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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