projects/linux·blob v5.8 · refs

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