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/linkage.h>
8 #include <linux/stddef.h>
9 #include <linux/types.h>
10 #include <linux/compiler.h>
11 #include <linux/bitops.h>
12 #include <linux/log2.h>
13 #include <linux/typecheck.h>
14 #include <linux/printk.h>
15 #include <linux/build_bug.h>
16 #include <asm/byteorder.h>
17 #include <uapi/linux/kernel.h>
18
19 #define USHRT_MAX ((u16)(~0U))
20 #define SHRT_MAX ((s16)(USHRT_MAX>>1))
21 #define SHRT_MIN ((s16)(-SHRT_MAX - 1))
22 #define INT_MAX ((int)(~0U>>1))
23 #define INT_MIN (-INT_MAX - 1)
24 #define UINT_MAX (~0U)
25 #define LONG_MAX ((long)(~0UL>>1))
26 #define LONG_MIN (-LONG_MAX - 1)
27 #define ULONG_MAX (~0UL)
28 #define LLONG_MAX ((long long)(~0ULL>>1))
29 #define LLONG_MIN (-LLONG_MAX - 1)
30 #define ULLONG_MAX (~0ULL)
31 #define SIZE_MAX (~(size_t)0)
32
33 #define U8_MAX ((u8)~0U)
34 #define S8_MAX ((s8)(U8_MAX>>1))
35 #define S8_MIN ((s8)(-S8_MAX - 1))
36 #define U16_MAX ((u16)~0U)
37 #define S16_MAX ((s16)(U16_MAX>>1))
38 #define S16_MIN ((s16)(-S16_MAX - 1))
39 #define U32_MAX ((u32)~0U)
40 #define S32_MAX ((s32)(U32_MAX>>1))
41 #define S32_MIN ((s32)(-S32_MAX - 1))
42 #define U64_MAX ((u64)~0ULL)
43 #define S64_MAX ((s64)(U64_MAX>>1))
44 #define S64_MIN ((s64)(-S64_MAX - 1))
45
46 #define STACK_MAGIC 0xdeadbeef
47
48 /**
49 * REPEAT_BYTE - repeat the value @x multiple times as an unsigned long value
50 * @x: value to repeat
51 *
52 * NOTE: @x is not checked for > 0xff; larger values produce odd results.
53 */
54 #define REPEAT_BYTE(x) ((~0ul / 0xff) * (x))
55
56 /* @a is a power of 2 value */
57 #define ALIGN(x, a) __ALIGN_KERNEL((x), (a))
58 #define ALIGN_DOWN(x, a) __ALIGN_KERNEL((x) - ((a) - 1), (a))
59 #define __ALIGN_MASK(x, mask) __ALIGN_KERNEL_MASK((x), (mask))
60 #define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a)))
61 #define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0)
62
63 /* generic data direction definitions */
64 #define READ 0
65 #define WRITE 1
66
67 /**
68 * ARRAY_SIZE - get the number of elements in array @arr
69 * @arr: array to be sized
70 */
71 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
72
73 #define u64_to_user_ptr(x) ( \
74 { \
75 typecheck(u64, x); \
76 (void __user *)(uintptr_t)x; \
77 } \
78 )
79
80 /*
81 * This looks more complex than it should be. But we need to
82 * get the type for the ~ right in round_down (it needs to be
83 * as wide as the result!), and we want to evaluate the macro
84 * arguments just once each.
85 */
86 #define __round_mask(x, y) ((__typeof__(x))((y)-1))
87 #define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
88 #define round_down(x, y) ((x) & ~__round_mask(x, y))
89
90 /**
91 * FIELD_SIZEOF - get the size of a struct's field
92 * @t: the target struct
93 * @f: the target struct's field
94 * Return: the size of @f in the struct definition without having a
95 * declared instance of @t.
96 */
97 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
98
99 #define DIV_ROUND_UP __KERNEL_DIV_ROUND_UP
100
101 #define DIV_ROUND_DOWN_ULL(ll, d) \
102 ({ unsigned long long _tmp = (ll); do_div(_tmp, d); _tmp; })
103
104 #define DIV_ROUND_UP_ULL(ll, d) DIV_ROUND_DOWN_ULL((ll) + (d) - 1, (d))
105
106 #if BITS_PER_LONG == 32
107 # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d)
108 #else
109 # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP(ll,d)
110 #endif
111
112 /* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */
113 #define roundup(x, y) ( \
114 { \
115 const typeof(y) __y = y; \
116 (((x) + (__y - 1)) / __y) * __y; \
117 } \
118 )
119 #define rounddown(x, y) ( \
120 { \
121 typeof(x) __x = (x); \
122 __x - (__x % (y)); \
123 } \
124 )
125
126 /*
127 * Divide positive or negative dividend by positive or negative divisor
128 * and round to closest integer. Result is undefined for negative
129 * divisors if the dividend variable type is unsigned and for negative
130 * dividends if the divisor variable type is unsigned.
131 */
132 #define DIV_ROUND_CLOSEST(x, divisor)( \
133 { \
134 typeof(x) __x = x; \
135 typeof(divisor) __d = divisor; \
136 (((typeof(x))-1) > 0 || \
137 ((typeof(divisor))-1) > 0 || \
138 (((__x) > 0) == ((__d) > 0))) ? \
139 (((__x) + ((__d) / 2)) / (__d)) : \
140 (((__x) - ((__d) / 2)) / (__d)); \
141 } \
142 )
143 /*
144 * Same as above but for u64 dividends. divisor must be a 32-bit
145 * number.
146 */
147 #define DIV_ROUND_CLOSEST_ULL(x, divisor)( \
148 { \
149 typeof(divisor) __d = divisor; \
150 unsigned long long _tmp = (x) + (__d) / 2; \
151 do_div(_tmp, __d); \
152 _tmp; \
153 } \
154 )
155
156 /*
157 * Multiplies an integer by a fraction, while avoiding unnecessary
158 * overflow or loss of precision.
159 */
160 #define mult_frac(x, numer, denom)( \
161 { \
162 typeof(x) quot = (x) / (denom); \
163 typeof(x) rem = (x) % (denom); \
164 (quot * (numer)) + ((rem * (numer)) / (denom)); \
165 } \
166 )
167
168
169 #define _RET_IP_ (unsigned long)__builtin_return_address(0)
170 #define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; })
171
172 #ifdef CONFIG_LBDAF
173 # include <asm/div64.h>
174 # define sector_div(a, b) do_div(a, b)
175 #else
176 # define sector_div(n, b)( \
177 { \
178 int _res; \
179 _res = (n) % (b); \
180 (n) /= (b); \
181 _res; \
182 } \
183 )
184 #endif
185
186 /**
187 * upper_32_bits - return bits 32-63 of a number
188 * @n: the number we're accessing
189 *
190 * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress
191 * the "right shift count >= width of type" warning when that quantity is
192 * 32-bits.
193 */
194 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
195
196 /**
197 * lower_32_bits - return bits 0-31 of a number
198 * @n: the number we're accessing
199 */
200 #define lower_32_bits(n) ((u32)(n))
201
202 struct completion;
203 struct pt_regs;
204 struct user;
205
206 #ifdef CONFIG_PREEMPT_VOLUNTARY
207 extern int _cond_resched(void);
208 # define might_resched() _cond_resched()
209 #else
210 # define might_resched() do { } while (0)
211 #endif
212
213 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
214 void ___might_sleep(const char *file, int line, int preempt_offset);
215 void __might_sleep(const char *file, int line, int preempt_offset);
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 # define sched_annotate_sleep() (current->task_state_change = 0)
229 #else
230 static inline void ___might_sleep(const char *file, int line,
231 int preempt_offset) { }
232 static inline void __might_sleep(const char *file, int line,
233 int preempt_offset) { }
234 # define might_sleep() do { might_resched(); } while (0)
235 # define sched_annotate_sleep() do { } while (0)
236 #endif
237
238 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
239
240 /**
241 * abs - return absolute value of an argument
242 * @x: the value. If it is unsigned type, it is converted to signed type first.
243 * char is treated as if it was signed (regardless of whether it really is)
244 * but the macro's return type is preserved as char.
245 *
246 * Return: an absolute value of x.
247 */
248 #define abs(x) __abs_choose_expr(x, long long, \
249 __abs_choose_expr(x, long, \
250 __abs_choose_expr(x, int, \
251 __abs_choose_expr(x, short, \
252 __abs_choose_expr(x, char, \
253 __builtin_choose_expr( \
254 __builtin_types_compatible_p(typeof(x), char), \
255 (char)({ signed char __x = (x); __x<0?-__x:__x; }), \
256 ((void)0)))))))
257
258 #define __abs_choose_expr(x, type, other) __builtin_choose_expr( \
259 __builtin_types_compatible_p(typeof(x), signed type) || \
260 __builtin_types_compatible_p(typeof(x), unsigned type), \
261 ({ signed type __x = (x); __x < 0 ? -__x : __x; }), other)
262
263 /**
264 * reciprocal_scale - "scale" a value into range [0, ep_ro)
265 * @val: value
266 * @ep_ro: right open interval endpoint
267 *
268 * Perform a "reciprocal multiplication" in order to "scale" a value into
269 * range [0, @ep_ro), where the upper interval endpoint is right-open.
270 * This is useful, e.g. for accessing a index of an array containing
271 * @ep_ro elements, for example. Think of it as sort of modulus, only that
272 * the result isn't that of modulo. ;) Note that if initial input is a
273 * small value, then result will return 0.
274 *
275 * Return: a result based on @val in interval [0, @ep_ro).
276 */
277 static inline u32 reciprocal_scale(u32 val, u32 ep_ro)
278 {
279 return (u32)(((u64) val * ep_ro) >> 32);
280 }
281
282 #if defined(CONFIG_MMU) && \
283 (defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP))
284 #define might_fault() __might_fault(__FILE__, __LINE__)
285 void __might_fault(const char *file, int line);
286 #else
287 static inline void might_fault(void) { }
288 #endif
289
290 extern struct atomic_notifier_head panic_notifier_list;
291 extern long (*panic_blink)(int state);
292 __printf(1, 2)
293 void panic(const char *fmt, ...) __noreturn __cold;
294 void nmi_panic(struct pt_regs *regs, const char *msg);
295 extern void oops_enter(void);
296 extern void oops_exit(void);
297 void print_oops_end_marker(void);
298 extern int oops_may_print(void);
299 void do_exit(long error_code) __noreturn;
300 void complete_and_exit(struct completion *, long) __noreturn;
301
302 #ifdef CONFIG_ARCH_HAS_REFCOUNT
303 void refcount_error_report(struct pt_regs *regs, const char *err);
304 #else
305 static inline void refcount_error_report(struct pt_regs *regs, const char *err)
306 { }
307 #endif
308
309 /* Internal, do not use. */
310 int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res);
311 int __must_check _kstrtol(const char *s, unsigned int base, long *res);
312
313 int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res);
314 int __must_check kstrtoll(const char *s, unsigned int base, long long *res);
315
316 /**
317 * kstrtoul - convert a string to an unsigned long
318 * @s: The start of the string. The string must be null-terminated, and may also
319 * include a single newline before its terminating null. The first character
320 * may also be a plus sign, but not a minus sign.
321 * @base: The number base to use. The maximum supported base is 16. If base is
322 * given as 0, then the base of the string is automatically detected with the
323 * conventional semantics - If it begins with 0x the number will be parsed as a
324 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be
325 * parsed as an octal number. Otherwise it will be parsed as a decimal.
326 * @res: Where to write the result of the conversion on success.
327 *
328 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
329 * Used as a replacement for the obsolete simple_strtoull. Return code must
330 * be checked.
331 */
332 static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res)
333 {
334 /*
335 * We want to shortcut function call, but
336 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0.
337 */
338 if (sizeof(unsigned long) == sizeof(unsigned long long) &&
339 __alignof__(unsigned long) == __alignof__(unsigned long long))
340 return kstrtoull(s, base, (unsigned long long *)res);
341 else
342 return _kstrtoul(s, base, res);
343 }
344
345 /**
346 * kstrtol - convert a string to a long
347 * @s: The start of the string. The string must be null-terminated, and may also
348 * include a single newline before its terminating null. The first character
349 * may also be a plus sign or a minus sign.
350 * @base: The number base to use. The maximum supported base is 16. If base is
351 * given as 0, then the base of the string is automatically detected with the
352 * conventional semantics - If it begins with 0x the number will be parsed as a
353 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be
354 * parsed as an octal number. Otherwise it will be parsed as a decimal.
355 * @res: Where to write the result of the conversion on success.
356 *
357 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
358 * Used as a replacement for the obsolete simple_strtoull. Return code must
359 * be checked.
360 */
361 static inline int __must_check kstrtol(const char *s, unsigned int base, long *res)
362 {
363 /*
364 * We want to shortcut function call, but
365 * __builtin_types_compatible_p(long, long long) = 0.
366 */
367 if (sizeof(long) == sizeof(long long) &&
368 __alignof__(long) == __alignof__(long long))
369 return kstrtoll(s, base, (long long *)res);
370 else
371 return _kstrtol(s, base, res);
372 }
373
374 int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res);
375 int __must_check kstrtoint(const char *s, unsigned int base, int *res);
376
377 static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res)
378 {
379 return kstrtoull(s, base, res);
380 }
381
382 static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res)
383 {
384 return kstrtoll(s, base, res);
385 }
386
387 static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res)
388 {
389 return kstrtouint(s, base, res);
390 }
391
392 static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res)
393 {
394 return kstrtoint(s, base, res);
395 }
396
397 int __must_check kstrtou16(const char *s, unsigned int base, u16 *res);
398 int __must_check kstrtos16(const char *s, unsigned int base, s16 *res);
399 int __must_check kstrtou8(const char *s, unsigned int base, u8 *res);
400 int __must_check kstrtos8(const char *s, unsigned int base, s8 *res);
401 int __must_check kstrtobool(const char *s, bool *res);
402
403 int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res);
404 int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res);
405 int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res);
406 int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res);
407 int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res);
408 int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res);
409 int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res);
410 int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res);
411 int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res);
412 int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res);
413 int __must_check kstrtobool_from_user(const char __user *s, size_t count, bool *res);
414
415 static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res)
416 {
417 return kstrtoull_from_user(s, count, base, res);
418 }
419
420 static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res)
421 {
422 return kstrtoll_from_user(s, count, base, res);
423 }
424
425 static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res)
426 {
427 return kstrtouint_from_user(s, count, base, res);
428 }
429
430 static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res)
431 {
432 return kstrtoint_from_user(s, count, base, res);
433 }
434
435 /* Obsolete, do not use. Use kstrto<foo> instead */
436
437 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
438 extern long simple_strtol(const char *,char **,unsigned int);
439 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
440 extern long long simple_strtoll(const char *,char **,unsigned int);
441
442 extern int num_to_str(char *buf, int size, unsigned long long num);
443
444 /* lib/printf utilities */
445
446 extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...);
447 extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list);
448 extern __printf(3, 4)
449 int snprintf(char *buf, size_t size, const char *fmt, ...);
450 extern __printf(3, 0)
451 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args);
452 extern __printf(3, 4)
453 int scnprintf(char *buf, size_t size, const char *fmt, ...);
454 extern __printf(3, 0)
455 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args);
456 extern __printf(2, 3) __malloc
457 char *kasprintf(gfp_t gfp, const char *fmt, ...);
458 extern __printf(2, 0) __malloc
459 char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
460 extern __printf(2, 0)
461 const char *kvasprintf_const(gfp_t gfp, const char *fmt, va_list args);
462
463 extern __scanf(2, 3)
464 int sscanf(const char *, const char *, ...);
465 extern __scanf(2, 0)
466 int vsscanf(const char *, const char *, va_list);
467
468 extern int get_option(char **str, int *pint);
469 extern char *get_options(const char *str, int nints, int *ints);
470 extern unsigned long long memparse(const char *ptr, char **retptr);
471 extern bool parse_option_str(const char *str, const char *option);
472 extern char *next_arg(char *args, char **param, char **val);
473
474 extern int core_kernel_text(unsigned long addr);
475 extern int init_kernel_text(unsigned long addr);
476 extern int core_kernel_data(unsigned long addr);
477 extern int __kernel_text_address(unsigned long addr);
478 extern int kernel_text_address(unsigned long addr);
479 extern int func_ptr_is_kernel_text(void *ptr);
480
481 unsigned long int_sqrt(unsigned long);
482
483 extern void bust_spinlocks(int yes);
484 extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */
485 extern int panic_timeout;
486 extern int panic_on_oops;
487 extern int panic_on_unrecovered_nmi;
488 extern int panic_on_io_nmi;
489 extern int panic_on_warn;
490 extern int sysctl_panic_on_rcu_stall;
491 extern int sysctl_panic_on_stackoverflow;
492
493 extern bool crash_kexec_post_notifiers;
494
495 /*
496 * panic_cpu is used for synchronizing panic() and crash_kexec() execution. It
497 * holds a CPU number which is executing panic() currently. A value of
498 * PANIC_CPU_INVALID means no CPU has entered panic() or crash_kexec().
499 */
500 extern atomic_t panic_cpu;
501 #define PANIC_CPU_INVALID -1
502
503 /*
504 * Only to be used by arch init code. If the user over-wrote the default
505 * CONFIG_PANIC_TIMEOUT, honor it.
506 */
507 static inline void set_arch_panic_timeout(int timeout, int arch_default_timeout)
508 {
509 if (panic_timeout == arch_default_timeout)
510 panic_timeout = timeout;
511 }
512 extern const char *print_tainted(void);
513 enum lockdep_ok {
514 LOCKDEP_STILL_OK,
515 LOCKDEP_NOW_UNRELIABLE
516 };
517 extern void add_taint(unsigned flag, enum lockdep_ok);
518 extern int test_taint(unsigned flag);
519 extern unsigned long get_taint(void);
520 extern int root_mountflags;
521
522 extern bool early_boot_irqs_disabled;
523
524 /*
525 * Values used for system_state. Ordering of the states must not be changed
526 * as code checks for <, <=, >, >= STATE.
527 */
528 extern enum system_states {
529 SYSTEM_BOOTING,
530 SYSTEM_SCHEDULING,
531 SYSTEM_RUNNING,
532 SYSTEM_HALT,
533 SYSTEM_POWER_OFF,
534 SYSTEM_RESTART,
535 } system_state;
536
537 #define TAINT_PROPRIETARY_MODULE 0
538 #define TAINT_FORCED_MODULE 1
539 #define TAINT_CPU_OUT_OF_SPEC 2
540 #define TAINT_FORCED_RMMOD 3
541 #define TAINT_MACHINE_CHECK 4
542 #define TAINT_BAD_PAGE 5
543 #define TAINT_USER 6
544 #define TAINT_DIE 7
545 #define TAINT_OVERRIDDEN_ACPI_TABLE 8
546 #define TAINT_WARN 9
547 #define TAINT_CRAP 10
548 #define TAINT_FIRMWARE_WORKAROUND 11
549 #define TAINT_OOT_MODULE 12
550 #define TAINT_UNSIGNED_MODULE 13
551 #define TAINT_SOFTLOCKUP 14
552 #define TAINT_LIVEPATCH 15
553 #define TAINT_AUX 16
554 #define TAINT_FLAGS_COUNT 17
555
556 struct taint_flag {
557 char c_true; /* character printed when tainted */
558 char c_false; /* character printed when not tainted */
559 bool module; /* also show as a per-module taint flag */
560 };
561
562 extern const struct taint_flag taint_flags[TAINT_FLAGS_COUNT];
563
564 extern const char hex_asc[];
565 #define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
566 #define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
567
568 static inline char *hex_byte_pack(char *buf, u8 byte)
569 {
570 *buf++ = hex_asc_hi(byte);
571 *buf++ = hex_asc_lo(byte);
572 return buf;
573 }
574
575 extern const char hex_asc_upper[];
576 #define hex_asc_upper_lo(x) hex_asc_upper[((x) & 0x0f)]
577 #define hex_asc_upper_hi(x) hex_asc_upper[((x) & 0xf0) >> 4]
578
579 static inline char *hex_byte_pack_upper(char *buf, u8 byte)
580 {
581 *buf++ = hex_asc_upper_hi(byte);
582 *buf++ = hex_asc_upper_lo(byte);
583 return buf;
584 }
585
586 extern int hex_to_bin(char ch);
587 extern int __must_check hex2bin(u8 *dst, const char *src, size_t count);
588 extern char *bin2hex(char *dst, const void *src, size_t count);
589
590 bool mac_pton(const char *s, u8 *mac);
591
592 /*
593 * General tracing related utility functions - trace_printk(),
594 * tracing_on/tracing_off and tracing_start()/tracing_stop
595 *
596 * Use tracing_on/tracing_off when you want to quickly turn on or off
597 * tracing. It simply enables or disables the recording of the trace events.
598 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
599 * file, which gives a means for the kernel and userspace to interact.
600 * Place a tracing_off() in the kernel where you want tracing to end.
601 * From user space, examine the trace, and then echo 1 > tracing_on
602 * to continue tracing.
603 *
604 * tracing_stop/tracing_start has slightly more overhead. It is used
605 * by things like suspend to ram where disabling the recording of the
606 * trace is not enough, but tracing must actually stop because things
607 * like calling smp_processor_id() may crash the system.
608 *
609 * Most likely, you want to use tracing_on/tracing_off.
610 */
611
612 enum ftrace_dump_mode {
613 DUMP_NONE,
614 DUMP_ALL,
615 DUMP_ORIG,
616 };
617
618 #ifdef CONFIG_TRACING
619 void tracing_on(void);
620 void tracing_off(void);
621 int tracing_is_on(void);
622 void tracing_snapshot(void);
623 void tracing_snapshot_alloc(void);
624
625 extern void tracing_start(void);
626 extern void tracing_stop(void);
627
628 static inline __printf(1, 2)
629 void ____trace_printk_check_format(const char *fmt, ...)
630 {
631 }
632 #define __trace_printk_check_format(fmt, args...) \
633 do { \
634 if (0) \
635 ____trace_printk_check_format(fmt, ##args); \
636 } while (0)
637
638 /**
639 * trace_printk - printf formatting in the ftrace buffer
640 * @fmt: the printf format for printing
641 *
642 * Note: __trace_printk is an internal function for trace_printk() and
643 * the @ip is passed in via the trace_printk() macro.
644 *
645 * This function allows a kernel developer to debug fast path sections
646 * that printk is not appropriate for. By scattering in various
647 * printk like tracing in the code, a developer can quickly see
648 * where problems are occurring.
649 *
650 * This is intended as a debugging tool for the developer only.
651 * Please refrain from leaving trace_printks scattered around in
652 * your code. (Extra memory is used for special buffers that are
653 * allocated when trace_printk() is used.)
654 *
655 * A little optization trick is done here. If there's only one
656 * argument, there's no need to scan the string for printf formats.
657 * The trace_puts() will suffice. But how can we take advantage of
658 * using trace_puts() when trace_printk() has only one argument?
659 * By stringifying the args and checking the size we can tell
660 * whether or not there are args. __stringify((__VA_ARGS__)) will
661 * turn into "()\0" with a size of 3 when there are no args, anything
662 * else will be bigger. All we need to do is define a string to this,
663 * and then take its size and compare to 3. If it's bigger, use
664 * do_trace_printk() otherwise, optimize it to trace_puts(). Then just
665 * let gcc optimize the rest.
666 */
667
668 #define trace_printk(fmt, ...) \
669 do { \
670 char _______STR[] = __stringify((__VA_ARGS__)); \
671 if (sizeof(_______STR) > 3) \
672 do_trace_printk(fmt, ##__VA_ARGS__); \
673 else \
674 trace_puts(fmt); \
675 } while (0)
676
677 #define do_trace_printk(fmt, args...) \
678 do { \
679 static const char *trace_printk_fmt __used \
680 __attribute__((section("__trace_printk_fmt"))) = \
681 __builtin_constant_p(fmt) ? fmt : NULL; \
682 \
683 __trace_printk_check_format(fmt, ##args); \
684 \
685 if (__builtin_constant_p(fmt)) \
686 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
687 else \
688 __trace_printk(_THIS_IP_, fmt, ##args); \
689 } while (0)
690
691 extern __printf(2, 3)
692 int __trace_bprintk(unsigned long ip, const char *fmt, ...);
693
694 extern __printf(2, 3)
695 int __trace_printk(unsigned long ip, const char *fmt, ...);
696
697 /**
698 * trace_puts - write a string into the ftrace buffer
699 * @str: the string to record
700 *
701 * Note: __trace_bputs is an internal function for trace_puts and
702 * the @ip is passed in via the trace_puts macro.
703 *
704 * This is similar to trace_printk() but is made for those really fast
705 * paths that a developer wants the least amount of "Heisenbug" effects,
706 * where the processing of the print format is still too much.
707 *
708 * This function allows a kernel developer to debug fast path sections
709 * that printk is not appropriate for. By scattering in various
710 * printk like tracing in the code, a developer can quickly see
711 * where problems are occurring.
712 *
713 * This is intended as a debugging tool for the developer only.
714 * Please refrain from leaving trace_puts scattered around in
715 * your code. (Extra memory is used for special buffers that are
716 * allocated when trace_puts() is used.)
717 *
718 * Returns: 0 if nothing was written, positive # if string was.
719 * (1 when __trace_bputs is used, strlen(str) when __trace_puts is used)
720 */
721
722 #define trace_puts(str) ({ \
723 static const char *trace_printk_fmt __used \
724 __attribute__((section("__trace_printk_fmt"))) = \
725 __builtin_constant_p(str) ? str : NULL; \
726 \
727 if (__builtin_constant_p(str)) \
728 __trace_bputs(_THIS_IP_, trace_printk_fmt); \
729 else \
730 __trace_puts(_THIS_IP_, str, strlen(str)); \
731 })
732 extern int __trace_bputs(unsigned long ip, const char *str);
733 extern int __trace_puts(unsigned long ip, const char *str, int size);
734
735 extern void trace_dump_stack(int skip);
736
737 /*
738 * The double __builtin_constant_p is because gcc will give us an error
739 * if we try to allocate the static variable to fmt if it is not a
740 * constant. Even with the outer if statement.
741 */
742 #define ftrace_vprintk(fmt, vargs) \
743 do { \
744 if (__builtin_constant_p(fmt)) { \
745 static const char *trace_printk_fmt __used \
746 __attribute__((section("__trace_printk_fmt"))) = \
747 __builtin_constant_p(fmt) ? fmt : NULL; \
748 \
749 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \
750 } else \
751 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \
752 } while (0)
753
754 extern __printf(2, 0) int
755 __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
756
757 extern __printf(2, 0) int
758 __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
759
760 extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
761 #else
762 static inline void tracing_start(void) { }
763 static inline void tracing_stop(void) { }
764 static inline void trace_dump_stack(int skip) { }
765
766 static inline void tracing_on(void) { }
767 static inline void tracing_off(void) { }
768 static inline int tracing_is_on(void) { return 0; }
769 static inline void tracing_snapshot(void) { }
770 static inline void tracing_snapshot_alloc(void) { }
771
772 static inline __printf(1, 2)
773 int trace_printk(const char *fmt, ...)
774 {
775 return 0;
776 }
777 static __printf(1, 0) inline int
778 ftrace_vprintk(const char *fmt, va_list ap)
779 {
780 return 0;
781 }
782 static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
783 #endif /* CONFIG_TRACING */
784
785 /*
786 * min()/max()/clamp() macros that also do
787 * strict type-checking.. See the
788 * "unnecessary" pointer comparison.
789 */
790 #define __min(t1, t2, min1, min2, x, y) ({ \
791 t1 min1 = (x); \
792 t2 min2 = (y); \
793 (void) (&min1 == &min2); \
794 min1 < min2 ? min1 : min2; })
795
796 /**
797 * min - return minimum of two values of the same or compatible types
798 * @x: first value
799 * @y: second value
800 */
801 #define min(x, y) \
802 __min(typeof(x), typeof(y), \
803 __UNIQUE_ID(min1_), __UNIQUE_ID(min2_), \
804 x, y)
805
806 #define __max(t1, t2, max1, max2, x, y) ({ \
807 t1 max1 = (x); \
808 t2 max2 = (y); \
809 (void) (&max1 == &max2); \
810 max1 > max2 ? max1 : max2; })
811
812 /**
813 * max - return maximum of two values of the same or compatible types
814 * @x: first value
815 * @y: second value
816 */
817 #define max(x, y) \
818 __max(typeof(x), typeof(y), \
819 __UNIQUE_ID(max1_), __UNIQUE_ID(max2_), \
820 x, y)
821
822 /**
823 * min3 - return minimum of three values
824 * @x: first value
825 * @y: second value
826 * @z: third value
827 */
828 #define min3(x, y, z) min((typeof(x))min(x, y), z)
829
830 /**
831 * max3 - return maximum of three values
832 * @x: first value
833 * @y: second value
834 * @z: third value
835 */
836 #define max3(x, y, z) max((typeof(x))max(x, y), z)
837
838 /**
839 * min_not_zero - return the minimum that is _not_ zero, unless both are zero
840 * @x: value1
841 * @y: value2
842 */
843 #define min_not_zero(x, y) ({ \
844 typeof(x) __x = (x); \
845 typeof(y) __y = (y); \
846 __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); })
847
848 /**
849 * clamp - return a value clamped to a given range with strict typechecking
850 * @val: current value
851 * @lo: lowest allowable value
852 * @hi: highest allowable value
853 *
854 * This macro does strict typechecking of @lo/@hi to make sure they are of the
855 * same type as @val. See the unnecessary pointer comparisons.
856 */
857 #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi)
858
859 /*
860 * ..and if you can't take the strict
861 * types, you can specify one yourself.
862 *
863 * Or not use min/max/clamp at all, of course.
864 */
865
866 /**
867 * min_t - return minimum of two values, using the specified type
868 * @type: data type to use
869 * @x: first value
870 * @y: second value
871 */
872 #define min_t(type, x, y) \
873 __min(type, type, \
874 __UNIQUE_ID(min1_), __UNIQUE_ID(min2_), \
875 x, y)
876
877 /**
878 * max_t - return maximum of two values, using the specified type
879 * @type: data type to use
880 * @x: first value
881 * @y: second value
882 */
883 #define max_t(type, x, y) \
884 __max(type, type, \
885 __UNIQUE_ID(min1_), __UNIQUE_ID(min2_), \
886 x, y)
887
888 /**
889 * clamp_t - return a value clamped to a given range using a given type
890 * @type: the type of variable to use
891 * @val: current value
892 * @lo: minimum allowable value
893 * @hi: maximum allowable value
894 *
895 * This macro does no typechecking and uses temporary variables of type
896 * @type to make all the comparisons.
897 */
898 #define clamp_t(type, val, lo, hi) min_t(type, max_t(type, val, lo), hi)
899
900 /**
901 * clamp_val - return a value clamped to a given range using val's type
902 * @val: current value
903 * @lo: minimum allowable value
904 * @hi: maximum allowable value
905 *
906 * This macro does no typechecking and uses temporary variables of whatever
907 * type the input argument @val is. This is useful when @val is an unsigned
908 * type and @lo and @hi are literals that will otherwise be assigned a signed
909 * integer type.
910 */
911 #define clamp_val(val, lo, hi) clamp_t(typeof(val), val, lo, hi)
912
913
914 /**
915 * swap - swap values of @a and @b
916 * @a: first value
917 * @b: second value
918 */
919 #define swap(a, b) \
920 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
921
922 /**
923 * container_of - cast a member of a structure out to the containing structure
924 * @ptr: the pointer to the member.
925 * @type: the type of the container struct this is embedded in.
926 * @member: the name of the member within the struct.
927 *
928 */
929 #define container_of(ptr, type, member) ({ \
930 void *__mptr = (void *)(ptr); \
931 BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \
932 !__same_type(*(ptr), void), \
933 "pointer type mismatch in container_of()"); \
934 ((type *)(__mptr - offsetof(type, member))); })
935
936 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
937 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
938 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
939 #endif
940
941 /* Permissions on a sysfs file: you didn't miss the 0 prefix did you? */
942 #define VERIFY_OCTAL_PERMISSIONS(perms) \
943 (BUILD_BUG_ON_ZERO((perms) < 0) + \
944 BUILD_BUG_ON_ZERO((perms) > 0777) + \
945 /* USER_READABLE >= GROUP_READABLE >= OTHER_READABLE */ \
946 BUILD_BUG_ON_ZERO((((perms) >> 6) & 4) < (((perms) >> 3) & 4)) + \
947 BUILD_BUG_ON_ZERO((((perms) >> 3) & 4) < ((perms) & 4)) + \
948 /* USER_WRITABLE >= GROUP_WRITABLE */ \
949 BUILD_BUG_ON_ZERO((((perms) >> 6) & 2) < (((perms) >> 3) & 2)) + \
950 /* OTHER_WRITABLE? Generally considered a bad idea. */ \
951 BUILD_BUG_ON_ZERO((perms) & 2) + \
952 (perms))
953 #endif
954
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