X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;ds=sidebyside;f=liblttng-ust%2Flttng-probes.c;h=e7dab9fce49c2603392a9362311aff3a88ee39d3;hb=c0c0989ab70574e09b2f7e8b48c2da6af664a849;hp=9d7d83ceab716c62687bef3801ab0b59c6a56a0d;hpb=e58095efc3a51a505fc533e3e56b9b5ed8743a8b;p=lttng-ust.git diff --git a/liblttng-ust/lttng-probes.c b/liblttng-ust/lttng-probes.c index 9d7d83ce..e7dab9fc 100644 --- a/liblttng-ust/lttng-probes.c +++ b/liblttng-ust/lttng-probes.c @@ -1,25 +1,12 @@ /* - * lttng-probes.c + * SPDX-License-Identifier: LGPL-2.1-only * - * Holds LTTng probes registry. - * - * Copyright 2010-2012 (c) - Mathieu Desnoyers - * - * 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. + * Copyright 2010-2012 (C) Mathieu Desnoyers * - * 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 + * Holds LTTng probes registry. */ +#define _LGPL_SOURCE #include #include #include @@ -34,72 +21,74 @@ #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(). */ -CDS_LIST_HEAD(probe_list); - -struct cds_list_head *lttng_get_probe_list_head(void) -{ - return &probe_list; -} +static CDS_LIST_HEAD(_probe_list); -static -const struct lttng_probe_desc *find_provider(const char *provider) -{ - struct lttng_probe_desc *iter; +/* + * List of probes registered by not yet processed. + */ +static CDS_LIST_HEAD(lazy_probe_init); - cds_list_for_each_entry(iter, &probe_list, head) { - if (!strcmp(iter->provider, provider)) - return iter; - } - return NULL; -} +/* + * 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 -const struct lttng_event_desc *find_event(const char *name) +int check_event_provider(struct lttng_probe_desc *desc) { - struct lttng_probe_desc *probe_desc; int i; + size_t provider_name_len; - cds_list_for_each_entry(probe_desc, &probe_list, head) { - for (i = 0; i < probe_desc->nr_events; i++) { - if (!strncmp(probe_desc->event_desc[i]->name, name, - LTTNG_UST_SYM_NAME_LEN - 1)) - return probe_desc->event_desc[i]; - } + 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 NULL; + return 1; } -int lttng_probe_register(struct lttng_probe_desc *desc) +/* + * Called under ust lock. + */ +static +void lttng_lazy_probe_register(struct lttng_probe_desc *desc) { struct lttng_probe_desc *iter; - int ret = 0; - int i; + struct cds_list_head *probe_list; - ust_lock(); - if (find_provider(desc->provider)) { - ret = -EEXIST; - goto end; - } /* - * TODO: This is O(N^2). Turn into a hash table when probe registration - * overhead becomes an issue. + * 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. */ - for (i = 0; i < desc->nr_events; i++) { - if (find_event(desc->event_desc[i]->name)) { - ret = -EEXIST; - goto end; - } - } /* * We sort the providers by struct lttng_probe_desc pointer * address. */ - cds_list_for_each_entry_reverse(iter, &probe_list, head) { + 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. */ @@ -108,62 +97,123 @@ int lttng_probe_register(struct lttng_probe_desc *desc) } } /* We should be added at the head of the list */ - cds_list_add(&desc->head, &probe_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; - - 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); - } -end: - ust_unlock(); - return ret; } -/* Backward compatibility with UST 2.0 */ -int ltt_probe_register(struct lttng_probe_desc *desc) +/* + * Called under ust lock. + */ +static +void fixup_lazy_probes(void) { - return lttng_probe_register(desc); + 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--; } -void lttng_probe_unregister(struct lttng_probe_desc *desc) +/* + * Called under ust lock. + */ +struct cds_list_head *lttng_get_probe_list_head(void) { - ust_lock(); - cds_list_del(&desc->head); - DBG("just unregistered probe %s", desc->provider); - ust_unlock(); + if (!lazy_nesting && !cds_list_empty(&lazy_probe_init)) + fixup_lazy_probes(); + return &_probe_list; } -/* Backward compatibility with UST 2.0 */ -void ltt_probe_unregister(struct lttng_probe_desc *desc) +static +int check_provider_version(struct lttng_probe_desc *desc) { - lttng_probe_unregister(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 */ + } } -/* - * called with UST lock held. - */ -const struct lttng_event_desc *lttng_event_get(const char *name) + +int lttng_probe_register(struct lttng_probe_desc *desc) { - const struct lttng_event_desc *event; + int ret = 0; - event = find_event(name); - if (!event) - return NULL; - return event; + 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; } -void lttng_event_put(const struct lttng_event_desc *event) +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(); } void lttng_probes_prune_event_list(struct lttng_ust_tracepoint_list *list) @@ -183,9 +233,11 @@ 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) { + 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; @@ -253,9 +305,11 @@ 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) { + 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]; @@ -308,15 +362,29 @@ int lttng_probes_get_field_list(struct lttng_ust_field_list *list) 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) + 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.sequence.elem_type.atype != atype_integer - || event_field->type.u.sequence.elem_type.u.basic.integer.encoding == lttng_encode_none) + 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; @@ -324,7 +392,8 @@ int lttng_probes_get_field_list(struct lttng_ust_field_list *list) case atype_float: list_entry->field.type = LTTNG_UST_FIELD_FLOAT; break; - case atype_enum: + case atype_enum: /* Fall-through */ + case atype_enum_nestable: list_entry->field.type = LTTNG_UST_FIELD_ENUM; break; default: