include/linux/printk.h

   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         do {                                            \
 136                 if (0)                                  \
 137                         printk(fmt, ##__VA_ARGS__);     \
 138         } while (0);                                    \
 139         0;                                              \
 140 })
 141
 142 #ifdef CONFIG_EARLY_PRINTK
 143 extern asmlinkage __printf(1, 2)
 144 void early_printk(const char *fmt, ...);
 145 #else
 146 static inline __printf(1, 2) __cold
 147 void early_printk(const char *s, ...) { }
 148 #endif
 149
 150 #ifdef CONFIG_PRINTK_NMI
 151 extern void printk_nmi_enter(void);
 152 extern void printk_nmi_exit(void);
 153 extern void printk_nmi_direct_enter(void);
 154 extern void printk_nmi_direct_exit(void);
 155 #else
 156 static inline void printk_nmi_enter(void) { }
 157 static inline void printk_nmi_exit(void) { }
 158 static inline void printk_nmi_direct_enter(void) { }
 159 static inline void printk_nmi_direct_exit(void) { }
 160 #endif /* PRINTK_NMI */
 161
 162 #ifdef CONFIG_PRINTK
 163 asmlinkage __printf(5, 0)
 164 int vprintk_emit(int facility, int level,
 165                  const char *dict, size_t dictlen,
 166                  const char *fmt, va_list args);
 167
 168 asmlinkage __printf(1, 0)
 169 int vprintk(const char *fmt, va_list args);
 170
 171 asmlinkage __printf(5, 6) __cold
 172 int printk_emit(int facility, int level,
 173                 const char *dict, size_t dictlen,
 174                 const char *fmt, ...);
 175
 176 asmlinkage __printf(1, 2) __cold
 177 int printk(const char *fmt, ...);
 178
 179 /*
 180  * Special printk facility for scheduler/timekeeping use only, _DO_NOT_USE_ !
 181  */
 182 __printf(1, 2) __cold int printk_deferred(const char *fmt, ...);
 183
 184 /*
 185  * Please don't use printk_ratelimit(), because it shares ratelimiting state
 186  * with all other unrelated printk_ratelimit() callsites.  Instead use
 187  * printk_ratelimited() or plain old __ratelimit().
 188  */
 189 extern int __printk_ratelimit(const char *func);
 190 #define printk_ratelimit() __printk_ratelimit(__func__)
 191 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
 192                                    unsigned int interval_msec);
 193
 194 extern int printk_delay_msec;
 195 extern int dmesg_restrict;
 196 extern int kptr_restrict;
 197
 198 extern int
 199 devkmsg_sysctl_set_loglvl(struct ctl_table *table, int write, void __user *buf,
 200                           size_t *lenp, loff_t *ppos);
 201
 202 extern void wake_up_klogd(void);
 203
 204 char *log_buf_addr_get(void);
 205 u32 log_buf_len_get(void);
 206 void log_buf_vmcoreinfo_setup(void);
 207 void __init setup_log_buf(int early);
 208 __printf(1, 2) void dump_stack_set_arch_desc(const char *fmt, ...);
 209 void dump_stack_print_info(const char *log_lvl);
 210 void show_regs_print_info(const char *log_lvl);
 211 extern void printk_safe_init(void);
 212 extern void printk_safe_flush(void);
 213 extern void printk_safe_flush_on_panic(void);
 214 #else
 215 static inline __printf(1, 0)
 216 int vprintk(const char *s, va_list args)
 217 {
 218         return 0;
 219 }
 220 static inline __printf(1, 2) __cold
 221 int printk(const char *s, ...)
 222 {
 223         return 0;
 224 }
 225 static inline __printf(1, 2) __cold
 226 int printk_deferred(const char *s, ...)
 227 {
 228         return 0;
 229 }
 230 static inline int printk_ratelimit(void)
 231 {
 232         return 0;
 233 }
 234 static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies,
 235                                           unsigned int interval_msec)
 236 {
 237         return false;
 238 }
 239
 240 static inline void wake_up_klogd(void)
 241 {
 242 }
 243
 244 static inline char *log_buf_addr_get(void)
 245 {
 246         return NULL;
 247 }
 248
 249 static inline u32 log_buf_len_get(void)
 250 {
 251         return 0;
 252 }
 253
 254 static inline void log_buf_vmcoreinfo_setup(void)
 255 {
 256 }
 257
 258 static inline void setup_log_buf(int early)
 259 {
 260 }
 261
 262 static inline __printf(1, 2) void dump_stack_set_arch_desc(const char *fmt, ...)
 263 {
 264 }
 265
 266 static inline void dump_stack_print_info(const char *log_lvl)
 267 {
 268 }
 269
 270 static inline void show_regs_print_info(const char *log_lvl)
 271 {
 272 }
 273
 274 static inline void printk_safe_init(void)
 275 {
 276 }
 277
 278 static inline void printk_safe_flush(void)
 279 {
 280 }
 281
 282 static inline void printk_safe_flush_on_panic(void)
 283 {
 284 }
 285 #endif
 286
 287 extern asmlinkage void dump_stack(void) __cold;
 288
 289 #ifndef pr_fmt
 290 #define pr_fmt(fmt) fmt
 291 #endif
 292
 293 /*
 294  * These can be used to print at the various log levels.
 295  * All of these will print unconditionally, although note that pr_debug()
 296  * and other debug macros are compiled out unless either DEBUG is defined
 297  * or CONFIG_DYNAMIC_DEBUG is set.
 298  */
 299 #define pr_emerg(fmt, ...) \
 300         printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
 301 #define pr_alert(fmt, ...) \
 302         printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
 303 #define pr_crit(fmt, ...) \
 304         printk(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
 305 #define pr_err(fmt, ...) \
 306         printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
 307 #define pr_warning(fmt, ...) \
 308         printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
 309 #define pr_warn pr_warning
 310 #define pr_notice(fmt, ...) \
 311         printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
 312 #define pr_info(fmt, ...) \
 313         printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
 314 /*
 315  * Like KERN_CONT, pr_cont() should only be used when continuing
 316  * a line with no newline ('\n') enclosed. Otherwise it defaults
 317  * back to KERN_DEFAULT.
 318  */
 319 #define pr_cont(fmt, ...) \
 320         printk(KERN_CONT fmt, ##__VA_ARGS__)
 321
 322 /* pr_devel() should produce zero code unless DEBUG is defined */
 323 #ifdef DEBUG
 324 #define pr_devel(fmt, ...) \
 325         printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 326 #else
 327 #define pr_devel(fmt, ...) \
 328         no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 329 #endif
 330
 331
 332 /* If you are writing a driver, please use dev_dbg instead */
 333 #if defined(CONFIG_DYNAMIC_DEBUG)
 334 #include <linux/dynamic_debug.h>
 335
 336 /* dynamic_pr_debug() uses pr_fmt() internally so we don't need it here */
 337 #define pr_debug(fmt, ...) \
 338         dynamic_pr_debug(fmt, ##__VA_ARGS__)
 339 #elif defined(DEBUG)
 340 #define pr_debug(fmt, ...) \
 341         printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 342 #else
 343 #define pr_debug(fmt, ...) \
 344         no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 345 #endif
 346
 347 /*
 348  * Print a one-time message (analogous to WARN_ONCE() et al):
 349  */
 350
 351 #ifdef CONFIG_PRINTK
 352 #define printk_once(fmt, ...)                                   \
 353 ({                                                              \
 354         static bool __print_once __read_mostly;                 \
 355         bool __ret_print_once = !__print_once;                  \
 356                                                                 \
 357         if (!__print_once) {                                    \
 358                 __print_once = true;                            \
 359                 printk(fmt, ##__VA_ARGS__);                     \
 360         }                                                       \
 361         unlikely(__ret_print_once);                             \
 362 })
 363 #define printk_deferred_once(fmt, ...)                          \
 364 ({                                                              \
 365         static bool __print_once __read_mostly;                 \
 366         bool __ret_print_once = !__print_once;                  \
 367                                                                 \
 368         if (!__print_once) {                                    \
 369                 __print_once = true;                            \
 370                 printk_deferred(fmt, ##__VA_ARGS__);            \
 371         }                                                       \
 372         unlikely(__ret_print_once);                             \
 373 })
 374 #else
 375 #define printk_once(fmt, ...)                                   \
 376         no_printk(fmt, ##__VA_ARGS__)
 377 #define printk_deferred_once(fmt, ...)                          \
 378         no_printk(fmt, ##__VA_ARGS__)
 379 #endif
 380
 381 #define pr_emerg_once(fmt, ...)                                 \
 382         printk_once(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
 383 #define pr_alert_once(fmt, ...)                                 \
 384         printk_once(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
 385 #define pr_crit_once(fmt, ...)                                  \
 386         printk_once(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
 387 #define pr_err_once(fmt, ...)                                   \
 388         printk_once(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
 389 #define pr_warn_once(fmt, ...)                                  \
 390         printk_once(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
 391 #define pr_notice_once(fmt, ...)                                \
 392         printk_once(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
 393 #define pr_info_once(fmt, ...)                                  \
 394         printk_once(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
 395 #define pr_cont_once(fmt, ...)                                  \
 396         printk_once(KERN_CONT pr_fmt(fmt), ##__VA_ARGS__)
 397
 398 #if defined(DEBUG)
 399 #define pr_devel_once(fmt, ...)                                 \
 400         printk_once(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 401 #else
 402 #define pr_devel_once(fmt, ...)                                 \
 403         no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 404 #endif
 405
 406 /* If you are writing a driver, please use dev_dbg instead */
 407 #if defined(DEBUG)
 408 #define pr_debug_once(fmt, ...)                                 \
 409         printk_once(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 410 #else
 411 #define pr_debug_once(fmt, ...)                                 \
 412         no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 413 #endif
 414
 415 /*
 416  * ratelimited messages with local ratelimit_state,
 417  * no local ratelimit_state used in the !PRINTK case
 418  */
 419 #ifdef CONFIG_PRINTK
 420 #define printk_ratelimited(fmt, ...)                                    \
 421 ({                                                                      \
 422         static DEFINE_RATELIMIT_STATE(_rs,                              \
 423                                       DEFAULT_RATELIMIT_INTERVAL,       \
 424                                       DEFAULT_RATELIMIT_BURST);         \
 425                                                                         \
 426         if (__ratelimit(&_rs))                                          \
 427                 printk(fmt, ##__VA_ARGS__);                             \
 428 })
 429 #else
 430 #define printk_ratelimited(fmt, ...)                                    \
 431         no_printk(fmt, ##__VA_ARGS__)
 432 #endif
 433
 434 #define pr_emerg_ratelimited(fmt, ...)                                  \
 435         printk_ratelimited(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
 436 #define pr_alert_ratelimited(fmt, ...)                                  \
 437         printk_ratelimited(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
 438 #define pr_crit_ratelimited(fmt, ...)                                   \
 439         printk_ratelimited(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
 440 #define pr_err_ratelimited(fmt, ...)                                    \
 441         printk_ratelimited(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
 442 #define pr_warn_ratelimited(fmt, ...)                                   \
 443         printk_ratelimited(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
 444 #define pr_notice_ratelimited(fmt, ...)                                 \
 445         printk_ratelimited(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
 446 #define pr_info_ratelimited(fmt, ...)                                   \
 447         printk_ratelimited(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
 448 /* no pr_cont_ratelimited, don't do that... */
 449
 450 #if defined(DEBUG)
 451 #define pr_devel_ratelimited(fmt, ...)                                  \
 452         printk_ratelimited(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 453 #else
 454 #define pr_devel_ratelimited(fmt, ...)                                  \
 455         no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 456 #endif
 457
 458 /* If you are writing a driver, please use dev_dbg instead */
 459 #if defined(CONFIG_DYNAMIC_DEBUG)
 460 /* descriptor check is first to prevent flooding with "callbacks suppressed" */
 461 #define pr_debug_ratelimited(fmt, ...)                                  \
 462 do {                                                                    \
 463         static DEFINE_RATELIMIT_STATE(_rs,                              \
 464                                       DEFAULT_RATELIMIT_INTERVAL,       \
 465                                       DEFAULT_RATELIMIT_BURST);         \
 466         DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, pr_fmt(fmt));         \
 467         if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT) &&        \
 468             __ratelimit(&_rs))                                          \
 469                 __dynamic_pr_debug(&descriptor, pr_fmt(fmt), ##__VA_ARGS__);    \
 470 } while (0)
 471 #elif defined(DEBUG)
 472 #define pr_debug_ratelimited(fmt, ...)                                  \
 473         printk_ratelimited(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 474 #else
 475 #define pr_debug_ratelimited(fmt, ...) \
 476         no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 477 #endif
 478
 479 extern const struct file_operations kmsg_fops;
 480
 481 enum {
 482         DUMP_PREFIX_NONE,
 483         DUMP_PREFIX_ADDRESS,
 484         DUMP_PREFIX_OFFSET
 485 };
 486 extern int hex_dump_to_buffer(const void *buf, size_t len, int rowsize,
 487                               int groupsize, char *linebuf, size_t linebuflen,
 488                               bool ascii);
 489 #ifdef CONFIG_PRINTK
 490 extern void print_hex_dump(const char *level, const char *prefix_str,
 491                            int prefix_type, int rowsize, int groupsize,
 492                            const void *buf, size_t len, bool ascii);
 493 #if defined(CONFIG_DYNAMIC_DEBUG)
 494 #define print_hex_dump_bytes(prefix_str, prefix_type, buf, len) \
 495         dynamic_hex_dump(prefix_str, prefix_type, 16, 1, buf, len, true)
 496 #else
 497 extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
 498                                  const void *buf, size_t len);
 499 #endif /* defined(CONFIG_DYNAMIC_DEBUG) */
 500 #else
 501 static inline void print_hex_dump(const char *level, const char *prefix_str,
 502                                   int prefix_type, int rowsize, int groupsize,
 503                                   const void *buf, size_t len, bool ascii)
 504 {
 505 }
 506 static inline void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
 507                                         const void *buf, size_t len)
 508 {
 509 }
 510
 511 #endif
 512
 513 #if defined(CONFIG_DYNAMIC_DEBUG)
 514 #define print_hex_dump_debug(prefix_str, prefix_type, rowsize,  \
 515                              groupsize, buf, len, ascii)        \
 516         dynamic_hex_dump(prefix_str, prefix_type, rowsize,      \
 517                          groupsize, buf, len, ascii)
 518 #elif defined(DEBUG)
 519 #define print_hex_dump_debug(prefix_str, prefix_type, rowsize,          \
 520                              groupsize, buf, len, ascii)                \
 521         print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, rowsize,    \
 522                        groupsize, buf, len, ascii)
 523 #else
 524 static inline void print_hex_dump_debug(const char *prefix_str, int prefix_type,
 525                                         int rowsize, int groupsize,
 526                                         const void *buf, size_t len, bool ascii)
 527 {
 528 }
 529 #endif
 530
 531 #endif