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         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 extern void printk_nmi_direct_enter(void);
 152 extern void printk_nmi_direct_exit(void);
 153 #else
 154 static inline void printk_nmi_enter(void) { }
 155 static inline void printk_nmi_exit(void) { }
 156 static inline void printk_nmi_direct_enter(void) { }
 157 static inline void printk_nmi_direct_exit(void) { }
 158 #endif /* PRINTK_NMI */
 159
 160 #ifdef CONFIG_PRINTK
 161 asmlinkage __printf(5, 0)
 162 int vprintk_emit(int facility, int level,
 163                  const char *dict, size_t dictlen,
 164                  const char *fmt, va_list args);
 165
 166 asmlinkage __printf(1, 0)
 167 int vprintk(const char *fmt, va_list args);
 168
 169 asmlinkage __printf(5, 6) __cold
 170 int printk_emit(int facility, int level,
 171                 const char *dict, size_t dictlen,
 172                 const char *fmt, ...);
 173
 174 asmlinkage __printf(1, 2) __cold
 175 int printk(const char *fmt, ...);
 176
 177 /*
 178  * Special printk facility for scheduler/timekeeping use only, _DO_NOT_USE_ !
 179  */
 180 __printf(1, 2) __cold int printk_deferred(const char *fmt, ...);
 181
 182 /*
 183  * Please don't use printk_ratelimit(), because it shares ratelimiting state
 184  * with all other unrelated printk_ratelimit() callsites.  Instead use
 185  * printk_ratelimited() or plain old __ratelimit().
 186  */
 187 extern int __printk_ratelimit(const char *func);
 188 #define printk_ratelimit() __printk_ratelimit(__func__)
 189 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
 190                                    unsigned int interval_msec);
 191
 192 extern int printk_delay_msec;
 193 extern int dmesg_restrict;
 194
 195 extern int
 196 devkmsg_sysctl_set_loglvl(struct ctl_table *table, int write, void __user *buf,
 197                           size_t *lenp, loff_t *ppos);
 198
 199 extern void wake_up_klogd(void);
 200
 201 char *log_buf_addr_get(void);
 202 u32 log_buf_len_get(void);
 203 void log_buf_vmcoreinfo_setup(void);
 204 void __init setup_log_buf(int early);
 205 __printf(1, 2) void dump_stack_set_arch_desc(const char *fmt, ...);
 206 void dump_stack_print_info(const char *log_lvl);
 207 void show_regs_print_info(const char *log_lvl);
 208 extern void printk_safe_init(void);
 209 extern void printk_safe_flush(void);
 210 extern void printk_safe_flush_on_panic(void);
 211 #else
 212 static inline __printf(1, 0)
 213 int vprintk(const char *s, va_list args)
 214 {
 215         return 0;
 216 }
 217 static inline __printf(1, 2) __cold
 218 int printk(const char *s, ...)
 219 {
 220         return 0;
 221 }
 222 static inline __printf(1, 2) __cold
 223 int printk_deferred(const char *s, ...)
 224 {
 225         return 0;
 226 }
 227 static inline int printk_ratelimit(void)
 228 {
 229         return 0;
 230 }
 231 static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies,
 232                                           unsigned int interval_msec)
 233 {
 234         return false;
 235 }
 236
 237 static inline void wake_up_klogd(void)
 238 {
 239 }
 240
 241 static inline char *log_buf_addr_get(void)
 242 {
 243         return NULL;
 244 }
 245
 246 static inline u32 log_buf_len_get(void)
 247 {
 248         return 0;
 249 }
 250
 251 static inline void log_buf_vmcoreinfo_setup(void)
 252 {
 253 }
 254
 255 static inline void setup_log_buf(int early)
 256 {
 257 }
 258
 259 static inline __printf(1, 2) void dump_stack_set_arch_desc(const char *fmt, ...)
 260 {
 261 }
 262
 263 static inline void dump_stack_print_info(const char *log_lvl)
 264 {
 265 }
 266
 267 static inline void show_regs_print_info(const char *log_lvl)
 268 {
 269 }
 270
 271 static inline void printk_safe_init(void)
 272 {
 273 }
 274
 275 static inline void printk_safe_flush(void)
 276 {
 277 }
 278
 279 static inline void printk_safe_flush_on_panic(void)
 280 {
 281 }
 282 #endif
 283
 284 extern int kptr_restrict;
 285
 286 extern asmlinkage void dump_stack(void) __cold;
 287
 288 #ifndef pr_fmt
 289 #define pr_fmt(fmt) fmt
 290 #endif
 291
 292 #if defined(__KMSG_CHECKER) && defined(KMSG_COMPONENT)
 293
 294 /* generate magic string for scripts/kmsg-doc to parse */
 295 #define pr_printk_hash(level, format, ...) \
 296         __KMSG_PRINT(level _FMT_ format _ARGS_ __VA_ARGS__ _END_)
 297
 298 #elif defined(CONFIG_KMSG_IDS) && defined(KMSG_COMPONENT)
 299
 300 /* format element '%pj' prints the six digit jhash of a string */
 301 #define _pr_printk_hash(pfx, fmt, ...) \
 302         printk(pfx fmt, pfx fmt + __builtin_strlen(pfx), ##__VA_ARGS__)
 303 #define pr_printk_hash(level, format, ...) \
 304         _pr_printk_hash(level KMSG_COMPONENT ".%pj: ", format, ##__VA_ARGS__)
 305
 306 #else /* !defined(CONFIG_KMSG_IDS) */
 307
 308 #define pr_printk_hash(level, format, ...) \
 309         printk(level pr_fmt(format), ##__VA_ARGS__)
 310
 311 #endif
 312
 313 /*
 314  * These can be used to print at the various log levels.
 315  * All of these will print unconditionally, although note that pr_debug()
 316  * and other debug macros are compiled out unless either DEBUG is defined
 317  * or CONFIG_DYNAMIC_DEBUG is set.
 318  */
 319 #define pr_emerg(fmt, ...) \
 320         pr_printk_hash(KERN_EMERG, fmt, ##__VA_ARGS__)
 321 #define pr_alert(fmt, ...) \
 322         pr_printk_hash(KERN_ALERT, fmt, ##__VA_ARGS__)
 323 #define pr_crit(fmt, ...) \
 324         pr_printk_hash(KERN_CRIT, fmt, ##__VA_ARGS__)
 325 #define pr_err(fmt, ...) \
 326         pr_printk_hash(KERN_ERR, fmt, ##__VA_ARGS__)
 327 #define pr_warning(fmt, ...) \
 328         pr_printk_hash(KERN_WARNING, fmt, ##__VA_ARGS__)
 329 #define pr_warn pr_warning
 330 #define pr_notice(fmt, ...) \
 331         pr_printk_hash(KERN_NOTICE, fmt, ##__VA_ARGS__)
 332 #define pr_info(fmt, ...) \
 333         pr_printk_hash(KERN_INFO, fmt, ##__VA_ARGS__)
 334 /*
 335  * Like KERN_CONT, pr_cont() should only be used when continuing
 336  * a line with no newline ('\n') enclosed. Otherwise it defaults
 337  * back to KERN_DEFAULT.
 338  */
 339 #define pr_cont(fmt, ...) \
 340         printk(KERN_CONT fmt, ##__VA_ARGS__)
 341
 342 /* pr_devel() should produce zero code unless DEBUG is defined */
 343 #ifdef DEBUG
 344 #define pr_devel(fmt, ...) \
 345         printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 346 #else
 347 #define pr_devel(fmt, ...) \
 348         no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 349 #endif
 350
 351
 352 /* If you are writing a driver, please use dev_dbg instead */
 353 #if defined(CONFIG_DYNAMIC_DEBUG)
 354 #include <linux/dynamic_debug.h>
 355
 356 /* dynamic_pr_debug() uses pr_fmt() internally so we don't need it here */
 357 #define pr_debug(fmt, ...) \
 358         dynamic_pr_debug(fmt, ##__VA_ARGS__)
 359 #elif defined(DEBUG)
 360 #define pr_debug(fmt, ...) \
 361         printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 362 #else
 363 #define pr_debug(fmt, ...) \
 364         no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 365 #endif
 366
 367 /*
 368  * Print a one-time message (analogous to WARN_ONCE() et al):
 369  */
 370
 371 #ifdef CONFIG_PRINTK
 372 #define printk_once(fmt, ...)                                   \
 373 ({                                                              \
 374         static bool __print_once __read_mostly;                 \
 375         bool __ret_print_once = !__print_once;                  \
 376                                                                 \
 377         if (!__print_once) {                                    \
 378                 __print_once = true;                            \
 379                 printk(fmt, ##__VA_ARGS__);                     \
 380         }                                                       \
 381         unlikely(__ret_print_once);                             \
 382 })
 383 #define printk_deferred_once(fmt, ...)                          \
 384 ({                                                              \
 385         static bool __print_once __read_mostly;                 \
 386         bool __ret_print_once = !__print_once;                  \
 387                                                                 \
 388         if (!__print_once) {                                    \
 389                 __print_once = true;                            \
 390                 printk_deferred(fmt, ##__VA_ARGS__);            \
 391         }                                                       \
 392         unlikely(__ret_print_once);                             \
 393 })
 394 #else
 395 #define printk_once(fmt, ...)                                   \
 396         no_printk(fmt, ##__VA_ARGS__)
 397 #define printk_deferred_once(fmt, ...)                          \
 398         no_printk(fmt, ##__VA_ARGS__)
 399 #endif
 400
 401 #define pr_emerg_once(fmt, ...)                                 \
 402         printk_once(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
 403 #define pr_alert_once(fmt, ...)                                 \
 404         printk_once(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
 405 #define pr_crit_once(fmt, ...)                                  \
 406         printk_once(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
 407 #define pr_err_once(fmt, ...)                                   \
 408         printk_once(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
 409 #define pr_warn_once(fmt, ...)                                  \
 410         printk_once(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
 411 #define pr_notice_once(fmt, ...)                                \
 412         printk_once(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
 413 #define pr_info_once(fmt, ...)                                  \
 414         printk_once(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
 415 #define pr_cont_once(fmt, ...)                                  \
 416         printk_once(KERN_CONT pr_fmt(fmt), ##__VA_ARGS__)
 417
 418 #if defined(DEBUG)
 419 #define pr_devel_once(fmt, ...)                                 \
 420         printk_once(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 421 #else
 422 #define pr_devel_once(fmt, ...)                                 \
 423         no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 424 #endif
 425
 426 /* If you are writing a driver, please use dev_dbg instead */
 427 #if defined(DEBUG)
 428 #define pr_debug_once(fmt, ...)                                 \
 429         printk_once(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 430 #else
 431 #define pr_debug_once(fmt, ...)                                 \
 432         no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 433 #endif
 434
 435 /*
 436  * ratelimited messages with local ratelimit_state,
 437  * no local ratelimit_state used in the !PRINTK case
 438  */
 439 #ifdef CONFIG_PRINTK
 440 #define printk_ratelimited(fmt, ...)                                    \
 441 ({                                                                      \
 442         static DEFINE_RATELIMIT_STATE(_rs,                              \
 443                                       DEFAULT_RATELIMIT_INTERVAL,       \
 444                                       DEFAULT_RATELIMIT_BURST);         \
 445                                                                         \
 446         if (__ratelimit(&_rs))                                          \
 447                 printk(fmt, ##__VA_ARGS__);                             \
 448 })
 449 #else
 450 #define printk_ratelimited(fmt, ...)                                    \
 451         no_printk(fmt, ##__VA_ARGS__)
 452 #endif
 453
 454 #define pr_emerg_ratelimited(fmt, ...)                                  \
 455         printk_ratelimited(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
 456 #define pr_alert_ratelimited(fmt, ...)                                  \
 457         printk_ratelimited(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
 458 #define pr_crit_ratelimited(fmt, ...)                                   \
 459         printk_ratelimited(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
 460 #define pr_err_ratelimited(fmt, ...)                                    \
 461         printk_ratelimited(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
 462 #define pr_warn_ratelimited(fmt, ...)                                   \
 463         printk_ratelimited(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
 464 #define pr_notice_ratelimited(fmt, ...)                                 \
 465         printk_ratelimited(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
 466 #define pr_info_ratelimited(fmt, ...)                                   \
 467         printk_ratelimited(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
 468 /* no pr_cont_ratelimited, don't do that... */
 469
 470 #if defined(DEBUG)
 471 #define pr_devel_ratelimited(fmt, ...)                                  \
 472         printk_ratelimited(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 473 #else
 474 #define pr_devel_ratelimited(fmt, ...)                                  \
 475         no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 476 #endif
 477
 478 /* If you are writing a driver, please use dev_dbg instead */
 479 #if defined(CONFIG_DYNAMIC_DEBUG)
 480 /* descriptor check is first to prevent flooding with "callbacks suppressed" */
 481 #define pr_debug_ratelimited(fmt, ...)                                  \
 482 do {                                                                    \
 483         static DEFINE_RATELIMIT_STATE(_rs,                              \
 484                                       DEFAULT_RATELIMIT_INTERVAL,       \
 485                                       DEFAULT_RATELIMIT_BURST);         \
 486         DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, pr_fmt(fmt));         \
 487         if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT) &&        \
 488             __ratelimit(&_rs))                                          \
 489                 __dynamic_pr_debug(&descriptor, pr_fmt(fmt), ##__VA_ARGS__);    \
 490 } while (0)
 491 #elif defined(DEBUG)
 492 #define pr_debug_ratelimited(fmt, ...)                                  \
 493         printk_ratelimited(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 494 #else
 495 #define pr_debug_ratelimited(fmt, ...) \
 496         no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 497 #endif
 498
 499 extern const struct file_operations kmsg_fops;
 500
 501 enum {
 502         DUMP_PREFIX_NONE,
 503         DUMP_PREFIX_ADDRESS,
 504         DUMP_PREFIX_OFFSET
 505 };
 506 extern int hex_dump_to_buffer(const void *buf, size_t len, int rowsize,
 507                               int groupsize, char *linebuf, size_t linebuflen,
 508                               bool ascii);
 509 #ifdef CONFIG_PRINTK
 510 extern void print_hex_dump(const char *level, const char *prefix_str,
 511                            int prefix_type, int rowsize, int groupsize,
 512                            const void *buf, size_t len, bool ascii);
 513 #if defined(CONFIG_DYNAMIC_DEBUG)
 514 #define print_hex_dump_bytes(prefix_str, prefix_type, buf, len) \
 515         dynamic_hex_dump(prefix_str, prefix_type, 16, 1, buf, len, true)
 516 #else
 517 extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
 518                                  const void *buf, size_t len);
 519 #endif /* defined(CONFIG_DYNAMIC_DEBUG) */
 520 #else
 521 static inline void print_hex_dump(const char *level, const char *prefix_str,
 522                                   int prefix_type, int rowsize, int groupsize,
 523                                   const void *buf, size_t len, bool ascii)
 524 {
 525 }
 526 static inline void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
 527                                         const void *buf, size_t len)
 528 {
 529 }
 530
 531 #endif
 532
 533 #if defined(CONFIG_DYNAMIC_DEBUG)
 534 #define print_hex_dump_debug(prefix_str, prefix_type, rowsize,  \
 535                              groupsize, buf, len, ascii)        \
 536         dynamic_hex_dump(prefix_str, prefix_type, rowsize,      \
 537                          groupsize, buf, len, ascii)
 538 #elif defined(DEBUG)
 539 #define print_hex_dump_debug(prefix_str, prefix_type, rowsize,          \
 540                              groupsize, buf, len, ascii)                \
 541         print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, rowsize,    \
 542                        groupsize, buf, len, ascii)
 543 #else
 544 static inline void print_hex_dump_debug(const char *prefix_str, int prefix_type,
 545                                         int rowsize, int groupsize,
 546                                         const void *buf, size_t len, bool ascii)
 547 {
 548 }
 549 #endif
 550
 551 #endif