X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fcmd.c;h=812c850faa73b9b4efb34b5030c6f46dd22c00d2;hp=211fc5a34df02b70de775c15880d526d26afe050;hb=804c90a84626aa4ccc82ab1821e40ff6e257f06c;hpb=2bba9e532ca1910822005ff7f67400a2e871467c diff --git a/src/bin/lttng-sessiond/cmd.c b/src/bin/lttng-sessiond/cmd.c index 211fc5a34..9362833c9 100644 --- a/src/bin/lttng-sessiond/cmd.c +++ b/src/bin/lttng-sessiond/cmd.c @@ -1,5 +1,6 @@ /* * Copyright (C) 2012 - David Goulet + * Copyright (C) 2016 - Jérémie Galarneau * * 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, as @@ -15,7 +16,7 @@ * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ -#define _GNU_SOURCE +#define _LGPL_SOURCE #include #include #include @@ -25,15 +26,21 @@ #include #include #include +#include +#include +#include #include "channel.h" #include "consumer.h" #include "event.h" -#include "health.h" +#include "health-sessiond.h" #include "kernel.h" #include "kernel-consumer.h" #include "lttng-sessiond.h" #include "utils.h" +#include "syscall.h" +#include "agent.h" +#include "buffer-registry.h" #include "cmd.h" @@ -46,6 +53,16 @@ static pthread_mutex_t relayd_net_seq_idx_lock = PTHREAD_MUTEX_INITIALIZER; static uint64_t relayd_net_seq_idx; +static int validate_event_name(const char *); +static int validate_ust_event_name(const char *); +static int cmd_enable_event_internal(struct ltt_session *session, + struct lttng_domain *domain, + char *channel_name, struct lttng_event *event, + char *filter_expression, + struct lttng_filter_bytecode *filter, + struct lttng_event_exclusion *exclusion, + int wpipe); + /* * Create a session path used by list_lttng_sessions for the case that the * session consumer is on the network. @@ -124,13 +141,105 @@ error: return ret; } +/* + * Get run-time attributes if the session has been started (discarded events, + * lost packets). + */ +static int get_kernel_runtime_stats(struct ltt_session *session, + struct ltt_kernel_channel *kchan, uint64_t *discarded_events, + uint64_t *lost_packets) +{ + int ret; + + if (!session->has_been_started) { + ret = 0; + *discarded_events = 0; + *lost_packets = 0; + goto end; + } + + ret = consumer_get_discarded_events(session->id, kchan->fd, + session->kernel_session->consumer, + discarded_events); + if (ret < 0) { + goto end; + } + + ret = consumer_get_lost_packets(session->id, kchan->fd, + session->kernel_session->consumer, + lost_packets); + if (ret < 0) { + goto end; + } + +end: + return ret; +} + +/* + * Get run-time attributes if the session has been started (discarded events, + * lost packets). + */ +static int get_ust_runtime_stats(struct ltt_session *session, + struct ltt_ust_channel *uchan, uint64_t *discarded_events, + uint64_t *lost_packets) +{ + int ret; + struct ltt_ust_session *usess; + + if (!discarded_events || !lost_packets) { + ret = -1; + goto end; + } + + usess = session->ust_session; + assert(discarded_events); + assert(lost_packets); + + if (!usess || !session->has_been_started) { + *discarded_events = 0; + *lost_packets = 0; + ret = 0; + goto end; + } + + if (usess->buffer_type == LTTNG_BUFFER_PER_UID) { + ret = ust_app_uid_get_channel_runtime_stats(usess->id, + &usess->buffer_reg_uid_list, + usess->consumer, uchan->id, + uchan->attr.overwrite, + discarded_events, + lost_packets); + } else if (usess->buffer_type == LTTNG_BUFFER_PER_PID) { + ret = ust_app_pid_get_channel_runtime_stats(usess, + uchan, usess->consumer, + uchan->attr.overwrite, + discarded_events, + lost_packets); + if (ret < 0) { + goto end; + } + *discarded_events += uchan->per_pid_closed_app_discarded; + *lost_packets += uchan->per_pid_closed_app_lost; + } else { + ERR("Unsupported buffer type"); + assert(0); + ret = -1; + goto end; + } + +end: + return ret; +} + /* * Fill lttng_channel array of all channels. */ -static void list_lttng_channels(int domain, struct ltt_session *session, - struct lttng_channel *channels) +static void list_lttng_channels(enum lttng_domain_type domain, + struct ltt_session *session, struct lttng_channel *channels, + struct lttcomm_channel_extended *chan_exts) { - int i = 0; + int i = 0, ret; struct ltt_kernel_channel *kchan; DBG("Listing channels for session %s", session->name); @@ -141,9 +250,19 @@ static void list_lttng_channels(int domain, struct ltt_session *session, if (session->kernel_session != NULL) { cds_list_for_each_entry(kchan, &session->kernel_session->channel_list.head, list) { + uint64_t discarded_events, lost_packets; + + ret = get_kernel_runtime_stats(session, kchan, + &discarded_events, &lost_packets); + if (ret < 0) { + goto end; + } /* Copy lttng_channel struct to array */ memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel)); channels[i].enabled = kchan->enabled; + chan_exts[i].discarded_events = + discarded_events; + chan_exts[i].lost_packets = lost_packets; i++; } } @@ -156,6 +275,8 @@ static void list_lttng_channels(int domain, struct ltt_session *session, rcu_read_lock(); cds_lfht_for_each_entry(session->ust_session->domain_global.channels->ht, &iter.iter, uchan, node.node) { + uint64_t discarded_events = 0, lost_packets = 0; + strncpy(channels[i].name, uchan->name, LTTNG_SYMBOL_NAME_LEN); channels[i].attr.overwrite = uchan->attr.overwrite; channels[i].attr.subbuf_size = uchan->attr.subbuf_size; @@ -165,12 +286,32 @@ static void list_lttng_channels(int domain, struct ltt_session *session, channels[i].attr.read_timer_interval = uchan->attr.read_timer_interval; channels[i].enabled = uchan->enabled; + channels[i].attr.tracefile_size = uchan->tracefile_size; + channels[i].attr.tracefile_count = uchan->tracefile_count; + + /* + * Map enum lttng_ust_output to enum lttng_event_output. + */ switch (uchan->attr.output) { case LTTNG_UST_MMAP: - default: channels[i].attr.output = LTTNG_EVENT_MMAP; break; + default: + /* + * LTTNG_UST_MMAP is the only supported UST + * output mode. + */ + assert(0); + break; + } + + ret = get_ust_runtime_stats(session, uchan, + &discarded_events, &lost_packets); + if (ret < 0) { + break; } + chan_exts[i].discarded_events = discarded_events; + chan_exts[i].lost_packets = lost_packets; i++; } rcu_read_unlock(); @@ -179,13 +320,147 @@ static void list_lttng_channels(int domain, struct ltt_session *session, default: break; } + +end: + return; +} + +static void increment_extended_len(const char *filter_expression, + struct lttng_event_exclusion *exclusion, size_t *extended_len) +{ + *extended_len += sizeof(struct lttcomm_event_extended_header); + + if (filter_expression) { + *extended_len += strlen(filter_expression) + 1; + } + + if (exclusion) { + *extended_len += exclusion->count * LTTNG_SYMBOL_NAME_LEN; + } +} + +static void append_extended_info(const char *filter_expression, + struct lttng_event_exclusion *exclusion, void **extended_at) +{ + struct lttcomm_event_extended_header extended_header; + size_t filter_len = 0; + size_t nb_exclusions = 0; + + if (filter_expression) { + filter_len = strlen(filter_expression) + 1; + } + + if (exclusion) { + nb_exclusions = exclusion->count; + } + + /* Set header fields */ + extended_header.filter_len = filter_len; + extended_header.nb_exclusions = nb_exclusions; + + /* Copy header */ + memcpy(*extended_at, &extended_header, sizeof(extended_header)); + *extended_at += sizeof(extended_header); + + /* Copy filter string */ + if (filter_expression) { + memcpy(*extended_at, filter_expression, filter_len); + *extended_at += filter_len; + } + + /* Copy exclusion names */ + if (exclusion) { + size_t len = nb_exclusions * LTTNG_SYMBOL_NAME_LEN; + + memcpy(*extended_at, &exclusion->names, len); + *extended_at += len; + } +} + +/* + * Create a list of agent domain events. + * + * Return number of events in list on success or else a negative value. + */ +static int list_lttng_agent_events(struct agent *agt, + struct lttng_event **events, size_t *total_size) +{ + int i = 0, ret = 0; + unsigned int nb_event = 0; + struct agent_event *event; + struct lttng_event *tmp_events; + struct lttng_ht_iter iter; + size_t extended_len = 0; + void *extended_at; + + assert(agt); + assert(events); + + DBG3("Listing agent events"); + + rcu_read_lock(); + nb_event = lttng_ht_get_count(agt->events); + rcu_read_unlock(); + if (nb_event == 0) { + ret = nb_event; + *total_size = 0; + goto error; + } + + /* Compute required extended infos size */ + extended_len = nb_event * sizeof(struct lttcomm_event_extended_header); + + /* + * This is only valid because the commands which add events are + * processed in the same thread as the listing. + */ + rcu_read_lock(); + cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) { + increment_extended_len(event->filter_expression, NULL, + &extended_len); + } + rcu_read_unlock(); + + *total_size = nb_event * sizeof(*tmp_events) + extended_len; + tmp_events = zmalloc(*total_size); + if (!tmp_events) { + PERROR("zmalloc agent events session"); + ret = -LTTNG_ERR_FATAL; + goto error; + } + + extended_at = ((uint8_t *) tmp_events) + + nb_event * sizeof(struct lttng_event); + + rcu_read_lock(); + cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) { + strncpy(tmp_events[i].name, event->name, sizeof(tmp_events[i].name)); + tmp_events[i].name[sizeof(tmp_events[i].name) - 1] = '\0'; + tmp_events[i].enabled = event->enabled; + tmp_events[i].loglevel = event->loglevel_value; + tmp_events[i].loglevel_type = event->loglevel_type; + i++; + + /* Append extended info */ + append_extended_info(event->filter_expression, NULL, + &extended_at); + } + rcu_read_unlock(); + + *events = tmp_events; + ret = nb_event; + +error: + assert(nb_event == i); + return ret; } /* * Create a list of ust global domain events. */ static int list_lttng_ust_global_events(char *channel_name, - struct ltt_ust_domain_global *ust_global, struct lttng_event **events) + struct ltt_ust_domain_global *ust_global, + struct lttng_event **events, size_t *total_size) { int i = 0, ret = 0; unsigned int nb_event = 0; @@ -194,6 +469,8 @@ static int list_lttng_ust_global_events(char *channel_name, struct ltt_ust_channel *uchan; struct ltt_ust_event *uevent; struct lttng_event *tmp; + size_t extended_len = 0; + void *extended_at; DBG("Listing UST global events for channel %s", channel_name); @@ -203,27 +480,51 @@ static int list_lttng_ust_global_events(char *channel_name, node = lttng_ht_iter_get_node_str(&iter); if (node == NULL) { ret = LTTNG_ERR_UST_CHAN_NOT_FOUND; - goto error; + goto end; } uchan = caa_container_of(&node->node, struct ltt_ust_channel, node.node); - nb_event += lttng_ht_get_count(uchan->events); - + nb_event = lttng_ht_get_count(uchan->events); if (nb_event == 0) { ret = nb_event; - goto error; + *total_size = 0; + goto end; } DBG3("Listing UST global %d events", nb_event); - tmp = zmalloc(nb_event * sizeof(struct lttng_event)); + /* Compute required extended infos size */ + cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) { + if (uevent->internal) { + nb_event--; + continue; + } + + increment_extended_len(uevent->filter_expression, + uevent->exclusion, &extended_len); + } + if (nb_event == 0) { + /* All events are internal, skip. */ + ret = 0; + *total_size = 0; + goto end; + } + + *total_size = nb_event * sizeof(struct lttng_event) + extended_len; + tmp = zmalloc(*total_size); if (tmp == NULL) { - ret = LTTNG_ERR_FATAL; - goto error; + ret = -LTTNG_ERR_FATAL; + goto end; } + extended_at = ((uint8_t *) tmp) + nb_event * sizeof(struct lttng_event); + cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) { + if (uevent->internal) { + /* This event should remain hidden from clients */ + continue; + } strncpy(tmp[i].name, uevent->attr.name, LTTNG_SYMBOL_NAME_LEN); tmp[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0'; tmp[i].enabled = uevent->enabled; @@ -255,13 +556,19 @@ static int list_lttng_ust_global_events(char *channel_name, if (uevent->filter) { tmp[i].filter = 1; } + if (uevent->exclusion) { + tmp[i].exclusion = 1; + } i++; + + /* Append extended info */ + append_extended_info(uevent->filter_expression, + uevent->exclusion, &extended_at); } ret = nb_event; *events = tmp; - -error: +end: rcu_read_unlock(); return ret; } @@ -270,12 +577,15 @@ error: * Fill lttng_event array of all kernel events in the channel. */ static int list_lttng_kernel_events(char *channel_name, - struct ltt_kernel_session *kernel_session, struct lttng_event **events) + struct ltt_kernel_session *kernel_session, + struct lttng_event **events, size_t *total_size) { int i = 0, ret; unsigned int nb_event; struct ltt_kernel_event *event; struct ltt_kernel_channel *kchan; + size_t extended_len = 0; + void *extended_at; kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session); if (kchan == NULL) { @@ -288,20 +598,34 @@ static int list_lttng_kernel_events(char *channel_name, DBG("Listing events for channel %s", kchan->channel->name); if (nb_event == 0) { + *total_size = 0; + *events = NULL; goto end; } - *events = zmalloc(nb_event * sizeof(struct lttng_event)); + /* Compute required extended infos size */ + cds_list_for_each_entry(event, &kchan->events_list.head, list) { + increment_extended_len(event->filter_expression, NULL, + &extended_len); + } + + *total_size = nb_event * sizeof(struct lttng_event) + extended_len; + *events = zmalloc(*total_size); if (*events == NULL) { ret = LTTNG_ERR_FATAL; goto error; } + extended_at = ((void *) *events) + + nb_event * sizeof(struct lttng_event); + /* Kernel channels */ cds_list_for_each_entry(event, &kchan->events_list.head , list) { strncpy((*events)[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN); (*events)[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0'; (*events)[i].enabled = event->enabled; + (*events)[i].filter = + (unsigned char) !!event->filter_expression; switch (event->event->instrumentation) { case LTTNG_KERNEL_TRACEPOINT: @@ -333,6 +657,10 @@ static int list_lttng_kernel_events(char *channel_name, break; } i++; + + /* Append extended info */ + append_extended_info(event->filter_expression, NULL, + &extended_at); } end: @@ -348,7 +676,8 @@ error: * domain adding the default trace directory. */ static int add_uri_to_consumer(struct consumer_output *consumer, - struct lttng_uri *uri, int domain, const char *session_name) + struct lttng_uri *uri, enum lttng_domain_type domain, + const char *session_name) { int ret = LTTNG_OK; const char *default_trace_dir; @@ -405,6 +734,7 @@ static int add_uri_to_consumer(struct consumer_output *consumer, * URI was the same in the consumer so we do not append the subdir * again so to not duplicate output dir. */ + ret = LTTNG_OK; goto error; } @@ -461,9 +791,6 @@ static int init_kernel_tracing(struct ltt_kernel_session *session) if (session->consumer_fds_sent == 0 && session->consumer != NULL) { cds_lfht_for_each_entry(session->consumer->socks->ht, &iter.iter, socket, node.node) { - /* Code flow error */ - assert(socket->fd >= 0); - pthread_mutex_lock(socket->lock); ret = kernel_consumer_send_session(socket, session); pthread_mutex_unlock(socket->lock); @@ -486,7 +813,8 @@ error: * Else, it's stays untouched and a lttcomm error code is returned. */ static int create_connect_relayd(struct lttng_uri *uri, - struct lttcomm_relayd_sock **relayd_sock) + struct lttcomm_relayd_sock **relayd_sock, + struct consumer_output *consumer) { int ret; struct lttcomm_relayd_sock *rsock; @@ -522,6 +850,8 @@ static int create_connect_relayd(struct lttng_uri *uri, ret = LTTNG_ERR_RELAYD_VERSION_FAIL; goto close_sock; } + consumer->relay_major_version = rsock->major; + consumer->relay_minor_version = rsock->minor; } else if (uri->stype == LTTNG_STREAM_DATA) { DBG3("Creating relayd data socket from URI"); } else { @@ -547,15 +877,17 @@ error: /* * Connect to the relayd using URI and send the socket to the right consumer. */ -static int send_consumer_relayd_socket(int domain, unsigned int session_id, - struct lttng_uri *relayd_uri, struct consumer_output *consumer, - struct consumer_socket *consumer_sock) +static int send_consumer_relayd_socket(enum lttng_domain_type domain, + unsigned int session_id, struct lttng_uri *relayd_uri, + struct consumer_output *consumer, + struct consumer_socket *consumer_sock, + char *session_name, char *hostname, int session_live_timer) { int ret; struct lttcomm_relayd_sock *rsock = NULL; /* Connect to relayd and make version check if uri is the control. */ - ret = create_connect_relayd(relayd_uri, &rsock); + ret = create_connect_relayd(relayd_uri, &rsock, consumer); if (ret != LTTNG_OK) { goto error; } @@ -575,7 +907,8 @@ static int send_consumer_relayd_socket(int domain, unsigned int session_id, /* Send relayd socket to consumer. */ ret = consumer_send_relayd_socket(consumer_sock, rsock, consumer, - relayd_uri->stype, session_id); + relayd_uri->stype, session_id, + session_name, hostname, session_live_timer); if (ret < 0) { ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL; goto close_sock; @@ -616,8 +949,10 @@ error: * helper function to facilitate sending the information to the consumer for a * session. */ -static int send_consumer_relayd_sockets(int domain, unsigned int session_id, - struct consumer_output *consumer, struct consumer_socket *sock) +static int send_consumer_relayd_sockets(enum lttng_domain_type domain, + unsigned int session_id, struct consumer_output *consumer, + struct consumer_socket *sock, char *session_name, + char *hostname, int session_live_timer) { int ret = LTTNG_OK; @@ -627,7 +962,8 @@ static int send_consumer_relayd_sockets(int domain, unsigned int session_id, /* Sending control relayd socket. */ if (!sock->control_sock_sent) { ret = send_consumer_relayd_socket(domain, session_id, - &consumer->dst.net.control, consumer, sock); + &consumer->dst.net.control, consumer, sock, + session_name, hostname, session_live_timer); if (ret != LTTNG_OK) { goto error; } @@ -636,7 +972,8 @@ static int send_consumer_relayd_sockets(int domain, unsigned int session_id, /* Sending data relayd socket. */ if (!sock->data_sock_sent) { ret = send_consumer_relayd_socket(domain, session_id, - &consumer->dst.net.data, consumer, sock); + &consumer->dst.net.data, consumer, sock, + session_name, hostname, session_live_timer); if (ret != LTTNG_OK) { goto error; } @@ -673,12 +1010,11 @@ int cmd_setup_relayd(struct ltt_session *session) /* For each consumer socket, send relayd sockets */ cds_lfht_for_each_entry(usess->consumer->socks->ht, &iter.iter, socket, node.node) { - /* Code flow error */ - assert(socket->fd >= 0); - pthread_mutex_lock(socket->lock); ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_UST, session->id, - usess->consumer, socket); + usess->consumer, socket, + session->name, session->hostname, + session->live_timer); pthread_mutex_unlock(socket->lock); if (ret != LTTNG_OK) { goto error; @@ -686,18 +1022,21 @@ int cmd_setup_relayd(struct ltt_session *session) /* Session is now ready for network streaming. */ session->net_handle = 1; } + session->consumer->relay_major_version = + usess->consumer->relay_major_version; + session->consumer->relay_minor_version = + usess->consumer->relay_minor_version; } if (ksess && ksess->consumer && ksess->consumer->type == CONSUMER_DST_NET && ksess->consumer->enabled) { cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter, socket, node.node) { - /* Code flow error */ - assert(socket->fd >= 0); - pthread_mutex_lock(socket->lock); ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_KERNEL, session->id, - ksess->consumer, socket); + ksess->consumer, socket, + session->name, session->hostname, + session->live_timer); pthread_mutex_unlock(socket->lock); if (ret != LTTNG_OK) { goto error; @@ -705,6 +1044,10 @@ int cmd_setup_relayd(struct ltt_session *session) /* Session is now ready for network streaming. */ session->net_handle = 1; } + session->consumer->relay_major_version = + ksess->consumer->relay_major_version; + session->consumer->relay_minor_version = + ksess->consumer->relay_minor_version; } error: @@ -721,7 +1064,7 @@ static int start_kernel_session(struct ltt_kernel_session *ksess, int wpipe) struct ltt_kernel_channel *kchan; /* Open kernel metadata */ - if (ksess->metadata == NULL) { + if (ksess->metadata == NULL && ksess->output_traces) { ret = kernel_open_metadata(ksess); if (ret < 0) { ret = LTTNG_ERR_KERN_META_FAIL; @@ -730,7 +1073,7 @@ static int start_kernel_session(struct ltt_kernel_session *ksess, int wpipe) } /* Open kernel metadata stream */ - if (ksess->metadata_stream_fd < 0) { + if (ksess->metadata && ksess->metadata_stream_fd < 0) { ret = kernel_open_metadata_stream(ksess); if (ret < 0) { ERR("Kernel create metadata stream failed"); @@ -769,7 +1112,7 @@ static int start_kernel_session(struct ltt_kernel_session *ksess, int wpipe) /* Quiescent wait after starting trace */ kernel_wait_quiescent(kernel_tracer_fd); - ksess->started = 1; + ksess->active = 1; ret = LTTNG_OK; @@ -780,8 +1123,8 @@ error: /* * Command LTTNG_DISABLE_CHANNEL processed by the client thread. */ -int cmd_disable_channel(struct ltt_session *session, int domain, - char *channel_name) +int cmd_disable_channel(struct ltt_session *session, + enum lttng_domain_type domain, char *channel_name) { int ret; struct ltt_ust_session *usess; @@ -821,11 +1164,6 @@ int cmd_disable_channel(struct ltt_session *session, int domain, } break; } -#if 0 - case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN: - case LTTNG_DOMAIN_UST_EXEC_NAME: - case LTTNG_DOMAIN_UST_PID: -#endif default: ret = LTTNG_ERR_UNKNOWN_DOMAIN; goto error; @@ -839,47 +1177,25 @@ error: } /* - * Command LTTNG_ENABLE_CHANNEL processed by the client thread. + * Command LTTNG_TRACK_PID processed by the client thread. * - * The wpipe arguments is used as a notifier for the kernel thread. + * Called with session lock held. */ -int cmd_enable_channel(struct ltt_session *session, - struct lttng_domain *domain, struct lttng_channel *attr, int wpipe) +int cmd_track_pid(struct ltt_session *session, enum lttng_domain_type domain, + int pid) { int ret; - struct ltt_ust_session *usess = session->ust_session; - struct lttng_ht *chan_ht; - - assert(session); - assert(attr); - assert(domain); - - DBG("Enabling channel %s for session %s", attr->name, session->name); - - /* - * Don't try to enable a channel if the session has been started at - * some point in time before. The tracer does not allow it. - */ - if (session->started) { - ret = LTTNG_ERR_TRACE_ALREADY_STARTED; - goto error; - } rcu_read_lock(); - switch (domain->type) { + switch (domain) { case LTTNG_DOMAIN_KERNEL: { - struct ltt_kernel_channel *kchan; + struct ltt_kernel_session *ksess; - kchan = trace_kernel_get_channel_by_name(attr->name, - session->kernel_session); - if (kchan == NULL) { - ret = channel_kernel_create(session->kernel_session, attr, wpipe); - } else { - ret = channel_kernel_enable(session->kernel_session, kchan); - } + ksess = session->kernel_session; + ret = kernel_track_pid(ksess, pid); if (ret != LTTNG_OK) { goto error; } @@ -889,15 +1205,13 @@ int cmd_enable_channel(struct ltt_session *session, } case LTTNG_DOMAIN_UST: { - struct ltt_ust_channel *uchan; + struct ltt_ust_session *usess; - chan_ht = usess->domain_global.channels; + usess = session->ust_session; - uchan = trace_ust_find_channel_by_name(chan_ht, attr->name); - if (uchan == NULL) { - ret = channel_ust_create(usess, attr, domain->buf_type); - } else { - ret = channel_ust_enable(usess, uchan); + ret = trace_ust_track_pid(usess, pid); + if (ret != LTTNG_OK) { + goto error; } break; } @@ -906,17 +1220,20 @@ int cmd_enable_channel(struct ltt_session *session, goto error; } + ret = LTTNG_OK; + error: rcu_read_unlock(); return ret; } - /* - * Command LTTNG_DISABLE_EVENT processed by the client thread. + * Command LTTNG_UNTRACK_PID processed by the client thread. + * + * Called with session lock held. */ -int cmd_disable_event(struct ltt_session *session, int domain, - char *channel_name, char *event_name) +int cmd_untrack_pid(struct ltt_session *session, enum lttng_domain_type domain, + int pid) { int ret; @@ -925,18 +1242,11 @@ int cmd_disable_event(struct ltt_session *session, int domain, switch (domain) { case LTTNG_DOMAIN_KERNEL: { - struct ltt_kernel_channel *kchan; struct ltt_kernel_session *ksess; ksess = session->kernel_session; - kchan = trace_kernel_get_channel_by_name(channel_name, ksess); - if (kchan == NULL) { - ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND; - goto error; - } - - ret = event_kernel_disable_tracepoint(kchan, event_name); + ret = kernel_untrack_pid(ksess, pid); if (ret != LTTNG_OK) { goto error; } @@ -946,34 +1256,18 @@ int cmd_disable_event(struct ltt_session *session, int domain, } case LTTNG_DOMAIN_UST: { - struct ltt_ust_channel *uchan; struct ltt_ust_session *usess; usess = session->ust_session; - uchan = trace_ust_find_channel_by_name(usess->domain_global.channels, - channel_name); - if (uchan == NULL) { - ret = LTTNG_ERR_UST_CHAN_NOT_FOUND; - goto error; - } - - ret = event_ust_disable_tracepoint(usess, uchan, event_name); + ret = trace_ust_untrack_pid(usess, pid); if (ret != LTTNG_OK) { goto error; } - - DBG3("Disable UST event %s in channel %s completed", event_name, - channel_name); break; } -#if 0 - case LTTNG_DOMAIN_UST_EXEC_NAME: - case LTTNG_DOMAIN_UST_PID: - case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN: -#endif default: - ret = LTTNG_ERR_UND; + ret = LTTNG_ERR_UNKNOWN_DOMAIN; goto error; } @@ -985,84 +1279,340 @@ error: } /* - * Command LTTNG_DISABLE_ALL_EVENT processed by the client thread. + * Command LTTNG_ENABLE_CHANNEL processed by the client thread. + * + * The wpipe arguments is used as a notifier for the kernel thread. */ -int cmd_disable_event_all(struct ltt_session *session, int domain, - char *channel_name) +int cmd_enable_channel(struct ltt_session *session, + struct lttng_domain *domain, struct lttng_channel *attr, int wpipe) { int ret; + struct ltt_ust_session *usess = session->ust_session; + struct lttng_ht *chan_ht; + size_t len; - rcu_read_lock(); + assert(session); + assert(attr); + assert(domain); - switch (domain) { - case LTTNG_DOMAIN_KERNEL: - { - struct ltt_kernel_session *ksess; - struct ltt_kernel_channel *kchan; + len = lttng_strnlen(attr->name, sizeof(attr->name)); - ksess = session->kernel_session; + /* Validate channel name */ + if (attr->name[0] == '.' || + memchr(attr->name, '/', len) != NULL) { + ret = LTTNG_ERR_INVALID_CHANNEL_NAME; + goto end; + } - kchan = trace_kernel_get_channel_by_name(channel_name, ksess); - if (kchan == NULL) { - ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND; - goto error; - } + DBG("Enabling channel %s for session %s", attr->name, session->name); - ret = event_kernel_disable_all(kchan); - if (ret != LTTNG_OK) { - goto error; - } + rcu_read_lock(); + + /* + * Don't try to enable a channel if the session has been started at + * some point in time before. The tracer does not allow it. + */ + if (session->has_been_started) { + ret = LTTNG_ERR_TRACE_ALREADY_STARTED; + goto error; + } + + /* + * If the session is a live session, remove the switch timer, the + * live timer does the same thing but sends also synchronisation + * beacons for inactive streams. + */ + if (session->live_timer > 0) { + attr->attr.live_timer_interval = session->live_timer; + attr->attr.switch_timer_interval = 0; + } + + /* + * The ringbuffer (both in user space and kernel) behave badly in overwrite + * mode and with less than 2 subbuf so block it right away and send back an + * invalid attribute error. + */ + if (attr->attr.overwrite && attr->attr.num_subbuf < 2) { + ret = LTTNG_ERR_INVALID; + goto error; + } + + switch (domain->type) { + case LTTNG_DOMAIN_KERNEL: + { + struct ltt_kernel_channel *kchan; + + kchan = trace_kernel_get_channel_by_name(attr->name, + session->kernel_session); + if (kchan == NULL) { + ret = channel_kernel_create(session->kernel_session, attr, wpipe); + if (attr->name[0] != '\0') { + session->kernel_session->has_non_default_channel = 1; + } + } else { + ret = channel_kernel_enable(session->kernel_session, kchan); + } + + if (ret != LTTNG_OK) { + goto error; + } kernel_wait_quiescent(kernel_tracer_fd); break; } case LTTNG_DOMAIN_UST: + case LTTNG_DOMAIN_JUL: + case LTTNG_DOMAIN_LOG4J: + case LTTNG_DOMAIN_PYTHON: { - struct ltt_ust_session *usess; struct ltt_ust_channel *uchan; + /* + * FIXME + * + * Current agent implementation limitations force us to allow + * only one channel at once in "agent" subdomains. Each + * subdomain has a default channel name which must be strictly + * adhered to. + */ + if (domain->type == LTTNG_DOMAIN_JUL) { + if (strncmp(attr->name, DEFAULT_JUL_CHANNEL_NAME, + LTTNG_SYMBOL_NAME_LEN)) { + ret = LTTNG_ERR_INVALID_CHANNEL_NAME; + goto error; + } + } else if (domain->type == LTTNG_DOMAIN_LOG4J) { + if (strncmp(attr->name, DEFAULT_LOG4J_CHANNEL_NAME, + LTTNG_SYMBOL_NAME_LEN)) { + ret = LTTNG_ERR_INVALID_CHANNEL_NAME; + goto error; + } + } else if (domain->type == LTTNG_DOMAIN_PYTHON) { + if (strncmp(attr->name, DEFAULT_PYTHON_CHANNEL_NAME, + LTTNG_SYMBOL_NAME_LEN)) { + ret = LTTNG_ERR_INVALID_CHANNEL_NAME; + goto error; + } + } + + chan_ht = usess->domain_global.channels; + + uchan = trace_ust_find_channel_by_name(chan_ht, attr->name); + if (uchan == NULL) { + ret = channel_ust_create(usess, attr, domain->buf_type); + if (attr->name[0] != '\0') { + usess->has_non_default_channel = 1; + } + } else { + ret = channel_ust_enable(usess, uchan); + } + break; + } + default: + ret = LTTNG_ERR_UNKNOWN_DOMAIN; + goto error; + } + +error: + rcu_read_unlock(); +end: + return ret; +} + +/* + * Command LTTNG_DISABLE_EVENT processed by the client thread. + */ +int cmd_disable_event(struct ltt_session *session, + enum lttng_domain_type domain, char *channel_name, + struct lttng_event *event) +{ + int ret; + char *event_name; + + DBG("Disable event command for event \'%s\'", event->name); + + event_name = event->name; + if (validate_event_name(event_name)) { + ret = LTTNG_ERR_INVALID_EVENT_NAME; + goto error; + } + + /* Error out on unhandled search criteria */ + if (event->loglevel_type || event->loglevel != -1 || event->enabled + || event->pid || event->filter || event->exclusion) { + ret = LTTNG_ERR_UNK; + goto error; + } + + rcu_read_lock(); + + switch (domain) { + case LTTNG_DOMAIN_KERNEL: + { + struct ltt_kernel_channel *kchan; + struct ltt_kernel_session *ksess; + + ksess = session->kernel_session; + + /* + * If a non-default channel has been created in the + * session, explicitely require that -c chan_name needs + * to be provided. + */ + if (ksess->has_non_default_channel && channel_name[0] == '\0') { + ret = LTTNG_ERR_NEED_CHANNEL_NAME; + goto error_unlock; + } + + kchan = trace_kernel_get_channel_by_name(channel_name, ksess); + if (kchan == NULL) { + ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND; + goto error_unlock; + } + + switch (event->type) { + case LTTNG_EVENT_ALL: + case LTTNG_EVENT_TRACEPOINT: + case LTTNG_EVENT_SYSCALL: + case LTTNG_EVENT_PROBE: + case LTTNG_EVENT_FUNCTION: + case LTTNG_EVENT_FUNCTION_ENTRY:/* fall-through */ + if (event_name[0] == '\0') { + ret = event_kernel_disable_event(kchan, + NULL, event->type); + } else { + ret = event_kernel_disable_event(kchan, + event_name, event->type); + } + if (ret != LTTNG_OK) { + goto error_unlock; + } + break; + default: + ret = LTTNG_ERR_UNK; + goto error_unlock; + } + + kernel_wait_quiescent(kernel_tracer_fd); + break; + } + case LTTNG_DOMAIN_UST: + { + struct ltt_ust_channel *uchan; + struct ltt_ust_session *usess; + usess = session->ust_session; + if (validate_ust_event_name(event_name)) { + ret = LTTNG_ERR_INVALID_EVENT_NAME; + goto error_unlock; + } + + /* + * If a non-default channel has been created in the + * session, explicitly require that -c chan_name needs + * to be provided. + */ + if (usess->has_non_default_channel && channel_name[0] == '\0') { + ret = LTTNG_ERR_NEED_CHANNEL_NAME; + goto error_unlock; + } + uchan = trace_ust_find_channel_by_name(usess->domain_global.channels, channel_name); if (uchan == NULL) { ret = LTTNG_ERR_UST_CHAN_NOT_FOUND; - goto error; + goto error_unlock; } - ret = event_ust_disable_all_tracepoints(usess, uchan); - if (ret != 0) { - goto error; + switch (event->type) { + case LTTNG_EVENT_ALL: + /* + * An empty event name means that everything + * should be disabled. + */ + if (event->name[0] == '\0') { + ret = event_ust_disable_all_tracepoints(usess, uchan); + } else { + ret = event_ust_disable_tracepoint(usess, uchan, + event_name); + } + if (ret != LTTNG_OK) { + goto error_unlock; + } + break; + default: + ret = LTTNG_ERR_UNK; + goto error_unlock; + } + + DBG3("Disable UST event %s in channel %s completed", event_name, + channel_name); + break; + } + case LTTNG_DOMAIN_LOG4J: + case LTTNG_DOMAIN_JUL: + case LTTNG_DOMAIN_PYTHON: + { + struct agent *agt; + struct ltt_ust_session *usess = session->ust_session; + + assert(usess); + + switch (event->type) { + case LTTNG_EVENT_ALL: + break; + default: + ret = LTTNG_ERR_UNK; + goto error_unlock; } - DBG3("Disable all UST events in channel %s completed", channel_name); + agt = trace_ust_find_agent(usess, domain); + if (!agt) { + ret = -LTTNG_ERR_UST_EVENT_NOT_FOUND; + goto error_unlock; + } + /* + * An empty event name means that everything + * should be disabled. + */ + if (event->name[0] == '\0') { + ret = event_agent_disable_all(usess, agt); + } else { + ret = event_agent_disable(usess, agt, event_name); + } + if (ret != LTTNG_OK) { + goto error_unlock; + } break; } -#if 0 - case LTTNG_DOMAIN_UST_EXEC_NAME: - case LTTNG_DOMAIN_UST_PID: - case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN: -#endif default: ret = LTTNG_ERR_UND; - goto error; + goto error_unlock; } ret = LTTNG_OK; -error: +error_unlock: rcu_read_unlock(); +error: return ret; } /* * Command LTTNG_ADD_CONTEXT processed by the client thread. */ -int cmd_add_context(struct ltt_session *session, int domain, +int cmd_add_context(struct ltt_session *session, enum lttng_domain_type domain, char *channel_name, struct lttng_event_context *ctx, int kwpipe) { int ret, chan_kern_created = 0, chan_ust_created = 0; + char *app_ctx_provider_name = NULL, *app_ctx_name = NULL; + + if (ctx->ctx == LTTNG_EVENT_CONTEXT_APP_CONTEXT) { + app_ctx_provider_name = ctx->u.app_ctx.provider_name; + app_ctx_name = ctx->u.app_ctx.ctx_name; + } switch (domain) { case LTTNG_DOMAIN_KERNEL: @@ -1076,20 +1626,43 @@ int cmd_add_context(struct ltt_session *session, int domain, } chan_kern_created = 1; } - /* Add kernel context to kernel tracer */ ret = context_kernel_add(session->kernel_session, ctx, channel_name); if (ret != LTTNG_OK) { goto error; } break; + case LTTNG_DOMAIN_JUL: + case LTTNG_DOMAIN_LOG4J: + { + /* + * Validate channel name. + * If no channel name is given and the domain is JUL or LOG4J, + * set it to the appropriate domain-specific channel name. If + * a name is provided but does not match the expexted channel + * name, return an error. + */ + if (domain == LTTNG_DOMAIN_JUL && *channel_name && + strcmp(channel_name, + DEFAULT_JUL_CHANNEL_NAME)) { + ret = LTTNG_ERR_UST_CHAN_NOT_FOUND; + goto error; + } else if (domain == LTTNG_DOMAIN_LOG4J && *channel_name && + strcmp(channel_name, + DEFAULT_LOG4J_CHANNEL_NAME)) { + ret = LTTNG_ERR_UST_CHAN_NOT_FOUND; + goto error; + } + /* break is _not_ missing here. */ + } case LTTNG_DOMAIN_UST: { struct ltt_ust_session *usess = session->ust_session; + unsigned int chan_count; + assert(usess); - unsigned int chan_count = - lttng_ht_get_count(usess->domain_global.channels); + chan_count = lttng_ht_get_count(usess->domain_global.channels); if (chan_count == 0) { struct lttng_channel *attr; /* Create default channel */ @@ -1109,22 +1682,22 @@ int cmd_add_context(struct ltt_session *session, int domain, } ret = context_ust_add(usess, domain, ctx, channel_name); + free(app_ctx_provider_name); + free(app_ctx_name); + app_ctx_name = NULL; + app_ctx_provider_name = NULL; if (ret != LTTNG_OK) { goto error; } break; } -#if 0 - case LTTNG_DOMAIN_UST_EXEC_NAME: - case LTTNG_DOMAIN_UST_PID: - case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN: -#endif default: ret = LTTNG_ERR_UND; goto error; } - return LTTNG_OK; + ret = LTTNG_OK; + goto end; error: if (chan_kern_created) { @@ -1148,15 +1721,93 @@ error: uchan); trace_ust_destroy_channel(uchan); } +end: + free(app_ctx_provider_name); + free(app_ctx_name); + return ret; +} + +static int validate_event_name(const char *name) +{ + int ret = 0; + const char *c = name; + const char *event_name_end = c + LTTNG_SYMBOL_NAME_LEN; + bool null_terminated = false; + + /* + * Make sure that unescaped wildcards are only used as the last + * character of the event name. + */ + while (c < event_name_end) { + switch (*c) { + case '\0': + null_terminated = true; + goto end; + case '\\': + c++; + break; + case '*': + if ((c + 1) < event_name_end && *(c + 1)) { + /* Wildcard is not the last character */ + ret = LTTNG_ERR_INVALID_EVENT_NAME; + goto end; + } + default: + break; + } + c++; + } +end: + if (!ret && !null_terminated) { + ret = LTTNG_ERR_INVALID_EVENT_NAME; + } + return ret; +} + +static inline bool name_starts_with(const char *name, const char *prefix) +{ + const size_t max_cmp_len = min(strlen(prefix), LTTNG_SYMBOL_NAME_LEN); + + return !strncmp(name, prefix, max_cmp_len); +} + +/* Perform userspace-specific event name validation */ +static int validate_ust_event_name(const char *name) +{ + int ret = 0; + + if (!name) { + ret = -1; + goto end; + } + + /* + * Check name against all internal UST event component namespaces used + * by the agents. + */ + if (name_starts_with(name, DEFAULT_JUL_EVENT_COMPONENT) || + name_starts_with(name, DEFAULT_LOG4J_EVENT_COMPONENT) || + name_starts_with(name, DEFAULT_PYTHON_EVENT_COMPONENT)) { + ret = -1; + } + +end: return ret; } /* - * Command LTTNG_ENABLE_EVENT processed by the client thread. + * Internal version of cmd_enable_event() with a supplemental + * "internal_event" flag which is used to enable internal events which should + * be hidden from clients. Such events are used in the agent implementation to + * enable the events through which all "agent" events are funeled. */ -int cmd_enable_event(struct ltt_session *session, struct lttng_domain *domain, +static int _cmd_enable_event(struct ltt_session *session, + struct lttng_domain *domain, char *channel_name, struct lttng_event *event, - struct lttng_filter_bytecode *filter, int wpipe) + char *filter_expression, + struct lttng_filter_bytecode *filter, + struct lttng_event_exclusion *exclusion, + int wpipe, bool internal_event) { int ret, channel_created = 0; struct lttng_channel *attr; @@ -1165,13 +1816,34 @@ int cmd_enable_event(struct ltt_session *session, struct lttng_domain *domain, assert(event); assert(channel_name); + /* If we have a filter, we must have its filter expression */ + assert(!(!!filter_expression ^ !!filter)); + + DBG("Enable event command for event \'%s\'", event->name); + rcu_read_lock(); + ret = validate_event_name(event->name); + if (ret) { + goto error; + } + switch (domain->type) { case LTTNG_DOMAIN_KERNEL: { struct ltt_kernel_channel *kchan; + /* + * If a non-default channel has been created in the + * session, explicitely require that -c chan_name needs + * to be provided. + */ + if (session->kernel_session->has_non_default_channel + && channel_name[0] == '\0') { + ret = LTTNG_ERR_NEED_CHANNEL_NAME; + goto error; + } + kchan = trace_kernel_get_channel_by_name(channel_name, session->kernel_session); if (kchan == NULL) { @@ -1202,12 +1874,88 @@ int cmd_enable_event(struct ltt_session *session, struct lttng_domain *domain, goto error; } - ret = event_kernel_enable_tracepoint(kchan, event); - if (ret != LTTNG_OK) { - if (channel_created) { - /* Let's not leak a useless channel. */ - kernel_destroy_channel(kchan); + switch (event->type) { + case LTTNG_EVENT_ALL: + { + char *filter_expression_a = NULL; + struct lttng_filter_bytecode *filter_a = NULL; + + /* + * We need to duplicate filter_expression and filter, + * because ownership is passed to first enable + * event. + */ + if (filter_expression) { + filter_expression_a = strdup(filter_expression); + if (!filter_expression_a) { + ret = LTTNG_ERR_FATAL; + goto error; + } + } + if (filter) { + filter_a = zmalloc(sizeof(*filter_a) + filter->len); + if (!filter_a) { + free(filter_expression_a); + ret = LTTNG_ERR_FATAL; + goto error; + } + memcpy(filter_a, filter, sizeof(*filter_a) + filter->len); + } + event->type = LTTNG_EVENT_TRACEPOINT; /* Hack */ + ret = event_kernel_enable_event(kchan, event, + filter_expression, filter); + /* We have passed ownership */ + filter_expression = NULL; + filter = NULL; + if (ret != LTTNG_OK) { + if (channel_created) { + /* Let's not leak a useless channel. */ + kernel_destroy_channel(kchan); + } + free(filter_expression_a); + free(filter_a); + goto error; + } + event->type = LTTNG_EVENT_SYSCALL; /* Hack */ + ret = event_kernel_enable_event(kchan, event, + filter_expression_a, filter_a); + /* We have passed ownership */ + filter_expression_a = NULL; + filter_a = NULL; + if (ret != LTTNG_OK) { + goto error; + } + break; + } + case LTTNG_EVENT_PROBE: + case LTTNG_EVENT_FUNCTION: + case LTTNG_EVENT_FUNCTION_ENTRY: + case LTTNG_EVENT_TRACEPOINT: + ret = event_kernel_enable_event(kchan, event, + filter_expression, filter); + /* We have passed ownership */ + filter_expression = NULL; + filter = NULL; + if (ret != LTTNG_OK) { + if (channel_created) { + /* Let's not leak a useless channel. */ + kernel_destroy_channel(kchan); + } + goto error; + } + break; + case LTTNG_EVENT_SYSCALL: + ret = event_kernel_enable_event(kchan, event, + filter_expression, filter); + /* We have passed ownership */ + filter_expression = NULL; + filter = NULL; + if (ret != LTTNG_OK) { + goto error; } + break; + default: + ret = LTTNG_ERR_UNK; goto error; } @@ -1221,6 +1969,16 @@ int cmd_enable_event(struct ltt_session *session, struct lttng_domain *domain, assert(usess); + /* + * If a non-default channel has been created in the + * session, explicitely require that -c chan_name needs + * to be provided. + */ + if (usess->has_non_default_channel && channel_name[0] == '\0') { + ret = LTTNG_ERR_NEED_CHANNEL_NAME; + goto error; + } + /* Get channel from global UST domain */ uchan = trace_ust_find_channel_by_name(usess->domain_global.channels, channel_name); @@ -1247,169 +2005,161 @@ int cmd_enable_event(struct ltt_session *session, struct lttng_domain *domain, assert(uchan); } - /* At this point, the session and channel exist on the tracer */ - ret = event_ust_enable_tracepoint(usess, uchan, event, filter); - if (ret != LTTNG_OK) { - goto error; - } - break; - } -#if 0 - case LTTNG_DOMAIN_UST_EXEC_NAME: - case LTTNG_DOMAIN_UST_PID: - case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN: -#endif - default: - ret = LTTNG_ERR_UND; - goto error; - } - - ret = LTTNG_OK; - -error: - rcu_read_unlock(); - return ret; -} - -/* - * Command LTTNG_ENABLE_ALL_EVENT processed by the client thread. - */ -int cmd_enable_event_all(struct ltt_session *session, - struct lttng_domain *domain, char *channel_name, int event_type, - struct lttng_filter_bytecode *filter, int wpipe) -{ - int ret; - struct lttng_channel *attr; - - assert(session); - assert(channel_name); - - rcu_read_lock(); - - switch (domain->type) { - case LTTNG_DOMAIN_KERNEL: - { - struct ltt_kernel_channel *kchan; - - assert(session->kernel_session); - - kchan = trace_kernel_get_channel_by_name(channel_name, - session->kernel_session); - if (kchan == NULL) { - /* Create default channel */ - attr = channel_new_default_attr(LTTNG_DOMAIN_KERNEL, - LTTNG_BUFFER_GLOBAL); - if (attr == NULL) { - ret = LTTNG_ERR_FATAL; - goto error; - } - strncpy(attr->name, channel_name, sizeof(attr->name)); - - ret = cmd_enable_channel(session, domain, attr, wpipe); - if (ret != LTTNG_OK) { - free(attr); - goto error; - } - free(attr); - - /* Get the newly created kernel channel pointer */ - kchan = trace_kernel_get_channel_by_name(channel_name, - session->kernel_session); - assert(kchan); - } - - switch (event_type) { - case LTTNG_EVENT_SYSCALL: - ret = event_kernel_enable_all_syscalls(kchan, kernel_tracer_fd); - break; - case LTTNG_EVENT_TRACEPOINT: - /* - * This call enables all LTTNG_KERNEL_TRACEPOINTS and - * events already registered to the channel. - */ - ret = event_kernel_enable_all_tracepoints(kchan, kernel_tracer_fd); - break; - case LTTNG_EVENT_ALL: - /* Enable syscalls and tracepoints */ - ret = event_kernel_enable_all(kchan, kernel_tracer_fd); - break; - default: - ret = LTTNG_ERR_KERN_ENABLE_FAIL; - goto error; - } - - /* Manage return value */ - if (ret != LTTNG_OK) { + if (uchan->domain != LTTNG_DOMAIN_UST && !internal_event) { /* - * On error, cmd_enable_channel call will take care of destroying - * the created channel if it was needed. + * Don't allow users to add UST events to channels which + * are assigned to a userspace subdomain (JUL, Log4J, + * Python, etc.). */ + ret = LTTNG_ERR_INVALID_CHANNEL_DOMAIN; goto error; } - kernel_wait_quiescent(kernel_tracer_fd); - break; - } - case LTTNG_DOMAIN_UST: - { - struct ltt_ust_channel *uchan; - struct ltt_ust_session *usess = session->ust_session; - - assert(usess); - - /* Get channel from global UST domain */ - uchan = trace_ust_find_channel_by_name(usess->domain_global.channels, - channel_name); - if (uchan == NULL) { - /* Create default channel */ - attr = channel_new_default_attr(LTTNG_DOMAIN_UST, - usess->buffer_type); - if (attr == NULL) { - ret = LTTNG_ERR_FATAL; - goto error; - } - strncpy(attr->name, channel_name, sizeof(attr->name)); - - ret = cmd_enable_channel(session, domain, attr, wpipe); - if (ret != LTTNG_OK) { - free(attr); + if (!internal_event) { + /* + * Ensure the event name is not reserved for internal + * use. + */ + ret = validate_ust_event_name(event->name); + if (ret) { + WARN("Userspace event name %s failed validation.", + event->name ? + event->name : "NULL"); + ret = LTTNG_ERR_INVALID_EVENT_NAME; goto error; } - free(attr); - - /* Get the newly created channel reference back */ - uchan = trace_ust_find_channel_by_name( - usess->domain_global.channels, channel_name); - assert(uchan); } /* At this point, the session and channel exist on the tracer */ + ret = event_ust_enable_tracepoint(usess, uchan, event, + filter_expression, filter, exclusion, + internal_event); + /* We have passed ownership */ + filter_expression = NULL; + filter = NULL; + exclusion = NULL; + if (ret == LTTNG_ERR_UST_EVENT_ENABLED) { + goto already_enabled; + } else if (ret != LTTNG_OK) { + goto error; + } + break; + } + case LTTNG_DOMAIN_LOG4J: + case LTTNG_DOMAIN_JUL: + case LTTNG_DOMAIN_PYTHON: + { + const char *default_event_name, *default_chan_name; + struct agent *agt; + struct lttng_event uevent; + struct lttng_domain tmp_dom; + struct ltt_ust_session *usess = session->ust_session; - switch (event_type) { - case LTTNG_EVENT_ALL: - case LTTNG_EVENT_TRACEPOINT: - ret = event_ust_enable_all_tracepoints(usess, uchan, filter); - if (ret != LTTNG_OK) { + assert(usess); + + agt = trace_ust_find_agent(usess, domain->type); + if (!agt) { + agt = agent_create(domain->type); + if (!agt) { + ret = LTTNG_ERR_NOMEM; goto error; } + agent_add(agt, usess->agents); + } + + /* Create the default tracepoint. */ + memset(&uevent, 0, sizeof(uevent)); + uevent.type = LTTNG_EVENT_TRACEPOINT; + uevent.loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL; + default_event_name = event_get_default_agent_ust_name( + domain->type); + if (!default_event_name) { + ret = LTTNG_ERR_FATAL; + goto error; + } + strncpy(uevent.name, default_event_name, sizeof(uevent.name)); + uevent.name[sizeof(uevent.name) - 1] = '\0'; + + /* + * The domain type is changed because we are about to enable the + * default channel and event for the JUL domain that are hardcoded. + * This happens in the UST domain. + */ + memcpy(&tmp_dom, domain, sizeof(tmp_dom)); + tmp_dom.type = LTTNG_DOMAIN_UST; + + switch (domain->type) { + case LTTNG_DOMAIN_LOG4J: + default_chan_name = DEFAULT_LOG4J_CHANNEL_NAME; + break; + case LTTNG_DOMAIN_JUL: + default_chan_name = DEFAULT_JUL_CHANNEL_NAME; + break; + case LTTNG_DOMAIN_PYTHON: + default_chan_name = DEFAULT_PYTHON_CHANNEL_NAME; break; default: - ret = LTTNG_ERR_UST_ENABLE_FAIL; + /* The switch/case we are in makes this impossible */ + assert(0); + } + + { + char *filter_expression_copy = NULL; + struct lttng_filter_bytecode *filter_copy = NULL; + + if (filter) { + const size_t filter_size = sizeof( + struct lttng_filter_bytecode) + + filter->len; + + filter_copy = zmalloc(filter_size); + if (!filter_copy) { + ret = LTTNG_ERR_NOMEM; + goto error; + } + memcpy(filter_copy, filter, filter_size); + + filter_expression_copy = + strdup(filter_expression); + if (!filter_expression) { + ret = LTTNG_ERR_NOMEM; + } + + if (!filter_expression_copy || !filter_copy) { + free(filter_expression_copy); + free(filter_copy); + goto error; + } + } + + ret = cmd_enable_event_internal(session, &tmp_dom, + (char *) default_chan_name, + &uevent, filter_expression_copy, + filter_copy, NULL, wpipe); + } + + if (ret == LTTNG_ERR_UST_EVENT_ENABLED) { + goto already_enabled; + } else if (ret != LTTNG_OK) { goto error; } - /* Manage return value */ + /* The wild card * means that everything should be enabled. */ + if (strncmp(event->name, "*", 1) == 0 && strlen(event->name) == 1) { + ret = event_agent_enable_all(usess, agt, event, filter, + filter_expression); + } else { + ret = event_agent_enable(usess, agt, event, filter, + filter_expression); + } + filter = NULL; + filter_expression = NULL; if (ret != LTTNG_OK) { goto error; } break; } -#if 0 - case LTTNG_DOMAIN_UST_EXEC_NAME: - case LTTNG_DOMAIN_UST_PID: - case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN: -#endif default: ret = LTTNG_ERR_UND; goto error; @@ -1417,16 +2167,52 @@ int cmd_enable_event_all(struct ltt_session *session, ret = LTTNG_OK; +already_enabled: error: + free(filter_expression); + free(filter); + free(exclusion); rcu_read_unlock(); return ret; } +/* + * Command LTTNG_ENABLE_EVENT processed by the client thread. + * We own filter, exclusion, and filter_expression. + */ +int cmd_enable_event(struct ltt_session *session, struct lttng_domain *domain, + char *channel_name, struct lttng_event *event, + char *filter_expression, + struct lttng_filter_bytecode *filter, + struct lttng_event_exclusion *exclusion, + int wpipe) +{ + return _cmd_enable_event(session, domain, channel_name, event, + filter_expression, filter, exclusion, wpipe, false); +} + +/* + * Enable an event which is internal to LTTng. An internal should + * never be made visible to clients and are immune to checks such as + * reserved names. + */ +static int cmd_enable_event_internal(struct ltt_session *session, + struct lttng_domain *domain, + char *channel_name, struct lttng_event *event, + char *filter_expression, + struct lttng_filter_bytecode *filter, + struct lttng_event_exclusion *exclusion, + int wpipe) +{ + return _cmd_enable_event(session, domain, channel_name, event, + filter_expression, filter, exclusion, wpipe, true); +} /* * Command LTTNG_LIST_TRACEPOINTS processed by the client thread. */ -ssize_t cmd_list_tracepoints(int domain, struct lttng_event **events) +ssize_t cmd_list_tracepoints(enum lttng_domain_type domain, + struct lttng_event **events) { int ret; ssize_t nb_events = 0; @@ -1446,6 +2232,15 @@ ssize_t cmd_list_tracepoints(int domain, struct lttng_event **events) goto error; } break; + case LTTNG_DOMAIN_LOG4J: + case LTTNG_DOMAIN_JUL: + case LTTNG_DOMAIN_PYTHON: + nb_events = agent_list_events(events, domain); + if (nb_events < 0) { + ret = LTTNG_ERR_UST_LIST_FAIL; + goto error; + } + break; default: ret = LTTNG_ERR_UND; goto error; @@ -1461,7 +2256,7 @@ error: /* * Command LTTNG_LIST_TRACEPOINT_FIELDS processed by the client thread. */ -ssize_t cmd_list_tracepoint_fields(int domain, +ssize_t cmd_list_tracepoint_fields(enum lttng_domain_type domain, struct lttng_event_field **fields) { int ret; @@ -1488,12 +2283,71 @@ error: return -ret; } +ssize_t cmd_list_syscalls(struct lttng_event **events) +{ + return syscall_table_list(events); +} + +/* + * Command LTTNG_LIST_TRACKER_PIDS processed by the client thread. + * + * Called with session lock held. + */ +ssize_t cmd_list_tracker_pids(struct ltt_session *session, + enum lttng_domain_type domain, int32_t **pids) +{ + int ret; + ssize_t nr_pids = 0; + + switch (domain) { + case LTTNG_DOMAIN_KERNEL: + { + struct ltt_kernel_session *ksess; + + ksess = session->kernel_session; + nr_pids = kernel_list_tracker_pids(ksess, pids); + if (nr_pids < 0) { + ret = LTTNG_ERR_KERN_LIST_FAIL; + goto error; + } + break; + } + case LTTNG_DOMAIN_UST: + { + struct ltt_ust_session *usess; + + usess = session->ust_session; + nr_pids = trace_ust_list_tracker_pids(usess, pids); + if (nr_pids < 0) { + ret = LTTNG_ERR_UST_LIST_FAIL; + goto error; + } + break; + } + case LTTNG_DOMAIN_LOG4J: + case LTTNG_DOMAIN_JUL: + case LTTNG_DOMAIN_PYTHON: + default: + ret = LTTNG_ERR_UND; + goto error; + } + + return nr_pids; + +error: + /* Return negative value to differentiate return code */ + return -ret; +} + /* * Command LTTNG_START_TRACE processed by the client thread. + * + * Called with session mutex held. */ int cmd_start_trace(struct ltt_session *session) { int ret; + unsigned long nb_chan = 0; struct ltt_kernel_session *ksession; struct ltt_ust_session *usess; @@ -1503,13 +2357,26 @@ int cmd_start_trace(struct ltt_session *session) ksession = session->kernel_session; usess = session->ust_session; - if (session->enabled) { - /* Already started. */ + /* Is the session already started? */ + if (session->active) { ret = LTTNG_ERR_TRACE_ALREADY_STARTED; goto error; } - session->enabled = 1; + /* + * Starting a session without channel is useless since after that it's not + * possible to enable channel thus inform the client. + */ + if (usess && usess->domain_global.channels) { + nb_chan += lttng_ht_get_count(usess->domain_global.channels); + } + if (ksession) { + nb_chan += ksession->channel_count; + } + if (!nb_chan) { + ret = LTTNG_ERR_NO_CHANNEL; + goto error; + } /* Kernel tracing */ if (ksession != NULL) { @@ -1521,7 +2388,11 @@ int cmd_start_trace(struct ltt_session *session) /* Flag session that trace should start automatically */ if (usess) { - usess->start_trace = 1; + /* + * Even though the start trace might fail, flag this session active so + * other application coming in are started by default. + */ + usess->active = 1; ret = ust_app_start_trace_all(usess); if (ret < 0) { @@ -1530,7 +2401,9 @@ int cmd_start_trace(struct ltt_session *session) } } - session->started = 1; + /* Flag this after a successful start. */ + session->has_been_started = 1; + session->active = 1; ret = LTTNG_OK; @@ -1554,15 +2427,14 @@ int cmd_stop_trace(struct ltt_session *session) ksession = session->kernel_session; usess = session->ust_session; - if (!session->enabled) { + /* Session is not active. Skip everythong and inform the client. */ + if (!session->active) { ret = LTTNG_ERR_TRACE_ALREADY_STOPPED; goto error; } - session->enabled = 0; - /* Kernel tracer */ - if (ksession && ksession->started) { + if (ksession && ksession->active) { DBG("Stop kernel tracing"); /* Flush metadata if exist */ @@ -1589,11 +2461,15 @@ int cmd_stop_trace(struct ltt_session *session) kernel_wait_quiescent(kernel_tracer_fd); - ksession->started = 0; + ksession->active = 0; } - if (usess && usess->start_trace) { - usess->start_trace = 0; + if (usess && usess->active) { + /* + * Even though the stop trace might fail, flag this session inactive so + * other application coming in are not started by default. + */ + usess->active = 0; ret = ust_app_stop_trace_all(usess); if (ret < 0) { @@ -1602,6 +2478,8 @@ int cmd_stop_trace(struct ltt_session *session) } } + /* Flag inactive after a successful stop. */ + session->active = 0; ret = LTTNG_OK; error: @@ -1611,59 +2489,71 @@ error: /* * Command LTTNG_SET_CONSUMER_URI processed by the client thread. */ -int cmd_set_consumer_uri(int domain, struct ltt_session *session, - size_t nb_uri, struct lttng_uri *uris) +int cmd_set_consumer_uri(struct ltt_session *session, size_t nb_uri, + struct lttng_uri *uris) { int ret, i; struct ltt_kernel_session *ksess = session->kernel_session; struct ltt_ust_session *usess = session->ust_session; - struct consumer_output *consumer = NULL; assert(session); assert(uris); assert(nb_uri > 0); - /* Can't enable consumer after session started. */ - if (session->enabled) { + /* Can't set consumer URI if the session is active. */ + if (session->active) { ret = LTTNG_ERR_TRACE_ALREADY_STARTED; goto error; } - /* - * This case switch makes sure the domain session has a temporary consumer - * so the URL can be set. - */ - switch (domain) { - case 0: - /* Code flow error. A session MUST always have a consumer object */ - assert(session->consumer); - /* - * The URL will be added to the tracing session consumer instead of a - * specific domain consumer. - */ - consumer = session->consumer; - break; - case LTTNG_DOMAIN_KERNEL: - /* Code flow error if we don't have a kernel session here. */ - assert(ksess); - assert(ksess->consumer); - consumer = ksess->consumer; - break; - case LTTNG_DOMAIN_UST: - /* Code flow error if we don't have a kernel session here. */ - assert(usess); - assert(usess->consumer); - consumer = usess->consumer; - break; - } - + /* Set the "global" consumer URIs */ for (i = 0; i < nb_uri; i++) { - ret = add_uri_to_consumer(consumer, &uris[i], domain, session->name); + ret = add_uri_to_consumer(session->consumer, + &uris[i], 0, session->name); if (ret != LTTNG_OK) { goto error; } } + /* Set UST session URIs */ + if (session->ust_session) { + for (i = 0; i < nb_uri; i++) { + ret = add_uri_to_consumer( + session->ust_session->consumer, + &uris[i], LTTNG_DOMAIN_UST, + session->name); + if (ret != LTTNG_OK) { + goto error; + } + } + } + + /* Set kernel session URIs */ + if (session->kernel_session) { + for (i = 0; i < nb_uri; i++) { + ret = add_uri_to_consumer( + session->kernel_session->consumer, + &uris[i], LTTNG_DOMAIN_KERNEL, + session->name); + if (ret != LTTNG_OK) { + goto error; + } + } + } + + /* + * Make sure to set the session in output mode after we set URI since a + * session can be created without URL (thus flagged in no output mode). + */ + session->output_traces = 1; + if (ksess) { + ksess->output_traces = 1; + } + + if (usess) { + usess->output_traces = 1; + } + /* All good! */ ret = LTTNG_OK; @@ -1675,7 +2565,7 @@ error: * Command LTTNG_CREATE_SESSION processed by the client thread. */ int cmd_create_session_uri(char *name, struct lttng_uri *uris, - size_t nb_uri, lttng_sock_cred *creds) + size_t nb_uri, lttng_sock_cred *creds, unsigned int live_timer) { int ret; struct ltt_session *session; @@ -1713,6 +2603,7 @@ int cmd_create_session_uri(char *name, struct lttng_uri *uris, session = session_find_by_name(name); assert(session); + session->live_timer = live_timer; /* Create default consumer output for the session not yet created. */ session->consumer = consumer_create_output(CONSUMER_DST_LOCAL); if (session->consumer == NULL) { @@ -1721,7 +2612,7 @@ int cmd_create_session_uri(char *name, struct lttng_uri *uris, } if (uris) { - ret = cmd_set_consumer_uri(0, session, nb_uri, uris); + ret = cmd_set_consumer_uri(session, nb_uri, uris); if (ret != LTTNG_OK) { goto consumer_error; } @@ -1742,8 +2633,76 @@ find_error: return ret; } +/* + * Command LTTNG_CREATE_SESSION_SNAPSHOT processed by the client thread. + */ +int cmd_create_session_snapshot(char *name, struct lttng_uri *uris, + size_t nb_uri, lttng_sock_cred *creds) +{ + int ret; + struct ltt_session *session; + struct snapshot_output *new_output = NULL; + + assert(name); + assert(creds); + + /* + * Create session in no output mode with URIs set to NULL. The uris we've + * received are for a default snapshot output if one. + */ + ret = cmd_create_session_uri(name, NULL, 0, creds, 0); + if (ret != LTTNG_OK) { + goto error; + } + + /* Get the newly created session pointer back. This should NEVER fail. */ + session = session_find_by_name(name); + assert(session); + + /* Flag session for snapshot mode. */ + session->snapshot_mode = 1; + + /* Skip snapshot output creation if no URI is given. */ + if (nb_uri == 0) { + goto end; + } + + new_output = snapshot_output_alloc(); + if (!new_output) { + ret = LTTNG_ERR_NOMEM; + goto error_snapshot_alloc; + } + + ret = snapshot_output_init_with_uri(DEFAULT_SNAPSHOT_MAX_SIZE, NULL, + uris, nb_uri, session->consumer, new_output, &session->snapshot); + if (ret < 0) { + if (ret == -ENOMEM) { + ret = LTTNG_ERR_NOMEM; + } else { + ret = LTTNG_ERR_INVALID; + } + goto error_snapshot; + } + + rcu_read_lock(); + snapshot_add_output(&session->snapshot, new_output); + rcu_read_unlock(); + +end: + return LTTNG_OK; + +error_snapshot: + snapshot_output_destroy(new_output); +error_snapshot_alloc: + session_destroy(session); +error: + return ret; +} + /* * Command LTTNG_DESTROY_SESSION processed by the client thread. + * + * Called with session lock held. */ int cmd_destroy_session(struct ltt_session *session, int wpipe) { @@ -1792,7 +2751,8 @@ int cmd_destroy_session(struct ltt_session *session, int wpipe) /* * Command LTTNG_CALIBRATE processed by the client thread. */ -int cmd_calibrate(int domain, struct lttng_calibrate *calibrate) +int cmd_calibrate(enum lttng_domain_type domain, + struct lttng_calibrate *calibrate) { int ret; @@ -1801,7 +2761,14 @@ int cmd_calibrate(int domain, struct lttng_calibrate *calibrate) { struct lttng_kernel_calibrate kcalibrate; - kcalibrate.type = calibrate->type; + switch (calibrate->type) { + case LTTNG_CALIBRATE_FUNCTION: + default: + /* Default and only possible calibrate option. */ + kcalibrate.type = LTTNG_KERNEL_CALIBRATE_KRETPROBE; + break; + } + ret = kernel_calibrate(kernel_tracer_fd, &kcalibrate); if (ret < 0) { ret = LTTNG_ERR_KERN_ENABLE_FAIL; @@ -1813,7 +2780,14 @@ int cmd_calibrate(int domain, struct lttng_calibrate *calibrate) { struct lttng_ust_calibrate ucalibrate; - ucalibrate.type = calibrate->type; + switch (calibrate->type) { + case LTTNG_CALIBRATE_FUNCTION: + default: + /* Default and only possible calibrate option. */ + ucalibrate.type = LTTNG_UST_CALIBRATE_TRACEPOINT; + break; + } + ret = ust_app_calibrate_glb(&ucalibrate); if (ret < 0) { ret = LTTNG_ERR_UST_CALIBRATE_FAIL; @@ -1835,8 +2809,9 @@ error: /* * Command LTTNG_REGISTER_CONSUMER processed by the client thread. */ -int cmd_register_consumer(struct ltt_session *session, int domain, - const char *sock_path, struct consumer_data *cdata) +int cmd_register_consumer(struct ltt_session *session, + enum lttng_domain_type domain, const char *sock_path, + struct consumer_data *cdata) { int ret, sock; struct consumer_socket *socket = NULL; @@ -1863,13 +2838,15 @@ int cmd_register_consumer(struct ltt_session *session, int domain, ret = LTTNG_ERR_CONNECT_FAIL; goto error; } + cdata->cmd_sock = sock; - socket = consumer_allocate_socket(sock); + socket = consumer_allocate_socket(&cdata->cmd_sock); if (socket == NULL) { ret = close(sock); if (ret < 0) { PERROR("close register consumer"); } + cdata->cmd_sock = -1; ret = LTTNG_ERR_FATAL; goto error; } @@ -1916,6 +2893,8 @@ ssize_t cmd_list_domains(struct ltt_session *session, { int ret, index = 0; ssize_t nb_dom = 0; + struct agent *agt; + struct lttng_ht_iter iter; if (session->kernel_session != NULL) { DBG3("Listing domains found kernel domain"); @@ -1925,6 +2904,19 @@ ssize_t cmd_list_domains(struct ltt_session *session, if (session->ust_session != NULL) { DBG3("Listing domains found UST global domain"); nb_dom++; + + rcu_read_lock(); + cds_lfht_for_each_entry(session->ust_session->agents->ht, &iter.iter, + agt, node.node) { + if (agt->being_used) { + nb_dom++; + } + } + rcu_read_unlock(); + } + + if (!nb_dom) { + goto end; } *domains = zmalloc(nb_dom * sizeof(struct lttng_domain)); @@ -1935,6 +2927,10 @@ ssize_t cmd_list_domains(struct ltt_session *session, if (session->kernel_session != NULL) { (*domains)[index].type = LTTNG_DOMAIN_KERNEL; + + /* Kernel session buffer type is always GLOBAL */ + (*domains)[index].buf_type = LTTNG_BUFFER_GLOBAL; + index++; } @@ -1942,8 +2938,19 @@ ssize_t cmd_list_domains(struct ltt_session *session, (*domains)[index].type = LTTNG_DOMAIN_UST; (*domains)[index].buf_type = session->ust_session->buffer_type; index++; - } + rcu_read_lock(); + cds_lfht_for_each_entry(session->ust_session->agents->ht, &iter.iter, + agt, node.node) { + if (agt->being_used) { + (*domains)[index].type = agt->domain; + (*domains)[index].buf_type = session->ust_session->buffer_type; + index++; + } + } + rcu_read_unlock(); + } +end: return nb_dom; error: @@ -1955,11 +2962,10 @@ error: /* * Command LTTNG_LIST_CHANNELS processed by the client thread. */ -ssize_t cmd_list_channels(int domain, struct ltt_session *session, - struct lttng_channel **channels) +ssize_t cmd_list_channels(enum lttng_domain_type domain, + struct ltt_session *session, struct lttng_channel **channels) { - int ret; - ssize_t nb_chan = 0; + ssize_t nb_chan = 0, payload_size = 0, ret; switch (domain) { case LTTNG_DOMAIN_KERNEL: @@ -1968,51 +2974,58 @@ ssize_t cmd_list_channels(int domain, struct ltt_session *session, } DBG3("Number of kernel channels %zd", nb_chan); if (nb_chan <= 0) { - ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND; + ret = -LTTNG_ERR_KERN_CHAN_NOT_FOUND; + goto end; } break; case LTTNG_DOMAIN_UST: if (session->ust_session != NULL) { + rcu_read_lock(); nb_chan = lttng_ht_get_count( - session->ust_session->domain_global.channels); + session->ust_session->domain_global.channels); + rcu_read_unlock(); } DBG3("Number of UST global channels %zd", nb_chan); - if (nb_chan <= 0) { - ret = LTTNG_ERR_UST_CHAN_NOT_FOUND; + if (nb_chan < 0) { + ret = -LTTNG_ERR_UST_CHAN_NOT_FOUND; + goto end; } break; default: - *channels = NULL; - ret = LTTNG_ERR_UND; - goto error; + ret = -LTTNG_ERR_UND; + goto end; } if (nb_chan > 0) { - *channels = zmalloc(nb_chan * sizeof(struct lttng_channel)); + const size_t channel_size = sizeof(struct lttng_channel) + + sizeof(struct lttcomm_channel_extended); + struct lttcomm_channel_extended *channel_exts; + + payload_size = nb_chan * channel_size; + *channels = zmalloc(payload_size); if (*channels == NULL) { - ret = LTTNG_ERR_FATAL; - goto error; + ret = -LTTNG_ERR_FATAL; + goto end; } - list_lttng_channels(domain, session, *channels); + channel_exts = ((void *) *channels) + + (nb_chan * sizeof(struct lttng_channel)); + list_lttng_channels(domain, session, *channels, channel_exts); } else { *channels = NULL; - /* Ret value was set in the domain switch case */ - goto error; } - return nb_chan; - -error: - /* Return negative value to differentiate return code */ - return -ret; + ret = payload_size; +end: + return ret; } /* * Command LTTNG_LIST_EVENTS processed by the client thread. */ -ssize_t cmd_list_events(int domain, struct ltt_session *session, - char *channel_name, struct lttng_event **events) +ssize_t cmd_list_events(enum lttng_domain_type domain, + struct ltt_session *session, char *channel_name, + struct lttng_event **events, size_t *total_size) { int ret = 0; ssize_t nb_event = 0; @@ -2021,17 +3034,39 @@ ssize_t cmd_list_events(int domain, struct ltt_session *session, case LTTNG_DOMAIN_KERNEL: if (session->kernel_session != NULL) { nb_event = list_lttng_kernel_events(channel_name, - session->kernel_session, events); + session->kernel_session, events, + total_size); } break; case LTTNG_DOMAIN_UST: { if (session->ust_session != NULL) { nb_event = list_lttng_ust_global_events(channel_name, - &session->ust_session->domain_global, events); + &session->ust_session->domain_global, events, + total_size); + } + break; + } + case LTTNG_DOMAIN_LOG4J: + case LTTNG_DOMAIN_JUL: + case LTTNG_DOMAIN_PYTHON: + if (session->ust_session) { + struct lttng_ht_iter iter; + struct agent *agt; + + rcu_read_lock(); + cds_lfht_for_each_entry(session->ust_session->agents->ht, + &iter.iter, agt, node.node) { + if (agt->domain == domain) { + nb_event = list_lttng_agent_events( + agt, events, + total_size); + break; + } + } + rcu_read_unlock(); } break; - } default: ret = LTTNG_ERR_UND; goto error; @@ -2092,14 +3127,16 @@ void cmd_list_lttng_sessions(struct lttng_session *sessions, uid_t uid, strncpy(sessions[i].name, session->name, NAME_MAX); sessions[i].name[NAME_MAX - 1] = '\0'; - sessions[i].enabled = session->enabled; + sessions[i].enabled = session->active; + sessions[i].snapshot_mode = session->snapshot_mode; + sessions[i].live_timer_interval = session->live_timer; i++; } } /* * Command LTTNG_DATA_PENDING returning 0 if the data is NOT pending meaning - * ready for trace analysis (or anykind of reader) or else 1 for pending data. + * ready for trace analysis (or any kind of reader) or else 1 for pending data. */ int cmd_data_pending(struct ltt_session *session) { @@ -2110,9 +3147,24 @@ int cmd_data_pending(struct ltt_session *session) assert(session); /* Session MUST be stopped to ask for data availability. */ - if (session->enabled) { + if (session->active) { ret = LTTNG_ERR_SESSION_STARTED; goto error; + } else { + /* + * If stopped, just make sure we've started before else the above call + * will always send that there is data pending. + * + * The consumer assumes that when the data pending command is received, + * the trace has been started before or else no output data is written + * by the streams which is a condition for data pending. So, this is + * *VERY* important that we don't ask the consumer before a start + * trace. + */ + if (!session->has_been_started) { + ret = 0; + goto error; + } } if (ksess && ksess->consumer) { @@ -2155,8 +3207,8 @@ int cmd_snapshot_add_output(struct ltt_session *session, DBG("Cmd snapshot add output for session %s", session->name); /* - * Persmission denied to create an output if the session is not set in no - * output mode. + * Permission denied to create an output if the session is not + * set in no output mode. */ if (session->output_traces) { ret = LTTNG_ERR_EPERM; @@ -2187,27 +3239,6 @@ int cmd_snapshot_add_output(struct ltt_session *session, goto free_error; } - /* - * Copy sockets so the snapshot output can use them on destroy. - */ - - if (session->ust_session) { - ret = consumer_copy_sockets(new_output->consumer, - session->ust_session->consumer); - if (ret < 0) { - goto free_error; - } - new_output->ust_sockets_copied = 1; - } - if (session->kernel_session) { - ret = consumer_copy_sockets(new_output->consumer, - session->kernel_session->consumer); - if (ret < 0) { - goto free_error; - } - new_output->kernel_sockets_copied = 1; - } - rcu_read_lock(); snapshot_add_output(&session->snapshot, new_output); if (id) { @@ -2232,26 +3263,31 @@ int cmd_snapshot_del_output(struct ltt_session *session, struct lttng_snapshot_output *output) { int ret; - struct snapshot_output *sout; + struct snapshot_output *sout = NULL; assert(session); assert(output); - DBG("Cmd snapshot del output id %" PRIu32 " for session %s", output->id, - session->name); - rcu_read_lock(); /* - * Persmission denied to create an output if the session is not set in no - * output mode. + * Permission denied to create an output if the session is not + * set in no output mode. */ if (session->output_traces) { ret = LTTNG_ERR_EPERM; goto error; } - sout = snapshot_find_output_by_id(output->id, &session->snapshot); + if (output->id) { + DBG("Cmd snapshot del output id %" PRIu32 " for session %s", output->id, + session->name); + sout = snapshot_find_output_by_id(output->id, &session->snapshot); + } else if (*output->name != '\0') { + DBG("Cmd snapshot del output name %s for session %s", output->name, + session->name); + sout = snapshot_find_output_by_name(output->name, &session->snapshot); + } if (!sout) { ret = LTTNG_ERR_INVALID; goto error; @@ -2277,7 +3313,7 @@ ssize_t cmd_snapshot_list_outputs(struct ltt_session *session, struct lttng_snapshot_output **outputs) { int ret, idx = 0; - struct lttng_snapshot_output *list; + struct lttng_snapshot_output *list = NULL; struct lttng_ht_iter iter; struct snapshot_output *output; @@ -2287,11 +3323,11 @@ ssize_t cmd_snapshot_list_outputs(struct ltt_session *session, DBG("Cmd snapshot list outputs for session %s", session->name); /* - * Persmission denied to create an output if the session is not set in no - * output mode. + * Permission denied to create an output if the session is not + * set in no output mode. */ if (session->output_traces) { - ret = LTTNG_ERR_EPERM; + ret = -LTTNG_ERR_EPERM; goto error; } @@ -2302,11 +3338,12 @@ ssize_t cmd_snapshot_list_outputs(struct ltt_session *session, list = zmalloc(session->snapshot.nb_output * sizeof(*list)); if (!list) { - ret = LTTNG_ERR_NOMEM; + ret = -LTTNG_ERR_NOMEM; goto error; } /* Copy list from session to the new list object. */ + rcu_read_lock(); cds_lfht_for_each_entry(session->snapshot.output_ht->ht, &iter.iter, output, node.node) { assert(output->consumer); @@ -2321,40 +3358,190 @@ ssize_t cmd_snapshot_list_outputs(struct ltt_session *session, ret = uri_to_str_url(&output->consumer->dst.net.control, list[idx].ctrl_url, sizeof(list[idx].ctrl_url)); if (ret < 0) { - ret = LTTNG_ERR_NOMEM; - goto free_error; + ret = -LTTNG_ERR_NOMEM; + goto error; } /* Data URI. */ ret = uri_to_str_url(&output->consumer->dst.net.data, list[idx].data_url, sizeof(list[idx].data_url)); if (ret < 0) { - ret = LTTNG_ERR_NOMEM; - goto free_error; + ret = -LTTNG_ERR_NOMEM; + goto error; } } idx++; } *outputs = list; - return session->snapshot.nb_output; - -free_error: - free(list); + list = NULL; + ret = session->snapshot.nb_output; error: - return -ret; + free(list); + rcu_read_unlock(); + return ret; +} + +/* + * Check if we can regenerate the metadata for this session. + * Only kernel, UST per-uid and non-live sessions are supported. + * + * Return 0 if the metadata can be generated, a LTTNG_ERR code otherwise. + */ +static +int check_metadata_regenerate_support(struct ltt_session *session) +{ + int ret; + + assert(session); + + if (session->live_timer != 0) { + ret = LTTNG_ERR_LIVE_SESSION; + goto end; + } + if (!session->active) { + ret = LTTNG_ERR_SESSION_NOT_STARTED; + goto end; + } + if (session->ust_session) { + switch (session->ust_session->buffer_type) { + case LTTNG_BUFFER_PER_UID: + break; + case LTTNG_BUFFER_PER_PID: + ret = LTTNG_ERR_PER_PID_SESSION; + goto end; + default: + assert(0); + ret = LTTNG_ERR_UNK; + goto end; + } + } + if (session->consumer->type == CONSUMER_DST_NET && + session->consumer->relay_minor_version < 8) { + ret = LTTNG_ERR_RELAYD_VERSION_FAIL; + goto end; + } + ret = 0; + +end: + return ret; +} + +static +int ust_metadata_regenerate(struct ltt_ust_session *usess) +{ + int ret = 0; + struct buffer_reg_uid *uid_reg = NULL; + struct buffer_reg_session *session_reg = NULL; + + rcu_read_lock(); + cds_list_for_each_entry(uid_reg, &usess->buffer_reg_uid_list, lnode) { + struct ust_registry_session *registry; + struct ust_registry_channel *chan; + struct lttng_ht_iter iter_chan; + + session_reg = uid_reg->registry; + registry = session_reg->reg.ust; + + pthread_mutex_lock(®istry->lock); + registry->metadata_len_sent = 0; + memset(registry->metadata, 0, registry->metadata_alloc_len); + registry->metadata_len = 0; + registry->metadata_version++; + ret = ust_metadata_session_statedump(registry, NULL, + registry->major, registry->minor); + if (ret) { + pthread_mutex_unlock(®istry->lock); + ERR("Failed to generate session metadata (err = %d)", + ret); + goto end; + } + cds_lfht_for_each_entry(registry->channels->ht, &iter_chan.iter, + chan, node.node) { + struct ust_registry_event *event; + struct lttng_ht_iter iter_event; + + ret = ust_metadata_channel_statedump(registry, chan); + if (ret) { + pthread_mutex_unlock(®istry->lock); + ERR("Failed to generate channel metadata " + "(err = %d)", ret); + goto end; + } + cds_lfht_for_each_entry(chan->ht->ht, &iter_event.iter, + event, node.node) { + ret = ust_metadata_event_statedump(registry, + chan, event); + if (ret) { + pthread_mutex_unlock(®istry->lock); + ERR("Failed to generate event metadata " + "(err = %d)", ret); + goto end; + } + } + } + pthread_mutex_unlock(®istry->lock); + } + +end: + rcu_read_unlock(); + return ret; +} + +/* + * Command LTTNG_METADATA_REGENERATE from the lttng-ctl library. + * + * Ask the consumer to truncate the existing metadata file(s) and + * then regenerate the metadata. Live and per-pid sessions are not + * supported and return an error. + * + * Return 0 on success or else a LTTNG_ERR code. + */ +int cmd_metadata_regenerate(struct ltt_session *session) +{ + int ret; + + assert(session); + + ret = check_metadata_regenerate_support(session); + if (ret) { + goto end; + } + + if (session->kernel_session) { + ret = kernctl_session_metadata_regenerate( + session->kernel_session->fd); + if (ret < 0) { + ERR("Failed to regenerate the kernel metadata"); + goto end; + } + } + + if (session->ust_session) { + ret = ust_metadata_regenerate(session->ust_session); + if (ret < 0) { + ERR("Failed to regenerate the UST metadata"); + goto end; + } + } + DBG("Cmd metadata regenerate for session %s", session->name); + ret = LTTNG_OK; + +end: + return ret; } + /* * Send relayd sockets from snapshot output to consumer. Ignore request if the * snapshot output is *not* set with a remote destination. * - * Return 0 on success or else a negative value. + * Return 0 on success or a LTTNG_ERR code. */ static int set_relayd_for_snapshot(struct consumer_output *consumer, struct snapshot_output *snap_output, struct ltt_session *session) { - int ret = 0; + int ret = LTTNG_OK; struct lttng_ht_iter iter; struct consumer_socket *socket; @@ -2374,11 +3561,13 @@ static int set_relayd_for_snapshot(struct consumer_output *consumer, * snapshot output. */ rcu_read_lock(); - cds_lfht_for_each_entry(consumer->socks->ht, &iter.iter, socket, - node.node) { + cds_lfht_for_each_entry(snap_output->consumer->socks->ht, &iter.iter, + socket, node.node) { ret = send_consumer_relayd_sockets(0, session->id, - snap_output->consumer, socket); - if (ret < 0) { + snap_output->consumer, socket, + session->name, session->hostname, + session->live_timer); + if (ret != LTTNG_OK) { rcu_read_unlock(); goto error; } @@ -2392,10 +3581,11 @@ error: /* * Record a kernel snapshot. * - * Return 0 on success or else a negative value. + * Return LTTNG_OK on success or a LTTNG_ERR code. */ static int record_kernel_snapshot(struct ltt_kernel_session *ksess, - struct snapshot_output *output, struct ltt_session *session, int wait) + struct snapshot_output *output, struct ltt_session *session, + int wait, uint64_t nb_packets_per_stream) { int ret; @@ -2403,35 +3593,53 @@ static int record_kernel_snapshot(struct ltt_kernel_session *ksess, assert(output); assert(session); - if (!output->kernel_sockets_copied) { - ret = consumer_copy_sockets(output->consumer, ksess->consumer); - if (ret < 0) { - goto error; - } - output->kernel_sockets_copied = 1; + /* Get the datetime for the snapshot output directory. */ + ret = utils_get_current_time_str("%Y%m%d-%H%M%S", output->datetime, + sizeof(output->datetime)); + if (!ret) { + ret = LTTNG_ERR_INVALID; + goto error; } - ret = set_relayd_for_snapshot(ksess->consumer, output, session); + /* + * Copy kernel session sockets so we can communicate with the right + * consumer for the snapshot record command. + */ + ret = consumer_copy_sockets(output->consumer, ksess->consumer); if (ret < 0) { + ret = LTTNG_ERR_NOMEM; goto error; } - ret = kernel_snapshot_record(ksess, output, wait); - if (ret < 0) { - goto error; + ret = set_relayd_for_snapshot(ksess->consumer, output, session); + if (ret != LTTNG_OK) { + goto error_snapshot; + } + + ret = kernel_snapshot_record(ksess, output, wait, nb_packets_per_stream); + if (ret != LTTNG_OK) { + goto error_snapshot; } + ret = LTTNG_OK; + goto end; + +error_snapshot: + /* Clean up copied sockets so this output can use some other later on. */ + consumer_destroy_output_sockets(output->consumer); error: +end: return ret; } /* * Record a UST snapshot. * - * Return 0 on success or else a negative value. + * Return 0 on success or a LTTNG_ERR error code. */ static int record_ust_snapshot(struct ltt_ust_session *usess, - struct snapshot_output *output, struct ltt_session *session, int wait) + struct snapshot_output *output, struct ltt_session *session, + int wait, uint64_t nb_packets_per_stream) { int ret; @@ -2439,28 +3647,140 @@ static int record_ust_snapshot(struct ltt_ust_session *usess, assert(output); assert(session); - if (!output->ust_sockets_copied) { - ret = consumer_copy_sockets(output->consumer, usess->consumer); - if (ret < 0) { - goto error; - } - output->ust_sockets_copied = 1; + /* Get the datetime for the snapshot output directory. */ + ret = utils_get_current_time_str("%Y%m%d-%H%M%S", output->datetime, + sizeof(output->datetime)); + if (!ret) { + ret = LTTNG_ERR_INVALID; + goto error; } - ret = set_relayd_for_snapshot(usess->consumer, output, session); + /* + * Copy UST session sockets so we can communicate with the right + * consumer for the snapshot record command. + */ + ret = consumer_copy_sockets(output->consumer, usess->consumer); if (ret < 0) { + ret = LTTNG_ERR_NOMEM; goto error; } - ret = ust_app_snapshot_record(usess, output, wait); + ret = set_relayd_for_snapshot(usess->consumer, output, session); + if (ret != LTTNG_OK) { + goto error_snapshot; + } + + ret = ust_app_snapshot_record(usess, output, wait, nb_packets_per_stream); if (ret < 0) { - goto error; + switch (-ret) { + case EINVAL: + ret = LTTNG_ERR_INVALID; + break; + case ENODATA: + ret = LTTNG_ERR_SNAPSHOT_NODATA; + break; + default: + ret = LTTNG_ERR_SNAPSHOT_FAIL; + break; + } + goto error_snapshot; } + ret = LTTNG_OK; + +error_snapshot: + /* Clean up copied sockets so this output can use some other later on. */ + consumer_destroy_output_sockets(output->consumer); error: return ret; } +static +uint64_t get_session_size_one_more_packet_per_stream(struct ltt_session *session, + uint64_t cur_nr_packets) +{ + uint64_t tot_size = 0; + + if (session->kernel_session) { + struct ltt_kernel_channel *chan; + struct ltt_kernel_session *ksess = session->kernel_session; + + cds_list_for_each_entry(chan, &ksess->channel_list.head, list) { + if (cur_nr_packets >= chan->channel->attr.num_subbuf) { + /* + * Don't take channel into account if we + * already grab all its packets. + */ + continue; + } + tot_size += chan->channel->attr.subbuf_size + * chan->stream_count; + } + } + + if (session->ust_session) { + struct ltt_ust_session *usess = session->ust_session; + + tot_size += ust_app_get_size_one_more_packet_per_stream(usess, + cur_nr_packets); + } + + return tot_size; +} + +/* + * Calculate the number of packets we can grab from each stream that + * fits within the overall snapshot max size. + * + * Returns -1 on error, 0 means infinite number of packets, else > 0 is + * the number of packets per stream. + * + * TODO: this approach is not perfect: we consider the worse case + * (packet filling the sub-buffers) as an upper bound, but we could do + * better if we do this calculation while we actually grab the packet + * content: we would know how much padding we don't actually store into + * the file. + * + * This algorithm is currently bounded by the number of packets per + * stream. + * + * Since we call this algorithm before actually grabbing the data, it's + * an approximation: for instance, applications could appear/disappear + * in between this call and actually grabbing data. + */ +static +int64_t get_session_nb_packets_per_stream(struct ltt_session *session, uint64_t max_size) +{ + int64_t size_left; + uint64_t cur_nb_packets = 0; + + if (!max_size) { + return 0; /* Infinite */ + } + + size_left = max_size; + for (;;) { + uint64_t one_more_packet_tot_size; + + one_more_packet_tot_size = get_session_size_one_more_packet_per_stream(session, + cur_nb_packets); + if (!one_more_packet_tot_size) { + /* We are already grabbing all packets. */ + break; + } + size_left -= one_more_packet_tot_size; + if (size_left < 0) { + break; + } + cur_nb_packets++; + } + if (!cur_nb_packets) { + /* Not enough room to grab one packet of each stream, error. */ + return -1; + } + return cur_nb_packets; +} + /* * Command LTTNG_SNAPSHOT_RECORD from lib lttng ctl. * @@ -2473,15 +3793,18 @@ int cmd_snapshot_record(struct ltt_session *session, struct lttng_snapshot_output *output, int wait) { int ret = LTTNG_OK; - struct snapshot_output *tmp_sout = NULL; + unsigned int use_tmp_output = 0; + struct snapshot_output tmp_output; + unsigned int snapshot_success = 0; assert(session); + assert(output); DBG("Cmd snapshot record for session %s", session->name); /* - * Persmission denied to create an output if the session is not set in no - * output mode. + * Permission denied to create an output if the session is not + * set in no output mode. */ if (session->output_traces) { ret = LTTNG_ERR_EPERM; @@ -2489,22 +3812,16 @@ int cmd_snapshot_record(struct ltt_session *session, } /* The session needs to be started at least once. */ - if (!session->started) { + if (!session->has_been_started) { ret = LTTNG_ERR_START_SESSION_ONCE; goto error; } /* Use temporary output for the session. */ - if (output && *output->ctrl_url != '\0') { - tmp_sout = snapshot_output_alloc(); - if (!tmp_sout) { - ret = LTTNG_ERR_NOMEM; - goto error; - } - + if (*output->ctrl_url != '\0') { ret = snapshot_output_init(output->max_size, output->name, output->ctrl_url, output->data_url, session->consumer, - tmp_sout, NULL); + &tmp_output, NULL); if (ret < 0) { if (ret == -ENOMEM) { ret = LTTNG_ERR_NOMEM; @@ -2513,65 +3830,133 @@ int cmd_snapshot_record(struct ltt_session *session, } goto error; } + /* Use the global session count for the temporary snapshot. */ + tmp_output.nb_snapshot = session->snapshot.nb_snapshot; + use_tmp_output = 1; } - if (session->kernel_session) { - struct ltt_kernel_session *ksess = session->kernel_session; + if (use_tmp_output) { + int64_t nb_packets_per_stream; - if (tmp_sout) { - ret = record_kernel_snapshot(ksess, tmp_sout, session, wait); - if (ret < 0) { + nb_packets_per_stream = get_session_nb_packets_per_stream(session, + tmp_output.max_size); + if (nb_packets_per_stream < 0) { + ret = LTTNG_ERR_MAX_SIZE_INVALID; + goto error; + } + + if (session->kernel_session) { + ret = record_kernel_snapshot(session->kernel_session, + &tmp_output, session, + wait, nb_packets_per_stream); + if (ret != LTTNG_OK) { goto error; } - } else { - struct snapshot_output *sout; - struct lttng_ht_iter iter; + } - rcu_read_lock(); - cds_lfht_for_each_entry(session->snapshot.output_ht->ht, - &iter.iter, sout, node.node) { - ret = record_kernel_snapshot(ksess, sout, session, wait); - if (ret < 0) { - rcu_read_unlock(); - goto error; - } + if (session->ust_session) { + ret = record_ust_snapshot(session->ust_session, + &tmp_output, session, + wait, nb_packets_per_stream); + if (ret != LTTNG_OK) { + goto error; } - rcu_read_unlock(); } - } - if (session->ust_session) { - struct ltt_ust_session *usess = session->ust_session; + snapshot_success = 1; + } else { + struct snapshot_output *sout; + struct lttng_ht_iter iter; - if (tmp_sout) { - ret = record_ust_snapshot(usess, tmp_sout, session, wait); - if (ret < 0) { + rcu_read_lock(); + cds_lfht_for_each_entry(session->snapshot.output_ht->ht, + &iter.iter, sout, node.node) { + int64_t nb_packets_per_stream; + + /* + * Make a local copy of the output and assign the possible + * temporary value given by the caller. + */ + memset(&tmp_output, 0, sizeof(tmp_output)); + memcpy(&tmp_output, sout, sizeof(tmp_output)); + + if (output->max_size != (uint64_t) -1ULL) { + tmp_output.max_size = output->max_size; + } + + nb_packets_per_stream = get_session_nb_packets_per_stream(session, + tmp_output.max_size); + if (nb_packets_per_stream < 0) { + ret = LTTNG_ERR_MAX_SIZE_INVALID; + rcu_read_unlock(); goto error; } - } else { - struct snapshot_output *sout; - struct lttng_ht_iter iter; - rcu_read_lock(); - cds_lfht_for_each_entry(session->snapshot.output_ht->ht, - &iter.iter, sout, node.node) { - ret = record_ust_snapshot(usess, tmp_sout, session, wait); - if (ret < 0) { + /* Use temporary name. */ + if (*output->name != '\0') { + strncpy(tmp_output.name, output->name, + sizeof(tmp_output.name)); + } + + tmp_output.nb_snapshot = session->snapshot.nb_snapshot; + + if (session->kernel_session) { + ret = record_kernel_snapshot(session->kernel_session, + &tmp_output, session, + wait, nb_packets_per_stream); + if (ret != LTTNG_OK) { rcu_read_unlock(); goto error; } } - rcu_read_unlock(); + + if (session->ust_session) { + ret = record_ust_snapshot(session->ust_session, + &tmp_output, session, + wait, nb_packets_per_stream); + if (ret != LTTNG_OK) { + rcu_read_unlock(); + goto error; + } + } + snapshot_success = 1; } + rcu_read_unlock(); } -error: - if (tmp_sout) { - snapshot_output_destroy(tmp_sout); + if (snapshot_success) { + session->snapshot.nb_snapshot++; + } else { + ret = LTTNG_ERR_SNAPSHOT_FAIL; } + +error: return ret; } +/* + * Command LTTNG_SET_SESSION_SHM_PATH processed by the client thread. + */ +int cmd_set_session_shm_path(struct ltt_session *session, + const char *shm_path) +{ + /* Safety net */ + assert(session); + + /* + * Can only set shm path before session is started. + */ + if (session->has_been_started) { + return LTTNG_ERR_SESSION_STARTED; + } + + strncpy(session->shm_path, shm_path, + sizeof(session->shm_path)); + session->shm_path[sizeof(session->shm_path) - 1] = '\0'; + + return 0; +} + /* * Init command subsystem. */