xref: /linux-6.15/include/linux/kernel.h (revision 930cc144)
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/ratelimit.h>
19 #include <linux/dynamic_printk.h>
20 #include <asm/byteorder.h>
21 #include <asm/bug.h>
22 
23 extern const char linux_banner[];
24 extern const char linux_proc_banner[];
25 
26 #define USHORT_MAX	((u16)(~0U))
27 #define SHORT_MAX	((s16)(USHORT_MAX>>1))
28 #define SHORT_MIN	(-SHORT_MAX - 1)
29 #define INT_MAX		((int)(~0U>>1))
30 #define INT_MIN		(-INT_MAX - 1)
31 #define UINT_MAX	(~0U)
32 #define LONG_MAX	((long)(~0UL>>1))
33 #define LONG_MIN	(-LONG_MAX - 1)
34 #define ULONG_MAX	(~0UL)
35 #define LLONG_MAX	((long long)(~0ULL>>1))
36 #define LLONG_MIN	(-LLONG_MAX - 1)
37 #define ULLONG_MAX	(~0ULL)
38 
39 #define STACK_MAGIC	0xdeadbeef
40 
41 #define ALIGN(x,a)		__ALIGN_MASK(x,(typeof(x))(a)-1)
42 #define __ALIGN_MASK(x,mask)	(((x)+(mask))&~(mask))
43 #define PTR_ALIGN(p, a)		((typeof(p))ALIGN((unsigned long)(p), (a)))
44 #define IS_ALIGNED(x, a)		(((x) & ((typeof(x))(a) - 1)) == 0)
45 
46 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
47 
48 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
49 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
50 #define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
51 
52 #define _RET_IP_		(unsigned long)__builtin_return_address(0)
53 #define _THIS_IP_  ({ __label__ __here; __here: (unsigned long)&&__here; })
54 
55 #ifdef CONFIG_LBD
56 # include <asm/div64.h>
57 # define sector_div(a, b) do_div(a, b)
58 #else
59 # define sector_div(n, b)( \
60 { \
61 	int _res; \
62 	_res = (n) % (b); \
63 	(n) /= (b); \
64 	_res; \
65 } \
66 )
67 #endif
68 
69 /**
70  * upper_32_bits - return bits 32-63 of a number
71  * @n: the number we're accessing
72  *
73  * A basic shift-right of a 64- or 32-bit quantity.  Use this to suppress
74  * the "right shift count >= width of type" warning when that quantity is
75  * 32-bits.
76  */
77 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
78 
79 /**
80  * lower_32_bits - return bits 0-31 of a number
81  * @n: the number we're accessing
82  */
83 #define lower_32_bits(n) ((u32)(n))
84 
85 #define	KERN_EMERG	"<0>"	/* system is unusable			*/
86 #define	KERN_ALERT	"<1>"	/* action must be taken immediately	*/
87 #define	KERN_CRIT	"<2>"	/* critical conditions			*/
88 #define	KERN_ERR	"<3>"	/* error conditions			*/
89 #define	KERN_WARNING	"<4>"	/* warning conditions			*/
90 #define	KERN_NOTICE	"<5>"	/* normal but significant condition	*/
91 #define	KERN_INFO	"<6>"	/* informational			*/
92 #define	KERN_DEBUG	"<7>"	/* debug-level messages			*/
93 
94 /*
95  * Annotation for a "continued" line of log printout (only done after a
96  * line that had no enclosing \n). Only to be used by core/arch code
97  * during early bootup (a continued line is not SMP-safe otherwise).
98  */
99 #define	KERN_CONT	""
100 
101 extern int console_printk[];
102 
103 #define console_loglevel (console_printk[0])
104 #define default_message_loglevel (console_printk[1])
105 #define minimum_console_loglevel (console_printk[2])
106 #define default_console_loglevel (console_printk[3])
107 
108 struct completion;
109 struct pt_regs;
110 struct user;
111 
112 #ifdef CONFIG_PREEMPT_VOLUNTARY
113 extern int _cond_resched(void);
114 # define might_resched() _cond_resched()
115 #else
116 # define might_resched() do { } while (0)
117 #endif
118 
119 /**
120  * might_sleep - annotation for functions that can sleep
121  *
122  * this macro will print a stack trace if it is executed in an atomic
123  * context (spinlock, irq-handler, ...).
124  *
125  * This is a useful debugging help to be able to catch problems early and not
126  * be bitten later when the calling function happens to sleep when it is not
127  * supposed to.
128  */
129 #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
130   void __might_sleep(char *file, int line);
131 # define might_sleep() \
132 	do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
133 #else
134 # define might_sleep() do { might_resched(); } while (0)
135 #endif
136 
137 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
138 
139 #define abs(x) ({				\
140 		int __x = (x);			\
141 		(__x < 0) ? -__x : __x;		\
142 	})
143 
144 extern struct atomic_notifier_head panic_notifier_list;
145 extern long (*panic_blink)(long time);
146 NORET_TYPE void panic(const char * fmt, ...)
147 	__attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
148 extern void oops_enter(void);
149 extern void oops_exit(void);
150 extern int oops_may_print(void);
151 NORET_TYPE void do_exit(long error_code)
152 	ATTRIB_NORET;
153 NORET_TYPE void complete_and_exit(struct completion *, long)
154 	ATTRIB_NORET;
155 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
156 extern long simple_strtol(const char *,char **,unsigned int);
157 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
158 extern long long simple_strtoll(const char *,char **,unsigned int);
159 extern int strict_strtoul(const char *, unsigned int, unsigned long *);
160 extern int strict_strtol(const char *, unsigned int, long *);
161 extern int strict_strtoull(const char *, unsigned int, unsigned long long *);
162 extern int strict_strtoll(const char *, unsigned int, long long *);
163 extern int sprintf(char * buf, const char * fmt, ...)
164 	__attribute__ ((format (printf, 2, 3)));
165 extern int vsprintf(char *buf, const char *, va_list)
166 	__attribute__ ((format (printf, 2, 0)));
167 extern int snprintf(char * buf, size_t size, const char * fmt, ...)
168 	__attribute__ ((format (printf, 3, 4)));
169 extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
170 	__attribute__ ((format (printf, 3, 0)));
171 extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
172 	__attribute__ ((format (printf, 3, 4)));
173 extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
174 	__attribute__ ((format (printf, 3, 0)));
175 extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
176 	__attribute__ ((format (printf, 2, 3)));
177 extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
178 
179 extern int sscanf(const char *, const char *, ...)
180 	__attribute__ ((format (scanf, 2, 3)));
181 extern int vsscanf(const char *, const char *, va_list)
182 	__attribute__ ((format (scanf, 2, 0)));
183 
184 extern int get_option(char **str, int *pint);
185 extern char *get_options(const char *str, int nints, int *ints);
186 extern unsigned long long memparse(const char *ptr, char **retptr);
187 
188 extern int core_kernel_text(unsigned long addr);
189 extern int __kernel_text_address(unsigned long addr);
190 extern int kernel_text_address(unsigned long addr);
191 struct pid;
192 extern struct pid *session_of_pgrp(struct pid *pgrp);
193 
194 #ifdef CONFIG_PRINTK
195 asmlinkage int vprintk(const char *fmt, va_list args)
196 	__attribute__ ((format (printf, 1, 0)));
197 asmlinkage int printk(const char * fmt, ...)
198 	__attribute__ ((format (printf, 1, 2))) __cold;
199 
200 extern struct ratelimit_state printk_ratelimit_state;
201 extern int printk_ratelimit(void);
202 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
203 				   unsigned int interval_msec);
204 #else
205 static inline int vprintk(const char *s, va_list args)
206 	__attribute__ ((format (printf, 1, 0)));
207 static inline int vprintk(const char *s, va_list args) { return 0; }
208 static inline int printk(const char *s, ...)
209 	__attribute__ ((format (printf, 1, 2)));
210 static inline int __cold printk(const char *s, ...) { return 0; }
211 static inline int printk_ratelimit(void) { return 0; }
212 static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies, \
213 					  unsigned int interval_msec)	\
214 		{ return false; }
215 #endif
216 
217 extern int printk_needs_cpu(int cpu);
218 extern void printk_tick(void);
219 
220 extern void asmlinkage __attribute__((format(printf, 1, 2)))
221 	early_printk(const char *fmt, ...);
222 
223 unsigned long int_sqrt(unsigned long);
224 
225 static inline void console_silent(void)
226 {
227 	console_loglevel = 0;
228 }
229 
230 static inline void console_verbose(void)
231 {
232 	if (console_loglevel)
233 		console_loglevel = 15;
234 }
235 
236 extern void bust_spinlocks(int yes);
237 extern void wake_up_klogd(void);
238 extern int oops_in_progress;		/* If set, an oops, panic(), BUG() or die() is in progress */
239 extern int panic_timeout;
240 extern int panic_on_oops;
241 extern int panic_on_unrecovered_nmi;
242 extern const char *print_tainted(void);
243 extern void add_taint(unsigned flag);
244 extern int test_taint(unsigned flag);
245 extern unsigned long get_taint(void);
246 extern int root_mountflags;
247 
248 /* Values used for system_state */
249 extern enum system_states {
250 	SYSTEM_BOOTING,
251 	SYSTEM_RUNNING,
252 	SYSTEM_HALT,
253 	SYSTEM_POWER_OFF,
254 	SYSTEM_RESTART,
255 	SYSTEM_SUSPEND_DISK,
256 } system_state;
257 
258 #define TAINT_PROPRIETARY_MODULE	0
259 #define TAINT_FORCED_MODULE		1
260 #define TAINT_UNSAFE_SMP		2
261 #define TAINT_FORCED_RMMOD		3
262 #define TAINT_MACHINE_CHECK		4
263 #define TAINT_BAD_PAGE			5
264 #define TAINT_USER			6
265 #define TAINT_DIE			7
266 #define TAINT_OVERRIDDEN_ACPI_TABLE	8
267 #define TAINT_WARN			9
268 #define TAINT_CRAP			10
269 
270 extern void dump_stack(void) __cold;
271 
272 enum {
273 	DUMP_PREFIX_NONE,
274 	DUMP_PREFIX_ADDRESS,
275 	DUMP_PREFIX_OFFSET
276 };
277 extern void hex_dump_to_buffer(const void *buf, size_t len,
278 				int rowsize, int groupsize,
279 				char *linebuf, size_t linebuflen, bool ascii);
280 extern void print_hex_dump(const char *level, const char *prefix_str,
281 				int prefix_type, int rowsize, int groupsize,
282 				const void *buf, size_t len, bool ascii);
283 extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
284 			const void *buf, size_t len);
285 
286 extern const char hex_asc[];
287 #define hex_asc_lo(x)	hex_asc[((x) & 0x0f)]
288 #define hex_asc_hi(x)	hex_asc[((x) & 0xf0) >> 4]
289 
290 static inline char *pack_hex_byte(char *buf, u8 byte)
291 {
292 	*buf++ = hex_asc_hi(byte);
293 	*buf++ = hex_asc_lo(byte);
294 	return buf;
295 }
296 
297 #define pr_emerg(fmt, arg...) \
298 	printk(KERN_EMERG fmt, ##arg)
299 #define pr_alert(fmt, arg...) \
300 	printk(KERN_ALERT fmt, ##arg)
301 #define pr_crit(fmt, arg...) \
302 	printk(KERN_CRIT fmt, ##arg)
303 #define pr_err(fmt, arg...) \
304 	printk(KERN_ERR fmt, ##arg)
305 #define pr_warning(fmt, arg...) \
306 	printk(KERN_WARNING fmt, ##arg)
307 #define pr_notice(fmt, arg...) \
308 	printk(KERN_NOTICE fmt, ##arg)
309 #define pr_info(fmt, arg...) \
310 	printk(KERN_INFO fmt, ##arg)
311 
312 /* If you are writing a driver, please use dev_dbg instead */
313 #if defined(CONFIG_DYNAMIC_PRINTK_DEBUG)
314 #define pr_debug(fmt, ...) do { \
315 	dynamic_pr_debug(fmt, ##__VA_ARGS__); \
316 	} while (0)
317 #elif defined(DEBUG)
318 #define pr_debug(fmt, arg...) \
319 	printk(KERN_DEBUG fmt, ##arg)
320 #else
321 #define pr_debug(fmt, arg...) \
322 	({ if (0) printk(KERN_DEBUG fmt, ##arg); 0; })
323 #endif
324 
325 /*
326  *      Display an IP address in readable format.
327  */
328 
329 #define NIPQUAD(addr) \
330 	((unsigned char *)&addr)[0], \
331 	((unsigned char *)&addr)[1], \
332 	((unsigned char *)&addr)[2], \
333 	((unsigned char *)&addr)[3]
334 #define NIPQUAD_FMT "%u.%u.%u.%u"
335 
336 #define NIP6(addr) \
337 	ntohs((addr).s6_addr16[0]), \
338 	ntohs((addr).s6_addr16[1]), \
339 	ntohs((addr).s6_addr16[2]), \
340 	ntohs((addr).s6_addr16[3]), \
341 	ntohs((addr).s6_addr16[4]), \
342 	ntohs((addr).s6_addr16[5]), \
343 	ntohs((addr).s6_addr16[6]), \
344 	ntohs((addr).s6_addr16[7])
345 #define NIP6_FMT "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x"
346 #define NIP6_SEQFMT "%04x%04x%04x%04x%04x%04x%04x%04x"
347 
348 #if defined(__LITTLE_ENDIAN)
349 #define HIPQUAD(addr) \
350 	((unsigned char *)&addr)[3], \
351 	((unsigned char *)&addr)[2], \
352 	((unsigned char *)&addr)[1], \
353 	((unsigned char *)&addr)[0]
354 #elif defined(__BIG_ENDIAN)
355 #define HIPQUAD	NIPQUAD
356 #else
357 #error "Please fix asm/byteorder.h"
358 #endif /* __LITTLE_ENDIAN */
359 
360 /*
361  * min()/max()/clamp() macros that also do
362  * strict type-checking.. See the
363  * "unnecessary" pointer comparison.
364  */
365 #define min(x, y) ({				\
366 	typeof(x) _min1 = (x);			\
367 	typeof(y) _min2 = (y);			\
368 	(void) (&_min1 == &_min2);		\
369 	_min1 < _min2 ? _min1 : _min2; })
370 
371 #define max(x, y) ({				\
372 	typeof(x) _max1 = (x);			\
373 	typeof(y) _max2 = (y);			\
374 	(void) (&_max1 == &_max2);		\
375 	_max1 > _max2 ? _max1 : _max2; })
376 
377 /**
378  * clamp - return a value clamped to a given range with strict typechecking
379  * @val: current value
380  * @min: minimum allowable value
381  * @max: maximum allowable value
382  *
383  * This macro does strict typechecking of min/max to make sure they are of the
384  * same type as val.  See the unnecessary pointer comparisons.
385  */
386 #define clamp(val, min, max) ({			\
387 	typeof(val) __val = (val);		\
388 	typeof(min) __min = (min);		\
389 	typeof(max) __max = (max);		\
390 	(void) (&__val == &__min);		\
391 	(void) (&__val == &__max);		\
392 	__val = __val < __min ? __min: __val;	\
393 	__val > __max ? __max: __val; })
394 
395 /*
396  * ..and if you can't take the strict
397  * types, you can specify one yourself.
398  *
399  * Or not use min/max/clamp at all, of course.
400  */
401 #define min_t(type, x, y) ({			\
402 	type __min1 = (x);			\
403 	type __min2 = (y);			\
404 	__min1 < __min2 ? __min1: __min2; })
405 
406 #define max_t(type, x, y) ({			\
407 	type __max1 = (x);			\
408 	type __max2 = (y);			\
409 	__max1 > __max2 ? __max1: __max2; })
410 
411 /**
412  * clamp_t - return a value clamped to a given range using a given type
413  * @type: the type of variable to use
414  * @val: current value
415  * @min: minimum allowable value
416  * @max: maximum allowable value
417  *
418  * This macro does no typechecking and uses temporary variables of type
419  * 'type' to make all the comparisons.
420  */
421 #define clamp_t(type, val, min, max) ({		\
422 	type __val = (val);			\
423 	type __min = (min);			\
424 	type __max = (max);			\
425 	__val = __val < __min ? __min: __val;	\
426 	__val > __max ? __max: __val; })
427 
428 /**
429  * clamp_val - return a value clamped to a given range using val's type
430  * @val: current value
431  * @min: minimum allowable value
432  * @max: maximum allowable value
433  *
434  * This macro does no typechecking and uses temporary variables of whatever
435  * type the input argument 'val' is.  This is useful when val is an unsigned
436  * type and min and max are literals that will otherwise be assigned a signed
437  * integer type.
438  */
439 #define clamp_val(val, min, max) ({		\
440 	typeof(val) __val = (val);		\
441 	typeof(val) __min = (min);		\
442 	typeof(val) __max = (max);		\
443 	__val = __val < __min ? __min: __val;	\
444 	__val > __max ? __max: __val; })
445 
446 /**
447  * container_of - cast a member of a structure out to the containing structure
448  * @ptr:	the pointer to the member.
449  * @type:	the type of the container struct this is embedded in.
450  * @member:	the name of the member within the struct.
451  *
452  */
453 #define container_of(ptr, type, member) ({			\
454 	const typeof( ((type *)0)->member ) *__mptr = (ptr);	\
455 	(type *)( (char *)__mptr - offsetof(type,member) );})
456 
457 struct sysinfo;
458 extern int do_sysinfo(struct sysinfo *info);
459 
460 #endif /* __KERNEL__ */
461 
462 #define SI_LOAD_SHIFT	16
463 struct sysinfo {
464 	long uptime;			/* Seconds since boot */
465 	unsigned long loads[3];		/* 1, 5, and 15 minute load averages */
466 	unsigned long totalram;		/* Total usable main memory size */
467 	unsigned long freeram;		/* Available memory size */
468 	unsigned long sharedram;	/* Amount of shared memory */
469 	unsigned long bufferram;	/* Memory used by buffers */
470 	unsigned long totalswap;	/* Total swap space size */
471 	unsigned long freeswap;		/* swap space still available */
472 	unsigned short procs;		/* Number of current processes */
473 	unsigned short pad;		/* explicit padding for m68k */
474 	unsigned long totalhigh;	/* Total high memory size */
475 	unsigned long freehigh;		/* Available high memory size */
476 	unsigned int mem_unit;		/* Memory unit size in bytes */
477 	char _f[20-2*sizeof(long)-sizeof(int)];	/* Padding: libc5 uses this.. */
478 };
479 
480 /* Force a compilation error if condition is true */
481 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
482 
483 /* Force a compilation error if condition is true, but also produce a
484    result (of value 0 and type size_t), so the expression can be used
485    e.g. in a structure initializer (or where-ever else comma expressions
486    aren't permitted). */
487 #define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
488 
489 /* Trap pasters of __FUNCTION__ at compile-time */
490 #define __FUNCTION__ (__func__)
491 
492 /* This helps us to avoid #ifdef CONFIG_NUMA */
493 #ifdef CONFIG_NUMA
494 #define NUMA_BUILD 1
495 #else
496 #define NUMA_BUILD 0
497 #endif
498 
499 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
500 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
501 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
502 #endif
503 
504 #endif
505