From d7b645e2c77977a8a83362f27094bf6d126f6fb8 Mon Sep 17 00:00:00 2001 From: Jonathan Rajotte Date: Fri, 23 Oct 2015 11:32:44 -0400 Subject: [PATCH] Fix: load event state (enabled/disabled) correctly MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This bug fix is a workaround due to limitations of lttng_disable_event_ext regarding the disabling of events with similar name but different characteristics. Although lttng_disable_event_ext provides support for disabling by name and filter string it does not support exclusion. The loading of events is cut in 3 phases. 1 - Create all events regardless of their state. 2 - Disable all events. 3 - Enable only the events with the 'enabled' state. Fixes #959 Signed-off-by: Jonathan Rajotte Signed-off-by: Jérémie Galarneau --- src/common/config/session-config.c | 61 +++++++++++++++++++----------- 1 file changed, 39 insertions(+), 22 deletions(-) diff --git a/src/common/config/session-config.c b/src/common/config/session-config.c index 48094c59a..743b51438 100644 --- a/src/common/config/session-config.c +++ b/src/common/config/session-config.c @@ -177,6 +177,11 @@ LTTNG_HIDDEN const char * const config_event_context_preemptible = "PREEMPTIBLE" LTTNG_HIDDEN const char * const config_event_context_need_reschedule = "NEED_RESCHEDULE"; LTTNG_HIDDEN const char * const config_event_context_migratable = "MIGRATABLE"; +enum process_event_node_phase { + CREATION = 0, + ENABLE = 1, +}; + struct consumer_output { int enabled; char *path; @@ -1455,9 +1460,9 @@ end: static int process_event_node(xmlNodePtr event_node, struct lttng_handle *handle, - const char *channel_name) + const char *channel_name, const enum process_event_node_phase phase) { - int ret, i; + int ret = 0, i; xmlNodePtr node; struct lttng_event event; char **exclusions = NULL; @@ -1708,25 +1713,14 @@ int process_event_node(xmlNodePtr event_node, struct lttng_handle *handle, } } - ret = lttng_enable_event_with_exclusions(handle, &event, channel_name, - filter_expression, exclusion_count, exclusions); - if (ret) { - goto end; - } - - if (!event.enabled) { - /* - * Note that we should use lttng_disable_event_ext() (2.6+) to - * eliminate the risk of clashing on events of the same - * name (with different event types and loglevels). - * - * Unfortunately, lttng_disable_event_ext() only performs a - * match on the name and event type and errors out if any other - * event attribute is not set to its default value. - * - * This will disable all events that match this name. - */ - ret = lttng_disable_event(handle, event.name, channel_name); + if ((event.enabled && phase == ENABLE) || phase == CREATION) { + ret = lttng_enable_event_with_exclusions(handle, &event, channel_name, + filter_expression, exclusion_count, exclusions); + if (ret < 0) { + WARN("Enabling event (name:%s) on load failed.", event.name); + ret = -LTTNG_ERR_LOAD_INVALID_CONFIG; + goto end; + } } end: for (i = 0; i < exclusion_count; i++) { @@ -1743,6 +1737,7 @@ int process_events_node(xmlNodePtr events_node, struct lttng_handle *handle, const char *channel_name) { int ret = 0; + struct lttng_event event; xmlNodePtr node; assert(events_node); @@ -1751,11 +1746,33 @@ int process_events_node(xmlNodePtr events_node, struct lttng_handle *handle, for (node = xmlFirstElementChild(events_node); node; node = xmlNextElementSibling(node)) { - ret = process_event_node(node, handle, channel_name); + ret = process_event_node(node, handle, channel_name, CREATION); if (ret) { goto end; } } + + /* + * Disable all events to enable only the necessary events. + * Limitations regarding lttng_disable_events and tuple descriptor + * force this approach. + */ + memset(&event, 0, sizeof(event)); + event.loglevel = -1; + event.type = LTTNG_EVENT_ALL; + ret = lttng_disable_event_ext(handle, &event, channel_name, NULL); + if (ret) { + goto end; + } + + for (node = xmlFirstElementChild(events_node); node; + node = xmlNextElementSibling(node)) { + ret = process_event_node(node, handle, channel_name, ENABLE); + if (ret) { + goto end; + } + } + end: return ret; } -- 2.34.1