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_DEBUG  10 /* issue debug messages */
  54 #define CONSOLE_LOGLEVEL_MOTORMOUTH 15  /* You can't shut this one up */
  55
  56 /*
  57  * Default used to be hard-coded at 7, quiet used to be hardcoded at 4,
  58  * we're now allowing both to be set from kernel config.
  59  */
  60 #define CONSOLE_LOGLEVEL_DEFAULT CONFIG_CONSOLE_LOGLEVEL_DEFAULT
  61 #define CONSOLE_LOGLEVEL_QUIET   CONFIG_CONSOLE_LOGLEVEL_QUIET
  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 asmlinkage void dump_stack(void) __cold;
 209 extern void printk_safe_init(void);
 210 extern void printk_safe_flush(void);
 211 extern void printk_safe_flush_on_panic(void);
 212 #else
 213 static inline __printf(1, 0)
 214 int vprintk(const char *s, va_list args)
 215 {
 216         return 0;
 217 }
 218 static inline __printf(1, 2) __cold
 219 int printk(const char *s, ...)
 220 {
 221         return 0;
 222 }
 223 static inline __printf(1, 2) __cold
 224 int printk_deferred(const char *s, ...)
 225 {
 226         return 0;
 227 }
 228 static inline int printk_ratelimit(void)
 229 {
 230         return 0;
 231 }
 232 static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies,
 233                                           unsigned int interval_msec)
 234 {
 235         return false;
 236 }
 237
 238 static inline void wake_up_klogd(void)
 239 {
 240 }
 241
 242 static inline char *log_buf_addr_get(void)
 243 {
 244         return NULL;
 245 }
 246
 247 static inline u32 log_buf_len_get(void)
 248 {
 249         return 0;
 250 }
 251
 252 static inline void log_buf_vmcoreinfo_setup(void)
 253 {
 254 }
 255
 256 static inline void setup_log_buf(int early)
 257 {
 258 }
 259
 260 static inline __printf(1, 2) void dump_stack_set_arch_desc(const char *fmt, ...)
 261 {
 262 }
 263
 264 static inline void dump_stack_print_info(const char *log_lvl)
 265 {
 266 }
 267
 268 static inline void show_regs_print_info(const char *log_lvl)
 269 {
 270 }
 271
 272 static inline asmlinkage void dump_stack(void)
 273 {
 274 }
 275
 276 static inline void printk_safe_init(void)
 277 {
 278 }
 279
 280 static inline void printk_safe_flush(void)
 281 {
 282 }
 283
 284 static inline void printk_safe_flush_on_panic(void)
 285 {
 286 }
 287 #endif
 288
 289 extern int kptr_restrict;
 290
 291 #ifndef pr_fmt
 292 #define pr_fmt(fmt) fmt
 293 #endif
 294
 295 /*
 296  * These can be used to print at the various log levels.
 297  * All of these will print unconditionally, although note that pr_debug()
 298  * and other debug macros are compiled out unless either DEBUG is defined
 299  * or CONFIG_DYNAMIC_DEBUG is set.
 300  */
 301 #define pr_emerg(fmt, ...) \
 302         printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
 303 #define pr_alert(fmt, ...) \
 304         printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
 305 #define pr_crit(fmt, ...) \
 306         printk(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
 307 #define pr_err(fmt, ...) \
 308         printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
 309 #define pr_warning(fmt, ...) \
 310         printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
 311 #define pr_warn pr_warning
 312 #define pr_notice(fmt, ...) \
 313         printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
 314 #define pr_info(fmt, ...) \
 315         printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
 316 /*
 317  * Like KERN_CONT, pr_cont() should only be used when continuing
 318  * a line with no newline ('\n') enclosed. Otherwise it defaults
 319  * back to KERN_DEFAULT.
 320  */
 321 #define pr_cont(fmt, ...) \
 322         printk(KERN_CONT fmt, ##__VA_ARGS__)
 323
 324 /* pr_devel() should produce zero code unless DEBUG is defined */
 325 #ifdef DEBUG
 326 #define pr_devel(fmt, ...) \
 327         printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 328 #else
 329 #define pr_devel(fmt, ...) \
 330         no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 331 #endif
 332
 333
 334 /* If you are writing a driver, please use dev_dbg instead */
 335 #if defined(CONFIG_DYNAMIC_DEBUG)
 336 #include <linux/dynamic_debug.h>
 337
 338 /* dynamic_pr_debug() uses pr_fmt() internally so we don't need it here */
 339 #define pr_debug(fmt, ...) \
 340         dynamic_pr_debug(fmt, ##__VA_ARGS__)
 341 #elif defined(DEBUG)
 342 #define pr_debug(fmt, ...) \
 343         printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 344 #else
 345 #define pr_debug(fmt, ...) \
 346         no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 347 #endif
 348
 349 /*
 350  * Print a one-time message (analogous to WARN_ONCE() et al):
 351  */
 352
 353 #ifdef CONFIG_PRINTK
 354 #define printk_once(fmt, ...)                                   \
 355 ({                                                              \
 356         static bool __print_once __read_mostly;                 \
 357         bool __ret_print_once = !__print_once;                  \
 358                                                                 \
 359         if (!__print_once) {                                    \
 360                 __print_once = true;                            \
 361                 printk(fmt, ##__VA_ARGS__);                     \
 362         }                                                       \
 363         unlikely(__ret_print_once);                             \
 364 })
 365 #define printk_deferred_once(fmt, ...)                          \
 366 ({                                                              \
 367         static bool __print_once __read_mostly;                 \
 368         bool __ret_print_once = !__print_once;                  \
 369                                                                 \
 370         if (!__print_once) {                                    \
 371                 __print_once = true;                            \
 372                 printk_deferred(fmt, ##__VA_ARGS__);            \
 373         }                                                       \
 374         unlikely(__ret_print_once);                             \
 375 })
 376 #else
 377 #define printk_once(fmt, ...)                                   \
 378         no_printk(fmt, ##__VA_ARGS__)
 379 #define printk_deferred_once(fmt, ...)                          \
 380         no_printk(fmt, ##__VA_ARGS__)
 381 #endif
 382
 383 #define pr_emerg_once(fmt, ...)                                 \
 384         printk_once(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
 385 #define pr_alert_once(fmt, ...)                                 \
 386         printk_once(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
 387 #define pr_crit_once(fmt, ...)                                  \
 388         printk_once(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
 389 #define pr_err_once(fmt, ...)                                   \
 390         printk_once(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
 391 #define pr_warn_once(fmt, ...)                                  \
 392         printk_once(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
 393 #define pr_notice_once(fmt, ...)                                \
 394         printk_once(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
 395 #define pr_info_once(fmt, ...)                                  \
 396         printk_once(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
 397 #define pr_cont_once(fmt, ...)                                  \
 398         printk_once(KERN_CONT pr_fmt(fmt), ##__VA_ARGS__)
 399
 400 #if defined(DEBUG)
 401 #define pr_devel_once(fmt, ...)                                 \
 402         printk_once(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 403 #else
 404 #define pr_devel_once(fmt, ...)                                 \
 405         no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 406 #endif
 407
 408 /* If you are writing a driver, please use dev_dbg instead */
 409 #if defined(DEBUG)
 410 #define pr_debug_once(fmt, ...)                                 \
 411         printk_once(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 412 #else
 413 #define pr_debug_once(fmt, ...)                                 \
 414         no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 415 #endif
 416
 417 /*
 418  * ratelimited messages with local ratelimit_state,
 419  * no local ratelimit_state used in the !PRINTK case
 420  */
 421 #ifdef CONFIG_PRINTK
 422 #define printk_ratelimited(fmt, ...)                                    \
 423 ({                                                                      \
 424         static DEFINE_RATELIMIT_STATE(_rs,                              \
 425                                       DEFAULT_RATELIMIT_INTERVAL,       \
 426                                       DEFAULT_RATELIMIT_BURST);         \
 427                                                                         \
 428         if (__ratelimit(&_rs))                                          \
 429                 printk(fmt, ##__VA_ARGS__);                             \
 430 })
 431 #else
 432 #define printk_ratelimited(fmt, ...)                                    \
 433         no_printk(fmt, ##__VA_ARGS__)
 434 #endif
 435
 436 #define pr_emerg_ratelimited(fmt, ...)                                  \
 437         printk_ratelimited(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
 438 #define pr_alert_ratelimited(fmt, ...)                                  \
 439         printk_ratelimited(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
 440 #define pr_crit_ratelimited(fmt, ...)                                   \
 441         printk_ratelimited(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
 442 #define pr_err_ratelimited(fmt, ...)                                    \
 443         printk_ratelimited(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
 444 #define pr_warn_ratelimited(fmt, ...)                                   \
 445         printk_ratelimited(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
 446 #define pr_notice_ratelimited(fmt, ...)                                 \
 447         printk_ratelimited(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
 448 #define pr_info_ratelimited(fmt, ...)                                   \
 449         printk_ratelimited(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
 450 /* no pr_cont_ratelimited, don't do that... */
 451
 452 #if defined(DEBUG)
 453 #define pr_devel_ratelimited(fmt, ...)                                  \
 454         printk_ratelimited(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 455 #else
 456 #define pr_devel_ratelimited(fmt, ...)                                  \
 457         no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 458 #endif
 459
 460 /* If you are writing a driver, please use dev_dbg instead */
 461 #if defined(CONFIG_DYNAMIC_DEBUG)
 462 /* descriptor check is first to prevent flooding with "callbacks suppressed" */
 463 #define pr_debug_ratelimited(fmt, ...)                                  \
 464 do {                                                                    \
 465         static DEFINE_RATELIMIT_STATE(_rs,                              \
 466                                       DEFAULT_RATELIMIT_INTERVAL,       \
 467                                       DEFAULT_RATELIMIT_BURST);         \
 468         DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, pr_fmt(fmt));         \
 469         if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT) &&        \
 470             __ratelimit(&_rs))                                          \
 471                 __dynamic_pr_debug(&descriptor, pr_fmt(fmt), ##__VA_ARGS__);    \
 472 } while (0)
 473 #elif defined(DEBUG)
 474 #define pr_debug_ratelimited(fmt, ...)                                  \
 475         printk_ratelimited(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 476 #else
 477 #define pr_debug_ratelimited(fmt, ...) \
 478         no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 479 #endif
 480
 481 extern const struct file_operations kmsg_fops;
 482
 483 enum {
 484         DUMP_PREFIX_NONE,
 485         DUMP_PREFIX_ADDRESS,
 486         DUMP_PREFIX_OFFSET
 487 };
 488 extern int hex_dump_to_buffer(const void *buf, size_t len, int rowsize,
 489                               int groupsize, char *linebuf, size_t linebuflen,
 490                               bool ascii);
 491 #ifdef CONFIG_PRINTK
 492 extern void print_hex_dump(const char *level, const char *prefix_str,
 493                            int prefix_type, int rowsize, int groupsize,
 494                            const void *buf, size_t len, bool ascii);
 495 #if defined(CONFIG_DYNAMIC_DEBUG)
 496 #define print_hex_dump_bytes(prefix_str, prefix_type, buf, len) \
 497         dynamic_hex_dump(prefix_str, prefix_type, 16, 1, buf, len, true)
 498 #else
 499 extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
 500                                  const void *buf, size_t len);
 501 #endif /* defined(CONFIG_DYNAMIC_DEBUG) */
 502 #else
 503 static inline void print_hex_dump(const char *level, const char *prefix_str,
 504                                   int prefix_type, int rowsize, int groupsize,
 505                                   const void *buf, size_t len, bool ascii)
 506 {
 507 }
 508 static inline void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
 509                                         const void *buf, size_t len)
 510 {
 511 }
 512
 513 #endif
 514
 515 #if defined(CONFIG_DYNAMIC_DEBUG)
 516 #define print_hex_dump_debug(prefix_str, prefix_type, rowsize,  \
 517                              groupsize, buf, len, ascii)        \
 518         dynamic_hex_dump(prefix_str, prefix_type, rowsize,      \
 519                          groupsize, buf, len, ascii)
 520 #elif defined(DEBUG)
 521 #define print_hex_dump_debug(prefix_str, prefix_type, rowsize,          \
 522                              groupsize, buf, len, ascii)                \
 523         print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, rowsize,    \
 524                        groupsize, buf, len, ascii)
 525 #else
 526 static inline void print_hex_dump_debug(const char *prefix_str, int prefix_type,
 527                                         int rowsize, int groupsize,
 528                                         const void *buf, size_t len, bool ascii)
 529 {
 530 }
 531 #endif
 532
 533 #endif