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        do {                                            \
 136                if (0)                                  \
 137                        printk(fmt, ##__VA_ARGS__);     \
 138        } while (0);                                    \
 139        0;                                              \
 140})
 141
 142#ifdef CONFIG_EARLY_PRINTK
 143extern asmlinkage __printf(1, 2)
 144void early_printk(const char *fmt, ...);
 145#else
 146static inline __printf(1, 2) __cold
 147void early_printk(const char *s, ...) { }
 148#endif
 149
 150#ifdef CONFIG_PRINTK_NMI
 151extern void printk_nmi_enter(void);
 152extern void printk_nmi_exit(void);
 153#else
 154static inline void printk_nmi_enter(void) { }
 155static inline void printk_nmi_exit(void) { }
 156#endif /* PRINTK_NMI */
 157
 158#ifdef CONFIG_PRINTK
 159asmlinkage __printf(5, 0)
 160int vprintk_emit(int facility, int level,
 161                 const char *dict, size_t dictlen,
 162                 const char *fmt, va_list args);
 163
 164asmlinkage __printf(1, 0)
 165int vprintk(const char *fmt, va_list args);
 166
 167asmlinkage __printf(5, 6) __cold
 168int printk_emit(int facility, int level,
 169                const char *dict, size_t dictlen,
 170                const char *fmt, ...);
 171
 172asmlinkage __printf(1, 2) __cold
 173int 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 */
 185extern int __printk_ratelimit(const char *func);
 186#define printk_ratelimit() __printk_ratelimit(__func__)
 187extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
 188                                   unsigned int interval_msec);
 189
 190extern int printk_delay_msec;
 191extern int dmesg_restrict;
 192extern int kptr_restrict;
 193
 194extern int
 195devkmsg_sysctl_set_loglvl(struct ctl_table *table, int write, void __user *buf,
 196                          size_t *lenp, loff_t *ppos);
 197
 198extern void wake_up_klogd(void);
 199
 200char *log_buf_addr_get(void);
 201u32 log_buf_len_get(void);
 202void log_buf_vmcoreinfo_setup(void);
 203void __init setup_log_buf(int early);
 204__printf(1, 2) void dump_stack_set_arch_desc(const char *fmt, ...);
 205void dump_stack_print_info(const char *log_lvl);
 206void show_regs_print_info(const char *log_lvl);
 207extern void printk_safe_init(void);
 208extern void printk_safe_flush(void);
 209extern void printk_safe_flush_on_panic(void);
 210#else
 211static inline __printf(1, 0)
 212int vprintk(const char *s, va_list args)
 213{
 214        return 0;
 215}
 216static inline __printf(1, 2) __cold
 217int printk(const char *s, ...)
 218{
 219        return 0;
 220}
 221static inline __printf(1, 2) __cold
 222int printk_deferred(const char *s, ...)
 223{
 224        return 0;
 225}
 226static inline int printk_ratelimit(void)
 227{
 228        return 0;
 229}
 230static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies,
 231                                          unsigned int interval_msec)
 232{
 233        return false;
 234}
 235
 236static inline void wake_up_klogd(void)
 237{
 238}
 239
 240static inline char *log_buf_addr_get(void)
 241{
 242        return NULL;
 243}
 244
 245static inline u32 log_buf_len_get(void)
 246{
 247        return 0;
 248}
 249
 250static inline void log_buf_vmcoreinfo_setup(void)
 251{
 252}
 253
 254static inline void setup_log_buf(int early)
 255{
 256}
 257
 258static inline __printf(1, 2) void dump_stack_set_arch_desc(const char *fmt, ...)
 259{
 260}
 261
 262static inline void dump_stack_print_info(const char *log_lvl)
 263{
 264}
 265
 266static inline void show_regs_print_info(const char *log_lvl)
 267{
 268}
 269
 270static inline void printk_safe_init(void)
 271{
 272}
 273
 274static inline void printk_safe_flush(void)
 275{
 276}
 277
 278static inline void printk_safe_flush_on_panic(void)
 279{
 280}
 281#endif
 282
 283extern 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, ...)                                  \
 458do {                                                                    \
 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
 475extern const struct file_operations kmsg_fops;
 476
 477enum {
 478        DUMP_PREFIX_NONE,
 479        DUMP_PREFIX_ADDRESS,
 480        DUMP_PREFIX_OFFSET
 481};
 482extern 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
 486extern 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
 493extern 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
 497static 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}
 502static 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
 520static 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
 528