+ DBG("Sending kconsumerd header for metadata");
+
+ ret = lttcomm_send_unix_sock(session->consumer_fd, &lkh,
+ sizeof(struct lttcomm_kconsumerd_header));
+ if (ret < 0) {
+ perror("send kconsumerd header");
+ goto error;
+ }
+
+ DBG("Sending metadata stream fd");
+
+ /* Extra protection. It's NOT suppose to be set to 0 at this point */
+ if (session->consumer_fd == 0) {
+ session->consumer_fd = kconsumerd_cmd_sock;
+ }
+
+ if (session->metadata_stream_fd != 0) {
+ /* Send metadata stream fd first */
+ lkm.fd = session->metadata_stream_fd;
+ lkm.state = ACTIVE_FD;
+ lkm.max_sb_size = session->metadata->conf->attr.subbuf_size;
+ lkm.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
+ strncpy(lkm.path_name, session->metadata->pathname, PATH_MAX);
+ lkm.path_name[PATH_MAX - 1] = '\0';
+
+ ret = lttcomm_send_fds_unix_sock(session->consumer_fd, &lkm,
+ &lkm.fd, 1, sizeof(lkm));
+ if (ret < 0) {
+ perror("send kconsumerd fd");
+ goto error;
+ }
+ }
+
+ cds_list_for_each_entry(chan, &session->channel_list.head, list) {
+ ret = send_kconsumerd_channel_fds(session->consumer_fd, chan);
+ if (ret < 0) {
+ goto error;
+ }
+ }
+
+ DBG("Kconsumerd fds (metadata and channel streams) sent");
+
+ return 0;
+
+error:
+ return ret;
+}
+
+/*
+ * Notify UST applications using the shm mmap futex.
+ */
+static int notify_ust_apps(int active)
+{
+ char *wait_shm_mmap;
+
+ DBG("Notifying applications of session daemon state: %d", active);
+
+ /* See shm.c for this call implying mmap, shm and futex calls */
+ wait_shm_mmap = shm_ust_get_mmap(wait_shm_path, is_root);
+ if (wait_shm_mmap == NULL) {
+ goto error;
+ }
+
+ /* Wake waiting process */
+ futex_wait_update((int32_t *) wait_shm_mmap, active);
+
+ /* Apps notified successfully */
+ return 0;
+
+error:
+ return -1;
+}
+
+/*
+ * Setup the outgoing data buffer for the response (llm) by allocating the
+ * right amount of memory and copying the original information from the lsm
+ * structure.
+ *
+ * Return total size of the buffer pointed by buf.
+ */
+static int setup_lttng_msg(struct command_ctx *cmd_ctx, size_t size)
+{
+ int ret, buf_size;
+
+ buf_size = size;
+
+ cmd_ctx->llm = malloc(sizeof(struct lttcomm_lttng_msg) + buf_size);
+ if (cmd_ctx->llm == NULL) {
+ perror("malloc");
+ ret = -ENOMEM;
+ goto error;
+ }
+
+ /* Copy common data */
+ cmd_ctx->llm->cmd_type = cmd_ctx->lsm->cmd_type;
+ cmd_ctx->llm->pid = cmd_ctx->lsm->domain.attr.pid;
+
+ cmd_ctx->llm->data_size = size;
+ cmd_ctx->lttng_msg_size = sizeof(struct lttcomm_lttng_msg) + buf_size;
+
+ return buf_size;
+
+error:
+ return ret;
+}
+
+/*
+ * Update the kernel poll set of all channel fd available over all tracing
+ * session. Add the wakeup pipe at the end of the set.
+ */
+static int update_kernel_poll(struct lttng_poll_event *events)
+{
+ int ret;
+ struct ltt_session *session;
+ struct ltt_kernel_channel *channel;
+
+ DBG("Updating kernel poll set");
+
+ session_lock_list();
+ cds_list_for_each_entry(session, &session_list_ptr->head, list) {
+ session_lock(session);
+ if (session->kernel_session == NULL) {
+ session_unlock(session);
+ continue;
+ }
+
+ cds_list_for_each_entry(channel,
+ &session->kernel_session->channel_list.head, list) {
+ /* Add channel fd to the kernel poll set */
+ ret = lttng_poll_add(events, channel->fd, LPOLLIN | LPOLLRDNORM);
+ if (ret < 0) {
+ session_unlock(session);
+ goto error;
+ }
+ DBG("Channel fd %d added to kernel set", channel->fd);
+ }
+ session_unlock(session);
+ }
+ session_unlock_list();
+
+ return 0;
+
+error:
+ session_unlock_list();
+ return -1;
+}
+
+/*
+ * Find the channel fd from 'fd' over all tracing session. When found, check
+ * for new channel stream and send those stream fds to the kernel consumer.
+ *
+ * Useful for CPU hotplug feature.
+ */
+static int update_kernel_stream(int fd)
+{
+ int ret = 0;
+ struct ltt_session *session;
+ struct ltt_kernel_channel *channel;
+
+ DBG("Updating kernel streams for channel fd %d", fd);
+
+ session_lock_list();
+ cds_list_for_each_entry(session, &session_list_ptr->head, list) {
+ session_lock(session);
+ if (session->kernel_session == NULL) {
+ session_unlock(session);
+ continue;
+ }
+
+ /* This is not suppose to be 0 but this is an extra security check */
+ if (session->kernel_session->consumer_fd == 0) {
+ session->kernel_session->consumer_fd = kconsumerd_cmd_sock;
+ }
+
+ cds_list_for_each_entry(channel,
+ &session->kernel_session->channel_list.head, list) {
+ if (channel->fd == fd) {
+ DBG("Channel found, updating kernel streams");
+ ret = kernel_open_channel_stream(channel);
+ if (ret < 0) {
+ goto error;
+ }
+
+ /*
+ * Have we already sent fds to the consumer? If yes, it means
+ * that tracing is started so it is safe to send our updated
+ * stream fds.
+ */
+ if (session->kernel_session->kconsumer_fds_sent == 1) {
+ ret = send_kconsumerd_channel_fds(
+ session->kernel_session->consumer_fd, channel);
+ if (ret < 0) {
+ goto error;
+ }
+ }
+ goto error;
+ }
+ }
+ session_unlock(session);
+ }
+ session_unlock_list();
+ return ret;
+
+error:
+ session_unlock(session);
+ session_unlock_list();
+ return ret;
+}
+
+/*
+ * This thread manage event coming from the kernel.
+ *
+ * Features supported in this thread:
+ * -) CPU Hotplug
+ */
+static void *thread_manage_kernel(void *data)
+{
+ int ret, i, pollfd, update_poll_flag = 1;
+ uint32_t revents, nb_fd;
+ char tmp;
+ struct lttng_poll_event events;
+
+ DBG("Thread manage kernel started");
+
+ ret = create_thread_poll_set(&events, 2);
+ if (ret < 0) {
+ goto error;
+ }
+
+ ret = lttng_poll_add(&events, kernel_poll_pipe[0], LPOLLIN);
+ if (ret < 0) {
+ goto error;
+ }
+
+ while (1) {
+ if (update_poll_flag == 1) {
+ /*
+ * Reset number of fd in the poll set. Always 2 since there is the thread
+ * quit pipe and the kernel pipe.
+ */
+ events.nb_fd = 2;
+
+ ret = update_kernel_poll(&events);
+ if (ret < 0) {
+ goto error;
+ }
+ update_poll_flag = 0;
+ }
+
+ nb_fd = LTTNG_POLL_GETNB(&events);
+
+ DBG("Thread kernel polling on %d fds", nb_fd);
+
+ /* Zeroed the poll events */
+ lttng_poll_reset(&events);
+
+ /* Poll infinite value of time */
+ ret = lttng_poll_wait(&events, -1);
+ if (ret < 0) {
+ goto error;
+ } else if (ret == 0) {
+ /* Should not happen since timeout is infinite */
+ ERR("Return value of poll is 0 with an infinite timeout.\n"
+ "This should not have happened! Continuing...");
+ continue;
+ }
+
+ for (i = 0; i < nb_fd; i++) {
+ /* Fetch once the poll data */
+ revents = LTTNG_POLL_GETEV(&events, i);
+ pollfd = LTTNG_POLL_GETFD(&events, i);
+
+ /* Thread quit pipe has been closed. Killing thread. */
+ ret = check_thread_quit_pipe(pollfd, revents);
+ if (ret) {
+ goto error;
+ }
+
+ /* Check for data on kernel pipe */
+ if (pollfd == kernel_poll_pipe[0] && (revents & LPOLLIN)) {
+ ret = read(kernel_poll_pipe[0], &tmp, 1);
+ update_poll_flag = 1;
+ continue;
+ } else {
+ /*
+ * New CPU detected by the kernel. Adding kernel stream to
+ * kernel session and updating the kernel consumer
+ */
+ if (revents & LPOLLIN) {
+ ret = update_kernel_stream(pollfd);
+ if (ret < 0) {
+ continue;
+ }
+ break;
+ /*
+ * TODO: We might want to handle the LPOLLERR | LPOLLHUP
+ * and unregister kernel stream at this point.
+ */
+ }
+ }
+ }
+ }
+
+error:
+ DBG("Kernel thread dying");
+ close(kernel_poll_pipe[0]);
+ close(kernel_poll_pipe[1]);
+
+ lttng_poll_clean(&events);
+
+ return NULL;
+}
+
+/*
+ * This thread manage the kconsumerd error sent back to the session daemon.
+ */
+static void *thread_manage_kconsumerd(void *data)
+{
+ int sock = 0, i, ret, pollfd;
+ uint32_t revents, nb_fd;
+ enum lttcomm_return_code code;
+ struct lttng_poll_event events;
+
+ DBG("[thread] Manage kconsumerd started");
+
+ ret = lttcomm_listen_unix_sock(kconsumerd_err_sock);
+ if (ret < 0) {
+ goto error;
+ }
+
+ /*
+ * Pass 2 as size here for the thread quit pipe and kconsumerd_err_sock.
+ * Nothing more will be added to this poll set.
+ */
+ ret = create_thread_poll_set(&events, 2);
+ if (ret < 0) {
+ goto error;
+ }
+
+ ret = lttng_poll_add(&events, kconsumerd_err_sock, LPOLLIN | LPOLLRDHUP);
+ if (ret < 0) {
+ goto error;
+ }
+
+ nb_fd = LTTNG_POLL_GETNB(&events);
+
+ /* Inifinite blocking call, waiting for transmission */
+ ret = lttng_poll_wait(&events, -1);
+ if (ret < 0) {
+ goto error;
+ }
+
+ for (i = 0; i < nb_fd; i++) {
+ /* Fetch once the poll data */
+ revents = LTTNG_POLL_GETEV(&events, i);
+ pollfd = LTTNG_POLL_GETFD(&events, i);
+
+ /* Thread quit pipe has been closed. Killing thread. */
+ ret = check_thread_quit_pipe(pollfd, revents);
+ if (ret) {
+ goto error;
+ }
+
+ /* Event on the registration socket */
+ if (pollfd == kconsumerd_err_sock) {
+ if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
+ ERR("Kconsumerd err socket poll error");
+ goto error;
+ }
+ }
+ }
+
+ sock = lttcomm_accept_unix_sock(kconsumerd_err_sock);
+ if (sock < 0) {
+ goto error;
+ }
+
+ DBG2("Receiving code from kconsumerd_err_sock");
+
+ /* Getting status code from kconsumerd */
+ ret = lttcomm_recv_unix_sock(sock, &code,
+ sizeof(enum lttcomm_return_code));
+ if (ret <= 0) {
+ goto error;
+ }
+
+ if (code == KCONSUMERD_COMMAND_SOCK_READY) {
+ kconsumerd_cmd_sock =
+ lttcomm_connect_unix_sock(kconsumerd_cmd_unix_sock_path);
+ if (kconsumerd_cmd_sock < 0) {
+ sem_post(&kconsumerd_sem);
+ perror("kconsumerd connect");
+ goto error;
+ }
+ /* Signal condition to tell that the kconsumerd is ready */
+ sem_post(&kconsumerd_sem);
+ DBG("Kconsumerd command socket ready");
+ } else {
+ ERR("Kconsumerd error when waiting for SOCK_READY : %s",
+ lttcomm_get_readable_code(-code));
+ goto error;
+ }
+
+ /* Remove the kconsumerd error sock since we've established a connexion */
+ ret = lttng_poll_del(&events, kconsumerd_err_sock);
+ if (ret < 0) {
+ goto error;
+ }
+
+ ret = lttng_poll_add(&events, sock, LPOLLIN | LPOLLRDHUP);
+ if (ret < 0) {
+ goto error;
+ }
+
+ /* Update number of fd */
+ nb_fd = LTTNG_POLL_GETNB(&events);
+
+ /* Inifinite blocking call, waiting for transmission */
+ ret = lttng_poll_wait(&events, -1);
+ if (ret < 0) {
+ goto error;
+ }
+
+ for (i = 0; i < nb_fd; i++) {
+ /* Fetch once the poll data */
+ revents = LTTNG_POLL_GETEV(&events, i);
+ pollfd = LTTNG_POLL_GETFD(&events, i);
+
+ /* Thread quit pipe has been closed. Killing thread. */
+ ret = check_thread_quit_pipe(pollfd, revents);
+ if (ret) {
+ goto error;
+ }
+
+ /* Event on the kconsumerd socket */
+ if (pollfd == sock) {
+ if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
+ ERR("Kconsumerd err socket second poll error");
+ goto error;
+ }
+ }
+ }
+
+ /* Wait for any kconsumerd error */
+ ret = lttcomm_recv_unix_sock(sock, &code,
+ sizeof(enum lttcomm_return_code));
+ if (ret <= 0) {
+ ERR("Kconsumerd closed the command socket");
+ goto error;
+ }
+
+ ERR("Kconsumerd return code : %s", lttcomm_get_readable_code(-code));
+
+error:
+ DBG("Kconsumerd thread dying");
+ close(kconsumerd_err_sock);
+ close(kconsumerd_cmd_sock);
+ close(sock);
+
+ unlink(kconsumerd_err_unix_sock_path);
+ unlink(kconsumerd_cmd_unix_sock_path);
+ kconsumerd_pid = 0;
+
+ lttng_poll_clean(&events);
+
+ return NULL;
+}
+
+/*
+ * This thread manage application communication.
+ */
+static void *thread_manage_apps(void *data)
+{
+ int i, ret, pollfd;
+ uint32_t revents, nb_fd;
+ struct ust_command ust_cmd;
+ struct lttng_poll_event events;
+
+ DBG("[thread] Manage application started");
+
+ ret = create_thread_poll_set(&events, 2);
+ if (ret < 0) {
+ goto error;
+ }
+
+ ret = lttng_poll_add(&events, apps_cmd_pipe[0], LPOLLIN | LPOLLRDHUP);
+ if (ret < 0) {
+ goto error;
+ }
+
+ while (1) {
+ /* Zeroed the events structure */
+ lttng_poll_reset(&events);
+
+ nb_fd = LTTNG_POLL_GETNB(&events);
+
+ DBG("Apps thread polling on %d fds", nb_fd);
+
+ /* Inifinite blocking call, waiting for transmission */
+ ret = lttng_poll_wait(&events, -1);
+ if (ret < 0) {
+ goto error;
+ }
+
+ for (i = 0; i < nb_fd; i++) {
+ /* Fetch once the poll data */
+ revents = LTTNG_POLL_GETEV(&events, i);
+ pollfd = LTTNG_POLL_GETFD(&events, i);
+
+ /* Thread quit pipe has been closed. Killing thread. */
+ ret = check_thread_quit_pipe(pollfd, revents);
+ if (ret) {
+ goto error;
+ }
+
+ /* Inspect the apps cmd pipe */
+ if (pollfd == apps_cmd_pipe[0]) {
+ if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
+ ERR("Apps command pipe error");
+ goto error;
+ } else if (revents & LPOLLIN) {
+ /* Empty pipe */
+ ret = read(apps_cmd_pipe[0], &ust_cmd, sizeof(ust_cmd));
+ if (ret < 0 || ret < sizeof(ust_cmd)) {
+ perror("read apps cmd pipe");
+ goto error;
+ }
+
+ /* Register applicaton to the session daemon */
+ ret = ust_app_register(&ust_cmd.reg_msg,
+ ust_cmd.sock);
+ if (ret < 0) {
+ /* Only critical ENOMEM error can be returned here */
+ goto error;
+ }
+
+ ret = ustctl_register_done(ust_cmd.sock);
+ if (ret < 0) {
+ /*
+ * If the registration is not possible, we simply
+ * unregister the apps and continue
+ */
+ ust_app_unregister(ust_cmd.sock);
+ } else {
+ /*
+ * We just need here to monitor the close of the UST
+ * socket and poll set monitor those by default.
+ */
+ ret = lttng_poll_add(&events, ust_cmd.sock, 0);
+ if (ret < 0) {
+ goto error;
+ }
+
+ DBG("Apps with sock %d added to poll set",
+ ust_cmd.sock);
+ }
+ break;
+ }
+ } else {
+ /*
+ * At this point, we know that a registered application made
+ * the event at poll_wait.
+ */
+ if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
+ /* Removing from the poll set */
+ ret = lttng_poll_del(&events, pollfd);
+ if (ret < 0) {
+ goto error;
+ }
+
+ /* Socket closed */
+ ust_app_unregister(pollfd);
+ break;
+ }
+ }
+ }
+ }
+
+error:
+ DBG("Application communication apps dying");
+ close(apps_cmd_pipe[0]);
+ close(apps_cmd_pipe[1]);
+
+ lttng_poll_clean(&events);
+
+ return NULL;
+}
+
+/*
+ * Dispatch request from the registration threads to the application
+ * communication thread.
+ */
+static void *thread_dispatch_ust_registration(void *data)
+{
+ int ret;
+ struct cds_wfq_node *node;
+ struct ust_command *ust_cmd = NULL;
+
+ DBG("[thread] Dispatch UST command started");
+
+ while (!dispatch_thread_exit) {
+ /* Atomically prepare the queue futex */
+ futex_nto1_prepare(&ust_cmd_queue.futex);
+
+ do {
+ /* Dequeue command for registration */
+ node = cds_wfq_dequeue_blocking(&ust_cmd_queue.queue);
+ if (node == NULL) {
+ DBG("Waked up but nothing in the UST command queue");
+ /* Continue thread execution */
+ break;
+ }
+
+ ust_cmd = caa_container_of(node, struct ust_command, node);
+
+ DBG("Dispatching UST registration pid:%d ppid:%d uid:%d"
+ " gid:%d sock:%d name:%s (version %d.%d)",
+ ust_cmd->reg_msg.pid, ust_cmd->reg_msg.ppid,
+ ust_cmd->reg_msg.uid, ust_cmd->reg_msg.gid,
+ ust_cmd->sock, ust_cmd->reg_msg.name,
+ ust_cmd->reg_msg.major, ust_cmd->reg_msg.minor);
+ /*
+ * Inform apps thread of the new application registration. This
+ * call is blocking so we can be assured that the data will be read
+ * at some point in time or wait to the end of the world :)
+ */
+ ret = write(apps_cmd_pipe[1], ust_cmd,
+ sizeof(struct ust_command));
+ if (ret < 0) {
+ perror("write apps cmd pipe");
+ if (errno == EBADF) {
+ /*
+ * We can't inform the application thread to process
+ * registration. We will exit or else application
+ * registration will not occur and tracing will never
+ * start.
+ */
+ goto error;
+ }
+ }
+ free(ust_cmd);
+ } while (node != NULL);
+
+ /* Futex wait on queue. Blocking call on futex() */
+ futex_nto1_wait(&ust_cmd_queue.futex);
+ }
+
+error:
+ DBG("Dispatch thread dying");
+ return NULL;
+}
+
+/*
+ * This thread manage application registration.
+ */
+static void *thread_registration_apps(void *data)
+{
+ int sock = 0, i, ret, pollfd;
+ uint32_t revents, nb_fd;
+ struct lttng_poll_event events;
+ /*
+ * Get allocated in this thread, enqueued to a global queue, dequeued and
+ * freed in the manage apps thread.
+ */
+ struct ust_command *ust_cmd = NULL;
+
+ DBG("[thread] Manage application registration started");
+
+ ret = lttcomm_listen_unix_sock(apps_sock);
+ if (ret < 0) {
+ goto error;
+ }
+
+ /*
+ * Pass 2 as size here for the thread quit pipe and apps socket. Nothing
+ * more will be added to this poll set.
+ */
+ ret = create_thread_poll_set(&events, 2);
+ if (ret < 0) {
+ goto error;
+ }
+
+ /* Add the application registration socket */
+ ret = lttng_poll_add(&events, apps_sock, LPOLLIN | LPOLLRDHUP);
+ if (ret < 0) {
+ goto error;
+ }
+
+ /* Notify all applications to register */
+ ret = notify_ust_apps(1);
+ if (ret < 0) {
+ ERR("Failed to notify applications or create the wait shared memory.\n"
+ "Execution continues but there might be problem for already\n"
+ "running applications that wishes to register.");
+ }
+
+ while (1) {
+ DBG("Accepting application registration");
+
+ nb_fd = LTTNG_POLL_GETNB(&events);
+
+ /* Inifinite blocking call, waiting for transmission */
+ ret = lttng_poll_wait(&events, -1);
+ if (ret < 0) {
+ goto error;
+ }
+
+ for (i = 0; i < nb_fd; i++) {
+ /* Fetch once the poll data */
+ revents = LTTNG_POLL_GETEV(&events, i);
+ pollfd = LTTNG_POLL_GETFD(&events, i);
+
+ /* Thread quit pipe has been closed. Killing thread. */
+ ret = check_thread_quit_pipe(pollfd, revents);
+ if (ret) {
+ goto error;
+ }
+
+ /* Event on the registration socket */
+ if (pollfd == apps_sock) {
+ if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
+ ERR("Register apps socket poll error");
+ goto error;
+ } else if (revents & LPOLLIN) {
+ sock = lttcomm_accept_unix_sock(apps_sock);
+ if (sock < 0) {
+ goto error;
+ }
+
+ /* Create UST registration command for enqueuing */
+ ust_cmd = malloc(sizeof(struct ust_command));
+ if (ust_cmd == NULL) {
+ perror("ust command malloc");
+ goto error;
+ }
+
+ /*
+ * Using message-based transmissions to ensure we don't
+ * have to deal with partially received messages.
+ */
+ ret = lttcomm_recv_unix_sock(sock, &ust_cmd->reg_msg,
+ sizeof(struct ust_register_msg));
+ if (ret < 0 || ret < sizeof(struct ust_register_msg)) {
+ if (ret < 0) {
+ perror("lttcomm_recv_unix_sock register apps");
+ } else {
+ ERR("Wrong size received on apps register");
+ }
+ free(ust_cmd);
+ close(sock);
+ continue;
+ }
+
+ ust_cmd->sock = sock;
+
+ DBG("UST registration received with pid:%d ppid:%d uid:%d"
+ " gid:%d sock:%d name:%s (version %d.%d)",
+ ust_cmd->reg_msg.pid, ust_cmd->reg_msg.ppid,
+ ust_cmd->reg_msg.uid, ust_cmd->reg_msg.gid,
+ ust_cmd->sock, ust_cmd->reg_msg.name,
+ ust_cmd->reg_msg.major, ust_cmd->reg_msg.minor);
+
+ /*
+ * Lock free enqueue the registration request. The red pill
+ * has been taken! This apps will be part of the *system*.
+ */
+ cds_wfq_enqueue(&ust_cmd_queue.queue, &ust_cmd->node);
+
+ /*
+ * Wake the registration queue futex. Implicit memory
+ * barrier with the exchange in cds_wfq_enqueue.
+ */
+ futex_nto1_wake(&ust_cmd_queue.futex);
+ }
+ }
+ }
+ }
+
+error:
+ DBG("UST Registration thread dying");
+
+ /* Notify that the registration thread is gone */
+ notify_ust_apps(0);
+
+ close(apps_sock);
+ close(sock);
+ unlink(apps_unix_sock_path);
+
+ lttng_poll_clean(&events);
+
+ return NULL;
+}
+
+/*
+ * Start the thread_manage_kconsumerd. This must be done after a kconsumerd
+ * exec or it will fails.
+ */
+static int spawn_kconsumerd_thread(void)
+{
+ int ret;
+ struct timespec timeout;
+
+ timeout.tv_sec = DEFAULT_SEM_WAIT_TIMEOUT;
+ timeout.tv_nsec = 0;
+
+ /* Setup semaphore */
+ ret = sem_init(&kconsumerd_sem, 0, 0);
+ if (ret < 0) {
+ PERROR("sem_init kconsumerd_sem");
+ goto error;
+ }
+
+ ret = pthread_create(&kconsumerd_thread, NULL,
+ thread_manage_kconsumerd, (void *) NULL);
+ if (ret != 0) {
+ PERROR("pthread_create kconsumerd");
+ ret = -1;
+ goto error;
+ }
+
+ /* Get time for sem_timedwait absolute timeout */
+ ret = clock_gettime(CLOCK_REALTIME, &timeout);
+ if (ret < 0) {
+ PERROR("clock_gettime spawn kconsumerd");
+ /* Infinite wait for the kconsumerd thread to be ready */
+ ret = sem_wait(&kconsumerd_sem);
+ } else {
+ /* Normal timeout if the gettime was successful */
+ timeout.tv_sec += DEFAULT_SEM_WAIT_TIMEOUT;
+ ret = sem_timedwait(&kconsumerd_sem, &timeout);
+ }
+
+ if (ret < 0) {
+ if (errno == ETIMEDOUT) {
+ /*
+ * Call has timed out so we kill the kconsumerd_thread and return
+ * an error.
+ */
+ ERR("The kconsumerd thread was never ready. Killing it");
+ ret = pthread_cancel(kconsumerd_thread);
+ if (ret < 0) {
+ PERROR("pthread_cancel kconsumerd_thread");
+ }
+ } else {
+ PERROR("semaphore wait failed kconsumerd thread");
+ }
+ goto error;
+ }
+
+ pthread_mutex_lock(&kconsumerd_pid_mutex);
+ if (kconsumerd_pid == 0) {
+ ERR("Kconsumerd did not start");
+ pthread_mutex_unlock(&kconsumerd_pid_mutex);
+ goto error;
+ }
+ pthread_mutex_unlock(&kconsumerd_pid_mutex);
+
+ return 0;
+
+error:
+ return ret;
+}
+
+/*
+ * Join kernel consumer thread
+ */
+static int join_kconsumerd_thread(void)
+{
+ void *status;
+ int ret;
+
+ if (kconsumerd_pid != 0) {
+ ret = kill(kconsumerd_pid, SIGTERM);
+ if (ret) {
+ ERR("Error killing kconsumerd");
+ return ret;
+ }
+ return pthread_join(kconsumerd_thread, &status);
+ } else {
+ return 0;
+ }
+}
+
+/*
+ * Fork and exec a kernel consumer daemon (kconsumerd).
+ *
+ * Return pid if successful else -1.
+ */
+static pid_t spawn_kconsumerd(void)
+{
+ int ret;
+ pid_t pid;
+ const char *verbosity;
+
+ DBG("Spawning kconsumerd");
+
+ pid = fork();
+ if (pid == 0) {
+ /*
+ * Exec kconsumerd.
+ */
+ if (opt_verbose > 1 || opt_verbose_kconsumerd) {
+ verbosity = "--verbose";
+ } else {
+ verbosity = "--quiet";
+ }
+ execl(INSTALL_BIN_PATH "/ltt-kconsumerd",
+ "ltt-kconsumerd", verbosity, NULL);