xref: /linux-6.15/include/linux/printk.h (revision bb970707)
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 static inline int printk_get_level(const char *buffer)
14 {
15 	if (buffer[0] == KERN_SOH_ASCII && buffer[1]) {
16 		switch (buffer[1]) {
17 		case '0' ... '7':
18 		case 'd':	/* KERN_DEFAULT */
19 			return buffer[1];
20 		}
21 	}
22 	return 0;
23 }
24 
25 static inline const char *printk_skip_level(const char *buffer)
26 {
27 	if (printk_get_level(buffer))
28 		return buffer + 2;
29 
30 	return buffer;
31 }
32 
33 #define CONSOLE_EXT_LOG_MAX	8192
34 
35 /* printk's without a loglevel use this.. */
36 #define MESSAGE_LOGLEVEL_DEFAULT CONFIG_MESSAGE_LOGLEVEL_DEFAULT
37 
38 /* We show everything that is MORE important than this.. */
39 #define CONSOLE_LOGLEVEL_SILENT  0 /* Mum's the word */
40 #define CONSOLE_LOGLEVEL_MIN	 1 /* Minimum loglevel we let people use */
41 #define CONSOLE_LOGLEVEL_QUIET	 4 /* Shhh ..., when booted with "quiet" */
42 #define CONSOLE_LOGLEVEL_DEFAULT 7 /* anything MORE serious than KERN_DEBUG */
43 #define CONSOLE_LOGLEVEL_DEBUG	10 /* issue debug messages */
44 #define CONSOLE_LOGLEVEL_MOTORMOUTH 15	/* You can't shut this one up */
45 
46 extern int console_printk[];
47 
48 #define console_loglevel (console_printk[0])
49 #define default_message_loglevel (console_printk[1])
50 #define minimum_console_loglevel (console_printk[2])
51 #define default_console_loglevel (console_printk[3])
52 
53 static inline void console_silent(void)
54 {
55 	console_loglevel = CONSOLE_LOGLEVEL_SILENT;
56 }
57 
58 static inline void console_verbose(void)
59 {
60 	if (console_loglevel)
61 		console_loglevel = CONSOLE_LOGLEVEL_MOTORMOUTH;
62 }
63 
64 struct va_format {
65 	const char *fmt;
66 	va_list *va;
67 };
68 
69 /*
70  * FW_BUG
71  * Add this to a message where you are sure the firmware is buggy or behaves
72  * really stupid or out of spec. Be aware that the responsible BIOS developer
73  * should be able to fix this issue or at least get a concrete idea of the
74  * problem by reading your message without the need of looking at the kernel
75  * code.
76  *
77  * Use it for definite and high priority BIOS bugs.
78  *
79  * FW_WARN
80  * Use it for not that clear (e.g. could the kernel messed up things already?)
81  * and medium priority BIOS bugs.
82  *
83  * FW_INFO
84  * Use this one if you want to tell the user or vendor about something
85  * suspicious, but generally harmless related to the firmware.
86  *
87  * Use it for information or very low priority BIOS bugs.
88  */
89 #define FW_BUG		"[Firmware Bug]: "
90 #define FW_WARN		"[Firmware Warn]: "
91 #define FW_INFO		"[Firmware Info]: "
92 
93 /*
94  * HW_ERR
95  * Add this to a message for hardware errors, so that user can report
96  * it to hardware vendor instead of LKML or software vendor.
97  */
98 #define HW_ERR		"[Hardware Error]: "
99 
100 /*
101  * DEPRECATED
102  * Add this to a message whenever you want to warn user space about the use
103  * of a deprecated aspect of an API so they can stop using it
104  */
105 #define DEPRECATED	"[Deprecated]: "
106 
107 /*
108  * Dummy printk for disabled debugging statements to use whilst maintaining
109  * gcc's format checking.
110  */
111 #define no_printk(fmt, ...)			\
112 do {						\
113 	if (0)					\
114 		printk(fmt, ##__VA_ARGS__);	\
115 } while (0)
116 
117 #ifdef CONFIG_EARLY_PRINTK
118 extern asmlinkage __printf(1, 2)
119 void early_printk(const char *fmt, ...);
120 #else
121 static inline __printf(1, 2) __cold
122 void early_printk(const char *s, ...) { }
123 #endif
124 
125 #ifdef CONFIG_PRINTK_NMI
126 extern void printk_nmi_init(void);
127 extern void printk_nmi_enter(void);
128 extern void printk_nmi_exit(void);
129 extern void printk_nmi_flush(void);
130 extern void printk_nmi_flush_on_panic(void);
131 #else
132 static inline void printk_nmi_init(void) { }
133 static inline void printk_nmi_enter(void) { }
134 static inline void printk_nmi_exit(void) { }
135 static inline void printk_nmi_flush(void) { }
136 static inline void printk_nmi_flush_on_panic(void) { }
137 #endif /* PRINTK_NMI */
138 
139 #ifdef CONFIG_PRINTK
140 asmlinkage __printf(5, 0)
141 int vprintk_emit(int facility, int level,
142 		 const char *dict, size_t dictlen,
143 		 const char *fmt, va_list args);
144 
145 asmlinkage __printf(1, 0)
146 int vprintk(const char *fmt, va_list args);
147 
148 asmlinkage __printf(5, 6) __cold
149 int printk_emit(int facility, int level,
150 		const char *dict, size_t dictlen,
151 		const char *fmt, ...);
152 
153 asmlinkage __printf(1, 2) __cold
154 int printk(const char *fmt, ...);
155 
156 /*
157  * Special printk facility for scheduler/timekeeping use only, _DO_NOT_USE_ !
158  */
159 __printf(1, 2) __cold int printk_deferred(const char *fmt, ...);
160 
161 /*
162  * Please don't use printk_ratelimit(), because it shares ratelimiting state
163  * with all other unrelated printk_ratelimit() callsites.  Instead use
164  * printk_ratelimited() or plain old __ratelimit().
165  */
166 extern int __printk_ratelimit(const char *func);
167 #define printk_ratelimit() __printk_ratelimit(__func__)
168 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
169 				   unsigned int interval_msec);
170 
171 extern int printk_delay_msec;
172 extern int dmesg_restrict;
173 extern int kptr_restrict;
174 
175 extern void wake_up_klogd(void);
176 
177 char *log_buf_addr_get(void);
178 u32 log_buf_len_get(void);
179 void log_buf_kexec_setup(void);
180 void __init setup_log_buf(int early);
181 __printf(1, 2) void dump_stack_set_arch_desc(const char *fmt, ...);
182 void dump_stack_print_info(const char *log_lvl);
183 void show_regs_print_info(const char *log_lvl);
184 #else
185 static inline __printf(1, 0)
186 int vprintk(const char *s, va_list args)
187 {
188 	return 0;
189 }
190 static inline __printf(1, 2) __cold
191 int printk(const char *s, ...)
192 {
193 	return 0;
194 }
195 static inline __printf(1, 2) __cold
196 int printk_deferred(const char *s, ...)
197 {
198 	return 0;
199 }
200 static inline int printk_ratelimit(void)
201 {
202 	return 0;
203 }
204 static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies,
205 					  unsigned int interval_msec)
206 {
207 	return false;
208 }
209 
210 static inline void wake_up_klogd(void)
211 {
212 }
213 
214 static inline char *log_buf_addr_get(void)
215 {
216 	return NULL;
217 }
218 
219 static inline u32 log_buf_len_get(void)
220 {
221 	return 0;
222 }
223 
224 static inline void log_buf_kexec_setup(void)
225 {
226 }
227 
228 static inline void setup_log_buf(int early)
229 {
230 }
231 
232 static inline __printf(1, 2) void dump_stack_set_arch_desc(const char *fmt, ...)
233 {
234 }
235 
236 static inline void dump_stack_print_info(const char *log_lvl)
237 {
238 }
239 
240 static inline void show_regs_print_info(const char *log_lvl)
241 {
242 }
243 #endif
244 
245 extern asmlinkage void dump_stack(void) __cold;
246 
247 #ifndef pr_fmt
248 #define pr_fmt(fmt) fmt
249 #endif
250 
251 /*
252  * These can be used to print at the various log levels.
253  * All of these will print unconditionally, although note that pr_debug()
254  * and other debug macros are compiled out unless either DEBUG is defined
255  * or CONFIG_DYNAMIC_DEBUG is set.
256  */
257 #define pr_emerg(fmt, ...) \
258 	printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
259 #define pr_alert(fmt, ...) \
260 	printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
261 #define pr_crit(fmt, ...) \
262 	printk(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
263 #define pr_err(fmt, ...) \
264 	printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
265 #define pr_warning(fmt, ...) \
266 	printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
267 #define pr_warn pr_warning
268 #define pr_notice(fmt, ...) \
269 	printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
270 #define pr_info(fmt, ...) \
271 	printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
272 /*
273  * Like KERN_CONT, pr_cont() should only be used when continuing
274  * a line with no newline ('\n') enclosed. Otherwise it defaults
275  * back to KERN_DEFAULT.
276  */
277 #define pr_cont(fmt, ...) \
278 	printk(KERN_CONT fmt, ##__VA_ARGS__)
279 
280 /* pr_devel() should produce zero code unless DEBUG is defined */
281 #ifdef DEBUG
282 #define pr_devel(fmt, ...) \
283 	printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
284 #else
285 #define pr_devel(fmt, ...) \
286 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
287 #endif
288 
289 #include <linux/dynamic_debug.h>
290 
291 /* If you are writing a driver, please use dev_dbg instead */
292 #if defined(CONFIG_DYNAMIC_DEBUG)
293 /* dynamic_pr_debug() uses pr_fmt() internally so we don't need it here */
294 #define pr_debug(fmt, ...) \
295 	dynamic_pr_debug(fmt, ##__VA_ARGS__)
296 #elif defined(DEBUG)
297 #define pr_debug(fmt, ...) \
298 	printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
299 #else
300 #define pr_debug(fmt, ...) \
301 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
302 #endif
303 
304 /*
305  * Print a one-time message (analogous to WARN_ONCE() et al):
306  */
307 
308 #ifdef CONFIG_PRINTK
309 #define printk_once(fmt, ...)					\
310 ({								\
311 	static bool __print_once __read_mostly;			\
312 								\
313 	if (!__print_once) {					\
314 		__print_once = true;				\
315 		printk(fmt, ##__VA_ARGS__);			\
316 	}							\
317 })
318 #define printk_deferred_once(fmt, ...)				\
319 ({								\
320 	static bool __print_once __read_mostly;			\
321 								\
322 	if (!__print_once) {					\
323 		__print_once = true;				\
324 		printk_deferred(fmt, ##__VA_ARGS__);		\
325 	}							\
326 })
327 #else
328 #define printk_once(fmt, ...)					\
329 	no_printk(fmt, ##__VA_ARGS__)
330 #define printk_deferred_once(fmt, ...)				\
331 	no_printk(fmt, ##__VA_ARGS__)
332 #endif
333 
334 #define pr_emerg_once(fmt, ...)					\
335 	printk_once(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
336 #define pr_alert_once(fmt, ...)					\
337 	printk_once(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
338 #define pr_crit_once(fmt, ...)					\
339 	printk_once(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
340 #define pr_err_once(fmt, ...)					\
341 	printk_once(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
342 #define pr_warn_once(fmt, ...)					\
343 	printk_once(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
344 #define pr_notice_once(fmt, ...)				\
345 	printk_once(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
346 #define pr_info_once(fmt, ...)					\
347 	printk_once(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
348 #define pr_cont_once(fmt, ...)					\
349 	printk_once(KERN_CONT pr_fmt(fmt), ##__VA_ARGS__)
350 
351 #if defined(DEBUG)
352 #define pr_devel_once(fmt, ...)					\
353 	printk_once(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
354 #else
355 #define pr_devel_once(fmt, ...)					\
356 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
357 #endif
358 
359 /* If you are writing a driver, please use dev_dbg instead */
360 #if defined(DEBUG)
361 #define pr_debug_once(fmt, ...)					\
362 	printk_once(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
363 #else
364 #define pr_debug_once(fmt, ...)					\
365 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
366 #endif
367 
368 /*
369  * ratelimited messages with local ratelimit_state,
370  * no local ratelimit_state used in the !PRINTK case
371  */
372 #ifdef CONFIG_PRINTK
373 #define printk_ratelimited(fmt, ...)					\
374 ({									\
375 	static DEFINE_RATELIMIT_STATE(_rs,				\
376 				      DEFAULT_RATELIMIT_INTERVAL,	\
377 				      DEFAULT_RATELIMIT_BURST);		\
378 									\
379 	if (__ratelimit(&_rs))						\
380 		printk(fmt, ##__VA_ARGS__);				\
381 })
382 #else
383 #define printk_ratelimited(fmt, ...)					\
384 	no_printk(fmt, ##__VA_ARGS__)
385 #endif
386 
387 #define pr_emerg_ratelimited(fmt, ...)					\
388 	printk_ratelimited(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
389 #define pr_alert_ratelimited(fmt, ...)					\
390 	printk_ratelimited(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
391 #define pr_crit_ratelimited(fmt, ...)					\
392 	printk_ratelimited(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
393 #define pr_err_ratelimited(fmt, ...)					\
394 	printk_ratelimited(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
395 #define pr_warn_ratelimited(fmt, ...)					\
396 	printk_ratelimited(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
397 #define pr_notice_ratelimited(fmt, ...)					\
398 	printk_ratelimited(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
399 #define pr_info_ratelimited(fmt, ...)					\
400 	printk_ratelimited(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
401 /* no pr_cont_ratelimited, don't do that... */
402 
403 #if defined(DEBUG)
404 #define pr_devel_ratelimited(fmt, ...)					\
405 	printk_ratelimited(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
406 #else
407 #define pr_devel_ratelimited(fmt, ...)					\
408 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
409 #endif
410 
411 /* If you are writing a driver, please use dev_dbg instead */
412 #if defined(CONFIG_DYNAMIC_DEBUG)
413 /* descriptor check is first to prevent flooding with "callbacks suppressed" */
414 #define pr_debug_ratelimited(fmt, ...)					\
415 do {									\
416 	static DEFINE_RATELIMIT_STATE(_rs,				\
417 				      DEFAULT_RATELIMIT_INTERVAL,	\
418 				      DEFAULT_RATELIMIT_BURST);		\
419 	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, pr_fmt(fmt));		\
420 	if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT) &&	\
421 	    __ratelimit(&_rs))						\
422 		__dynamic_pr_debug(&descriptor, pr_fmt(fmt), ##__VA_ARGS__);	\
423 } while (0)
424 #elif defined(DEBUG)
425 #define pr_debug_ratelimited(fmt, ...)					\
426 	printk_ratelimited(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
427 #else
428 #define pr_debug_ratelimited(fmt, ...) \
429 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
430 #endif
431 
432 extern const struct file_operations kmsg_fops;
433 
434 enum {
435 	DUMP_PREFIX_NONE,
436 	DUMP_PREFIX_ADDRESS,
437 	DUMP_PREFIX_OFFSET
438 };
439 extern int hex_dump_to_buffer(const void *buf, size_t len, int rowsize,
440 			      int groupsize, char *linebuf, size_t linebuflen,
441 			      bool ascii);
442 #ifdef CONFIG_PRINTK
443 extern void print_hex_dump(const char *level, const char *prefix_str,
444 			   int prefix_type, int rowsize, int groupsize,
445 			   const void *buf, size_t len, bool ascii);
446 #if defined(CONFIG_DYNAMIC_DEBUG)
447 #define print_hex_dump_bytes(prefix_str, prefix_type, buf, len)	\
448 	dynamic_hex_dump(prefix_str, prefix_type, 16, 1, buf, len, true)
449 #else
450 extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
451 				 const void *buf, size_t len);
452 #endif /* defined(CONFIG_DYNAMIC_DEBUG) */
453 #else
454 static inline void print_hex_dump(const char *level, const char *prefix_str,
455 				  int prefix_type, int rowsize, int groupsize,
456 				  const void *buf, size_t len, bool ascii)
457 {
458 }
459 static inline void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
460 					const void *buf, size_t len)
461 {
462 }
463 
464 #endif
465 
466 #if defined(CONFIG_DYNAMIC_DEBUG)
467 #define print_hex_dump_debug(prefix_str, prefix_type, rowsize,	\
468 			     groupsize, buf, len, ascii)	\
469 	dynamic_hex_dump(prefix_str, prefix_type, rowsize,	\
470 			 groupsize, buf, len, ascii)
471 #elif defined(DEBUG)
472 #define print_hex_dump_debug(prefix_str, prefix_type, rowsize,		\
473 			     groupsize, buf, len, ascii)		\
474 	print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, rowsize,	\
475 		       groupsize, buf, len, ascii)
476 #else
477 static inline void print_hex_dump_debug(const char *prefix_str, int prefix_type,
478 					int rowsize, int groupsize,
479 					const void *buf, size_t len, bool ascii)
480 {
481 }
482 #endif
483 
484 #endif
485