kernel / include / linux / printk.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __KERNEL_PRINTK__
#define __KERNEL_PRINTK__

#include <stdarg.h>
#include <linux/init.h>
#include <linux/kern_levels.h>
#include <linux/linkage.h>
#include <linux/cache.h>
#include <linux/ratelimit_types.h>
#include <linux/once_lite.h>

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 2

static inline int printk_get_level(const char *buffer)
{
	if (buffer[0] == KERN_SOH_ASCII && buffer[1]) {
		switch (buffer[1]) {
		case '0' ... '7':
		case 'c':	/* KERN_CONT */
			return buffer[1];
		}
	}
	return 0;
}

static inline const char *printk_skip_level(const char *buffer)
{
	if (printk_get_level(buffer))
		return buffer + 2;

	return buffer;
}

static inline const char *printk_skip_headers(const char *buffer)
{
	while (printk_get_level(buffer))
		buffer = printk_skip_level(buffer);

	return buffer;
}

#define CONSOLE_EXT_LOG_MAX	8192

/* printk's without a loglevel use this.. */
#define MESSAGE_LOGLEVEL_DEFAULT CONFIG_MESSAGE_LOGLEVEL_DEFAULT

/* We show everything that is MORE important than this.. */
#define CONSOLE_LOGLEVEL_SILENT  0 /* Mum's the word */
#define CONSOLE_LOGLEVEL_MIN	 1 /* Minimum loglevel we let people use */
#define CONSOLE_LOGLEVEL_DEBUG	10 /* issue debug messages */
#define CONSOLE_LOGLEVEL_MOTORMOUTH 15	/* You can't shut this one up */

/*
 * 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 CONFIG_CONSOLE_LOGLEVEL_DEFAULT
#define CONSOLE_LOGLEVEL_QUIET	 CONFIG_CONSOLE_LOGLEVEL_QUIET

extern int console_printk[];

#define console_loglevel (console_printk[0])
#define default_message_loglevel (console_printk[1])
#define minimum_console_loglevel (console_printk[2])
#define default_console_loglevel (console_printk[3])

static inline void console_silent(void)
{
	console_loglevel = CONSOLE_LOGLEVEL_SILENT;
}

static inline void console_verbose(void)
{
	if (console_loglevel)
		console_loglevel = CONSOLE_LOGLEVEL_MOTORMOUTH;
}

/* strlen("ratelimit") + 1 */
#define DEVKMSG_STR_MAX_SIZE 10
extern char devkmsg_log_str[];
struct ctl_table;

extern int suppress_printk;

struct va_format {
	const char *fmt;
	va_list *va;
};

/*
 * 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		"[Firmware Bug]: "
#define FW_WARN		"[Firmware Warn]: "
#define FW_INFO		"[Firmware 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		"[Hardware Error]: "

/*
 * 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	"[Deprecated]: "

/*
 * Dummy printk for disabled debugging statements to use whilst maintaining
 * gcc's format checking.
 */
#define no_printk(fmt, ...)				\
({							\
	if (0)						\
		printk(fmt, ##__VA_ARGS__);		\
	0;						\
})

#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

#ifdef CONFIG_PRINTK_NMI
extern void printk_nmi_enter(void);
extern void printk_nmi_exit(void);
extern void printk_nmi_direct_enter(void);
extern void printk_nmi_direct_exit(void);
#else
static inline void printk_nmi_enter(void) { }
static inline void printk_nmi_exit(void) { }
static inline void printk_nmi_direct_enter(void) { }
static inline void printk_nmi_direct_exit(void) { }
#endif /* PRINTK_NMI */

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, ...);

/*
 * 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() __printk_ratelimit(__func__)
extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
				   unsigned int interval_msec);

extern int printk_delay_msec;
extern int dmesg_restrict;

extern int
devkmsg_sysctl_set_loglvl(struct ctl_table *table, int write, void *buf,
			  size_t *lenp, loff_t *ppos);

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;
extern void printk_safe_flush(void);
extern void printk_safe_flush_on_panic(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 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_safe_flush(void)
{
}

static inline void printk_safe_flush_on_panic(void)
{
}
#endif

#ifdef CONFIG_SMP
extern int __printk_cpu_trylock(void);
extern void __printk_wait_on_cpu_lock(void);
extern void __printk_cpu_unlock(void);

/**
 * printk_cpu_lock_irqsave() - Acquire the printk cpu-reentrant spinning
 *                             lock and disable interrupts.
 * @flags: Stack-allocated storage for saving local interrupt state,
 *         to be passed to printk_cpu_unlock_irqrestore().
 *
 * If the lock is owned by another CPU, spin until it becomes available.
 * Interrupts are restored while spinning.
 */
#define printk_cpu_lock_irqsave(flags)		\
	for (;;) {				\
		local_irq_save(flags);		\
		if (__printk_cpu_trylock())	\
			break;			\
		local_irq_restore(flags);	\
		__printk_wait_on_cpu_lock();	\
	}

/**
 * printk_cpu_unlock_irqrestore() - Release the printk cpu-reentrant spinning
 *                                  lock and restore interrupts.
 * @flags: Caller's saved interrupt state, from printk_cpu_lock_irqsave().
 */
#define printk_cpu_unlock_irqrestore(flags)	\
	do {					\
		__printk_cpu_unlock();		\
		local_irq_restore(flags);	\
	} while (0)				\

#else

#define printk_cpu_lock_irqsave(flags) ((void)flags)
#define printk_cpu_unlock_irqrestore(flags) ((void)flags)

#endif /* CONFIG_SMP */

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) fmt
#endif

/**
 * 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, ...) \
	printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
/**
 * 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, ...) \
	printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
/**
 * 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, ...) \
	printk(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
/**
 * 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, ...) \
	printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
/**
 * 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, ...) \
	printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
/**
 * 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, ...) \
	printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
/**
 * 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, ...) \
	printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)

/**
 * 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, ...) \
	printk(KERN_CONT fmt, ##__VA_ARGS__)

/**
 * 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(fmt, ...) \
	printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
#else
#define pr_devel(fmt, ...) \
	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
#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, ...)			\
	dynamic_pr_debug(fmt, ##__VA_ARGS__)
#elif defined(DEBUG)
#define pr_debug(fmt, ...) \
	printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
#else
#define pr_debug(fmt, ...) \
	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
#endif

/*
 * Print a one-time message (analogous to WARN_ONCE() et al):
 */

#ifdef CONFIG_PRINTK
#define printk_once(fmt, ...)					\
	DO_ONCE_LITE(printk, fmt, ##__VA_ARGS__)
#define printk_deferred_once(fmt, ...)				\
	DO_ONCE_LITE(printk_deferred, fmt, ##__VA_ARGS__)
#else
#define printk_once(fmt, ...)					\
	no_printk(fmt, ##__VA_ARGS__)
#define printk_deferred_once(fmt, ...)				\
	no_printk(fmt, ##__VA_ARGS__)
#endif

#define pr_emerg_once(fmt, ...)					\
	printk_once(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
#define pr_alert_once(fmt, ...)					\
	printk_once(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
#define pr_crit_once(fmt, ...)					\
	printk_once(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
#define pr_err_once(fmt, ...)					\
	printk_once(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
#define pr_warn_once(fmt, ...)					\
	printk_once(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
#define pr_notice_once(fmt, ...)				\
	printk_once(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
#define pr_info_once(fmt, ...)					\
	printk_once(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
/* no pr_cont_once, don't do that... */

#if defined(DEBUG)
#define pr_devel_once(fmt, ...)					\
	printk_once(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
#else
#define pr_devel_once(fmt, ...)					\
	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
#endif

/* If you are writing a driver, please use dev_dbg instead */
#if defined(DEBUG)
#define pr_debug_once(fmt, ...)					\
	printk_once(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
#else
#define pr_debug_once(fmt, ...)					\
	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
#endif

/*
 * ratelimited messages with local ratelimit_state,
 * no local ratelimit_state used in the !PRINTK case
 */
#ifdef CONFIG_PRINTK
#define printk_ratelimited(fmt, ...)					\
({									\
	static DEFINE_RATELIMIT_STATE(_rs,				\
				      DEFAULT_RATELIMIT_INTERVAL,	\
				      DEFAULT_RATELIMIT_BURST);		\
									\
	if (__ratelimit(&_rs))						\
		printk(fmt, ##__VA_ARGS__);				\
})
#else
#define printk_ratelimited(fmt, ...)					\
	no_printk(fmt, ##__VA_ARGS__)
#endif

#define pr_emerg_ratelimited(fmt, ...)					\
	printk_ratelimited(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
#define pr_alert_ratelimited(fmt, ...)					\
	printk_ratelimited(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
#define pr_crit_ratelimited(fmt, ...)					\
	printk_ratelimited(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
#define pr_err_ratelimited(fmt, ...)					\
	printk_ratelimited(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
#define pr_warn_ratelimited(fmt, ...)					\
	printk_ratelimited(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
#define pr_notice_ratelimited(fmt, ...)					\
	printk_ratelimited(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
#define pr_info_ratelimited(fmt, ...)					\
	printk_ratelimited(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
/* no pr_cont_ratelimited, don't do that... */

#if defined(DEBUG)
#define pr_devel_ratelimited(fmt, ...)					\
	printk_ratelimited(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
#else
#define pr_devel_ratelimited(fmt, ...)					\
	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
#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, ...)					\
do {									\
	static DEFINE_RATELIMIT_STATE(_rs,				\
				      DEFAULT_RATELIMIT_INTERVAL,	\
				      DEFAULT_RATELIMIT_BURST);		\
	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, pr_fmt(fmt));		\
	if (DYNAMIC_DEBUG_BRANCH(descriptor) &&				\
	    __ratelimit(&_rs))						\
		__dynamic_pr_debug(&descriptor, pr_fmt(fmt), ##__VA_ARGS__);	\
} while (0)
#elif defined(DEBUG)
#define pr_debug_ratelimited(fmt, ...)					\
	printk_ratelimited(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
#else
#define pr_debug_ratelimited(fmt, ...) \
	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
#endif

extern const struct file_operations kmsg_fops;

enum {
	DUMP_PREFIX_NONE,
	DUMP_PREFIX_ADDRESS,
	DUMP_PREFIX_OFFSET
};
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)	\
	dynamic_hex_dump(prefix_str, prefix_type, rowsize,	\
			 groupsize, buf, len, ascii)
#elif defined(DEBUG)
#define print_hex_dump_debug(prefix_str, prefix_type, rowsize,		\
			     groupsize, buf, len, ascii)		\
	print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, rowsize,	\
		       groupsize, buf, len, ascii)
#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)	\
	print_hex_dump_debug(prefix_str, prefix_type, 16, 1, buf, len, true)

#endif