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