[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
 */

#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;
	int i;

	/*
	 * 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);
	/*
	 * fix the events awaiting probe load.
	 */
	for (i = 0; i < desc->nr_events; i++) {
		const struct lttng_event_desc *ed;
		int ret;

		ed = desc->event_desc[i];
		DBG("Registered event probe \"%s\" with signature \"%s\"",
			ed->name, ed->signature);
		ret = lttng_fix_pending_event_desc(ed);
		assert(!ret);
	}
}

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

	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);
	}
	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;
}

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

	ust_lock();

	/*
	 * 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)
{
	ust_lock();
	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
8d8a24c8 MD	23	#include <string.h>
	24	#include <errno.h>
	25	#include <urcu/list.h>
1f18504e	26	#include <urcu/hlist.h>
4318ae1b	27	#include <lttng/ust-events.h>
902e1379	28	#include <lttng/tracepoint.h>
d8de1354	29	#include "tracepoint-internal.h"
a3bb4b27	30	#include <assert.h>
c8fcf224	31	#include <helper.h>
48740cab	32	#include <ctype.h>
ce5aef0b	33
7dd08bec	34	#include "lttng-tracer-core.h"
1f18504e MD	35	#include "jhash.h"
1f18504e MD	36	#include "error.h"
8165c8da MD	37
8165c8da MD	38	/*
17dfb34b	39	* probe list is protected by ust_lock()/ust_unlock().
8165c8da	40	*/
ac69b35b	41	static CDS_LIST_HEAD(_probe_list);
e58095ef	42
6715d7d1 MD	43	/*
	44	* List of probes registered by not yet processed.
	45	*/
	46	static CDS_LIST_HEAD(lazy_probe_init);
df854e41	47
6715d7d1 MD	48	/*
	49	* lazy_nesting counter ensures we don't trigger lazy probe registration
	50	* fixup while we are performing the fixup. It is protected by the ust
	51	* mutex.
	52	*/
	53	static int lazy_nesting;
df854e41	54
6715d7d1 MD	55	/*
	56	* Called under ust lock.
	57	*/
ce5aef0b	58	static
48205d60	59	int check_event_provider(struct lttng_probe_desc *desc)
ce5aef0b	60	{
ce5aef0b	61	int i;
48205d60	62	size_t provider_name_len;
ce5aef0b	63
48205d60 MD	64	provider_name_len = strnlen(desc->provider,
	65	LTTNG_UST_SYM_NAME_LEN - 1);
	66	for (i = 0; i < desc->nr_events; i++) {
	67	if (strncmp(desc->event_desc[i]->name,
	68	desc->provider,
	69	provider_name_len))
	70	return 0; /* provider mismatch */
ce5aef0b	71	}
48205d60	72	return 1;
ce5aef0b MD	73	}
ce5aef0b MD	74
6715d7d1 MD	75	/*
	76	* Called under ust lock.
	77	*/
	78	static
	79	void lttng_lazy_probe_register(struct lttng_probe_desc *desc)
ce5aef0b	80	{
df854e41	81	struct lttng_probe_desc *iter;
ac69b35b	82	struct cds_list_head *probe_list;
6715d7d1	83	int i;
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);
8165c8da MD	117	/*
	118	* fix the events awaiting probe load.
	119	*/
	120	for (i = 0; i < desc->nr_events; i++) {
68755429	121	const struct lttng_event_desc *ed;
6715d7d1	122	int ret;
68755429 MD	123
	124	ed = desc->event_desc[i];
	125	DBG("Registered event probe \"%s\" with signature \"%s\"",
	126	ed->name, ed->signature);
e58095ef	127	ret = lttng_fix_pending_event_desc(ed);
8165c8da MD	128	assert(!ret);
8165c8da MD	129	}
6715d7d1 MD	130	}
	131
	132	/*
	133	* Called under ust lock.
	134	*/
	135	static
	136	void fixup_lazy_probes(void)
	137	{
	138	struct lttng_probe_desc iter, tmp;
	139
	140	lazy_nesting++;
	141	cds_list_for_each_entry_safe(iter, tmp,
	142	&lazy_probe_init, lazy_init_head) {
	143	lttng_lazy_probe_register(iter);
	144	iter->lazy = 0;
	145	cds_list_del(&iter->lazy_init_head);
	146	}
	147	lazy_nesting--;
	148	}
	149
	150	/*
	151	* Called under ust lock.
	152	*/
	153	struct cds_list_head *lttng_get_probe_list_head(void)
	154	{
	155	if (!lazy_nesting && !cds_list_empty(&lazy_probe_init))
	156	fixup_lazy_probes();
	157	return &_probe_list;
	158	}
	159
	160	static
	161	const struct lttng_probe_desc find_provider(const char provider)
	162	{
	163	struct lttng_probe_desc *iter;
	164	struct cds_list_head *probe_list;
	165
	166	probe_list = lttng_get_probe_list_head();
	167	cds_list_for_each_entry(iter, probe_list, head) {
	168	if (!strcmp(iter->provider, provider))
	169	return iter;
	170	}
	171	return NULL;
	172	}
	173
	174	int lttng_probe_register(struct lttng_probe_desc *desc)
	175	{
	176	int ret = 0;
	177
	178	ust_lock();
	179
	180	/*
	181	* Check if the provider has already been registered.
	182	*/
	183	if (find_provider(desc->provider)) {
	184	ret = -EEXIST;
	185	goto end;
	186	}
	187	cds_list_add(&desc->lazy_init_head, &lazy_probe_init);
	188	desc->lazy = 1;
	189	DBG("adding probe %s containing %u events to lazy registration list",
	190	desc->provider, desc->nr_events);
	191	/*
	192	* If there is at least one active session, we need to register
	193	* the probe immediately, since we cannot delay event
194	* registration because they are needed ASAP.
195	*/
196	if (lttng_session_active())
197	fixup_lazy_probes();
ce5aef0b	198	end:
17dfb34b	199	ust_unlock();
ce5aef0b MD	200	return ret;
ce5aef0b MD	201	}
ce5aef0b	202
7dd08bec MD	203	/* Backward compatibility with UST 2.0 */
	204	int ltt_probe_register(struct lttng_probe_desc *desc)
	205	{
	206	return lttng_probe_register(desc);
	207	}
	208
	209	void lttng_probe_unregister(struct lttng_probe_desc *desc)
ce5aef0b	210	{
17dfb34b	211	ust_lock();
6715d7d1 MD	212	if (!desc->lazy)
	213	cds_list_del(&desc->head);
	214	else
	215	cds_list_del(&desc->lazy_init_head);
e81a53af	216	DBG("just unregistered probe %s", desc->provider);
17dfb34b	217	ust_unlock();
ce5aef0b	218	}
ce5aef0b	219
7dd08bec MD	220	/* Backward compatibility with UST 2.0 */
	221	void ltt_probe_unregister(struct lttng_probe_desc *desc)
	222	{
	223	lttng_probe_unregister(desc);
	224	}
	225
7dd08bec	226	void lttng_probes_prune_event_list(struct lttng_ust_tracepoint_list *list)
c8fcf224 MD	227	{
	228	struct tp_list_entry list_entry, tmp;
	229
	230	cds_list_for_each_entry_safe(list_entry, tmp, &list->head, head) {
	231	cds_list_del(&list_entry->head);
	232	free(list_entry);
	233	}
	234	}
	235
	236	/*
	237	* called with UST lock held.
	238	*/
7dd08bec	239	int lttng_probes_get_event_list(struct lttng_ust_tracepoint_list *list)
c8fcf224 MD	240	{
	241	struct lttng_probe_desc *probe_desc;
	242	int i;
ac69b35b	243	struct cds_list_head *probe_list;
c8fcf224	244
ac69b35b	245	probe_list = lttng_get_probe_list_head();
c8fcf224	246	CDS_INIT_LIST_HEAD(&list->head);
ac69b35b	247	cds_list_for_each_entry(probe_desc, probe_list, head) {
c8fcf224 MD	248	for (i = 0; i < probe_desc->nr_events; i++) {
	249	struct tp_list_entry *list_entry;
	250
	251	list_entry = zmalloc(sizeof(*list_entry));
	252	if (!list_entry)
	253	goto err_nomem;
	254	cds_list_add(&list_entry->head, &list->head);
	255	strncpy(list_entry->tp.name,
	256	probe_desc->event_desc[i]->name,
	257	LTTNG_UST_SYM_NAME_LEN);
	258	list_entry->tp.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
	259	if (!probe_desc->event_desc[i]->loglevel) {
882a56d7	260	list_entry->tp.loglevel = TRACE_DEFAULT;
c8fcf224	261	} else {
882a56d7	262	list_entry->tp.loglevel = (probe_desc->event_desc[i]->loglevel);
c8fcf224 MD	263	}
	264	}
	265	}
	266	if (cds_list_empty(&list->head))
	267	list->iter = NULL;
	268	else
	269	list->iter =
	270	cds_list_first_entry(&list->head, struct tp_list_entry, head);
	271	return 0;
	272
	273	err_nomem:
7dd08bec	274	lttng_probes_prune_event_list(list);
c8fcf224 MD	275	return -ENOMEM;
	276	}
	277
	278	/*
	279	* Return current iteration position, advance internal iterator to next.
	280	* Return NULL if end of list.
	281	*/
	282	struct lttng_ust_tracepoint_iter *
	283	lttng_ust_tracepoint_list_get_iter_next(struct lttng_ust_tracepoint_list *list)
	284	{
	285	struct tp_list_entry *entry;
	286
	287	if (!list->iter)
	288	return NULL;
	289	entry = list->iter;
	290	if (entry->head.next == &list->head)
	291	list->iter = NULL;
	292	else
	293	list->iter = cds_list_entry(entry->head.next,
	294	struct tp_list_entry, head);
	295	return &entry->tp;
	296	}
1f18504e	297
7dd08bec	298	void lttng_probes_prune_field_list(struct lttng_ust_field_list *list)
06d4f27e MD	299	{
	300	struct tp_field_list_entry list_entry, tmp;
	301
	302	cds_list_for_each_entry_safe(list_entry, tmp, &list->head, head) {
	303	cds_list_del(&list_entry->head);
	304	free(list_entry);
	305	}
	306	}
	307
	308	/*
	309	* called with UST lock held.
	310	*/
7dd08bec	311	int lttng_probes_get_field_list(struct lttng_ust_field_list *list)
06d4f27e MD	312	{
	313	struct lttng_probe_desc *probe_desc;
	314	int i;
ac69b35b	315	struct cds_list_head *probe_list;
06d4f27e	316
ac69b35b	317	probe_list = lttng_get_probe_list_head();
06d4f27e	318	CDS_INIT_LIST_HEAD(&list->head);
ac69b35b	319	cds_list_for_each_entry(probe_desc, probe_list, head) {
06d4f27e MD	320	for (i = 0; i < probe_desc->nr_events; i++) {
	321	const struct lttng_event_desc *event_desc =
	322	probe_desc->event_desc[i];
	323	int j;
	324
26329f26 MD	325	if (event_desc->nr_fields == 0) {
	326	/* Events without fields. */
	327	struct tp_field_list_entry *list_entry;
	328
	329	list_entry = zmalloc(sizeof(*list_entry));
	330	if (!list_entry)
	331	goto err_nomem;
	332	cds_list_add(&list_entry->head, &list->head);
	333	strncpy(list_entry->field.event_name,
	334	event_desc->name,
	335	LTTNG_UST_SYM_NAME_LEN);
	336	list_entry->field.event_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
	337	list_entry->field.field_name[0] = '\0';
	338	list_entry->field.type = LTTNG_UST_FIELD_OTHER;
	339	if (!event_desc->loglevel) {
	340	list_entry->field.loglevel = TRACE_DEFAULT;
	341	} else {
	342	list_entry->field.loglevel = (event_desc->loglevel);
	343	}
	344	list_entry->field.nowrite = 1;
	345	}
	346
06d4f27e MD	347	for (j = 0; j < event_desc->nr_fields; j++) {
	348	const struct lttng_event_field *event_field =
	349	&event_desc->fields[j];
	350	struct tp_field_list_entry *list_entry;
	351
	352	list_entry = zmalloc(sizeof(*list_entry));
	353	if (!list_entry)
	354	goto err_nomem;
	355	cds_list_add(&list_entry->head, &list->head);
	356	strncpy(list_entry->field.event_name,
	357	event_desc->name,
	358	LTTNG_UST_SYM_NAME_LEN);
	359	list_entry->field.event_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
	360	strncpy(list_entry->field.field_name,
	361	event_field->name,
	362	LTTNG_UST_SYM_NAME_LEN);
	363	list_entry->field.field_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
40003310 MD	364	switch (event_field->type.atype) {
	365	case atype_integer:
	366	list_entry->field.type = LTTNG_UST_FIELD_INTEGER;
	367	break;
	368	case atype_string:
	369	list_entry->field.type = LTTNG_UST_FIELD_STRING;
	370	break;
	371	case atype_array:
	372	if (event_field->type.u.array.elem_type.atype != atype_integer
	373	\|\| event_field->type.u.array.elem_type.u.basic.integer.encoding == lttng_encode_none)
	374	list_entry->field.type = LTTNG_UST_FIELD_OTHER;
	375	else
	376	list_entry->field.type = LTTNG_UST_FIELD_STRING;
	377	break;
	378	case atype_sequence:
	379	if (event_field->type.u.sequence.elem_type.atype != atype_integer
	380	\|\| event_field->type.u.sequence.elem_type.u.basic.integer.encoding == lttng_encode_none)
	381	list_entry->field.type = LTTNG_UST_FIELD_OTHER;
	382	else
	383	list_entry->field.type = LTTNG_UST_FIELD_STRING;
	384	break;
	385	case atype_float:
	386	list_entry->field.type = LTTNG_UST_FIELD_FLOAT;
	387	break;
	388	case atype_enum:
	389	list_entry->field.type = LTTNG_UST_FIELD_ENUM;
	390	break;
	391	default:
	392	list_entry->field.type = LTTNG_UST_FIELD_OTHER;
	393	}
06d4f27e MD	394	if (!event_desc->loglevel) {
	395	list_entry->field.loglevel = TRACE_DEFAULT;
	396	} else {
	397	list_entry->field.loglevel = (event_desc->loglevel);
	398	}
180901e6	399	list_entry->field.nowrite = event_field->nowrite;
06d4f27e MD	400	}
	401	}
	402	}
	403	if (cds_list_empty(&list->head))
	404	list->iter = NULL;
	405	else
	406	list->iter =
	407	cds_list_first_entry(&list->head,
	408	struct tp_field_list_entry, head);
	409	return 0;
	410
	411	err_nomem:
7dd08bec	412	lttng_probes_prune_field_list(list);
06d4f27e MD	413	return -ENOMEM;
	414	}
	415
	416	/*
	417	* Return current iteration position, advance internal iterator to next.
	418	* Return NULL if end of list.
	419	*/
	420	struct lttng_ust_field_iter *
	421	lttng_ust_field_list_get_iter_next(struct lttng_ust_field_list *list)
	422	{
	423	struct tp_field_list_entry *entry;
	424
	425	if (!list->iter)
	426	return NULL;
	427	entry = list->iter;
	428	if (entry->head.next == &list->head)
	429	list->iter = NULL;
	430	else
	431	list->iter = cds_list_entry(entry->head.next,
	432	struct tp_field_list_entry, head);
	433	return &entry->field;
	434	}