xref: /linux-6.15/include/linux/printk.h (revision 228cd2db)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __KERNEL_PRINTK__
3 #define __KERNEL_PRINTK__
4 
5 #include <stdarg.h>
6 #include <linux/init.h>
7 #include <linux/kern_levels.h>
8 #include <linux/linkage.h>
9 #include <linux/cache.h>
10 
11 extern const char linux_banner[];
12 extern const char linux_proc_banner[];
13 
14 #define PRINTK_MAX_SINGLE_HEADER_LEN 2
15 
16 static inline int printk_get_level(const char *buffer)
17 {
18 	if (buffer[0] == KERN_SOH_ASCII && buffer[1]) {
19 		switch (buffer[1]) {
20 		case '0' ... '7':
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_DEBUG	10 /* issue debug messages */
53 #define CONSOLE_LOGLEVEL_MOTORMOUTH 15	/* You can't shut this one up */
54 
55 /*
56  * Default used to be hard-coded at 7, quiet used to be hardcoded at 4,
57  * we're now allowing both to be set from kernel config.
58  */
59 #define CONSOLE_LOGLEVEL_DEFAULT CONFIG_CONSOLE_LOGLEVEL_DEFAULT
60 #define CONSOLE_LOGLEVEL_QUIET	 CONFIG_CONSOLE_LOGLEVEL_QUIET
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 	if (0)						\
135 		printk(fmt, ##__VA_ARGS__);		\
136 	0;						\
137 })
138 
139 #ifdef CONFIG_EARLY_PRINTK
140 extern asmlinkage __printf(1, 2)
141 void early_printk(const char *fmt, ...);
142 #else
143 static inline __printf(1, 2) __cold
144 void early_printk(const char *s, ...) { }
145 #endif
146 
147 #ifdef CONFIG_PRINTK_NMI
148 extern void printk_nmi_enter(void);
149 extern void printk_nmi_exit(void);
150 extern void printk_nmi_direct_enter(void);
151 extern void printk_nmi_direct_exit(void);
152 #else
153 static inline void printk_nmi_enter(void) { }
154 static inline void printk_nmi_exit(void) { }
155 static inline void printk_nmi_direct_enter(void) { }
156 static inline void printk_nmi_direct_exit(void) { }
157 #endif /* PRINTK_NMI */
158 
159 #ifdef CONFIG_PRINTK
160 asmlinkage __printf(5, 0)
161 int vprintk_emit(int facility, int level,
162 		 const char *dict, size_t dictlen,
163 		 const char *fmt, va_list args);
164 
165 asmlinkage __printf(1, 0)
166 int vprintk(const char *fmt, va_list args);
167 
168 asmlinkage __printf(1, 2) __cold
169 int printk(const char *fmt, ...);
170 
171 /*
172  * Special printk facility for scheduler/timekeeping use only, _DO_NOT_USE_ !
173  */
174 __printf(1, 2) __cold int printk_deferred(const char *fmt, ...);
175 
176 /*
177  * Please don't use printk_ratelimit(), because it shares ratelimiting state
178  * with all other unrelated printk_ratelimit() callsites.  Instead use
179  * printk_ratelimited() or plain old __ratelimit().
180  */
181 extern int __printk_ratelimit(const char *func);
182 #define printk_ratelimit() __printk_ratelimit(__func__)
183 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
184 				   unsigned int interval_msec);
185 
186 extern int printk_delay_msec;
187 extern int dmesg_restrict;
188 
189 extern int
190 devkmsg_sysctl_set_loglvl(struct ctl_table *table, int write, void __user *buf,
191 			  size_t *lenp, loff_t *ppos);
192 
193 extern void wake_up_klogd(void);
194 
195 char *log_buf_addr_get(void);
196 u32 log_buf_len_get(void);
197 void log_buf_vmcoreinfo_setup(void);
198 void __init setup_log_buf(int early);
199 __printf(1, 2) void dump_stack_set_arch_desc(const char *fmt, ...);
200 void dump_stack_print_info(const char *log_lvl);
201 void show_regs_print_info(const char *log_lvl);
202 extern asmlinkage void dump_stack(void) __cold;
203 extern void printk_safe_init(void);
204 extern void printk_safe_flush(void);
205 extern void printk_safe_flush_on_panic(void);
206 #else
207 static inline __printf(1, 0)
208 int vprintk(const char *s, va_list args)
209 {
210 	return 0;
211 }
212 static inline __printf(1, 2) __cold
213 int printk(const char *s, ...)
214 {
215 	return 0;
216 }
217 static inline __printf(1, 2) __cold
218 int printk_deferred(const char *s, ...)
219 {
220 	return 0;
221 }
222 static inline int printk_ratelimit(void)
223 {
224 	return 0;
225 }
226 static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies,
227 					  unsigned int interval_msec)
228 {
229 	return false;
230 }
231 
232 static inline void wake_up_klogd(void)
233 {
234 }
235 
236 static inline char *log_buf_addr_get(void)
237 {
238 	return NULL;
239 }
240 
241 static inline u32 log_buf_len_get(void)
242 {
243 	return 0;
244 }
245 
246 static inline void log_buf_vmcoreinfo_setup(void)
247 {
248 }
249 
250 static inline void setup_log_buf(int early)
251 {
252 }
253 
254 static inline __printf(1, 2) void dump_stack_set_arch_desc(const char *fmt, ...)
255 {
256 }
257 
258 static inline void dump_stack_print_info(const char *log_lvl)
259 {
260 }
261 
262 static inline void show_regs_print_info(const char *log_lvl)
263 {
264 }
265 
266 static inline void dump_stack(void)
267 {
268 }
269 
270 static inline void printk_safe_init(void)
271 {
272 }
273 
274 static inline void printk_safe_flush(void)
275 {
276 }
277 
278 static inline void printk_safe_flush_on_panic(void)
279 {
280 }
281 #endif
282 
283 extern int kptr_restrict;
284 
285 #ifndef pr_fmt
286 #define pr_fmt(fmt) fmt
287 #endif
288 
289 /*
290  * These can be used to print at the various log levels.
291  * All of these will print unconditionally, although note that pr_debug()
292  * and other debug macros are compiled out unless either DEBUG is defined
293  * or CONFIG_DYNAMIC_DEBUG is set.
294  */
295 #define pr_emerg(fmt, ...) \
296 	printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
297 #define pr_alert(fmt, ...) \
298 	printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
299 #define pr_crit(fmt, ...) \
300 	printk(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
301 #define pr_err(fmt, ...) \
302 	printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
303 #define pr_warning(fmt, ...) \
304 	printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
305 #define pr_warn pr_warning
306 #define pr_notice(fmt, ...) \
307 	printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
308 #define pr_info(fmt, ...) \
309 	printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
310 /*
311  * Like KERN_CONT, pr_cont() should only be used when continuing
312  * a line with no newline ('\n') enclosed. Otherwise it defaults
313  * back to KERN_DEFAULT.
314  */
315 #define pr_cont(fmt, ...) \
316 	printk(KERN_CONT fmt, ##__VA_ARGS__)
317 
318 /* pr_devel() should produce zero code unless DEBUG is defined */
319 #ifdef DEBUG
320 #define pr_devel(fmt, ...) \
321 	printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
322 #else
323 #define pr_devel(fmt, ...) \
324 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
325 #endif
326 
327 
328 /* If you are writing a driver, please use dev_dbg instead */
329 #if defined(CONFIG_DYNAMIC_DEBUG)
330 #include <linux/dynamic_debug.h>
331 
332 /* dynamic_pr_debug() uses pr_fmt() internally so we don't need it here */
333 #define pr_debug(fmt, ...) \
334 	dynamic_pr_debug(fmt, ##__VA_ARGS__)
335 #elif defined(DEBUG)
336 #define pr_debug(fmt, ...) \
337 	printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
338 #else
339 #define pr_debug(fmt, ...) \
340 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
341 #endif
342 
343 /*
344  * Print a one-time message (analogous to WARN_ONCE() et al):
345  */
346 
347 #ifdef CONFIG_PRINTK
348 #define printk_once(fmt, ...)					\
349 ({								\
350 	static bool __print_once __read_mostly;			\
351 	bool __ret_print_once = !__print_once;			\
352 								\
353 	if (!__print_once) {					\
354 		__print_once = true;				\
355 		printk(fmt, ##__VA_ARGS__);			\
356 	}							\
357 	unlikely(__ret_print_once);				\
358 })
359 #define printk_deferred_once(fmt, ...)				\
360 ({								\
361 	static bool __print_once __read_mostly;			\
362 	bool __ret_print_once = !__print_once;			\
363 								\
364 	if (!__print_once) {					\
365 		__print_once = true;				\
366 		printk_deferred(fmt, ##__VA_ARGS__);		\
367 	}							\
368 	unlikely(__ret_print_once);				\
369 })
370 #else
371 #define printk_once(fmt, ...)					\
372 	no_printk(fmt, ##__VA_ARGS__)
373 #define printk_deferred_once(fmt, ...)				\
374 	no_printk(fmt, ##__VA_ARGS__)
375 #endif
376 
377 #define pr_emerg_once(fmt, ...)					\
378 	printk_once(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
379 #define pr_alert_once(fmt, ...)					\
380 	printk_once(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
381 #define pr_crit_once(fmt, ...)					\
382 	printk_once(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
383 #define pr_err_once(fmt, ...)					\
384 	printk_once(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
385 #define pr_warn_once(fmt, ...)					\
386 	printk_once(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
387 #define pr_notice_once(fmt, ...)				\
388 	printk_once(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
389 #define pr_info_once(fmt, ...)					\
390 	printk_once(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
391 #define pr_cont_once(fmt, ...)					\
392 	printk_once(KERN_CONT pr_fmt(fmt), ##__VA_ARGS__)
393 
394 #if defined(DEBUG)
395 #define pr_devel_once(fmt, ...)					\
396 	printk_once(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
397 #else
398 #define pr_devel_once(fmt, ...)					\
399 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
400 #endif
401 
402 /* If you are writing a driver, please use dev_dbg instead */
403 #if defined(DEBUG)
404 #define pr_debug_once(fmt, ...)					\
405 	printk_once(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
406 #else
407 #define pr_debug_once(fmt, ...)					\
408 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
409 #endif
410 
411 /*
412  * ratelimited messages with local ratelimit_state,
413  * no local ratelimit_state used in the !PRINTK case
414  */
415 #ifdef CONFIG_PRINTK
416 #define printk_ratelimited(fmt, ...)					\
417 ({									\
418 	static DEFINE_RATELIMIT_STATE(_rs,				\
419 				      DEFAULT_RATELIMIT_INTERVAL,	\
420 				      DEFAULT_RATELIMIT_BURST);		\
421 									\
422 	if (__ratelimit(&_rs))						\
423 		printk(fmt, ##__VA_ARGS__);				\
424 })
425 #else
426 #define printk_ratelimited(fmt, ...)					\
427 	no_printk(fmt, ##__VA_ARGS__)
428 #endif
429 
430 #define pr_emerg_ratelimited(fmt, ...)					\
431 	printk_ratelimited(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
432 #define pr_alert_ratelimited(fmt, ...)					\
433 	printk_ratelimited(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
434 #define pr_crit_ratelimited(fmt, ...)					\
435 	printk_ratelimited(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
436 #define pr_err_ratelimited(fmt, ...)					\
437 	printk_ratelimited(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
438 #define pr_warn_ratelimited(fmt, ...)					\
439 	printk_ratelimited(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
440 #define pr_notice_ratelimited(fmt, ...)					\
441 	printk_ratelimited(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
442 #define pr_info_ratelimited(fmt, ...)					\
443 	printk_ratelimited(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
444 /* no pr_cont_ratelimited, don't do that... */
445 
446 #if defined(DEBUG)
447 #define pr_devel_ratelimited(fmt, ...)					\
448 	printk_ratelimited(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
449 #else
450 #define pr_devel_ratelimited(fmt, ...)					\
451 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
452 #endif
453 
454 /* If you are writing a driver, please use dev_dbg instead */
455 #if defined(CONFIG_DYNAMIC_DEBUG)
456 /* descriptor check is first to prevent flooding with "callbacks suppressed" */
457 #define pr_debug_ratelimited(fmt, ...)					\
458 do {									\
459 	static DEFINE_RATELIMIT_STATE(_rs,				\
460 				      DEFAULT_RATELIMIT_INTERVAL,	\
461 				      DEFAULT_RATELIMIT_BURST);		\
462 	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, pr_fmt(fmt));		\
463 	if (DYNAMIC_DEBUG_BRANCH(descriptor) &&				\
464 	    __ratelimit(&_rs))						\
465 		__dynamic_pr_debug(&descriptor, pr_fmt(fmt), ##__VA_ARGS__);	\
466 } while (0)
467 #elif defined(DEBUG)
468 #define pr_debug_ratelimited(fmt, ...)					\
469 	printk_ratelimited(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
470 #else
471 #define pr_debug_ratelimited(fmt, ...) \
472 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
473 #endif
474 
475 extern const struct file_operations kmsg_fops;
476 
477 enum {
478 	DUMP_PREFIX_NONE,
479 	DUMP_PREFIX_ADDRESS,
480 	DUMP_PREFIX_OFFSET
481 };
482 extern int hex_dump_to_buffer(const void *buf, size_t len, int rowsize,
483 			      int groupsize, char *linebuf, size_t linebuflen,
484 			      bool ascii);
485 #ifdef CONFIG_PRINTK
486 extern void print_hex_dump(const char *level, const char *prefix_str,
487 			   int prefix_type, int rowsize, int groupsize,
488 			   const void *buf, size_t len, bool ascii);
489 #if defined(CONFIG_DYNAMIC_DEBUG)
490 #define print_hex_dump_bytes(prefix_str, prefix_type, buf, len)	\
491 	dynamic_hex_dump(prefix_str, prefix_type, 16, 1, buf, len, true)
492 #else
493 extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
494 				 const void *buf, size_t len);
495 #endif /* defined(CONFIG_DYNAMIC_DEBUG) */
496 #else
497 static inline void print_hex_dump(const char *level, const char *prefix_str,
498 				  int prefix_type, int rowsize, int groupsize,
499 				  const void *buf, size_t len, bool ascii)
500 {
501 }
502 static inline void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
503 					const void *buf, size_t len)
504 {
505 }
506 
507 #endif
508 
509 #if defined(CONFIG_DYNAMIC_DEBUG)
510 #define print_hex_dump_debug(prefix_str, prefix_type, rowsize,	\
511 			     groupsize, buf, len, ascii)	\
512 	dynamic_hex_dump(prefix_str, prefix_type, rowsize,	\
513 			 groupsize, buf, len, ascii)
514 #elif defined(DEBUG)
515 #define print_hex_dump_debug(prefix_str, prefix_type, rowsize,		\
516 			     groupsize, buf, len, ascii)		\
517 	print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, rowsize,	\
518 		       groupsize, buf, len, ascii)
519 #else
520 static inline void print_hex_dump_debug(const char *prefix_str, int prefix_type,
521 					int rowsize, int groupsize,
522 					const void *buf, size_t len, bool ascii)
523 {
524 }
525 #endif
526 
527 #endif
528