1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_KERNEL_H
3 #define _LINUX_KERNEL_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>
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)
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))
46 #define STACK_MAGIC 0xdeadbeef
49 * REPEAT_BYTE - repeat the value @x multiple times as an unsigned long value
52 * NOTE: @x is not checked for > 0xff; larger values produce odd results.
54 #define REPEAT_BYTE(x) ((~0ul / 0xff) * (x))
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)
63 /* generic data direction definitions */
68 * ARRAY_SIZE - get the number of elements in array @arr
69 * @arr: array to be sized
71 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
73 #define u64_to_user_ptr(x) ( \
75 typecheck(u64, (x)); \
76 (void __user *)(uintptr_t)(x); \
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.
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))
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.
97 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
99 #define DIV_ROUND_UP __KERNEL_DIV_ROUND_UP
101 #define DIV_ROUND_DOWN_ULL(ll, d) \
102 ({ unsigned long long _tmp = (ll); do_div(_tmp, d); _tmp; })
104 #define DIV_ROUND_UP_ULL(ll, d) \
105 DIV_ROUND_DOWN_ULL((unsigned long long)(ll) + (d) - 1, (d))
107 #if BITS_PER_LONG == 32
108 # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d)
110 # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP(ll,d)
113 /* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */
114 #define roundup(x, y) ( \
116 const typeof(y) __y = y; \
117 (((x) + (__y - 1)) / __y) * __y; \
120 #define rounddown(x, y) ( \
122 typeof(x) __x = (x); \
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.
133 #define DIV_ROUND_CLOSEST(x, divisor)( \
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)); \
145 * Same as above but for u64 dividends. divisor must be a 32-bit
148 #define DIV_ROUND_CLOSEST_ULL(x, divisor)( \
150 typeof(divisor) __d = divisor; \
151 unsigned long long _tmp = (x) + (__d) / 2; \
158 * Multiplies an integer by a fraction, while avoiding unnecessary
159 * overflow or loss of precision.
161 #define mult_frac(x, numer, denom)( \
163 typeof(x) quot = (x) / (denom); \
164 typeof(x) rem = (x) % (denom); \
165 (quot * (numer)) + ((rem * (numer)) / (denom)); \
170 #define _RET_IP_ (unsigned long)__builtin_return_address(0)
171 #define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; })
174 # include <asm/div64.h>
175 # define sector_div(a, b) do_div(a, b)
177 # define sector_div(n, b)( \
188 * upper_32_bits - return bits 32-63 of a number
189 * @n: the number we're accessing
191 * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress
192 * the "right shift count >= width of type" warning when that quantity is
195 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
198 * lower_32_bits - return bits 0-31 of a number
199 * @n: the number we're accessing
201 #define lower_32_bits(n) ((u32)(n))
207 #ifdef CONFIG_PREEMPT_VOLUNTARY
208 extern int _cond_resched(void);
209 # define might_resched() _cond_resched()
211 # define might_resched() do { } while (0)
214 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
215 void ___might_sleep(const char *file
, int line
, int preempt_offset
);
216 void __might_sleep(const char *file
, int line
, int preempt_offset
);
218 * might_sleep - annotation for functions that can sleep
220 * this macro will print a stack trace if it is executed in an atomic
221 * context (spinlock, irq-handler, ...).
223 * This is a useful debugging help to be able to catch problems early and not
224 * be bitten later when the calling function happens to sleep when it is not
227 # define might_sleep() \
228 do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
229 # define sched_annotate_sleep() (current->task_state_change = 0)
231 static inline void ___might_sleep(const char *file
, int line
,
232 int preempt_offset
) { }
233 static inline void __might_sleep(const char *file
, int line
,
234 int preempt_offset
) { }
235 # define might_sleep() do { might_resched(); } while (0)
236 # define sched_annotate_sleep() do { } while (0)
239 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
242 * abs - return absolute value of an argument
243 * @x: the value. If it is unsigned type, it is converted to signed type first.
244 * char is treated as if it was signed (regardless of whether it really is)
245 * but the macro's return type is preserved as char.
247 * Return: an absolute value of x.
249 #define abs(x) __abs_choose_expr(x, long long, \
250 __abs_choose_expr(x, long, \
251 __abs_choose_expr(x, int, \
252 __abs_choose_expr(x, short, \
253 __abs_choose_expr(x, char, \
254 __builtin_choose_expr( \
255 __builtin_types_compatible_p(typeof(x), char), \
256 (char)({ signed char __x = (x); __x<0?-__x:__x; }), \
259 #define __abs_choose_expr(x, type, other) __builtin_choose_expr( \
260 __builtin_types_compatible_p(typeof(x), signed type) || \
261 __builtin_types_compatible_p(typeof(x), unsigned type), \
262 ({ signed type __x = (x); __x < 0 ? -__x : __x; }), other)
265 * reciprocal_scale - "scale" a value into range [0, ep_ro)
267 * @ep_ro: right open interval endpoint
269 * Perform a "reciprocal multiplication" in order to "scale" a value into
270 * range [0, @ep_ro), where the upper interval endpoint is right-open.
271 * This is useful, e.g. for accessing a index of an array containing
272 * @ep_ro elements, for example. Think of it as sort of modulus, only that
273 * the result isn't that of modulo. ;) Note that if initial input is a
274 * small value, then result will return 0.
276 * Return: a result based on @val in interval [0, @ep_ro).
278 static inline u32
reciprocal_scale(u32 val
, u32 ep_ro
)
280 return (u32
)(((u64
) val
* ep_ro
) >> 32);
283 #if defined(CONFIG_MMU) && \
284 (defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP))
285 #define might_fault() __might_fault(__FILE__, __LINE__)
286 void __might_fault(const char *file
, int line
);
288 static inline void might_fault(void) { }
291 extern struct atomic_notifier_head panic_notifier_list
;
292 extern long (*panic_blink
)(int state
);
294 void panic(const char *fmt
, ...) __noreturn __cold
;
295 void nmi_panic(struct pt_regs
*regs
, const char *msg
);
296 extern void oops_enter(void);
297 extern void oops_exit(void);
298 void print_oops_end_marker(void);
299 extern int oops_may_print(void);
300 void do_exit(long error_code
) __noreturn
;
301 void complete_and_exit(struct completion
*, long) __noreturn
;
303 #ifdef CONFIG_ARCH_HAS_REFCOUNT
304 void refcount_error_report(struct pt_regs
*regs
, const char *err
);
306 static inline void refcount_error_report(struct pt_regs
*regs
, const char *err
)
310 #ifdef CONFIG_LOCK_DOWN_KERNEL
311 extern bool __kernel_is_locked_down(const char *what
, bool first
);
313 static inline bool __kernel_is_locked_down(const char *what
, bool first
)
319 #define kernel_is_locked_down(what) \
321 static bool message_given; \
322 bool locked_down = __kernel_is_locked_down(what, !message_given); \
323 message_given = true; \
327 /* Internal, do not use. */
328 int __must_check
_kstrtoul(const char *s
, unsigned int base
, unsigned long *res
);
329 int __must_check
_kstrtol(const char *s
, unsigned int base
, long *res
);
331 int __must_check
kstrtoull(const char *s
, unsigned int base
, unsigned long long *res
);
332 int __must_check
kstrtoll(const char *s
, unsigned int base
, long long *res
);
335 * kstrtoul - convert a string to an unsigned long
336 * @s: The start of the string. The string must be null-terminated, and may also
337 * include a single newline before its terminating null. The first character
338 * may also be a plus sign, but not a minus sign.
339 * @base: The number base to use. The maximum supported base is 16. If base is
340 * given as 0, then the base of the string is automatically detected with the
341 * conventional semantics - If it begins with 0x the number will be parsed as a
342 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be
343 * parsed as an octal number. Otherwise it will be parsed as a decimal.
344 * @res: Where to write the result of the conversion on success.
346 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
347 * Used as a replacement for the obsolete simple_strtoull. Return code must
350 static inline int __must_check
kstrtoul(const char *s
, unsigned int base
, unsigned long *res
)
353 * We want to shortcut function call, but
354 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0.
356 if (sizeof(unsigned long) == sizeof(unsigned long long) &&
357 __alignof__(unsigned long) == __alignof__(unsigned long long))
358 return kstrtoull(s
, base
, (unsigned long long *)res
);
360 return _kstrtoul(s
, base
, res
);
364 * kstrtol - convert a string to a long
365 * @s: The start of the string. The string must be null-terminated, and may also
366 * include a single newline before its terminating null. The first character
367 * may also be a plus sign or a minus sign.
368 * @base: The number base to use. The maximum supported base is 16. If base is
369 * given as 0, then the base of the string is automatically detected with the
370 * conventional semantics - If it begins with 0x the number will be parsed as a
371 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be
372 * parsed as an octal number. Otherwise it will be parsed as a decimal.
373 * @res: Where to write the result of the conversion on success.
375 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
376 * Used as a replacement for the obsolete simple_strtoull. Return code must
379 static inline int __must_check
kstrtol(const char *s
, unsigned int base
, long *res
)
382 * We want to shortcut function call, but
383 * __builtin_types_compatible_p(long, long long) = 0.
385 if (sizeof(long) == sizeof(long long) &&
386 __alignof__(long) == __alignof__(long long))
387 return kstrtoll(s
, base
, (long long *)res
);
389 return _kstrtol(s
, base
, res
);
392 int __must_check
kstrtouint(const char *s
, unsigned int base
, unsigned int *res
);
393 int __must_check
kstrtoint(const char *s
, unsigned int base
, int *res
);
395 static inline int __must_check
kstrtou64(const char *s
, unsigned int base
, u64
*res
)
397 return kstrtoull(s
, base
, res
);
400 static inline int __must_check
kstrtos64(const char *s
, unsigned int base
, s64
*res
)
402 return kstrtoll(s
, base
, res
);
405 static inline int __must_check
kstrtou32(const char *s
, unsigned int base
, u32
*res
)
407 return kstrtouint(s
, base
, res
);
410 static inline int __must_check
kstrtos32(const char *s
, unsigned int base
, s32
*res
)
412 return kstrtoint(s
, base
, res
);
415 int __must_check
kstrtou16(const char *s
, unsigned int base
, u16
*res
);
416 int __must_check
kstrtos16(const char *s
, unsigned int base
, s16
*res
);
417 int __must_check
kstrtou8(const char *s
, unsigned int base
, u8
*res
);
418 int __must_check
kstrtos8(const char *s
, unsigned int base
, s8
*res
);
419 int __must_check
kstrtobool(const char *s
, bool *res
);
421 int __must_check
kstrtoull_from_user(const char __user
*s
, size_t count
, unsigned int base
, unsigned long long *res
);
422 int __must_check
kstrtoll_from_user(const char __user
*s
, size_t count
, unsigned int base
, long long *res
);
423 int __must_check
kstrtoul_from_user(const char __user
*s
, size_t count
, unsigned int base
, unsigned long *res
);
424 int __must_check
kstrtol_from_user(const char __user
*s
, size_t count
, unsigned int base
, long *res
);
425 int __must_check
kstrtouint_from_user(const char __user
*s
, size_t count
, unsigned int base
, unsigned int *res
);
426 int __must_check
kstrtoint_from_user(const char __user
*s
, size_t count
, unsigned int base
, int *res
);
427 int __must_check
kstrtou16_from_user(const char __user
*s
, size_t count
, unsigned int base
, u16
*res
);
428 int __must_check
kstrtos16_from_user(const char __user
*s
, size_t count
, unsigned int base
, s16
*res
);
429 int __must_check
kstrtou8_from_user(const char __user
*s
, size_t count
, unsigned int base
, u8
*res
);
430 int __must_check
kstrtos8_from_user(const char __user
*s
, size_t count
, unsigned int base
, s8
*res
);
431 int __must_check
kstrtobool_from_user(const char __user
*s
, size_t count
, bool *res
);
433 static inline int __must_check
kstrtou64_from_user(const char __user
*s
, size_t count
, unsigned int base
, u64
*res
)
435 return kstrtoull_from_user(s
, count
, base
, res
);
438 static inline int __must_check
kstrtos64_from_user(const char __user
*s
, size_t count
, unsigned int base
, s64
*res
)
440 return kstrtoll_from_user(s
, count
, base
, res
);
443 static inline int __must_check
kstrtou32_from_user(const char __user
*s
, size_t count
, unsigned int base
, u32
*res
)
445 return kstrtouint_from_user(s
, count
, base
, res
);
448 static inline int __must_check
kstrtos32_from_user(const char __user
*s
, size_t count
, unsigned int base
, s32
*res
)
450 return kstrtoint_from_user(s
, count
, base
, res
);
453 /* Obsolete, do not use. Use kstrto<foo> instead */
455 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
456 extern long simple_strtol(const char *,char **,unsigned int);
457 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
458 extern long long simple_strtoll(const char *,char **,unsigned int);
460 extern int num_to_str(char *buf
, int size
, unsigned long long num
);
462 /* lib/printf utilities */
464 extern __printf(2, 3) int sprintf(char *buf
, const char * fmt
, ...);
465 extern __printf(2, 0) int vsprintf(char *buf
, const char *, va_list);
466 extern __printf(3, 4)
467 int snprintf(char *buf
, size_t size
, const char *fmt
, ...);
468 extern __printf(3, 0)
469 int vsnprintf(char *buf
, size_t size
, const char *fmt
, va_list args
);
470 extern __printf(3, 4)
471 int scnprintf(char *buf
, size_t size
, const char *fmt
, ...);
472 extern __printf(3, 0)
473 int vscnprintf(char *buf
, size_t size
, const char *fmt
, va_list args
);
474 extern __printf(2, 3) __malloc
475 char *kasprintf(gfp_t gfp
, const char *fmt
, ...);
476 extern __printf(2, 0) __malloc
477 char *kvasprintf(gfp_t gfp
, const char *fmt
, va_list args
);
478 extern __printf(2, 0)
479 const char *kvasprintf_const(gfp_t gfp
, const char *fmt
, va_list args
);
482 int sscanf(const char *, const char *, ...);
484 int vsscanf(const char *, const char *, va_list);
486 extern int get_option(char **str
, int *pint
);
487 extern char *get_options(const char *str
, int nints
, int *ints
);
488 extern unsigned long long memparse(const char *ptr
, char **retptr
);
489 extern bool parse_option_str(const char *str
, const char *option
);
490 extern char *next_arg(char *args
, char **param
, char **val
);
492 extern int core_kernel_text(unsigned long addr
);
493 extern int core_kernel_data(unsigned long addr
);
494 extern int __kernel_text_address(unsigned long addr
);
495 extern int kernel_text_address(unsigned long addr
);
496 extern int func_ptr_is_kernel_text(void *ptr
);
498 unsigned long int_sqrt(unsigned long);
500 extern void bust_spinlocks(int yes
);
501 extern int oops_in_progress
; /* If set, an oops, panic(), BUG() or die() is in progress */
502 extern int panic_timeout
;
503 extern int panic_on_oops
;
504 extern int panic_on_unrecovered_nmi
;
505 extern int panic_on_io_nmi
;
506 extern int panic_on_warn
;
507 extern int sysctl_panic_on_rcu_stall
;
508 extern int sysctl_panic_on_stackoverflow
;
510 extern bool crash_kexec_post_notifiers
;
513 * panic_cpu is used for synchronizing panic() and crash_kexec() execution. It
514 * holds a CPU number which is executing panic() currently. A value of
515 * PANIC_CPU_INVALID means no CPU has entered panic() or crash_kexec().
517 extern atomic_t panic_cpu
;
518 #define PANIC_CPU_INVALID -1
521 * Only to be used by arch init code. If the user over-wrote the default
522 * CONFIG_PANIC_TIMEOUT, honor it.
524 static inline void set_arch_panic_timeout(int timeout
, int arch_default_timeout
)
526 if (panic_timeout
== arch_default_timeout
)
527 panic_timeout
= timeout
;
529 extern const char *print_tainted(void);
532 LOCKDEP_NOW_UNRELIABLE
534 extern void add_taint(unsigned flag
, enum lockdep_ok
);
535 extern int test_taint(unsigned flag
);
536 extern unsigned long get_taint(void);
537 extern int root_mountflags
;
539 extern bool early_boot_irqs_disabled
;
542 * Values used for system_state. Ordering of the states must not be changed
543 * as code checks for <, <=, >, >= STATE.
545 extern enum system_states
{
554 #define TAINT_PROPRIETARY_MODULE 0
555 #define TAINT_FORCED_MODULE 1
556 #define TAINT_CPU_OUT_OF_SPEC 2
557 #define TAINT_FORCED_RMMOD 3
558 #define TAINT_MACHINE_CHECK 4
559 #define TAINT_BAD_PAGE 5
562 #define TAINT_OVERRIDDEN_ACPI_TABLE 8
564 #define TAINT_CRAP 10
565 #define TAINT_FIRMWARE_WORKAROUND 11
566 #define TAINT_OOT_MODULE 12
567 #define TAINT_UNSIGNED_MODULE 13
568 #define TAINT_SOFTLOCKUP 14
569 #define TAINT_LIVEPATCH 15
571 #define TAINT_FLAGS_COUNT 17
574 char c_true
; /* character printed when tainted */
575 char c_false
; /* character printed when not tainted */
576 bool module
; /* also show as a per-module taint flag */
579 extern const struct taint_flag taint_flags
[TAINT_FLAGS_COUNT
];
581 extern const char hex_asc
[];
582 #define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
583 #define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
585 static inline char *hex_byte_pack(char *buf
, u8 byte
)
587 *buf
++ = hex_asc_hi(byte
);
588 *buf
++ = hex_asc_lo(byte
);
592 extern const char hex_asc_upper
[];
593 #define hex_asc_upper_lo(x) hex_asc_upper[((x) & 0x0f)]
594 #define hex_asc_upper_hi(x) hex_asc_upper[((x) & 0xf0) >> 4]
596 static inline char *hex_byte_pack_upper(char *buf
, u8 byte
)
598 *buf
++ = hex_asc_upper_hi(byte
);
599 *buf
++ = hex_asc_upper_lo(byte
);
603 extern int hex_to_bin(char ch
);
604 extern int __must_check
hex2bin(u8
*dst
, const char *src
, size_t count
);
605 extern char *bin2hex(char *dst
, const void *src
, size_t count
);
607 bool mac_pton(const char *s
, u8
*mac
);
610 * General tracing related utility functions - trace_printk(),
611 * tracing_on/tracing_off and tracing_start()/tracing_stop
613 * Use tracing_on/tracing_off when you want to quickly turn on or off
614 * tracing. It simply enables or disables the recording of the trace events.
615 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
616 * file, which gives a means for the kernel and userspace to interact.
617 * Place a tracing_off() in the kernel where you want tracing to end.
618 * From user space, examine the trace, and then echo 1 > tracing_on
619 * to continue tracing.
621 * tracing_stop/tracing_start has slightly more overhead. It is used
622 * by things like suspend to ram where disabling the recording of the
623 * trace is not enough, but tracing must actually stop because things
624 * like calling smp_processor_id() may crash the system.
626 * Most likely, you want to use tracing_on/tracing_off.
629 enum ftrace_dump_mode
{
635 #ifdef CONFIG_TRACING
636 void tracing_on(void);
637 void tracing_off(void);
638 int tracing_is_on(void);
639 void tracing_snapshot(void);
640 void tracing_snapshot_alloc(void);
642 extern void tracing_start(void);
643 extern void tracing_stop(void);
645 static inline __printf(1, 2)
646 void ____trace_printk_check_format(const char *fmt
, ...)
649 #define __trace_printk_check_format(fmt, args...) \
652 ____trace_printk_check_format(fmt, ##args); \
656 * trace_printk - printf formatting in the ftrace buffer
657 * @fmt: the printf format for printing
659 * Note: __trace_printk is an internal function for trace_printk() and
660 * the @ip is passed in via the trace_printk() macro.
662 * This function allows a kernel developer to debug fast path sections
663 * that printk is not appropriate for. By scattering in various
664 * printk like tracing in the code, a developer can quickly see
665 * where problems are occurring.
667 * This is intended as a debugging tool for the developer only.
668 * Please refrain from leaving trace_printks scattered around in
669 * your code. (Extra memory is used for special buffers that are
670 * allocated when trace_printk() is used.)
672 * A little optization trick is done here. If there's only one
673 * argument, there's no need to scan the string for printf formats.
674 * The trace_puts() will suffice. But how can we take advantage of
675 * using trace_puts() when trace_printk() has only one argument?
676 * By stringifying the args and checking the size we can tell
677 * whether or not there are args. __stringify((__VA_ARGS__)) will
678 * turn into "()\0" with a size of 3 when there are no args, anything
679 * else will be bigger. All we need to do is define a string to this,
680 * and then take its size and compare to 3. If it's bigger, use
681 * do_trace_printk() otherwise, optimize it to trace_puts(). Then just
682 * let gcc optimize the rest.
685 #define trace_printk(fmt, ...) \
687 char _______STR[] = __stringify((__VA_ARGS__)); \
688 if (sizeof(_______STR) > 3) \
689 do_trace_printk(fmt, ##__VA_ARGS__); \
694 #define do_trace_printk(fmt, args...) \
696 static const char *trace_printk_fmt __used \
697 __attribute__((section("__trace_printk_fmt"))) = \
698 __builtin_constant_p(fmt) ? fmt : NULL; \
700 __trace_printk_check_format(fmt, ##args); \
702 if (__builtin_constant_p(fmt)) \
703 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
705 __trace_printk(_THIS_IP_, fmt, ##args); \
708 extern __printf(2, 3)
709 int __trace_bprintk(unsigned long ip
, const char *fmt
, ...);
711 extern __printf(2, 3)
712 int __trace_printk(unsigned long ip
, const char *fmt
, ...);
715 * trace_puts - write a string into the ftrace buffer
716 * @str: the string to record
718 * Note: __trace_bputs is an internal function for trace_puts and
719 * the @ip is passed in via the trace_puts macro.
721 * This is similar to trace_printk() but is made for those really fast
722 * paths that a developer wants the least amount of "Heisenbug" effects,
723 * where the processing of the print format is still too much.
725 * This function allows a kernel developer to debug fast path sections
726 * that printk is not appropriate for. By scattering in various
727 * printk like tracing in the code, a developer can quickly see
728 * where problems are occurring.
730 * This is intended as a debugging tool for the developer only.
731 * Please refrain from leaving trace_puts scattered around in
732 * your code. (Extra memory is used for special buffers that are
733 * allocated when trace_puts() is used.)
735 * Returns: 0 if nothing was written, positive # if string was.
736 * (1 when __trace_bputs is used, strlen(str) when __trace_puts is used)
739 #define trace_puts(str) ({ \
740 static const char *trace_printk_fmt __used \
741 __attribute__((section("__trace_printk_fmt"))) = \
742 __builtin_constant_p(str) ? str : NULL; \
744 if (__builtin_constant_p(str)) \
745 __trace_bputs(_THIS_IP_, trace_printk_fmt); \
747 __trace_puts(_THIS_IP_, str, strlen(str)); \
749 extern int __trace_bputs(unsigned long ip
, const char *str
);
750 extern int __trace_puts(unsigned long ip
, const char *str
, int size
);
752 extern void trace_dump_stack(int skip
);
755 * The double __builtin_constant_p is because gcc will give us an error
756 * if we try to allocate the static variable to fmt if it is not a
757 * constant. Even with the outer if statement.
759 #define ftrace_vprintk(fmt, vargs) \
761 if (__builtin_constant_p(fmt)) { \
762 static const char *trace_printk_fmt __used \
763 __attribute__((section("__trace_printk_fmt"))) = \
764 __builtin_constant_p(fmt) ? fmt : NULL; \
766 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \
768 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \
771 extern __printf(2, 0) int
772 __ftrace_vbprintk(unsigned long ip
, const char *fmt
, va_list ap
);
774 extern __printf(2, 0) int
775 __ftrace_vprintk(unsigned long ip
, const char *fmt
, va_list ap
);
777 extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode
);
779 static inline void tracing_start(void) { }
780 static inline void tracing_stop(void) { }
781 static inline void trace_dump_stack(int skip
) { }
783 static inline void tracing_on(void) { }
784 static inline void tracing_off(void) { }
785 static inline int tracing_is_on(void) { return 0; }
786 static inline void tracing_snapshot(void) { }
787 static inline void tracing_snapshot_alloc(void) { }
789 static inline __printf(1, 2)
790 int trace_printk(const char *fmt
, ...)
794 static __printf(1, 0) inline int
795 ftrace_vprintk(const char *fmt
, va_list ap
)
799 static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode
) { }
800 #endif /* CONFIG_TRACING */
803 * min()/max()/clamp() macros that also do
804 * strict type-checking.. See the
805 * "unnecessary" pointer comparison.
807 #define __min(t1, t2, min1, min2, x, y) ({ \
810 (void) (&min1 == &min2); \
811 min1 < min2 ? min1 : min2; })
814 * min - return minimum of two values of the same or compatible types
819 __min(typeof(x), typeof(y), \
820 __UNIQUE_ID(min1_), __UNIQUE_ID(min2_), \
823 #define __max(t1, t2, max1, max2, x, y) ({ \
826 (void) (&max1 == &max2); \
827 max1 > max2 ? max1 : max2; })
830 * max - return maximum of two values of the same or compatible types
835 __max(typeof(x), typeof(y), \
836 __UNIQUE_ID(max1_), __UNIQUE_ID(max2_), \
840 * min3 - return minimum of three values
845 #define min3(x, y, z) min((typeof(x))min(x, y), z)
848 * max3 - return maximum of three values
853 #define max3(x, y, z) max((typeof(x))max(x, y), z)
856 * min_not_zero - return the minimum that is _not_ zero, unless both are zero
860 #define min_not_zero(x, y) ({ \
861 typeof(x) __x = (x); \
862 typeof(y) __y = (y); \
863 __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); })
866 * clamp - return a value clamped to a given range with strict typechecking
867 * @val: current value
868 * @lo: lowest allowable value
869 * @hi: highest allowable value
871 * This macro does strict typechecking of @lo/@hi to make sure they are of the
872 * same type as @val. See the unnecessary pointer comparisons.
874 #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi)
877 * ..and if you can't take the strict
878 * types, you can specify one yourself.
880 * Or not use min/max/clamp at all, of course.
884 * min_t - return minimum of two values, using the specified type
885 * @type: data type to use
889 #define min_t(type, x, y) \
891 __UNIQUE_ID(min1_), __UNIQUE_ID(min2_), \
895 * max_t - return maximum of two values, using the specified type
896 * @type: data type to use
900 #define max_t(type, x, y) \
902 __UNIQUE_ID(min1_), __UNIQUE_ID(min2_), \
906 * clamp_t - return a value clamped to a given range using a given type
907 * @type: the type of variable to use
908 * @val: current value
909 * @lo: minimum allowable value
910 * @hi: maximum allowable value
912 * This macro does no typechecking and uses temporary variables of type
913 * @type to make all the comparisons.
915 #define clamp_t(type, val, lo, hi) min_t(type, max_t(type, val, lo), hi)
918 * clamp_val - return a value clamped to a given range using val's type
919 * @val: current value
920 * @lo: minimum allowable value
921 * @hi: maximum allowable value
923 * This macro does no typechecking and uses temporary variables of whatever
924 * type the input argument @val is. This is useful when @val is an unsigned
925 * type and @lo and @hi are literals that will otherwise be assigned a signed
928 #define clamp_val(val, lo, hi) clamp_t(typeof(val), val, lo, hi)
932 * swap - swap values of @a and @b
937 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
940 * container_of - cast a member of a structure out to the containing structure
941 * @ptr: the pointer to the member.
942 * @type: the type of the container struct this is embedded in.
943 * @member: the name of the member within the struct.
946 #define container_of(ptr, type, member) ({ \
947 void *__mptr = (void *)(ptr); \
948 BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \
949 !__same_type(*(ptr), void), \
950 "pointer type mismatch in container_of()"); \
951 ((type *)(__mptr - offsetof(type, member))); })
953 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
954 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
955 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
958 /* Permissions on a sysfs file: you didn't miss the 0 prefix did you? */
959 #define VERIFY_OCTAL_PERMISSIONS(perms) \
960 (BUILD_BUG_ON_ZERO((perms) < 0) + \
961 BUILD_BUG_ON_ZERO((perms) > 0777) + \
962 /* USER_READABLE >= GROUP_READABLE >= OTHER_READABLE */ \
963 BUILD_BUG_ON_ZERO((((perms) >> 6) & 4) < (((perms) >> 3) & 4)) + \
964 BUILD_BUG_ON_ZERO((((perms) >> 3) & 4) < ((perms) & 4)) + \
965 /* USER_WRITABLE >= GROUP_WRITABLE */ \
966 BUILD_BUG_ON_ZERO((((perms) >> 6) & 2) < (((perms) >> 3) & 2)) + \
967 /* OTHER_WRITABLE? Generally considered a bad idea. */ \
968 BUILD_BUG_ON_ZERO((perms) & 2) + \