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 #ifndef __no_sanitize_or_inline
284 #define __no_sanitize_or_inline __always_inline
285 #endif
286 
287 /* Section for code which can't be instrumented at all */
288 #define __noinstr_section(section)					\
289 	noinline notrace __attribute((__section__(section)))		\
290 	__no_kcsan __no_sanitize_address __no_profile __no_sanitize_coverage \
291 	__no_sanitize_memory
292 
293 #define noinstr __noinstr_section(".noinstr.text")
294 
295 /*
296  * The __cpuidle section is used twofold:
297  *
298  *  1) the original use -- identifying if a CPU is 'stuck' in idle state based
299  *     on it's instruction pointer. See cpu_in_idle().
300  *
301  *  2) supressing instrumentation around where cpuidle disables RCU; where the
302  *     function isn't strictly required for #1, this is interchangeable with
303  *     noinstr.
304  */
305 #define __cpuidle __noinstr_section(".cpuidle.text")
306 
307 #endif /* __KERNEL__ */
308 
309 #endif /* __ASSEMBLY__ */
310 
311 /*
312  * The below symbols may be defined for one or more, but not ALL, of the above
313  * compilers. We don't consider that to be an error, so set them to nothing.
314  * For example, some of them are for compiler specific plugins.
315  */
316 #ifndef __latent_entropy
317 # define __latent_entropy
318 #endif
319 
320 #if defined(RANDSTRUCT) && !defined(__CHECKER__)
321 # define __randomize_layout __designated_init __attribute__((randomize_layout))
322 # define __no_randomize_layout __attribute__((no_randomize_layout))
323 /* This anon struct can add padding, so only enable it under randstruct. */
324 # define randomized_struct_fields_start	struct {
325 # define randomized_struct_fields_end	} __randomize_layout;
326 #else
327 # define __randomize_layout __designated_init
328 # define __no_randomize_layout
329 # define randomized_struct_fields_start
330 # define randomized_struct_fields_end
331 #endif
332 
333 #ifndef __noscs
334 # define __noscs
335 #endif
336 
337 #ifndef __nocfi
338 # define __nocfi
339 #endif
340 
341 /*
342  * Any place that could be marked with the "alloc_size" attribute is also
343  * a place to be marked with the "malloc" attribute, except those that may
344  * be performing a _reallocation_, as that may alias the existing pointer.
345  * For these, use __realloc_size().
346  */
347 #ifdef __alloc_size__
348 # define __alloc_size(x, ...)	__alloc_size__(x, ## __VA_ARGS__) __malloc
349 # define __realloc_size(x, ...)	__alloc_size__(x, ## __VA_ARGS__)
350 #else
351 # define __alloc_size(x, ...)	__malloc
352 # define __realloc_size(x, ...)
353 #endif
354 
355 /*
356  * Some versions of gcc do not mark 'asm goto' volatile:
357  *
358  *  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103979
359  *
360  * We do it here by hand, because it doesn't hurt.
361  */
362 #ifndef asm_goto_output
363 #define asm_goto_output(x...) asm volatile goto(x)
364 #endif
365 
366 #ifdef CONFIG_CC_HAS_ASM_INLINE
367 #define asm_inline asm __inline
368 #else
369 #define asm_inline asm
370 #endif
371 
372 /* Are two types/vars the same type (ignoring qualifiers)? */
373 #define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
374 
375 /*
376  * __unqual_scalar_typeof(x) - Declare an unqualified scalar type, leaving
377  *			       non-scalar types unchanged.
378  */
379 /*
380  * Prefer C11 _Generic for better compile-times and simpler code. Note: 'char'
381  * is not type-compatible with 'signed char', and we define a separate case.
382  */
383 #define __scalar_type_to_expr_cases(type)				\
384 		unsigned type:	(unsigned type)0,			\
385 		signed type:	(signed type)0
386 
387 #define __unqual_scalar_typeof(x) typeof(				\
388 		_Generic((x),						\
389 			 char:	(char)0,				\
390 			 __scalar_type_to_expr_cases(char),		\
391 			 __scalar_type_to_expr_cases(short),		\
392 			 __scalar_type_to_expr_cases(int),		\
393 			 __scalar_type_to_expr_cases(long),		\
394 			 __scalar_type_to_expr_cases(long long),	\
395 			 default: (x)))
396 
397 /* Is this type a native word size -- useful for atomic operations */
398 #define __native_word(t) \
399 	(sizeof(t) == sizeof(char) || sizeof(t) == sizeof(short) || \
400 	 sizeof(t) == sizeof(int) || sizeof(t) == sizeof(long))
401 
402 #ifdef __OPTIMIZE__
403 # define __compiletime_assert(condition, msg, prefix, suffix)		\
404 	do {								\
405 		/*							\
406 		 * __noreturn is needed to give the compiler enough	\
407 		 * information to avoid certain possibly-uninitialized	\
408 		 * warnings (regardless of the build failing).		\
409 		 */							\
410 		__noreturn extern void prefix ## suffix(void)		\
411 			__compiletime_error(msg);			\
412 		if (!(condition))					\
413 			prefix ## suffix();				\
414 	} while (0)
415 #else
416 # define __compiletime_assert(condition, msg, prefix, suffix) do { } while (0)
417 #endif
418 
419 #define _compiletime_assert(condition, msg, prefix, suffix) \
420 	__compiletime_assert(condition, msg, prefix, suffix)
421 
422 /**
423  * compiletime_assert - break build and emit msg if condition is false
424  * @condition: a compile-time constant condition to check
425  * @msg:       a message to emit if condition is false
426  *
427  * In tradition of POSIX assert, this macro will break the build if the
428  * supplied condition is *false*, emitting the supplied error message if the
429  * compiler has support to do so.
430  */
431 #define compiletime_assert(condition, msg) \
432 	_compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
433 
434 #define compiletime_assert_atomic_type(t)				\
435 	compiletime_assert(__native_word(t),				\
436 		"Need native word sized stores/loads for atomicity.")
437 
438 /* Helpers for emitting diagnostics in pragmas. */
439 #ifndef __diag
440 #define __diag(string)
441 #endif
442 
443 #ifndef __diag_GCC
444 #define __diag_GCC(version, severity, string)
445 #endif
446 
447 #define __diag_push()	__diag(push)
448 #define __diag_pop()	__diag(pop)
449 
450 #define __diag_ignore(compiler, version, option, comment) \
451 	__diag_ ## compiler(version, ignore, option)
452 #define __diag_warn(compiler, version, option, comment) \
453 	__diag_ ## compiler(version, warn, option)
454 #define __diag_error(compiler, version, option, comment) \
455 	__diag_ ## compiler(version, error, option)
456 
457 #ifndef __diag_ignore_all
458 #define __diag_ignore_all(option, comment)
459 #endif
460 
461 #endif /* __LINUX_COMPILER_TYPES_H */
462