LXR linux/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
  11extern const char linux_banner[];
  12extern const char linux_proc_banner[];
  13
  14#define PRINTK_MAX_SINGLE_HEADER_LEN 2
  15
  16static 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
  28static 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
  36static 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
  62extern 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
  69static inline void console_silent(void)
  70{
  71        console_loglevel = CONSOLE_LOGLEVEL_SILENT;
  72}
  73
  74static 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
  82extern char devkmsg_log_str[];
  83struct ctl_table;
  84
  85extern int suppress_printk;
  86
  87struct 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
 142extern asmlinkage __printf(1, 2)
 143void early_printk(const char *fmt, ...);
 144#else
 145static inline __printf(1, 2) __cold
 146void early_printk(const char *s, ...) { }
 147#endif
 148
 149#ifdef CONFIG_PRINTK_NMI
 150extern void printk_nmi_enter(void);
 151extern void printk_nmi_exit(void);
 152extern void printk_nmi_direct_enter(void);
 153extern void printk_nmi_direct_exit(void);
 154#else
 155static inline void printk_nmi_enter(void) { }
 156static inline void printk_nmi_exit(void) { }
 157static inline void printk_nmi_direct_enter(void) { }
 158static inline void printk_nmi_direct_exit(void) { }
 159#endif /* PRINTK_NMI */
 160
 161#ifdef CONFIG_PRINTK
 162asmlinkage __printf(5, 0)
 163int vprintk_emit(int facility, int level,
 164                 const char *dict, size_t dictlen,
 165                 const char *fmt, va_list args);
 166
 167asmlinkage __printf(1, 0)
 168int vprintk(const char *fmt, va_list args);
 169
 170asmlinkage __printf(1, 2) __cold
 171int 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 */
 183extern int __printk_ratelimit(const char *func);
 184#define printk_ratelimit() __printk_ratelimit(__func__)
 185extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
 186                                   unsigned int interval_msec);
 187
 188extern int printk_delay_msec;
 189extern int dmesg_restrict;
 190
 191extern int
 192devkmsg_sysctl_set_loglvl(struct ctl_table *table, int write, void __user *buf,
 193                          size_t *lenp, loff_t *ppos);
 194
 195extern void wake_up_klogd(void);
 196
 197char *log_buf_addr_get(void);
 198u32 log_buf_len_get(void);
 199void log_buf_vmcoreinfo_setup(void);
 200void __init setup_log_buf(int early);
 201__printf(1, 2) void dump_stack_set_arch_desc(const char *fmt, ...);
 202void dump_stack_print_info(const char *log_lvl);
 203void show_regs_print_info(const char *log_lvl);
 204extern asmlinkage void dump_stack(void) __cold;
 205extern void printk_safe_init(void);
 206extern void printk_safe_flush(void);
 207extern void printk_safe_flush_on_panic(void);
 208#else
 209static inline __printf(1, 0)
 210int vprintk(const char *s, va_list args)
 211{
 212        return 0;
 213}
 214static inline __printf(1, 2) __cold
 215int printk(const char *s, ...)
 216{
 217        return 0;
 218}
 219static inline __printf(1, 2) __cold
 220int printk_deferred(const char *s, ...)
 221{
 222        return 0;
 223}
 224static inline int printk_ratelimit(void)
 225{
 226        return 0;
 227}
 228static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies,
 229                                          unsigned int interval_msec)
 230{
 231        return false;
 232}
 233
 234static inline void wake_up_klogd(void)
 235{
 236}
 237
 238static inline char *log_buf_addr_get(void)
 239{
 240        return NULL;
 241}
 242
 243static inline u32 log_buf_len_get(void)
 244{
 245        return 0;
 246}
 247
 248static inline void log_buf_vmcoreinfo_setup(void)
 249{
 250}
 251
 252static inline void setup_log_buf(int early)
 253{
 254}
 255
 256static inline __printf(1, 2) void dump_stack_set_arch_desc(const char *fmt, ...)
 257{
 258}
 259
 260static inline void dump_stack_print_info(const char *log_lvl)
 261{
 262}
 263
 264static inline void show_regs_print_info(const char *log_lvl)
 265{
 266}
 267
 268static inline void dump_stack(void)
 269{
 270}
 271
 272static inline void printk_safe_init(void)
 273{
 274}
 275
 276static inline void printk_safe_flush(void)
 277{
 278}
 279
 280static inline void printk_safe_flush_on_panic(void)
 281{
 282}
 283#endif
 284
 285extern int kptr_restrict;
 286
 287#ifndef pr_fmt
 288#define pr_fmt(fmt) fmt
 289#endif
 290
 291/*
 292 * These can be used to print at the various log levels.
 293 * All of these will print unconditionally, although note that pr_debug()
 294 * and other debug macros are compiled out unless either DEBUG is defined
 295 * or CONFIG_DYNAMIC_DEBUG is set.
 296 */
 297#define pr_emerg(fmt, ...) \
 298        printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
 299#define pr_alert(fmt, ...) \
 300        printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
 301#define pr_crit(fmt, ...) \
 302        printk(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
 303#define pr_err(fmt, ...) \
 304        printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
 305#define pr_warn(fmt, ...) \
 306        printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
 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 __section(.data.once) __print_once;         \
 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 __section(.data.once) __print_once;         \
 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, ...)                                  \
 459do {                                                                    \
 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 (DYNAMIC_DEBUG_BRANCH(descriptor) &&                         \
 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
 476extern const struct file_operations kmsg_fops;
 477
 478enum {
 479        DUMP_PREFIX_NONE,
 480        DUMP_PREFIX_ADDRESS,
 481        DUMP_PREFIX_OFFSET
 482};
 483extern 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
 487extern 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#else
 491static inline void print_hex_dump(const char *level, const char *prefix_str,
 492                                  int prefix_type, int rowsize, int groupsize,
 493                                  const void *buf, size_t len, bool ascii)
 494{
 495}
 496static inline void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
 497                                        const void *buf, size_t len)
 498{
 499}
 500
 501#endif
 502
 503#if defined(CONFIG_DYNAMIC_DEBUG)
 504#define print_hex_dump_debug(prefix_str, prefix_type, rowsize,  \
 505                             groupsize, buf, len, ascii)        \
 506        dynamic_hex_dump(prefix_str, prefix_type, rowsize,      \
 507                         groupsize, buf, len, ascii)
 508#elif defined(DEBUG)
 509#define print_hex_dump_debug(prefix_str, prefix_type, rowsize,          \
 510                             groupsize, buf, len, ascii)                \
 511        print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, rowsize,    \
 512                       groupsize, buf, len, ascii)
 513#else
 514static inline void print_hex_dump_debug(const char *prefix_str, int prefix_type,
 515                                        int rowsize, int groupsize,
 516                                        const void *buf, size_t len, bool ascii)
 517{
 518}
 519#endif
 520
 521/**
 522 * print_hex_dump_bytes - shorthand form of print_hex_dump() with default params
 523 * @prefix_str: string to prefix each line with;
 524 *  caller supplies trailing spaces for alignment if desired
 525 * @prefix_type: controls whether prefix of an offset, address, or none
 526 *  is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE)
 527 * @buf: data blob to dump
 528 * @len: number of bytes in the @buf
 529 *
 530 * Calls print_hex_dump(), with log level of KERN_DEBUG,
 531 * rowsize of 16, groupsize of 1, and ASCII output included.
 532 */
 533#define print_hex_dump_bytes(prefix_str, prefix_type, buf, len) \
 534        print_hex_dump_debug(prefix_str, prefix_type, 16, 1, buf, len, true)
 535
 536#endif
 537