[lttng-modules.git] / lttng-events.h

#ifndef _LTTNG_EVENTS_H
#define _LTTNG_EVENTS_H

/*
 * lttng-events.h
 *
 * Holds LTTng per-session event registry.
 *
 * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; only
 * version 2.1 of the License.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <linux/version.h>
#include <linux/list.h>
#include <linux/kprobes.h>
#include <linux/kref.h>
#include "wrapper/uuid.h"
#include "lttng-abi.h"
#include "lttng-abi-old.h"

#define lttng_is_signed_type(type)	(((type)(-1)) < 0)

struct lttng_channel;
struct lttng_session;
struct lttng_metadata_cache;
struct lib_ring_buffer_ctx;
struct perf_event;
struct perf_event_attr;

/* Type description */

/* Update the astract_types name table in lttng-types.c along with this enum */
enum abstract_types {
	atype_integer,
	atype_enum,
	atype_array,
	atype_sequence,
	atype_string,
	NR_ABSTRACT_TYPES,
};

/* Update the string_encodings name table in lttng-types.c along with this enum */
enum lttng_string_encodings {
	lttng_encode_none = 0,
	lttng_encode_UTF8 = 1,
	lttng_encode_ASCII = 2,
	NR_STRING_ENCODINGS,
};

enum channel_type {
	PER_CPU_CHANNEL,
	METADATA_CHANNEL,
};

struct lttng_enum_entry {
	unsigned long long start, end;	/* start and end are inclusive */
	const char *string;
};

#define __type_integer(_type, _byte_order, _base, _encoding)	\
	{							\
	    .atype = atype_integer,				\
	    .u.basic.integer =					\
		{						\
		  .size = sizeof(_type) * CHAR_BIT,		\
		  .alignment = lttng_alignof(_type) * CHAR_BIT,	\
		  .signedness = lttng_is_signed_type(_type),	\
		  .reverse_byte_order = _byte_order != __BYTE_ORDER,	\
		  .base = _base,				\
		  .encoding = lttng_encode_##_encoding,		\
		},						\
	}							\

struct lttng_integer_type {
	unsigned int size;		/* in bits */
	unsigned short alignment;	/* in bits */
	unsigned int signedness:1,
		reverse_byte_order:1;
	unsigned int base;		/* 2, 8, 10, 16, for pretty print */
	enum lttng_string_encodings encoding;
};

union _lttng_basic_type {
	struct lttng_integer_type integer;
	struct {
		const char *name;
	} enumeration;
	struct {
		enum lttng_string_encodings encoding;
	} string;
};

struct lttng_basic_type {
	enum abstract_types atype;
	union {
		union _lttng_basic_type basic;
	} u;
};

struct lttng_type {
	enum abstract_types atype;
	union {
		union _lttng_basic_type basic;
		struct {
			struct lttng_basic_type elem_type;
			unsigned int length;		/* num. elems. */
		} array;
		struct {
			struct lttng_basic_type length_type;
			struct lttng_basic_type elem_type;
		} sequence;
	} u;
};

struct lttng_enum {
	const char *name;
	struct lttng_type container_type;
	const struct lttng_enum_entry *entries;
	unsigned int len;
};

/* Event field description */

struct lttng_event_field {
	const char *name;
	struct lttng_type type;
};

/*
 * We need to keep this perf counter field separately from struct
 * lttng_ctx_field because cpu hotplug needs fixed-location addresses.
 */
struct lttng_perf_counter_field {
	struct notifier_block nb;
	int hp_enable;
	struct perf_event_attr *attr;
	struct perf_event **e;	/* per-cpu array */
};

struct lttng_ctx_field {
	struct lttng_event_field event_field;
	size_t (*get_size)(size_t offset);
	void (*record)(struct lttng_ctx_field *field,
		       struct lib_ring_buffer_ctx *ctx,
		       struct lttng_channel *chan);
	union {
		struct lttng_perf_counter_field *perf_counter;
	} u;
	void (*destroy)(struct lttng_ctx_field *field);
};

struct lttng_ctx {
	struct lttng_ctx_field *fields;
	unsigned int nr_fields;
	unsigned int allocated_fields;
};

struct lttng_event_desc {
	const char *name;
	void *probe_callback;
	const struct lttng_event_ctx *ctx;	/* context */
	const struct lttng_event_field *fields;	/* event payload */
	unsigned int nr_fields;
	struct module *owner;
};

struct lttng_probe_desc {
	const struct lttng_event_desc **event_desc;
	unsigned int nr_events;
	struct list_head head;			/* chain registered probes */
};

struct lttng_krp;				/* Kretprobe handling */

/*
 * lttng_event structure is referred to by the tracing fast path. It must be
 * kept small.
 */
struct lttng_event {
	unsigned int id;
	struct lttng_channel *chan;
	int enabled;
	const struct lttng_event_desc *desc;
	void *filter;
	struct lttng_ctx *ctx;
	enum lttng_kernel_instrumentation instrumentation;
	union {
		struct {
			struct kprobe kp;
			char *symbol_name;
		} kprobe;
		struct {
			struct lttng_krp *lttng_krp;
			char *symbol_name;
		} kretprobe;
		struct {
			char *symbol_name;
		} ftrace;
	} u;
	struct list_head list;		/* Event list */
	unsigned int metadata_dumped:1;
};

struct lttng_channel_ops {
	struct channel *(*channel_create)(const char *name,
				struct lttng_channel *lttng_chan,
				void *buf_addr,
				size_t subbuf_size, size_t num_subbuf,
				unsigned int switch_timer_interval,
				unsigned int read_timer_interval);
	void (*channel_destroy)(struct channel *chan);
	struct lib_ring_buffer *(*buffer_read_open)(struct channel *chan);
	int (*buffer_has_read_closed_stream)(struct channel *chan);
	void (*buffer_read_close)(struct lib_ring_buffer *buf);
	int (*event_reserve)(struct lib_ring_buffer_ctx *ctx,
			     uint32_t event_id);
	void (*event_commit)(struct lib_ring_buffer_ctx *ctx);
	void (*event_write)(struct lib_ring_buffer_ctx *ctx, const void *src,
			    size_t len);
	void (*event_write_from_user)(struct lib_ring_buffer_ctx *ctx,
				      const void *src, size_t len);
	void (*event_memset)(struct lib_ring_buffer_ctx *ctx,
			     int c, size_t len);
	/*
	 * packet_avail_size returns the available size in the current
	 * packet. Note that the size returned is only a hint, since it
	 * may change due to concurrent writes.
	 */
	size_t (*packet_avail_size)(struct channel *chan);
	wait_queue_head_t *(*get_writer_buf_wait_queue)(struct channel *chan, int cpu);
	wait_queue_head_t *(*get_hp_wait_queue)(struct channel *chan);
	int (*is_finalized)(struct channel *chan);
	int (*is_disabled)(struct channel *chan);
};

struct lttng_transport {
	char *name;
	struct module *owner;
	struct list_head node;
	struct lttng_channel_ops ops;
};

struct lttng_channel {
	unsigned int id;
	struct channel *chan;		/* Channel buffers */
	int enabled;
	struct lttng_ctx *ctx;
	/* Event ID management */
	struct lttng_session *session;
	struct file *file;		/* File associated to channel */
	unsigned int free_event_id;	/* Next event ID to allocate */
	struct list_head list;		/* Channel list */
	struct lttng_channel_ops *ops;
	struct lttng_transport *transport;
	struct lttng_event **sc_table;	/* for syscall tracing */
	struct lttng_event **compat_sc_table;
	struct lttng_event *sc_unknown;	/* for unknown syscalls */
	struct lttng_event *sc_compat_unknown;
	struct lttng_event *sc_exit;	/* for syscall exit */
	int header_type;		/* 0: unset, 1: compact, 2: large */
	enum channel_type channel_type;
	unsigned int metadata_dumped:1;
};

struct lttng_metadata_stream {
	void *priv;			/* Ring buffer private data */
	struct lttng_metadata_cache *metadata_cache;
	unsigned int metadata_in;	/* Bytes read from the cache */
	unsigned int metadata_out;	/* Bytes consumed from stream */
	int finalized;			/* Has channel been finalized */
	wait_queue_head_t read_wait;	/* Reader buffer-level wait queue */
	struct list_head list;		/* Stream list */
	struct lttng_transport *transport;
};

struct lttng_session {
	int active;			/* Is trace session active ? */
	int been_active;		/* Has trace session been active ? */
	struct file *file;		/* File associated to session */
	struct list_head chan;		/* Channel list head */
	struct list_head events;	/* Event list head */
	struct list_head list;		/* Session list */
	unsigned int free_chan_id;	/* Next chan ID to allocate */
	uuid_le uuid;			/* Trace session unique ID */
	struct lttng_metadata_cache *metadata_cache;
	unsigned int metadata_dumped:1;
};

struct lttng_metadata_cache {
	char *data;			/* Metadata cache */
	unsigned int cache_alloc;	/* Metadata allocated size (bytes) */
	unsigned int metadata_written;	/* Number of bytes written in metadata cache */
	struct kref refcount;		/* Metadata cache usage */
	struct list_head metadata_stream;	/* Metadata stream list */
};

struct lttng_session *lttng_session_create(void);
int lttng_session_enable(struct lttng_session *session);
int lttng_session_disable(struct lttng_session *session);
void lttng_session_destroy(struct lttng_session *session);
void metadata_cache_destroy(struct kref *kref);

struct lttng_channel *lttng_channel_create(struct lttng_session *session,
				       const char *transport_name,
				       void *buf_addr,
				       size_t subbuf_size, size_t num_subbuf,
				       unsigned int switch_timer_interval,
				       unsigned int read_timer_interval,
				       enum channel_type channel_type);
struct lttng_channel *lttng_global_channel_create(struct lttng_session *session,
				       int overwrite, void *buf_addr,
				       size_t subbuf_size, size_t num_subbuf,
				       unsigned int switch_timer_interval,
				       unsigned int read_timer_interval);

void lttng_metadata_channel_destroy(struct lttng_channel *chan);
struct lttng_event *lttng_event_create(struct lttng_channel *chan,
				   struct lttng_kernel_event *event_param,
				   void *filter,
				   const struct lttng_event_desc *internal_desc);
struct lttng_event *lttng_event_compat_old_create(struct lttng_channel *chan,
		struct lttng_kernel_old_event *old_event_param,
		void *filter,
		const struct lttng_event_desc *internal_desc);

int lttng_channel_enable(struct lttng_channel *channel);
int lttng_channel_disable(struct lttng_channel *channel);
int lttng_event_enable(struct lttng_event *event);
int lttng_event_disable(struct lttng_event *event);

void lttng_transport_register(struct lttng_transport *transport);
void lttng_transport_unregister(struct lttng_transport *transport);

void synchronize_trace(void);
int lttng_abi_init(void);
int lttng_abi_compat_old_init(void);
void lttng_abi_exit(void);
void lttng_abi_compat_old_exit(void);

int lttng_probe_register(struct lttng_probe_desc *desc);
void lttng_probe_unregister(struct lttng_probe_desc *desc);
const struct lttng_event_desc *lttng_event_get(const char *name);
void lttng_event_put(const struct lttng_event_desc *desc);
int lttng_probes_init(void);
void lttng_probes_exit(void);

int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
		struct channel *chan);

#if defined(CONFIG_HAVE_SYSCALL_TRACEPOINTS)
int lttng_syscalls_register(struct lttng_channel *chan, void *filter);
int lttng_syscalls_unregister(struct lttng_channel *chan);
#else
static inline int lttng_syscalls_register(struct lttng_channel *chan, void *filter)
{
	return -ENOSYS;
}

static inline int lttng_syscalls_unregister(struct lttng_channel *chan)
{
	return 0;
}
#endif

struct lttng_ctx_field *lttng_append_context(struct lttng_ctx **ctx);
int lttng_find_context(struct lttng_ctx *ctx, const char *name);
void lttng_remove_context_field(struct lttng_ctx **ctx,
				struct lttng_ctx_field *field);
void lttng_destroy_context(struct lttng_ctx *ctx);
int lttng_add_pid_to_ctx(struct lttng_ctx **ctx);
int lttng_add_procname_to_ctx(struct lttng_ctx **ctx);
int lttng_add_prio_to_ctx(struct lttng_ctx **ctx);
int lttng_add_nice_to_ctx(struct lttng_ctx **ctx);
int lttng_add_vpid_to_ctx(struct lttng_ctx **ctx);
int lttng_add_tid_to_ctx(struct lttng_ctx **ctx);
int lttng_add_vtid_to_ctx(struct lttng_ctx **ctx);
int lttng_add_ppid_to_ctx(struct lttng_ctx **ctx);
int lttng_add_vppid_to_ctx(struct lttng_ctx **ctx);
int lttng_add_hostname_to_ctx(struct lttng_ctx **ctx);
#if defined(CONFIG_PERF_EVENTS) && (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,33))
int lttng_add_perf_counter_to_ctx(uint32_t type,
				  uint64_t config,
				  const char *name,
				  struct lttng_ctx **ctx);
#else
static inline
int lttng_add_perf_counter_to_ctx(uint32_t type,
				  uint64_t config,
				  const char *name,
				  struct lttng_ctx **ctx)
{
	return -ENOSYS;
}
#endif

extern int lttng_statedump_start(struct lttng_session *session);

#ifdef CONFIG_KPROBES
int lttng_kprobes_register(const char *name,
		const char *symbol_name,
		uint64_t offset,
		uint64_t addr,
		struct lttng_event *event);
void lttng_kprobes_unregister(struct lttng_event *event);
void lttng_kprobes_destroy_private(struct lttng_event *event);
#else
static inline
int lttng_kprobes_register(const char *name,
		const char *symbol_name,
		uint64_t offset,
		uint64_t addr,
		struct lttng_event *event)
{
	return -ENOSYS;
}

static inline
void lttng_kprobes_unregister(struct lttng_event *event)
{
}

static inline
void lttng_kprobes_destroy_private(struct lttng_event *event)
{
}
#endif

#ifdef CONFIG_KRETPROBES
int lttng_kretprobes_register(const char *name,
		const char *symbol_name,
		uint64_t offset,
		uint64_t addr,
		struct lttng_event *event_entry,
		struct lttng_event *event_exit);
void lttng_kretprobes_unregister(struct lttng_event *event);
void lttng_kretprobes_destroy_private(struct lttng_event *event);
#else
static inline
int lttng_kretprobes_register(const char *name,
		const char *symbol_name,
		uint64_t offset,
		uint64_t addr,
		struct lttng_event *event_entry,
		struct lttng_event *event_exit)
{
	return -ENOSYS;
}

static inline
void lttng_kretprobes_unregister(struct lttng_event *event)
{
}

static inline
void lttng_kretprobes_destroy_private(struct lttng_event *event)
{
}
#endif

#ifdef CONFIG_DYNAMIC_FTRACE
int lttng_ftrace_register(const char *name,
			  const char *symbol_name,
			  struct lttng_event *event);
void lttng_ftrace_unregister(struct lttng_event *event);
void lttng_ftrace_destroy_private(struct lttng_event *event);
#else
static inline
int lttng_ftrace_register(const char *name,
			  const char *symbol_name,
			  struct lttng_event *event)
{
	return -ENOSYS;
}

static inline
void lttng_ftrace_unregister(struct lttng_event *event)
{
}

static inline
void lttng_ftrace_destroy_private(struct lttng_event *event)
{
}
#endif

int lttng_calibrate(struct lttng_kernel_calibrate *calibrate);

extern const struct file_operations lttng_tracepoint_list_fops;

#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,35))
#define TRACEPOINT_HAS_DATA_ARG
#endif

#endif /* _LTTNG_EVENTS_H */
Commit	Line	Data
	1	#ifndef _LTTNG_EVENTS_H
	2	#define _LTTNG_EVENTS_H
	3
	4	/*
	5	* lttng-events.h
	6	*
	7	* Holds LTTng per-session event registry.
	8	*
	9	* Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	10	*
	11	* This library is free software; you can redistribute it and/or
	12	* modify it under the terms of the GNU Lesser General Public
	13	* License as published by the Free Software Foundation; only
	14	* version 2.1 of the License.
	15	*
	16	* This library is distributed in the hope that it will be useful,
	17	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	18	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	19	* Lesser General Public License for more details.
	20	*
	21	* You should have received a copy of the GNU Lesser General Public
	22	* License along with this library; if not, write to the Free Software
	23	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	24	*/
	25
	26	#include <linux/version.h>
	27	#include <linux/list.h>
	28	#include <linux/kprobes.h>
	29	#include <linux/kref.h>
	30	#include "wrapper/uuid.h"
	31	#include "lttng-abi.h"
	32	#include "lttng-abi-old.h"
	33
	34	#define lttng_is_signed_type(type) (((type)(-1)) < 0)
	35
	36	struct lttng_channel;
	37	struct lttng_session;
	38	struct lttng_metadata_cache;
	39	struct lib_ring_buffer_ctx;
	40	struct perf_event;
	41	struct perf_event_attr;
	42
	43	/* Type description */
	44
	45	/* Update the astract_types name table in lttng-types.c along with this enum */
	46	enum abstract_types {
	47	atype_integer,
	48	atype_enum,
	49	atype_array,
	50	atype_sequence,
	51	atype_string,
	52	NR_ABSTRACT_TYPES,
	53	};
	54
	55	/* Update the string_encodings name table in lttng-types.c along with this enum */
	56	enum lttng_string_encodings {
	57	lttng_encode_none = 0,
	58	lttng_encode_UTF8 = 1,
	59	lttng_encode_ASCII = 2,
	60	NR_STRING_ENCODINGS,
	61	};
	62
	63	enum channel_type {
	64	PER_CPU_CHANNEL,
	65	METADATA_CHANNEL,
	66	};
	67
	68	struct lttng_enum_entry {
	69	unsigned long long start, end; /* start and end are inclusive */
	70	const char *string;
	71	};
	72
	73	#define __type_integer(_type, _byte_order, _base, _encoding) \
	74	{ \
	75	.atype = atype_integer, \
	76	.u.basic.integer = \
	77	{ \
	78	.size = sizeof(_type) * CHAR_BIT, \
	79	.alignment = lttng_alignof(_type) * CHAR_BIT, \
	80	.signedness = lttng_is_signed_type(_type), \
	81	.reverse_byte_order = _byte_order != __BYTE_ORDER, \
	82	.base = _base, \
	83	.encoding = lttng_encode_##_encoding, \
	84	}, \
	85	} \
	86
	87	struct lttng_integer_type {
	88	unsigned int size; /* in bits */
	89	unsigned short alignment; /* in bits */
	90	unsigned int signedness:1,
	91	reverse_byte_order:1;
	92	unsigned int base; /* 2, 8, 10, 16, for pretty print */
	93	enum lttng_string_encodings encoding;
	94	};
	95
	96	union _lttng_basic_type {
	97	struct lttng_integer_type integer;
	98	struct {
	99	const char *name;
	100	} enumeration;
	101	struct {
	102	enum lttng_string_encodings encoding;
	103	} string;
	104	};
	105
	106	struct lttng_basic_type {
	107	enum abstract_types atype;
	108	union {
	109	union _lttng_basic_type basic;
	110	} u;
	111	};
	112
	113	struct lttng_type {
	114	enum abstract_types atype;
	115	union {
	116	union _lttng_basic_type basic;
	117	struct {
	118	struct lttng_basic_type elem_type;
	119	unsigned int length; /* num. elems. */
	120	} array;
	121	struct {
	122	struct lttng_basic_type length_type;
	123	struct lttng_basic_type elem_type;
	124	} sequence;
	125	} u;
	126	};
	127
	128	struct lttng_enum {
	129	const char *name;
	130	struct lttng_type container_type;
	131	const struct lttng_enum_entry *entries;
	132	unsigned int len;
	133	};
	134
	135	/* Event field description */
	136
	137	struct lttng_event_field {
	138	const char *name;
	139	struct lttng_type type;
	140	};
	141
	142	/*
	143	* We need to keep this perf counter field separately from struct
	144	* lttng_ctx_field because cpu hotplug needs fixed-location addresses.
	145	*/
	146	struct lttng_perf_counter_field {
	147	struct notifier_block nb;
	148	int hp_enable;
	149	struct perf_event_attr *attr;
	150	struct perf_event *e; / per-cpu array */
	151	};
	152
	153	struct lttng_ctx_field {
	154	struct lttng_event_field event_field;
	155	size_t (*get_size)(size_t offset);
	156	void (record)(struct lttng_ctx_field field,
	157	struct lib_ring_buffer_ctx *ctx,
	158	struct lttng_channel *chan);
	159	union {
	160	struct lttng_perf_counter_field *perf_counter;
	161	} u;
	162	void (destroy)(struct lttng_ctx_field field);
	163	};
	164
	165	struct lttng_ctx {
	166	struct lttng_ctx_field *fields;
	167	unsigned int nr_fields;
	168	unsigned int allocated_fields;
	169	};
	170
	171	struct lttng_event_desc {
	172	const char *name;
	173	void *probe_callback;
	174	const struct lttng_event_ctx ctx; / context */
	175	const struct lttng_event_field fields; / event payload */
	176	unsigned int nr_fields;
	177	struct module *owner;
	178	};
	179
	180	struct lttng_probe_desc {
	181	const struct lttng_event_desc **event_desc;
	182	unsigned int nr_events;
	183	struct list_head head; /* chain registered probes */
	184	};
	185
	186	struct lttng_krp; /* Kretprobe handling */
	187
	188	/*
	189	* lttng_event structure is referred to by the tracing fast path. It must be
	190	* kept small.
	191	*/
	192	struct lttng_event {
	193	unsigned int id;
	194	struct lttng_channel *chan;
	195	int enabled;
	196	const struct lttng_event_desc *desc;
	197	void *filter;
	198	struct lttng_ctx *ctx;
	199	enum lttng_kernel_instrumentation instrumentation;
	200	union {
	201	struct {
	202	struct kprobe kp;
	203	char *symbol_name;
	204	} kprobe;
	205	struct {
	206	struct lttng_krp *lttng_krp;
	207	char *symbol_name;
	208	} kretprobe;
	209	struct {
	210	char *symbol_name;
	211	} ftrace;
	212	} u;
	213	struct list_head list; /* Event list */
	214	unsigned int metadata_dumped:1;
	215	};
	216
	217	struct lttng_channel_ops {
	218	struct channel (channel_create)(const char *name,
	219	struct lttng_channel *lttng_chan,
	220	void *buf_addr,
	221	size_t subbuf_size, size_t num_subbuf,
	222	unsigned int switch_timer_interval,
	223	unsigned int read_timer_interval);
	224	void (channel_destroy)(struct channel chan);
	225	struct lib_ring_buffer (buffer_read_open)(struct channel *chan);
	226	int (buffer_has_read_closed_stream)(struct channel chan);
	227	void (buffer_read_close)(struct lib_ring_buffer buf);
	228	int (event_reserve)(struct lib_ring_buffer_ctx ctx,
	229	uint32_t event_id);
	230	void (event_commit)(struct lib_ring_buffer_ctx ctx);
	231	void (event_write)(struct lib_ring_buffer_ctx ctx, const void *src,
	232	size_t len);
	233	void (event_write_from_user)(struct lib_ring_buffer_ctx ctx,
	234	const void *src, size_t len);
	235	void (event_memset)(struct lib_ring_buffer_ctx ctx,
	236	int c, size_t len);
	237	/*
	238	* packet_avail_size returns the available size in the current
	239	* packet. Note that the size returned is only a hint, since it
	240	* may change due to concurrent writes.
	241	*/
	242	size_t (packet_avail_size)(struct channel chan);
	243	wait_queue_head_t (get_writer_buf_wait_queue)(struct channel *chan, int cpu);
	244	wait_queue_head_t (get_hp_wait_queue)(struct channel *chan);
	245	int (is_finalized)(struct channel chan);
	246	int (is_disabled)(struct channel chan);
	247	};
	248
	249	struct lttng_transport {
	250	char *name;
	251	struct module *owner;
	252	struct list_head node;
	253	struct lttng_channel_ops ops;
	254	};
	255
	256	struct lttng_channel {
	257	unsigned int id;
	258	struct channel chan; / Channel buffers */
	259	int enabled;
	260	struct lttng_ctx *ctx;
	261	/* Event ID management */
	262	struct lttng_session *session;
	263	struct file file; / File associated to channel */
	264	unsigned int free_event_id; /* Next event ID to allocate */
	265	struct list_head list; /* Channel list */
	266	struct lttng_channel_ops *ops;
	267	struct lttng_transport *transport;
	268	struct lttng_event *sc_table; / for syscall tracing */
	269	struct lttng_event **compat_sc_table;
	270	struct lttng_event sc_unknown; / for unknown syscalls */
	271	struct lttng_event *sc_compat_unknown;
	272	struct lttng_event sc_exit; / for syscall exit */
	273	int header_type; /* 0: unset, 1: compact, 2: large */
	274	enum channel_type channel_type;
	275	unsigned int metadata_dumped:1;
	276	};
	277
	278	struct lttng_metadata_stream {
	279	void priv; / Ring buffer private data */
	280	struct lttng_metadata_cache *metadata_cache;
	281	unsigned int metadata_in; /* Bytes read from the cache */
	282	unsigned int metadata_out; /* Bytes consumed from stream */
	283	int finalized; /* Has channel been finalized */
	284	wait_queue_head_t read_wait; /* Reader buffer-level wait queue */
	285	struct list_head list; /* Stream list */
	286	struct lttng_transport *transport;
	287	};
	288
	289	struct lttng_session {
	290	int active; /* Is trace session active ? */
	291	int been_active; /* Has trace session been active ? */
	292	struct file file; / File associated to session */
	293	struct list_head chan; /* Channel list head */
	294	struct list_head events; /* Event list head */
	295	struct list_head list; /* Session list */
	296	unsigned int free_chan_id; /* Next chan ID to allocate */
	297	uuid_le uuid; /* Trace session unique ID */
	298	struct lttng_metadata_cache *metadata_cache;
	299	unsigned int metadata_dumped:1;
	300	};
	301
	302	struct lttng_metadata_cache {
	303	char data; / Metadata cache */
	304	unsigned int cache_alloc; /* Metadata allocated size (bytes) */
	305	unsigned int metadata_written; /* Number of bytes written in metadata cache */
	306	struct kref refcount; /* Metadata cache usage */
	307	struct list_head metadata_stream; /* Metadata stream list */
	308	};
	309
	310	struct lttng_session *lttng_session_create(void);
	311	int lttng_session_enable(struct lttng_session *session);
	312	int lttng_session_disable(struct lttng_session *session);
	313	void lttng_session_destroy(struct lttng_session *session);
	314	void metadata_cache_destroy(struct kref *kref);
	315
	316	struct lttng_channel lttng_channel_create(struct lttng_session session,
	317	const char *transport_name,
	318	void *buf_addr,
	319	size_t subbuf_size, size_t num_subbuf,
	320	unsigned int switch_timer_interval,
	321	unsigned int read_timer_interval,
	322	enum channel_type channel_type);
	323	struct lttng_channel lttng_global_channel_create(struct lttng_session session,
	324	int overwrite, void *buf_addr,
	325	size_t subbuf_size, size_t num_subbuf,
	326	unsigned int switch_timer_interval,
	327	unsigned int read_timer_interval);
	328
	329	void lttng_metadata_channel_destroy(struct lttng_channel *chan);
	330	struct lttng_event lttng_event_create(struct lttng_channel chan,
	331	struct lttng_kernel_event *event_param,
	332	void *filter,
	333	const struct lttng_event_desc *internal_desc);
	334	struct lttng_event lttng_event_compat_old_create(struct lttng_channel chan,
	335	struct lttng_kernel_old_event *old_event_param,
	336	void *filter,
	337	const struct lttng_event_desc *internal_desc);
	338
	339	int lttng_channel_enable(struct lttng_channel *channel);
	340	int lttng_channel_disable(struct lttng_channel *channel);
	341	int lttng_event_enable(struct lttng_event *event);
	342	int lttng_event_disable(struct lttng_event *event);
	343
	344	void lttng_transport_register(struct lttng_transport *transport);
	345	void lttng_transport_unregister(struct lttng_transport *transport);
	346
	347	void synchronize_trace(void);
	348	int lttng_abi_init(void);
	349	int lttng_abi_compat_old_init(void);
	350	void lttng_abi_exit(void);
	351	void lttng_abi_compat_old_exit(void);
	352
	353	int lttng_probe_register(struct lttng_probe_desc *desc);
	354	void lttng_probe_unregister(struct lttng_probe_desc *desc);
	355	const struct lttng_event_desc lttng_event_get(const char name);
	356	void lttng_event_put(const struct lttng_event_desc *desc);
	357	int lttng_probes_init(void);
	358	void lttng_probes_exit(void);
	359
	360	int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
	361	struct channel *chan);
	362
	363	#if defined(CONFIG_HAVE_SYSCALL_TRACEPOINTS)
	364	int lttng_syscalls_register(struct lttng_channel chan, void filter);
	365	int lttng_syscalls_unregister(struct lttng_channel *chan);
	366	#else
	367	static inline int lttng_syscalls_register(struct lttng_channel chan, void filter)
	368	{
	369	return -ENOSYS;
	370	}
	371
	372	static inline int lttng_syscalls_unregister(struct lttng_channel *chan)
	373	{
	374	return 0;
	375	}
	376	#endif
	377
	378	struct lttng_ctx_field lttng_append_context(struct lttng_ctx *ctx);
	379	int lttng_find_context(struct lttng_ctx ctx, const char name);
	380	void lttng_remove_context_field(struct lttng_ctx **ctx,
	381	struct lttng_ctx_field *field);
	382	void lttng_destroy_context(struct lttng_ctx *ctx);
	383	int lttng_add_pid_to_ctx(struct lttng_ctx **ctx);
	384	int lttng_add_procname_to_ctx(struct lttng_ctx **ctx);
	385	int lttng_add_prio_to_ctx(struct lttng_ctx **ctx);
	386	int lttng_add_nice_to_ctx(struct lttng_ctx **ctx);
	387	int lttng_add_vpid_to_ctx(struct lttng_ctx **ctx);
	388	int lttng_add_tid_to_ctx(struct lttng_ctx **ctx);
	389	int lttng_add_vtid_to_ctx(struct lttng_ctx **ctx);
	390	int lttng_add_ppid_to_ctx(struct lttng_ctx **ctx);
	391	int lttng_add_vppid_to_ctx(struct lttng_ctx **ctx);
	392	int lttng_add_hostname_to_ctx(struct lttng_ctx **ctx);
	393	#if defined(CONFIG_PERF_EVENTS) && (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,33))
	394	int lttng_add_perf_counter_to_ctx(uint32_t type,
	395	uint64_t config,
	396	const char *name,
	397	struct lttng_ctx **ctx);
	398	#else
	399	static inline
	400	int lttng_add_perf_counter_to_ctx(uint32_t type,
	401	uint64_t config,
	402	const char *name,
	403	struct lttng_ctx **ctx)
	404	{
	405	return -ENOSYS;
	406	}
	407	#endif
	408
	409	extern int lttng_statedump_start(struct lttng_session *session);
	410
	411	#ifdef CONFIG_KPROBES
	412	int lttng_kprobes_register(const char *name,
	413	const char *symbol_name,
	414	uint64_t offset,
	415	uint64_t addr,
	416	struct lttng_event *event);
	417	void lttng_kprobes_unregister(struct lttng_event *event);
	418	void lttng_kprobes_destroy_private(struct lttng_event *event);
	419	#else
	420	static inline
	421	int lttng_kprobes_register(const char *name,
	422	const char *symbol_name,
	423	uint64_t offset,
	424	uint64_t addr,
	425	struct lttng_event *event)
	426	{
	427	return -ENOSYS;
	428	}
	429
	430	static inline
	431	void lttng_kprobes_unregister(struct lttng_event *event)
	432	{
	433	}
	434
	435	static inline
	436	void lttng_kprobes_destroy_private(struct lttng_event *event)
	437	{
	438	}
	439	#endif
	440
	441	#ifdef CONFIG_KRETPROBES
	442	int lttng_kretprobes_register(const char *name,
	443	const char *symbol_name,
	444	uint64_t offset,
	445	uint64_t addr,
	446	struct lttng_event *event_entry,
	447	struct lttng_event *event_exit);
	448	void lttng_kretprobes_unregister(struct lttng_event *event);
	449	void lttng_kretprobes_destroy_private(struct lttng_event *event);
	450	#else
	451	static inline
	452	int lttng_kretprobes_register(const char *name,
	453	const char *symbol_name,
	454	uint64_t offset,
	455	uint64_t addr,
	456	struct lttng_event *event_entry,
	457	struct lttng_event *event_exit)
	458	{
	459	return -ENOSYS;
	460	}
	461
	462	static inline
	463	void lttng_kretprobes_unregister(struct lttng_event *event)
	464	{
	465	}
	466
	467	static inline
	468	void lttng_kretprobes_destroy_private(struct lttng_event *event)
	469	{
	470	}
	471	#endif
	472
	473	#ifdef CONFIG_DYNAMIC_FTRACE
	474	int lttng_ftrace_register(const char *name,
	475	const char *symbol_name,
	476	struct lttng_event *event);
	477	void lttng_ftrace_unregister(struct lttng_event *event);
	478	void lttng_ftrace_destroy_private(struct lttng_event *event);
	479	#else
	480	static inline
	481	int lttng_ftrace_register(const char *name,
	482	const char *symbol_name,
	483	struct lttng_event *event)
	484	{
	485	return -ENOSYS;
	486	}
	487
	488	static inline
	489	void lttng_ftrace_unregister(struct lttng_event *event)
	490	{
	491	}
	492
	493	static inline
	494	void lttng_ftrace_destroy_private(struct lttng_event *event)
	495	{
	496	}
	497	#endif
	498
	499	int lttng_calibrate(struct lttng_kernel_calibrate *calibrate);
	500
	501	extern const struct file_operations lttng_tracepoint_list_fops;
	502
	503	#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,35))
	504	#define TRACEPOINT_HAS_DATA_ARG
	505	#endif
	506
	507	#endif /* _LTTNG_EVENTS_H */