/* SPDX-License-Identifier: GPL-2.0 */ #ifndef __KERNEL_PRINTK__ #define __KERNEL_PRINTK__ #include <linux/stdarg.h> #include <linux/init.h> #include <linux/kern_levels.h> #include <linux/linkage.h> #include <linux/ratelimit_types.h> #include <linux/once_lite.h> struct console; extern const char linux_banner[]; extern const char linux_proc_banner[]; extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */ #define PRINTK_MAX_SINGLE_HEADER_LEN … static inline int printk_get_level(const char *buffer) { … } static inline const char *printk_skip_level(const char *buffer) { … } static inline const char *printk_skip_headers(const char *buffer) { … } /* printk's without a loglevel use this.. */ #define MESSAGE_LOGLEVEL_DEFAULT … /* We show everything that is MORE important than this.. */ #define CONSOLE_LOGLEVEL_SILENT … #define CONSOLE_LOGLEVEL_MIN … #define CONSOLE_LOGLEVEL_DEBUG … #define CONSOLE_LOGLEVEL_MOTORMOUTH … /* * Default used to be hard-coded at 7, quiet used to be hardcoded at 4, * we're now allowing both to be set from kernel config. */ #define CONSOLE_LOGLEVEL_DEFAULT … #define CONSOLE_LOGLEVEL_QUIET … int match_devname_and_update_preferred_console(const char *match, const char *name, const short idx); extern int console_printk[]; #define console_loglevel … #define default_message_loglevel … #define minimum_console_loglevel … #define default_console_loglevel … extern void console_verbose(void); /* strlen("ratelimit") + 1 */ #define DEVKMSG_STR_MAX_SIZE … extern char devkmsg_log_str[DEVKMSG_STR_MAX_SIZE]; struct ctl_table; extern int suppress_printk; struct va_format { … }; /* * FW_BUG * Add this to a message where you are sure the firmware is buggy or behaves * really stupid or out of spec. Be aware that the responsible BIOS developer * should be able to fix this issue or at least get a concrete idea of the * problem by reading your message without the need of looking at the kernel * code. * * Use it for definite and high priority BIOS bugs. * * FW_WARN * Use it for not that clear (e.g. could the kernel messed up things already?) * and medium priority BIOS bugs. * * FW_INFO * Use this one if you want to tell the user or vendor about something * suspicious, but generally harmless related to the firmware. * * Use it for information or very low priority BIOS bugs. */ #define FW_BUG … #define FW_WARN … #define FW_INFO … /* * HW_ERR * Add this to a message for hardware errors, so that user can report * it to hardware vendor instead of LKML or software vendor. */ #define HW_ERR … /* * DEPRECATED * Add this to a message whenever you want to warn user space about the use * of a deprecated aspect of an API so they can stop using it */ #define DEPRECATED … /* * Dummy printk for disabled debugging statements to use whilst maintaining * gcc's format checking. */ #define no_printk(fmt, ...) … #ifdef CONFIG_EARLY_PRINTK extern asmlinkage __printf(1, 2) void early_printk(const char *fmt, ...); #else static inline __printf(1, 2) __cold void early_printk(const char *s, ...) { } #endif struct dev_printk_info; #ifdef CONFIG_PRINTK asmlinkage __printf(4, 0) int vprintk_emit(int facility, int level, const struct dev_printk_info *dev_info, const char *fmt, va_list args); asmlinkage __printf(1, 0) int vprintk(const char *fmt, va_list args); asmlinkage __printf(1, 2) __cold int _printk(const char *fmt, ...); /* * Special printk facility for scheduler/timekeeping use only, _DO_NOT_USE_ ! */ __printf(1, 2) __cold int _printk_deferred(const char *fmt, ...); extern void __printk_deferred_enter(void); extern void __printk_deferred_exit(void); /* * The printk_deferred_enter/exit macros are available only as a hack for * some code paths that need to defer all printk console printing. Interrupts * must be disabled for the deferred duration. */ #define printk_deferred_enter() … #define printk_deferred_exit() … /* * Please don't use printk_ratelimit(), because it shares ratelimiting state * with all other unrelated printk_ratelimit() callsites. Instead use * printk_ratelimited() or plain old __ratelimit(). */ extern int __printk_ratelimit(const char *func); #define printk_ratelimit() … extern bool printk_timed_ratelimit(unsigned long *caller_jiffies, unsigned int interval_msec); extern int printk_delay_msec; extern int dmesg_restrict; extern void wake_up_klogd(void); char *log_buf_addr_get(void); u32 log_buf_len_get(void); void log_buf_vmcoreinfo_setup(void); void __init setup_log_buf(int early); __printf(1, 2) void dump_stack_set_arch_desc(const char *fmt, ...); void dump_stack_print_info(const char *log_lvl); void show_regs_print_info(const char *log_lvl); extern asmlinkage void dump_stack_lvl(const char *log_lvl) __cold; extern asmlinkage void dump_stack(void) __cold; void printk_trigger_flush(void); void console_try_replay_all(void); void printk_legacy_allow_panic_sync(void); extern bool nbcon_device_try_acquire(struct console *con); extern void nbcon_device_release(struct console *con); void nbcon_atomic_flush_unsafe(void); #else static inline __printf(1, 0) int vprintk(const char *s, va_list args) { return 0; } static inline __printf(1, 2) __cold int _printk(const char *s, ...) { return 0; } static inline __printf(1, 2) __cold int _printk_deferred(const char *s, ...) { return 0; } static inline void printk_deferred_enter(void) { } static inline void printk_deferred_exit(void) { } static inline int printk_ratelimit(void) { return 0; } static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies, unsigned int interval_msec) { return false; } static inline void wake_up_klogd(void) { } static inline char *log_buf_addr_get(void) { return NULL; } static inline u32 log_buf_len_get(void) { return 0; } static inline void log_buf_vmcoreinfo_setup(void) { } static inline void setup_log_buf(int early) { } static inline __printf(1, 2) void dump_stack_set_arch_desc(const char *fmt, ...) { } static inline void dump_stack_print_info(const char *log_lvl) { } static inline void show_regs_print_info(const char *log_lvl) { } static inline void dump_stack_lvl(const char *log_lvl) { } static inline void dump_stack(void) { } static inline void printk_trigger_flush(void) { } static inline void console_try_replay_all(void) { } static inline void printk_legacy_allow_panic_sync(void) { } static inline bool nbcon_device_try_acquire(struct console *con) { return false; } static inline void nbcon_device_release(struct console *con) { } static inline void nbcon_atomic_flush_unsafe(void) { } #endif bool this_cpu_in_panic(void); #ifdef CONFIG_SMP extern int __printk_cpu_sync_try_get(void); extern void __printk_cpu_sync_wait(void); extern void __printk_cpu_sync_put(void); #else #define __printk_cpu_sync_try_get … #define __printk_cpu_sync_wait … #define __printk_cpu_sync_put … #endif /* CONFIG_SMP */ /** * printk_cpu_sync_get_irqsave() - Disable interrupts and acquire the printk * cpu-reentrant spinning lock. * @flags: Stack-allocated storage for saving local interrupt state, * to be passed to printk_cpu_sync_put_irqrestore(). * * If the lock is owned by another CPU, spin until it becomes available. * Interrupts are restored while spinning. * * CAUTION: This function must be used carefully. It does not behave like a * typical lock. Here are important things to watch out for... * * * This function is reentrant on the same CPU. Therefore the calling * code must not assume exclusive access to data if code accessing the * data can run reentrant or within NMI context on the same CPU. * * * If there exists usage of this function from NMI context, it becomes * unsafe to perform any type of locking or spinning to wait for other * CPUs after calling this function from any context. This includes * using spinlocks or any other busy-waiting synchronization methods. */ #define printk_cpu_sync_get_irqsave(flags) … /** * printk_cpu_sync_put_irqrestore() - Release the printk cpu-reentrant spinning * lock and restore interrupts. * @flags: Caller's saved interrupt state, from printk_cpu_sync_get_irqsave(). */ #define printk_cpu_sync_put_irqrestore(flags) … extern int kptr_restrict; /** * pr_fmt - used by the pr_*() macros to generate the printk format string * @fmt: format string passed from a pr_*() macro * * This macro can be used to generate a unified format string for pr_*() * macros. A common use is to prefix all pr_*() messages in a file with a common * string. For example, defining this at the top of a source file: * * #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt * * would prefix all pr_info, pr_emerg... messages in the file with the module * name. */ #ifndef pr_fmt #define pr_fmt(fmt) … #endif struct module; #ifdef CONFIG_PRINTK_INDEX struct pi_entry { … } __packed; #define __printk_index_emit(_fmt, _level, _subsys_fmt_prefix) … #else /* !CONFIG_PRINTK_INDEX */ #define __printk_index_emit … #endif /* CONFIG_PRINTK_INDEX */ /* * Some subsystems have their own custom printk that applies a va_format to a * generic format, for example, to include a device number or other metadata * alongside the format supplied by the caller. * * In order to store these in the way they would be emitted by the printk * infrastructure, the subsystem provides us with the start, fixed string, and * any subsequent text in the format string. * * We take a variable argument list as pr_fmt/dev_fmt/etc are sometimes passed * as multiple arguments (eg: `"%s: ", "blah"`), and we must only take the * first one. * * subsys_fmt_prefix must be known at compile time, or compilation will fail * (since this is a mistake). If fmt or level is not known at compile time, no * index entry will be made (since this can legitimately happen). */ #define printk_index_subsys_emit(subsys_fmt_prefix, level, fmt, ...) … #define printk_index_wrap(_p_func, _fmt, ...) … /** * printk - print a kernel message * @fmt: format string * * This is printk(). It can be called from any context. We want it to work. * * If printk indexing is enabled, _printk() is called from printk_index_wrap. * Otherwise, printk is simply #defined to _printk. * * We try to grab the console_lock. If we succeed, it's easy - we log the * output and call the console drivers. If we fail to get the semaphore, we * place the output into the log buffer and return. The current holder of * the console_sem will notice the new output in console_unlock(); and will * send it to the consoles before releasing the lock. * * One effect of this deferred printing is that code which calls printk() and * then changes console_loglevel may break. This is because console_loglevel * is inspected when the actual printing occurs. * * See also: * printf(3) * * See the vsnprintf() documentation for format string extensions over C99. */ #define printk(fmt, ...) … #define printk_deferred(fmt, ...) … /** * pr_emerg - Print an emergency-level message * @fmt: format string * @...: arguments for the format string * * This macro expands to a printk with KERN_EMERG loglevel. It uses pr_fmt() to * generate the format string. */ #define pr_emerg(fmt, ...) … /** * pr_alert - Print an alert-level message * @fmt: format string * @...: arguments for the format string * * This macro expands to a printk with KERN_ALERT loglevel. It uses pr_fmt() to * generate the format string. */ #define pr_alert(fmt, ...) … /** * pr_crit - Print a critical-level message * @fmt: format string * @...: arguments for the format string * * This macro expands to a printk with KERN_CRIT loglevel. It uses pr_fmt() to * generate the format string. */ #define pr_crit(fmt, ...) … /** * pr_err - Print an error-level message * @fmt: format string * @...: arguments for the format string * * This macro expands to a printk with KERN_ERR loglevel. It uses pr_fmt() to * generate the format string. */ #define pr_err(fmt, ...) … /** * pr_warn - Print a warning-level message * @fmt: format string * @...: arguments for the format string * * This macro expands to a printk with KERN_WARNING loglevel. It uses pr_fmt() * to generate the format string. */ #define pr_warn(fmt, ...) … /** * pr_notice - Print a notice-level message * @fmt: format string * @...: arguments for the format string * * This macro expands to a printk with KERN_NOTICE loglevel. It uses pr_fmt() to * generate the format string. */ #define pr_notice(fmt, ...) … /** * pr_info - Print an info-level message * @fmt: format string * @...: arguments for the format string * * This macro expands to a printk with KERN_INFO loglevel. It uses pr_fmt() to * generate the format string. */ #define pr_info(fmt, ...) … /** * pr_cont - Continues a previous log message in the same line. * @fmt: format string * @...: arguments for the format string * * This macro expands to a printk with KERN_CONT loglevel. It should only be * used when continuing a log message with no newline ('\n') enclosed. Otherwise * it defaults back to KERN_DEFAULT loglevel. */ #define pr_cont(fmt, ...) … /** * pr_devel - Print a debug-level message conditionally * @fmt: format string * @...: arguments for the format string * * This macro expands to a printk with KERN_DEBUG loglevel if DEBUG is * defined. Otherwise it does nothing. * * It uses pr_fmt() to generate the format string. */ #ifdef DEBUG #define pr_devel … #else #define pr_devel(fmt, ...) … #endif /* If you are writing a driver, please use dev_dbg instead */ #if defined(CONFIG_DYNAMIC_DEBUG) || \ (defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE)) #include <linux/dynamic_debug.h> /** * pr_debug - Print a debug-level message conditionally * @fmt: format string * @...: arguments for the format string * * This macro expands to dynamic_pr_debug() if CONFIG_DYNAMIC_DEBUG is * set. Otherwise, if DEBUG is defined, it's equivalent to a printk with * KERN_DEBUG loglevel. If DEBUG is not defined it does nothing. * * It uses pr_fmt() to generate the format string (dynamic_pr_debug() uses * pr_fmt() internally). */ #define pr_debug(fmt, ...) … #elif defined(DEBUG) #define pr_debug … #else #define pr_debug … #endif /* * Print a one-time message (analogous to WARN_ONCE() et al): */ #ifdef CONFIG_PRINTK #define printk_once(fmt, ...) … #define printk_deferred_once(fmt, ...) … #else #define printk_once … #define printk_deferred_once … #endif #define pr_emerg_once(fmt, ...) … #define pr_alert_once(fmt, ...) … #define pr_crit_once(fmt, ...) … #define pr_err_once(fmt, ...) … #define pr_warn_once(fmt, ...) … #define pr_notice_once(fmt, ...) … #define pr_info_once(fmt, ...) … /* no pr_cont_once, don't do that... */ #if defined(DEBUG) #define pr_devel_once … #else #define pr_devel_once(fmt, ...) … #endif /* If you are writing a driver, please use dev_dbg instead */ #if defined(DEBUG) #define pr_debug_once … #else #define pr_debug_once(fmt, ...) … #endif /* * ratelimited messages with local ratelimit_state, * no local ratelimit_state used in the !PRINTK case */ #ifdef CONFIG_PRINTK #define printk_ratelimited(fmt, ...) … #else #define printk_ratelimited … #endif #define pr_emerg_ratelimited(fmt, ...) … #define pr_alert_ratelimited(fmt, ...) … #define pr_crit_ratelimited(fmt, ...) … #define pr_err_ratelimited(fmt, ...) … #define pr_warn_ratelimited(fmt, ...) … #define pr_notice_ratelimited(fmt, ...) … #define pr_info_ratelimited(fmt, ...) … /* no pr_cont_ratelimited, don't do that... */ #if defined(DEBUG) #define pr_devel_ratelimited … #else #define pr_devel_ratelimited(fmt, ...) … #endif /* If you are writing a driver, please use dev_dbg instead */ #if defined(CONFIG_DYNAMIC_DEBUG) || \ (defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE)) /* descriptor check is first to prevent flooding with "callbacks suppressed" */ #define pr_debug_ratelimited(fmt, ...) … #elif defined(DEBUG) #define pr_debug_ratelimited … #else #define pr_debug_ratelimited … #endif extern const struct file_operations kmsg_fops; enum { … }; extern int hex_dump_to_buffer(const void *buf, size_t len, int rowsize, int groupsize, char *linebuf, size_t linebuflen, bool ascii); #ifdef CONFIG_PRINTK extern void print_hex_dump(const char *level, const char *prefix_str, int prefix_type, int rowsize, int groupsize, const void *buf, size_t len, bool ascii); #else static inline void print_hex_dump(const char *level, const char *prefix_str, int prefix_type, int rowsize, int groupsize, const void *buf, size_t len, bool ascii) { } static inline void print_hex_dump_bytes(const char *prefix_str, int prefix_type, const void *buf, size_t len) { } #endif #if defined(CONFIG_DYNAMIC_DEBUG) || \ (defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE)) #define print_hex_dump_debug(prefix_str, prefix_type, rowsize, \ groupsize, buf, len, ascii) … #elif defined(DEBUG) #define print_hex_dump_debug … #else static inline void print_hex_dump_debug(const char *prefix_str, int prefix_type, int rowsize, int groupsize, const void *buf, size_t len, bool ascii) { } #endif /** * print_hex_dump_bytes - shorthand form of print_hex_dump() with default params * @prefix_str: string to prefix each line with; * caller supplies trailing spaces for alignment if desired * @prefix_type: controls whether prefix of an offset, address, or none * is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE) * @buf: data blob to dump * @len: number of bytes in the @buf * * Calls print_hex_dump(), with log level of KERN_DEBUG, * rowsize of 16, groupsize of 1, and ASCII output included. */ #define print_hex_dump_bytes(prefix_str, prefix_type, buf, len) … #endif