+ DBG("[thread] Manage kconsumerd started");
+
+ ret = lttcomm_listen_unix_sock(kconsumerd_err_sock);
+ if (ret < 0) {
+ goto error;
+ }
+
+ /* First fd is always the quit pipe */
+ pollfd[0].fd = thread_quit_pipe[0];
+
+ /* Apps socket */
+ pollfd[1].fd = kconsumerd_err_sock;
+ pollfd[1].events = POLLIN;
+
+ /* Inifinite blocking call, waiting for transmission */
+ ret = poll(pollfd, 2, -1);
+ if (ret < 0) {
+ perror("poll kconsumerd thread");
+ goto error;
+ }
+
+ /* Thread quit pipe has been closed. Killing thread. */
+ if (pollfd[0].revents == POLLNVAL) {
+ goto error;
+ } else if (pollfd[1].revents == POLLERR) {
+ ERR("Kconsumerd err socket poll error");
+ goto error;
+ }
+
+ sock = lttcomm_accept_unix_sock(kconsumerd_err_sock);
+ if (sock < 0) {
+ goto error;
+ }
+
+ /* 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 {
+ DBG("Kconsumerd error when waiting for SOCK_READY : %s",
+ lttcomm_get_readable_code(-code));
+ goto error;
+ }
+
+ /* Kconsumerd err socket */
+ pollfd[1].fd = sock;
+ pollfd[1].events = POLLIN;
+
+ /* Inifinite blocking call, waiting for transmission */
+ ret = poll(pollfd, 2, -1);
+ if (ret < 0) {
+ perror("poll kconsumerd thread");
+ goto error;
+ }
+
+ /* Thread quit pipe has been closed. Killing thread. */
+ if (pollfd[0].revents == POLLNVAL) {
+ goto error;
+ } else if (pollfd[1].revents == POLLERR) {
+ 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");
+ if (kconsumerd_err_sock) {
+ close(kconsumerd_err_sock);
+ }
+ if (kconsumerd_cmd_sock) {
+ close(kconsumerd_cmd_sock);
+ }
+ if (sock) {
+ close(sock);
+ }
+
+ unlink(kconsumerd_err_unix_sock_path);
+ unlink(kconsumerd_cmd_unix_sock_path);
+
+ kconsumerd_pid = 0;
+ return NULL;
+}
+
+/*
+ * Reallocate the apps command pollfd structure of nb_fd size.
+ *
+ * The first two fds must be there at all time.
+ */
+static int update_apps_cmd_pollfd(unsigned int nb_fd, struct pollfd **pollfd)
+{
+ /* Can't accept pollfd less than 2 */
+ if (nb_fd < 2) {
+ goto end;
+ }
+
+ *pollfd = realloc(*pollfd, nb_fd * sizeof(struct pollfd));
+ if (*pollfd == NULL) {
+ perror("realloc manage apps pollfd");
+ goto error;
+ }
+
+ /* First fd is always the quit pipe */
+ (*pollfd)[0].fd = thread_quit_pipe[0];
+ /* Apps command pipe */
+ (*pollfd)[1].fd = apps_cmd_pipe[0];
+ (*pollfd)[1].events = POLLIN;
+
+ DBG("Apps cmd pollfd realloc of size %d", nb_fd);
+
+end:
+ return 0;
+
+error:
+ return -1;
+}
+
+/*
+ * Send registration done packet to the application.
+ */
+static int send_ust_register_done(int sock)
+{
+ struct lttcomm_ust_msg lum;
+
+ DBG("Sending register done command to %d", sock);
+
+ lum.cmd = LTTNG_UST_REGISTER_DONE;
+ lum.handle = LTTNG_UST_ROOT_HANDLE;
+
+ return ustcomm_send_command(sock, &lum);
+}
+
+/*
+ * This thread manage application communication.
+ */
+static void *thread_manage_apps(void *data)
+{
+ int i, ret, count;
+ unsigned int nb_fd = 2;
+ int update_poll_flag = 1;
+ struct pollfd *pollfd = NULL;
+ struct ust_command ust_cmd;
+
+ DBG("[thread] Manage application started");
+
+ ust_cmd.sock = -1;
+
+ while (1) {
+ /* See if we have a valid socket to add to pollfd */
+ if (ust_cmd.sock != -1) {
+ nb_fd++;
+ update_poll_flag = 1;
+ }
+
+ /* The pollfd struct must be updated */
+ if (update_poll_flag) {
+ ret = update_apps_cmd_pollfd(nb_fd, &pollfd);
+ if (ret < 0) {
+ /* malloc failed so we quit */
+ goto error;
+ }
+ if (ust_cmd.sock != -1) {
+ /* Update pollfd with the new UST socket */
+ DBG("Adding sock %d to apps cmd pollfd", ust_cmd.sock);
+ pollfd[nb_fd - 1].fd = ust_cmd.sock;
+ pollfd[nb_fd - 1].events = POLLHUP | POLLNVAL;
+ ust_cmd.sock = -1;
+ }
+ }
+
+ DBG("Apps thread polling on %d fds", nb_fd);
+
+ /* Inifinite blocking call, waiting for transmission */
+ ret = poll(pollfd, nb_fd, -1);
+ if (ret < 0) {
+ perror("poll apps thread");
+ goto error;
+ }
+
+ /* Thread quit pipe has been closed. Killing thread. */
+ if (pollfd[0].revents == POLLNVAL) {
+ goto error;
+ } else if (pollfd[1].revents == POLLERR) {
+ ERR("Apps command pipe poll error");
+ goto error;
+ } else if (pollfd[1].revents == POLLIN) {
+ /* 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 = register_traceable_app(&ust_cmd.reg_msg, ust_cmd.sock);
+ if (ret < 0) {
+ /* Only critical ENOMEM error can be returned here */
+ goto error;
+ }
+
+ ret = send_ust_register_done(ust_cmd.sock);
+ if (ret < 0) {
+ /*
+ * If the registration is not possible, we simply unregister
+ * the apps and continue
+ */
+ unregister_traceable_app(ust_cmd.sock);
+ }
+ }
+
+ count = nb_fd;
+ for (i = 2; i < count; i++) {
+ /* Apps socket is closed/hungup */
+ switch (pollfd[i].revents) {
+ case POLLNVAL:
+ case POLLHUP:
+ /* Pipe closed */
+ unregister_traceable_app(pollfd[i].fd);
+ nb_fd--;
+ }
+ }
+
+ if (nb_fd != count) {
+ update_poll_flag = 1;
+ }
+ }
+
+error:
+ DBG("Application communication apps dying");
+ close(apps_cmd_pipe[0]);
+ close(apps_cmd_pipe[1]);
+
+ free(pollfd);
+
+ 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 sock:%d",
+ ust_cmd->reg_msg.pid, ust_cmd->sock);
+ /*
+ * 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, ret;
+ struct pollfd pollfd[2];
+ /*
+ * 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;
+ }
+
+ /* First fd is always the quit pipe */
+ pollfd[0].fd = thread_quit_pipe[0];
+
+ /* Apps socket */
+ pollfd[1].fd = apps_sock;
+ pollfd[1].events = POLLIN;
+
+ /* Notify all applications to register */
+ //notify_apps(default_global_apps_pipe);
+
+ while (1) {
+ DBG("Accepting application registration");
+
+ /* Inifinite blocking call, waiting for transmission */
+ ret = poll(pollfd, 2, -1);
+ if (ret < 0) {
+ perror("poll register apps thread");
+ goto error;
+ }
+
+ /* Thread quit pipe has been closed. Killing thread. */
+ if (pollfd[0].revents == POLLNVAL) {
+ goto error;
+ } else if (pollfd[1].revents == POLLERR) {
+ ERR("Register apps socket poll error");
+ goto error;
+ }
+
+ 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)) {
+ perror("lttcomm_recv_unix_sock register apps");
+ free(ust_cmd);
+ close(sock);
+ continue;
+ }
+
+ ust_cmd->sock = sock;
+
+ /*
+ * 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);
+
+ DBG("Thread manage apps informed of queued node with sock:%d pid:%d",
+ sock, ust_cmd->reg_msg.pid);
+ }
+
+error:
+ DBG("Register apps thread dying");
+ if (apps_sock) {
+ close(apps_sock);
+ }
+ if (sock) {
+ close(sock);
+ }
+
+ unlink(apps_unix_sock_path);
+ 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;
+
+ /* Setup semaphore */
+ sem_init(&kconsumerd_sem, 0, 0);
+
+ ret = pthread_create(&kconsumerd_thread, NULL, thread_manage_kconsumerd, (void *) NULL);
+ if (ret != 0) {
+ perror("pthread_create kconsumerd");
+ goto error;
+ }
+
+ /* Wait for the kconsumerd thread to be ready */
+ sem_wait(&kconsumerd_sem);
+
+ if (kconsumerd_pid == 0) {
+ ERR("Kconsumerd did not start");
+ goto error;
+ }
+
+ return 0;
+
+error:
+ ret = LTTCOMM_KERN_CONSUMER_FAIL;
+ 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);
+ if (errno != 0) {
+ perror("kernel start consumer exec");
+ }
+ exit(EXIT_FAILURE);
+ } else if (pid > 0) {
+ ret = pid;
+ goto error;
+ } else {
+ perror("kernel start consumer fork");
+ ret = -errno;
+ goto error;
+ }
+
+error:
+ return ret;
+}
+
+/*
+ * Spawn the kconsumerd daemon and session daemon thread.
+ */
+static int start_kconsumerd(void)
+{
+ int ret;
+
+ pthread_mutex_lock(&kconsumerd_pid_mutex);
+ if (kconsumerd_pid != 0) {
+ pthread_mutex_unlock(&kconsumerd_pid_mutex);
+ goto end;
+ }
+
+ ret = spawn_kconsumerd();
+ if (ret < 0) {
+ ERR("Spawning kconsumerd failed");
+ ret = LTTCOMM_KERN_CONSUMER_FAIL;
+ pthread_mutex_unlock(&kconsumerd_pid_mutex);
+ goto error;
+ }
+
+ /* Setting up the global kconsumerd_pid */
+ kconsumerd_pid = ret;
+ pthread_mutex_unlock(&kconsumerd_pid_mutex);
+
+ DBG("Kconsumerd pid %d", ret);
+
+ DBG("Spawning kconsumerd thread");
+ ret = spawn_kconsumerd_thread();
+ if (ret < 0) {
+ ERR("Fatal error spawning kconsumerd thread");
+ goto error;
+ }
+
+end:
+ return 0;
+
+error:
+ return ret;
+}
+
+/*
+ * modprobe_kernel_modules
+ */
+static int modprobe_kernel_modules(void)
+{
+ int ret = 0, i;
+ char modprobe[256];
+
+ for (i = 0; i < ARRAY_SIZE(kernel_modules_list); i++) {
+ ret = snprintf(modprobe, sizeof(modprobe),
+ "/sbin/modprobe %s%s",
+ kernel_modules_list[i].required ? "" : "--quiet ",
+ kernel_modules_list[i].name);
+ if (ret < 0) {
+ perror("snprintf modprobe");
+ goto error;
+ }
+ modprobe[sizeof(modprobe) - 1] = '\0';
+ ret = system(modprobe);
+ if (ret == -1) {
+ ERR("Unable to launch modprobe for module %s",
+ kernel_modules_list[i].name);
+ } else if (kernel_modules_list[i].required
+ && WEXITSTATUS(ret) != 0) {
+ ERR("Unable to load module %s",
+ kernel_modules_list[i].name);
+ } else {
+ DBG("Modprobe successfully %s",
+ kernel_modules_list[i].name);
+ }
+ }
+
+error:
+ return ret;
+}
+
+/*
+ * modprobe_remove_kernel_modules
+ * Remove modules in reverse load order.
+ */
+static int modprobe_remove_kernel_modules(void)
+{
+ int ret = 0, i;
+ char modprobe[256];
+
+ for (i = ARRAY_SIZE(kernel_modules_list) - 1; i >= 0; i--) {
+ ret = snprintf(modprobe, sizeof(modprobe),
+ "/sbin/modprobe --remove --quiet %s",
+ kernel_modules_list[i].name);
+ if (ret < 0) {
+ perror("snprintf modprobe --remove");
+ goto error;
+ }
+ modprobe[sizeof(modprobe) - 1] = '\0';
+ ret = system(modprobe);
+ if (ret == -1) {
+ ERR("Unable to launch modprobe --remove for module %s",
+ kernel_modules_list[i].name);
+ } else if (kernel_modules_list[i].required
+ && WEXITSTATUS(ret) != 0) {
+ ERR("Unable to remove module %s",
+ kernel_modules_list[i].name);
+ } else {
+ DBG("Modprobe removal successful %s",
+ kernel_modules_list[i].name);
+ }
+ }
+
+error:
+ return ret;
+}
+
+/*
+ * mount_debugfs
+ */
+static int mount_debugfs(char *path)
+{
+ int ret;
+ char *type = "debugfs";
+
+ ret = mkdir_recursive(path, S_IRWXU | S_IRWXG, geteuid(), getegid());
+ if (ret < 0) {
+ goto error;
+ }
+
+ ret = mount(type, path, type, 0, NULL);
+ if (ret < 0) {
+ perror("mount debugfs");
+ goto error;
+ }
+
+ DBG("Mounted debugfs successfully at %s", path);
+
+error:
+ return ret;
+}
+
+/*
+ * Setup necessary data for kernel tracer action.
+ */
+static void init_kernel_tracer(void)
+{
+ int ret;
+ char *proc_mounts = "/proc/mounts";
+ char line[256];
+ char *debugfs_path = NULL, *lttng_path;
+ FILE *fp;
+
+ /* Detect debugfs */
+ fp = fopen(proc_mounts, "r");
+ if (fp == NULL) {
+ ERR("Unable to probe %s", proc_mounts);
+ goto error;
+ }
+
+ while (fgets(line, sizeof(line), fp) != NULL) {
+ if (strstr(line, "debugfs") != NULL) {
+ /* Remove first string */
+ strtok(line, " ");
+ /* Dup string here so we can reuse line later on */
+ debugfs_path = strdup(strtok(NULL, " "));
+ DBG("Got debugfs path : %s", debugfs_path);
+ break;
+ }
+ }
+
+ fclose(fp);
+
+ /* Mount debugfs if needded */
+ if (debugfs_path == NULL) {
+ ret = asprintf(&debugfs_path, "/mnt/debugfs");
+ if (ret < 0) {
+ perror("asprintf debugfs path");
+ goto error;
+ }
+ ret = mount_debugfs(debugfs_path);
+ if (ret < 0) {
+ goto error;
+ }
+ }
+
+ /* Modprobe lttng kernel modules */
+ ret = modprobe_kernel_modules();
+ if (ret < 0) {
+ goto error;
+ }