[lttng-ust.git] / liblttng-ust / lttng-probes.c

/*
 * lttng-probes.c
 *
 * Holds LTTng probes registry.
 *
 * Copyright 2010-2012 (c) - 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
 */

#define _LGPL_SOURCE
#include <string.h>
#include <errno.h>
#include <urcu/list.h>
#include <urcu/hlist.h>
#include <lttng/ust-events.h>
#include <lttng/tracepoint.h>
#include "tracepoint-internal.h"
#include <assert.h>
#include <helper.h>
#include <ctype.h>

#include "lttng-tracer-core.h"
#include "jhash.h"
#include "error.h"

/*
 * probe list is protected by ust_lock()/ust_unlock().
 */
static CDS_LIST_HEAD(_probe_list);

/*
 * List of probes registered by not yet processed.
 */
static CDS_LIST_HEAD(lazy_probe_init);

/*
 * lazy_nesting counter ensures we don't trigger lazy probe registration
 * fixup while we are performing the fixup. It is protected by the ust
 * mutex.
 */
static int lazy_nesting;

/*
 * Called under ust lock.
 */
static
int check_event_provider(struct lttng_probe_desc *desc)
{
	int i;
	size_t provider_name_len;

	provider_name_len = strnlen(desc->provider,
				LTTNG_UST_SYM_NAME_LEN - 1);
	for (i = 0; i < desc->nr_events; i++) {
		if (strncmp(desc->event_desc[i]->name,
				desc->provider,
				provider_name_len))
			return 0;	/* provider mismatch */
	}
	return 1;
}

/*
 * Called under ust lock.
 */
static
void lttng_lazy_probe_register(struct lttng_probe_desc *desc)
{
	struct lttng_probe_desc *iter;
	struct cds_list_head *probe_list;

	/*
	 * Each provider enforce that every event name begins with the
	 * provider name. Check this in an assertion for extra
	 * carefulness. This ensures we cannot have duplicate event
	 * names across providers.
	 */
	assert(check_event_provider(desc));

	/*
	 * The provider ensures there are no duplicate event names.
	 * Duplicated TRACEPOINT_EVENT event names would generate a
	 * compile-time error due to duplicated symbol names.
	 */

	/*
	 * We sort the providers by struct lttng_probe_desc pointer
	 * address.
	 */
	probe_list = &_probe_list;
	cds_list_for_each_entry_reverse(iter, probe_list, head) {
		BUG_ON(iter == desc); /* Should never be in the list twice */
		if (iter < desc) {
			/* We belong to the location right after iter. */
			cds_list_add(&desc->head, &iter->head);
			goto desc_added;
		}
	}
	/* We should be added at the head of the list */
	cds_list_add(&desc->head, probe_list);
desc_added:
	DBG("just registered probe %s containing %u events",
		desc->provider, desc->nr_events);
}

/*
 * Called under ust lock.
 */
static
void fixup_lazy_probes(void)
{
	struct lttng_probe_desc *iter, *tmp;
	int ret;

	lazy_nesting++;
	cds_list_for_each_entry_safe(iter, tmp,
			&lazy_probe_init, lazy_init_head) {
		lttng_lazy_probe_register(iter);
		iter->lazy = 0;
		cds_list_del(&iter->lazy_init_head);
	}
	ret = lttng_fix_pending_events();
	assert(!ret);
	lazy_nesting--;
}

/*
 * Called under ust lock.
 */
struct cds_list_head *lttng_get_probe_list_head(void)
{
	if (!lazy_nesting && !cds_list_empty(&lazy_probe_init))
		fixup_lazy_probes();
	return &_probe_list;
}

static
const struct lttng_probe_desc *find_provider(const char *provider)
{
	struct lttng_probe_desc *iter;
	struct cds_list_head *probe_list;

	probe_list = lttng_get_probe_list_head();
	cds_list_for_each_entry(iter, probe_list, head) {
		if (!strcmp(iter->provider, provider))
			return iter;
	}
	return NULL;
}

static
int check_provider_version(struct lttng_probe_desc *desc)
{
	/*
	 * Check tracepoint provider version compatibility.
	 */
	if (desc->major <= LTTNG_UST_PROVIDER_MAJOR) {
		DBG("Provider \"%s\" accepted, version %u.%u is compatible "
			"with LTTng UST provider version %u.%u.",
			desc->provider, desc->major, desc->minor,
			LTTNG_UST_PROVIDER_MAJOR,
			LTTNG_UST_PROVIDER_MINOR);
		if (desc->major < LTTNG_UST_PROVIDER_MAJOR) {
			DBG("However, some LTTng UST features might not be "
				"available for this provider unless it is "
				"recompiled against a more recent LTTng UST.");
		}
		return 1;		/* accept */
	} else {
		ERR("Provider \"%s\" rejected, version %u.%u is incompatible "
			"with LTTng UST provider version %u.%u. Please upgrade "
			"LTTng UST.",
			desc->provider, desc->major, desc->minor,
			LTTNG_UST_PROVIDER_MAJOR,
			LTTNG_UST_PROVIDER_MINOR);
		return 0;		/* reject */
	}
}


int lttng_probe_register(struct lttng_probe_desc *desc)
{
	int ret = 0;

	lttng_ust_fixup_tls();

	/*
	 * If version mismatch, don't register, but don't trigger assert
	 * on caller. The version check just prints an error.
	 */
	if (!check_provider_version(desc))
		return 0;

	ust_lock_nocheck();

	/*
	 * Check if the provider has already been registered.
	 */
	if (find_provider(desc->provider)) {
		ret = -EEXIST;
		goto end;
	}
	cds_list_add(&desc->lazy_init_head, &lazy_probe_init);
	desc->lazy = 1;
	DBG("adding probe %s containing %u events to lazy registration list",
		desc->provider, desc->nr_events);
	/*
	 * If there is at least one active session, we need to register
	 * the probe immediately, since we cannot delay event
	 * registration because they are needed ASAP.
	 */
	if (lttng_session_active())
		fixup_lazy_probes();
end:
	ust_unlock();
	return ret;
}

/* Backward compatibility with UST 2.0 */
int ltt_probe_register(struct lttng_probe_desc *desc)
{
	return lttng_probe_register(desc);
}

void lttng_probe_unregister(struct lttng_probe_desc *desc)
{
	lttng_ust_fixup_tls();

	if (!check_provider_version(desc))
		return;

	ust_lock_nocheck();
	if (!desc->lazy)
		cds_list_del(&desc->head);
	else
		cds_list_del(&desc->lazy_init_head);
	DBG("just unregistered probe %s", desc->provider);
	ust_unlock();
}

/* Backward compatibility with UST 2.0 */
void ltt_probe_unregister(struct lttng_probe_desc *desc)
{
	lttng_probe_unregister(desc);
}

void lttng_probes_prune_event_list(struct lttng_ust_tracepoint_list *list)
{
	struct tp_list_entry *list_entry, *tmp;

	cds_list_for_each_entry_safe(list_entry, tmp, &list->head, head) {
		cds_list_del(&list_entry->head);
		free(list_entry);
	}
}

/*
 * called with UST lock held.
 */
int lttng_probes_get_event_list(struct lttng_ust_tracepoint_list *list)
{
	struct lttng_probe_desc *probe_desc;
	int i;
	struct cds_list_head *probe_list;

	probe_list = lttng_get_probe_list_head();
	CDS_INIT_LIST_HEAD(&list->head);
	cds_list_for_each_entry(probe_desc, probe_list, head) {
		for (i = 0; i < probe_desc->nr_events; i++) {
			struct tp_list_entry *list_entry;

			list_entry = zmalloc(sizeof(*list_entry));
			if (!list_entry)
				goto err_nomem;
			cds_list_add(&list_entry->head, &list->head);
			strncpy(list_entry->tp.name,
				probe_desc->event_desc[i]->name,
				LTTNG_UST_SYM_NAME_LEN);
			list_entry->tp.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
			if (!probe_desc->event_desc[i]->loglevel) {
				list_entry->tp.loglevel = TRACE_DEFAULT;
			} else {
				list_entry->tp.loglevel = *(*probe_desc->event_desc[i]->loglevel);
			}
		}
	}
	if (cds_list_empty(&list->head))
		list->iter = NULL;
	else
		list->iter =
			cds_list_first_entry(&list->head, struct tp_list_entry, head);
	return 0;

err_nomem:
	lttng_probes_prune_event_list(list);
	return -ENOMEM;
}

/*
 * Return current iteration position, advance internal iterator to next.
 * Return NULL if end of list.
 */
struct lttng_ust_tracepoint_iter *
	lttng_ust_tracepoint_list_get_iter_next(struct lttng_ust_tracepoint_list *list)
{
	struct tp_list_entry *entry;

	if (!list->iter)
		return NULL;
	entry = list->iter;
	if (entry->head.next == &list->head)
		list->iter = NULL;
	else
		list->iter = cds_list_entry(entry->head.next,
				struct tp_list_entry, head);
	return &entry->tp;
}

void lttng_probes_prune_field_list(struct lttng_ust_field_list *list)
{
	struct tp_field_list_entry *list_entry, *tmp;

	cds_list_for_each_entry_safe(list_entry, tmp, &list->head, head) {
		cds_list_del(&list_entry->head);
		free(list_entry);
	}
}

/*
 * called with UST lock held.
 */
int lttng_probes_get_field_list(struct lttng_ust_field_list *list)
{
	struct lttng_probe_desc *probe_desc;
	int i;
	struct cds_list_head *probe_list;

	probe_list = lttng_get_probe_list_head();
	CDS_INIT_LIST_HEAD(&list->head);
	cds_list_for_each_entry(probe_desc, probe_list, head) {
		for (i = 0; i < probe_desc->nr_events; i++) {
			const struct lttng_event_desc *event_desc =
				probe_desc->event_desc[i];
			int j;

			if (event_desc->nr_fields == 0) {
				/* Events without fields. */
				struct tp_field_list_entry *list_entry;

				list_entry = zmalloc(sizeof(*list_entry));
				if (!list_entry)
					goto err_nomem;
				cds_list_add(&list_entry->head, &list->head);
				strncpy(list_entry->field.event_name,
					event_desc->name,
					LTTNG_UST_SYM_NAME_LEN);
				list_entry->field.event_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
				list_entry->field.field_name[0] = '\0';
				list_entry->field.type = LTTNG_UST_FIELD_OTHER;
				if (!event_desc->loglevel) {
					list_entry->field.loglevel = TRACE_DEFAULT;
				} else {
					list_entry->field.loglevel = *(*event_desc->loglevel);
				}
				list_entry->field.nowrite = 1;
			}

			for (j = 0; j < event_desc->nr_fields; j++) {
				const struct lttng_event_field *event_field =
					&event_desc->fields[j];
				struct tp_field_list_entry *list_entry;

				list_entry = zmalloc(sizeof(*list_entry));
				if (!list_entry)
					goto err_nomem;
				cds_list_add(&list_entry->head, &list->head);
				strncpy(list_entry->field.event_name,
					event_desc->name,
					LTTNG_UST_SYM_NAME_LEN);
				list_entry->field.event_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
				strncpy(list_entry->field.field_name,
					event_field->name,
					LTTNG_UST_SYM_NAME_LEN);
				list_entry->field.field_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
				switch (event_field->type.atype) {
				case atype_integer:
					list_entry->field.type = LTTNG_UST_FIELD_INTEGER;
					break;
				case atype_string:
					list_entry->field.type = LTTNG_UST_FIELD_STRING;
					break;
				case atype_array:
					if (event_field->type.u.array.elem_type.atype != atype_integer
						|| event_field->type.u.array.elem_type.u.basic.integer.encoding == lttng_encode_none)
						list_entry->field.type = LTTNG_UST_FIELD_OTHER;
					else
						list_entry->field.type = LTTNG_UST_FIELD_STRING;
					break;
				case atype_sequence:
					if (event_field->type.u.sequence.elem_type.atype != atype_integer
						|| event_field->type.u.sequence.elem_type.u.basic.integer.encoding == lttng_encode_none)
						list_entry->field.type = LTTNG_UST_FIELD_OTHER;
					else
						list_entry->field.type = LTTNG_UST_FIELD_STRING;
					break;
				case atype_float:
					list_entry->field.type = LTTNG_UST_FIELD_FLOAT;
					break;
				case atype_enum:
					list_entry->field.type = LTTNG_UST_FIELD_ENUM;
					break;
				default:
					list_entry->field.type = LTTNG_UST_FIELD_OTHER;
				}
				if (!event_desc->loglevel) {
					list_entry->field.loglevel = TRACE_DEFAULT;
				} else {
					list_entry->field.loglevel = *(*event_desc->loglevel);
				}
				list_entry->field.nowrite = event_field->nowrite;
			}
		}
	}
	if (cds_list_empty(&list->head))
		list->iter = NULL;
	else
		list->iter =
			cds_list_first_entry(&list->head,
				struct tp_field_list_entry, head);
	return 0;

err_nomem:
	lttng_probes_prune_field_list(list);
	return -ENOMEM;
}

/*
 * Return current iteration position, advance internal iterator to next.
 * Return NULL if end of list.
 */
struct lttng_ust_field_iter *
	lttng_ust_field_list_get_iter_next(struct lttng_ust_field_list *list)
{
	struct tp_field_list_entry *entry;

	if (!list->iter)
		return NULL;
	entry = list->iter;
	if (entry->head.next == &list->head)
		list->iter = NULL;
	else
		list->iter = cds_list_entry(entry->head.next,
				struct tp_field_list_entry, head);
	return &entry->field;
}
Commit	Line	Data
ce5aef0b	1	/*
7dd08bec	2	* lttng-probes.c
ce5aef0b	3	*
ce5aef0b MD	4	* Holds LTTng probes registry.
ce5aef0b MD	5	*
e92f3e28 MD	6	* Copyright 2010-2012 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	7	*
	8	* This library is free software; you can redistribute it and/or
	9	* modify it under the terms of the GNU Lesser General Public
	10	* License as published by the Free Software Foundation; only
	11	* version 2.1 of the License.
	12	*
	13	* This library is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	16	* Lesser General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU Lesser General Public
	19	* License along with this library; if not, write to the Free Software
	20	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
ce5aef0b MD	21	*/
ce5aef0b MD	22
3fbec7dc	23	#define _LGPL_SOURCE
8d8a24c8 MD	24	#include <string.h>
	25	#include <errno.h>
	26	#include <urcu/list.h>
1f18504e	27	#include <urcu/hlist.h>
4318ae1b	28	#include <lttng/ust-events.h>
902e1379	29	#include <lttng/tracepoint.h>
d8de1354	30	#include "tracepoint-internal.h"
a3bb4b27	31	#include <assert.h>
c8fcf224	32	#include <helper.h>
48740cab	33	#include <ctype.h>
ce5aef0b	34
7dd08bec	35	#include "lttng-tracer-core.h"
1f18504e MD	36	#include "jhash.h"
1f18504e MD	37	#include "error.h"
8165c8da MD	38
8165c8da MD	39	/*
17dfb34b	40	* probe list is protected by ust_lock()/ust_unlock().
8165c8da	41	*/
ac69b35b	42	static CDS_LIST_HEAD(_probe_list);
e58095ef	43
6715d7d1 MD	44	/*
	45	* List of probes registered by not yet processed.
	46	*/
	47	static CDS_LIST_HEAD(lazy_probe_init);
df854e41	48
6715d7d1 MD	49	/*
	50	* lazy_nesting counter ensures we don't trigger lazy probe registration
	51	* fixup while we are performing the fixup. It is protected by the ust
	52	* mutex.
	53	*/
	54	static int lazy_nesting;
df854e41	55
6715d7d1 MD	56	/*
	57	* Called under ust lock.
	58	*/
ce5aef0b	59	static
48205d60	60	int check_event_provider(struct lttng_probe_desc *desc)
ce5aef0b	61	{
ce5aef0b	62	int i;
48205d60	63	size_t provider_name_len;
ce5aef0b	64
48205d60 MD	65	provider_name_len = strnlen(desc->provider,
	66	LTTNG_UST_SYM_NAME_LEN - 1);
	67	for (i = 0; i < desc->nr_events; i++) {
	68	if (strncmp(desc->event_desc[i]->name,
	69	desc->provider,
	70	provider_name_len))
	71	return 0; /* provider mismatch */
ce5aef0b	72	}
48205d60	73	return 1;
ce5aef0b MD	74	}
ce5aef0b MD	75
6715d7d1 MD	76	/*
	77	* Called under ust lock.
	78	*/
	79	static
	80	void lttng_lazy_probe_register(struct lttng_probe_desc *desc)
ce5aef0b	81	{
df854e41	82	struct lttng_probe_desc *iter;
ac69b35b	83	struct cds_list_head *probe_list;
48205d60	84
ce5aef0b	85	/*
48205d60 MD	86	* Each provider enforce that every event name begins with the
	87	* provider name. Check this in an assertion for extra
	88	* carefulness. This ensures we cannot have duplicate event
	89	* names across providers.
	90	*/
	91	assert(check_event_provider(desc));
	92
	93	/*
	94	* The provider ensures there are no duplicate event names.
	95	* Duplicated TRACEPOINT_EVENT event names would generate a
	96	* compile-time error due to duplicated symbol names.
ce5aef0b	97	*/
df854e41 MD	98
	99	/*
	100	* We sort the providers by struct lttng_probe_desc pointer
	101	* address.
	102	*/
6715d7d1	103	probe_list = &_probe_list;
ac69b35b	104	cds_list_for_each_entry_reverse(iter, probe_list, head) {
df854e41 MD	105	BUG_ON(iter == desc); /* Should never be in the list twice */
	106	if (iter < desc) {
	107	/* We belong to the location right after iter. */
	108	cds_list_add(&desc->head, &iter->head);
	109	goto desc_added;
	110	}
	111	}
	112	/* We should be added at the head of the list */
ac69b35b	113	cds_list_add(&desc->head, probe_list);
df854e41	114	desc_added:
e81a53af MD	115	DBG("just registered probe %s containing %u events",
e81a53af MD	116	desc->provider, desc->nr_events);
6715d7d1 MD	117	}
	118
	119	/*
	120	* Called under ust lock.
	121	*/
	122	static
	123	void fixup_lazy_probes(void)
	124	{
	125	struct lttng_probe_desc iter, tmp;
5f733922	126	int ret;
6715d7d1 MD	127
	128	lazy_nesting++;
	129	cds_list_for_each_entry_safe(iter, tmp,
	130	&lazy_probe_init, lazy_init_head) {
	131	lttng_lazy_probe_register(iter);
	132	iter->lazy = 0;
	133	cds_list_del(&iter->lazy_init_head);
	134	}
5f733922 MD	135	ret = lttng_fix_pending_events();
5f733922 MD	136	assert(!ret);
6715d7d1 MD	137	lazy_nesting--;
	138	}
	139
	140	/*
	141	* Called under ust lock.
	142	*/
	143	struct cds_list_head *lttng_get_probe_list_head(void)
	144	{
	145	if (!lazy_nesting && !cds_list_empty(&lazy_probe_init))
	146	fixup_lazy_probes();
	147	return &_probe_list;
	148	}
	149
	150	static
	151	const struct lttng_probe_desc find_provider(const char provider)
	152	{
	153	struct lttng_probe_desc *iter;
	154	struct cds_list_head *probe_list;
	155
	156	probe_list = lttng_get_probe_list_head();
	157	cds_list_for_each_entry(iter, probe_list, head) {
	158	if (!strcmp(iter->provider, provider))
	159	return iter;
	160	}
	161	return NULL;
	162	}
	163
71d31690 MD	164	static
	165	int check_provider_version(struct lttng_probe_desc *desc)
	166	{
	167	/*
	168	* Check tracepoint provider version compatibility.
	169	*/
	170	if (desc->major <= LTTNG_UST_PROVIDER_MAJOR) {
	171	DBG("Provider \"%s\" accepted, version %u.%u is compatible "
	172	"with LTTng UST provider version %u.%u.",
	173	desc->provider, desc->major, desc->minor,
	174	LTTNG_UST_PROVIDER_MAJOR,
	175	LTTNG_UST_PROVIDER_MINOR);
	176	if (desc->major < LTTNG_UST_PROVIDER_MAJOR) {
	177	DBG("However, some LTTng UST features might not be "
	178	"available for this provider unless it is "
	179	"recompiled against a more recent LTTng UST.");
	180	}
	181	return 1; /* accept */
	182	} else {
	183	ERR("Provider \"%s\" rejected, version %u.%u is incompatible "
	184	"with LTTng UST provider version %u.%u. Please upgrade "
	185	"LTTng UST.",
	186	desc->provider, desc->major, desc->minor,
	187	LTTNG_UST_PROVIDER_MAJOR,
	188	LTTNG_UST_PROVIDER_MINOR);
	189	return 0; /* reject */
	190	}
	191	}
	192
	193
6715d7d1 MD	194	int lttng_probe_register(struct lttng_probe_desc *desc)
	195	{
	196	int ret = 0;
	197
c362addf MD	198	lttng_ust_fixup_tls();
c362addf MD	199
71d31690 MD	200	/*
	201	* If version mismatch, don't register, but don't trigger assert
	202	* on caller. The version check just prints an error.
	203	*/
	204	if (!check_provider_version(desc))
	205	return 0;
	206
3327ac33	207	ust_lock_nocheck();
6715d7d1 MD	208
	209	/*
	210	* Check if the provider has already been registered.
	211	*/
	212	if (find_provider(desc->provider)) {
	213	ret = -EEXIST;
	214	goto end;
	215	}
	216	cds_list_add(&desc->lazy_init_head, &lazy_probe_init);
	217	desc->lazy = 1;
	218	DBG("adding probe %s containing %u events to lazy registration list",
	219	desc->provider, desc->nr_events);
	220	/*
	221	* If there is at least one active session, we need to register
	222	* the probe immediately, since we cannot delay event
	223	* registration because they are needed ASAP.
	224	*/
	225	if (lttng_session_active())
	226	fixup_lazy_probes();
ce5aef0b	227	end:
17dfb34b	228	ust_unlock();
ce5aef0b MD	229	return ret;
ce5aef0b MD	230	}
ce5aef0b	231
7dd08bec MD	232	/* Backward compatibility with UST 2.0 */
	233	int ltt_probe_register(struct lttng_probe_desc *desc)
	234	{
	235	return lttng_probe_register(desc);
	236	}
	237
	238	void lttng_probe_unregister(struct lttng_probe_desc *desc)
ce5aef0b	239	{
c362addf MD	240	lttng_ust_fixup_tls();
c362addf MD	241
71d31690 MD	242	if (!check_provider_version(desc))
	243	return;
	244
3327ac33	245	ust_lock_nocheck();
6715d7d1 MD	246	if (!desc->lazy)
	247	cds_list_del(&desc->head);
	248	else
	249	cds_list_del(&desc->lazy_init_head);
e81a53af	250	DBG("just unregistered probe %s", desc->provider);
17dfb34b	251	ust_unlock();
ce5aef0b	252	}
ce5aef0b	253
7dd08bec MD	254	/* Backward compatibility with UST 2.0 */
	255	void ltt_probe_unregister(struct lttng_probe_desc *desc)
	256	{
	257	lttng_probe_unregister(desc);
	258	}
	259
7dd08bec	260	void lttng_probes_prune_event_list(struct lttng_ust_tracepoint_list *list)
c8fcf224 MD	261	{
	262	struct tp_list_entry list_entry, tmp;
	263
	264	cds_list_for_each_entry_safe(list_entry, tmp, &list->head, head) {
	265	cds_list_del(&list_entry->head);
	266	free(list_entry);
	267	}
	268	}
	269
	270	/*
	271	* called with UST lock held.
	272	*/
7dd08bec	273	int lttng_probes_get_event_list(struct lttng_ust_tracepoint_list *list)
c8fcf224 MD	274	{
	275	struct lttng_probe_desc *probe_desc;
	276	int i;
ac69b35b	277	struct cds_list_head *probe_list;
c8fcf224	278
ac69b35b	279	probe_list = lttng_get_probe_list_head();
c8fcf224	280	CDS_INIT_LIST_HEAD(&list->head);
ac69b35b	281	cds_list_for_each_entry(probe_desc, probe_list, head) {
c8fcf224 MD	282	for (i = 0; i < probe_desc->nr_events; i++) {
	283	struct tp_list_entry *list_entry;
	284
	285	list_entry = zmalloc(sizeof(*list_entry));
	286	if (!list_entry)
	287	goto err_nomem;
	288	cds_list_add(&list_entry->head, &list->head);
	289	strncpy(list_entry->tp.name,
	290	probe_desc->event_desc[i]->name,
	291	LTTNG_UST_SYM_NAME_LEN);
	292	list_entry->tp.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
	293	if (!probe_desc->event_desc[i]->loglevel) {
882a56d7	294	list_entry->tp.loglevel = TRACE_DEFAULT;
c8fcf224	295	} else {
882a56d7	296	list_entry->tp.loglevel = (probe_desc->event_desc[i]->loglevel);
c8fcf224 MD	297	}
	298	}
	299	}
	300	if (cds_list_empty(&list->head))
	301	list->iter = NULL;
	302	else
	303	list->iter =
	304	cds_list_first_entry(&list->head, struct tp_list_entry, head);
	305	return 0;
	306
	307	err_nomem:
7dd08bec	308	lttng_probes_prune_event_list(list);
c8fcf224 MD	309	return -ENOMEM;
	310	}
	311
	312	/*
	313	* Return current iteration position, advance internal iterator to next.
	314	* Return NULL if end of list.
	315	*/
	316	struct lttng_ust_tracepoint_iter *
	317	lttng_ust_tracepoint_list_get_iter_next(struct lttng_ust_tracepoint_list *list)
	318	{
	319	struct tp_list_entry *entry;
	320
	321	if (!list->iter)
	322	return NULL;
	323	entry = list->iter;
	324	if (entry->head.next == &list->head)
	325	list->iter = NULL;
	326	else
	327	list->iter = cds_list_entry(entry->head.next,
	328	struct tp_list_entry, head);
	329	return &entry->tp;
	330	}
1f18504e	331
7dd08bec	332	void lttng_probes_prune_field_list(struct lttng_ust_field_list *list)
06d4f27e MD	333	{
	334	struct tp_field_list_entry list_entry, tmp;
	335
	336	cds_list_for_each_entry_safe(list_entry, tmp, &list->head, head) {
	337	cds_list_del(&list_entry->head);
	338	free(list_entry);
	339	}
	340	}
	341
	342	/*
	343	* called with UST lock held.
	344	*/
7dd08bec	345	int lttng_probes_get_field_list(struct lttng_ust_field_list *list)
06d4f27e MD	346	{
	347	struct lttng_probe_desc *probe_desc;
	348	int i;
ac69b35b	349	struct cds_list_head *probe_list;
06d4f27e	350
ac69b35b	351	probe_list = lttng_get_probe_list_head();
06d4f27e	352	CDS_INIT_LIST_HEAD(&list->head);
ac69b35b	353	cds_list_for_each_entry(probe_desc, probe_list, head) {
06d4f27e MD	354	for (i = 0; i < probe_desc->nr_events; i++) {
	355	const struct lttng_event_desc *event_desc =
	356	probe_desc->event_desc[i];
	357	int j;
	358
26329f26 MD	359	if (event_desc->nr_fields == 0) {
	360	/* Events without fields. */
	361	struct tp_field_list_entry *list_entry;
	362
	363	list_entry = zmalloc(sizeof(*list_entry));
	364	if (!list_entry)
	365	goto err_nomem;
	366	cds_list_add(&list_entry->head, &list->head);
	367	strncpy(list_entry->field.event_name,
	368	event_desc->name,
	369	LTTNG_UST_SYM_NAME_LEN);
	370	list_entry->field.event_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
	371	list_entry->field.field_name[0] = '\0';
	372	list_entry->field.type = LTTNG_UST_FIELD_OTHER;
	373	if (!event_desc->loglevel) {
	374	list_entry->field.loglevel = TRACE_DEFAULT;
	375	} else {
	376	list_entry->field.loglevel = (event_desc->loglevel);
	377	}
	378	list_entry->field.nowrite = 1;
	379	}
	380
06d4f27e MD	381	for (j = 0; j < event_desc->nr_fields; j++) {
	382	const struct lttng_event_field *event_field =
	383	&event_desc->fields[j];
	384	struct tp_field_list_entry *list_entry;
	385
	386	list_entry = zmalloc(sizeof(*list_entry));
	387	if (!list_entry)
	388	goto err_nomem;
	389	cds_list_add(&list_entry->head, &list->head);
	390	strncpy(list_entry->field.event_name,
	391	event_desc->name,
	392	LTTNG_UST_SYM_NAME_LEN);
	393	list_entry->field.event_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
	394	strncpy(list_entry->field.field_name,
	395	event_field->name,
	396	LTTNG_UST_SYM_NAME_LEN);
	397	list_entry->field.field_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
40003310 MD	398	switch (event_field->type.atype) {
	399	case atype_integer:
	400	list_entry->field.type = LTTNG_UST_FIELD_INTEGER;
	401	break;
	402	case atype_string:
	403	list_entry->field.type = LTTNG_UST_FIELD_STRING;
	404	break;
	405	case atype_array:
	406	if (event_field->type.u.array.elem_type.atype != atype_integer
	407	\|\| event_field->type.u.array.elem_type.u.basic.integer.encoding == lttng_encode_none)
	408	list_entry->field.type = LTTNG_UST_FIELD_OTHER;
	409	else
	410	list_entry->field.type = LTTNG_UST_FIELD_STRING;
	411	break;
	412	case atype_sequence:
	413	if (event_field->type.u.sequence.elem_type.atype != atype_integer
	414	\|\| event_field->type.u.sequence.elem_type.u.basic.integer.encoding == lttng_encode_none)
	415	list_entry->field.type = LTTNG_UST_FIELD_OTHER;
	416	else
	417	list_entry->field.type = LTTNG_UST_FIELD_STRING;
	418	break;
	419	case atype_float:
	420	list_entry->field.type = LTTNG_UST_FIELD_FLOAT;
	421	break;
	422	case atype_enum:
	423	list_entry->field.type = LTTNG_UST_FIELD_ENUM;
	424	break;
	425	default:
	426	list_entry->field.type = LTTNG_UST_FIELD_OTHER;
	427	}
06d4f27e MD	428	if (!event_desc->loglevel) {
	429	list_entry->field.loglevel = TRACE_DEFAULT;
	430	} else {
	431	list_entry->field.loglevel = (event_desc->loglevel);
	432	}
180901e6	433	list_entry->field.nowrite = event_field->nowrite;
06d4f27e MD	434	}
	435	}
	436	}
	437	if (cds_list_empty(&list->head))
	438	list->iter = NULL;
	439	else
	440	list->iter =
	441	cds_list_first_entry(&list->head,
	442	struct tp_field_list_entry, head);
	443	return 0;
	444
	445	err_nomem:
7dd08bec	446	lttng_probes_prune_field_list(list);
06d4f27e MD	447	return -ENOMEM;
	448	}
	449
	450	/*
	451	* Return current iteration position, advance internal iterator to next.
	452	* Return NULL if end of list.
	453	*/
	454	struct lttng_ust_field_iter *
	455	lttng_ust_field_list_get_iter_next(struct lttng_ust_field_list *list)
	456	{
	457	struct tp_field_list_entry *entry;
	458
	459	if (!list->iter)
	460	return NULL;
	461	entry = list->iter;
	462	if (entry->head.next == &list->head)
	463	list->iter = NULL;
	464	else
	465	list->iter = cds_list_entry(entry->head.next,
	466	struct tp_field_list_entry, head);
	467	return &entry->field;
	468	}