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