[linux-block.git] / include / linux / dynamic_debug.h

#ifndef _DYNAMIC_DEBUG_H
#define _DYNAMIC_DEBUG_H

#include <linux/jump_label.h>

/* dynamic_printk_enabled, and dynamic_printk_enabled2 are bitmasks in which
 * bit n is set to 1 if any modname hashes into the bucket n, 0 otherwise. They
 * use independent hash functions, to reduce the chance of false positives.
 */
extern long long dynamic_debug_enabled;
extern long long dynamic_debug_enabled2;

/*
 * An instance of this structure is created in a special
 * ELF section at every dynamic debug callsite.  At runtime,
 * the special section is treated as an array of these.
 */
struct _ddebug {
	/*
	 * These fields are used to drive the user interface
	 * for selecting and displaying debug callsites.
	 */
	const char *modname;
	const char *function;
	const char *filename;
	const char *format;
	unsigned int lineno:24;
	/*
 	 * The flags field controls the behaviour at the callsite.
 	 * The bits here are changed dynamically when the user
	 * writes commands to <debugfs>/dynamic_debug/control
	 */
#define _DPRINTK_FLAGS_PRINT   (1<<0)  /* printk() a message using the format */
#define _DPRINTK_FLAGS_INCL_MODNAME	(1<<1)
#define _DPRINTK_FLAGS_INCL_FUNCNAME	(1<<2)
#define _DPRINTK_FLAGS_INCL_LINENO	(1<<3)
#define _DPRINTK_FLAGS_INCL_TID		(1<<4)
#define _DPRINTK_FLAGS_DEFAULT 0
	unsigned int flags:8;
	char enabled;
} __attribute__((aligned(8)));


int ddebug_add_module(struct _ddebug *tab, unsigned int n,
				const char *modname);

#if defined(CONFIG_DYNAMIC_DEBUG)
extern int ddebug_remove_module(const char *mod_name);
extern int __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
	__attribute__ ((format (printf, 2, 3)));

#define dynamic_pr_debug(fmt, ...) do {					\
	static struct _ddebug descriptor				\
	__used								\
	__attribute__((section("__verbose"), aligned(8))) =		\
	{ KBUILD_MODNAME, __func__, __FILE__, fmt, __LINE__,		\
		_DPRINTK_FLAGS_DEFAULT };				\
	if (unlikely(descriptor.enabled))				\
		__dynamic_pr_debug(&descriptor, pr_fmt(fmt), ##__VA_ARGS__); \
	} while (0)


#define dynamic_dev_dbg(dev, fmt, ...) do {				\
	static struct _ddebug descriptor				\
	__used								\
	__attribute__((section("__verbose"), aligned(8))) =		\
	{ KBUILD_MODNAME, __func__, __FILE__, fmt, __LINE__,		\
		_DPRINTK_FLAGS_DEFAULT };				\
	if (unlikely(descriptor.enabled))				\
		dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__);	\
	} while (0)

#else

static inline int ddebug_remove_module(const char *mod)
{
	return 0;
}

#define dynamic_pr_debug(fmt, ...)					\
	do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0)
#define dynamic_dev_dbg(dev, fmt, ...)					\
	do { if (0) dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); } while (0)
#endif

#endif
Commit	Line	Data
	1	#ifndef _DYNAMIC_DEBUG_H
	2	#define _DYNAMIC_DEBUG_H
	3
	4	#include <linux/jump_label.h>
	5
	6	/* dynamic_printk_enabled, and dynamic_printk_enabled2 are bitmasks in which
	7	* bit n is set to 1 if any modname hashes into the bucket n, 0 otherwise. They
	8	* use independent hash functions, to reduce the chance of false positives.
	9	*/
	10	extern long long dynamic_debug_enabled;
	11	extern long long dynamic_debug_enabled2;
	12
	13	/*
	14	* An instance of this structure is created in a special
	15	* ELF section at every dynamic debug callsite. At runtime,
	16	* the special section is treated as an array of these.
	17	*/
	18	struct _ddebug {
	19	/*
	20	* These fields are used to drive the user interface
	21	* for selecting and displaying debug callsites.
	22	*/
	23	const char *modname;
	24	const char *function;
	25	const char *filename;
	26	const char *format;
	27	unsigned int lineno:24;
	28	/*
	29	* The flags field controls the behaviour at the callsite.
	30	* The bits here are changed dynamically when the user
	31	* writes commands to <debugfs>/dynamic_debug/control
	32	*/
	33	#define _DPRINTK_FLAGS_PRINT (1<<0) /* printk() a message using the format */
	34	#define _DPRINTK_FLAGS_INCL_MODNAME (1<<1)
	35	#define _DPRINTK_FLAGS_INCL_FUNCNAME (1<<2)
	36	#define _DPRINTK_FLAGS_INCL_LINENO (1<<3)
	37	#define _DPRINTK_FLAGS_INCL_TID (1<<4)
	38	#define _DPRINTK_FLAGS_DEFAULT 0
	39	unsigned int flags:8;
	40	char enabled;
	41	} __attribute__((aligned(8)));
	42
	43
	44	int ddebug_add_module(struct _ddebug *tab, unsigned int n,
	45	const char *modname);
	46
	47	#if defined(CONFIG_DYNAMIC_DEBUG)
	48	extern int ddebug_remove_module(const char *mod_name);
	49	extern int __dynamic_pr_debug(struct _ddebug descriptor, const char fmt, ...)
	50	__attribute__ ((format (printf, 2, 3)));
	51
	52	#define dynamic_pr_debug(fmt, ...) do { \
	53	static struct _ddebug descriptor \
	54	__used \
	55	__attribute__((section("__verbose"), aligned(8))) = \
	56	{ KBUILD_MODNAME, __func__, __FILE__, fmt, __LINE__, \
	57	_DPRINTK_FLAGS_DEFAULT }; \
	58	if (unlikely(descriptor.enabled)) \
	59	__dynamic_pr_debug(&descriptor, pr_fmt(fmt), ##__VA_ARGS__); \
	60	} while (0)
	61
	62
	63	#define dynamic_dev_dbg(dev, fmt, ...) do { \
	64	static struct _ddebug descriptor \
	65	__used \
	66	__attribute__((section("__verbose"), aligned(8))) = \
	67	{ KBUILD_MODNAME, __func__, __FILE__, fmt, __LINE__, \
	68	_DPRINTK_FLAGS_DEFAULT }; \
	69	if (unlikely(descriptor.enabled)) \
	70	dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); \
	71	} while (0)
	72
	73	#else
	74
	75	static inline int ddebug_remove_module(const char *mod)
	76	{
	77	return 0;
	78	}
	79
	80	#define dynamic_pr_debug(fmt, ...) \
	81	do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0)
	82	#define dynamic_dev_dbg(dev, fmt, ...) \
	83	do { if (0) dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); } while (0)
	84	#endif
	85
	86	#endif