[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
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();

	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();

	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);

	lttng_probe_provider_unregister_events(desc);
	DBG("just unregistered probes of provider %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
71d31690 MD	150	static
	151	int check_provider_version(struct lttng_probe_desc *desc)
	152	{
	153	/*
	154	* Check tracepoint provider version compatibility.
	155	*/
	156	if (desc->major <= LTTNG_UST_PROVIDER_MAJOR) {
	157	DBG("Provider \"%s\" accepted, version %u.%u is compatible "
	158	"with LTTng UST provider version %u.%u.",
	159	desc->provider, desc->major, desc->minor,
	160	LTTNG_UST_PROVIDER_MAJOR,
	161	LTTNG_UST_PROVIDER_MINOR);
	162	if (desc->major < LTTNG_UST_PROVIDER_MAJOR) {
	163	DBG("However, some LTTng UST features might not be "
	164	"available for this provider unless it is "
	165	"recompiled against a more recent LTTng UST.");
	166	}
	167	return 1; /* accept */
	168	} else {
	169	ERR("Provider \"%s\" rejected, version %u.%u is incompatible "
	170	"with LTTng UST provider version %u.%u. Please upgrade "
	171	"LTTng UST.",
	172	desc->provider, desc->major, desc->minor,
	173	LTTNG_UST_PROVIDER_MAJOR,
	174	LTTNG_UST_PROVIDER_MINOR);
	175	return 0; /* reject */
	176	}
	177	}
	178
	179
6715d7d1 MD	180	int lttng_probe_register(struct lttng_probe_desc *desc)
	181	{
	182	int ret = 0;
	183
c362addf MD	184	lttng_ust_fixup_tls();
c362addf MD	185
71d31690 MD	186	/*
	187	* If version mismatch, don't register, but don't trigger assert
	188	* on caller. The version check just prints an error.
	189	*/
	190	if (!check_provider_version(desc))
	191	return 0;
	192
3327ac33	193	ust_lock_nocheck();
6715d7d1	194
6715d7d1 MD	195	cds_list_add(&desc->lazy_init_head, &lazy_probe_init);
	196	desc->lazy = 1;
	197	DBG("adding probe %s containing %u events to lazy registration list",
	198	desc->provider, desc->nr_events);
	199	/*
	200	* If there is at least one active session, we need to register
	201	* the probe immediately, since we cannot delay event
	202	* registration because they are needed ASAP.
	203	*/
	204	if (lttng_session_active())
	205	fixup_lazy_probes();
0fdd0b89	206
17dfb34b	207	ust_unlock();
ce5aef0b MD	208	return ret;
ce5aef0b MD	209	}
ce5aef0b	210
7dd08bec MD	211	/* Backward compatibility with UST 2.0 */
	212	int ltt_probe_register(struct lttng_probe_desc *desc)
	213	{
	214	return lttng_probe_register(desc);
	215	}
	216
	217	void lttng_probe_unregister(struct lttng_probe_desc *desc)
ce5aef0b	218	{
c362addf MD	219	lttng_ust_fixup_tls();
c362addf MD	220
71d31690 MD	221	if (!check_provider_version(desc))
	222	return;
	223
3327ac33	224	ust_lock_nocheck();
6715d7d1 MD	225	if (!desc->lazy)
	226	cds_list_del(&desc->head);
	227	else
	228	cds_list_del(&desc->lazy_init_head);
2c05c691 FD	229
	230	lttng_probe_provider_unregister_events(desc);
	231	DBG("just unregistered probes of provider %s", desc->provider);
	232
17dfb34b	233	ust_unlock();
ce5aef0b	234	}
ce5aef0b	235
7dd08bec MD	236	/* Backward compatibility with UST 2.0 */
	237	void ltt_probe_unregister(struct lttng_probe_desc *desc)
	238	{
	239	lttng_probe_unregister(desc);
	240	}
	241
7dd08bec	242	void lttng_probes_prune_event_list(struct lttng_ust_tracepoint_list *list)
c8fcf224 MD	243	{
	244	struct tp_list_entry list_entry, tmp;
	245
	246	cds_list_for_each_entry_safe(list_entry, tmp, &list->head, head) {
	247	cds_list_del(&list_entry->head);
	248	free(list_entry);
	249	}
	250	}
	251
	252	/*
	253	* called with UST lock held.
	254	*/
7dd08bec	255	int lttng_probes_get_event_list(struct lttng_ust_tracepoint_list *list)
c8fcf224 MD	256	{
	257	struct lttng_probe_desc *probe_desc;
	258	int i;
ac69b35b	259	struct cds_list_head *probe_list;
c8fcf224	260
ac69b35b	261	probe_list = lttng_get_probe_list_head();
c8fcf224	262	CDS_INIT_LIST_HEAD(&list->head);
ac69b35b	263	cds_list_for_each_entry(probe_desc, probe_list, head) {
c8fcf224 MD	264	for (i = 0; i < probe_desc->nr_events; i++) {
	265	struct tp_list_entry *list_entry;
	266
	267	list_entry = zmalloc(sizeof(*list_entry));
	268	if (!list_entry)
	269	goto err_nomem;
	270	cds_list_add(&list_entry->head, &list->head);
	271	strncpy(list_entry->tp.name,
	272	probe_desc->event_desc[i]->name,
	273	LTTNG_UST_SYM_NAME_LEN);
	274	list_entry->tp.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
	275	if (!probe_desc->event_desc[i]->loglevel) {
882a56d7	276	list_entry->tp.loglevel = TRACE_DEFAULT;
c8fcf224	277	} else {
882a56d7	278	list_entry->tp.loglevel = (probe_desc->event_desc[i]->loglevel);
c8fcf224 MD	279	}
	280	}
	281	}
	282	if (cds_list_empty(&list->head))
	283	list->iter = NULL;
	284	else
	285	list->iter =
	286	cds_list_first_entry(&list->head, struct tp_list_entry, head);
	287	return 0;
	288
	289	err_nomem:
7dd08bec	290	lttng_probes_prune_event_list(list);
c8fcf224 MD	291	return -ENOMEM;
	292	}
	293
	294	/*
	295	* Return current iteration position, advance internal iterator to next.
	296	* Return NULL if end of list.
	297	*/
	298	struct lttng_ust_tracepoint_iter *
	299	lttng_ust_tracepoint_list_get_iter_next(struct lttng_ust_tracepoint_list *list)
	300	{
	301	struct tp_list_entry *entry;
	302
	303	if (!list->iter)
	304	return NULL;
	305	entry = list->iter;
	306	if (entry->head.next == &list->head)
	307	list->iter = NULL;
	308	else
	309	list->iter = cds_list_entry(entry->head.next,
	310	struct tp_list_entry, head);
	311	return &entry->tp;
	312	}
1f18504e	313
7dd08bec	314	void lttng_probes_prune_field_list(struct lttng_ust_field_list *list)
06d4f27e MD	315	{
	316	struct tp_field_list_entry list_entry, tmp;
	317
	318	cds_list_for_each_entry_safe(list_entry, tmp, &list->head, head) {
	319	cds_list_del(&list_entry->head);
	320	free(list_entry);
	321	}
	322	}
	323
	324	/*
	325	* called with UST lock held.
	326	*/
7dd08bec	327	int lttng_probes_get_field_list(struct lttng_ust_field_list *list)
06d4f27e MD	328	{
	329	struct lttng_probe_desc *probe_desc;
	330	int i;
ac69b35b	331	struct cds_list_head *probe_list;
06d4f27e	332
ac69b35b	333	probe_list = lttng_get_probe_list_head();
06d4f27e	334	CDS_INIT_LIST_HEAD(&list->head);
ac69b35b	335	cds_list_for_each_entry(probe_desc, probe_list, head) {
06d4f27e MD	336	for (i = 0; i < probe_desc->nr_events; i++) {
	337	const struct lttng_event_desc *event_desc =
	338	probe_desc->event_desc[i];
	339	int j;
	340
26329f26 MD	341	if (event_desc->nr_fields == 0) {
	342	/* Events without fields. */
	343	struct tp_field_list_entry *list_entry;
	344
	345	list_entry = zmalloc(sizeof(*list_entry));
	346	if (!list_entry)
	347	goto err_nomem;
	348	cds_list_add(&list_entry->head, &list->head);
	349	strncpy(list_entry->field.event_name,
	350	event_desc->name,
	351	LTTNG_UST_SYM_NAME_LEN);
	352	list_entry->field.event_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
	353	list_entry->field.field_name[0] = '\0';
	354	list_entry->field.type = LTTNG_UST_FIELD_OTHER;
	355	if (!event_desc->loglevel) {
	356	list_entry->field.loglevel = TRACE_DEFAULT;
	357	} else {
	358	list_entry->field.loglevel = (event_desc->loglevel);
	359	}
	360	list_entry->field.nowrite = 1;
	361	}
	362
06d4f27e MD	363	for (j = 0; j < event_desc->nr_fields; j++) {
	364	const struct lttng_event_field *event_field =
	365	&event_desc->fields[j];
	366	struct tp_field_list_entry *list_entry;
	367
	368	list_entry = zmalloc(sizeof(*list_entry));
	369	if (!list_entry)
	370	goto err_nomem;
	371	cds_list_add(&list_entry->head, &list->head);
	372	strncpy(list_entry->field.event_name,
	373	event_desc->name,
	374	LTTNG_UST_SYM_NAME_LEN);
	375	list_entry->field.event_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
	376	strncpy(list_entry->field.field_name,
	377	event_field->name,
	378	LTTNG_UST_SYM_NAME_LEN);
	379	list_entry->field.field_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
40003310 MD	380	switch (event_field->type.atype) {
	381	case atype_integer:
	382	list_entry->field.type = LTTNG_UST_FIELD_INTEGER;
	383	break;
	384	case atype_string:
	385	list_entry->field.type = LTTNG_UST_FIELD_STRING;
	386	break;
	387	case atype_array:
	388	if (event_field->type.u.array.elem_type.atype != atype_integer
	389	\|\| event_field->type.u.array.elem_type.u.basic.integer.encoding == lttng_encode_none)
	390	list_entry->field.type = LTTNG_UST_FIELD_OTHER;
	391	else
	392	list_entry->field.type = LTTNG_UST_FIELD_STRING;
	393	break;
	394	case atype_sequence:
	395	if (event_field->type.u.sequence.elem_type.atype != atype_integer
	396	\|\| event_field->type.u.sequence.elem_type.u.basic.integer.encoding == lttng_encode_none)
	397	list_entry->field.type = LTTNG_UST_FIELD_OTHER;
	398	else
	399	list_entry->field.type = LTTNG_UST_FIELD_STRING;
	400	break;
	401	case atype_float:
	402	list_entry->field.type = LTTNG_UST_FIELD_FLOAT;
	403	break;
	404	case atype_enum:
	405	list_entry->field.type = LTTNG_UST_FIELD_ENUM;
	406	break;
	407	default:
	408	list_entry->field.type = LTTNG_UST_FIELD_OTHER;
	409	}
06d4f27e MD	410	if (!event_desc->loglevel) {
	411	list_entry->field.loglevel = TRACE_DEFAULT;
	412	} else {
	413	list_entry->field.loglevel = (event_desc->loglevel);
	414	}
180901e6	415	list_entry->field.nowrite = event_field->nowrite;
06d4f27e MD	416	}
	417	}
	418	}
	419	if (cds_list_empty(&list->head))
	420	list->iter = NULL;
	421	else
	422	list->iter =
	423	cds_list_first_entry(&list->head,
	424	struct tp_field_list_entry, head);
	425	return 0;
	426
	427	err_nomem:
7dd08bec	428	lttng_probes_prune_field_list(list);
06d4f27e MD	429	return -ENOMEM;
	430	}
	431
	432	/*
	433	* Return current iteration position, advance internal iterator to next.
	434	* Return NULL if end of list.
	435	*/
	436	struct lttng_ust_field_iter *
	437	lttng_ust_field_list_get_iter_next(struct lttng_ust_field_list *list)
	438	{
	439	struct tp_field_list_entry *entry;
	440
	441	if (!list->iter)
	442	return NULL;
	443	entry = list->iter;
	444	if (entry->head.next == &list->head)
	445	list->iter = NULL;
	446	else
	447	list->iter = cds_list_entry(entry->head.next,
	448	struct tp_field_list_entry, head);
	449	return &entry->field;
	450	}