+++ /dev/null
-/*
- * 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"
-#include "ust-events-internal.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();
-
- lttng_fix_pending_event_notifiers();
-
- 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.legacy.array.elem_type.atype != atype_integer
- || event_field->type.u.legacy.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_array_nestable:
- if (event_field->type.u.array_nestable.elem_type->atype != atype_integer
- || event_field->type.u.array_nestable.elem_type->u.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.legacy.sequence.elem_type.atype != atype_integer
- || event_field->type.u.legacy.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_sequence_nestable:
- if (event_field->type.u.sequence_nestable.elem_type->atype != atype_integer
- || event_field->type.u.sequence_nestable.elem_type->u.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: /* Fall-through */
- case atype_enum_nestable:
- 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;
-}
projects / lttng-ust.git / blobdiff