X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fust-app.c;h=e457cae6803f2ef43491a580ab0f6501171c7494;hb=1950109e7a08d8064ef5b1f446524274b4fa72d5;hp=9250433ab1573b4d3534caf677e0bf817fe0c658;hpb=7972aab22f74b18faa168c0482216a3dd711a075;p=lttng-tools.git diff --git a/src/bin/lttng-sessiond/ust-app.c b/src/bin/lttng-sessiond/ust-app.c index 9250433ab..e457cae68 100644 --- a/src/bin/lttng-sessiond/ust-app.c +++ b/src/bin/lttng-sessiond/ust-app.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include @@ -37,6 +38,7 @@ #include "ust-app.h" #include "ust-consumer.h" #include "ust-ctl.h" +#include "utils.h" /* Next available channel key. */ static unsigned long next_channel_key; @@ -58,6 +60,19 @@ static inline unsigned long get_next_session_id(void) return uatomic_add_return(&next_session_id, 1); } +static void copy_channel_attr_to_ustctl( + struct ustctl_consumer_channel_attr *attr, + struct lttng_ust_channel_attr *uattr) +{ + /* Copy event attributes since the layout is different. */ + attr->subbuf_size = uattr->subbuf_size; + attr->num_subbuf = uattr->num_subbuf; + attr->overwrite = uattr->overwrite; + attr->switch_timer_interval = uattr->switch_timer_interval; + attr->read_timer_interval = uattr->read_timer_interval; + attr->output = uattr->output; +} + /* * Match function for the hash table lookup. * @@ -291,6 +306,23 @@ void delete_ust_app_stream(int sock, struct ust_app_stream *stream) free(stream); } +/* + * We need to execute ht_destroy outside of RCU read-side critical + * section and outside of call_rcu thread, so we postpone its execution + * using ht_cleanup_push. It is simpler than to change the semantic of + * the many callers of delete_ust_app_session(). + */ +static +void delete_ust_app_channel_rcu(struct rcu_head *head) +{ + struct ust_app_channel *ua_chan = + caa_container_of(head, struct ust_app_channel, rcu_head); + + ht_cleanup_push(ua_chan->ctx); + ht_cleanup_push(ua_chan->events); + free(ua_chan); +} + /* * Delete ust app channel safely. RCU read lock must be held before calling * this function. @@ -322,7 +354,6 @@ void delete_ust_app_channel(int sock, struct ust_app_channel *ua_chan, assert(!ret); delete_ust_app_ctx(sock, ua_ctx); } - lttng_ht_destroy(ua_chan->ctx); /* Wipe events */ cds_lfht_for_each_entry(ua_chan->events->ht, &iter.iter, ua_event, @@ -331,7 +362,6 @@ void delete_ust_app_channel(int sock, struct ust_app_channel *ua_chan, assert(!ret); delete_ust_app_event(sock, ua_event); } - lttng_ht_destroy(ua_chan->events); /* Wipe and free registry from session registry. */ registry = get_session_registry(ua_chan->session); @@ -351,21 +381,101 @@ void delete_ust_app_channel(int sock, struct ust_app_channel *ua_chan, lttng_fd_put(LTTNG_FD_APPS, 1); free(ua_chan->obj); } - free(ua_chan); + call_rcu(&ua_chan->rcu_head, delete_ust_app_channel_rcu); +} + +/* + * Push metadata to consumer socket. + * + * The socket lock MUST be acquired. + * The ust app session lock MUST be acquired. + * + * On success, return the len of metadata pushed or else a negative value. + */ +ssize_t ust_app_push_metadata(struct ust_registry_session *registry, + struct consumer_socket *socket, int send_zero_data) +{ + int ret; + char *metadata_str = NULL; + size_t len, offset; + ssize_t ret_val; + + assert(registry); + assert(socket); + + /* + * On a push metadata error either the consumer is dead or the metadata + * channel has been destroyed because its endpoint might have died (e.g: + * relayd). If so, the metadata closed flag is set to 1 so we deny pushing + * metadata again which is not valid anymore on the consumer side. + * + * The ust app session mutex locked allows us to make this check without + * the registry lock. + */ + if (registry->metadata_closed) { + return -EPIPE; + } + + pthread_mutex_lock(®istry->lock); + + offset = registry->metadata_len_sent; + len = registry->metadata_len - registry->metadata_len_sent; + if (len == 0) { + DBG3("No metadata to push for metadata key %" PRIu64, + registry->metadata_key); + ret_val = len; + if (send_zero_data) { + DBG("No metadata to push"); + goto push_data; + } + goto end; + } + + /* Allocate only what we have to send. */ + metadata_str = zmalloc(len); + if (!metadata_str) { + PERROR("zmalloc ust app metadata string"); + ret_val = -ENOMEM; + goto error; + } + /* Copy what we haven't send out. */ + memcpy(metadata_str, registry->metadata + offset, len); + registry->metadata_len_sent += len; + +push_data: + pthread_mutex_unlock(®istry->lock); + ret = consumer_push_metadata(socket, registry->metadata_key, + metadata_str, len, offset); + if (ret < 0) { + ret_val = ret; + goto error_push; + } + + free(metadata_str); + return len; + +end: +error: + pthread_mutex_unlock(®istry->lock); +error_push: + free(metadata_str); + return ret_val; } /* * For a given application and session, push metadata to consumer. The session * lock MUST be acquired here before calling this. + * Either sock or consumer is required : if sock is NULL, the default + * socket to send the metadata is retrieved from consumer, if sock + * is not NULL we use it to send the metadata. * * Return 0 on success else a negative error. */ static int push_metadata(struct ust_registry_session *registry, struct consumer_output *consumer) { - int ret; - char *metadata_str = NULL; - size_t len, offset; + int ret_val; + ssize_t ret; struct consumer_socket *socket; assert(registry); @@ -378,15 +488,15 @@ static int push_metadata(struct ust_registry_session *registry, * no start has been done previously. */ if (!registry->metadata_key) { - ret = 0; - goto error_rcu_unlock; + ret_val = 0; + goto end_rcu_unlock; } /* Get consumer socket to use to push the metadata.*/ socket = consumer_find_socket_by_bitness(registry->bits_per_long, consumer); if (!socket) { - ret = -1; + ret_val = -1; goto error_rcu_unlock; } @@ -401,54 +511,26 @@ static int push_metadata(struct ust_registry_session *registry, * ability to reorder the metadata it receives. */ pthread_mutex_lock(socket->lock); - pthread_mutex_lock(®istry->lock); - - offset = registry->metadata_len_sent; - len = registry->metadata_len - registry->metadata_len_sent; - if (len == 0) { - DBG3("No metadata to push for metadata key %" PRIu64, - registry->metadata_key); - ret = 0; - goto error_reg_unlock; - } - assert(len > 0); - - /* Allocate only what we have to send. */ - metadata_str = zmalloc(len); - if (!metadata_str) { - PERROR("zmalloc ust app metadata string"); - ret = -ENOMEM; - goto error_reg_unlock; - } - /* Copy what we haven't send out. */ - memcpy(metadata_str, registry->metadata + offset, len); - - pthread_mutex_unlock(®istry->lock); - - ret = consumer_push_metadata(socket, registry->metadata_key, - metadata_str, len, offset); + ret = ust_app_push_metadata(registry, socket, 0); + pthread_mutex_unlock(socket->lock); if (ret < 0) { - pthread_mutex_unlock(socket->lock); + ret_val = ret; goto error_rcu_unlock; } - /* Update len sent of the registry. */ - pthread_mutex_lock(®istry->lock); - registry->metadata_len_sent += len; - pthread_mutex_unlock(®istry->lock); - pthread_mutex_unlock(socket->lock); - rcu_read_unlock(); - free(metadata_str); return 0; -error_reg_unlock: - pthread_mutex_unlock(®istry->lock); - pthread_mutex_unlock(socket->lock); error_rcu_unlock: + /* + * On error, flag the registry that the metadata is closed. We were unable + * to push anything and this means that either the consumer is not + * responding or the metadata cache has been destroyed on the consumer. + */ + registry->metadata_closed = 1; +end_rcu_unlock: rcu_read_unlock(); - free(metadata_str); - return ret; + return ret_val; } /* @@ -472,7 +554,7 @@ static int close_metadata(struct ust_registry_session *registry, if (!registry->metadata_key || registry->metadata_closed) { ret = 0; - goto error; + goto end; } /* Get consumer socket to use to push the metadata.*/ @@ -488,14 +570,34 @@ static int close_metadata(struct ust_registry_session *registry, goto error; } - /* Metadata successfully closed. Flag the registry. */ - registry->metadata_closed = 1; - error: + /* + * Metadata closed. Even on error this means that the consumer is not + * responding or not found so either way a second close should NOT be emit + * for this registry. + */ + registry->metadata_closed = 1; +end: rcu_read_unlock(); return ret; } +/* + * We need to execute ht_destroy outside of RCU read-side critical + * section and outside of call_rcu thread, so we postpone its execution + * using ht_cleanup_push. It is simpler than to change the semantic of + * the many callers of delete_ust_app_session(). + */ +static +void delete_ust_app_session_rcu(struct rcu_head *head) +{ + struct ust_app_session *ua_sess = + caa_container_of(head, struct ust_app_session, rcu_head); + + ht_cleanup_push(ua_sess->channels); + free(ua_sess); +} + /* * Delete ust app session safely. RCU read lock must be held before calling * this function. @@ -511,16 +613,21 @@ void delete_ust_app_session(int sock, struct ust_app_session *ua_sess, assert(ua_sess); + pthread_mutex_lock(&ua_sess->lock); + registry = get_session_registry(ua_sess); - if (registry) { + if (registry && !registry->metadata_closed) { /* Push metadata for application before freeing the application. */ (void) push_metadata(registry, ua_sess->consumer); /* * Don't ask to close metadata for global per UID buffers. Close - * metadata only on destroy trace session in this case. + * metadata only on destroy trace session in this case. Also, the + * previous push metadata could have flag the metadata registry to + * close so don't send a close command if closed. */ - if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID) { + if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID && + !registry->metadata_closed) { /* And ask to close it for this session registry. */ (void) close_metadata(registry, ua_sess->consumer); } @@ -532,7 +639,6 @@ void delete_ust_app_session(int sock, struct ust_app_session *ua_sess, assert(!ret); delete_ust_app_channel(sock, ua_chan, app); } - lttng_ht_destroy(ua_sess->channels); /* In case of per PID, the registry is kept in the session. */ if (ua_sess->buffer_type == LTTNG_BUFFER_PER_PID) { @@ -550,12 +656,16 @@ void delete_ust_app_session(int sock, struct ust_app_session *ua_sess, sock, ret); } } - free(ua_sess); + pthread_mutex_unlock(&ua_sess->lock); + + call_rcu(&ua_sess->rcu_head, delete_ust_app_session_rcu); } /* * Delete a traceable application structure from the global list. Never call * this function outside of a call_rcu call. + * + * RCU read side lock should _NOT_ be held when calling this function. */ static void delete_ust_app(struct ust_app *app) @@ -563,21 +673,21 @@ void delete_ust_app(struct ust_app *app) int ret, sock; struct ust_app_session *ua_sess, *tmp_ua_sess; - rcu_read_lock(); - /* Delete ust app sessions info */ sock = app->sock; app->sock = -1; - lttng_ht_destroy(app->sessions); - /* Wipe sessions */ cds_list_for_each_entry_safe(ua_sess, tmp_ua_sess, &app->teardown_head, teardown_node) { /* Free every object in the session and the session. */ + rcu_read_lock(); delete_ust_app_session(sock, ua_sess, app); + rcu_read_unlock(); } - lttng_ht_destroy(app->ust_objd); + + ht_cleanup_push(app->sessions); + ht_cleanup_push(app->ust_objd); /* * Wait until we have deleted the application from the sock hash table @@ -600,8 +710,6 @@ void delete_ust_app(struct ust_app *app) DBG2("UST app pid %d deleted", app->pid); free(app); - - rcu_read_unlock(); } /* @@ -1253,6 +1361,9 @@ static void shadow_copy_channel(struct ust_app_channel *ua_chan, strncpy(ua_chan->name, uchan->name, sizeof(ua_chan->name)); ua_chan->name[sizeof(ua_chan->name) - 1] = '\0'; + ua_chan->tracefile_size = uchan->tracefile_size; + ua_chan->tracefile_count = uchan->tracefile_count; + /* Copy event attributes since the layout is different. */ ua_chan->attr.subbuf_size = uchan->attr.subbuf_size; ua_chan->attr.num_subbuf = uchan->attr.num_subbuf; @@ -1329,11 +1440,12 @@ static void shadow_copy_session(struct ust_app_session *ua_sess, ua_sess->bits_per_long = app->bits_per_long; /* There is only one consumer object per session possible. */ ua_sess->consumer = usess->consumer; + ua_sess->output_traces = usess->output_traces; switch (ua_sess->buffer_type) { case LTTNG_BUFFER_PER_PID: ret = snprintf(ua_sess->path, sizeof(ua_sess->path), - DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s/", app->name, app->pid, + DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s", app->name, app->pid, datetime); break; case LTTNG_BUFFER_PER_UID: @@ -1454,7 +1566,9 @@ static int setup_buffer_reg_pid(struct ust_app_session *ua_sess, ret = ust_registry_session_init(®_pid->registry->reg.ust, app, app->bits_per_long, app->uint8_t_alignment, app->uint16_t_alignment, app->uint32_t_alignment, - app->uint64_t_alignment, app->long_alignment, app->byte_order); + app->uint64_t_alignment, app->long_alignment, + app->byte_order, app->version.major, + app->version.minor); if (ret < 0) { goto error; } @@ -1505,10 +1619,12 @@ static int setup_buffer_reg_uid(struct ltt_ust_session *usess, } /* Initialize registry. */ - ret = ust_registry_session_init(®_uid->registry->reg.ust, app, + ret = ust_registry_session_init(®_uid->registry->reg.ust, NULL, app->bits_per_long, app->uint8_t_alignment, app->uint16_t_alignment, app->uint32_t_alignment, - app->uint64_t_alignment, app->long_alignment, app->byte_order); + app->uint64_t_alignment, app->long_alignment, + app->byte_order, app->version.major, + app->version.minor); if (ret < 0) { goto error; } @@ -1831,9 +1947,11 @@ static int do_consumer_create_channel(struct ltt_ust_session *usess, * Now get the channel from the consumer. This call wil populate the stream * list of that channel and set the ust objects. */ - ret = ust_consumer_get_channel(socket, ua_chan); - if (ret < 0) { - goto error_destroy; + if (usess->consumer->enabled) { + ret = ust_consumer_get_channel(socket, ua_chan); + if (ret < 0) { + goto error_destroy; + } } rcu_read_unlock(); @@ -2101,6 +2219,7 @@ static int send_channel_uid_to_ust(struct buffer_reg_channel *reg_chan, ret = ust_consumer_send_stream_to_ust(app, ua_chan, &stream); if (ret < 0) { + (void) release_ust_app_stream(-1, &stream); goto error_stream_unlock; } @@ -2163,6 +2282,14 @@ static int create_channel_per_uid(struct ust_app *app, ret = do_consumer_create_channel(usess, ua_sess, ua_chan, app->bits_per_long, reg_uid->registry->reg.ust); if (ret < 0) { + /* + * Let's remove the previously created buffer registry channel so + * it's not visible anymore in the session registry. + */ + ust_registry_channel_del_free(reg_uid->registry->reg.ust, + ua_chan->tracing_channel_id); + buffer_reg_channel_remove(reg_uid->registry, reg_chan); + buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST); goto error; } @@ -2295,7 +2422,7 @@ error: * Create UST app channel and create it on the tracer. Set ua_chanp of the * newly created channel if not NULL. * - * Called with UST app session lock held. + * Called with UST app session lock and RCU read-side lock held. * * Return 0 on success or else a negative value. */ @@ -2321,7 +2448,7 @@ static int create_ust_app_channel(struct ust_app_session *ua_sess, if (ua_chan == NULL) { /* Only malloc can fail here */ ret = -ENOMEM; - goto error; + goto error_alloc; } shadow_copy_channel(ua_chan, uchan); @@ -2349,6 +2476,7 @@ end: error: delete_ust_app_channel(ua_chan->is_sent ? app->sock : -1, ua_chan, app); +error_alloc: return ret; } @@ -2410,7 +2538,8 @@ error: * Called with UST app session lock held and RCU read side lock. */ static int create_ust_app_metadata(struct ust_app_session *ua_sess, - struct ust_app *app, struct consumer_output *consumer) + struct ust_app *app, struct consumer_output *consumer, + struct ustctl_consumer_channel_attr *attr) { int ret = 0; struct ust_app_channel *metadata; @@ -2424,8 +2553,8 @@ static int create_ust_app_metadata(struct ust_app_session *ua_sess, registry = get_session_registry(ua_sess); assert(registry); - /* Metadata already exists for this registry. */ - if (registry->metadata_key) { + /* Metadata already exists for this registry or it was closed previously */ + if (registry->metadata_key || registry->metadata_closed) { ret = 0; goto error; } @@ -2438,20 +2567,19 @@ static int create_ust_app_metadata(struct ust_app_session *ua_sess, goto error; } - /* Set default attributes for metadata. */ - metadata->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE; - metadata->attr.subbuf_size = default_get_metadata_subbuf_size(); - metadata->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM; - metadata->attr.switch_timer_interval = DEFAULT_UST_CHANNEL_SWITCH_TIMER; - metadata->attr.read_timer_interval = DEFAULT_UST_CHANNEL_READ_TIMER; - metadata->attr.output = LTTNG_UST_MMAP; - metadata->attr.type = LTTNG_UST_CHAN_METADATA; - - /* Get the right consumer socket for the application. */ - socket = consumer_find_socket_by_bitness(app->bits_per_long, consumer); - if (!socket) { - ret = -EINVAL; - goto error_consumer; + if (!attr) { + /* Set default attributes for metadata. */ + metadata->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE; + metadata->attr.subbuf_size = default_get_metadata_subbuf_size(); + metadata->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM; + metadata->attr.switch_timer_interval = DEFAULT_METADATA_SWITCH_TIMER; + metadata->attr.read_timer_interval = DEFAULT_METADATA_READ_TIMER; + metadata->attr.output = LTTNG_UST_MMAP; + metadata->attr.type = LTTNG_UST_CHAN_METADATA; + } else { + memcpy(&metadata->attr, attr, sizeof(metadata->attr)); + metadata->attr.output = LTTNG_UST_MMAP; + metadata->attr.type = LTTNG_UST_CHAN_METADATA; } /* Need one fd for the channel. */ @@ -2461,6 +2589,21 @@ static int create_ust_app_metadata(struct ust_app_session *ua_sess, goto error; } + /* Get the right consumer socket for the application. */ + socket = consumer_find_socket_by_bitness(app->bits_per_long, consumer); + if (!socket) { + ret = -EINVAL; + goto error_consumer; + } + + /* + * Keep metadata key so we can identify it on the consumer side. Assign it + * to the registry *before* we ask the consumer so we avoid the race of the + * consumer requesting the metadata and the ask_channel call on our side + * did not returned yet. + */ + registry->metadata_key = metadata->key; + /* * Ask the metadata channel creation to the consumer. The metadata object * will be created by the consumer and kept their. However, the stream is @@ -2470,11 +2613,8 @@ static int create_ust_app_metadata(struct ust_app_session *ua_sess, ret = ust_consumer_ask_channel(ua_sess, metadata, consumer, socket, registry); if (ret < 0) { - /* - * Safe because the metadata obj pointer is not set so the delete below - * will not put a FD back again. - */ - lttng_fd_put(LTTNG_FD_APPS, 1); + /* Nullify the metadata key so we don't try to close it later on. */ + registry->metadata_key = 0; goto error_consumer; } @@ -2486,21 +2626,16 @@ static int create_ust_app_metadata(struct ust_app_session *ua_sess, */ ret = consumer_setup_metadata(socket, metadata->key); if (ret < 0) { - /* - * Safe because the metadata obj pointer is not set so the delete below - * will not put a FD back again. - */ - lttng_fd_put(LTTNG_FD_APPS, 1); + /* Nullify the metadata key so we don't try to close it later on. */ + registry->metadata_key = 0; goto error_consumer; } - /* Keep metadata key so we can identify it on the consumer side. */ - registry->metadata_key = metadata->key; - DBG2("UST metadata with key %" PRIu64 " created for app pid %d", metadata->key, app->pid); error_consumer: + lttng_fd_put(LTTNG_FD_APPS, 1); delete_ust_app_channel(-1, metadata, app); error: return ret; @@ -2748,15 +2883,18 @@ void ust_app_unregister(int sock) * session so the delete session will NOT push/close a second time. */ registry = get_session_registry(ua_sess); - if (registry) { + if (registry && !registry->metadata_closed) { /* Push metadata for application before freeing the application. */ (void) push_metadata(registry, ua_sess->consumer); /* * Don't ask to close metadata for global per UID buffers. Close - * metadata only on destroy trace session in this case. + * metadata only on destroy trace session in this case. Also, the + * previous push metadata could have flag the metadata registry to + * close so don't send a close command if closed. */ - if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID) { + if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID && + !registry->metadata_closed) { /* And ask to close it for this session registry. */ (void) close_metadata(registry, ua_sess->consumer); } @@ -2982,6 +3120,8 @@ error: /* * Free and clean all traceable apps of the global list. + * + * Should _NOT_ be called with RCU read-side lock held. */ void ust_app_clean_list(void) { @@ -3012,13 +3152,12 @@ void ust_app_clean_list(void) ret = lttng_ht_del(ust_app_ht_by_notify_sock, &iter); assert(!ret); } + rcu_read_unlock(); /* Destroy is done only when the ht is empty */ - lttng_ht_destroy(ust_app_ht); - lttng_ht_destroy(ust_app_ht_by_sock); - lttng_ht_destroy(ust_app_ht_by_notify_sock); - - rcu_read_unlock(); + ht_cleanup_push(ust_app_ht); + ht_cleanup_push(ust_app_ht_by_sock); + ht_cleanup_push(ust_app_ht_by_notify_sock); } /* @@ -3320,9 +3459,17 @@ int ust_app_create_channel_glb(struct ltt_ust_session *usess, assert(ua_sess); pthread_mutex_lock(&ua_sess->lock); - /* Create channel onto application. We don't need the chan ref. */ - ret = create_ust_app_channel(ua_sess, uchan, app, - LTTNG_UST_CHAN_PER_CPU, usess, NULL); + if (!strncmp(uchan->name, DEFAULT_METADATA_NAME, + sizeof(uchan->name))) { + struct ustctl_consumer_channel_attr attr; + copy_channel_attr_to_ustctl(&attr, &uchan->attr); + ret = create_ust_app_metadata(ua_sess, app, usess->consumer, + &attr); + } else { + /* Create channel onto application. We don't need the chan ref. */ + ret = create_ust_app_channel(ua_sess, uchan, app, + LTTNG_UST_CHAN_PER_CPU, usess, NULL); + } pthread_mutex_unlock(&ua_sess->lock); if (ret < 0) { if (ret == -ENOMEM) { @@ -3478,6 +3625,7 @@ int ust_app_create_event_glb(struct ltt_ust_session *usess, /* * Start tracing for a specific UST session and app. */ +static int ust_app_start_trace(struct ltt_ust_session *usess, struct ust_app *app) { int ret = 0; @@ -3517,8 +3665,11 @@ int ust_app_start_trace(struct ltt_ust_session *usess, struct ust_app *app) } } - /* Create the metadata for the application. */ - ret = create_ust_app_metadata(ua_sess, app, usess->consumer); + /* + * Create the metadata for the application. This returns gracefully if a + * metadata was already set for the session. + */ + ret = create_ust_app_metadata(ua_sess, app, usess->consumer, NULL); if (ret < 0) { goto error_unlock; } @@ -3567,12 +3718,11 @@ error_unlock: /* * Stop tracing for a specific UST session and app. */ +static int ust_app_stop_trace(struct ltt_ust_session *usess, struct ust_app *app) { int ret = 0; - struct lttng_ht_iter iter; struct ust_app_session *ua_sess; - struct ust_app_channel *ua_chan; struct ust_registry_session *registry; DBG("Stopping tracing for ust app pid %d", app->pid); @@ -3625,6 +3775,55 @@ int ust_app_stop_trace(struct ltt_ust_session *usess, struct ust_app *app) health_code_update(); + registry = get_session_registry(ua_sess); + assert(registry); + + if (!registry->metadata_closed) { + /* Push metadata for application before freeing the application. */ + (void) push_metadata(registry, ua_sess->consumer); + } + + pthread_mutex_unlock(&ua_sess->lock); +end_no_session: + rcu_read_unlock(); + health_code_update(); + return 0; + +error_rcu_unlock: + pthread_mutex_unlock(&ua_sess->lock); + rcu_read_unlock(); + health_code_update(); + return -1; +} + +/* + * Flush buffers for a specific UST session and app. + */ +static +int ust_app_flush_trace(struct ltt_ust_session *usess, struct ust_app *app) +{ + int ret = 0; + struct lttng_ht_iter iter; + struct ust_app_session *ua_sess; + struct ust_app_channel *ua_chan; + + DBG("Flushing buffers for ust app pid %d", app->pid); + + rcu_read_lock(); + + if (!app->compatible) { + goto end_no_session; + } + + ua_sess = lookup_session_by_app(usess, app); + if (ua_sess == NULL) { + goto end_no_session; + } + + pthread_mutex_lock(&ua_sess->lock); + + health_code_update(); + /* Flushing buffers */ cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan, node.node) { @@ -3648,22 +3847,11 @@ int ust_app_stop_trace(struct ltt_ust_session *usess, struct ust_app *app) health_code_update(); - registry = get_session_registry(ua_sess); - assert(registry); - /* Push metadata for application before freeing the application. */ - (void) push_metadata(registry, ua_sess->consumer); - pthread_mutex_unlock(&ua_sess->lock); end_no_session: rcu_read_unlock(); health_code_update(); return 0; - -error_rcu_unlock: - pthread_mutex_unlock(&ua_sess->lock); - rcu_read_unlock(); - health_code_update(); - return -1; } /* @@ -3748,9 +3936,21 @@ int ust_app_stop_trace_all(struct ltt_ust_session *usess) rcu_read_lock(); - /* Flush all per UID buffers associated to that session. */ - if (usess->buffer_type == LTTNG_BUFFER_PER_UID) { + cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) { + ret = ust_app_stop_trace(usess, app); + if (ret < 0) { + /* Continue to next apps even on error */ + continue; + } + } + + /* Flush buffers */ + switch (usess->buffer_type) { + case LTTNG_BUFFER_PER_UID: + { struct buffer_reg_uid *reg; + + /* Flush all per UID buffers associated to that session. */ cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) { struct buffer_reg_channel *reg_chan; struct consumer_socket *socket; @@ -3773,14 +3973,20 @@ int ust_app_stop_trace_all(struct ltt_ust_session *usess) (void) consumer_flush_channel(socket, reg_chan->consumer_key); } } + break; } - - cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) { - ret = ust_app_stop_trace(usess, app); - if (ret < 0) { - /* Continue to next apps even on error */ - continue; + case LTTNG_BUFFER_PER_PID: + cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) { + ret = ust_app_flush_trace(usess, app); + if (ret < 0) { + /* Continue to next apps even on error */ + continue; + } } + break; + default: + assert(0); + break; } rcu_read_unlock(); @@ -3865,14 +4071,31 @@ void ust_app_global_update(struct ltt_ust_session *usess, int sock) */ cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan, node.node) { - ret = do_create_channel(app, usess, ua_sess, ua_chan); - if (ret < 0) { - /* - * Stop everything. On error, the application failed, no more file - * descriptor are available or ENOMEM so stopping here is the only - * thing we can do for now. - */ - goto error_unlock; + /* + * For a metadata channel, handle it differently. + */ + if (!strncmp(ua_chan->name, DEFAULT_METADATA_NAME, + sizeof(ua_chan->name))) { + ret = create_ust_app_metadata(ua_sess, app, usess->consumer, + &ua_chan->attr); + if (ret < 0) { + goto error_unlock; + } + /* Remove it from the hash table and continue!. */ + ret = lttng_ht_del(ua_sess->channels, &iter); + assert(!ret); + delete_ust_app_channel(-1, ua_chan, app); + continue; + } else { + ret = do_create_channel(app, usess, ua_sess, ua_chan); + if (ret < 0) { + /* + * Stop everything. On error, the application failed, no more + * file descriptor are available or ENOMEM so stopping here is + * the only thing we can do for now. + */ + goto error_unlock; + } } cds_lfht_for_each_entry(ua_chan->ctx->ht, &iter_ctx.iter, ua_ctx, @@ -4249,12 +4472,19 @@ static int reply_ust_register_channel(int sock, int sobjd, int cobjd, DBG("Application socket %d is being teardown. Abort event notify", sock); ret = 0; + free(fields); goto error_rcu_unlock; } - /* Lookup channel by UST object descriptor. Should always be found. */ + /* Lookup channel by UST object descriptor. */ ua_chan = find_channel_by_objd(app, cobjd); - assert(ua_chan); + if (!ua_chan) { + DBG("Application channel is being teardown. Abort event notify"); + ret = 0; + free(fields); + goto error_rcu_unlock; + } + assert(ua_chan->session); ua_sess = ua_chan->session; @@ -4288,6 +4518,9 @@ static int reply_ust_register_channel(int sock, int sobjd, int cobjd, } else { /* Get current already assigned values. */ type = chan_reg->header_type; + free(fields); + /* Set to NULL so the error path does not do a double free. */ + fields = NULL; } /* Channel id is set during the object creation. */ chan_id = chan_reg->chan_id; @@ -4323,6 +4556,9 @@ error: pthread_mutex_unlock(®istry->lock); error_rcu_unlock: rcu_read_unlock(); + if (ret) { + free(fields); + } return ret; } @@ -4355,12 +4591,23 @@ static int add_event_ust_registry(int sock, int sobjd, int cobjd, char *name, DBG("Application socket %d is being teardown. Abort event notify", sock); ret = 0; + free(sig); + free(fields); + free(model_emf_uri); goto error_rcu_unlock; } - /* Lookup channel by UST object descriptor. Should always be found. */ + /* Lookup channel by UST object descriptor. */ ua_chan = find_channel_by_objd(app, cobjd); - assert(ua_chan); + if (!ua_chan) { + DBG("Application channel is being teardown. Abort event notify"); + ret = 0; + free(sig); + free(fields); + free(model_emf_uri); + goto error_rcu_unlock; + } + assert(ua_chan->session); ua_sess = ua_chan->session; @@ -4375,6 +4622,11 @@ static int add_event_ust_registry(int sock, int sobjd, int cobjd, char *name, pthread_mutex_lock(®istry->lock); + /* + * From this point on, this call acquires the ownership of the sig, fields + * and model_emf_uri meaning any free are done inside it if needed. These + * three variables MUST NOT be read/write after this. + */ ret_code = ust_registry_create_event(registry, chan_reg_key, sobjd, cobjd, name, sig, nr_fields, fields, loglevel, model_emf_uri, ua_sess->buffer_type, &event_id); @@ -4451,7 +4703,12 @@ int ust_app_recv_notify(int sock) goto error; } - /* Add event to the UST registry coming from the notify socket. */ + /* + * Add event to the UST registry coming from the notify socket. This + * call will free if needed the sig, fields and model_emf_uri. This + * code path loses the ownsership of these variables and transfer them + * to the this function. + */ ret = add_event_ust_registry(sock, sobjd, cobjd, name, sig, nr_fields, fields, loglevel, model_emf_uri); if (ret < 0) { @@ -4479,6 +4736,11 @@ int ust_app_recv_notify(int sock) goto error; } + /* + * The fields ownership are transfered to this function call meaning + * that if needed it will be freed. After this, it's invalid to access + * fields or clean it up. + */ ret = reply_ust_register_channel(sock, sobjd, cobjd, nr_fields, fields); if (ret < 0) { @@ -4572,3 +4834,78 @@ close_socket: call_rcu(&obj->head, close_notify_sock_rcu); } } + +/* + * Destroy a ust app data structure and free its memory. + */ +void ust_app_destroy(struct ust_app *app) +{ + if (!app) { + return; + } + + call_rcu(&app->pid_n.head, delete_ust_app_rcu); +} + +/* + * Take a snapshot for a given UST session. The snapshot is sent to the given + * output. + * + * Return 0 on success or else a negative value. + */ +int ust_app_snapshot_record(struct ltt_ust_session *usess, + struct snapshot_output *output, int wait) +{ + int ret = 0; + struct lttng_ht_iter iter; + struct ust_app *app; + + assert(usess); + assert(output); + + rcu_read_lock(); + + cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) { + struct consumer_socket *socket; + struct lttng_ht_iter chan_iter; + struct ust_app_channel *ua_chan; + struct ust_app_session *ua_sess; + struct ust_registry_session *registry; + + ua_sess = lookup_session_by_app(usess, app); + if (!ua_sess) { + /* Session not associated with this app. */ + continue; + } + + /* Get the right consumer socket for the application. */ + socket = consumer_find_socket_by_bitness(app->bits_per_long, + output->consumer); + if (!socket) { + ret = -EINVAL; + goto error; + } + + cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter, + ua_chan, node.node) { + ret = consumer_snapshot_channel(socket, ua_chan->key, output, 0, + ua_sess->euid, ua_sess->egid, ua_sess->path, wait); + if (ret < 0) { + goto error; + } + } + + registry = get_session_registry(ua_sess); + assert(registry); + ret = consumer_snapshot_channel(socket, registry->metadata_key, output, + 1, ua_sess->euid, ua_sess->egid, ua_sess->path, wait); + if (ret < 0) { + goto error; + } + + } + +error: + rcu_read_unlock(); + return ret; +}