xref: /linux-6.15/include/linux/printk.h (revision e00a844a)
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 'd':	/* KERN_DEFAULT */
22 		case 'c':	/* KERN_CONT */
23 			return buffer[1];
24 		}
25 	}
26 	return 0;
27 }
28 
29 static inline const char *printk_skip_level(const char *buffer)
30 {
31 	if (printk_get_level(buffer))
32 		return buffer + 2;
33 
34 	return buffer;
35 }
36 
37 static inline const char *printk_skip_headers(const char *buffer)
38 {
39 	while (printk_get_level(buffer))
40 		buffer = printk_skip_level(buffer);
41 
42 	return buffer;
43 }
44 
45 #define CONSOLE_EXT_LOG_MAX	8192
46 
47 /* printk's without a loglevel use this.. */
48 #define MESSAGE_LOGLEVEL_DEFAULT CONFIG_MESSAGE_LOGLEVEL_DEFAULT
49 
50 /* We show everything that is MORE important than this.. */
51 #define CONSOLE_LOGLEVEL_SILENT  0 /* Mum's the word */
52 #define CONSOLE_LOGLEVEL_MIN	 1 /* Minimum loglevel we let people use */
53 #define CONSOLE_LOGLEVEL_QUIET	 4 /* Shhh ..., when booted with "quiet" */
54 #define CONSOLE_LOGLEVEL_DEBUG	10 /* issue debug messages */
55 #define CONSOLE_LOGLEVEL_MOTORMOUTH 15	/* You can't shut this one up */
56 
57 /*
58  * Default used to be hard-coded at 7, we're now allowing it to be set from
59  * kernel config.
60  */
61 #define CONSOLE_LOGLEVEL_DEFAULT CONFIG_CONSOLE_LOGLEVEL_DEFAULT
62 
63 extern int console_printk[];
64 
65 #define console_loglevel (console_printk[0])
66 #define default_message_loglevel (console_printk[1])
67 #define minimum_console_loglevel (console_printk[2])
68 #define default_console_loglevel (console_printk[3])
69 
70 static inline void console_silent(void)
71 {
72 	console_loglevel = CONSOLE_LOGLEVEL_SILENT;
73 }
74 
75 static inline void console_verbose(void)
76 {
77 	if (console_loglevel)
78 		console_loglevel = CONSOLE_LOGLEVEL_MOTORMOUTH;
79 }
80 
81 /* strlen("ratelimit") + 1 */
82 #define DEVKMSG_STR_MAX_SIZE 10
83 extern char devkmsg_log_str[];
84 struct ctl_table;
85 
86 struct va_format {
87 	const char *fmt;
88 	va_list *va;
89 };
90 
91 /*
92  * FW_BUG
93  * Add this to a message where you are sure the firmware is buggy or behaves
94  * really stupid or out of spec. Be aware that the responsible BIOS developer
95  * should be able to fix this issue or at least get a concrete idea of the
96  * problem by reading your message without the need of looking at the kernel
97  * code.
98  *
99  * Use it for definite and high priority BIOS bugs.
100  *
101  * FW_WARN
102  * Use it for not that clear (e.g. could the kernel messed up things already?)
103  * and medium priority BIOS bugs.
104  *
105  * FW_INFO
106  * Use this one if you want to tell the user or vendor about something
107  * suspicious, but generally harmless related to the firmware.
108  *
109  * Use it for information or very low priority BIOS bugs.
110  */
111 #define FW_BUG		"[Firmware Bug]: "
112 #define FW_WARN		"[Firmware Warn]: "
113 #define FW_INFO		"[Firmware Info]: "
114 
115 /*
116  * HW_ERR
117  * Add this to a message for hardware errors, so that user can report
118  * it to hardware vendor instead of LKML or software vendor.
119  */
120 #define HW_ERR		"[Hardware Error]: "
121 
122 /*
123  * DEPRECATED
124  * Add this to a message whenever you want to warn user space about the use
125  * of a deprecated aspect of an API so they can stop using it
126  */
127 #define DEPRECATED	"[Deprecated]: "
128 
129 /*
130  * Dummy printk for disabled debugging statements to use whilst maintaining
131  * gcc's format checking.
132  */
133 #define no_printk(fmt, ...)				\
134 ({							\
135 	if (0)						\
136 		printk(fmt, ##__VA_ARGS__);		\
137 	0;						\
138 })
139 
140 #ifdef CONFIG_EARLY_PRINTK
141 extern asmlinkage __printf(1, 2)
142 void early_printk(const char *fmt, ...);
143 #else
144 static inline __printf(1, 2) __cold
145 void early_printk(const char *s, ...) { }
146 #endif
147 
148 #ifdef CONFIG_PRINTK_NMI
149 extern void printk_nmi_enter(void);
150 extern void printk_nmi_exit(void);
151 #else
152 static inline void printk_nmi_enter(void) { }
153 static inline void printk_nmi_exit(void) { }
154 #endif /* PRINTK_NMI */
155 
156 #ifdef CONFIG_PRINTK
157 asmlinkage __printf(5, 0)
158 int vprintk_emit(int facility, int level,
159 		 const char *dict, size_t dictlen,
160 		 const char *fmt, va_list args);
161 
162 asmlinkage __printf(1, 0)
163 int vprintk(const char *fmt, va_list args);
164 
165 asmlinkage __printf(5, 6) __cold
166 int printk_emit(int facility, int level,
167 		const char *dict, size_t dictlen,
168 		const char *fmt, ...);
169 
170 asmlinkage __printf(1, 2) __cold
171 int printk(const char *fmt, ...);
172 
173 /*
174  * Special printk facility for scheduler/timekeeping use only, _DO_NOT_USE_ !
175  */
176 __printf(1, 2) __cold int printk_deferred(const char *fmt, ...);
177 
178 /*
179  * Please don't use printk_ratelimit(), because it shares ratelimiting state
180  * with all other unrelated printk_ratelimit() callsites.  Instead use
181  * printk_ratelimited() or plain old __ratelimit().
182  */
183 extern int __printk_ratelimit(const char *func);
184 #define printk_ratelimit() __printk_ratelimit(__func__)
185 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
186 				   unsigned int interval_msec);
187 
188 extern int printk_delay_msec;
189 extern int dmesg_restrict;
190 
191 extern int
192 devkmsg_sysctl_set_loglvl(struct ctl_table *table, int write, void __user *buf,
193 			  size_t *lenp, loff_t *ppos);
194 
195 extern void wake_up_klogd(void);
196 
197 char *log_buf_addr_get(void);
198 u32 log_buf_len_get(void);
199 void log_buf_vmcoreinfo_setup(void);
200 void __init setup_log_buf(int early);
201 __printf(1, 2) void dump_stack_set_arch_desc(const char *fmt, ...);
202 void dump_stack_print_info(const char *log_lvl);
203 void show_regs_print_info(const char *log_lvl);
204 extern void printk_safe_init(void);
205 extern void printk_safe_flush(void);
206 extern void printk_safe_flush_on_panic(void);
207 #else
208 static inline __printf(1, 0)
209 int vprintk(const char *s, va_list args)
210 {
211 	return 0;
212 }
213 static inline __printf(1, 2) __cold
214 int printk(const char *s, ...)
215 {
216 	return 0;
217 }
218 static inline __printf(1, 2) __cold
219 int printk_deferred(const char *s, ...)
220 {
221 	return 0;
222 }
223 static inline int printk_ratelimit(void)
224 {
225 	return 0;
226 }
227 static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies,
228 					  unsigned int interval_msec)
229 {
230 	return false;
231 }
232 
233 static inline void wake_up_klogd(void)
234 {
235 }
236 
237 static inline char *log_buf_addr_get(void)
238 {
239 	return NULL;
240 }
241 
242 static inline u32 log_buf_len_get(void)
243 {
244 	return 0;
245 }
246 
247 static inline void log_buf_vmcoreinfo_setup(void)
248 {
249 }
250 
251 static inline void setup_log_buf(int early)
252 {
253 }
254 
255 static inline __printf(1, 2) void dump_stack_set_arch_desc(const char *fmt, ...)
256 {
257 }
258 
259 static inline void dump_stack_print_info(const char *log_lvl)
260 {
261 }
262 
263 static inline void show_regs_print_info(const char *log_lvl)
264 {
265 }
266 
267 static inline void printk_safe_init(void)
268 {
269 }
270 
271 static inline void printk_safe_flush(void)
272 {
273 }
274 
275 static inline void printk_safe_flush_on_panic(void)
276 {
277 }
278 #endif
279 
280 extern int kptr_restrict;
281 
282 extern asmlinkage void dump_stack(void) __cold;
283 
284 #ifndef pr_fmt
285 #define pr_fmt(fmt) fmt
286 #endif
287 
288 /*
289  * These can be used to print at the various log levels.
290  * All of these will print unconditionally, although note that pr_debug()
291  * and other debug macros are compiled out unless either DEBUG is defined
292  * or CONFIG_DYNAMIC_DEBUG is set.
293  */
294 #define pr_emerg(fmt, ...) \
295 	printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
296 #define pr_alert(fmt, ...) \
297 	printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
298 #define pr_crit(fmt, ...) \
299 	printk(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
300 #define pr_err(fmt, ...) \
301 	printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
302 #define pr_warning(fmt, ...) \
303 	printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
304 #define pr_warn pr_warning
305 #define pr_notice(fmt, ...) \
306 	printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
307 #define pr_info(fmt, ...) \
308 	printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
309 /*
310  * Like KERN_CONT, pr_cont() should only be used when continuing
311  * a line with no newline ('\n') enclosed. Otherwise it defaults
312  * back to KERN_DEFAULT.
313  */
314 #define pr_cont(fmt, ...) \
315 	printk(KERN_CONT fmt, ##__VA_ARGS__)
316 
317 /* pr_devel() should produce zero code unless DEBUG is defined */
318 #ifdef DEBUG
319 #define pr_devel(fmt, ...) \
320 	printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
321 #else
322 #define pr_devel(fmt, ...) \
323 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
324 #endif
325 
326 
327 /* If you are writing a driver, please use dev_dbg instead */
328 #if defined(CONFIG_DYNAMIC_DEBUG)
329 #include <linux/dynamic_debug.h>
330 
331 /* dynamic_pr_debug() uses pr_fmt() internally so we don't need it here */
332 #define pr_debug(fmt, ...) \
333 	dynamic_pr_debug(fmt, ##__VA_ARGS__)
334 #elif defined(DEBUG)
335 #define pr_debug(fmt, ...) \
336 	printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
337 #else
338 #define pr_debug(fmt, ...) \
339 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
340 #endif
341 
342 /*
343  * Print a one-time message (analogous to WARN_ONCE() et al):
344  */
345 
346 #ifdef CONFIG_PRINTK
347 #define printk_once(fmt, ...)					\
348 ({								\
349 	static bool __print_once __read_mostly;			\
350 	bool __ret_print_once = !__print_once;			\
351 								\
352 	if (!__print_once) {					\
353 		__print_once = true;				\
354 		printk(fmt, ##__VA_ARGS__);			\
355 	}							\
356 	unlikely(__ret_print_once);				\
357 })
358 #define printk_deferred_once(fmt, ...)				\
359 ({								\
360 	static bool __print_once __read_mostly;			\
361 	bool __ret_print_once = !__print_once;			\
362 								\
363 	if (!__print_once) {					\
364 		__print_once = true;				\
365 		printk_deferred(fmt, ##__VA_ARGS__);		\
366 	}							\
367 	unlikely(__ret_print_once);				\
368 })
369 #else
370 #define printk_once(fmt, ...)					\
371 	no_printk(fmt, ##__VA_ARGS__)
372 #define printk_deferred_once(fmt, ...)				\
373 	no_printk(fmt, ##__VA_ARGS__)
374 #endif
375 
376 #define pr_emerg_once(fmt, ...)					\
377 	printk_once(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
378 #define pr_alert_once(fmt, ...)					\
379 	printk_once(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
380 #define pr_crit_once(fmt, ...)					\
381 	printk_once(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
382 #define pr_err_once(fmt, ...)					\
383 	printk_once(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
384 #define pr_warn_once(fmt, ...)					\
385 	printk_once(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
386 #define pr_notice_once(fmt, ...)				\
387 	printk_once(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
388 #define pr_info_once(fmt, ...)					\
389 	printk_once(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
390 #define pr_cont_once(fmt, ...)					\
391 	printk_once(KERN_CONT pr_fmt(fmt), ##__VA_ARGS__)
392 
393 #if defined(DEBUG)
394 #define pr_devel_once(fmt, ...)					\
395 	printk_once(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
396 #else
397 #define pr_devel_once(fmt, ...)					\
398 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
399 #endif
400 
401 /* If you are writing a driver, please use dev_dbg instead */
402 #if defined(DEBUG)
403 #define pr_debug_once(fmt, ...)					\
404 	printk_once(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
405 #else
406 #define pr_debug_once(fmt, ...)					\
407 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
408 #endif
409 
410 /*
411  * ratelimited messages with local ratelimit_state,
412  * no local ratelimit_state used in the !PRINTK case
413  */
414 #ifdef CONFIG_PRINTK
415 #define printk_ratelimited(fmt, ...)					\
416 ({									\
417 	static DEFINE_RATELIMIT_STATE(_rs,				\
418 				      DEFAULT_RATELIMIT_INTERVAL,	\
419 				      DEFAULT_RATELIMIT_BURST);		\
420 									\
421 	if (__ratelimit(&_rs))						\
422 		printk(fmt, ##__VA_ARGS__);				\
423 })
424 #else
425 #define printk_ratelimited(fmt, ...)					\
426 	no_printk(fmt, ##__VA_ARGS__)
427 #endif
428 
429 #define pr_emerg_ratelimited(fmt, ...)					\
430 	printk_ratelimited(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
431 #define pr_alert_ratelimited(fmt, ...)					\
432 	printk_ratelimited(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
433 #define pr_crit_ratelimited(fmt, ...)					\
434 	printk_ratelimited(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
435 #define pr_err_ratelimited(fmt, ...)					\
436 	printk_ratelimited(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
437 #define pr_warn_ratelimited(fmt, ...)					\
438 	printk_ratelimited(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
439 #define pr_notice_ratelimited(fmt, ...)					\
440 	printk_ratelimited(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
441 #define pr_info_ratelimited(fmt, ...)					\
442 	printk_ratelimited(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
443 /* no pr_cont_ratelimited, don't do that... */
444 
445 #if defined(DEBUG)
446 #define pr_devel_ratelimited(fmt, ...)					\
447 	printk_ratelimited(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
448 #else
449 #define pr_devel_ratelimited(fmt, ...)					\
450 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
451 #endif
452 
453 /* If you are writing a driver, please use dev_dbg instead */
454 #if defined(CONFIG_DYNAMIC_DEBUG)
455 /* descriptor check is first to prevent flooding with "callbacks suppressed" */
456 #define pr_debug_ratelimited(fmt, ...)					\
457 do {									\
458 	static DEFINE_RATELIMIT_STATE(_rs,				\
459 				      DEFAULT_RATELIMIT_INTERVAL,	\
460 				      DEFAULT_RATELIMIT_BURST);		\
461 	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, pr_fmt(fmt));		\
462 	if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT) &&	\
463 	    __ratelimit(&_rs))						\
464 		__dynamic_pr_debug(&descriptor, pr_fmt(fmt), ##__VA_ARGS__);	\
465 } while (0)
466 #elif defined(DEBUG)
467 #define pr_debug_ratelimited(fmt, ...)					\
468 	printk_ratelimited(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
469 #else
470 #define pr_debug_ratelimited(fmt, ...) \
471 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
472 #endif
473 
474 extern const struct file_operations kmsg_fops;
475 
476 enum {
477 	DUMP_PREFIX_NONE,
478 	DUMP_PREFIX_ADDRESS,
479 	DUMP_PREFIX_OFFSET
480 };
481 extern int hex_dump_to_buffer(const void *buf, size_t len, int rowsize,
482 			      int groupsize, char *linebuf, size_t linebuflen,
483 			      bool ascii);
484 #ifdef CONFIG_PRINTK
485 extern void print_hex_dump(const char *level, const char *prefix_str,
486 			   int prefix_type, int rowsize, int groupsize,
487 			   const void *buf, size_t len, bool ascii);
488 #if defined(CONFIG_DYNAMIC_DEBUG)
489 #define print_hex_dump_bytes(prefix_str, prefix_type, buf, len)	\
490 	dynamic_hex_dump(prefix_str, prefix_type, 16, 1, buf, len, true)
491 #else
492 extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
493 				 const void *buf, size_t len);
494 #endif /* defined(CONFIG_DYNAMIC_DEBUG) */
495 #else
496 static inline void print_hex_dump(const char *level, const char *prefix_str,
497 				  int prefix_type, int rowsize, int groupsize,
498 				  const void *buf, size_t len, bool ascii)
499 {
500 }
501 static inline void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
502 					const void *buf, size_t len)
503 {
504 }
505 
506 #endif
507 
508 #if defined(CONFIG_DYNAMIC_DEBUG)
509 #define print_hex_dump_debug(prefix_str, prefix_type, rowsize,	\
510 			     groupsize, buf, len, ascii)	\
511 	dynamic_hex_dump(prefix_str, prefix_type, rowsize,	\
512 			 groupsize, buf, len, ascii)
513 #elif defined(DEBUG)
514 #define print_hex_dump_debug(prefix_str, prefix_type, rowsize,		\
515 			     groupsize, buf, len, ascii)		\
516 	print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, rowsize,	\
517 		       groupsize, buf, len, ascii)
518 #else
519 static inline void print_hex_dump_debug(const char *prefix_str, int prefix_type,
520 					int rowsize, int groupsize,
521 					const void *buf, size_t len, bool ascii)
522 {
523 }
524 #endif
525 
526 #endif
527