Fix: leak of filter bytecode and expression on agent event re-enable
[lttng-tools.git] / src / bin / lttng-sessiond / event.c
index 8727dfd9a62ff33ed019a825da57149274a02a80..b0b37bed777a4eb5b537b0739c14115b5e3020a2 100644 (file)
@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
+ * Copyright (C) 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License, version 2 only,
@@ -15,7 +16,6 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
-#define _GNU_SOURCE
 #define _LGPL_SOURCE
 #include <errno.h>
 #include <urcu/list.h>
@@ -24,6 +24,8 @@
 #include <lttng/lttng.h>
 #include <common/error.h>
 #include <common/sessiond-comm/sessiond-comm.h>
+#include <common/filter.h>
+#include <common/context.h>
 
 #include "channel.h"
 #include "event.h"
@@ -50,7 +52,8 @@ static void add_unique_ust_event(struct lttng_ht *ht,
 
        key.name = event->attr.name;
        key.filter = (struct lttng_filter_bytecode *) event->filter;
-       key.loglevel = event->attr.loglevel;
+       key.loglevel_type = event->attr.loglevel_type;
+       key.loglevel_value = event->attr.loglevel;
        key.exclusion = event->exclusion;
 
        node_ptr = cds_lfht_add_unique(ht->ht,
@@ -60,45 +63,15 @@ static void add_unique_ust_event(struct lttng_ht *ht,
 }
 
 /*
- * Disable kernel tracepoint event for a channel from the kernel session.
+ * Disable kernel tracepoint events for a channel from the kernel session of
+ * a specified event_name and event type.
+ * On type LTTNG_EVENT_ALL all events with event_name are disabled.
+ * If event_name is NULL all events of the specified type are disabled.
  */
 int event_kernel_disable_event(struct ltt_kernel_channel *kchan,
-               char *event_name)
+               char *event_name, enum lttng_event_type type)
 {
-       int ret;
-       struct ltt_kernel_event *kevent;
-
-       assert(kchan);
-
-       kevent = trace_kernel_get_event_by_name(event_name, kchan,
-                       LTTNG_EVENT_ALL);
-       if (kevent == NULL) {
-               ret = LTTNG_ERR_NO_EVENT;
-               goto error;
-       }
-
-       ret = kernel_disable_event(kevent);
-       if (ret < 0) {
-               ret = LTTNG_ERR_KERN_DISABLE_FAIL;
-               goto error;
-       }
-
-       DBG("Kernel event %s disable for channel %s.",
-                       kevent->event->name, kchan->channel->name);
-
-       ret = LTTNG_OK;
-
-error:
-       return ret;
-}
-
-/*
- * Disable kernel tracepoint events for a channel from the kernel session.
- */
-int event_kernel_disable_event_type(struct ltt_kernel_channel *kchan,
-               enum lttng_event_type type)
-{
-       int ret;
+       int ret, error = 0, found = 0;
        struct ltt_kernel_event *kevent;
 
        assert(kchan);
@@ -107,22 +80,26 @@ int event_kernel_disable_event_type(struct ltt_kernel_channel *kchan,
        cds_list_for_each_entry(kevent, &kchan->events_list.head, list) {
                if (type != LTTNG_EVENT_ALL && kevent->type != type)
                        continue;
+               if (event_name != NULL && strcmp(event_name, kevent->event->name)) {
+                       continue;
+               }
+               found++;
                ret = kernel_disable_event(kevent);
                if (ret < 0) {
-                       /* We continue disabling the rest */
+                       error = 1;
                        continue;
                }
        }
-       ret = LTTNG_OK;
-       return ret;
-}
+       DBG("Disable kernel event: found %d events with name: %s and type: %d",
+                       found, event_name ? event_name : "NULL", type);
 
-/*
- * Disable all kernel event for a channel from the kernel session.
- */
-int event_kernel_disable_event_all(struct ltt_kernel_channel *kchan)
-{
-       return event_kernel_disable_event_type(kchan, LTTNG_EVENT_ALL);
+       if (event_name != NULL && !found) {
+               ret = LTTNG_ERR_NO_EVENT;
+       } else {
+               ret = error ? LTTNG_ERR_KERN_DISABLE_FAIL : LTTNG_OK;
+       }
+
+       return ret;
 }
 
 /*
@@ -142,23 +119,11 @@ int event_kernel_enable_event(struct ltt_kernel_channel *kchan,
        kevent = trace_kernel_find_event(event->name, kchan,
                        event->type, filter);
        if (kevent == NULL) {
-               ret = kernel_create_event(event, kchan,
-                       filter_expression, filter);
+               ret = kernel_create_event(event, kchan, filter_expression, filter);
                /* We have passed ownership */
                filter_expression = NULL;
                filter = NULL;
-               if (ret < 0) {
-                       switch (-ret) {
-                       case EEXIST:
-                               ret = LTTNG_ERR_KERN_EVENT_EXIST;
-                               break;
-                       case ENOSYS:
-                               ret = LTTNG_ERR_KERN_EVENT_ENOSYS;
-                               break;
-                       default:
-                               ret = LTTNG_ERR_KERN_ENABLE_FAIL;
-                               break;
-                       }
+               if (ret) {
                        goto end;
                }
        } else if (kevent->enabled == 0) {
@@ -186,103 +151,6 @@ end:
  * ============================
  */
 
-/*
- * Enable all UST tracepoints for a channel from a UST session.
- */
-int event_ust_enable_all_tracepoints(struct ltt_ust_session *usess,
-               struct ltt_ust_channel *uchan,
-               char *filter_expression,
-               struct lttng_filter_bytecode *filter)
-{
-       int ret, i, size;
-       struct lttng_ht_iter iter;
-       struct ltt_ust_event *uevent = NULL;
-       struct lttng_event *events = NULL;
-
-       assert(usess);
-       assert(uchan);
-
-       rcu_read_lock();
-
-       /* Enable existing events */
-       cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent,
-                       node.node) {
-               if (uevent->enabled == 0) {
-                       ret = ust_app_enable_event_glb(usess, uchan, uevent);
-                       if (ret < 0) {
-                               continue;
-                       }
-                       uevent->enabled = 1;
-               }
-       }
-
-       /* Get all UST available events */
-       size = ust_app_list_events(&events);
-       if (size < 0) {
-               ret = LTTNG_ERR_UST_LIST_FAIL;
-               goto error;
-       }
-
-       for (i = 0; i < size; i++) {
-               /*
-                * Check if event exist and if so, continue since it was enable
-                * previously.
-                */
-               uevent = trace_ust_find_event(uchan->events, events[i].name, filter,
-                               events[i].loglevel, NULL);
-               if (uevent != NULL) {
-                       ret = ust_app_enable_event_pid(usess, uchan, uevent,
-                                       events[i].pid);
-                       if (ret < 0) {
-                               if (ret != -LTTNG_UST_ERR_EXIST) {
-                                       ret = LTTNG_ERR_UST_ENABLE_FAIL;
-                                       goto error;
-                               }
-                       }
-                       continue;
-               }
-
-               /* Create ust event */
-               uevent = trace_ust_create_event(&events[i], filter_expression,
-                       filter, NULL);
-               if (uevent == NULL) {
-                       ret = LTTNG_ERR_FATAL;
-                       goto error_destroy;
-               }
-
-               /* Create event for the specific PID */
-               ret = ust_app_enable_event_pid(usess, uchan, uevent,
-                               events[i].pid);
-               if (ret < 0) {
-                       if (ret == -LTTNG_UST_ERR_EXIST) {
-                               ret = LTTNG_ERR_UST_EVENT_EXIST;
-                               goto error;
-                       } else {
-                               ret = LTTNG_ERR_UST_ENABLE_FAIL;
-                               goto error_destroy;
-                       }
-               }
-
-               uevent->enabled = 1;
-               /* Add ltt ust event to channel */
-               rcu_read_lock();
-               add_unique_ust_event(uchan->events, uevent);
-               rcu_read_unlock();
-       }
-       free(events);
-
-       rcu_read_unlock();
-       return LTTNG_OK;
-
-error_destroy:
-       trace_ust_destroy_event(uevent);
-
-error:
-       free(events);
-       rcu_read_unlock();
-       return ret;
-}
-
 /*
  * Enable UST tracepoint event for a channel from a UST session.
  * We own filter_expression, filter, and exclusion.
@@ -291,7 +159,8 @@ int event_ust_enable_tracepoint(struct ltt_ust_session *usess,
                struct ltt_ust_channel *uchan, struct lttng_event *event,
                char *filter_expression,
                struct lttng_filter_bytecode *filter,
-               struct lttng_event_exclusion *exclusion)
+               struct lttng_event_exclusion *exclusion,
+               bool internal_event)
 {
        int ret = LTTNG_OK, to_create = 0;
        struct ltt_ust_event *uevent;
@@ -303,16 +172,15 @@ int event_ust_enable_tracepoint(struct ltt_ust_session *usess,
        rcu_read_lock();
 
        uevent = trace_ust_find_event(uchan->events, event->name, filter,
-                       event->loglevel, exclusion);
-       if (uevent == NULL) {
-               uevent = trace_ust_create_event(event, filter_expression,
-                       filter, exclusion);
+                       event->loglevel_type, event->loglevel, exclusion);
+       if (!uevent) {
+               ret = trace_ust_create_event(event, filter_expression,
+                               filter, exclusion, internal_event, &uevent);
                /* We have passed ownership */
                filter_expression = NULL;
                filter = NULL;
                exclusion = NULL;
-               if (uevent == NULL) {
-                       ret = LTTNG_ERR_UST_ENABLE_FAIL;
+               if (ret != LTTNG_OK) {
                        goto error;
                }
 
@@ -327,6 +195,14 @@ int event_ust_enable_tracepoint(struct ltt_ust_session *usess,
        }
 
        uevent->enabled = 1;
+       if (to_create) {
+               /* Add ltt ust event to channel */
+               add_unique_ust_event(uchan->events, uevent);
+       }
+
+       if (!usess->active) {
+               goto end;
+       }
 
        if (to_create) {
                /* Create event on all UST registered apps for session */
@@ -346,11 +222,6 @@ int event_ust_enable_tracepoint(struct ltt_ust_session *usess,
                }
        }
 
-       if (to_create) {
-               /* Add ltt ust event to channel */
-               add_unique_ust_event(uchan->events, uevent);
-       }
-
        DBG("Event UST %s %s in channel %s", uevent->attr.name,
                        to_create ? "created" : "enabled", uchan->name);
 
@@ -423,17 +294,18 @@ int event_ust_disable_tracepoint(struct ltt_ust_session *usess,
                        /* It's already disabled so everything is OK */
                        goto next;
                }
+               uevent->enabled = 0;
+               DBG2("Event UST %s disabled in channel %s", uevent->attr.name,
+                               uchan->name);
 
+               if (!usess->active) {
+                       goto next;
+               }
                ret = ust_app_disable_event_glb(usess, uchan, uevent);
                if (ret < 0 && ret != -LTTNG_UST_ERR_EXIST) {
                        ret = LTTNG_ERR_UST_DISABLE_FAIL;
                        goto error;
                }
-               uevent->enabled = 0;
-
-               DBG2("Event UST %s disabled in channel %s", uevent->attr.name,
-                               uchan->name);
-
 next:
                /* Get next duplicate event by name. */
                cds_lfht_next_duplicate(ht->ht, trace_ust_ht_match_event_by_name,
@@ -454,7 +326,7 @@ error:
 int event_ust_disable_all_tracepoints(struct ltt_ust_session *usess,
                struct ltt_ust_channel *uchan)
 {
-       int ret, i, size;
+       int ret, i, size, error = 0;
        struct lttng_ht_iter iter;
        struct ltt_ust_event *uevent = NULL;
        struct lttng_event *events = NULL;
@@ -471,6 +343,7 @@ int event_ust_disable_all_tracepoints(struct ltt_ust_session *usess,
                        ret = event_ust_disable_tracepoint(usess, uchan,
                                        uevent->attr.name);
                        if (ret < 0) {
+                               error = LTTNG_ERR_UST_DISABLE_FAIL;
                                continue;
                        }
                }
@@ -486,19 +359,17 @@ int event_ust_disable_all_tracepoints(struct ltt_ust_session *usess,
        for (i = 0; i < size; i++) {
                ret = event_ust_disable_tracepoint(usess, uchan,
                                events[i].name);
-               if (ret != LTTNG_OK) {
+               if (ret < 0) {
                        /* Continue to disable the rest... */
+                       error = LTTNG_ERR_UST_DISABLE_FAIL;
                        continue;
                }
        }
-       free(events);
-
-       rcu_read_unlock();
-       return LTTNG_OK;
 
+       ret = error ? error : LTTNG_OK;
 error:
-       free(events);
        rcu_read_unlock();
+       free(events);
        return ret;
 }
 
@@ -509,7 +380,7 @@ error:
  */
 int event_agent_enable_all(struct ltt_ust_session *usess,
                struct agent *agt, struct lttng_event *event,
-               struct lttng_filter_bytecode *filter)
+               struct lttng_filter_bytecode *filter ,char *filter_expression)
 {
        int ret;
        struct agent_event *aevent;
@@ -520,7 +391,7 @@ int event_agent_enable_all(struct ltt_ust_session *usess,
        DBG("Event agent enabling ALL events for session %" PRIu64, usess->id);
 
        /* Enable event on agent application through TCP socket. */
-       ret = event_agent_enable(usess, agt, event, filter);
+       ret = event_agent_enable(usess, agt, event, filter, filter_expression);
        if (ret != LTTNG_OK) {
                goto error;
        }
@@ -539,6 +410,70 @@ error:
        return ret;
 }
 
+/*
+ * Check if this event's filter requires the activation of application contexts
+ * and enable them in the agent.
+ * TODO: bytecode iterator does not support non-legacy application
+ * contexts yet. Not an issue for now, since they are not generated by
+ * the lttng-ctl library.
+ */
+static int add_filter_app_ctx(struct lttng_filter_bytecode *bytecode,
+               const char *filter_expression, struct agent *agt)
+{
+       int ret = LTTNG_OK;
+       char *provider_name = NULL, *ctx_name = NULL;
+       struct bytecode_symbol_iterator *it =
+                       bytecode_symbol_iterator_create(bytecode);
+
+       if (!it) {
+               ret = LTTNG_ERR_NOMEM;
+               goto end;
+       }
+
+       do {
+               struct lttng_event_context ctx;
+               const char *symbol_name =
+                               bytecode_symbol_iterator_get_name(it);
+
+               if (parse_application_context(symbol_name, &provider_name,
+                               &ctx_name)) {
+                       /* Not an application context. */
+                       continue;
+               }
+
+               ctx.ctx = LTTNG_EVENT_CONTEXT_APP_CONTEXT;
+               ctx.u.app_ctx.provider_name = provider_name;
+               ctx.u.app_ctx.ctx_name = ctx_name;
+
+               /* Recognized an application context. */
+               DBG("Enabling event with filter expression \"%s\" requires enabling the %s:%s application context.",
+                               filter_expression, provider_name, ctx_name);
+
+               ret = agent_add_context(&ctx, agt);
+               if (ret != LTTNG_OK) {
+                       ERR("Failed to add application context %s:%s.",
+                                       provider_name, ctx_name);
+                       goto end;
+               }
+
+               ret = agent_enable_context(&ctx, agt->domain);
+               if (ret != LTTNG_OK) {
+                       ERR("Failed to enable application context %s:%s.",
+                                       provider_name, ctx_name);
+                       goto end;
+               }
+
+               free(provider_name);
+               free(ctx_name);
+               provider_name = ctx_name = NULL;
+       } while (bytecode_symbol_iterator_next(it) == 0);
+end:
+       free(provider_name);
+       free(ctx_name);
+       bytecode_symbol_iterator_destroy(it);
+       return ret;
+}
+
 /*
  * Enable a single agent event for a given UST session.
  *
@@ -546,7 +481,8 @@ error:
  */
 int event_agent_enable(struct ltt_ust_session *usess,
                struct agent *agt, struct lttng_event *event,
-               struct lttng_filter_bytecode *filter)
+               struct lttng_filter_bytecode *filter,
+               char *filter_expression)
 {
        int ret, created = 0;
        struct agent_event *aevent;
@@ -556,23 +492,35 @@ int event_agent_enable(struct ltt_ust_session *usess,
        assert(agt);
 
        DBG("Event agent enabling %s for session %" PRIu64 " with loglevel type %d "
-                       "and loglevel %d", event->name, usess->id, event->loglevel_type,
-                       event->loglevel);
+                       ", loglevel %d and filter \"%s\"", event->name,
+                       usess->id, event->loglevel_type, event->loglevel,
+                       filter_expression ? filter_expression : "NULL");
 
-       aevent = agent_find_event(event->name, event->loglevel, agt);
+       aevent = agent_find_event(event->name, event->loglevel_type,
+                       event->loglevel, filter_expression, agt);
        if (!aevent) {
-               aevent = agent_create_event(event->name, filter);
+               aevent = agent_create_event(event->name, event->loglevel_type,
+                               event->loglevel, filter,
+                               filter_expression);
                if (!aevent) {
                        ret = LTTNG_ERR_NOMEM;
                        goto error;
                }
-               aevent->loglevel = event->loglevel;
-               aevent->loglevel_type = event->loglevel_type;
+               filter = NULL;
+               filter_expression = NULL;
                created = 1;
        }
 
+       if (created && filter) {
+               ret = add_filter_app_ctx(filter, filter_expression, agt);
+               if (ret != LTTNG_OK) {
+                       goto error;
+               }
+       }
+
        /* Already enabled? */
        if (aevent->enabled) {
+               ret = LTTNG_OK;
                goto end;
        }
 
@@ -586,13 +534,16 @@ int event_agent_enable(struct ltt_ust_session *usess,
                agent_add_event(aevent, agt);
        }
 
-end:
-       return LTTNG_OK;
+       ret = LTTNG_OK;
+       goto end;
 
 error:
        if (created) {
                agent_destroy_event(aevent);
        }
+end:
+       free(filter);
+       free(filter_expression);
        return ret;
 }
 
@@ -612,7 +563,7 @@ const char *event_get_default_agent_ust_name(enum lttng_domain_type domain)
                default_event_name = DEFAULT_JUL_EVENT_NAME;
                break;
        case LTTNG_DOMAIN_PYTHON:
-               default_event_name = DEFAULT_USER_PYTHON_EVENT_NAME;
+               default_event_name = DEFAULT_PYTHON_EVENT_NAME;
                break;
        default:
                assert(0);
@@ -622,30 +573,26 @@ const char *event_get_default_agent_ust_name(enum lttng_domain_type domain)
 }
 
 /*
- * Disable a single agent event for a given UST session.
+ * Disable a given agent event for a given UST session.
  *
+ * Must be called with the RCU read lock held.
  * Return LTTNG_OK on success or else a LTTNG_ERR* code.
  */
-int event_agent_disable(struct ltt_ust_session *usess, struct agent *agt,
-               char *event_name)
+static int event_agent_disable_one(struct ltt_ust_session *usess,
+               struct agent *agt, struct agent_event *aevent)
 {
        int ret;
-       struct agent_event *aevent;
        struct ltt_ust_event *uevent = NULL;
        struct ltt_ust_channel *uchan = NULL;
        const char *ust_event_name, *ust_channel_name;
 
        assert(agt);
        assert(usess);
-       assert(event_name);
+       assert(aevent);
 
-       DBG("Event agent disabling %s for session %" PRIu64, event_name, usess->id);
-
-       aevent = agent_find_event_by_name(event_name, agt);
-       if (!aevent) {
-               ret = LTTNG_ERR_UST_EVENT_NOT_FOUND;
-               goto error;
-       }
+       DBG("Event agent disabling %s (loglevel type %d, loglevel value %d) for session %" PRIu64,
+               aevent->name, aevent->loglevel_type, aevent->loglevel_value,
+               usess->id);
 
        /* Already disabled? */
        if (!aevent->enabled) {
@@ -681,19 +628,22 @@ int event_agent_disable(struct ltt_ust_session *usess, struct agent *agt,
        }
 
        /*
-        * The loglevel is hardcoded with 0 here since the agent ust event is set
-        * with the loglevel type to ALL thus the loglevel stays 0. The event's
-        * filter is the one handling the loglevel for agent.
+        * Agent UST event has its loglevel type forced to
+        * LTTNG_UST_LOGLEVEL_ALL. The actual loglevel type/value filtering
+        * happens thanks to an UST filter. The following -1 is actually
+        * ignored since the type is LTTNG_UST_LOGLEVEL_ALL.
         */
        uevent = trace_ust_find_event(uchan->events, (char *) ust_event_name,
-                       aevent->filter, 0, NULL);
+                       aevent->filter, LTTNG_UST_LOGLEVEL_ALL, -1, NULL);
        /* If the agent event exists, it must be available on the UST side. */
        assert(uevent);
 
-       ret = ust_app_disable_event_glb(usess, uchan, uevent);
-       if (ret < 0 && ret != -LTTNG_UST_ERR_EXIST) {
-               ret = LTTNG_ERR_UST_DISABLE_FAIL;
-               goto error;
+       if (usess->active) {
+               ret = ust_app_disable_event_glb(usess, uchan, uevent);
+               if (ret < 0 && ret != -LTTNG_UST_ERR_EXIST) {
+                       ret = LTTNG_ERR_UST_DISABLE_FAIL;
+                       goto error;
+               }
        }
 
        /*
@@ -713,6 +663,52 @@ end:
 error:
        return ret;
 }
+
+/*
+ * Disable all agent events matching a given name for a given UST session.
+ *
+ * Return LTTNG_OK on success or else a LTTNG_ERR* code.
+ */
+int event_agent_disable(struct ltt_ust_session *usess, struct agent *agt,
+               char *event_name)
+{
+       int ret = LTTNG_OK;
+       struct agent_event *aevent;
+       struct lttng_ht_iter iter;
+       struct lttng_ht_node_str *node;
+
+       assert(agt);
+       assert(usess);
+       assert(event_name);
+
+       DBG("Event agent disabling %s (all loglevels) for session %" PRIu64, event_name, usess->id);
+
+       rcu_read_lock();
+       agent_find_events_by_name(event_name, agt, &iter);
+       node = lttng_ht_iter_get_node_str(&iter);
+
+       if (node == NULL) {
+               DBG2("Event agent NOT found by name %s", event_name);
+               ret = LTTNG_ERR_UST_EVENT_NOT_FOUND;
+               goto end;
+       }
+
+       do {
+               aevent = caa_container_of(node, struct agent_event, node);
+               ret = event_agent_disable_one(usess, agt, aevent);
+
+               if (ret != LTTNG_OK) {
+                       goto end;
+               }
+
+               /* Get next duplicate agent event by name. */
+               agent_event_next_duplicate(event_name, agt, &iter);
+               node = lttng_ht_iter_get_node_str(&iter);
+       } while (node);
+end:
+       rcu_read_unlock();
+       return ret;
+}
 /*
  * Disable all agent event for a given UST session.
  *
@@ -737,7 +733,7 @@ int event_agent_disable_all(struct ltt_ust_session *usess,
                goto error;
        }
 
-       /* Flag every event that they are now enabled. */
+       /* Disable every event. */
        rcu_read_lock();
        cds_lfht_for_each_entry(agt->events->ht, &iter.iter, aevent,
                        node.node) {
@@ -747,14 +743,13 @@ int event_agent_disable_all(struct ltt_ust_session *usess,
 
                ret = event_agent_disable(usess, agt, aevent->name);
                if (ret != LTTNG_OK) {
-                       rcu_read_unlock();
-                       goto error;
+                       goto error_unlock;
                }
        }
-       rcu_read_unlock();
-
        ret = LTTNG_OK;
 
+error_unlock:
+       rcu_read_unlock();
 error:
        return ret;
 }
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