" attribute is also
373 * a place to be marked with the "malloc" attribute, except those that may
374 * be performing a _reallocation_, as that may alias the existing pointer.
375 * For these, use __realloc_size().
376 */
377 #ifdef __alloc_size__
378 # define __alloc_size(x, ...) __alloc_size__(x, ## __VA_ARGS__) __malloc
379 # define __realloc_size(x, ...) __alloc_size__(x, ## __VA_ARGS__)
380 #else
381 # define __alloc_size(x, ...) __malloc
382 # define __realloc_size(x, ...)
383 #endif
384
385 /*
386 * Some versions of gcc do not mark 'asm goto' volatile:
387 *
388 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103979
389 *
390 * We do it here by hand, because it doesn't hurt.
391 */
392 #ifndef asm_goto_output
393 #define asm_goto_output(x...) asm volatile goto(x)
394 #endif
395
396 #ifdef CONFIG_CC_HAS_ASM_INLINE
397 #define asm_inline asm __inline
398 #else
399 #define asm_inline asm
400 #endif
401
402 /* Are two types/vars the same type (ignoring qualifiers)? */
403 #define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
404
405 /*
406 * __unqual_scalar_typeof(x) - Declare an unqualified scalar type, leaving
407 * non-scalar types unchanged.
408 */
409 /*
410 * Prefer C11 _Generic for better compile-times and simpler code. Note: 'char'
411 * is not type-compatible with 'signed char', and we define a separate case.
412 */
413 #define __scalar_type_to_expr_cases(type) \
414 unsigned type: (unsigned type)0, \
415 signed type: (signed type)0
416
417 #define __unqual_scalar_typeof(x) typeof( \
418 _Generic((x), \
419 char: (char)0, \
420 __scalar_type_to_expr_cases(char), \
421 __scalar_type_to_expr_cases(short), \
422 __scalar_type_to_expr_cases(int), \
423 __scalar_type_to_expr_cases(long), \
424 __scalar_type_to_expr_cases(long long), \
425 default: (x)))
426
427 /* Is this type a native word size -- useful for atomic operations */
428 #define __native_word(t) \
429 (sizeof(t) == sizeof(char) || sizeof(t) == sizeof(short) || \
430 sizeof(t) == sizeof(int) || sizeof(t) == sizeof(long))
431
432 #ifdef __OPTIMIZE__
433 # define __compiletime_assert(condition, msg, prefix, suffix) \
434 do { \
435 /* \
436 * __noreturn is needed to give the compiler enough \
437 * information to avoid certain possibly-uninitialized \
438 * warnings (regardless of the build failing). \
439 */ \
440 __noreturn extern void prefix ## suffix(void) \
441 __compiletime_error(msg); \
442 if (!(condition)) \
443 prefix ## suffix(); \
444 } while (0)
445 #else
446 # define __compiletime_assert(condition, msg, prefix, suffix) do { } while (0)
447 #endif
448
449 #define _compiletime_assert(condition, msg, prefix, suffix) \
450 __compiletime_assert(condition, msg, prefix, suffix)
451
452 /**
453 * compiletime_assert - break build and emit msg if condition is false
454 * @condition: a compile-time constant condition to check
455 * @msg: a message to emit if condition is false
456 *
457 * In tradition of POSIX assert, this macro will break the build if the
458 * supplied condition is *false*, emitting the supplied error message if the
459 * compiler has support to do so.
460 */
461 #define compiletime_assert(condition, msg) \
462 _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
463
464 #define compiletime_assert_atomic_type(t) \
465 compiletime_assert(__native_word(t), \
466 "Need native word sized stores/loads for atomicity.")
467
468 /* Helpers for emitting diagnostics in pragmas. */
469 #ifndef __diag
470 #define __diag(string)
471 #endif
472
473 #ifndef __diag_GCC
474 #define __diag_GCC(version, severity, string)
475 #endif
476
477 #define __diag_push() __diag(push)
478 #define __diag_pop() __diag(pop)
479
480 #define __diag_ignore(compiler, version, option, comment) \
481 __diag_ ## compiler(version, ignore, option)
482 #define __diag_warn(compiler, version, option, comment) \
483 __diag_ ## compiler(version, warn, option)
484 #define __diag_error(compiler, version, option, comment) \
485 __diag_ ## compiler(version, error, option)
486
487 #ifndef __diag_ignore_all
488 #define __diag_ignore_all(option, comment)
489 #endif
490
491 #endif /* __LINUX_COMPILER_TYPES_H */
492