lttng: tracer control and core structures

#ifndef _LTT_ENDIAN_H

#define _LTT_ENDIAN_H

/*

 * ltt-endian.h

 *

 * Copyright 2010 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

 *

 * Dual LGPL v2.1/GPL v2 license.

 */

#ifdef __KERNEL__

# include <asm/byteorder.h>

# ifdef __BIG_ENDIAN

#  define __BYTE_ORDER __BIG_ENDIAN

# elif defined(__LITTLE_ENDIAN)

#  define __BYTE_ORDER __LITTLE_ENDIAN

# else

#  error "unknown endianness"

# endif

#ifndef __BIG_ENDIAN

# define __BIG_ENDIAN 4321

#endif

#ifndef __LITTLE_ENDIAN

# define __LITTLE_ENDIAN 1234

#endif

#else

# include <endian.h>

#endif

#endif /* _LTT_ENDIAN_H */

#ifndef _LTT_EVENTS_H

#define _LTT_EVENTS_H

/*

 * ltt-events.h

 *

 * Copyright 2010 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

 *

 * Holds LTTng per-session event registry.

 *

 * Dual LGPL v2.1/GPL v2 license.

 */

#include <linux/list.h>

#include <linux/kprobes.h>

#include "wrapper/uuid.h"

#include "ltt-debugfs-abi.h"

#undef is_signed_type

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

struct ltt_channel;

struct ltt_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 = ltt_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;

	unsigned int 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 ltt_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 */

/*

 * ltt_event structure is referred to by the tracing fast path. It must be

 * kept small.

 */

struct ltt_event {

	unsigned int id;

	struct ltt_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 */

	int metadata_dumped:1;

};

struct ltt_channel_ops {

	struct channel *(*channel_create)(const char *name,

				struct ltt_channel *ltt_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 ltt_transport {

	char *name;

	struct module *owner;

	struct list_head node;

	struct ltt_channel_ops ops;

};

struct ltt_channel {

	unsigned int id;

	struct channel *chan;		/* Channel buffers */

	int enabled;

	struct lttng_ctx *ctx;

	/* Event ID management */

	struct ltt_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 ltt_channel_ops *ops;

	struct ltt_transport *transport;

	struct ltt_event **sc_table;	/* for syscall tracing */

	struct ltt_event **compat_sc_table;

	struct ltt_event *sc_unknown;	/* for unknown syscalls */

	struct ltt_event *sc_compat_unknown;

	struct ltt_event *sc_exit;	/* for syscall exit */

	int header_type;		/* 0: unset, 1: compact, 2: large */

	int metadata_dumped:1;

};

struct ltt_session {

	int active;			/* Is trace session active ? */

	int been_active;		/* Has trace session been active ? */

	struct file *file;		/* File associated to session */

	struct ltt_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 */

	int metadata_dumped:1;

};

struct ltt_session *ltt_session_create(void);

int ltt_session_enable(struct ltt_session *session);

int ltt_session_disable(struct ltt_session *session);

void ltt_session_destroy(struct ltt_session *session);

struct ltt_channel *ltt_channel_create(struct ltt_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 ltt_channel *ltt_global_channel_create(struct ltt_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 ltt_event *ltt_event_create(struct ltt_channel *chan,

				   struct lttng_kernel_event *event_param,

				   void *filter,

				   const struct lttng_event_desc *internal_desc);

int ltt_channel_enable(struct ltt_channel *channel);

int ltt_channel_disable(struct ltt_channel *channel);

int ltt_event_enable(struct ltt_event *event);

int ltt_event_disable(struct ltt_event *event);

void ltt_transport_register(struct ltt_transport *transport);

void ltt_transport_unregister(struct ltt_transport *transport);

void synchronize_trace(void);

int ltt_debugfs_abi_init(void);

void ltt_debugfs_abi_exit(void);

int ltt_probe_register(struct lttng_probe_desc *desc);

void ltt_probe_unregister(struct lttng_probe_desc *desc);

const struct lttng_event_desc *ltt_event_get(const char *name);

void ltt_event_put(const struct lttng_event_desc *desc);

int ltt_probes_init(void);

void ltt_probes_exit(void);

#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS

int lttng_syscalls_register(struct ltt_channel *chan, void *filter);

int lttng_syscalls_unregister(struct ltt_channel *chan);

#else

static inline int lttng_syscalls_register(struct ltt_channel *chan, void *filter)

{

	return -ENOSYS;

}

static inline int lttng_syscalls_unregister(struct ltt_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);

#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

#ifdef CONFIG_KPROBES

int lttng_kprobes_register(const char *name,

		const char *symbol_name,

		uint64_t offset,

		uint64_t addr,

		struct ltt_event *event);

void lttng_kprobes_unregister(struct ltt_event *event);

void lttng_kprobes_destroy_private(struct ltt_event *event);

#else

static inline

int lttng_kprobes_register(const char *name,

		const char *symbol_name,

		uint64_t offset,

		uint64_t addr,

		struct ltt_event *event)

{

	return -ENOSYS;

}

static inline

void lttng_kprobes_unregister(struct ltt_event *event)

{

}

static inline

void lttng_kprobes_destroy_private(struct ltt_event *event)

{

}

#endif

#ifdef CONFIG_KRETPROBES

int lttng_kretprobes_register(const char *name,

		const char *symbol_name,

		uint64_t offset,

		uint64_t addr,

		struct ltt_event *event_entry,

		struct ltt_event *event_exit);

void lttng_kretprobes_unregister(struct ltt_event *event);

void lttng_kretprobes_destroy_private(struct ltt_event *event);

#else

static inline

int lttng_kretprobes_register(const char *name,

		const char *symbol_name,

		uint64_t offset,

		uint64_t addr,

		struct ltt_event *event_entry,

		struct ltt_event *event_exit)

{

	return -ENOSYS;

}

static inline

void lttng_kretprobes_unregister(struct ltt_event *event)

{

}

static inline

void lttng_kretprobes_destroy_private(struct ltt_event *event)

{

}

#endif

#ifdef CONFIG_DYNAMIC_FTRACE

int lttng_ftrace_register(const char *name,

			  const char *symbol_name,

			  struct ltt_event *event);

void lttng_ftrace_unregister(struct ltt_event *event);

void lttng_ftrace_destroy_private(struct ltt_event *event);

#else

static inline

int lttng_ftrace_register(const char *name,

			  const char *symbol_name,

			  struct ltt_event *event)

{

	return -ENOSYS;

}

static inline

void lttng_ftrace_unregister(struct ltt_event *event)

{

}

static inline

void lttng_ftrace_destroy_private(struct ltt_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 /* _LTT_EVENTS_H */

/*

 * ltt-probes.c

 *

 * Copyright 2010 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

 *

 * Holds LTTng probes registry.

 *

 * Dual LGPL v2.1/GPL v2 license.

 */

#include <linux/module.h>

#include <linux/list.h>

#include <linux/mutex.h>

#include <linux/seq_file.h>

#include "ltt-events.h"

static LIST_HEAD(probe_list);

static DEFINE_MUTEX(probe_mutex);

static

const struct lttng_event_desc *find_event(const char *name)

{

	struct lttng_probe_desc *probe_desc;

	int i;

	list_for_each_entry(probe_desc, &probe_list, head) {

		for (i = 0; i < probe_desc->nr_events; i++) {

			if (!strcmp(probe_desc->event_desc[i]->name, name))

				return probe_desc->event_desc[i];

		}

	}

	return NULL;

}

int ltt_probe_register(struct lttng_probe_desc *desc)

{

	int ret = 0;

	int i;

	mutex_lock(&probe_mutex);

	/*

	 * TODO: This is O(N^2). Turn into a hash table when probe registration

	 * overhead becomes an issue.

	 */

	for (i = 0; i < desc->nr_events; i++) {

		if (find_event(desc->event_desc[i]->name)) {

			ret = -EEXIST;

			goto end;

		}

	}

	list_add(&desc->head, &probe_list);

end:

	mutex_unlock(&probe_mutex);

	return ret;

}

EXPORT_SYMBOL_GPL(ltt_probe_register);

void ltt_probe_unregister(struct lttng_probe_desc *desc)

{

	mutex_lock(&probe_mutex);

	list_del(&desc->head);

	mutex_unlock(&probe_mutex);

}

EXPORT_SYMBOL_GPL(ltt_probe_unregister);

const struct lttng_event_desc *ltt_event_get(const char *name)

{

	const struct lttng_event_desc *event;

	int ret;

	mutex_lock(&probe_mutex);

	event = find_event(name);

	mutex_unlock(&probe_mutex);

	if (!event)

		return NULL;

	ret = try_module_get(event->owner);

	WARN_ON_ONCE(!ret);

	return event;

}

EXPORT_SYMBOL_GPL(ltt_event_get);

void ltt_event_put(const struct lttng_event_desc *event)

{

	module_put(event->owner);

}

EXPORT_SYMBOL_GPL(ltt_event_put);

static

void *tp_list_start(struct seq_file *m, loff_t *pos)

{

	struct lttng_probe_desc *probe_desc;

	int iter = 0, i;

	mutex_lock(&probe_mutex);

	list_for_each_entry(probe_desc, &probe_list, head) {

		for (i = 0; i < probe_desc->nr_events; i++) {

			if (iter++ >= *pos)

				return (void *) probe_desc->event_desc[i];

		}

	}

	/* End of list */

	return NULL;

}

static

void *tp_list_next(struct seq_file *m, void *p, loff_t *ppos)

{

	struct lttng_probe_desc *probe_desc;

	int iter = 0, i;

	(*ppos)++;

	list_for_each_entry(probe_desc, &probe_list, head) {

		for (i = 0; i < probe_desc->nr_events; i++) {

			if (iter++ >= *ppos)

				return (void *) probe_desc->event_desc[i];

		}

	}

	/* End of list */

	return NULL;

}

static

void tp_list_stop(struct seq_file *m, void *p)

{

	mutex_unlock(&probe_mutex);

}

static

int tp_list_show(struct seq_file *m, void *p)

{

	const struct lttng_event_desc *probe_desc = p;

	/*

	 * Don't export lttng internal events (metadata).

	 */

	if (!strncmp(probe_desc->name, "lttng_", sizeof("lttng_") - 1))

		return 0;

	seq_printf(m,	"event { name = %s; };\n",

		   probe_desc->name);

	return 0;

}

static

const struct seq_operations lttng_tracepoint_list_seq_ops = {

	.start = tp_list_start,

	.next = tp_list_next,

	.stop = tp_list_stop,

	.show = tp_list_show,

};

static

int lttng_tracepoint_list_open(struct inode *inode, struct file *file)

{

	return seq_open(file, &lttng_tracepoint_list_seq_ops);

}

const struct file_operations lttng_tracepoint_list_fops = {

	.owner = THIS_MODULE,

	.open = lttng_tracepoint_list_open,

	.read = seq_read,

	.llseek = seq_lseek,

	.release = seq_release,

};

#ifndef LTT_TRACER_CORE_H

#define LTT_TRACER_CORE_H

/*

 * ltt-tracer-core.h

 *

 * Copyright (C) 2005-2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

 *

 * This contains the core definitions for the Linux Trace Toolkit.

 *

 * Dual LGPL v2.1/GPL v2 license.

 */

#include <linux/list.h>

#include <linux/percpu.h>

#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS

/* Align data on its natural alignment */

#define RING_BUFFER_ALIGN

#endif

#include "wrapper/ringbuffer/config.h"

struct ltt_session;

struct ltt_channel;

struct ltt_event;

#endif /* LTT_TRACER_CORE_H */