[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 "wrapper/uuid.h"
#include "lttng-abi.h"
#include "lttng-abi-old.h"

#undef is_signed_type
#define is_signed_type(type)		(((type)(-1)) < 0)

struct lttng_channel;
struct lttng_session;
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,
};

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 = 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 */
	unsigned int metadata_dumped:1;
};

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 lttng_channel *metadata;	/* Metadata channel */
	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 */
	unsigned int metadata_dumped:1;
};

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);

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);
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);

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);

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