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