xref: /linux-6.15/include/linux/kernel.h (revision c145211d)
1 #ifndef _LINUX_KERNEL_H
2 #define _LINUX_KERNEL_H
3 
4 /*
5  * 'kernel.h' contains some often-used function prototypes etc
6  */
7 
8 #ifdef __KERNEL__
9 
10 #include <stdarg.h>
11 #include <linux/linkage.h>
12 #include <linux/stddef.h>
13 #include <linux/types.h>
14 #include <linux/compiler.h>
15 #include <linux/bitops.h>
16 #include <linux/log2.h>
17 #include <linux/typecheck.h>
18 #include <linux/dynamic_debug.h>
19 #include <asm/byteorder.h>
20 #include <asm/bug.h>
21 
22 extern const char linux_banner[];
23 extern const char linux_proc_banner[];
24 
25 #define USHORT_MAX	((u16)(~0U))
26 #define SHORT_MAX	((s16)(USHORT_MAX>>1))
27 #define SHORT_MIN	(-SHORT_MAX - 1)
28 #define INT_MAX		((int)(~0U>>1))
29 #define INT_MIN		(-INT_MAX - 1)
30 #define UINT_MAX	(~0U)
31 #define LONG_MAX	((long)(~0UL>>1))
32 #define LONG_MIN	(-LONG_MAX - 1)
33 #define ULONG_MAX	(~0UL)
34 #define LLONG_MAX	((long long)(~0ULL>>1))
35 #define LLONG_MIN	(-LLONG_MAX - 1)
36 #define ULLONG_MAX	(~0ULL)
37 
38 #define STACK_MAGIC	0xdeadbeef
39 
40 #define ALIGN(x,a)		__ALIGN_MASK(x,(typeof(x))(a)-1)
41 #define __ALIGN_MASK(x,mask)	(((x)+(mask))&~(mask))
42 #define PTR_ALIGN(p, a)		((typeof(p))ALIGN((unsigned long)(p), (a)))
43 #define IS_ALIGNED(x, a)		(((x) & ((typeof(x))(a) - 1)) == 0)
44 
45 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
46 
47 /*
48  * This looks more complex than it should be. But we need to
49  * get the type for the ~ right in round_down (it needs to be
50  * as wide as the result!), and we want to evaluate the macro
51  * arguments just once each.
52  */
53 #define __round_mask(x, y) ((__typeof__(x))((y)-1))
54 #define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
55 #define round_down(x, y) ((x) & ~__round_mask(x, y))
56 
57 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
58 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
59 #define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
60 #define DIV_ROUND_CLOSEST(x, divisor)(			\
61 {							\
62 	typeof(divisor) __divisor = divisor;		\
63 	(((x) + ((__divisor) / 2)) / (__divisor));	\
64 }							\
65 )
66 
67 #define _RET_IP_		(unsigned long)__builtin_return_address(0)
68 #define _THIS_IP_  ({ __label__ __here; __here: (unsigned long)&&__here; })
69 
70 #ifdef CONFIG_LBDAF
71 # include <asm/div64.h>
72 # define sector_div(a, b) do_div(a, b)
73 #else
74 # define sector_div(n, b)( \
75 { \
76 	int _res; \
77 	_res = (n) % (b); \
78 	(n) /= (b); \
79 	_res; \
80 } \
81 )
82 #endif
83 
84 /**
85  * upper_32_bits - return bits 32-63 of a number
86  * @n: the number we're accessing
87  *
88  * A basic shift-right of a 64- or 32-bit quantity.  Use this to suppress
89  * the "right shift count >= width of type" warning when that quantity is
90  * 32-bits.
91  */
92 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
93 
94 /**
95  * lower_32_bits - return bits 0-31 of a number
96  * @n: the number we're accessing
97  */
98 #define lower_32_bits(n) ((u32)(n))
99 
100 #define	KERN_EMERG	"<0>"	/* system is unusable			*/
101 #define	KERN_ALERT	"<1>"	/* action must be taken immediately	*/
102 #define	KERN_CRIT	"<2>"	/* critical conditions			*/
103 #define	KERN_ERR	"<3>"	/* error conditions			*/
104 #define	KERN_WARNING	"<4>"	/* warning conditions			*/
105 #define	KERN_NOTICE	"<5>"	/* normal but significant condition	*/
106 #define	KERN_INFO	"<6>"	/* informational			*/
107 #define	KERN_DEBUG	"<7>"	/* debug-level messages			*/
108 
109 /* Use the default kernel loglevel */
110 #define KERN_DEFAULT	"<d>"
111 /*
112  * Annotation for a "continued" line of log printout (only done after a
113  * line that had no enclosing \n). Only to be used by core/arch code
114  * during early bootup (a continued line is not SMP-safe otherwise).
115  */
116 #define	KERN_CONT	"<c>"
117 
118 extern int console_printk[];
119 
120 #define console_loglevel (console_printk[0])
121 #define default_message_loglevel (console_printk[1])
122 #define minimum_console_loglevel (console_printk[2])
123 #define default_console_loglevel (console_printk[3])
124 
125 struct completion;
126 struct pt_regs;
127 struct user;
128 
129 #ifdef CONFIG_PREEMPT_VOLUNTARY
130 extern int _cond_resched(void);
131 # define might_resched() _cond_resched()
132 #else
133 # define might_resched() do { } while (0)
134 #endif
135 
136 #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
137   void __might_sleep(const char *file, int line, int preempt_offset);
138 /**
139  * might_sleep - annotation for functions that can sleep
140  *
141  * this macro will print a stack trace if it is executed in an atomic
142  * context (spinlock, irq-handler, ...).
143  *
144  * This is a useful debugging help to be able to catch problems early and not
145  * be bitten later when the calling function happens to sleep when it is not
146  * supposed to.
147  */
148 # define might_sleep() \
149 	do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
150 #else
151   static inline void __might_sleep(const char *file, int line,
152 				   int preempt_offset) { }
153 # define might_sleep() do { might_resched(); } while (0)
154 #endif
155 
156 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
157 
158 #define abs(x) ({				\
159 		long __x = (x);			\
160 		(__x < 0) ? -__x : __x;		\
161 	})
162 
163 #ifdef CONFIG_PROVE_LOCKING
164 void might_fault(void);
165 #else
166 static inline void might_fault(void)
167 {
168 	might_sleep();
169 }
170 #endif
171 
172 extern struct atomic_notifier_head panic_notifier_list;
173 extern long (*panic_blink)(long time);
174 NORET_TYPE void panic(const char * fmt, ...)
175 	__attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
176 extern void oops_enter(void);
177 extern void oops_exit(void);
178 extern int oops_may_print(void);
179 NORET_TYPE void do_exit(long error_code)
180 	ATTRIB_NORET;
181 NORET_TYPE void complete_and_exit(struct completion *, long)
182 	ATTRIB_NORET;
183 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
184 extern long simple_strtol(const char *,char **,unsigned int);
185 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
186 extern long long simple_strtoll(const char *,char **,unsigned int);
187 extern int strict_strtoul(const char *, unsigned int, unsigned long *);
188 extern int strict_strtol(const char *, unsigned int, long *);
189 extern int strict_strtoull(const char *, unsigned int, unsigned long long *);
190 extern int strict_strtoll(const char *, unsigned int, long long *);
191 extern int sprintf(char * buf, const char * fmt, ...)
192 	__attribute__ ((format (printf, 2, 3)));
193 extern int vsprintf(char *buf, const char *, va_list)
194 	__attribute__ ((format (printf, 2, 0)));
195 extern int snprintf(char * buf, size_t size, const char * fmt, ...)
196 	__attribute__ ((format (printf, 3, 4)));
197 extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
198 	__attribute__ ((format (printf, 3, 0)));
199 extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
200 	__attribute__ ((format (printf, 3, 4)));
201 extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
202 	__attribute__ ((format (printf, 3, 0)));
203 extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
204 	__attribute__ ((format (printf, 2, 3)));
205 extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
206 
207 extern int sscanf(const char *, const char *, ...)
208 	__attribute__ ((format (scanf, 2, 3)));
209 extern int vsscanf(const char *, const char *, va_list)
210 	__attribute__ ((format (scanf, 2, 0)));
211 
212 extern int get_option(char **str, int *pint);
213 extern char *get_options(const char *str, int nints, int *ints);
214 extern unsigned long long memparse(const char *ptr, char **retptr);
215 
216 extern int core_kernel_text(unsigned long addr);
217 extern int __kernel_text_address(unsigned long addr);
218 extern int kernel_text_address(unsigned long addr);
219 extern int func_ptr_is_kernel_text(void *ptr);
220 
221 struct pid;
222 extern struct pid *session_of_pgrp(struct pid *pgrp);
223 
224 /*
225  * FW_BUG
226  * Add this to a message where you are sure the firmware is buggy or behaves
227  * really stupid or out of spec. Be aware that the responsible BIOS developer
228  * should be able to fix this issue or at least get a concrete idea of the
229  * problem by reading your message without the need of looking at the kernel
230  * code.
231  *
232  * Use it for definite and high priority BIOS bugs.
233  *
234  * FW_WARN
235  * Use it for not that clear (e.g. could the kernel messed up things already?)
236  * and medium priority BIOS bugs.
237  *
238  * FW_INFO
239  * Use this one if you want to tell the user or vendor about something
240  * suspicious, but generally harmless related to the firmware.
241  *
242  * Use it for information or very low priority BIOS bugs.
243  */
244 #define FW_BUG		"[Firmware Bug]: "
245 #define FW_WARN		"[Firmware Warn]: "
246 #define FW_INFO		"[Firmware Info]: "
247 
248 #ifdef CONFIG_PRINTK
249 asmlinkage int vprintk(const char *fmt, va_list args)
250 	__attribute__ ((format (printf, 1, 0)));
251 asmlinkage int printk(const char * fmt, ...)
252 	__attribute__ ((format (printf, 1, 2))) __cold;
253 
254 extern int __printk_ratelimit(const char *func);
255 #define printk_ratelimit() __printk_ratelimit(__func__)
256 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
257 				   unsigned int interval_msec);
258 
259 extern int printk_delay_msec;
260 
261 /*
262  * Print a one-time message (analogous to WARN_ONCE() et al):
263  */
264 #define printk_once(x...) ({			\
265 	static bool __print_once;		\
266 						\
267 	if (!__print_once) {			\
268 		__print_once = true;		\
269 		printk(x);			\
270 	}					\
271 })
272 
273 void log_buf_kexec_setup(void);
274 #else
275 static inline int vprintk(const char *s, va_list args)
276 	__attribute__ ((format (printf, 1, 0)));
277 static inline int vprintk(const char *s, va_list args) { return 0; }
278 static inline int printk(const char *s, ...)
279 	__attribute__ ((format (printf, 1, 2)));
280 static inline int __cold printk(const char *s, ...) { return 0; }
281 static inline int printk_ratelimit(void) { return 0; }
282 static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies, \
283 					  unsigned int interval_msec)	\
284 		{ return false; }
285 
286 /* No effect, but we still get type checking even in the !PRINTK case: */
287 #define printk_once(x...) printk(x)
288 
289 static inline void log_buf_kexec_setup(void)
290 {
291 }
292 #endif
293 
294 extern int printk_needs_cpu(int cpu);
295 extern void printk_tick(void);
296 
297 extern void asmlinkage __attribute__((format(printf, 1, 2)))
298 	early_printk(const char *fmt, ...);
299 
300 unsigned long int_sqrt(unsigned long);
301 
302 static inline void console_silent(void)
303 {
304 	console_loglevel = 0;
305 }
306 
307 static inline void console_verbose(void)
308 {
309 	if (console_loglevel)
310 		console_loglevel = 15;
311 }
312 
313 extern void bust_spinlocks(int yes);
314 extern void wake_up_klogd(void);
315 extern int oops_in_progress;		/* If set, an oops, panic(), BUG() or die() is in progress */
316 extern int panic_timeout;
317 extern int panic_on_oops;
318 extern int panic_on_unrecovered_nmi;
319 extern int panic_on_io_nmi;
320 extern const char *print_tainted(void);
321 extern void add_taint(unsigned flag);
322 extern int test_taint(unsigned flag);
323 extern unsigned long get_taint(void);
324 extern int root_mountflags;
325 
326 /* Values used for system_state */
327 extern enum system_states {
328 	SYSTEM_BOOTING,
329 	SYSTEM_RUNNING,
330 	SYSTEM_HALT,
331 	SYSTEM_POWER_OFF,
332 	SYSTEM_RESTART,
333 	SYSTEM_SUSPEND_DISK,
334 } system_state;
335 
336 #define TAINT_PROPRIETARY_MODULE	0
337 #define TAINT_FORCED_MODULE		1
338 #define TAINT_UNSAFE_SMP		2
339 #define TAINT_FORCED_RMMOD		3
340 #define TAINT_MACHINE_CHECK		4
341 #define TAINT_BAD_PAGE			5
342 #define TAINT_USER			6
343 #define TAINT_DIE			7
344 #define TAINT_OVERRIDDEN_ACPI_TABLE	8
345 #define TAINT_WARN			9
346 #define TAINT_CRAP			10
347 
348 extern void dump_stack(void) __cold;
349 
350 enum {
351 	DUMP_PREFIX_NONE,
352 	DUMP_PREFIX_ADDRESS,
353 	DUMP_PREFIX_OFFSET
354 };
355 extern void hex_dump_to_buffer(const void *buf, size_t len,
356 				int rowsize, int groupsize,
357 				char *linebuf, size_t linebuflen, bool ascii);
358 extern void print_hex_dump(const char *level, const char *prefix_str,
359 				int prefix_type, int rowsize, int groupsize,
360 				const void *buf, size_t len, bool ascii);
361 extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
362 			const void *buf, size_t len);
363 
364 extern const char hex_asc[];
365 #define hex_asc_lo(x)	hex_asc[((x) & 0x0f)]
366 #define hex_asc_hi(x)	hex_asc[((x) & 0xf0) >> 4]
367 
368 static inline char *pack_hex_byte(char *buf, u8 byte)
369 {
370 	*buf++ = hex_asc_hi(byte);
371 	*buf++ = hex_asc_lo(byte);
372 	return buf;
373 }
374 
375 #ifndef pr_fmt
376 #define pr_fmt(fmt) fmt
377 #endif
378 
379 #define pr_emerg(fmt, ...) \
380         printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
381 #define pr_alert(fmt, ...) \
382         printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
383 #define pr_crit(fmt, ...) \
384         printk(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
385 #define pr_err(fmt, ...) \
386         printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
387 #define pr_warning(fmt, ...) \
388         printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
389 #define pr_notice(fmt, ...) \
390         printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
391 #define pr_info(fmt, ...) \
392         printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
393 #define pr_cont(fmt, ...) \
394 	printk(KERN_CONT fmt, ##__VA_ARGS__)
395 
396 /* pr_devel() should produce zero code unless DEBUG is defined */
397 #ifdef DEBUG
398 #define pr_devel(fmt, ...) \
399 	printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
400 #else
401 #define pr_devel(fmt, ...) \
402 	({ if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); 0; })
403 #endif
404 
405 /* If you are writing a driver, please use dev_dbg instead */
406 #if defined(DEBUG)
407 #define pr_debug(fmt, ...) \
408 	printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
409 #elif defined(CONFIG_DYNAMIC_DEBUG)
410 /* dynamic_pr_debug() uses pr_fmt() internally so we don't need it here */
411 #define pr_debug(fmt, ...) \
412 	dynamic_pr_debug(fmt, ##__VA_ARGS__)
413 #else
414 #define pr_debug(fmt, ...) \
415 	({ if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); 0; })
416 #endif
417 
418 /*
419  * ratelimited messages with local ratelimit_state,
420  * no local ratelimit_state used in the !PRINTK case
421  */
422 #ifdef CONFIG_PRINTK
423 #define printk_ratelimited(fmt, ...)  ({		\
424 	static struct ratelimit_state _rs = {		\
425 		.interval = DEFAULT_RATELIMIT_INTERVAL, \
426 		.burst = DEFAULT_RATELIMIT_BURST,       \
427 	};                                              \
428 							\
429 	if (__ratelimit(&_rs))                          \
430 		printk(fmt, ##__VA_ARGS__);		\
431 })
432 #else
433 /* No effect, but we still get type checking even in the !PRINTK case: */
434 #define printk_ratelimited printk
435 #endif
436 
437 #define pr_emerg_ratelimited(fmt, ...) \
438 	printk_ratelimited(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
439 #define pr_alert_ratelimited(fmt, ...) \
440 	printk_ratelimited(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
441 #define pr_crit_ratelimited(fmt, ...) \
442 	printk_ratelimited(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
443 #define pr_err_ratelimited(fmt, ...) \
444 	printk_ratelimited(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
445 #define pr_warning_ratelimited(fmt, ...) \
446 	printk_ratelimited(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
447 #define pr_notice_ratelimited(fmt, ...) \
448 	printk_ratelimited(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
449 #define pr_info_ratelimited(fmt, ...) \
450 	printk_ratelimited(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
451 /* no pr_cont_ratelimited, don't do that... */
452 /* If you are writing a driver, please use dev_dbg instead */
453 #if defined(DEBUG)
454 #define pr_debug_ratelimited(fmt, ...) \
455 	printk_ratelimited(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
456 #else
457 #define pr_debug_ratelimited(fmt, ...) \
458 	({ if (0) printk_ratelimited(KERN_DEBUG pr_fmt(fmt), \
459 				     ##__VA_ARGS__); 0; })
460 #endif
461 
462 /*
463  * General tracing related utility functions - trace_printk(),
464  * tracing_on/tracing_off and tracing_start()/tracing_stop
465  *
466  * Use tracing_on/tracing_off when you want to quickly turn on or off
467  * tracing. It simply enables or disables the recording of the trace events.
468  * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
469  * file, which gives a means for the kernel and userspace to interact.
470  * Place a tracing_off() in the kernel where you want tracing to end.
471  * From user space, examine the trace, and then echo 1 > tracing_on
472  * to continue tracing.
473  *
474  * tracing_stop/tracing_start has slightly more overhead. It is used
475  * by things like suspend to ram where disabling the recording of the
476  * trace is not enough, but tracing must actually stop because things
477  * like calling smp_processor_id() may crash the system.
478  *
479  * Most likely, you want to use tracing_on/tracing_off.
480  */
481 #ifdef CONFIG_RING_BUFFER
482 void tracing_on(void);
483 void tracing_off(void);
484 /* trace_off_permanent stops recording with no way to bring it back */
485 void tracing_off_permanent(void);
486 int tracing_is_on(void);
487 #else
488 static inline void tracing_on(void) { }
489 static inline void tracing_off(void) { }
490 static inline void tracing_off_permanent(void) { }
491 static inline int tracing_is_on(void) { return 0; }
492 #endif
493 
494 enum ftrace_dump_mode {
495 	DUMP_NONE,
496 	DUMP_ALL,
497 	DUMP_ORIG,
498 };
499 
500 #ifdef CONFIG_TRACING
501 extern void tracing_start(void);
502 extern void tracing_stop(void);
503 extern void ftrace_off_permanent(void);
504 
505 extern void
506 ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3);
507 
508 static inline void __attribute__ ((format (printf, 1, 2)))
509 ____trace_printk_check_format(const char *fmt, ...)
510 {
511 }
512 #define __trace_printk_check_format(fmt, args...)			\
513 do {									\
514 	if (0)								\
515 		____trace_printk_check_format(fmt, ##args);		\
516 } while (0)
517 
518 /**
519  * trace_printk - printf formatting in the ftrace buffer
520  * @fmt: the printf format for printing
521  *
522  * Note: __trace_printk is an internal function for trace_printk and
523  *       the @ip is passed in via the trace_printk macro.
524  *
525  * This function allows a kernel developer to debug fast path sections
526  * that printk is not appropriate for. By scattering in various
527  * printk like tracing in the code, a developer can quickly see
528  * where problems are occurring.
529  *
530  * This is intended as a debugging tool for the developer only.
531  * Please refrain from leaving trace_printks scattered around in
532  * your code.
533  */
534 
535 #define trace_printk(fmt, args...)					\
536 do {									\
537 	__trace_printk_check_format(fmt, ##args);			\
538 	if (__builtin_constant_p(fmt)) {				\
539 		static const char *trace_printk_fmt			\
540 		  __attribute__((section("__trace_printk_fmt"))) =	\
541 			__builtin_constant_p(fmt) ? fmt : NULL;		\
542 									\
543 		__trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args);	\
544 	} else								\
545 		__trace_printk(_THIS_IP_, fmt, ##args);		\
546 } while (0)
547 
548 extern int
549 __trace_bprintk(unsigned long ip, const char *fmt, ...)
550 	__attribute__ ((format (printf, 2, 3)));
551 
552 extern int
553 __trace_printk(unsigned long ip, const char *fmt, ...)
554 	__attribute__ ((format (printf, 2, 3)));
555 
556 extern void trace_dump_stack(void);
557 
558 /*
559  * The double __builtin_constant_p is because gcc will give us an error
560  * if we try to allocate the static variable to fmt if it is not a
561  * constant. Even with the outer if statement.
562  */
563 #define ftrace_vprintk(fmt, vargs)					\
564 do {									\
565 	if (__builtin_constant_p(fmt)) {				\
566 		static const char *trace_printk_fmt			\
567 		  __attribute__((section("__trace_printk_fmt"))) =	\
568 			__builtin_constant_p(fmt) ? fmt : NULL;		\
569 									\
570 		__ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs);	\
571 	} else								\
572 		__ftrace_vprintk(_THIS_IP_, fmt, vargs);		\
573 } while (0)
574 
575 extern int
576 __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
577 
578 extern int
579 __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
580 
581 extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
582 #else
583 static inline void
584 ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) { }
585 static inline int
586 trace_printk(const char *fmt, ...) __attribute__ ((format (printf, 1, 2)));
587 
588 static inline void tracing_start(void) { }
589 static inline void tracing_stop(void) { }
590 static inline void ftrace_off_permanent(void) { }
591 static inline void trace_dump_stack(void) { }
592 static inline int
593 trace_printk(const char *fmt, ...)
594 {
595 	return 0;
596 }
597 static inline int
598 ftrace_vprintk(const char *fmt, va_list ap)
599 {
600 	return 0;
601 }
602 static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
603 #endif /* CONFIG_TRACING */
604 
605 /*
606  *      Display an IP address in readable format.
607  */
608 
609 #define NIPQUAD(addr) \
610 	((unsigned char *)&addr)[0], \
611 	((unsigned char *)&addr)[1], \
612 	((unsigned char *)&addr)[2], \
613 	((unsigned char *)&addr)[3]
614 #define NIPQUAD_FMT "%u.%u.%u.%u"
615 
616 /*
617  * min()/max()/clamp() macros that also do
618  * strict type-checking.. See the
619  * "unnecessary" pointer comparison.
620  */
621 #define min(x, y) ({				\
622 	typeof(x) _min1 = (x);			\
623 	typeof(y) _min2 = (y);			\
624 	(void) (&_min1 == &_min2);		\
625 	_min1 < _min2 ? _min1 : _min2; })
626 
627 #define max(x, y) ({				\
628 	typeof(x) _max1 = (x);			\
629 	typeof(y) _max2 = (y);			\
630 	(void) (&_max1 == &_max2);		\
631 	_max1 > _max2 ? _max1 : _max2; })
632 
633 /**
634  * clamp - return a value clamped to a given range with strict typechecking
635  * @val: current value
636  * @min: minimum allowable value
637  * @max: maximum allowable value
638  *
639  * This macro does strict typechecking of min/max to make sure they are of the
640  * same type as val.  See the unnecessary pointer comparisons.
641  */
642 #define clamp(val, min, max) ({			\
643 	typeof(val) __val = (val);		\
644 	typeof(min) __min = (min);		\
645 	typeof(max) __max = (max);		\
646 	(void) (&__val == &__min);		\
647 	(void) (&__val == &__max);		\
648 	__val = __val < __min ? __min: __val;	\
649 	__val > __max ? __max: __val; })
650 
651 /*
652  * ..and if you can't take the strict
653  * types, you can specify one yourself.
654  *
655  * Or not use min/max/clamp at all, of course.
656  */
657 #define min_t(type, x, y) ({			\
658 	type __min1 = (x);			\
659 	type __min2 = (y);			\
660 	__min1 < __min2 ? __min1: __min2; })
661 
662 #define max_t(type, x, y) ({			\
663 	type __max1 = (x);			\
664 	type __max2 = (y);			\
665 	__max1 > __max2 ? __max1: __max2; })
666 
667 /**
668  * clamp_t - return a value clamped to a given range using a given type
669  * @type: the type of variable to use
670  * @val: current value
671  * @min: minimum allowable value
672  * @max: maximum allowable value
673  *
674  * This macro does no typechecking and uses temporary variables of type
675  * 'type' to make all the comparisons.
676  */
677 #define clamp_t(type, val, min, max) ({		\
678 	type __val = (val);			\
679 	type __min = (min);			\
680 	type __max = (max);			\
681 	__val = __val < __min ? __min: __val;	\
682 	__val > __max ? __max: __val; })
683 
684 /**
685  * clamp_val - return a value clamped to a given range using val's type
686  * @val: current value
687  * @min: minimum allowable value
688  * @max: maximum allowable value
689  *
690  * This macro does no typechecking and uses temporary variables of whatever
691  * type the input argument 'val' is.  This is useful when val is an unsigned
692  * type and min and max are literals that will otherwise be assigned a signed
693  * integer type.
694  */
695 #define clamp_val(val, min, max) ({		\
696 	typeof(val) __val = (val);		\
697 	typeof(val) __min = (min);		\
698 	typeof(val) __max = (max);		\
699 	__val = __val < __min ? __min: __val;	\
700 	__val > __max ? __max: __val; })
701 
702 
703 /*
704  * swap - swap value of @a and @b
705  */
706 #define swap(a, b) \
707 	do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
708 
709 /**
710  * container_of - cast a member of a structure out to the containing structure
711  * @ptr:	the pointer to the member.
712  * @type:	the type of the container struct this is embedded in.
713  * @member:	the name of the member within the struct.
714  *
715  */
716 #define container_of(ptr, type, member) ({			\
717 	const typeof( ((type *)0)->member ) *__mptr = (ptr);	\
718 	(type *)( (char *)__mptr - offsetof(type,member) );})
719 
720 struct sysinfo;
721 extern int do_sysinfo(struct sysinfo *info);
722 
723 #endif /* __KERNEL__ */
724 
725 #ifndef __EXPORTED_HEADERS__
726 #ifndef __KERNEL__
727 #warning Attempt to use kernel headers from user space, see http://kernelnewbies.org/KernelHeaders
728 #endif /* __KERNEL__ */
729 #endif /* __EXPORTED_HEADERS__ */
730 
731 #define SI_LOAD_SHIFT	16
732 struct sysinfo {
733 	long uptime;			/* Seconds since boot */
734 	unsigned long loads[3];		/* 1, 5, and 15 minute load averages */
735 	unsigned long totalram;		/* Total usable main memory size */
736 	unsigned long freeram;		/* Available memory size */
737 	unsigned long sharedram;	/* Amount of shared memory */
738 	unsigned long bufferram;	/* Memory used by buffers */
739 	unsigned long totalswap;	/* Total swap space size */
740 	unsigned long freeswap;		/* swap space still available */
741 	unsigned short procs;		/* Number of current processes */
742 	unsigned short pad;		/* explicit padding for m68k */
743 	unsigned long totalhigh;	/* Total high memory size */
744 	unsigned long freehigh;		/* Available high memory size */
745 	unsigned int mem_unit;		/* Memory unit size in bytes */
746 	char _f[20-2*sizeof(long)-sizeof(int)];	/* Padding: libc5 uses this.. */
747 };
748 
749 /* Force a compilation error if condition is true */
750 #define BUILD_BUG_ON(condition) ((void)BUILD_BUG_ON_ZERO(condition))
751 
752 /* Force a compilation error if condition is constant and true */
753 #define MAYBE_BUILD_BUG_ON(cond) ((void)sizeof(char[1 - 2 * !!(cond)]))
754 
755 /* Force a compilation error if a constant expression is not a power of 2 */
756 #define BUILD_BUG_ON_NOT_POWER_OF_2(n)			\
757 	BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0))
758 
759 /* Force a compilation error if condition is true, but also produce a
760    result (of value 0 and type size_t), so the expression can be used
761    e.g. in a structure initializer (or where-ever else comma expressions
762    aren't permitted). */
763 #define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
764 #define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))
765 
766 /* Trap pasters of __FUNCTION__ at compile-time */
767 #define __FUNCTION__ (__func__)
768 
769 /* This helps us to avoid #ifdef CONFIG_NUMA */
770 #ifdef CONFIG_NUMA
771 #define NUMA_BUILD 1
772 #else
773 #define NUMA_BUILD 0
774 #endif
775 
776 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
777 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
778 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
779 #endif
780 
781 #endif
782