xref: /linux-6.15/include/linux/printk.h (revision 6faeeea4)
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 /* printk's without a loglevel use this.. */
34 #define MESSAGE_LOGLEVEL_DEFAULT CONFIG_MESSAGE_LOGLEVEL_DEFAULT
35 
36 /* We show everything that is MORE important than this.. */
37 #define CONSOLE_LOGLEVEL_SILENT  0 /* Mum's the word */
38 #define CONSOLE_LOGLEVEL_MIN	 1 /* Minimum loglevel we let people use */
39 #define CONSOLE_LOGLEVEL_QUIET	 4 /* Shhh ..., when booted with "quiet" */
40 #define CONSOLE_LOGLEVEL_DEFAULT 7 /* anything MORE serious than KERN_DEBUG */
41 #define CONSOLE_LOGLEVEL_DEBUG	10 /* issue debug messages */
42 #define CONSOLE_LOGLEVEL_MOTORMOUTH 15	/* You can't shut this one up */
43 
44 extern int console_printk[];
45 
46 #define console_loglevel (console_printk[0])
47 #define default_message_loglevel (console_printk[1])
48 #define minimum_console_loglevel (console_printk[2])
49 #define default_console_loglevel (console_printk[3])
50 
51 static inline void console_silent(void)
52 {
53 	console_loglevel = CONSOLE_LOGLEVEL_SILENT;
54 }
55 
56 static inline void console_verbose(void)
57 {
58 	if (console_loglevel)
59 		console_loglevel = CONSOLE_LOGLEVEL_MOTORMOUTH;
60 }
61 
62 struct va_format {
63 	const char *fmt;
64 	va_list *va;
65 };
66 
67 /*
68  * FW_BUG
69  * Add this to a message where you are sure the firmware is buggy or behaves
70  * really stupid or out of spec. Be aware that the responsible BIOS developer
71  * should be able to fix this issue or at least get a concrete idea of the
72  * problem by reading your message without the need of looking at the kernel
73  * code.
74  *
75  * Use it for definite and high priority BIOS bugs.
76  *
77  * FW_WARN
78  * Use it for not that clear (e.g. could the kernel messed up things already?)
79  * and medium priority BIOS bugs.
80  *
81  * FW_INFO
82  * Use this one if you want to tell the user or vendor about something
83  * suspicious, but generally harmless related to the firmware.
84  *
85  * Use it for information or very low priority BIOS bugs.
86  */
87 #define FW_BUG		"[Firmware Bug]: "
88 #define FW_WARN		"[Firmware Warn]: "
89 #define FW_INFO		"[Firmware Info]: "
90 
91 /*
92  * HW_ERR
93  * Add this to a message for hardware errors, so that user can report
94  * it to hardware vendor instead of LKML or software vendor.
95  */
96 #define HW_ERR		"[Hardware Error]: "
97 
98 /*
99  * DEPRECATED
100  * Add this to a message whenever you want to warn user space about the use
101  * of a deprecated aspect of an API so they can stop using it
102  */
103 #define DEPRECATED	"[Deprecated]: "
104 
105 /*
106  * Dummy printk for disabled debugging statements to use whilst maintaining
107  * gcc's format and side-effect checking.
108  */
109 static inline __printf(1, 2)
110 int no_printk(const char *fmt, ...)
111 {
112 	return 0;
113 }
114 
115 #ifdef CONFIG_EARLY_PRINTK
116 extern asmlinkage __printf(1, 2)
117 void early_printk(const char *fmt, ...);
118 #else
119 static inline __printf(1, 2) __cold
120 void early_printk(const char *s, ...) { }
121 #endif
122 
123 typedef int(*printk_func_t)(const char *fmt, va_list args);
124 
125 #ifdef CONFIG_PRINTK
126 asmlinkage __printf(5, 0)
127 int vprintk_emit(int facility, int level,
128 		 const char *dict, size_t dictlen,
129 		 const char *fmt, va_list args);
130 
131 asmlinkage __printf(1, 0)
132 int vprintk(const char *fmt, va_list args);
133 
134 asmlinkage __printf(5, 6) __cold
135 int printk_emit(int facility, int level,
136 		const char *dict, size_t dictlen,
137 		const char *fmt, ...);
138 
139 asmlinkage __printf(1, 2) __cold
140 int printk(const char *fmt, ...);
141 
142 /*
143  * Special printk facility for scheduler/timekeeping use only, _DO_NOT_USE_ !
144  */
145 __printf(1, 2) __cold int printk_deferred(const char *fmt, ...);
146 
147 /*
148  * Please don't use printk_ratelimit(), because it shares ratelimiting state
149  * with all other unrelated printk_ratelimit() callsites.  Instead use
150  * printk_ratelimited() or plain old __ratelimit().
151  */
152 extern int __printk_ratelimit(const char *func);
153 #define printk_ratelimit() __printk_ratelimit(__func__)
154 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
155 				   unsigned int interval_msec);
156 
157 extern int printk_delay_msec;
158 extern int dmesg_restrict;
159 extern int kptr_restrict;
160 
161 extern void wake_up_klogd(void);
162 
163 char *log_buf_addr_get(void);
164 u32 log_buf_len_get(void);
165 void log_buf_kexec_setup(void);
166 void __init setup_log_buf(int early);
167 void dump_stack_set_arch_desc(const char *fmt, ...);
168 void dump_stack_print_info(const char *log_lvl);
169 void show_regs_print_info(const char *log_lvl);
170 #else
171 static inline __printf(1, 0)
172 int vprintk(const char *s, va_list args)
173 {
174 	return 0;
175 }
176 static inline __printf(1, 2) __cold
177 int printk(const char *s, ...)
178 {
179 	return 0;
180 }
181 static inline __printf(1, 2) __cold
182 int printk_deferred(const char *s, ...)
183 {
184 	return 0;
185 }
186 static inline int printk_ratelimit(void)
187 {
188 	return 0;
189 }
190 static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies,
191 					  unsigned int interval_msec)
192 {
193 	return false;
194 }
195 
196 static inline void wake_up_klogd(void)
197 {
198 }
199 
200 static inline char *log_buf_addr_get(void)
201 {
202 	return NULL;
203 }
204 
205 static inline u32 log_buf_len_get(void)
206 {
207 	return 0;
208 }
209 
210 static inline void log_buf_kexec_setup(void)
211 {
212 }
213 
214 static inline void setup_log_buf(int early)
215 {
216 }
217 
218 static inline void dump_stack_set_arch_desc(const char *fmt, ...)
219 {
220 }
221 
222 static inline void dump_stack_print_info(const char *log_lvl)
223 {
224 }
225 
226 static inline void show_regs_print_info(const char *log_lvl)
227 {
228 }
229 #endif
230 
231 extern asmlinkage void dump_stack(void) __cold;
232 
233 #ifndef pr_fmt
234 #define pr_fmt(fmt) fmt
235 #endif
236 
237 /*
238  * These can be used to print at the various log levels.
239  * All of these will print unconditionally, although note that pr_debug()
240  * and other debug macros are compiled out unless either DEBUG is defined
241  * or CONFIG_DYNAMIC_DEBUG is set.
242  */
243 #define pr_emerg(fmt, ...) \
244 	printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
245 #define pr_alert(fmt, ...) \
246 	printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
247 #define pr_crit(fmt, ...) \
248 	printk(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
249 #define pr_err(fmt, ...) \
250 	printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
251 #define pr_warning(fmt, ...) \
252 	printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
253 #define pr_warn pr_warning
254 #define pr_notice(fmt, ...) \
255 	printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
256 #define pr_info(fmt, ...) \
257 	printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
258 #define pr_cont(fmt, ...) \
259 	printk(KERN_CONT fmt, ##__VA_ARGS__)
260 
261 /* pr_devel() should produce zero code unless DEBUG is defined */
262 #ifdef DEBUG
263 #define pr_devel(fmt, ...) \
264 	printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
265 #else
266 #define pr_devel(fmt, ...) \
267 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
268 #endif
269 
270 #include <linux/dynamic_debug.h>
271 
272 /* If you are writing a driver, please use dev_dbg instead */
273 #if defined(CONFIG_DYNAMIC_DEBUG)
274 /* dynamic_pr_debug() uses pr_fmt() internally so we don't need it here */
275 #define pr_debug(fmt, ...) \
276 	dynamic_pr_debug(fmt, ##__VA_ARGS__)
277 #elif defined(DEBUG)
278 #define pr_debug(fmt, ...) \
279 	printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
280 #else
281 #define pr_debug(fmt, ...) \
282 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
283 #endif
284 
285 /*
286  * Print a one-time message (analogous to WARN_ONCE() et al):
287  */
288 
289 #ifdef CONFIG_PRINTK
290 #define printk_once(fmt, ...)					\
291 ({								\
292 	static bool __print_once __read_mostly;			\
293 								\
294 	if (!__print_once) {					\
295 		__print_once = true;				\
296 		printk(fmt, ##__VA_ARGS__);			\
297 	}							\
298 })
299 #define printk_deferred_once(fmt, ...)				\
300 ({								\
301 	static bool __print_once __read_mostly;			\
302 								\
303 	if (!__print_once) {					\
304 		__print_once = true;				\
305 		printk_deferred(fmt, ##__VA_ARGS__);		\
306 	}							\
307 })
308 #else
309 #define printk_once(fmt, ...)					\
310 	no_printk(fmt, ##__VA_ARGS__)
311 #define printk_deferred_once(fmt, ...)				\
312 	no_printk(fmt, ##__VA_ARGS__)
313 #endif
314 
315 #define pr_emerg_once(fmt, ...)					\
316 	printk_once(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
317 #define pr_alert_once(fmt, ...)					\
318 	printk_once(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
319 #define pr_crit_once(fmt, ...)					\
320 	printk_once(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
321 #define pr_err_once(fmt, ...)					\
322 	printk_once(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
323 #define pr_warn_once(fmt, ...)					\
324 	printk_once(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
325 #define pr_notice_once(fmt, ...)				\
326 	printk_once(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
327 #define pr_info_once(fmt, ...)					\
328 	printk_once(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
329 #define pr_cont_once(fmt, ...)					\
330 	printk_once(KERN_CONT pr_fmt(fmt), ##__VA_ARGS__)
331 
332 #if defined(DEBUG)
333 #define pr_devel_once(fmt, ...)					\
334 	printk_once(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
335 #else
336 #define pr_devel_once(fmt, ...)					\
337 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
338 #endif
339 
340 /* If you are writing a driver, please use dev_dbg instead */
341 #if defined(DEBUG)
342 #define pr_debug_once(fmt, ...)					\
343 	printk_once(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
344 #else
345 #define pr_debug_once(fmt, ...)					\
346 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
347 #endif
348 
349 /*
350  * ratelimited messages with local ratelimit_state,
351  * no local ratelimit_state used in the !PRINTK case
352  */
353 #ifdef CONFIG_PRINTK
354 #define printk_ratelimited(fmt, ...)					\
355 ({									\
356 	static DEFINE_RATELIMIT_STATE(_rs,				\
357 				      DEFAULT_RATELIMIT_INTERVAL,	\
358 				      DEFAULT_RATELIMIT_BURST);		\
359 									\
360 	if (__ratelimit(&_rs))						\
361 		printk(fmt, ##__VA_ARGS__);				\
362 })
363 #else
364 #define printk_ratelimited(fmt, ...)					\
365 	no_printk(fmt, ##__VA_ARGS__)
366 #endif
367 
368 #define pr_emerg_ratelimited(fmt, ...)					\
369 	printk_ratelimited(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
370 #define pr_alert_ratelimited(fmt, ...)					\
371 	printk_ratelimited(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
372 #define pr_crit_ratelimited(fmt, ...)					\
373 	printk_ratelimited(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
374 #define pr_err_ratelimited(fmt, ...)					\
375 	printk_ratelimited(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
376 #define pr_warn_ratelimited(fmt, ...)					\
377 	printk_ratelimited(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
378 #define pr_notice_ratelimited(fmt, ...)					\
379 	printk_ratelimited(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
380 #define pr_info_ratelimited(fmt, ...)					\
381 	printk_ratelimited(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
382 /* no pr_cont_ratelimited, don't do that... */
383 
384 #if defined(DEBUG)
385 #define pr_devel_ratelimited(fmt, ...)					\
386 	printk_ratelimited(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
387 #else
388 #define pr_devel_ratelimited(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(CONFIG_DYNAMIC_DEBUG)
394 /* descriptor check is first to prevent flooding with "callbacks suppressed" */
395 #define pr_debug_ratelimited(fmt, ...)					\
396 do {									\
397 	static DEFINE_RATELIMIT_STATE(_rs,				\
398 				      DEFAULT_RATELIMIT_INTERVAL,	\
399 				      DEFAULT_RATELIMIT_BURST);		\
400 	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);			\
401 	if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT) &&	\
402 	    __ratelimit(&_rs))						\
403 		__dynamic_pr_debug(&descriptor, fmt, ##__VA_ARGS__);	\
404 } while (0)
405 #elif defined(DEBUG)
406 #define pr_debug_ratelimited(fmt, ...)					\
407 	printk_ratelimited(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
408 #else
409 #define pr_debug_ratelimited(fmt, ...) \
410 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
411 #endif
412 
413 extern const struct file_operations kmsg_fops;
414 
415 enum {
416 	DUMP_PREFIX_NONE,
417 	DUMP_PREFIX_ADDRESS,
418 	DUMP_PREFIX_OFFSET
419 };
420 extern int hex_dump_to_buffer(const void *buf, size_t len, int rowsize,
421 			      int groupsize, char *linebuf, size_t linebuflen,
422 			      bool ascii);
423 #ifdef CONFIG_PRINTK
424 extern void print_hex_dump(const char *level, const char *prefix_str,
425 			   int prefix_type, int rowsize, int groupsize,
426 			   const void *buf, size_t len, bool ascii);
427 #if defined(CONFIG_DYNAMIC_DEBUG)
428 #define print_hex_dump_bytes(prefix_str, prefix_type, buf, len)	\
429 	dynamic_hex_dump(prefix_str, prefix_type, 16, 1, buf, len, true)
430 #else
431 extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
432 				 const void *buf, size_t len);
433 #endif /* defined(CONFIG_DYNAMIC_DEBUG) */
434 #else
435 static inline void print_hex_dump(const char *level, const char *prefix_str,
436 				  int prefix_type, int rowsize, int groupsize,
437 				  const void *buf, size_t len, bool ascii)
438 {
439 }
440 static inline void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
441 					const void *buf, size_t len)
442 {
443 }
444 
445 #endif
446 
447 #if defined(CONFIG_DYNAMIC_DEBUG)
448 #define print_hex_dump_debug(prefix_str, prefix_type, rowsize,	\
449 			     groupsize, buf, len, ascii)	\
450 	dynamic_hex_dump(prefix_str, prefix_type, rowsize,	\
451 			 groupsize, buf, len, ascii)
452 #else
453 #define print_hex_dump_debug(prefix_str, prefix_type, rowsize,		\
454 			     groupsize, buf, len, ascii)		\
455 	print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, rowsize,	\
456 		       groupsize, buf, len, ascii)
457 #endif /* defined(CONFIG_DYNAMIC_DEBUG) */
458 
459 #endif
460