xref: /linux-6.15/include/linux/printk.h (revision aff985fd)
1 #ifndef __KERNEL_PRINTK__
2 #define __KERNEL_PRINTK__
3 
4 #include <stdarg.h>
5 #include <linux/init.h>
6 #include <linux/kern_levels.h>
7 #include <linux/linkage.h>
8 #include <linux/cache.h>
9 
10 extern const char linux_banner[];
11 extern const char linux_proc_banner[];
12 
13 #define PRINTK_MAX_SINGLE_HEADER_LEN 2
14 
15 static inline int printk_get_level(const char *buffer)
16 {
17 	if (buffer[0] == KERN_SOH_ASCII && buffer[1]) {
18 		switch (buffer[1]) {
19 		case '0' ... '7':
20 		case 'd':	/* KERN_DEFAULT */
21 		case 'c':	/* KERN_CONT */
22 			return buffer[1];
23 		}
24 	}
25 	return 0;
26 }
27 
28 static inline const char *printk_skip_level(const char *buffer)
29 {
30 	if (printk_get_level(buffer))
31 		return buffer + 2;
32 
33 	return buffer;
34 }
35 
36 static inline const char *printk_skip_headers(const char *buffer)
37 {
38 	while (printk_get_level(buffer))
39 		buffer = printk_skip_level(buffer);
40 
41 	return buffer;
42 }
43 
44 #define CONSOLE_EXT_LOG_MAX	8192
45 
46 /* printk's without a loglevel use this.. */
47 #define MESSAGE_LOGLEVEL_DEFAULT CONFIG_MESSAGE_LOGLEVEL_DEFAULT
48 
49 /* We show everything that is MORE important than this.. */
50 #define CONSOLE_LOGLEVEL_SILENT  0 /* Mum's the word */
51 #define CONSOLE_LOGLEVEL_MIN	 1 /* Minimum loglevel we let people use */
52 #define CONSOLE_LOGLEVEL_QUIET	 4 /* Shhh ..., when booted with "quiet" */
53 #define CONSOLE_LOGLEVEL_DEBUG	10 /* issue debug messages */
54 #define CONSOLE_LOGLEVEL_MOTORMOUTH 15	/* You can't shut this one up */
55 
56 /*
57  * Default used to be hard-coded at 7, we're now allowing it to be set from
58  * kernel config.
59  */
60 #define CONSOLE_LOGLEVEL_DEFAULT CONFIG_CONSOLE_LOGLEVEL_DEFAULT
61 
62 extern int console_printk[];
63 
64 #define console_loglevel (console_printk[0])
65 #define default_message_loglevel (console_printk[1])
66 #define minimum_console_loglevel (console_printk[2])
67 #define default_console_loglevel (console_printk[3])
68 
69 static inline void console_silent(void)
70 {
71 	console_loglevel = CONSOLE_LOGLEVEL_SILENT;
72 }
73 
74 static inline void console_verbose(void)
75 {
76 	if (console_loglevel)
77 		console_loglevel = CONSOLE_LOGLEVEL_MOTORMOUTH;
78 }
79 
80 /* strlen("ratelimit") + 1 */
81 #define DEVKMSG_STR_MAX_SIZE 10
82 extern char devkmsg_log_str[];
83 struct ctl_table;
84 
85 struct va_format {
86 	const char *fmt;
87 	va_list *va;
88 };
89 
90 /*
91  * FW_BUG
92  * Add this to a message where you are sure the firmware is buggy or behaves
93  * really stupid or out of spec. Be aware that the responsible BIOS developer
94  * should be able to fix this issue or at least get a concrete idea of the
95  * problem by reading your message without the need of looking at the kernel
96  * code.
97  *
98  * Use it for definite and high priority BIOS bugs.
99  *
100  * FW_WARN
101  * Use it for not that clear (e.g. could the kernel messed up things already?)
102  * and medium priority BIOS bugs.
103  *
104  * FW_INFO
105  * Use this one if you want to tell the user or vendor about something
106  * suspicious, but generally harmless related to the firmware.
107  *
108  * Use it for information or very low priority BIOS bugs.
109  */
110 #define FW_BUG		"[Firmware Bug]: "
111 #define FW_WARN		"[Firmware Warn]: "
112 #define FW_INFO		"[Firmware Info]: "
113 
114 /*
115  * HW_ERR
116  * Add this to a message for hardware errors, so that user can report
117  * it to hardware vendor instead of LKML or software vendor.
118  */
119 #define HW_ERR		"[Hardware Error]: "
120 
121 /*
122  * DEPRECATED
123  * Add this to a message whenever you want to warn user space about the use
124  * of a deprecated aspect of an API so they can stop using it
125  */
126 #define DEPRECATED	"[Deprecated]: "
127 
128 /*
129  * Dummy printk for disabled debugging statements to use whilst maintaining
130  * gcc's format checking.
131  */
132 #define no_printk(fmt, ...)				\
133 ({							\
134 	do {						\
135 		if (0)					\
136 			printk(fmt, ##__VA_ARGS__);	\
137 	} while (0);					\
138 	0;						\
139 })
140 
141 #ifdef CONFIG_EARLY_PRINTK
142 extern asmlinkage __printf(1, 2)
143 void early_printk(const char *fmt, ...);
144 #else
145 static inline __printf(1, 2) __cold
146 void early_printk(const char *s, ...) { }
147 #endif
148 
149 #ifdef CONFIG_PRINTK_NMI
150 extern void printk_nmi_init(void);
151 extern void printk_nmi_enter(void);
152 extern void printk_nmi_exit(void);
153 extern void printk_nmi_flush(void);
154 extern void printk_nmi_flush_on_panic(void);
155 #else
156 static inline void printk_nmi_init(void) { }
157 static inline void printk_nmi_enter(void) { }
158 static inline void printk_nmi_exit(void) { }
159 static inline void printk_nmi_flush(void) { }
160 static inline void printk_nmi_flush_on_panic(void) { }
161 #endif /* PRINTK_NMI */
162 
163 #ifdef CONFIG_PRINTK
164 asmlinkage __printf(5, 0)
165 int vprintk_emit(int facility, int level,
166 		 const char *dict, size_t dictlen,
167 		 const char *fmt, va_list args);
168 
169 asmlinkage __printf(1, 0)
170 int vprintk(const char *fmt, va_list args);
171 
172 asmlinkage __printf(5, 6) __cold
173 int printk_emit(int facility, int level,
174 		const char *dict, size_t dictlen,
175 		const char *fmt, ...);
176 
177 asmlinkage __printf(1, 2) __cold
178 int printk(const char *fmt, ...);
179 
180 /*
181  * Special printk facility for scheduler/timekeeping use only, _DO_NOT_USE_ !
182  */
183 __printf(1, 2) __cold int printk_deferred(const char *fmt, ...);
184 
185 /*
186  * Please don't use printk_ratelimit(), because it shares ratelimiting state
187  * with all other unrelated printk_ratelimit() callsites.  Instead use
188  * printk_ratelimited() or plain old __ratelimit().
189  */
190 extern int __printk_ratelimit(const char *func);
191 #define printk_ratelimit() __printk_ratelimit(__func__)
192 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
193 				   unsigned int interval_msec);
194 
195 extern int printk_delay_msec;
196 extern int dmesg_restrict;
197 extern int kptr_restrict;
198 
199 extern int
200 devkmsg_sysctl_set_loglvl(struct ctl_table *table, int write, void __user *buf,
201 			  size_t *lenp, loff_t *ppos);
202 
203 extern void wake_up_klogd(void);
204 
205 char *log_buf_addr_get(void);
206 u32 log_buf_len_get(void);
207 void log_buf_kexec_setup(void);
208 void __init setup_log_buf(int early);
209 __printf(1, 2) void dump_stack_set_arch_desc(const char *fmt, ...);
210 void dump_stack_print_info(const char *log_lvl);
211 void show_regs_print_info(const char *log_lvl);
212 #else
213 static inline __printf(1, 0)
214 int vprintk(const char *s, va_list args)
215 {
216 	return 0;
217 }
218 static inline __printf(1, 2) __cold
219 int printk(const char *s, ...)
220 {
221 	return 0;
222 }
223 static inline __printf(1, 2) __cold
224 int printk_deferred(const char *s, ...)
225 {
226 	return 0;
227 }
228 static inline int printk_ratelimit(void)
229 {
230 	return 0;
231 }
232 static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies,
233 					  unsigned int interval_msec)
234 {
235 	return false;
236 }
237 
238 static inline void wake_up_klogd(void)
239 {
240 }
241 
242 static inline char *log_buf_addr_get(void)
243 {
244 	return NULL;
245 }
246 
247 static inline u32 log_buf_len_get(void)
248 {
249 	return 0;
250 }
251 
252 static inline void log_buf_kexec_setup(void)
253 {
254 }
255 
256 static inline void setup_log_buf(int early)
257 {
258 }
259 
260 static inline __printf(1, 2) void dump_stack_set_arch_desc(const char *fmt, ...)
261 {
262 }
263 
264 static inline void dump_stack_print_info(const char *log_lvl)
265 {
266 }
267 
268 static inline void show_regs_print_info(const char *log_lvl)
269 {
270 }
271 #endif
272 
273 extern asmlinkage void dump_stack(void) __cold;
274 
275 #ifndef pr_fmt
276 #define pr_fmt(fmt) fmt
277 #endif
278 
279 /*
280  * These can be used to print at the various log levels.
281  * All of these will print unconditionally, although note that pr_debug()
282  * and other debug macros are compiled out unless either DEBUG is defined
283  * or CONFIG_DYNAMIC_DEBUG is set.
284  */
285 #define pr_emerg(fmt, ...) \
286 	printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
287 #define pr_alert(fmt, ...) \
288 	printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
289 #define pr_crit(fmt, ...) \
290 	printk(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
291 #define pr_err(fmt, ...) \
292 	printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
293 #define pr_warning(fmt, ...) \
294 	printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
295 #define pr_warn pr_warning
296 #define pr_notice(fmt, ...) \
297 	printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
298 #define pr_info(fmt, ...) \
299 	printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
300 /*
301  * Like KERN_CONT, pr_cont() should only be used when continuing
302  * a line with no newline ('\n') enclosed. Otherwise it defaults
303  * back to KERN_DEFAULT.
304  */
305 #define pr_cont(fmt, ...) \
306 	printk(KERN_CONT fmt, ##__VA_ARGS__)
307 
308 /* pr_devel() should produce zero code unless DEBUG is defined */
309 #ifdef DEBUG
310 #define pr_devel(fmt, ...) \
311 	printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
312 #else
313 #define pr_devel(fmt, ...) \
314 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
315 #endif
316 
317 
318 /* If you are writing a driver, please use dev_dbg instead */
319 #if defined(CONFIG_DYNAMIC_DEBUG)
320 #include <linux/dynamic_debug.h>
321 
322 /* dynamic_pr_debug() uses pr_fmt() internally so we don't need it here */
323 #define pr_debug(fmt, ...) \
324 	dynamic_pr_debug(fmt, ##__VA_ARGS__)
325 #elif defined(DEBUG)
326 #define pr_debug(fmt, ...) \
327 	printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
328 #else
329 #define pr_debug(fmt, ...) \
330 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
331 #endif
332 
333 /*
334  * Print a one-time message (analogous to WARN_ONCE() et al):
335  */
336 
337 #ifdef CONFIG_PRINTK
338 #define printk_once(fmt, ...)					\
339 ({								\
340 	static bool __print_once __read_mostly;			\
341 	bool __ret_print_once = !__print_once;			\
342 								\
343 	if (!__print_once) {					\
344 		__print_once = true;				\
345 		printk(fmt, ##__VA_ARGS__);			\
346 	}							\
347 	unlikely(__ret_print_once);				\
348 })
349 #define printk_deferred_once(fmt, ...)				\
350 ({								\
351 	static bool __print_once __read_mostly;			\
352 	bool __ret_print_once = !__print_once;			\
353 								\
354 	if (!__print_once) {					\
355 		__print_once = true;				\
356 		printk_deferred(fmt, ##__VA_ARGS__);		\
357 	}							\
358 	unlikely(__ret_print_once);				\
359 })
360 #else
361 #define printk_once(fmt, ...)					\
362 	no_printk(fmt, ##__VA_ARGS__)
363 #define printk_deferred_once(fmt, ...)				\
364 	no_printk(fmt, ##__VA_ARGS__)
365 #endif
366 
367 #define pr_emerg_once(fmt, ...)					\
368 	printk_once(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
369 #define pr_alert_once(fmt, ...)					\
370 	printk_once(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
371 #define pr_crit_once(fmt, ...)					\
372 	printk_once(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
373 #define pr_err_once(fmt, ...)					\
374 	printk_once(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
375 #define pr_warn_once(fmt, ...)					\
376 	printk_once(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
377 #define pr_notice_once(fmt, ...)				\
378 	printk_once(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
379 #define pr_info_once(fmt, ...)					\
380 	printk_once(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
381 #define pr_cont_once(fmt, ...)					\
382 	printk_once(KERN_CONT pr_fmt(fmt), ##__VA_ARGS__)
383 
384 #if defined(DEBUG)
385 #define pr_devel_once(fmt, ...)					\
386 	printk_once(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
387 #else
388 #define pr_devel_once(fmt, ...)					\
389 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
390 #endif
391 
392 /* If you are writing a driver, please use dev_dbg instead */
393 #if defined(DEBUG)
394 #define pr_debug_once(fmt, ...)					\
395 	printk_once(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
396 #else
397 #define pr_debug_once(fmt, ...)					\
398 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
399 #endif
400 
401 /*
402  * ratelimited messages with local ratelimit_state,
403  * no local ratelimit_state used in the !PRINTK case
404  */
405 #ifdef CONFIG_PRINTK
406 #define printk_ratelimited(fmt, ...)					\
407 ({									\
408 	static DEFINE_RATELIMIT_STATE(_rs,				\
409 				      DEFAULT_RATELIMIT_INTERVAL,	\
410 				      DEFAULT_RATELIMIT_BURST);		\
411 									\
412 	if (__ratelimit(&_rs))						\
413 		printk(fmt, ##__VA_ARGS__);				\
414 })
415 #else
416 #define printk_ratelimited(fmt, ...)					\
417 	no_printk(fmt, ##__VA_ARGS__)
418 #endif
419 
420 #define pr_emerg_ratelimited(fmt, ...)					\
421 	printk_ratelimited(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
422 #define pr_alert_ratelimited(fmt, ...)					\
423 	printk_ratelimited(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
424 #define pr_crit_ratelimited(fmt, ...)					\
425 	printk_ratelimited(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
426 #define pr_err_ratelimited(fmt, ...)					\
427 	printk_ratelimited(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
428 #define pr_warn_ratelimited(fmt, ...)					\
429 	printk_ratelimited(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
430 #define pr_notice_ratelimited(fmt, ...)					\
431 	printk_ratelimited(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
432 #define pr_info_ratelimited(fmt, ...)					\
433 	printk_ratelimited(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
434 /* no pr_cont_ratelimited, don't do that... */
435 
436 #if defined(DEBUG)
437 #define pr_devel_ratelimited(fmt, ...)					\
438 	printk_ratelimited(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
439 #else
440 #define pr_devel_ratelimited(fmt, ...)					\
441 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
442 #endif
443 
444 /* If you are writing a driver, please use dev_dbg instead */
445 #if defined(CONFIG_DYNAMIC_DEBUG)
446 /* descriptor check is first to prevent flooding with "callbacks suppressed" */
447 #define pr_debug_ratelimited(fmt, ...)					\
448 do {									\
449 	static DEFINE_RATELIMIT_STATE(_rs,				\
450 				      DEFAULT_RATELIMIT_INTERVAL,	\
451 				      DEFAULT_RATELIMIT_BURST);		\
452 	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, pr_fmt(fmt));		\
453 	if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT) &&	\
454 	    __ratelimit(&_rs))						\
455 		__dynamic_pr_debug(&descriptor, pr_fmt(fmt), ##__VA_ARGS__);	\
456 } while (0)
457 #elif defined(DEBUG)
458 #define pr_debug_ratelimited(fmt, ...)					\
459 	printk_ratelimited(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
460 #else
461 #define pr_debug_ratelimited(fmt, ...) \
462 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
463 #endif
464 
465 extern const struct file_operations kmsg_fops;
466 
467 enum {
468 	DUMP_PREFIX_NONE,
469 	DUMP_PREFIX_ADDRESS,
470 	DUMP_PREFIX_OFFSET
471 };
472 extern int hex_dump_to_buffer(const void *buf, size_t len, int rowsize,
473 			      int groupsize, char *linebuf, size_t linebuflen,
474 			      bool ascii);
475 #ifdef CONFIG_PRINTK
476 extern void print_hex_dump(const char *level, const char *prefix_str,
477 			   int prefix_type, int rowsize, int groupsize,
478 			   const void *buf, size_t len, bool ascii);
479 #if defined(CONFIG_DYNAMIC_DEBUG)
480 #define print_hex_dump_bytes(prefix_str, prefix_type, buf, len)	\
481 	dynamic_hex_dump(prefix_str, prefix_type, 16, 1, buf, len, true)
482 #else
483 extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
484 				 const void *buf, size_t len);
485 #endif /* defined(CONFIG_DYNAMIC_DEBUG) */
486 #else
487 static inline void print_hex_dump(const char *level, const char *prefix_str,
488 				  int prefix_type, int rowsize, int groupsize,
489 				  const void *buf, size_t len, bool ascii)
490 {
491 }
492 static inline void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
493 					const void *buf, size_t len)
494 {
495 }
496 
497 #endif
498 
499 #if defined(CONFIG_DYNAMIC_DEBUG)
500 #define print_hex_dump_debug(prefix_str, prefix_type, rowsize,	\
501 			     groupsize, buf, len, ascii)	\
502 	dynamic_hex_dump(prefix_str, prefix_type, rowsize,	\
503 			 groupsize, buf, len, ascii)
504 #elif defined(DEBUG)
505 #define print_hex_dump_debug(prefix_str, prefix_type, rowsize,		\
506 			     groupsize, buf, len, ascii)		\
507 	print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, rowsize,	\
508 		       groupsize, buf, len, ascii)
509 #else
510 static inline void print_hex_dump_debug(const char *prefix_str, int prefix_type,
511 					int rowsize, int groupsize,
512 					const void *buf, size_t len, bool ascii)
513 {
514 }
515 #endif
516 
517 #endif
518