xref: /linux-6.15/include/linux/printk.h (revision db181ce0)
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 DEFAULT_MESSAGE_LOGLEVEL CONFIG_DEFAULT_MESSAGE_LOGLEVEL
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 void early_vprintk(const char *fmt, va_list ap);
119 #else
120 static inline __printf(1, 2) __cold
121 void early_printk(const char *s, ...) { }
122 #endif
123 
124 #ifdef CONFIG_PRINTK
125 asmlinkage __printf(5, 0)
126 int vprintk_emit(int facility, int level,
127 		 const char *dict, size_t dictlen,
128 		 const char *fmt, va_list args);
129 
130 asmlinkage __printf(1, 0)
131 int vprintk(const char *fmt, va_list args);
132 
133 asmlinkage __printf(5, 6) __cold
134 int printk_emit(int facility, int level,
135 		const char *dict, size_t dictlen,
136 		const char *fmt, ...);
137 
138 asmlinkage __printf(1, 2) __cold
139 int printk(const char *fmt, ...);
140 
141 /*
142  * Special printk facility for scheduler/timekeeping use only, _DO_NOT_USE_ !
143  */
144 __printf(1, 2) __cold int printk_deferred(const char *fmt, ...);
145 
146 /*
147  * Please don't use printk_ratelimit(), because it shares ratelimiting state
148  * with all other unrelated printk_ratelimit() callsites.  Instead use
149  * printk_ratelimited() or plain old __ratelimit().
150  */
151 extern int __printk_ratelimit(const char *func);
152 #define printk_ratelimit() __printk_ratelimit(__func__)
153 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
154 				   unsigned int interval_msec);
155 
156 extern int printk_delay_msec;
157 extern int dmesg_restrict;
158 extern int kptr_restrict;
159 
160 extern void wake_up_klogd(void);
161 
162 void log_buf_kexec_setup(void);
163 void __init setup_log_buf(int early);
164 void dump_stack_set_arch_desc(const char *fmt, ...);
165 void dump_stack_print_info(const char *log_lvl);
166 void show_regs_print_info(const char *log_lvl);
167 #else
168 static inline __printf(1, 0)
169 int vprintk(const char *s, va_list args)
170 {
171 	return 0;
172 }
173 static inline __printf(1, 2) __cold
174 int printk(const char *s, ...)
175 {
176 	return 0;
177 }
178 static inline __printf(1, 2) __cold
179 int printk_deferred(const char *s, ...)
180 {
181 	return 0;
182 }
183 static inline int printk_ratelimit(void)
184 {
185 	return 0;
186 }
187 static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies,
188 					  unsigned int interval_msec)
189 {
190 	return false;
191 }
192 
193 static inline void wake_up_klogd(void)
194 {
195 }
196 
197 static inline void log_buf_kexec_setup(void)
198 {
199 }
200 
201 static inline void setup_log_buf(int early)
202 {
203 }
204 
205 static inline void dump_stack_set_arch_desc(const char *fmt, ...)
206 {
207 }
208 
209 static inline void dump_stack_print_info(const char *log_lvl)
210 {
211 }
212 
213 static inline void show_regs_print_info(const char *log_lvl)
214 {
215 }
216 #endif
217 
218 extern asmlinkage void dump_stack(void) __cold;
219 
220 #ifndef pr_fmt
221 #define pr_fmt(fmt) fmt
222 #endif
223 
224 /*
225  * These can be used to print at the various log levels.
226  * All of these will print unconditionally, although note that pr_debug()
227  * and other debug macros are compiled out unless either DEBUG is defined
228  * or CONFIG_DYNAMIC_DEBUG is set.
229  */
230 #define pr_emerg(fmt, ...) \
231 	printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
232 #define pr_alert(fmt, ...) \
233 	printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
234 #define pr_crit(fmt, ...) \
235 	printk(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
236 #define pr_err(fmt, ...) \
237 	printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
238 #define pr_warning(fmt, ...) \
239 	printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
240 #define pr_warn pr_warning
241 #define pr_notice(fmt, ...) \
242 	printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
243 #define pr_info(fmt, ...) \
244 	printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
245 #define pr_cont(fmt, ...) \
246 	printk(KERN_CONT fmt, ##__VA_ARGS__)
247 
248 /* pr_devel() should produce zero code unless DEBUG is defined */
249 #ifdef DEBUG
250 #define pr_devel(fmt, ...) \
251 	printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
252 #else
253 #define pr_devel(fmt, ...) \
254 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
255 #endif
256 
257 #include <linux/dynamic_debug.h>
258 
259 /* If you are writing a driver, please use dev_dbg instead */
260 #if defined(CONFIG_DYNAMIC_DEBUG)
261 /* dynamic_pr_debug() uses pr_fmt() internally so we don't need it here */
262 #define pr_debug(fmt, ...) \
263 	dynamic_pr_debug(fmt, ##__VA_ARGS__)
264 #elif defined(DEBUG)
265 #define pr_debug(fmt, ...) \
266 	printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
267 #else
268 #define pr_debug(fmt, ...) \
269 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
270 #endif
271 
272 /*
273  * Print a one-time message (analogous to WARN_ONCE() et al):
274  */
275 
276 #ifdef CONFIG_PRINTK
277 #define printk_once(fmt, ...)					\
278 ({								\
279 	static bool __print_once __read_mostly;			\
280 								\
281 	if (!__print_once) {					\
282 		__print_once = true;				\
283 		printk(fmt, ##__VA_ARGS__);			\
284 	}							\
285 })
286 #define printk_deferred_once(fmt, ...)				\
287 ({								\
288 	static bool __print_once __read_mostly;			\
289 								\
290 	if (!__print_once) {					\
291 		__print_once = true;				\
292 		printk_deferred(fmt, ##__VA_ARGS__);		\
293 	}							\
294 })
295 #else
296 #define printk_once(fmt, ...)					\
297 	no_printk(fmt, ##__VA_ARGS__)
298 #define printk_deferred_once(fmt, ...)				\
299 	no_printk(fmt, ##__VA_ARGS__)
300 #endif
301 
302 #define pr_emerg_once(fmt, ...)					\
303 	printk_once(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
304 #define pr_alert_once(fmt, ...)					\
305 	printk_once(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
306 #define pr_crit_once(fmt, ...)					\
307 	printk_once(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
308 #define pr_err_once(fmt, ...)					\
309 	printk_once(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
310 #define pr_warn_once(fmt, ...)					\
311 	printk_once(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
312 #define pr_notice_once(fmt, ...)				\
313 	printk_once(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
314 #define pr_info_once(fmt, ...)					\
315 	printk_once(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
316 #define pr_cont_once(fmt, ...)					\
317 	printk_once(KERN_CONT pr_fmt(fmt), ##__VA_ARGS__)
318 
319 #if defined(DEBUG)
320 #define pr_devel_once(fmt, ...)					\
321 	printk_once(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
322 #else
323 #define pr_devel_once(fmt, ...)					\
324 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
325 #endif
326 
327 /* If you are writing a driver, please use dev_dbg instead */
328 #if defined(DEBUG)
329 #define pr_debug_once(fmt, ...)					\
330 	printk_once(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
331 #else
332 #define pr_debug_once(fmt, ...)					\
333 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
334 #endif
335 
336 /*
337  * ratelimited messages with local ratelimit_state,
338  * no local ratelimit_state used in the !PRINTK case
339  */
340 #ifdef CONFIG_PRINTK
341 #define printk_ratelimited(fmt, ...)					\
342 ({									\
343 	static DEFINE_RATELIMIT_STATE(_rs,				\
344 				      DEFAULT_RATELIMIT_INTERVAL,	\
345 				      DEFAULT_RATELIMIT_BURST);		\
346 									\
347 	if (__ratelimit(&_rs))						\
348 		printk(fmt, ##__VA_ARGS__);				\
349 })
350 #else
351 #define printk_ratelimited(fmt, ...)					\
352 	no_printk(fmt, ##__VA_ARGS__)
353 #endif
354 
355 #define pr_emerg_ratelimited(fmt, ...)					\
356 	printk_ratelimited(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
357 #define pr_alert_ratelimited(fmt, ...)					\
358 	printk_ratelimited(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
359 #define pr_crit_ratelimited(fmt, ...)					\
360 	printk_ratelimited(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
361 #define pr_err_ratelimited(fmt, ...)					\
362 	printk_ratelimited(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
363 #define pr_warn_ratelimited(fmt, ...)					\
364 	printk_ratelimited(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
365 #define pr_notice_ratelimited(fmt, ...)					\
366 	printk_ratelimited(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
367 #define pr_info_ratelimited(fmt, ...)					\
368 	printk_ratelimited(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
369 /* no pr_cont_ratelimited, don't do that... */
370 
371 #if defined(DEBUG)
372 #define pr_devel_ratelimited(fmt, ...)					\
373 	printk_ratelimited(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
374 #else
375 #define pr_devel_ratelimited(fmt, ...)					\
376 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
377 #endif
378 
379 /* If you are writing a driver, please use dev_dbg instead */
380 #if defined(CONFIG_DYNAMIC_DEBUG)
381 /* descriptor check is first to prevent flooding with "callbacks suppressed" */
382 #define pr_debug_ratelimited(fmt, ...)					\
383 do {									\
384 	static DEFINE_RATELIMIT_STATE(_rs,				\
385 				      DEFAULT_RATELIMIT_INTERVAL,	\
386 				      DEFAULT_RATELIMIT_BURST);		\
387 	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);			\
388 	if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT) &&	\
389 	    __ratelimit(&_rs))						\
390 		__dynamic_pr_debug(&descriptor, fmt, ##__VA_ARGS__);	\
391 } while (0)
392 #elif defined(DEBUG)
393 #define pr_debug_ratelimited(fmt, ...)					\
394 	printk_ratelimited(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
395 #else
396 #define pr_debug_ratelimited(fmt, ...) \
397 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
398 #endif
399 
400 extern const struct file_operations kmsg_fops;
401 
402 enum {
403 	DUMP_PREFIX_NONE,
404 	DUMP_PREFIX_ADDRESS,
405 	DUMP_PREFIX_OFFSET
406 };
407 extern void hex_dump_to_buffer(const void *buf, size_t len,
408 			       int rowsize, int groupsize,
409 			       char *linebuf, size_t linebuflen, bool ascii);
410 #ifdef CONFIG_PRINTK
411 extern void print_hex_dump(const char *level, const char *prefix_str,
412 			   int prefix_type, int rowsize, int groupsize,
413 			   const void *buf, size_t len, bool ascii);
414 #if defined(CONFIG_DYNAMIC_DEBUG)
415 #define print_hex_dump_bytes(prefix_str, prefix_type, buf, len)	\
416 	dynamic_hex_dump(prefix_str, prefix_type, 16, 1, buf, len, true)
417 #else
418 extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
419 				 const void *buf, size_t len);
420 #endif /* defined(CONFIG_DYNAMIC_DEBUG) */
421 #else
422 static inline void print_hex_dump(const char *level, const char *prefix_str,
423 				  int prefix_type, int rowsize, int groupsize,
424 				  const void *buf, size_t len, bool ascii)
425 {
426 }
427 static inline void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
428 					const void *buf, size_t len)
429 {
430 }
431 
432 #endif
433 
434 #if defined(CONFIG_DYNAMIC_DEBUG)
435 #define print_hex_dump_debug(prefix_str, prefix_type, rowsize,	\
436 			     groupsize, buf, len, ascii)	\
437 	dynamic_hex_dump(prefix_str, prefix_type, rowsize,	\
438 			 groupsize, buf, len, ascii)
439 #else
440 #define print_hex_dump_debug(prefix_str, prefix_type, rowsize,		\
441 			     groupsize, buf, len, ascii)		\
442 	print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, rowsize,	\
443 		       groupsize, buf, len, ascii)
444 #endif /* defined(CONFIG_DYNAMIC_DEBUG) */
445 
446 #endif
447