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

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