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TOMOYO Linux Cross Reference
Linux/include/linux/kernel.h

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  1 /* SPDX-License-Identifier: GPL-2.0 */
  2 #ifndef _LINUX_KERNEL_H
  3 #define _LINUX_KERNEL_H
  4 
  5 
  6 #include <stdarg.h>
  7 #include <linux/limits.h>
  8 #include <linux/linkage.h>
  9 #include <linux/stddef.h>
 10 #include <linux/types.h>
 11 #include <linux/compiler.h>
 12 #include <linux/bitops.h>
 13 #include <linux/log2.h>
 14 #include <linux/typecheck.h>
 15 #include <linux/printk.h>
 16 #include <linux/build_bug.h>
 17 #include <asm/byteorder.h>
 18 #include <asm/div64.h>
 19 #include <uapi/linux/kernel.h>
 20 #include <asm/div64.h>
 21 
 22 #define STACK_MAGIC     0xdeadbeef
 23 
 24 /**
 25  * REPEAT_BYTE - repeat the value @x multiple times as an unsigned long value
 26  * @x: value to repeat
 27  *
 28  * NOTE: @x is not checked for > 0xff; larger values produce odd results.
 29  */
 30 #define REPEAT_BYTE(x)  ((~0ul / 0xff) * (x))
 31 
 32 /* @a is a power of 2 value */
 33 #define ALIGN(x, a)             __ALIGN_KERNEL((x), (a))
 34 #define ALIGN_DOWN(x, a)        __ALIGN_KERNEL((x) - ((a) - 1), (a))
 35 #define __ALIGN_MASK(x, mask)   __ALIGN_KERNEL_MASK((x), (mask))
 36 #define PTR_ALIGN(p, a)         ((typeof(p))ALIGN((unsigned long)(p), (a)))
 37 #define IS_ALIGNED(x, a)                (((x) & ((typeof(x))(a) - 1)) == 0)
 38 
 39 /* generic data direction definitions */
 40 #define READ                    0
 41 #define WRITE                   1
 42 
 43 /**
 44  * ARRAY_SIZE - get the number of elements in array @arr
 45  * @arr: array to be sized
 46  */
 47 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
 48 
 49 #define u64_to_user_ptr(x) (            \
 50 {                                       \
 51         typecheck(u64, (x));            \
 52         (void __user *)(uintptr_t)(x);  \
 53 }                                       \
 54 )
 55 
 56 /*
 57  * This looks more complex than it should be. But we need to
 58  * get the type for the ~ right in round_down (it needs to be
 59  * as wide as the result!), and we want to evaluate the macro
 60  * arguments just once each.
 61  */
 62 #define __round_mask(x, y) ((__typeof__(x))((y)-1))
 63 /**
 64  * round_up - round up to next specified power of 2
 65  * @x: the value to round
 66  * @y: multiple to round up to (must be a power of 2)
 67  *
 68  * Rounds @x up to next multiple of @y (which must be a power of 2).
 69  * To perform arbitrary rounding up, use roundup() below.
 70  */
 71 #define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
 72 /**
 73  * round_down - round down to next specified power of 2
 74  * @x: the value to round
 75  * @y: multiple to round down to (must be a power of 2)
 76  *
 77  * Rounds @x down to next multiple of @y (which must be a power of 2).
 78  * To perform arbitrary rounding down, use rounddown() below.
 79  */
 80 #define round_down(x, y) ((x) & ~__round_mask(x, y))
 81 
 82 #define typeof_member(T, m)     typeof(((T*)0)->m)
 83 
 84 #define DIV_ROUND_UP __KERNEL_DIV_ROUND_UP
 85 
 86 #define DIV_ROUND_DOWN_ULL(ll, d) \
 87         ({ unsigned long long _tmp = (ll); do_div(_tmp, d); _tmp; })
 88 
 89 #define DIV_ROUND_UP_ULL(ll, d) \
 90         DIV_ROUND_DOWN_ULL((unsigned long long)(ll) + (d) - 1, (d))
 91 
 92 #if BITS_PER_LONG == 32
 93 # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d)
 94 #else
 95 # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP(ll,d)
 96 #endif
 97 
 98 /**
 99  * roundup - round up to the next specified multiple
100  * @x: the value to up
101  * @y: multiple to round up to
102  *
103  * Rounds @x up to next multiple of @y. If @y will always be a power
104  * of 2, consider using the faster round_up().
105  */
106 #define roundup(x, y) (                                 \
107 {                                                       \
108         typeof(y) __y = y;                              \
109         (((x) + (__y - 1)) / __y) * __y;                \
110 }                                                       \
111 )
112 /**
113  * rounddown - round down to next specified multiple
114  * @x: the value to round
115  * @y: multiple to round down to
116  *
117  * Rounds @x down to next multiple of @y. If @y will always be a power
118  * of 2, consider using the faster round_down().
119  */
120 #define rounddown(x, y) (                               \
121 {                                                       \
122         typeof(x) __x = (x);                            \
123         __x - (__x % (y));                              \
124 }                                                       \
125 )
126 
127 /*
128  * Divide positive or negative dividend by positive or negative divisor
129  * and round to closest integer. Result is undefined for negative
130  * divisors if the dividend variable type is unsigned and for negative
131  * dividends if the divisor variable type is unsigned.
132  */
133 #define DIV_ROUND_CLOSEST(x, divisor)(                  \
134 {                                                       \
135         typeof(x) __x = x;                              \
136         typeof(divisor) __d = divisor;                  \
137         (((typeof(x))-1) > 0 ||                         \
138          ((typeof(divisor))-1) > 0 ||                   \
139          (((__x) > 0) == ((__d) > 0))) ?                \
140                 (((__x) + ((__d) / 2)) / (__d)) :       \
141                 (((__x) - ((__d) / 2)) / (__d));        \
142 }                                                       \
143 )
144 /*
145  * Same as above but for u64 dividends. divisor must be a 32-bit
146  * number.
147  */
148 #define DIV_ROUND_CLOSEST_ULL(x, divisor)(              \
149 {                                                       \
150         typeof(divisor) __d = divisor;                  \
151         unsigned long long _tmp = (x) + (__d) / 2;      \
152         do_div(_tmp, __d);                              \
153         _tmp;                                           \
154 }                                                       \
155 )
156 
157 /*
158  * Multiplies an integer by a fraction, while avoiding unnecessary
159  * overflow or loss of precision.
160  */
161 #define mult_frac(x, numer, denom)(                     \
162 {                                                       \
163         typeof(x) quot = (x) / (denom);                 \
164         typeof(x) rem  = (x) % (denom);                 \
165         (quot * (numer)) + ((rem * (numer)) / (denom)); \
166 }                                                       \
167 )
168 
169 
170 #define _RET_IP_                (unsigned long)__builtin_return_address(0)
171 #define _THIS_IP_  ({ __label__ __here; __here: (unsigned long)&&__here; })
172 
173 #define sector_div(a, b) do_div(a, b)
174 
175 /**
176  * upper_32_bits - return bits 32-63 of a number
177  * @n: the number we're accessing
178  *
179  * A basic shift-right of a 64- or 32-bit quantity.  Use this to suppress
180  * the "right shift count >= width of type" warning when that quantity is
181  * 32-bits.
182  */
183 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
184 
185 /**
186  * lower_32_bits - return bits 0-31 of a number
187  * @n: the number we're accessing
188  */
189 #define lower_32_bits(n) ((u32)(n))
190 
191 struct completion;
192 struct pt_regs;
193 struct user;
194 
195 #ifdef CONFIG_PREEMPT_VOLUNTARY
196 extern int _cond_resched(void);
197 # define might_resched() _cond_resched()
198 #else
199 # define might_resched() do { } while (0)
200 #endif
201 
202 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
203 extern void ___might_sleep(const char *file, int line, int preempt_offset);
204 extern void __might_sleep(const char *file, int line, int preempt_offset);
205 extern void __cant_sleep(const char *file, int line, int preempt_offset);
206 
207 /**
208  * might_sleep - annotation for functions that can sleep
209  *
210  * this macro will print a stack trace if it is executed in an atomic
211  * context (spinlock, irq-handler, ...). Additional sections where blocking is
212  * not allowed can be annotated with non_block_start() and non_block_end()
213  * pairs.
214  *
215  * This is a useful debugging help to be able to catch problems early and not
216  * be bitten later when the calling function happens to sleep when it is not
217  * supposed to.
218  */
219 # define might_sleep() \
220         do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
221 /**
222  * cant_sleep - annotation for functions that cannot sleep
223  *
224  * this macro will print a stack trace if it is executed with preemption enabled
225  */
226 # define cant_sleep() \
227         do { __cant_sleep(__FILE__, __LINE__, 0); } while (0)
228 # define sched_annotate_sleep() (current->task_state_change = 0)
229 /**
230  * non_block_start - annotate the start of section where sleeping is prohibited
231  *
232  * This is on behalf of the oom reaper, specifically when it is calling the mmu
233  * notifiers. The problem is that if the notifier were to block on, for example,
234  * mutex_lock() and if the process which holds that mutex were to perform a
235  * sleeping memory allocation, the oom reaper is now blocked on completion of
236  * that memory allocation. Other blocking calls like wait_event() pose similar
237  * issues.
238  */
239 # define non_block_start() (current->non_block_count++)
240 /**
241  * non_block_end - annotate the end of section where sleeping is prohibited
242  *
243  * Closes a section opened by non_block_start().
244  */
245 # define non_block_end() WARN_ON(current->non_block_count-- == 0)
246 #else
247   static inline void ___might_sleep(const char *file, int line,
248                                    int preempt_offset) { }
249   static inline void __might_sleep(const char *file, int line,
250                                    int preempt_offset) { }
251 # define might_sleep() do { might_resched(); } while (0)
252 # define cant_sleep() do { } while (0)
253 # define sched_annotate_sleep() do { } while (0)
254 # define non_block_start() do { } while (0)
255 # define non_block_end() do { } while (0)
256 #endif
257 
258 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
259 
260 #ifndef CONFIG_PREEMPT_RT
261 # define cant_migrate()         cant_sleep()
262 #else
263   /* Placeholder for now */
264 # define cant_migrate()         do { } while (0)
265 #endif
266 
267 /**
268  * abs - return absolute value of an argument
269  * @x: the value.  If it is unsigned type, it is converted to signed type first.
270  *     char is treated as if it was signed (regardless of whether it really is)
271  *     but the macro's return type is preserved as char.
272  *
273  * Return: an absolute value of x.
274  */
275 #define abs(x)  __abs_choose_expr(x, long long,                         \
276                 __abs_choose_expr(x, long,                              \
277                 __abs_choose_expr(x, int,                               \
278                 __abs_choose_expr(x, short,                             \
279                 __abs_choose_expr(x, char,                              \
280                 __builtin_choose_expr(                                  \
281                         __builtin_types_compatible_p(typeof(x), char),  \
282                         (char)({ signed char __x = (x); __x<0?-__x:__x; }), \
283                         ((void)0)))))))
284 
285 #define __abs_choose_expr(x, type, other) __builtin_choose_expr(        \
286         __builtin_types_compatible_p(typeof(x),   signed type) ||       \
287         __builtin_types_compatible_p(typeof(x), unsigned type),         \
288         ({ signed type __x = (x); __x < 0 ? -__x : __x; }), other)
289 
290 /**
291  * reciprocal_scale - "scale" a value into range [0, ep_ro)
292  * @val: value
293  * @ep_ro: right open interval endpoint
294  *
295  * Perform a "reciprocal multiplication" in order to "scale" a value into
296  * range [0, @ep_ro), where the upper interval endpoint is right-open.
297  * This is useful, e.g. for accessing a index of an array containing
298  * @ep_ro elements, for example. Think of it as sort of modulus, only that
299  * the result isn't that of modulo. ;) Note that if initial input is a
300  * small value, then result will return 0.
301  *
302  * Return: a result based on @val in interval [0, @ep_ro).
303  */
304 static inline u32 reciprocal_scale(u32 val, u32 ep_ro)
305 {
306         return (u32)(((u64) val * ep_ro) >> 32);
307 }
308 
309 #if defined(CONFIG_MMU) && \
310         (defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP))
311 #define might_fault() __might_fault(__FILE__, __LINE__)
312 void __might_fault(const char *file, int line);
313 #else
314 static inline void might_fault(void) { }
315 #endif
316 
317 extern struct atomic_notifier_head panic_notifier_list;
318 extern long (*panic_blink)(int state);
319 __printf(1, 2)
320 void panic(const char *fmt, ...) __noreturn __cold;
321 void nmi_panic(struct pt_regs *regs, const char *msg);
322 extern void oops_enter(void);
323 extern void oops_exit(void);
324 void print_oops_end_marker(void);
325 extern int oops_may_print(void);
326 void do_exit(long error_code) __noreturn;
327 void complete_and_exit(struct completion *, long) __noreturn;
328 
329 /* Internal, do not use. */
330 int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res);
331 int __must_check _kstrtol(const char *s, unsigned int base, long *res);
332 
333 int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res);
334 int __must_check kstrtoll(const char *s, unsigned int base, long long *res);
335 
336 /**
337  * kstrtoul - convert a string to an unsigned long
338  * @s: The start of the string. The string must be null-terminated, and may also
339  *  include a single newline before its terminating null. The first character
340  *  may also be a plus sign, but not a minus sign.
341  * @base: The number base to use. The maximum supported base is 16. If base is
342  *  given as 0, then the base of the string is automatically detected with the
343  *  conventional semantics - If it begins with 0x the number will be parsed as a
344  *  hexadecimal (case insensitive), if it otherwise begins with 0, it will be
345  *  parsed as an octal number. Otherwise it will be parsed as a decimal.
346  * @res: Where to write the result of the conversion on success.
347  *
348  * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
349  * Used as a replacement for the simple_strtoull. Return code must be checked.
350 */
351 static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res)
352 {
353         /*
354          * We want to shortcut function call, but
355          * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0.
356          */
357         if (sizeof(unsigned long) == sizeof(unsigned long long) &&
358             __alignof__(unsigned long) == __alignof__(unsigned long long))
359                 return kstrtoull(s, base, (unsigned long long *)res);
360         else
361                 return _kstrtoul(s, base, res);
362 }
363 
364 /**
365  * kstrtol - convert a string to a long
366  * @s: The start of the string. The string must be null-terminated, and may also
367  *  include a single newline before its terminating null. The first character
368  *  may also be a plus sign or a minus sign.
369  * @base: The number base to use. The maximum supported base is 16. If base is
370  *  given as 0, then the base of the string is automatically detected with the
371  *  conventional semantics - If it begins with 0x the number will be parsed as a
372  *  hexadecimal (case insensitive), if it otherwise begins with 0, it will be
373  *  parsed as an octal number. Otherwise it will be parsed as a decimal.
374  * @res: Where to write the result of the conversion on success.
375  *
376  * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
377  * Used as a replacement for the simple_strtoull. Return code must be checked.
378  */
379 static inline int __must_check kstrtol(const char *s, unsigned int base, long *res)
380 {
381         /*
382          * We want to shortcut function call, but
383          * __builtin_types_compatible_p(long, long long) = 0.
384          */
385         if (sizeof(long) == sizeof(long long) &&
386             __alignof__(long) == __alignof__(long long))
387                 return kstrtoll(s, base, (long long *)res);
388         else
389                 return _kstrtol(s, base, res);
390 }
391 
392 int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res);
393 int __must_check kstrtoint(const char *s, unsigned int base, int *res);
394 
395 static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res)
396 {
397         return kstrtoull(s, base, res);
398 }
399 
400 static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res)
401 {
402         return kstrtoll(s, base, res);
403 }
404 
405 static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res)
406 {
407         return kstrtouint(s, base, res);
408 }
409 
410 static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res)
411 {
412         return kstrtoint(s, base, res);
413 }
414 
415 int __must_check kstrtou16(const char *s, unsigned int base, u16 *res);
416 int __must_check kstrtos16(const char *s, unsigned int base, s16 *res);
417 int __must_check kstrtou8(const char *s, unsigned int base, u8 *res);
418 int __must_check kstrtos8(const char *s, unsigned int base, s8 *res);
419 int __must_check kstrtobool(const char *s, bool *res);
420 
421 int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res);
422 int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res);
423 int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res);
424 int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res);
425 int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res);
426 int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res);
427 int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res);
428 int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res);
429 int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res);
430 int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res);
431 int __must_check kstrtobool_from_user(const char __user *s, size_t count, bool *res);
432 
433 static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res)
434 {
435         return kstrtoull_from_user(s, count, base, res);
436 }
437 
438 static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res)
439 {
440         return kstrtoll_from_user(s, count, base, res);
441 }
442 
443 static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res)
444 {
445         return kstrtouint_from_user(s, count, base, res);
446 }
447 
448 static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res)
449 {
450         return kstrtoint_from_user(s, count, base, res);
451 }
452 
453 /*
454  * Use kstrto<foo> instead.
455  *
456  * NOTE: simple_strto<foo> does not check for the range overflow and,
457  *       depending on the input, may give interesting results.
458  *
459  * Use these functions if and only if you cannot use kstrto<foo>, because
460  * the conversion ends on the first non-digit character, which may be far
461  * beyond the supported range. It might be useful to parse the strings like
462  * 10x50 or 12:21 without altering original string or temporary buffer in use.
463  * Keep in mind above caveat.
464  */
465 
466 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
467 extern long simple_strtol(const char *,char **,unsigned int);
468 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
469 extern long long simple_strtoll(const char *,char **,unsigned int);
470 
471 extern int num_to_str(char *buf, int size,
472                       unsigned long long num, unsigned int width);
473 
474 /* lib/printf utilities */
475 
476 extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...);
477 extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list);
478 extern __printf(3, 4)
479 int snprintf(char *buf, size_t size, const char *fmt, ...);
480 extern __printf(3, 0)
481 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args);
482 extern __printf(3, 4)
483 int scnprintf(char *buf, size_t size, const char *fmt, ...);
484 extern __printf(3, 0)
485 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args);
486 extern __printf(2, 3) __malloc
487 char *kasprintf(gfp_t gfp, const char *fmt, ...);
488 extern __printf(2, 0) __malloc
489 char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
490 extern __printf(2, 0)
491 const char *kvasprintf_const(gfp_t gfp, const char *fmt, va_list args);
492 
493 extern __scanf(2, 3)
494 int sscanf(const char *, const char *, ...);
495 extern __scanf(2, 0)
496 int vsscanf(const char *, const char *, va_list);
497 
498 extern int get_option(char **str, int *pint);
499 extern char *get_options(const char *str, int nints, int *ints);
500 extern unsigned long long memparse(const char *ptr, char **retptr);
501 extern bool parse_option_str(const char *str, const char *option);
502 extern char *next_arg(char *args, char **param, char **val);
503 
504 extern int core_kernel_text(unsigned long addr);
505 extern int init_kernel_text(unsigned long addr);
506 extern int core_kernel_data(unsigned long addr);
507 extern int __kernel_text_address(unsigned long addr);
508 extern int kernel_text_address(unsigned long addr);
509 extern int func_ptr_is_kernel_text(void *ptr);
510 
511 u64 int_pow(u64 base, unsigned int exp);
512 unsigned long int_sqrt(unsigned long);
513 
514 #if BITS_PER_LONG < 64
515 u32 int_sqrt64(u64 x);
516 #else
517 static inline u32 int_sqrt64(u64 x)
518 {
519         return (u32)int_sqrt(x);
520 }
521 #endif
522 
523 #ifdef CONFIG_SMP
524 extern unsigned int sysctl_oops_all_cpu_backtrace;
525 #else
526 #define sysctl_oops_all_cpu_backtrace 0
527 #endif /* CONFIG_SMP */
528 
529 extern void bust_spinlocks(int yes);
530 extern int oops_in_progress;            /* If set, an oops, panic(), BUG() or die() is in progress */
531 extern int panic_timeout;
532 extern unsigned long panic_print;
533 extern int panic_on_oops;
534 extern int panic_on_unrecovered_nmi;
535 extern int panic_on_io_nmi;
536 extern int panic_on_warn;
537 extern unsigned long panic_on_taint;
538 extern bool panic_on_taint_nousertaint;
539 extern int sysctl_panic_on_rcu_stall;
540 extern int sysctl_panic_on_stackoverflow;
541 
542 extern bool crash_kexec_post_notifiers;
543 
544 /*
545  * panic_cpu is used for synchronizing panic() and crash_kexec() execution. It
546  * holds a CPU number which is executing panic() currently. A value of
547  * PANIC_CPU_INVALID means no CPU has entered panic() or crash_kexec().
548  */
549 extern atomic_t panic_cpu;
550 #define PANIC_CPU_INVALID       -1
551 
552 /*
553  * Only to be used by arch init code. If the user over-wrote the default
554  * CONFIG_PANIC_TIMEOUT, honor it.
555  */
556 static inline void set_arch_panic_timeout(int timeout, int arch_default_timeout)
557 {
558         if (panic_timeout == arch_default_timeout)
559                 panic_timeout = timeout;
560 }
561 extern const char *print_tainted(void);
562 enum lockdep_ok {
563         LOCKDEP_STILL_OK,
564         LOCKDEP_NOW_UNRELIABLE
565 };
566 extern void add_taint(unsigned flag, enum lockdep_ok);
567 extern int test_taint(unsigned flag);
568 extern unsigned long get_taint(void);
569 extern int root_mountflags;
570 
571 extern bool early_boot_irqs_disabled;
572 
573 /*
574  * Values used for system_state. Ordering of the states must not be changed
575  * as code checks for <, <=, >, >= STATE.
576  */
577 extern enum system_states {
578         SYSTEM_BOOTING,
579         SYSTEM_SCHEDULING,
580         SYSTEM_RUNNING,
581         SYSTEM_HALT,
582         SYSTEM_POWER_OFF,
583         SYSTEM_RESTART,
584         SYSTEM_SUSPEND,
585 } system_state;
586 
587 /* This cannot be an enum because some may be used in assembly source. */
588 #define TAINT_PROPRIETARY_MODULE        0
589 #define TAINT_FORCED_MODULE             1
590 #define TAINT_CPU_OUT_OF_SPEC           2
591 #define TAINT_FORCED_RMMOD              3
592 #define TAINT_MACHINE_CHECK             4
593 #define TAINT_BAD_PAGE                  5
594 #define TAINT_USER                      6
595 #define TAINT_DIE                       7
596 #define TAINT_OVERRIDDEN_ACPI_TABLE     8
597 #define TAINT_WARN                      9
598 #define TAINT_CRAP                      10
599 #define TAINT_FIRMWARE_WORKAROUND       11
600 #define TAINT_OOT_MODULE                12
601 #define TAINT_UNSIGNED_MODULE           13
602 #define TAINT_SOFTLOCKUP                14
603 #define TAINT_LIVEPATCH                 15
604 #define TAINT_AUX                       16
605 #define TAINT_RANDSTRUCT                17
606 #define TAINT_FLAGS_COUNT               18
607 #define TAINT_FLAGS_MAX                 ((1UL << TAINT_FLAGS_COUNT) - 1)
608 
609 struct taint_flag {
610         char c_true;    /* character printed when tainted */
611         char c_false;   /* character printed when not tainted */
612         bool module;    /* also show as a per-module taint flag */
613 };
614 
615 extern const struct taint_flag taint_flags[TAINT_FLAGS_COUNT];
616 
617 extern const char hex_asc[];
618 #define hex_asc_lo(x)   hex_asc[((x) & 0x0f)]
619 #define hex_asc_hi(x)   hex_asc[((x) & 0xf0) >> 4]
620 
621 static inline char *hex_byte_pack(char *buf, u8 byte)
622 {
623         *buf++ = hex_asc_hi(byte);
624         *buf++ = hex_asc_lo(byte);
625         return buf;
626 }
627 
628 extern const char hex_asc_upper[];
629 #define hex_asc_upper_lo(x)     hex_asc_upper[((x) & 0x0f)]
630 #define hex_asc_upper_hi(x)     hex_asc_upper[((x) & 0xf0) >> 4]
631 
632 static inline char *hex_byte_pack_upper(char *buf, u8 byte)
633 {
634         *buf++ = hex_asc_upper_hi(byte);
635         *buf++ = hex_asc_upper_lo(byte);
636         return buf;
637 }
638 
639 extern int hex_to_bin(char ch);
640 extern int __must_check hex2bin(u8 *dst, const char *src, size_t count);
641 extern char *bin2hex(char *dst, const void *src, size_t count);
642 
643 bool mac_pton(const char *s, u8 *mac);
644 
645 /*
646  * General tracing related utility functions - trace_printk(),
647  * tracing_on/tracing_off and tracing_start()/tracing_stop
648  *
649  * Use tracing_on/tracing_off when you want to quickly turn on or off
650  * tracing. It simply enables or disables the recording of the trace events.
651  * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
652  * file, which gives a means for the kernel and userspace to interact.
653  * Place a tracing_off() in the kernel where you want tracing to end.
654  * From user space, examine the trace, and then echo 1 > tracing_on
655  * to continue tracing.
656  *
657  * tracing_stop/tracing_start has slightly more overhead. It is used
658  * by things like suspend to ram where disabling the recording of the
659  * trace is not enough, but tracing must actually stop because things
660  * like calling smp_processor_id() may crash the system.
661  *
662  * Most likely, you want to use tracing_on/tracing_off.
663  */
664 
665 enum ftrace_dump_mode {
666         DUMP_NONE,
667         DUMP_ALL,
668         DUMP_ORIG,
669 };
670 
671 #ifdef CONFIG_TRACING
672 void tracing_on(void);
673 void tracing_off(void);
674 int tracing_is_on(void);
675 void tracing_snapshot(void);
676 void tracing_snapshot_alloc(void);
677 
678 extern void tracing_start(void);
679 extern void tracing_stop(void);
680 
681 static inline __printf(1, 2)
682 void ____trace_printk_check_format(const char *fmt, ...)
683 {
684 }
685 #define __trace_printk_check_format(fmt, args...)                       \
686 do {                                                                    \
687         if (0)                                                          \
688                 ____trace_printk_check_format(fmt, ##args);             \
689 } while (0)
690 
691 /**
692  * trace_printk - printf formatting in the ftrace buffer
693  * @fmt: the printf format for printing
694  *
695  * Note: __trace_printk is an internal function for trace_printk() and
696  *       the @ip is passed in via the trace_printk() macro.
697  *
698  * This function allows a kernel developer to debug fast path sections
699  * that printk is not appropriate for. By scattering in various
700  * printk like tracing in the code, a developer can quickly see
701  * where problems are occurring.
702  *
703  * This is intended as a debugging tool for the developer only.
704  * Please refrain from leaving trace_printks scattered around in
705  * your code. (Extra memory is used for special buffers that are
706  * allocated when trace_printk() is used.)
707  *
708  * A little optimization trick is done here. If there's only one
709  * argument, there's no need to scan the string for printf formats.
710  * The trace_puts() will suffice. But how can we take advantage of
711  * using trace_puts() when trace_printk() has only one argument?
712  * By stringifying the args and checking the size we can tell
713  * whether or not there are args. __stringify((__VA_ARGS__)) will
714  * turn into "()\0" with a size of 3 when there are no args, anything
715  * else will be bigger. All we need to do is define a string to this,
716  * and then take its size and compare to 3. If it's bigger, use
717  * do_trace_printk() otherwise, optimize it to trace_puts(). Then just
718  * let gcc optimize the rest.
719  */
720 
721 #define trace_printk(fmt, ...)                          \
722 do {                                                    \
723         char _______STR[] = __stringify((__VA_ARGS__)); \
724         if (sizeof(_______STR) > 3)                     \
725                 do_trace_printk(fmt, ##__VA_ARGS__);    \
726         else                                            \
727                 trace_puts(fmt);                        \
728 } while (0)
729 
730 #define do_trace_printk(fmt, args...)                                   \
731 do {                                                                    \
732         static const char *trace_printk_fmt __used                      \
733                 __attribute__((section("__trace_printk_fmt"))) =        \
734                 __builtin_constant_p(fmt) ? fmt : NULL;                 \
735                                                                         \
736         __trace_printk_check_format(fmt, ##args);                       \
737                                                                         \
738         if (__builtin_constant_p(fmt))                                  \
739                 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args);   \
740         else                                                            \
741                 __trace_printk(_THIS_IP_, fmt, ##args);                 \
742 } while (0)
743 
744 extern __printf(2, 3)
745 int __trace_bprintk(unsigned long ip, const char *fmt, ...);
746 
747 extern __printf(2, 3)
748 int __trace_printk(unsigned long ip, const char *fmt, ...);
749 
750 /**
751  * trace_puts - write a string into the ftrace buffer
752  * @str: the string to record
753  *
754  * Note: __trace_bputs is an internal function for trace_puts and
755  *       the @ip is passed in via the trace_puts macro.
756  *
757  * This is similar to trace_printk() but is made for those really fast
758  * paths that a developer wants the least amount of "Heisenbug" effects,
759  * where the processing of the print format is still too much.
760  *
761  * This function allows a kernel developer to debug fast path sections
762  * that printk is not appropriate for. By scattering in various
763  * printk like tracing in the code, a developer can quickly see
764  * where problems are occurring.
765  *
766  * This is intended as a debugging tool for the developer only.
767  * Please refrain from leaving trace_puts scattered around in
768  * your code. (Extra memory is used for special buffers that are
769  * allocated when trace_puts() is used.)
770  *
771  * Returns: 0 if nothing was written, positive # if string was.
772  *  (1 when __trace_bputs is used, strlen(str) when __trace_puts is used)
773  */
774 
775 #define trace_puts(str) ({                                              \
776         static const char *trace_printk_fmt __used                      \
777                 __attribute__((section("__trace_printk_fmt"))) =        \
778                 __builtin_constant_p(str) ? str : NULL;                 \
779                                                                         \
780         if (__builtin_constant_p(str))                                  \
781                 __trace_bputs(_THIS_IP_, trace_printk_fmt);             \
782         else                                                            \
783                 __trace_puts(_THIS_IP_, str, strlen(str));              \
784 })
785 extern int __trace_bputs(unsigned long ip, const char *str);
786 extern int __trace_puts(unsigned long ip, const char *str, int size);
787 
788 extern void trace_dump_stack(int skip);
789 
790 /*
791  * The double __builtin_constant_p is because gcc will give us an error
792  * if we try to allocate the static variable to fmt if it is not a
793  * constant. Even with the outer if statement.
794  */
795 #define ftrace_vprintk(fmt, vargs)                                      \
796 do {                                                                    \
797         if (__builtin_constant_p(fmt)) {                                \
798                 static const char *trace_printk_fmt __used              \
799                   __attribute__((section("__trace_printk_fmt"))) =      \
800                         __builtin_constant_p(fmt) ? fmt : NULL;         \
801                                                                         \
802                 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs);  \
803         } else                                                          \
804                 __ftrace_vprintk(_THIS_IP_, fmt, vargs);                \
805 } while (0)
806 
807 extern __printf(2, 0) int
808 __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
809 
810 extern __printf(2, 0) int
811 __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
812 
813 extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
814 #else
815 static inline void tracing_start(void) { }
816 static inline void tracing_stop(void) { }
817 static inline void trace_dump_stack(int skip) { }
818 
819 static inline void tracing_on(void) { }
820 static inline void tracing_off(void) { }
821 static inline int tracing_is_on(void) { return 0; }
822 static inline void tracing_snapshot(void) { }
823 static inline void tracing_snapshot_alloc(void) { }
824 
825 static inline __printf(1, 2)
826 int trace_printk(const char *fmt, ...)
827 {
828         return 0;
829 }
830 static __printf(1, 0) inline int
831 ftrace_vprintk(const char *fmt, va_list ap)
832 {
833         return 0;
834 }
835 static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
836 #endif /* CONFIG_TRACING */
837 
838 /*
839  * min()/max()/clamp() macros must accomplish three things:
840  *
841  * - avoid multiple evaluations of the arguments (so side-effects like
842  *   "x++" happen only once) when non-constant.
843  * - perform strict type-checking (to generate warnings instead of
844  *   nasty runtime surprises). See the "unnecessary" pointer comparison
845  *   in __typecheck().
846  * - retain result as a constant expressions when called with only
847  *   constant expressions (to avoid tripping VLA warnings in stack
848  *   allocation usage).
849  */
850 #define __typecheck(x, y) \
851                 (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
852 
853 /*
854  * This returns a constant expression while determining if an argument is
855  * a constant expression, most importantly without evaluating the argument.
856  * Glory to Martin Uecker <Martin.Uecker@med.uni-goettingen.de>
857  */
858 #define __is_constexpr(x) \
859         (sizeof(int) == sizeof(*(8 ? ((void *)((long)(x) * 0l)) : (int *)8)))
860 
861 #define __no_side_effects(x, y) \
862                 (__is_constexpr(x) && __is_constexpr(y))
863 
864 #define __safe_cmp(x, y) \
865                 (__typecheck(x, y) && __no_side_effects(x, y))
866 
867 #define __cmp(x, y, op) ((x) op (y) ? (x) : (y))
868 
869 #define __cmp_once(x, y, unique_x, unique_y, op) ({     \
870                 typeof(x) unique_x = (x);               \
871                 typeof(y) unique_y = (y);               \
872                 __cmp(unique_x, unique_y, op); })
873 
874 #define __careful_cmp(x, y, op) \
875         __builtin_choose_expr(__safe_cmp(x, y), \
876                 __cmp(x, y, op), \
877                 __cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y), op))
878 
879 /**
880  * min - return minimum of two values of the same or compatible types
881  * @x: first value
882  * @y: second value
883  */
884 #define min(x, y)       __careful_cmp(x, y, <)
885 
886 /**
887  * max - return maximum of two values of the same or compatible types
888  * @x: first value
889  * @y: second value
890  */
891 #define max(x, y)       __careful_cmp(x, y, >)
892 
893 /**
894  * min3 - return minimum of three values
895  * @x: first value
896  * @y: second value
897  * @z: third value
898  */
899 #define min3(x, y, z) min((typeof(x))min(x, y), z)
900 
901 /**
902  * max3 - return maximum of three values
903  * @x: first value
904  * @y: second value
905  * @z: third value
906  */
907 #define max3(x, y, z) max((typeof(x))max(x, y), z)
908 
909 /**
910  * min_not_zero - return the minimum that is _not_ zero, unless both are zero
911  * @x: value1
912  * @y: value2
913  */
914 #define min_not_zero(x, y) ({                   \
915         typeof(x) __x = (x);                    \
916         typeof(y) __y = (y);                    \
917         __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); })
918 
919 /**
920  * clamp - return a value clamped to a given range with strict typechecking
921  * @val: current value
922  * @lo: lowest allowable value
923  * @hi: highest allowable value
924  *
925  * This macro does strict typechecking of @lo/@hi to make sure they are of the
926  * same type as @val.  See the unnecessary pointer comparisons.
927  */
928 #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi)
929 
930 /*
931  * ..and if you can't take the strict
932  * types, you can specify one yourself.
933  *
934  * Or not use min/max/clamp at all, of course.
935  */
936 
937 /**
938  * min_t - return minimum of two values, using the specified type
939  * @type: data type to use
940  * @x: first value
941  * @y: second value
942  */
943 #define min_t(type, x, y)       __careful_cmp((type)(x), (type)(y), <)
944 
945 /**
946  * max_t - return maximum of two values, using the specified type
947  * @type: data type to use
948  * @x: first value
949  * @y: second value
950  */
951 #define max_t(type, x, y)       __careful_cmp((type)(x), (type)(y), >)
952 
953 /**
954  * clamp_t - return a value clamped to a given range using a given type
955  * @type: the type of variable to use
956  * @val: current value
957  * @lo: minimum allowable value
958  * @hi: maximum allowable value
959  *
960  * This macro does no typechecking and uses temporary variables of type
961  * @type to make all the comparisons.
962  */
963 #define clamp_t(type, val, lo, hi) min_t(type, max_t(type, val, lo), hi)
964 
965 /**
966  * clamp_val - return a value clamped to a given range using val's type
967  * @val: current value
968  * @lo: minimum allowable value
969  * @hi: maximum allowable value
970  *
971  * This macro does no typechecking and uses temporary variables of whatever
972  * type the input argument @val is.  This is useful when @val is an unsigned
973  * type and @lo and @hi are literals that will otherwise be assigned a signed
974  * integer type.
975  */
976 #define clamp_val(val, lo, hi) clamp_t(typeof(val), val, lo, hi)
977 
978 
979 /**
980  * swap - swap values of @a and @b
981  * @a: first value
982  * @b: second value
983  */
984 #define swap(a, b) \
985         do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
986 
987 /* This counts to 12. Any more, it will return 13th argument. */
988 #define __COUNT_ARGS(_0, _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _n, X...) _n
989 #define COUNT_ARGS(X...) __COUNT_ARGS(, ##X, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
990 
991 #define __CONCAT(a, b) a ## b
992 #define CONCATENATE(a, b) __CONCAT(a, b)
993 
994 /**
995  * container_of - cast a member of a structure out to the containing structure
996  * @ptr:        the pointer to the member.
997  * @type:       the type of the container struct this is embedded in.
998  * @member:     the name of the member within the struct.
999  *
1000  */
1001 #define container_of(ptr, type, member) ({                              \
1002         void *__mptr = (void *)(ptr);                                   \
1003         BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) &&   \
1004                          !__same_type(*(ptr), void),                    \
1005                          "pointer type mismatch in container_of()");    \
1006         ((type *)(__mptr - offsetof(type, member))); })
1007 
1008 /**
1009  * container_of_safe - cast a member of a structure out to the containing structure
1010  * @ptr:        the pointer to the member.
1011  * @type:       the type of the container struct this is embedded in.
1012  * @member:     the name of the member within the struct.
1013  *
1014  * If IS_ERR_OR_NULL(ptr), ptr is returned unchanged.
1015  */
1016 #define container_of_safe(ptr, type, member) ({                         \
1017         void *__mptr = (void *)(ptr);                                   \
1018         BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) &&   \
1019                          !__same_type(*(ptr), void),                    \
1020                          "pointer type mismatch in container_of()");    \
1021         IS_ERR_OR_NULL(__mptr) ? ERR_CAST(__mptr) :                     \
1022                 ((type *)(__mptr - offsetof(type, member))); })
1023 
1024 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
1025 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
1026 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
1027 #endif
1028 
1029 /* Permissions on a sysfs file: you didn't miss the 0 prefix did you? */
1030 #define VERIFY_OCTAL_PERMISSIONS(perms)                                         \
1031         (BUILD_BUG_ON_ZERO((perms) < 0) +                                       \
1032          BUILD_BUG_ON_ZERO((perms) > 0777) +                                    \
1033          /* USER_READABLE >= GROUP_READABLE >= OTHER_READABLE */                \
1034          BUILD_BUG_ON_ZERO((((perms) >> 6) & 4) < (((perms) >> 3) & 4)) +       \
1035          BUILD_BUG_ON_ZERO((((perms) >> 3) & 4) < ((perms) & 4)) +              \
1036          /* USER_WRITABLE >= GROUP_WRITABLE */                                  \
1037          BUILD_BUG_ON_ZERO((((perms) >> 6) & 2) < (((perms) >> 3) & 2)) +       \
1038          /* OTHER_WRITABLE?  Generally considered a bad idea. */                \
1039          BUILD_BUG_ON_ZERO((perms) & 2) +                                       \
1040          (perms))
1041 #endif
1042 

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