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 'd':       /* KERN_DEFAULT */
  22                case 'c':       /* KERN_CONT */
  23                        return buffer[1];
  24                }
  25        }
  26        return 0;
  27}
  28
  29static 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
  37static 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
  63extern 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
  70static inline void console_silent(void)
  71{
  72        console_loglevel = CONSOLE_LOGLEVEL_SILENT;
  73}
  74
  75static 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
  83extern char devkmsg_log_str[];
  84struct ctl_table;
  85
  86struct 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
 141extern asmlinkage __printf(1, 2)
 142void early_printk(const char *fmt, ...);
 143#else
 144static inline __printf(1, 2) __cold
 145void early_printk(const char *s, ...) { }
 146#endif
 147
 148#ifdef CONFIG_PRINTK_NMI
 149extern void printk_nmi_enter(void);
 150extern void printk_nmi_exit(void);
 151#else
 152static inline void printk_nmi_enter(void) { }
 153static inline void printk_nmi_exit(void) { }
 154#endif /* PRINTK_NMI */
 155
 156#ifdef CONFIG_PRINTK
 157asmlinkage __printf(5, 0)
 158int vprintk_emit(int facility, int level,
 159                 const char *dict, size_t dictlen,
 160                 const char *fmt, va_list args);
 161
 162asmlinkage __printf(1, 0)
 163int vprintk(const char *fmt, va_list args);
 164
 165asmlinkage __printf(5, 6) __cold
 166int printk_emit(int facility, int level,
 167                const char *dict, size_t dictlen,
 168                const char *fmt, ...);
 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 void printk_safe_init(void);
 205extern void printk_safe_flush(void);
 206extern void printk_safe_flush_on_panic(void);
 207#else
 208static inline __printf(1, 0)
 209int vprintk(const char *s, va_list args)
 210{
 211        return 0;
 212}
 213static inline __printf(1, 2) __cold
 214int printk(const char *s, ...)
 215{
 216        return 0;
 217}
 218static inline __printf(1, 2) __cold
 219int printk_deferred(const char *s, ...)
 220{
 221        return 0;
 222}
 223static inline int printk_ratelimit(void)
 224{
 225        return 0;
 226}
 227static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies,
 228                                          unsigned int interval_msec)
 229{
 230        return false;
 231}
 232
 233static inline void wake_up_klogd(void)
 234{
 235}
 236
 237static inline char *log_buf_addr_get(void)
 238{
 239        return NULL;
 240}
 241
 242static inline u32 log_buf_len_get(void)
 243{
 244        return 0;
 245}
 246
 247static inline void log_buf_vmcoreinfo_setup(void)
 248{
 249}
 250
 251static inline void setup_log_buf(int early)
 252{
 253}
 254
 255static inline __printf(1, 2) void dump_stack_set_arch_desc(const char *fmt, ...)
 256{
 257}
 258
 259static inline void dump_stack_print_info(const char *log_lvl)
 260{
 261}
 262
 263static inline void show_regs_print_info(const char *log_lvl)
 264{
 265}
 266
 267static inline void printk_safe_init(void)
 268{
 269}
 270
 271static inline void printk_safe_flush(void)
 272{
 273}
 274
 275static inline void printk_safe_flush_on_panic(void)
 276{
 277}
 278#endif
 279
 280extern int kptr_restrict;
 281
 282extern asmlinkage void dump_stack(void) __cold;
 283
 284#ifndef pr_fmt
 285#define pr_fmt(fmt) fmt
 286#endif
 287
 288/*
 289 * These can be used to print at the various log levels.
 290 * All of these will print unconditionally, although note that pr_debug()
 291 * and other debug macros are compiled out unless either DEBUG is defined
 292 * or CONFIG_DYNAMIC_DEBUG is set.
 293 */
 294#define pr_emerg(fmt, ...) \
 295        printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
 296#define pr_alert(fmt, ...) \
 297        printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
 298#define pr_crit(fmt, ...) \
 299        printk(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
 300#define pr_err(fmt, ...) \
 301        printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
 302#define pr_warning(fmt, ...) \
 303        printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
 304#define pr_warn pr_warning
 305#define pr_notice(fmt, ...) \
 306        printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
 307#define pr_info(fmt, ...) \
 308        printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
 309/*
 310 * Like KERN_CONT, pr_cont() should only be used when continuing
 311 * a line with no newline ('\n') enclosed. Otherwise it defaults
 312 * back to KERN_DEFAULT.
 313 */
 314#define pr_cont(fmt, ...) \
 315        printk(KERN_CONT fmt, ##__VA_ARGS__)
 316
 317/* pr_devel() should produce zero code unless DEBUG is defined */
 318#ifdef DEBUG
 319#define pr_devel(fmt, ...) \
 320        printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 321#else
 322#define pr_devel(fmt, ...) \
 323        no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 324#endif
 325
 326
 327/* If you are writing a driver, please use dev_dbg instead */
 328#if defined(CONFIG_DYNAMIC_DEBUG)
 329#include <linux/dynamic_debug.h>
 330
 331/* dynamic_pr_debug() uses pr_fmt() internally so we don't need it here */
 332#define pr_debug(fmt, ...) \
 333        dynamic_pr_debug(fmt, ##__VA_ARGS__)
 334#elif defined(DEBUG)
 335#define pr_debug(fmt, ...) \
 336        printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 337#else
 338#define pr_debug(fmt, ...) \
 339        no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 340#endif
 341
 342/*
 343 * Print a one-time message (analogous to WARN_ONCE() et al):
 344 */
 345
 346#ifdef CONFIG_PRINTK
 347#define printk_once(fmt, ...)                                   \
 348({                                                              \
 349        static bool __print_once __read_mostly;                 \
 350        bool __ret_print_once = !__print_once;                  \
 351                                                                \
 352        if (!__print_once) {                                    \
 353                __print_once = true;                            \
 354                printk(fmt, ##__VA_ARGS__);                     \
 355        }                                                       \
 356        unlikely(__ret_print_once);                             \
 357})
 358#define printk_deferred_once(fmt, ...)                          \
 359({                                                              \
 360        static bool __print_once __read_mostly;                 \
 361        bool __ret_print_once = !__print_once;                  \
 362                                                                \
 363        if (!__print_once) {                                    \
 364                __print_once = true;                            \
 365                printk_deferred(fmt, ##__VA_ARGS__);            \
 366        }                                                       \
 367        unlikely(__ret_print_once);                             \
 368})
 369#else
 370#define printk_once(fmt, ...)                                   \
 371        no_printk(fmt, ##__VA_ARGS__)
 372#define printk_deferred_once(fmt, ...)                          \
 373        no_printk(fmt, ##__VA_ARGS__)
 374#endif
 375
 376#define pr_emerg_once(fmt, ...)                                 \
 377        printk_once(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
 378#define pr_alert_once(fmt, ...)                                 \
 379        printk_once(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
 380#define pr_crit_once(fmt, ...)                                  \
 381        printk_once(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
 382#define pr_err_once(fmt, ...)                                   \
 383        printk_once(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
 384#define pr_warn_once(fmt, ...)                                  \
 385        printk_once(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
 386#define pr_notice_once(fmt, ...)                                \
 387        printk_once(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
 388#define pr_info_once(fmt, ...)                                  \
 389        printk_once(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
 390#define pr_cont_once(fmt, ...)                                  \
 391        printk_once(KERN_CONT pr_fmt(fmt), ##__VA_ARGS__)
 392
 393#if defined(DEBUG)
 394#define pr_devel_once(fmt, ...)                                 \
 395        printk_once(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 396#else
 397#define pr_devel_once(fmt, ...)                                 \
 398        no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 399#endif
 400
 401/* If you are writing a driver, please use dev_dbg instead */
 402#if defined(DEBUG)
 403#define pr_debug_once(fmt, ...)                                 \
 404        printk_once(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 405#else
 406#define pr_debug_once(fmt, ...)                                 \
 407        no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 408#endif
 409
 410/*
 411 * ratelimited messages with local ratelimit_state,
 412 * no local ratelimit_state used in the !PRINTK case
 413 */
 414#ifdef CONFIG_PRINTK
 415#define printk_ratelimited(fmt, ...)                                    \
 416({                                                                      \
 417        static DEFINE_RATELIMIT_STATE(_rs,                              \
 418                                      DEFAULT_RATELIMIT_INTERVAL,       \
 419                                      DEFAULT_RATELIMIT_BURST);         \
 420                                                                        \
 421        if (__ratelimit(&_rs))                                          \
 422                printk(fmt, ##__VA_ARGS__);                             \
 423})
 424#else
 425#define printk_ratelimited(fmt, ...)                                    \
 426        no_printk(fmt, ##__VA_ARGS__)
 427#endif
 428
 429#define pr_emerg_ratelimited(fmt, ...)                                  \
 430        printk_ratelimited(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
 431#define pr_alert_ratelimited(fmt, ...)                                  \
 432        printk_ratelimited(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
 433#define pr_crit_ratelimited(fmt, ...)                                   \
 434        printk_ratelimited(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
 435#define pr_err_ratelimited(fmt, ...)                                    \
 436        printk_ratelimited(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
 437#define pr_warn_ratelimited(fmt, ...)                                   \
 438        printk_ratelimited(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
 439#define pr_notice_ratelimited(fmt, ...)                                 \
 440        printk_ratelimited(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
 441#define pr_info_ratelimited(fmt, ...)                                   \
 442        printk_ratelimited(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
 443/* no pr_cont_ratelimited, don't do that... */
 444
 445#if defined(DEBUG)
 446#define pr_devel_ratelimited(fmt, ...)                                  \
 447        printk_ratelimited(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 448#else
 449#define pr_devel_ratelimited(fmt, ...)                                  \
 450        no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 451#endif
 452
 453/* If you are writing a driver, please use dev_dbg instead */
 454#if defined(CONFIG_DYNAMIC_DEBUG)
 455/* descriptor check is first to prevent flooding with "callbacks suppressed" */
 456#define pr_debug_ratelimited(fmt, ...)                                  \
 457do {                                                                    \
 458        static DEFINE_RATELIMIT_STATE(_rs,                              \
 459                                      DEFAULT_RATELIMIT_INTERVAL,       \
 460                                      DEFAULT_RATELIMIT_BURST);         \
 461        DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, pr_fmt(fmt));         \
 462        if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT) &&        \
 463            __ratelimit(&_rs))                                          \
 464                __dynamic_pr_debug(&descriptor, pr_fmt(fmt), ##__VA_ARGS__);    \
 465} while (0)
 466#elif defined(DEBUG)
 467#define pr_debug_ratelimited(fmt, ...)                                  \
 468        printk_ratelimited(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 469#else
 470#define pr_debug_ratelimited(fmt, ...) \
 471        no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 472#endif
 473
 474extern const struct file_operations kmsg_fops;
 475
 476enum {
 477        DUMP_PREFIX_NONE,
 478        DUMP_PREFIX_ADDRESS,
 479        DUMP_PREFIX_OFFSET
 480};
 481extern int hex_dump_to_buffer(const void *buf, size_t len, int rowsize,
 482                              int groupsize, char *linebuf, size_t linebuflen,
 483                              bool ascii);
 484#ifdef CONFIG_PRINTK
 485extern void print_hex_dump(const char *level, const char *prefix_str,
 486                           int prefix_type, int rowsize, int groupsize,
 487                           const void *buf, size_t len, bool ascii);
 488#if defined(CONFIG_DYNAMIC_DEBUG)
 489#define print_hex_dump_bytes(prefix_str, prefix_type, buf, len) \
 490        dynamic_hex_dump(prefix_str, prefix_type, 16, 1, buf, len, true)
 491#else
 492extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
 493                                 const void *buf, size_t len);
 494#endif /* defined(CONFIG_DYNAMIC_DEBUG) */
 495#else
 496static inline void print_hex_dump(const char *level, const char *prefix_str,
 497                                  int prefix_type, int rowsize, int groupsize,
 498                                  const void *buf, size_t len, bool ascii)
 499{
 500}
 501static inline void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
 502                                        const void *buf, size_t len)
 503{
 504}
 505
 506#endif
 507
 508#if defined(CONFIG_DYNAMIC_DEBUG)
 509#define print_hex_dump_debug(prefix_str, prefix_type, rowsize,  \
 510                             groupsize, buf, len, ascii)        \
 511        dynamic_hex_dump(prefix_str, prefix_type, rowsize,      \
 512                         groupsize, buf, len, ascii)
 513#elif defined(DEBUG)
 514#define print_hex_dump_debug(prefix_str, prefix_type, rowsize,          \
 515                             groupsize, buf, len, ascii)                \
 516        print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, rowsize,    \
 517                       groupsize, buf, len, ascii)
 518#else
 519static inline void print_hex_dump_debug(const char *prefix_str, int prefix_type,
 520                                        int rowsize, int groupsize,
 521                                        const void *buf, size_t len, bool ascii)
 522{
 523}
 524#endif
 525
 526#endif
 527