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 'c':       /* KERN_CONT */
  22                         return buffer[1];
  23                 }
  24         }
  25         return 0;
  26 }
  27
  28 static inline const char *printk_skip_level(const char *buffer)
  29 {
  30         if (printk_get_level(buffer))
  31                 return buffer + 2;
  32
  33         return buffer;
  34 }
  35
  36 static inline const char *printk_skip_headers(const char *buffer)
  37 {
  38         while (printk_get_level(buffer))
  39                 buffer = printk_skip_level(buffer);
  40
  41         return buffer;
  42 }
  43
  44 #define CONSOLE_EXT_LOG_MAX     8192
  45
  46 /* printk's without a loglevel use this.. */
  47 #define MESSAGE_LOGLEVEL_DEFAULT CONFIG_MESSAGE_LOGLEVEL_DEFAULT
  48
  49 /* We show everything that is MORE important than this.. */
  50 #define CONSOLE_LOGLEVEL_SILENT  0 /* Mum's the word */
  51 #define CONSOLE_LOGLEVEL_MIN     1 /* Minimum loglevel we let people use */
  52 #define CONSOLE_LOGLEVEL_DEBUG  10 /* issue debug messages */
  53 #define CONSOLE_LOGLEVEL_MOTORMOUTH 15  /* You can't shut this one up */
  54
  55 /*
  56  * Default used to be hard-coded at 7, quiet used to be hardcoded at 4,
  57  * we're now allowing both to be set from kernel config.
  58  */
  59 #define CONSOLE_LOGLEVEL_DEFAULT CONFIG_CONSOLE_LOGLEVEL_DEFAULT
  60 #define CONSOLE_LOGLEVEL_QUIET   CONFIG_CONSOLE_LOGLEVEL_QUIET
  61
  62 extern int console_printk[];
  63
  64 #define console_loglevel (console_printk[0])
  65 #define default_message_loglevel (console_printk[1])
  66 #define minimum_console_loglevel (console_printk[2])
  67 #define default_console_loglevel (console_printk[3])
  68
  69 static inline void console_silent(void)
  70 {
  71         console_loglevel = CONSOLE_LOGLEVEL_SILENT;
  72 }
  73
  74 static inline void console_verbose(void)
  75 {
  76         if (console_loglevel)
  77                 console_loglevel = CONSOLE_LOGLEVEL_MOTORMOUTH;
  78 }
  79
  80 /* strlen("ratelimit") + 1 */
  81 #define DEVKMSG_STR_MAX_SIZE 10
  82 extern char devkmsg_log_str[];
  83 struct ctl_table;
  84
  85 extern int suppress_printk;
  86
  87 struct va_format {
  88         const char *fmt;
  89         va_list *va;
  90 };
  91
  92 /*
  93  * FW_BUG
  94  * Add this to a message where you are sure the firmware is buggy or behaves
  95  * really stupid or out of spec. Be aware that the responsible BIOS developer
  96  * should be able to fix this issue or at least get a concrete idea of the
  97  * problem by reading your message without the need of looking at the kernel
  98  * code.
  99  *
 100  * Use it for definite and high priority BIOS bugs.
 101  *
 102  * FW_WARN
 103  * Use it for not that clear (e.g. could the kernel messed up things already?)
 104  * and medium priority BIOS bugs.
 105  *
 106  * FW_INFO
 107  * Use this one if you want to tell the user or vendor about something
 108  * suspicious, but generally harmless related to the firmware.
 109  *
 110  * Use it for information or very low priority BIOS bugs.
 111  */
 112 #define FW_BUG          "[Firmware Bug]: "
 113 #define FW_WARN         "[Firmware Warn]: "
 114 #define FW_INFO         "[Firmware Info]: "
 115
 116 /*
 117  * HW_ERR
 118  * Add this to a message for hardware errors, so that user can report
 119  * it to hardware vendor instead of LKML or software vendor.
 120  */
 121 #define HW_ERR          "[Hardware Error]: "
 122
 123 /*
 124  * DEPRECATED
 125  * Add this to a message whenever you want to warn user space about the use
 126  * of a deprecated aspect of an API so they can stop using it
 127  */
 128 #define DEPRECATED      "[Deprecated]: "
 129
 130 /*
 131  * Dummy printk for disabled debugging statements to use whilst maintaining
 132  * gcc's format checking.
 133  */
 134 #define no_printk(fmt, ...)                             \
 135 ({                                                      \
 136         if (0)                                          \
 137                 printk(fmt, ##__VA_ARGS__);             \
 138         0;                                              \
 139 })
 140
 141 #ifdef CONFIG_EARLY_PRINTK
 142 extern asmlinkage __printf(1, 2)
 143 void early_printk(const char *fmt, ...);
 144 #else
 145 static inline __printf(1, 2) __cold
 146 void early_printk(const char *s, ...) { }
 147 #endif
 148
 149 #ifdef CONFIG_PRINTK_NMI
 150 extern void printk_nmi_enter(void);
 151 extern void printk_nmi_exit(void);
 152 extern void printk_nmi_direct_enter(void);
 153 extern void printk_nmi_direct_exit(void);
 154 #else
 155 static inline void printk_nmi_enter(void) { }
 156 static inline void printk_nmi_exit(void) { }
 157 static inline void printk_nmi_direct_enter(void) { }
 158 static inline void printk_nmi_direct_exit(void) { }
 159 #endif /* PRINTK_NMI */
 160
 161 #ifdef CONFIG_PRINTK
 162 asmlinkage __printf(5, 0)
 163 int vprintk_emit(int facility, int level,
 164                  const char *dict, size_t dictlen,
 165                  const char *fmt, va_list args);
 166
 167 asmlinkage __printf(1, 0)
 168 int vprintk(const char *fmt, va_list args);
 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 asmlinkage void dump_stack(void) __cold;
 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 dump_stack(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 #ifndef pr_fmt
 283 #define pr_fmt(fmt) fmt
 284 #endif
 285
 286 /*
 287  * These can be used to print at the various log levels.
 288  * All of these will print unconditionally, although note that pr_debug()
 289  * and other debug macros are compiled out unless either DEBUG is defined
 290  * or CONFIG_DYNAMIC_DEBUG is set.
 291  */
 292 #define pr_emerg(fmt, ...) \
 293         printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
 294 #define pr_alert(fmt, ...) \
 295         printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
 296 #define pr_crit(fmt, ...) \
 297         printk(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
 298 #define pr_err(fmt, ...) \
 299         printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
 300 #define pr_warn(fmt, ...) \
 301         printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
 302 #define pr_notice(fmt, ...) \
 303         printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
 304 #define pr_info(fmt, ...) \
 305         printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
 306 /*
 307  * Like KERN_CONT, pr_cont() should only be used when continuing
 308  * a line with no newline ('\n') enclosed. Otherwise it defaults
 309  * back to KERN_DEFAULT.
 310  */
 311 #define pr_cont(fmt, ...) \
 312         printk(KERN_CONT fmt, ##__VA_ARGS__)
 313
 314 /* pr_devel() should produce zero code unless DEBUG is defined */
 315 #ifdef DEBUG
 316 #define pr_devel(fmt, ...) \
 317         printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 318 #else
 319 #define pr_devel(fmt, ...) \
 320         no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 321 #endif
 322
 323
 324 /* If you are writing a driver, please use dev_dbg instead */
 325 #if defined(CONFIG_DYNAMIC_DEBUG)
 326 #include <linux/dynamic_debug.h>
 327
 328 /* dynamic_pr_debug() uses pr_fmt() internally so we don't need it here */
 329 #define pr_debug(fmt, ...) \
 330         dynamic_pr_debug(fmt, ##__VA_ARGS__)
 331 #elif defined(DEBUG)
 332 #define pr_debug(fmt, ...) \
 333         printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 334 #else
 335 #define pr_debug(fmt, ...) \
 336         no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 337 #endif
 338
 339 /*
 340  * Print a one-time message (analogous to WARN_ONCE() et al):
 341  */
 342
 343 #ifdef CONFIG_PRINTK
 344 #define printk_once(fmt, ...)                                   \
 345 ({                                                              \
 346         static bool __section(.data.once) __print_once;         \
 347         bool __ret_print_once = !__print_once;                  \
 348                                                                 \
 349         if (!__print_once) {                                    \
 350                 __print_once = true;                            \
 351                 printk(fmt, ##__VA_ARGS__);                     \
 352         }                                                       \
 353         unlikely(__ret_print_once);                             \
 354 })
 355 #define printk_deferred_once(fmt, ...)                          \
 356 ({                                                              \
 357         static bool __section(.data.once) __print_once;         \
 358         bool __ret_print_once = !__print_once;                  \
 359                                                                 \
 360         if (!__print_once) {                                    \
 361                 __print_once = true;                            \
 362                 printk_deferred(fmt, ##__VA_ARGS__);            \
 363         }                                                       \
 364         unlikely(__ret_print_once);                             \
 365 })
 366 #else
 367 #define printk_once(fmt, ...)                                   \
 368         no_printk(fmt, ##__VA_ARGS__)
 369 #define printk_deferred_once(fmt, ...)                          \
 370         no_printk(fmt, ##__VA_ARGS__)
 371 #endif
 372
 373 #define pr_emerg_once(fmt, ...)                                 \
 374         printk_once(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
 375 #define pr_alert_once(fmt, ...)                                 \
 376         printk_once(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
 377 #define pr_crit_once(fmt, ...)                                  \
 378         printk_once(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
 379 #define pr_err_once(fmt, ...)                                   \
 380         printk_once(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
 381 #define pr_warn_once(fmt, ...)                                  \
 382         printk_once(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
 383 #define pr_notice_once(fmt, ...)                                \
 384         printk_once(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
 385 #define pr_info_once(fmt, ...)                                  \
 386         printk_once(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
 387 #define pr_cont_once(fmt, ...)                                  \
 388         printk_once(KERN_CONT pr_fmt(fmt), ##__VA_ARGS__)
 389
 390 #if defined(DEBUG)
 391 #define pr_devel_once(fmt, ...)                                 \
 392         printk_once(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 393 #else
 394 #define pr_devel_once(fmt, ...)                                 \
 395         no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 396 #endif
 397
 398 /* If you are writing a driver, please use dev_dbg instead */
 399 #if defined(DEBUG)
 400 #define pr_debug_once(fmt, ...)                                 \
 401         printk_once(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 402 #else
 403 #define pr_debug_once(fmt, ...)                                 \
 404         no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 405 #endif
 406
 407 /*
 408  * ratelimited messages with local ratelimit_state,
 409  * no local ratelimit_state used in the !PRINTK case
 410  */
 411 #ifdef CONFIG_PRINTK
 412 #define printk_ratelimited(fmt, ...)                                    \
 413 ({                                                                      \
 414         static DEFINE_RATELIMIT_STATE(_rs,                              \
 415                                       DEFAULT_RATELIMIT_INTERVAL,       \
 416                                       DEFAULT_RATELIMIT_BURST);         \
 417                                                                         \
 418         if (__ratelimit(&_rs))                                          \
 419                 printk(fmt, ##__VA_ARGS__);                             \
 420 })
 421 #else
 422 #define printk_ratelimited(fmt, ...)                                    \
 423         no_printk(fmt, ##__VA_ARGS__)
 424 #endif
 425
 426 #define pr_emerg_ratelimited(fmt, ...)                                  \
 427         printk_ratelimited(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
 428 #define pr_alert_ratelimited(fmt, ...)                                  \
 429         printk_ratelimited(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
 430 #define pr_crit_ratelimited(fmt, ...)                                   \
 431         printk_ratelimited(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
 432 #define pr_err_ratelimited(fmt, ...)                                    \
 433         printk_ratelimited(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
 434 #define pr_warn_ratelimited(fmt, ...)                                   \
 435         printk_ratelimited(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
 436 #define pr_notice_ratelimited(fmt, ...)                                 \
 437         printk_ratelimited(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
 438 #define pr_info_ratelimited(fmt, ...)                                   \
 439         printk_ratelimited(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
 440 /* no pr_cont_ratelimited, don't do that... */
 441
 442 #if defined(DEBUG)
 443 #define pr_devel_ratelimited(fmt, ...)                                  \
 444         printk_ratelimited(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 445 #else
 446 #define pr_devel_ratelimited(fmt, ...)                                  \
 447         no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 448 #endif
 449
 450 /* If you are writing a driver, please use dev_dbg instead */
 451 #if defined(CONFIG_DYNAMIC_DEBUG)
 452 /* descriptor check is first to prevent flooding with "callbacks suppressed" */
 453 #define pr_debug_ratelimited(fmt, ...)                                  \
 454 do {                                                                    \
 455         static DEFINE_RATELIMIT_STATE(_rs,                              \
 456                                       DEFAULT_RATELIMIT_INTERVAL,       \
 457                                       DEFAULT_RATELIMIT_BURST);         \
 458         DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, pr_fmt(fmt));         \
 459         if (DYNAMIC_DEBUG_BRANCH(descriptor) &&                         \
 460             __ratelimit(&_rs))                                          \
 461                 __dynamic_pr_debug(&descriptor, pr_fmt(fmt), ##__VA_ARGS__);    \
 462 } while (0)
 463 #elif defined(DEBUG)
 464 #define pr_debug_ratelimited(fmt, ...)                                  \
 465         printk_ratelimited(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 466 #else
 467 #define pr_debug_ratelimited(fmt, ...) \
 468         no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 469 #endif
 470
 471 extern const struct file_operations kmsg_fops;
 472
 473 enum {
 474         DUMP_PREFIX_NONE,
 475         DUMP_PREFIX_ADDRESS,
 476         DUMP_PREFIX_OFFSET
 477 };
 478 extern int hex_dump_to_buffer(const void *buf, size_t len, int rowsize,
 479                               int groupsize, char *linebuf, size_t linebuflen,
 480                               bool ascii);
 481 #ifdef CONFIG_PRINTK
 482 extern void print_hex_dump(const char *level, const char *prefix_str,
 483                            int prefix_type, int rowsize, int groupsize,
 484                            const void *buf, size_t len, bool ascii);
 485 #else
 486 static inline void print_hex_dump(const char *level, const char *prefix_str,
 487                                   int prefix_type, int rowsize, int groupsize,
 488                                   const void *buf, size_t len, bool ascii)
 489 {
 490 }
 491 static inline void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
 492                                         const void *buf, size_t len)
 493 {
 494 }
 495
 496 #endif
 497
 498 #if defined(CONFIG_DYNAMIC_DEBUG)
 499 #define print_hex_dump_debug(prefix_str, prefix_type, rowsize,  \
 500                              groupsize, buf, len, ascii)        \
 501         dynamic_hex_dump(prefix_str, prefix_type, rowsize,      \
 502                          groupsize, buf, len, ascii)
 503 #elif defined(DEBUG)
 504 #define print_hex_dump_debug(prefix_str, prefix_type, rowsize,          \
 505                              groupsize, buf, len, ascii)                \
 506         print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, rowsize,    \
 507                        groupsize, buf, len, ascii)
 508 #else
 509 static inline void print_hex_dump_debug(const char *prefix_str, int prefix_type,
 510                                         int rowsize, int groupsize,
 511                                         const void *buf, size_t len, bool ascii)
 512 {
 513 }
 514 #endif
 515
 516 /**
 517  * print_hex_dump_bytes - shorthand form of print_hex_dump() with default params
 518  * @prefix_str: string to prefix each line with;
 519  *  caller supplies trailing spaces for alignment if desired
 520  * @prefix_type: controls whether prefix of an offset, address, or none
 521  *  is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE)
 522  * @buf: data blob to dump
 523  * @len: number of bytes in the @buf
 524  *
 525  * Calls print_hex_dump(), with log level of KERN_DEBUG,
 526  * rowsize of 16, groupsize of 1, and ASCII output included.
 527  */
 528 #define print_hex_dump_bytes(prefix_str, prefix_type, buf, len) \
 529         print_hex_dump_debug(prefix_str, prefix_type, 16, 1, buf, len, true)
 530
 531 #endif