Launch the client management thread using lttng_thread
[lttng-tools.git] / src / bin / lttng-sessiond / main.c
index c82e0095bc1e476b015a164a61975a661d39ff95..1641ebeb876dfe2bc820ce6b0ea5d608148656c1 100644 (file)
@@ -50,7 +50,6 @@
 #include <common/daemonize.h>
 #include <common/config/session-config.h>
 #include <common/dynamic-buffer.h>
-#include <lttng/userspace-probe-internal.h>
 #include <lttng/event-internal.h>
 
 #include "lttng-sessiond.h"
@@ -83,6 +82,7 @@
 #include "sessiond-config.h"
 #include "timer.h"
 #include "thread.h"
+#include "client.h"
 
 static const char *help_msg =
 #ifdef LTTNG_EMBED_HELP
@@ -98,44 +98,6 @@ static int lockfile_fd = -1;
 /* Set to 1 when a SIGUSR1 signal is received. */
 static int recv_child_signal;
 
-static struct lttng_kernel_tracer_version kernel_tracer_version;
-static struct lttng_kernel_tracer_abi_version kernel_tracer_abi_version;
-
-/*
- * Consumer daemon specific control data. Every value not initialized here is
- * set to 0 by the static definition.
- */
-static struct consumer_data kconsumer_data = {
-       .type = LTTNG_CONSUMER_KERNEL,
-       .err_sock = -1,
-       .cmd_sock = -1,
-       .channel_monitor_pipe = -1,
-       .pid_mutex = PTHREAD_MUTEX_INITIALIZER,
-       .lock = PTHREAD_MUTEX_INITIALIZER,
-       .cond = PTHREAD_COND_INITIALIZER,
-       .cond_mutex = PTHREAD_MUTEX_INITIALIZER,
-};
-static struct consumer_data ustconsumer64_data = {
-       .type = LTTNG_CONSUMER64_UST,
-       .err_sock = -1,
-       .cmd_sock = -1,
-       .channel_monitor_pipe = -1,
-       .pid_mutex = PTHREAD_MUTEX_INITIALIZER,
-       .lock = PTHREAD_MUTEX_INITIALIZER,
-       .cond = PTHREAD_COND_INITIALIZER,
-       .cond_mutex = PTHREAD_MUTEX_INITIALIZER,
-};
-static struct consumer_data ustconsumer32_data = {
-       .type = LTTNG_CONSUMER32_UST,
-       .err_sock = -1,
-       .cmd_sock = -1,
-       .channel_monitor_pipe = -1,
-       .pid_mutex = PTHREAD_MUTEX_INITIALIZER,
-       .lock = PTHREAD_MUTEX_INITIALIZER,
-       .cond = PTHREAD_COND_INITIALIZER,
-       .cond_mutex = PTHREAD_MUTEX_INITIALIZER,
-};
-
 /* Command line options */
 static const struct option long_options[] = {
        { "client-sock", required_argument, 0, 'c' },
@@ -175,8 +137,6 @@ static const char *config_ignore_options[] = { "help", "version", "config" };
 /* Shared between threads */
 static int dispatch_thread_exit;
 
-/* Sockets and FDs */
-static int client_sock = -1;
 static int apps_sock = -1;
 
 /*
@@ -189,7 +149,6 @@ static int apps_cmd_pipe[2] = { -1, -1 };
 static pthread_t apps_thread;
 static pthread_t apps_notify_thread;
 static pthread_t reg_apps_thread;
-static pthread_t client_thread;
 static pthread_t kernel_thread;
 static pthread_t dispatch_thread;
 static pthread_t agent_reg_thread;
@@ -208,40 +167,6 @@ static struct ust_cmd_queue ust_cmd_queue;
 
 static const char *module_proc_lttng = "/proc/lttng";
 
-/*
- * Consumer daemon state which is changed when spawning it, killing it or in
- * case of a fatal error.
- */
-enum consumerd_state {
-       CONSUMER_STARTED = 1,
-       CONSUMER_STOPPED = 2,
-       CONSUMER_ERROR   = 3,
-};
-
-/*
- * This consumer daemon state is used to validate if a client command will be
- * able to reach the consumer. If not, the client is informed. For instance,
- * doing a "lttng start" when the consumer state is set to ERROR will return an
- * error to the client.
- *
- * The following example shows a possible race condition of this scheme:
- *
- * consumer thread error happens
- *                                    client cmd arrives
- *                                    client cmd checks state -> still OK
- * consumer thread exit, sets error
- *                                    client cmd try to talk to consumer
- *                                    ...
- *
- * However, since the consumer is a different daemon, we have no way of making
- * sure the command will reach it safely even with this state flag. This is why
- * we consider that up to the state validation during command processing, the
- * command is safe. After that, we can not guarantee the correctness of the
- * client request vis-a-vis the consumer.
- */
-static enum consumerd_state ust_consumerd_state;
-static enum consumerd_state kernel_consumerd_state;
-
 /* Load session thread information to operate. */
 static struct load_session_thread_data *load_info;
 
@@ -466,39 +391,6 @@ static void sessiond_cleanup_options(void)
        run_as_destroy_worker();
 }
 
-/*
- * Send data on a unix socket using the liblttsessiondcomm API.
- *
- * Return lttcomm error code.
- */
-static int send_unix_sock(int sock, void *buf, size_t len)
-{
-       /* Check valid length */
-       if (len == 0) {
-               return -1;
-       }
-
-       return lttcomm_send_unix_sock(sock, buf, len);
-}
-
-/*
- * Free memory of a command context structure.
- */
-static void clean_command_ctx(struct command_ctx **cmd_ctx)
-{
-       DBG("Clean command context structure");
-       if (*cmd_ctx) {
-               if ((*cmd_ctx)->llm) {
-                       free((*cmd_ctx)->llm);
-               }
-               if ((*cmd_ctx)->lsm) {
-                       free((*cmd_ctx)->lsm);
-               }
-               free(*cmd_ctx);
-               *cmd_ctx = NULL;
-       }
-}
-
 /*
  * Notify UST applications using the shm mmap futex.
  */
@@ -524,62 +416,6 @@ 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 0 on success, negative value on error.
- */
-static int setup_lttng_msg(struct command_ctx *cmd_ctx,
-       const void *payload_buf, size_t payload_len,
-       const void *cmd_header_buf, size_t cmd_header_len)
-{
-       int ret = 0;
-       const size_t header_len = sizeof(struct lttcomm_lttng_msg);
-       const size_t cmd_header_offset = header_len;
-       const size_t payload_offset = cmd_header_offset + cmd_header_len;
-       const size_t total_msg_size = header_len + cmd_header_len + payload_len;
-
-       cmd_ctx->llm = zmalloc(total_msg_size);
-
-       if (cmd_ctx->llm == NULL) {
-               PERROR("zmalloc");
-               ret = -ENOMEM;
-               goto end;
-       }
-
-       /* 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->cmd_header_size = cmd_header_len;
-       cmd_ctx->llm->data_size = payload_len;
-       cmd_ctx->lttng_msg_size = total_msg_size;
-
-       /* Copy command header */
-       if (cmd_header_len) {
-               memcpy(((uint8_t *) cmd_ctx->llm) + cmd_header_offset, cmd_header_buf,
-                       cmd_header_len);
-       }
-
-       /* Copy payload */
-       if (payload_len) {
-               memcpy(((uint8_t *) cmd_ctx->llm) + payload_offset, payload_buf,
-                       payload_len);
-       }
-
-end:
-       return ret;
-}
-
-/*
- * Version of setup_lttng_msg() without command header.
- */
-static int setup_lttng_msg_no_cmd_header(struct command_ctx *cmd_ctx,
-       void *payload_buf, size_t payload_len)
-{
-       return setup_lttng_msg(cmd_ctx, payload_buf, payload_len, NULL, 0);
-}
 /*
  * Update the kernel poll set of all channel fd available over all tracing
  * session. Add the wakeup pipe at the end of the set.
@@ -939,7 +775,7 @@ static void signal_consumer_condition(struct consumer_data *data, int state)
 /*
  * This thread manage the consumer error sent back to the session daemon.
  */
-static void *thread_manage_consumer(void *data)
+void *thread_manage_consumer(void *data)
 {
        int sock = -1, i, ret, pollfd, err = -1, should_quit = 0;
        uint32_t revents, nb_fd;
@@ -2088,371 +1924,6 @@ error_testpoint:
        return NULL;
 }
 
-/*
- * Start the thread_manage_consumer. This must be done after a lttng-consumerd
- * exec or it will fails.
- */
-static int spawn_consumer_thread(struct consumer_data *consumer_data)
-{
-       int ret, clock_ret;
-       struct timespec timeout;
-
-       /*
-        * Make sure we set the readiness flag to 0 because we are NOT ready.
-        * This access to consumer_thread_is_ready does not need to be
-        * protected by consumer_data.cond_mutex (yet) since the consumer
-        * management thread has not been started at this point.
-        */
-       consumer_data->consumer_thread_is_ready = 0;
-
-       /* Setup pthread condition */
-       ret = pthread_condattr_init(&consumer_data->condattr);
-       if (ret) {
-               errno = ret;
-               PERROR("pthread_condattr_init consumer data");
-               goto error;
-       }
-
-       /*
-        * Set the monotonic clock in order to make sure we DO NOT jump in time
-        * between the clock_gettime() call and the timedwait call. See bug #324
-        * for a more details and how we noticed it.
-        */
-       ret = pthread_condattr_setclock(&consumer_data->condattr, CLOCK_MONOTONIC);
-       if (ret) {
-               errno = ret;
-               PERROR("pthread_condattr_setclock consumer data");
-               goto error;
-       }
-
-       ret = pthread_cond_init(&consumer_data->cond, &consumer_data->condattr);
-       if (ret) {
-               errno = ret;
-               PERROR("pthread_cond_init consumer data");
-               goto error;
-       }
-
-       ret = pthread_create(&consumer_data->thread, default_pthread_attr(),
-                       thread_manage_consumer, consumer_data);
-       if (ret) {
-               errno = ret;
-               PERROR("pthread_create consumer");
-               ret = -1;
-               goto error;
-       }
-
-       /* We are about to wait on a pthread condition */
-       pthread_mutex_lock(&consumer_data->cond_mutex);
-
-       /* Get time for sem_timedwait absolute timeout */
-       clock_ret = lttng_clock_gettime(CLOCK_MONOTONIC, &timeout);
-       /*
-        * Set the timeout for the condition timed wait even if the clock gettime
-        * call fails since we might loop on that call and we want to avoid to
-        * increment the timeout too many times.
-        */
-       timeout.tv_sec += DEFAULT_SEM_WAIT_TIMEOUT;
-
-       /*
-        * The following loop COULD be skipped in some conditions so this is why we
-        * set ret to 0 in order to make sure at least one round of the loop is
-        * done.
-        */
-       ret = 0;
-
-       /*
-        * Loop until the condition is reached or when a timeout is reached. Note
-        * that the pthread_cond_timedwait(P) man page specifies that EINTR can NOT
-        * be returned but the pthread_cond(3), from the glibc-doc, says that it is
-        * possible. This loop does not take any chances and works with both of
-        * them.
-        */
-       while (!consumer_data->consumer_thread_is_ready && ret != ETIMEDOUT) {
-               if (clock_ret < 0) {
-                       PERROR("clock_gettime spawn consumer");
-                       /* Infinite wait for the consumerd thread to be ready */
-                       ret = pthread_cond_wait(&consumer_data->cond,
-                                       &consumer_data->cond_mutex);
-               } else {
-                       ret = pthread_cond_timedwait(&consumer_data->cond,
-                                       &consumer_data->cond_mutex, &timeout);
-               }
-       }
-
-       /* Release the pthread condition */
-       pthread_mutex_unlock(&consumer_data->cond_mutex);
-
-       if (ret != 0) {
-               errno = ret;
-               if (ret == ETIMEDOUT) {
-                       int pth_ret;
-
-                       /*
-                        * Call has timed out so we kill the kconsumerd_thread and return
-                        * an error.
-                        */
-                       ERR("Condition timed out. The consumer thread was never ready."
-                                       " Killing it");
-                       pth_ret = pthread_cancel(consumer_data->thread);
-                       if (pth_ret < 0) {
-                               PERROR("pthread_cancel consumer thread");
-                       }
-               } else {
-                       PERROR("pthread_cond_wait failed consumer thread");
-               }
-               /* Caller is expecting a negative value on failure. */
-               ret = -1;
-               goto error;
-       }
-
-       pthread_mutex_lock(&consumer_data->pid_mutex);
-       if (consumer_data->pid == 0) {
-               ERR("Consumerd did not start");
-               pthread_mutex_unlock(&consumer_data->pid_mutex);
-               goto error;
-       }
-       pthread_mutex_unlock(&consumer_data->pid_mutex);
-
-       return 0;
-
-error:
-       return ret;
-}
-
-/*
- * Join consumer thread
- */
-static int join_consumer_thread(struct consumer_data *consumer_data)
-{
-       void *status;
-
-       /* Consumer pid must be a real one. */
-       if (consumer_data->pid > 0) {
-               int ret;
-               ret = kill(consumer_data->pid, SIGTERM);
-               if (ret) {
-                       PERROR("Error killing consumer daemon");
-                       return ret;
-               }
-               return pthread_join(consumer_data->thread, &status);
-       } else {
-               return 0;
-       }
-}
-
-/*
- * Fork and exec a consumer daemon (consumerd).
- *
- * Return pid if successful else -1.
- */
-static pid_t spawn_consumerd(struct consumer_data *consumer_data)
-{
-       int ret;
-       pid_t pid;
-       const char *consumer_to_use;
-       const char *verbosity;
-       struct stat st;
-
-       DBG("Spawning consumerd");
-
-       pid = fork();
-       if (pid == 0) {
-               /*
-                * Exec consumerd.
-                */
-               if (config.verbose_consumer) {
-                       verbosity = "--verbose";
-               } else if (lttng_opt_quiet) {
-                       verbosity = "--quiet";
-               } else {
-                       verbosity = "";
-               }
-
-               switch (consumer_data->type) {
-               case LTTNG_CONSUMER_KERNEL:
-                       /*
-                        * Find out which consumerd to execute. We will first try the
-                        * 64-bit path, then the sessiond's installation directory, and
-                        * fallback on the 32-bit one,
-                        */
-                       DBG3("Looking for a kernel consumer at these locations:");
-                       DBG3("  1) %s", config.consumerd64_bin_path.value ? : "NULL");
-                       DBG3("  2) %s/%s", INSTALL_BIN_PATH, DEFAULT_CONSUMERD_FILE);
-                       DBG3("  3) %s", config.consumerd32_bin_path.value ? : "NULL");
-                       if (stat(config.consumerd64_bin_path.value, &st) == 0) {
-                               DBG3("Found location #1");
-                               consumer_to_use = config.consumerd64_bin_path.value;
-                       } else if (stat(INSTALL_BIN_PATH "/" DEFAULT_CONSUMERD_FILE, &st) == 0) {
-                               DBG3("Found location #2");
-                               consumer_to_use = INSTALL_BIN_PATH "/" DEFAULT_CONSUMERD_FILE;
-                       } else if (config.consumerd32_bin_path.value &&
-                                       stat(config.consumerd32_bin_path.value, &st) == 0) {
-                               DBG3("Found location #3");
-                               consumer_to_use = config.consumerd32_bin_path.value;
-                       } else {
-                               DBG("Could not find any valid consumerd executable");
-                               ret = -EINVAL;
-                               goto error;
-                       }
-                       DBG("Using kernel consumer at: %s",  consumer_to_use);
-                       (void) execl(consumer_to_use,
-                               "lttng-consumerd", verbosity, "-k",
-                               "--consumerd-cmd-sock", consumer_data->cmd_unix_sock_path,
-                               "--consumerd-err-sock", consumer_data->err_unix_sock_path,
-                               "--group", config.tracing_group_name.value,
-                               NULL);
-                       break;
-               case LTTNG_CONSUMER64_UST:
-               {
-                       if (config.consumerd64_lib_dir.value) {
-                               char *tmp;
-                               size_t tmplen;
-                               char *tmpnew;
-
-                               tmp = lttng_secure_getenv("LD_LIBRARY_PATH");
-                               if (!tmp) {
-                                       tmp = "";
-                               }
-                               tmplen = strlen(config.consumerd64_lib_dir.value) + 1 /* : */ + strlen(tmp);
-                               tmpnew = zmalloc(tmplen + 1 /* \0 */);
-                               if (!tmpnew) {
-                                       ret = -ENOMEM;
-                                       goto error;
-                               }
-                               strcat(tmpnew, config.consumerd64_lib_dir.value);
-                               if (tmp[0] != '\0') {
-                                       strcat(tmpnew, ":");
-                                       strcat(tmpnew, tmp);
-                               }
-                               ret = setenv("LD_LIBRARY_PATH", tmpnew, 1);
-                               free(tmpnew);
-                               if (ret) {
-                                       ret = -errno;
-                                       goto error;
-                               }
-                       }
-                       DBG("Using 64-bit UST consumer at: %s",  config.consumerd64_bin_path.value);
-                       (void) execl(config.consumerd64_bin_path.value, "lttng-consumerd", verbosity, "-u",
-                                       "--consumerd-cmd-sock", consumer_data->cmd_unix_sock_path,
-                                       "--consumerd-err-sock", consumer_data->err_unix_sock_path,
-                                       "--group", config.tracing_group_name.value,
-                                       NULL);
-                       break;
-               }
-               case LTTNG_CONSUMER32_UST:
-               {
-                       if (config.consumerd32_lib_dir.value) {
-                               char *tmp;
-                               size_t tmplen;
-                               char *tmpnew;
-
-                               tmp = lttng_secure_getenv("LD_LIBRARY_PATH");
-                               if (!tmp) {
-                                       tmp = "";
-                               }
-                               tmplen = strlen(config.consumerd32_lib_dir.value) + 1 /* : */ + strlen(tmp);
-                               tmpnew = zmalloc(tmplen + 1 /* \0 */);
-                               if (!tmpnew) {
-                                       ret = -ENOMEM;
-                                       goto error;
-                               }
-                               strcat(tmpnew, config.consumerd32_lib_dir.value);
-                               if (tmp[0] != '\0') {
-                                       strcat(tmpnew, ":");
-                                       strcat(tmpnew, tmp);
-                               }
-                               ret = setenv("LD_LIBRARY_PATH", tmpnew, 1);
-                               free(tmpnew);
-                               if (ret) {
-                                       ret = -errno;
-                                       goto error;
-                               }
-                       }
-                       DBG("Using 32-bit UST consumer at: %s",  config.consumerd32_bin_path.value);
-                       (void) execl(config.consumerd32_bin_path.value, "lttng-consumerd", verbosity, "-u",
-                                       "--consumerd-cmd-sock", consumer_data->cmd_unix_sock_path,
-                                       "--consumerd-err-sock", consumer_data->err_unix_sock_path,
-                                       "--group", config.tracing_group_name.value,
-                                       NULL);
-                       break;
-               }
-               default:
-                       ERR("unknown consumer type");
-                       errno = 0;
-               }
-               if (errno != 0) {
-                       PERROR("Consumer execl()");
-               }
-               /* Reaching this point, we got a failure on our execl(). */
-               exit(EXIT_FAILURE);
-       } else if (pid > 0) {
-               ret = pid;
-       } else {
-               PERROR("start consumer fork");
-               ret = -errno;
-       }
-error:
-       return ret;
-}
-
-/*
- * Spawn the consumerd daemon and session daemon thread.
- */
-static int start_consumerd(struct consumer_data *consumer_data)
-{
-       int ret;
-
-       /*
-        * Set the listen() state on the socket since there is a possible race
-        * between the exec() of the consumer daemon and this call if place in the
-        * consumer thread. See bug #366 for more details.
-        */
-       ret = lttcomm_listen_unix_sock(consumer_data->err_sock);
-       if (ret < 0) {
-               goto error;
-       }
-
-       pthread_mutex_lock(&consumer_data->pid_mutex);
-       if (consumer_data->pid != 0) {
-               pthread_mutex_unlock(&consumer_data->pid_mutex);
-               goto end;
-       }
-
-       ret = spawn_consumerd(consumer_data);
-       if (ret < 0) {
-               ERR("Spawning consumerd failed");
-               pthread_mutex_unlock(&consumer_data->pid_mutex);
-               goto error;
-       }
-
-       /* Setting up the consumer_data pid */
-       consumer_data->pid = ret;
-       DBG2("Consumer pid %d", consumer_data->pid);
-       pthread_mutex_unlock(&consumer_data->pid_mutex);
-
-       DBG2("Spawning consumer control thread");
-       ret = spawn_consumer_thread(consumer_data);
-       if (ret < 0) {
-               ERR("Fatal error spawning consumer control thread");
-               goto error;
-       }
-
-end:
-       return 0;
-
-error:
-       /* Cleanup already created sockets on error. */
-       if (consumer_data->err_sock >= 0) {
-               int err;
-
-               err = close(consumer_data->err_sock);
-               if (err < 0) {
-                       PERROR("close consumer data error socket");
-               }
-       }
-       return ret;
-}
-
 /*
  * Setup necessary data for kernel tracer action.
  */
@@ -2528,2009 +1999,20 @@ error:
        }
 }
 
-
-/*
- * Copy consumer output from the tracing session to the domain session. The
- * function also applies the right modification on a per domain basis for the
- * trace files destination directory.
- *
- * Should *NOT* be called with RCU read-side lock held.
- */
-static int copy_session_consumer(int domain, struct ltt_session *session)
+static int string_match(const char *str1, const char *str2)
 {
-       int ret;
-       const char *dir_name;
-       struct consumer_output *consumer;
-
-       assert(session);
-       assert(session->consumer);
-
-       switch (domain) {
-       case LTTNG_DOMAIN_KERNEL:
-               DBG3("Copying tracing session consumer output in kernel session");
-               /*
-                * XXX: We should audit the session creation and what this function
-                * does "extra" in order to avoid a destroy since this function is used
-                * in the domain session creation (kernel and ust) only. Same for UST
-                * domain.
-                */
-               if (session->kernel_session->consumer) {
-                       consumer_output_put(session->kernel_session->consumer);
-               }
-               session->kernel_session->consumer =
-                       consumer_copy_output(session->consumer);
-               /* Ease our life a bit for the next part */
-               consumer = session->kernel_session->consumer;
-               dir_name = DEFAULT_KERNEL_TRACE_DIR;
-               break;
-       case LTTNG_DOMAIN_JUL:
-       case LTTNG_DOMAIN_LOG4J:
-       case LTTNG_DOMAIN_PYTHON:
-       case LTTNG_DOMAIN_UST:
-               DBG3("Copying tracing session consumer output in UST session");
-               if (session->ust_session->consumer) {
-                       consumer_output_put(session->ust_session->consumer);
-               }
-               session->ust_session->consumer =
-                       consumer_copy_output(session->consumer);
-               /* Ease our life a bit for the next part */
-               consumer = session->ust_session->consumer;
-               dir_name = DEFAULT_UST_TRACE_DIR;
-               break;
-       default:
-               ret = LTTNG_ERR_UNKNOWN_DOMAIN;
-               goto error;
-       }
-
-       /* Append correct directory to subdir */
-       strncat(consumer->subdir, dir_name,
-                       sizeof(consumer->subdir) - strlen(consumer->subdir) - 1);
-       DBG3("Copy session consumer subdir %s", consumer->subdir);
-
-       ret = LTTNG_OK;
-
-error:
-       return ret;
+       return (str1 && str2) && !strcmp(str1, str2);
 }
 
 /*
- * Create an UST session and add it to the session ust list.
+ * Take an option from the getopt output and set it in the right variable to be
+ * used later.
  *
- * Should *NOT* be called with RCU read-side lock held.
+ * Return 0 on success else a negative value.
  */
-static int create_ust_session(struct ltt_session *session,
-               struct lttng_domain *domain)
+static int set_option(int opt, const char *arg, const char *optname)
 {
-       int ret;
-       struct ltt_ust_session *lus = NULL;
-
-       assert(session);
-       assert(domain);
-       assert(session->consumer);
-
-       switch (domain->type) {
-       case LTTNG_DOMAIN_JUL:
-       case LTTNG_DOMAIN_LOG4J:
-       case LTTNG_DOMAIN_PYTHON:
-       case LTTNG_DOMAIN_UST:
-               break;
-       default:
-               ERR("Unknown UST domain on create session %d", domain->type);
-               ret = LTTNG_ERR_UNKNOWN_DOMAIN;
-               goto error;
-       }
-
-       DBG("Creating UST session");
-
-       lus = trace_ust_create_session(session->id);
-       if (lus == NULL) {
-               ret = LTTNG_ERR_UST_SESS_FAIL;
-               goto error;
-       }
-
-       lus->uid = session->uid;
-       lus->gid = session->gid;
-       lus->output_traces = session->output_traces;
-       lus->snapshot_mode = session->snapshot_mode;
-       lus->live_timer_interval = session->live_timer;
-       session->ust_session = lus;
-       if (session->shm_path[0]) {
-               strncpy(lus->root_shm_path, session->shm_path,
-                       sizeof(lus->root_shm_path));
-               lus->root_shm_path[sizeof(lus->root_shm_path) - 1] = '\0';
-               strncpy(lus->shm_path, session->shm_path,
-                       sizeof(lus->shm_path));
-               lus->shm_path[sizeof(lus->shm_path) - 1] = '\0';
-               strncat(lus->shm_path, "/ust",
-                       sizeof(lus->shm_path) - strlen(lus->shm_path) - 1);
-       }
-       /* Copy session output to the newly created UST session */
-       ret = copy_session_consumer(domain->type, session);
-       if (ret != LTTNG_OK) {
-               goto error;
-       }
-
-       return LTTNG_OK;
-
-error:
-       free(lus);
-       session->ust_session = NULL;
-       return ret;
-}
-
-/*
- * Create a kernel tracer session then create the default channel.
- */
-static int create_kernel_session(struct ltt_session *session)
-{
-       int ret;
-
-       DBG("Creating kernel session");
-
-       ret = kernel_create_session(session, kernel_tracer_fd);
-       if (ret < 0) {
-               ret = LTTNG_ERR_KERN_SESS_FAIL;
-               goto error;
-       }
-
-       /* Code flow safety */
-       assert(session->kernel_session);
-
-       /* Copy session output to the newly created Kernel session */
-       ret = copy_session_consumer(LTTNG_DOMAIN_KERNEL, session);
-       if (ret != LTTNG_OK) {
-               goto error;
-       }
-
-       session->kernel_session->uid = session->uid;
-       session->kernel_session->gid = session->gid;
-       session->kernel_session->output_traces = session->output_traces;
-       session->kernel_session->snapshot_mode = session->snapshot_mode;
-
-       return LTTNG_OK;
-
-error:
-       trace_kernel_destroy_session(session->kernel_session);
-       session->kernel_session = NULL;
-       return ret;
-}
-
-/*
- * Count number of session permitted by uid/gid.
- */
-static unsigned int lttng_sessions_count(uid_t uid, gid_t gid)
-{
-       unsigned int i = 0;
-       struct ltt_session *session;
-       const struct ltt_session_list *session_list = session_get_list();
-
-       DBG("Counting number of available session for UID %d GID %d",
-                       uid, gid);
-       cds_list_for_each_entry(session, &session_list->head, list) {
-               if (!session_get(session)) {
-                       continue;
-               }
-               session_lock(session);
-               /* Only count the sessions the user can control. */
-               if (session_access_ok(session, uid, gid) &&
-                               !session->destroyed) {
-                       i++;
-               }
-               session_unlock(session);
-               session_put(session);
-       }
-       return i;
-}
-
-static int receive_userspace_probe(struct command_ctx *cmd_ctx, int sock,
-               int *sock_error, struct lttng_event *event)
-{
-       int fd, ret;
-       struct lttng_userspace_probe_location *probe_location;
-       const struct lttng_userspace_probe_location_lookup_method *lookup = NULL;
-       struct lttng_dynamic_buffer probe_location_buffer;
-       struct lttng_buffer_view buffer_view;
-
-       /*
-        * Create a buffer to store the serialized version of the probe
-        * location.
-        */
-       lttng_dynamic_buffer_init(&probe_location_buffer);
-       ret = lttng_dynamic_buffer_set_size(&probe_location_buffer,
-                       cmd_ctx->lsm->u.enable.userspace_probe_location_len);
-       if (ret) {
-               ret = LTTNG_ERR_NOMEM;
-               goto error;
-       }
-
-       /*
-        * Receive the probe location.
-        */
-       ret = lttcomm_recv_unix_sock(sock, probe_location_buffer.data,
-                       probe_location_buffer.size);
-       if (ret <= 0) {
-               DBG("Nothing recv() from client var len data... continuing");
-               *sock_error = 1;
-               lttng_dynamic_buffer_reset(&probe_location_buffer);
-               ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
-               goto error;
-       }
-
-       buffer_view = lttng_buffer_view_from_dynamic_buffer(
-                       &probe_location_buffer, 0, probe_location_buffer.size);
-
-       /*
-        * Extract the probe location from the serialized version.
-        */
-       ret = lttng_userspace_probe_location_create_from_buffer(
-                               &buffer_view, &probe_location);
-       if (ret < 0) {
-               WARN("Failed to create a userspace probe location from the received buffer");
-               lttng_dynamic_buffer_reset( &probe_location_buffer);
-               ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
-               goto error;
-       }
-
-       /*
-        * Receive the file descriptor to the target binary from the client.
-        */
-       DBG("Receiving userspace probe target FD from client ...");
-       ret = lttcomm_recv_fds_unix_sock(sock, &fd, 1);
-       if (ret <= 0) {
-               DBG("Nothing recv() from client userspace probe fd... continuing");
-               *sock_error = 1;
-               ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
-               goto error;
-       }
-
-       /*
-        * Set the file descriptor received from the client through the unix
-        * socket in the probe location.
-        */
-       lookup = lttng_userspace_probe_location_get_lookup_method(probe_location);
-       if (!lookup) {
-               ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
-               goto error;
-       }
-
-       /*
-        * From the kernel tracer's perspective, all userspace probe event types
-        * are all the same: a file and an offset.
-        */
-       switch (lttng_userspace_probe_location_lookup_method_get_type(lookup)) {
-       case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_FUNCTION_ELF:
-               ret = lttng_userspace_probe_location_function_set_binary_fd(
-                               probe_location, fd);
-               break;
-       case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_TRACEPOINT_SDT:
-               ret = lttng_userspace_probe_location_tracepoint_set_binary_fd(
-                               probe_location, fd);
-               break;
-       default:
-               ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
-               goto error;
-       }
-
-       if (ret) {
-               ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
-               goto error;
-       }
-
-       /* Attach the probe location to the event. */
-       ret = lttng_event_set_userspace_probe_location(event, probe_location);
-       if (ret) {
-               ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
-               goto error;
-       }
-
-       lttng_dynamic_buffer_reset(&probe_location_buffer);
-error:
-       return ret;
-}
-
-/*
- * Check if the current kernel tracer supports the session rotation feature.
- * Return 1 if it does, 0 otherwise.
- */
-static int check_rotate_compatible(void)
-{
-       int ret = 1;
-
-       if (kernel_tracer_version.major != 2 || kernel_tracer_version.minor < 11) {
-               DBG("Kernel tracer version is not compatible with the rotation feature");
-               ret = 0;
-       }
-
-       return ret;
-}
-
-/*
- * Process the command requested by the lttng client within the command
- * context structure. This function make sure that the return structure (llm)
- * is set and ready for transmission before returning.
- *
- * Return any error encountered or 0 for success.
- *
- * "sock" is only used for special-case var. len data.
- *
- * Should *NOT* be called with RCU read-side lock held.
- */
-static int process_client_msg(struct command_ctx *cmd_ctx, int sock,
-               int *sock_error)
-{
-       int ret = LTTNG_OK;
-       int need_tracing_session = 1;
-       int need_domain;
-
-       DBG("Processing client command %d", cmd_ctx->lsm->cmd_type);
-
-       assert(!rcu_read_ongoing());
-
-       *sock_error = 0;
-
-       switch (cmd_ctx->lsm->cmd_type) {
-       case LTTNG_CREATE_SESSION:
-       case LTTNG_CREATE_SESSION_SNAPSHOT:
-       case LTTNG_CREATE_SESSION_LIVE:
-       case LTTNG_DESTROY_SESSION:
-       case LTTNG_LIST_SESSIONS:
-       case LTTNG_LIST_DOMAINS:
-       case LTTNG_START_TRACE:
-       case LTTNG_STOP_TRACE:
-       case LTTNG_DATA_PENDING:
-       case LTTNG_SNAPSHOT_ADD_OUTPUT:
-       case LTTNG_SNAPSHOT_DEL_OUTPUT:
-       case LTTNG_SNAPSHOT_LIST_OUTPUT:
-       case LTTNG_SNAPSHOT_RECORD:
-       case LTTNG_SAVE_SESSION:
-       case LTTNG_SET_SESSION_SHM_PATH:
-       case LTTNG_REGENERATE_METADATA:
-       case LTTNG_REGENERATE_STATEDUMP:
-       case LTTNG_REGISTER_TRIGGER:
-       case LTTNG_UNREGISTER_TRIGGER:
-       case LTTNG_ROTATE_SESSION:
-       case LTTNG_ROTATION_GET_INFO:
-       case LTTNG_ROTATION_SET_SCHEDULE:
-       case LTTNG_SESSION_LIST_ROTATION_SCHEDULES:
-               need_domain = 0;
-               break;
-       default:
-               need_domain = 1;
-       }
-
-       if (config.no_kernel && need_domain
-                       && cmd_ctx->lsm->domain.type == LTTNG_DOMAIN_KERNEL) {
-               if (!is_root) {
-                       ret = LTTNG_ERR_NEED_ROOT_SESSIOND;
-               } else {
-                       ret = LTTNG_ERR_KERN_NA;
-               }
-               goto error;
-       }
-
-       /* Deny register consumer if we already have a spawned consumer. */
-       if (cmd_ctx->lsm->cmd_type == LTTNG_REGISTER_CONSUMER) {
-               pthread_mutex_lock(&kconsumer_data.pid_mutex);
-               if (kconsumer_data.pid > 0) {
-                       ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
-                       pthread_mutex_unlock(&kconsumer_data.pid_mutex);
-                       goto error;
-               }
-               pthread_mutex_unlock(&kconsumer_data.pid_mutex);
-       }
-
-       /*
-        * Check for command that don't needs to allocate a returned payload. We do
-        * this here so we don't have to make the call for no payload at each
-        * command.
-        */
-       switch(cmd_ctx->lsm->cmd_type) {
-       case LTTNG_LIST_SESSIONS:
-       case LTTNG_LIST_TRACEPOINTS:
-       case LTTNG_LIST_TRACEPOINT_FIELDS:
-       case LTTNG_LIST_DOMAINS:
-       case LTTNG_LIST_CHANNELS:
-       case LTTNG_LIST_EVENTS:
-       case LTTNG_LIST_SYSCALLS:
-       case LTTNG_LIST_TRACKER_PIDS:
-       case LTTNG_DATA_PENDING:
-       case LTTNG_ROTATE_SESSION:
-       case LTTNG_ROTATION_GET_INFO:
-       case LTTNG_SESSION_LIST_ROTATION_SCHEDULES:
-               break;
-       default:
-               /* Setup lttng message with no payload */
-               ret = setup_lttng_msg_no_cmd_header(cmd_ctx, NULL, 0);
-               if (ret < 0) {
-                       /* This label does not try to unlock the session */
-                       goto init_setup_error;
-               }
-       }
-
-       /* Commands that DO NOT need a session. */
-       switch (cmd_ctx->lsm->cmd_type) {
-       case LTTNG_CREATE_SESSION:
-       case LTTNG_CREATE_SESSION_SNAPSHOT:
-       case LTTNG_CREATE_SESSION_LIVE:
-       case LTTNG_LIST_SESSIONS:
-       case LTTNG_LIST_TRACEPOINTS:
-       case LTTNG_LIST_SYSCALLS:
-       case LTTNG_LIST_TRACEPOINT_FIELDS:
-       case LTTNG_SAVE_SESSION:
-       case LTTNG_REGISTER_TRIGGER:
-       case LTTNG_UNREGISTER_TRIGGER:
-               need_tracing_session = 0;
-               break;
-       default:
-               DBG("Getting session %s by name", cmd_ctx->lsm->session.name);
-               /*
-                * We keep the session list lock across _all_ commands
-                * for now, because the per-session lock does not
-                * handle teardown properly.
-                */
-               session_lock_list();
-               cmd_ctx->session = session_find_by_name(cmd_ctx->lsm->session.name);
-               if (cmd_ctx->session == NULL) {
-                       ret = LTTNG_ERR_SESS_NOT_FOUND;
-                       goto error;
-               } else {
-                       /* Acquire lock for the session */
-                       session_lock(cmd_ctx->session);
-               }
-               break;
-       }
-
-       /*
-        * Commands that need a valid session but should NOT create one if none
-        * exists. Instead of creating one and destroying it when the command is
-        * handled, process that right before so we save some round trip in useless
-        * code path.
-        */
-       switch (cmd_ctx->lsm->cmd_type) {
-       case LTTNG_DISABLE_CHANNEL:
-       case LTTNG_DISABLE_EVENT:
-               switch (cmd_ctx->lsm->domain.type) {
-               case LTTNG_DOMAIN_KERNEL:
-                       if (!cmd_ctx->session->kernel_session) {
-                               ret = LTTNG_ERR_NO_CHANNEL;
-                               goto error;
-                       }
-                       break;
-               case LTTNG_DOMAIN_JUL:
-               case LTTNG_DOMAIN_LOG4J:
-               case LTTNG_DOMAIN_PYTHON:
-               case LTTNG_DOMAIN_UST:
-                       if (!cmd_ctx->session->ust_session) {
-                               ret = LTTNG_ERR_NO_CHANNEL;
-                               goto error;
-                       }
-                       break;
-               default:
-                       ret = LTTNG_ERR_UNKNOWN_DOMAIN;
-                       goto error;
-               }
-       default:
-               break;
-       }
-
-       if (!need_domain) {
-               goto skip_domain;
-       }
-
-       /*
-        * Check domain type for specific "pre-action".
-        */
-       switch (cmd_ctx->lsm->domain.type) {
-       case LTTNG_DOMAIN_KERNEL:
-               if (!is_root) {
-                       ret = LTTNG_ERR_NEED_ROOT_SESSIOND;
-                       goto error;
-               }
-
-               /* Kernel tracer check */
-               if (kernel_tracer_fd == -1) {
-                       /* Basically, load kernel tracer modules */
-                       ret = init_kernel_tracer();
-                       if (ret != 0) {
-                               goto error;
-                       }
-               }
-
-               /* Consumer is in an ERROR state. Report back to client */
-               if (uatomic_read(&kernel_consumerd_state) == CONSUMER_ERROR) {
-                       ret = LTTNG_ERR_NO_KERNCONSUMERD;
-                       goto error;
-               }
-
-               /* Need a session for kernel command */
-               if (need_tracing_session) {
-                       if (cmd_ctx->session->kernel_session == NULL) {
-                               ret = create_kernel_session(cmd_ctx->session);
-                               if (ret < 0) {
-                                       ret = LTTNG_ERR_KERN_SESS_FAIL;
-                                       goto error;
-                               }
-                       }
-
-                       /* Start the kernel consumer daemon */
-                       pthread_mutex_lock(&kconsumer_data.pid_mutex);
-                       if (kconsumer_data.pid == 0 &&
-                                       cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
-                               pthread_mutex_unlock(&kconsumer_data.pid_mutex);
-                               ret = start_consumerd(&kconsumer_data);
-                               if (ret < 0) {
-                                       ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
-                                       goto error;
-                               }
-                               uatomic_set(&kernel_consumerd_state, CONSUMER_STARTED);
-                       } else {
-                               pthread_mutex_unlock(&kconsumer_data.pid_mutex);
-                       }
-
-                       /*
-                        * The consumer was just spawned so we need to add the socket to
-                        * the consumer output of the session if exist.
-                        */
-                       ret = consumer_create_socket(&kconsumer_data,
-                                       cmd_ctx->session->kernel_session->consumer);
-                       if (ret < 0) {
-                               goto error;
-                       }
-               }
-
-               break;
-       case LTTNG_DOMAIN_JUL:
-       case LTTNG_DOMAIN_LOG4J:
-       case LTTNG_DOMAIN_PYTHON:
-       case LTTNG_DOMAIN_UST:
-       {
-               if (!ust_app_supported()) {
-                       ret = LTTNG_ERR_NO_UST;
-                       goto error;
-               }
-               /* Consumer is in an ERROR state. Report back to client */
-               if (uatomic_read(&ust_consumerd_state) == CONSUMER_ERROR) {
-                       ret = LTTNG_ERR_NO_USTCONSUMERD;
-                       goto error;
-               }
-
-               if (need_tracing_session) {
-                       /* Create UST session if none exist. */
-                       if (cmd_ctx->session->ust_session == NULL) {
-                               ret = create_ust_session(cmd_ctx->session,
-                                               &cmd_ctx->lsm->domain);
-                               if (ret != LTTNG_OK) {
-                                       goto error;
-                               }
-                       }
-
-                       /* Start the UST consumer daemons */
-                       /* 64-bit */
-                       pthread_mutex_lock(&ustconsumer64_data.pid_mutex);
-                       if (config.consumerd64_bin_path.value &&
-                                       ustconsumer64_data.pid == 0 &&
-                                       cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
-                               pthread_mutex_unlock(&ustconsumer64_data.pid_mutex);
-                               ret = start_consumerd(&ustconsumer64_data);
-                               if (ret < 0) {
-                                       ret = LTTNG_ERR_UST_CONSUMER64_FAIL;
-                                       uatomic_set(&ust_consumerd64_fd, -EINVAL);
-                                       goto error;
-                               }
-
-                               uatomic_set(&ust_consumerd64_fd, ustconsumer64_data.cmd_sock);
-                               uatomic_set(&ust_consumerd_state, CONSUMER_STARTED);
-                       } else {
-                               pthread_mutex_unlock(&ustconsumer64_data.pid_mutex);
-                       }
-
-                       /*
-                        * Setup socket for consumer 64 bit. No need for atomic access
-                        * since it was set above and can ONLY be set in this thread.
-                        */
-                       ret = consumer_create_socket(&ustconsumer64_data,
-                                       cmd_ctx->session->ust_session->consumer);
-                       if (ret < 0) {
-                               goto error;
-                       }
-
-                       /* 32-bit */
-                       pthread_mutex_lock(&ustconsumer32_data.pid_mutex);
-                       if (config.consumerd32_bin_path.value &&
-                                       ustconsumer32_data.pid == 0 &&
-                                       cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
-                               pthread_mutex_unlock(&ustconsumer32_data.pid_mutex);
-                               ret = start_consumerd(&ustconsumer32_data);
-                               if (ret < 0) {
-                                       ret = LTTNG_ERR_UST_CONSUMER32_FAIL;
-                                       uatomic_set(&ust_consumerd32_fd, -EINVAL);
-                                       goto error;
-                               }
-
-                               uatomic_set(&ust_consumerd32_fd, ustconsumer32_data.cmd_sock);
-                               uatomic_set(&ust_consumerd_state, CONSUMER_STARTED);
-                       } else {
-                               pthread_mutex_unlock(&ustconsumer32_data.pid_mutex);
-                       }
-
-                       /*
-                        * Setup socket for consumer 32 bit. No need for atomic access
-                        * since it was set above and can ONLY be set in this thread.
-                        */
-                       ret = consumer_create_socket(&ustconsumer32_data,
-                                       cmd_ctx->session->ust_session->consumer);
-                       if (ret < 0) {
-                               goto error;
-                       }
-               }
-               break;
-       }
-       default:
-               break;
-       }
-skip_domain:
-
-       /* Validate consumer daemon state when start/stop trace command */
-       if (cmd_ctx->lsm->cmd_type == LTTNG_START_TRACE ||
-                       cmd_ctx->lsm->cmd_type == LTTNG_STOP_TRACE) {
-               switch (cmd_ctx->lsm->domain.type) {
-               case LTTNG_DOMAIN_NONE:
-                       break;
-               case LTTNG_DOMAIN_JUL:
-               case LTTNG_DOMAIN_LOG4J:
-               case LTTNG_DOMAIN_PYTHON:
-               case LTTNG_DOMAIN_UST:
-                       if (uatomic_read(&ust_consumerd_state) != CONSUMER_STARTED) {
-                               ret = LTTNG_ERR_NO_USTCONSUMERD;
-                               goto error;
-                       }
-                       break;
-               case LTTNG_DOMAIN_KERNEL:
-                       if (uatomic_read(&kernel_consumerd_state) != CONSUMER_STARTED) {
-                               ret = LTTNG_ERR_NO_KERNCONSUMERD;
-                               goto error;
-                       }
-                       break;
-               default:
-                       ret = LTTNG_ERR_UNKNOWN_DOMAIN;
-                       goto error;
-               }
-       }
-
-       /*
-        * Check that the UID or GID match that of the tracing session.
-        * The root user can interact with all sessions.
-        */
-       if (need_tracing_session) {
-               if (!session_access_ok(cmd_ctx->session,
-                               LTTNG_SOCK_GET_UID_CRED(&cmd_ctx->creds),
-                               LTTNG_SOCK_GET_GID_CRED(&cmd_ctx->creds)) ||
-                               cmd_ctx->session->destroyed) {
-                       ret = LTTNG_ERR_EPERM;
-                       goto error;
-               }
-       }
-
-       /*
-        * Send relayd information to consumer as soon as we have a domain and a
-        * session defined.
-        */
-       if (cmd_ctx->session && need_domain) {
-               /*
-                * Setup relayd if not done yet. If the relayd information was already
-                * sent to the consumer, this call will gracefully return.
-                */
-               ret = cmd_setup_relayd(cmd_ctx->session);
-               if (ret != LTTNG_OK) {
-                       goto error;
-               }
-       }
-
-       /* Process by command type */
-       switch (cmd_ctx->lsm->cmd_type) {
-       case LTTNG_ADD_CONTEXT:
-       {
-               /*
-                * An LTTNG_ADD_CONTEXT command might have a supplementary
-                * payload if the context being added is an application context.
-                */
-               if (cmd_ctx->lsm->u.context.ctx.ctx ==
-                               LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
-                       char *provider_name = NULL, *context_name = NULL;
-                       size_t provider_name_len =
-                                       cmd_ctx->lsm->u.context.provider_name_len;
-                       size_t context_name_len =
-                                       cmd_ctx->lsm->u.context.context_name_len;
-
-                       if (provider_name_len == 0 || context_name_len == 0) {
-                               /*
-                                * Application provider and context names MUST
-                                * be provided.
-                                */
-                               ret = -LTTNG_ERR_INVALID;
-                               goto error;
-                       }
-
-                       provider_name = zmalloc(provider_name_len + 1);
-                       if (!provider_name) {
-                               ret = -LTTNG_ERR_NOMEM;
-                               goto error;
-                       }
-                       cmd_ctx->lsm->u.context.ctx.u.app_ctx.provider_name =
-                                       provider_name;
-
-                       context_name = zmalloc(context_name_len + 1);
-                       if (!context_name) {
-                               ret = -LTTNG_ERR_NOMEM;
-                               goto error_add_context;
-                       }
-                       cmd_ctx->lsm->u.context.ctx.u.app_ctx.ctx_name =
-                                       context_name;
-
-                       ret = lttcomm_recv_unix_sock(sock, provider_name,
-                                       provider_name_len);
-                       if (ret < 0) {
-                               goto error_add_context;
-                       }
-
-                       ret = lttcomm_recv_unix_sock(sock, context_name,
-                                       context_name_len);
-                       if (ret < 0) {
-                               goto error_add_context;
-                       }
-               }
-
-               /*
-                * cmd_add_context assumes ownership of the provider and context
-                * names.
-                */
-               ret = cmd_add_context(cmd_ctx->session,
-                               cmd_ctx->lsm->domain.type,
-                               cmd_ctx->lsm->u.context.channel_name,
-                               &cmd_ctx->lsm->u.context.ctx,
-                               kernel_poll_pipe[1]);
-
-               cmd_ctx->lsm->u.context.ctx.u.app_ctx.provider_name = NULL;
-               cmd_ctx->lsm->u.context.ctx.u.app_ctx.ctx_name = NULL;
-error_add_context:
-               free(cmd_ctx->lsm->u.context.ctx.u.app_ctx.provider_name);
-               free(cmd_ctx->lsm->u.context.ctx.u.app_ctx.ctx_name);
-               if (ret < 0) {
-                       goto error;
-               }
-               break;
-       }
-       case LTTNG_DISABLE_CHANNEL:
-       {
-               ret = cmd_disable_channel(cmd_ctx->session, cmd_ctx->lsm->domain.type,
-                               cmd_ctx->lsm->u.disable.channel_name);
-               break;
-       }
-       case LTTNG_DISABLE_EVENT:
-       {
-
-               /*
-                * FIXME: handle filter; for now we just receive the filter's
-                * bytecode along with the filter expression which are sent by
-                * liblttng-ctl and discard them.
-                *
-                * This fixes an issue where the client may block while sending
-                * the filter payload and encounter an error because the session
-                * daemon closes the socket without ever handling this data.
-                */
-               size_t count = cmd_ctx->lsm->u.disable.expression_len +
-                       cmd_ctx->lsm->u.disable.bytecode_len;
-
-               if (count) {
-                       char data[LTTNG_FILTER_MAX_LEN];
-
-                       DBG("Discarding disable event command payload of size %zu", count);
-                       while (count) {
-                               ret = lttcomm_recv_unix_sock(sock, data,
-                                       count > sizeof(data) ? sizeof(data) : count);
-                               if (ret < 0) {
-                                       goto error;
-                               }
-
-                               count -= (size_t) ret;
-                       }
-               }
-               /* FIXME: passing packed structure to non-packed pointer */
-               ret = cmd_disable_event(cmd_ctx->session, cmd_ctx->lsm->domain.type,
-                               cmd_ctx->lsm->u.disable.channel_name,
-                               &cmd_ctx->lsm->u.disable.event);
-               break;
-       }
-       case LTTNG_ENABLE_CHANNEL:
-       {
-               cmd_ctx->lsm->u.channel.chan.attr.extended.ptr =
-                               (struct lttng_channel_extended *) &cmd_ctx->lsm->u.channel.extended;
-               ret = cmd_enable_channel(cmd_ctx->session, &cmd_ctx->lsm->domain,
-                               &cmd_ctx->lsm->u.channel.chan,
-                               kernel_poll_pipe[1]);
-               break;
-       }
-       case LTTNG_TRACK_PID:
-       {
-               ret = cmd_track_pid(cmd_ctx->session,
-                               cmd_ctx->lsm->domain.type,
-                               cmd_ctx->lsm->u.pid_tracker.pid);
-               break;
-       }
-       case LTTNG_UNTRACK_PID:
-       {
-               ret = cmd_untrack_pid(cmd_ctx->session,
-                               cmd_ctx->lsm->domain.type,
-                               cmd_ctx->lsm->u.pid_tracker.pid);
-               break;
-       }
-       case LTTNG_ENABLE_EVENT:
-       {
-               struct lttng_event *ev = NULL;
-               struct lttng_event_exclusion *exclusion = NULL;
-               struct lttng_filter_bytecode *bytecode = NULL;
-               char *filter_expression = NULL;
-
-               /* Handle exclusion events and receive it from the client. */
-               if (cmd_ctx->lsm->u.enable.exclusion_count > 0) {
-                       size_t count = cmd_ctx->lsm->u.enable.exclusion_count;
-
-                       exclusion = zmalloc(sizeof(struct lttng_event_exclusion) +
-                                       (count * LTTNG_SYMBOL_NAME_LEN));
-                       if (!exclusion) {
-                               ret = LTTNG_ERR_EXCLUSION_NOMEM;
-                               goto error;
-                       }
-
-                       DBG("Receiving var len exclusion event list from client ...");
-                       exclusion->count = count;
-                       ret = lttcomm_recv_unix_sock(sock, exclusion->names,
-                                       count * LTTNG_SYMBOL_NAME_LEN);
-                       if (ret <= 0) {
-                               DBG("Nothing recv() from client var len data... continuing");
-                               *sock_error = 1;
-                               free(exclusion);
-                               ret = LTTNG_ERR_EXCLUSION_INVAL;
-                               goto error;
-                       }
-               }
-
-               /* Get filter expression from client. */
-               if (cmd_ctx->lsm->u.enable.expression_len > 0) {
-                       size_t expression_len =
-                               cmd_ctx->lsm->u.enable.expression_len;
-
-                       if (expression_len > LTTNG_FILTER_MAX_LEN) {
-                               ret = LTTNG_ERR_FILTER_INVAL;
-                               free(exclusion);
-                               goto error;
-                       }
-
-                       filter_expression = zmalloc(expression_len);
-                       if (!filter_expression) {
-                               free(exclusion);
-                               ret = LTTNG_ERR_FILTER_NOMEM;
-                               goto error;
-                       }
-
-                       /* Receive var. len. data */
-                       DBG("Receiving var len filter's expression from client ...");
-                       ret = lttcomm_recv_unix_sock(sock, filter_expression,
-                               expression_len);
-                       if (ret <= 0) {
-                               DBG("Nothing recv() from client var len data... continuing");
-                               *sock_error = 1;
-                               free(filter_expression);
-                               free(exclusion);
-                               ret = LTTNG_ERR_FILTER_INVAL;
-                               goto error;
-                       }
-               }
-
-               /* Handle filter and get bytecode from client. */
-               if (cmd_ctx->lsm->u.enable.bytecode_len > 0) {
-                       size_t bytecode_len = cmd_ctx->lsm->u.enable.bytecode_len;
-
-                       if (bytecode_len > LTTNG_FILTER_MAX_LEN) {
-                               ret = LTTNG_ERR_FILTER_INVAL;
-                               free(filter_expression);
-                               free(exclusion);
-                               goto error;
-                       }
-
-                       bytecode = zmalloc(bytecode_len);
-                       if (!bytecode) {
-                               free(filter_expression);
-                               free(exclusion);
-                               ret = LTTNG_ERR_FILTER_NOMEM;
-                               goto error;
-                       }
-
-                       /* Receive var. len. data */
-                       DBG("Receiving var len filter's bytecode from client ...");
-                       ret = lttcomm_recv_unix_sock(sock, bytecode, bytecode_len);
-                       if (ret <= 0) {
-                               DBG("Nothing recv() from client var len data... continuing");
-                               *sock_error = 1;
-                               free(filter_expression);
-                               free(bytecode);
-                               free(exclusion);
-                               ret = LTTNG_ERR_FILTER_INVAL;
-                               goto error;
-                       }
-
-                       if ((bytecode->len + sizeof(*bytecode)) != bytecode_len) {
-                               free(filter_expression);
-                               free(bytecode);
-                               free(exclusion);
-                               ret = LTTNG_ERR_FILTER_INVAL;
-                               goto error;
-                       }
-               }
-
-               ev = lttng_event_copy(&cmd_ctx->lsm->u.enable.event);
-               if (!ev) {
-                       DBG("Failed to copy event: %s",
-                                       cmd_ctx->lsm->u.enable.event.name);
-                       free(filter_expression);
-                       free(bytecode);
-                       free(exclusion);
-                       ret = LTTNG_ERR_NOMEM;
-                       goto error;
-               }
-
-
-               if (cmd_ctx->lsm->u.enable.userspace_probe_location_len > 0) {
-                       /* Expect a userspace probe description. */
-                       ret = receive_userspace_probe(cmd_ctx, sock, sock_error, ev);
-                       if (ret) {
-                               free(filter_expression);
-                               free(bytecode);
-                               free(exclusion);
-                               lttng_event_destroy(ev);
-                               goto error;
-                       }
-               }
-
-               ret = cmd_enable_event(cmd_ctx->session, &cmd_ctx->lsm->domain,
-                               cmd_ctx->lsm->u.enable.channel_name,
-                               ev,
-                               filter_expression, bytecode, exclusion,
-                               kernel_poll_pipe[1]);
-               lttng_event_destroy(ev);
-               break;
-       }
-       case LTTNG_LIST_TRACEPOINTS:
-       {
-               struct lttng_event *events;
-               ssize_t nb_events;
-
-               session_lock_list();
-               nb_events = cmd_list_tracepoints(cmd_ctx->lsm->domain.type, &events);
-               session_unlock_list();
-               if (nb_events < 0) {
-                       /* Return value is a negative lttng_error_code. */
-                       ret = -nb_events;
-                       goto error;
-               }
-
-               /*
-                * Setup lttng message with payload size set to the event list size in
-                * bytes and then copy list into the llm payload.
-                */
-               ret = setup_lttng_msg_no_cmd_header(cmd_ctx, events,
-                       sizeof(struct lttng_event) * nb_events);
-               free(events);
-
-               if (ret < 0) {
-                       goto setup_error;
-               }
-
-               ret = LTTNG_OK;
-               break;
-       }
-       case LTTNG_LIST_TRACEPOINT_FIELDS:
-       {
-               struct lttng_event_field *fields;
-               ssize_t nb_fields;
-
-               session_lock_list();
-               nb_fields = cmd_list_tracepoint_fields(cmd_ctx->lsm->domain.type,
-                               &fields);
-               session_unlock_list();
-               if (nb_fields < 0) {
-                       /* Return value is a negative lttng_error_code. */
-                       ret = -nb_fields;
-                       goto error;
-               }
-
-               /*
-                * Setup lttng message with payload size set to the event list size in
-                * bytes and then copy list into the llm payload.
-                */
-               ret = setup_lttng_msg_no_cmd_header(cmd_ctx, fields,
-                               sizeof(struct lttng_event_field) * nb_fields);
-               free(fields);
-
-               if (ret < 0) {
-                       goto setup_error;
-               }
-
-               ret = LTTNG_OK;
-               break;
-       }
-       case LTTNG_LIST_SYSCALLS:
-       {
-               struct lttng_event *events;
-               ssize_t nb_events;
-
-               nb_events = cmd_list_syscalls(&events);
-               if (nb_events < 0) {
-                       /* Return value is a negative lttng_error_code. */
-                       ret = -nb_events;
-                       goto error;
-               }
-
-               /*
-                * Setup lttng message with payload size set to the event list size in
-                * bytes and then copy list into the llm payload.
-                */
-               ret = setup_lttng_msg_no_cmd_header(cmd_ctx, events,
-                       sizeof(struct lttng_event) * nb_events);
-               free(events);
-
-               if (ret < 0) {
-                       goto setup_error;
-               }
-
-               ret = LTTNG_OK;
-               break;
-       }
-       case LTTNG_LIST_TRACKER_PIDS:
-       {
-               int32_t *pids = NULL;
-               ssize_t nr_pids;
-
-               nr_pids = cmd_list_tracker_pids(cmd_ctx->session,
-                               cmd_ctx->lsm->domain.type, &pids);
-               if (nr_pids < 0) {
-                       /* Return value is a negative lttng_error_code. */
-                       ret = -nr_pids;
-                       goto error;
-               }
-
-               /*
-                * Setup lttng message with payload size set to the event list size in
-                * bytes and then copy list into the llm payload.
-                */
-               ret = setup_lttng_msg_no_cmd_header(cmd_ctx, pids,
-                       sizeof(int32_t) * nr_pids);
-               free(pids);
-
-               if (ret < 0) {
-                       goto setup_error;
-               }
-
-               ret = LTTNG_OK;
-               break;
-       }
-       case LTTNG_SET_CONSUMER_URI:
-       {
-               size_t nb_uri, len;
-               struct lttng_uri *uris;
-
-               nb_uri = cmd_ctx->lsm->u.uri.size;
-               len = nb_uri * sizeof(struct lttng_uri);
-
-               if (nb_uri == 0) {
-                       ret = LTTNG_ERR_INVALID;
-                       goto error;
-               }
-
-               uris = zmalloc(len);
-               if (uris == NULL) {
-                       ret = LTTNG_ERR_FATAL;
-                       goto error;
-               }
-
-               /* Receive variable len data */
-               DBG("Receiving %zu URI(s) from client ...", nb_uri);
-               ret = lttcomm_recv_unix_sock(sock, uris, len);
-               if (ret <= 0) {
-                       DBG("No URIs received from client... continuing");
-                       *sock_error = 1;
-                       ret = LTTNG_ERR_SESSION_FAIL;
-                       free(uris);
-                       goto error;
-               }
-
-               ret = cmd_set_consumer_uri(cmd_ctx->session, nb_uri, uris);
-               free(uris);
-               if (ret != LTTNG_OK) {
-                       goto error;
-               }
-
-
-               break;
-       }
-       case LTTNG_START_TRACE:
-       {
-               /*
-                * On the first start, if we have a kernel session and we have
-                * enabled time or size-based rotations, we have to make sure
-                * the kernel tracer supports it.
-                */
-               if (!cmd_ctx->session->has_been_started && \
-                               cmd_ctx->session->kernel_session && \
-                               (cmd_ctx->session->rotate_timer_period || \
-                                       cmd_ctx->session->rotate_size) && \
-                               !check_rotate_compatible()) {
-                       DBG("Kernel tracer version is not compatible with the rotation feature");
-                       ret = LTTNG_ERR_ROTATION_WRONG_VERSION;
-                       goto error;
-               }
-               ret = cmd_start_trace(cmd_ctx->session);
-               break;
-       }
-       case LTTNG_STOP_TRACE:
-       {
-               ret = cmd_stop_trace(cmd_ctx->session);
-               break;
-       }
-       case LTTNG_CREATE_SESSION:
-       {
-               size_t nb_uri, len;
-               struct lttng_uri *uris = NULL;
-
-               nb_uri = cmd_ctx->lsm->u.uri.size;
-               len = nb_uri * sizeof(struct lttng_uri);
-
-               if (nb_uri > 0) {
-                       uris = zmalloc(len);
-                       if (uris == NULL) {
-                               ret = LTTNG_ERR_FATAL;
-                               goto error;
-                       }
-
-                       /* Receive variable len data */
-                       DBG("Waiting for %zu URIs from client ...", nb_uri);
-                       ret = lttcomm_recv_unix_sock(sock, uris, len);
-                       if (ret <= 0) {
-                               DBG("No URIs received from client... continuing");
-                               *sock_error = 1;
-                               ret = LTTNG_ERR_SESSION_FAIL;
-                               free(uris);
-                               goto error;
-                       }
-
-                       if (nb_uri == 1 && uris[0].dtype != LTTNG_DST_PATH) {
-                               DBG("Creating session with ONE network URI is a bad call");
-                               ret = LTTNG_ERR_SESSION_FAIL;
-                               free(uris);
-                               goto error;
-                       }
-               }
-
-               ret = cmd_create_session_uri(cmd_ctx->lsm->session.name, uris, nb_uri,
-                       &cmd_ctx->creds, 0);
-
-               free(uris);
-
-               break;
-       }
-       case LTTNG_DESTROY_SESSION:
-       {
-               ret = cmd_destroy_session(cmd_ctx->session,
-                               notification_thread_handle);
-               break;
-       }
-       case LTTNG_LIST_DOMAINS:
-       {
-               ssize_t nb_dom;
-               struct lttng_domain *domains = NULL;
-
-               nb_dom = cmd_list_domains(cmd_ctx->session, &domains);
-               if (nb_dom < 0) {
-                       /* Return value is a negative lttng_error_code. */
-                       ret = -nb_dom;
-                       goto error;
-               }
-
-               ret = setup_lttng_msg_no_cmd_header(cmd_ctx, domains,
-                       nb_dom * sizeof(struct lttng_domain));
-               free(domains);
-
-               if (ret < 0) {
-                       goto setup_error;
-               }
-
-               ret = LTTNG_OK;
-               break;
-       }
-       case LTTNG_LIST_CHANNELS:
-       {
-               ssize_t payload_size;
-               struct lttng_channel *channels = NULL;
-
-               payload_size = cmd_list_channels(cmd_ctx->lsm->domain.type,
-                               cmd_ctx->session, &channels);
-               if (payload_size < 0) {
-                       /* Return value is a negative lttng_error_code. */
-                       ret = -payload_size;
-                       goto error;
-               }
-
-               ret = setup_lttng_msg_no_cmd_header(cmd_ctx, channels,
-                       payload_size);
-               free(channels);
-
-               if (ret < 0) {
-                       goto setup_error;
-               }
-
-               ret = LTTNG_OK;
-               break;
-       }
-       case LTTNG_LIST_EVENTS:
-       {
-               ssize_t nb_event;
-               struct lttng_event *events = NULL;
-               struct lttcomm_event_command_header cmd_header;
-               size_t total_size;
-
-               memset(&cmd_header, 0, sizeof(cmd_header));
-               /* Extended infos are included at the end of events */
-               nb_event = cmd_list_events(cmd_ctx->lsm->domain.type,
-                       cmd_ctx->session, cmd_ctx->lsm->u.list.channel_name,
-                       &events, &total_size);
-
-               if (nb_event < 0) {
-                       /* Return value is a negative lttng_error_code. */
-                       ret = -nb_event;
-                       goto error;
-               }
-
-               cmd_header.nb_events = nb_event;
-               ret = setup_lttng_msg(cmd_ctx, events, total_size,
-                       &cmd_header, sizeof(cmd_header));
-               free(events);
-
-               if (ret < 0) {
-                       goto setup_error;
-               }
-
-               ret = LTTNG_OK;
-               break;
-       }
-       case LTTNG_LIST_SESSIONS:
-       {
-               unsigned int nr_sessions;
-               void *sessions_payload;
-               size_t payload_len;
-
-               session_lock_list();
-               nr_sessions = lttng_sessions_count(
-                               LTTNG_SOCK_GET_UID_CRED(&cmd_ctx->creds),
-                               LTTNG_SOCK_GET_GID_CRED(&cmd_ctx->creds));
-               payload_len = sizeof(struct lttng_session) * nr_sessions;
-               sessions_payload = zmalloc(payload_len);
-
-               if (!sessions_payload) {
-                       session_unlock_list();
-                       ret = -ENOMEM;
-                       goto setup_error;
-               }
-
-               cmd_list_lttng_sessions(sessions_payload,
-                       LTTNG_SOCK_GET_UID_CRED(&cmd_ctx->creds),
-                       LTTNG_SOCK_GET_GID_CRED(&cmd_ctx->creds));
-               session_unlock_list();
-
-               ret = setup_lttng_msg_no_cmd_header(cmd_ctx, sessions_payload,
-                       payload_len);
-               free(sessions_payload);
-
-               if (ret < 0) {
-                       goto setup_error;
-               }
-
-               ret = LTTNG_OK;
-               break;
-       }
-       case LTTNG_REGISTER_CONSUMER:
-       {
-               struct consumer_data *cdata;
-
-               switch (cmd_ctx->lsm->domain.type) {
-               case LTTNG_DOMAIN_KERNEL:
-                       cdata = &kconsumer_data;
-                       break;
-               default:
-                       ret = LTTNG_ERR_UND;
-                       goto error;
-               }
-
-               ret = cmd_register_consumer(cmd_ctx->session, cmd_ctx->lsm->domain.type,
-                               cmd_ctx->lsm->u.reg.path, cdata);
-               break;
-       }
-       case LTTNG_DATA_PENDING:
-       {
-               int pending_ret;
-               uint8_t pending_ret_byte;
-
-               pending_ret = cmd_data_pending(cmd_ctx->session);
-
-               /*
-                * FIXME
-                *
-                * This function may returns 0 or 1 to indicate whether or not
-                * there is data pending. In case of error, it should return an
-                * LTTNG_ERR code. However, some code paths may still return
-                * a nondescript error code, which we handle by returning an
-                * "unknown" error.
-                */
-               if (pending_ret == 0 || pending_ret == 1) {
-                       /*
-                        * ret will be set to LTTNG_OK at the end of
-                        * this function.
-                        */
-               } else if (pending_ret < 0) {
-                       ret = LTTNG_ERR_UNK;
-                       goto setup_error;
-               } else {
-                       ret = pending_ret;
-                       goto setup_error;
-               }
-
-               pending_ret_byte = (uint8_t) pending_ret;
-
-               /* 1 byte to return whether or not data is pending */
-               ret = setup_lttng_msg_no_cmd_header(cmd_ctx,
-                       &pending_ret_byte, 1);
-
-               if (ret < 0) {
-                       goto setup_error;
-               }
-
-               ret = LTTNG_OK;
-               break;
-       }
-       case LTTNG_SNAPSHOT_ADD_OUTPUT:
-       {
-               struct lttcomm_lttng_output_id reply;
-
-               ret = cmd_snapshot_add_output(cmd_ctx->session,
-                               &cmd_ctx->lsm->u.snapshot_output.output, &reply.id);
-               if (ret != LTTNG_OK) {
-                       goto error;
-               }
-
-               ret = setup_lttng_msg_no_cmd_header(cmd_ctx, &reply,
-                       sizeof(reply));
-               if (ret < 0) {
-                       goto setup_error;
-               }
-
-               /* Copy output list into message payload */
-               ret = LTTNG_OK;
-               break;
-       }
-       case LTTNG_SNAPSHOT_DEL_OUTPUT:
-       {
-               ret = cmd_snapshot_del_output(cmd_ctx->session,
-                               &cmd_ctx->lsm->u.snapshot_output.output);
-               break;
-       }
-       case LTTNG_SNAPSHOT_LIST_OUTPUT:
-       {
-               ssize_t nb_output;
-               struct lttng_snapshot_output *outputs = NULL;
-
-               nb_output = cmd_snapshot_list_outputs(cmd_ctx->session, &outputs);
-               if (nb_output < 0) {
-                       ret = -nb_output;
-                       goto error;
-               }
-
-               assert((nb_output > 0 && outputs) || nb_output == 0);
-               ret = setup_lttng_msg_no_cmd_header(cmd_ctx, outputs,
-                               nb_output * sizeof(struct lttng_snapshot_output));
-               free(outputs);
-
-               if (ret < 0) {
-                       goto setup_error;
-               }
-
-               ret = LTTNG_OK;
-               break;
-       }
-       case LTTNG_SNAPSHOT_RECORD:
-       {
-               ret = cmd_snapshot_record(cmd_ctx->session,
-                               &cmd_ctx->lsm->u.snapshot_record.output,
-                               cmd_ctx->lsm->u.snapshot_record.wait);
-               break;
-       }
-       case LTTNG_CREATE_SESSION_SNAPSHOT:
-       {
-               size_t nb_uri, len;
-               struct lttng_uri *uris = NULL;
-
-               nb_uri = cmd_ctx->lsm->u.uri.size;
-               len = nb_uri * sizeof(struct lttng_uri);
-
-               if (nb_uri > 0) {
-                       uris = zmalloc(len);
-                       if (uris == NULL) {
-                               ret = LTTNG_ERR_FATAL;
-                               goto error;
-                       }
-
-                       /* Receive variable len data */
-                       DBG("Waiting for %zu URIs from client ...", nb_uri);
-                       ret = lttcomm_recv_unix_sock(sock, uris, len);
-                       if (ret <= 0) {
-                               DBG("No URIs received from client... continuing");
-                               *sock_error = 1;
-                               ret = LTTNG_ERR_SESSION_FAIL;
-                               free(uris);
-                               goto error;
-                       }
-
-                       if (nb_uri == 1 && uris[0].dtype != LTTNG_DST_PATH) {
-                               DBG("Creating session with ONE network URI is a bad call");
-                               ret = LTTNG_ERR_SESSION_FAIL;
-                               free(uris);
-                               goto error;
-                       }
-               }
-
-               ret = cmd_create_session_snapshot(cmd_ctx->lsm->session.name, uris,
-                               nb_uri, &cmd_ctx->creds);
-               free(uris);
-               break;
-       }
-       case LTTNG_CREATE_SESSION_LIVE:
-       {
-               size_t nb_uri, len;
-               struct lttng_uri *uris = NULL;
-
-               nb_uri = cmd_ctx->lsm->u.uri.size;
-               len = nb_uri * sizeof(struct lttng_uri);
-
-               if (nb_uri > 0) {
-                       uris = zmalloc(len);
-                       if (uris == NULL) {
-                               ret = LTTNG_ERR_FATAL;
-                               goto error;
-                       }
-
-                       /* Receive variable len data */
-                       DBG("Waiting for %zu URIs from client ...", nb_uri);
-                       ret = lttcomm_recv_unix_sock(sock, uris, len);
-                       if (ret <= 0) {
-                               DBG("No URIs received from client... continuing");
-                               *sock_error = 1;
-                               ret = LTTNG_ERR_SESSION_FAIL;
-                               free(uris);
-                               goto error;
-                       }
-
-                       if (nb_uri == 1 && uris[0].dtype != LTTNG_DST_PATH) {
-                               DBG("Creating session with ONE network URI is a bad call");
-                               ret = LTTNG_ERR_SESSION_FAIL;
-                               free(uris);
-                               goto error;
-                       }
-               }
-
-               ret = cmd_create_session_uri(cmd_ctx->lsm->session.name, uris,
-                               nb_uri, &cmd_ctx->creds, cmd_ctx->lsm->u.session_live.timer_interval);
-               free(uris);
-               break;
-       }
-       case LTTNG_SAVE_SESSION:
-       {
-               ret = cmd_save_sessions(&cmd_ctx->lsm->u.save_session.attr,
-                       &cmd_ctx->creds);
-               break;
-       }
-       case LTTNG_SET_SESSION_SHM_PATH:
-       {
-               ret = cmd_set_session_shm_path(cmd_ctx->session,
-                               cmd_ctx->lsm->u.set_shm_path.shm_path);
-               break;
-       }
-       case LTTNG_REGENERATE_METADATA:
-       {
-               ret = cmd_regenerate_metadata(cmd_ctx->session);
-               break;
-       }
-       case LTTNG_REGENERATE_STATEDUMP:
-       {
-               ret = cmd_regenerate_statedump(cmd_ctx->session);
-               break;
-       }
-       case LTTNG_REGISTER_TRIGGER:
-       {
-               ret = cmd_register_trigger(cmd_ctx, sock,
-                               notification_thread_handle);
-               break;
-       }
-       case LTTNG_UNREGISTER_TRIGGER:
-       {
-               ret = cmd_unregister_trigger(cmd_ctx, sock,
-                               notification_thread_handle);
-               break;
-       }
-       case LTTNG_ROTATE_SESSION:
-       {
-               struct lttng_rotate_session_return rotate_return;
-
-               DBG("Client rotate session \"%s\"", cmd_ctx->session->name);
-
-               memset(&rotate_return, 0, sizeof(rotate_return));
-               if (cmd_ctx->session->kernel_session && !check_rotate_compatible()) {
-                       DBG("Kernel tracer version is not compatible with the rotation feature");
-                       ret = LTTNG_ERR_ROTATION_WRONG_VERSION;
-                       goto error;
-               }
-
-               ret = cmd_rotate_session(cmd_ctx->session, &rotate_return);
-               if (ret < 0) {
-                       ret = -ret;
-                       goto error;
-               }
-
-               ret = setup_lttng_msg_no_cmd_header(cmd_ctx, &rotate_return,
-                               sizeof(rotate_return));
-               if (ret < 0) {
-                       ret = -ret;
-                       goto error;
-               }
-
-               ret = LTTNG_OK;
-               break;
-       }
-       case LTTNG_ROTATION_GET_INFO:
-       {
-               struct lttng_rotation_get_info_return get_info_return;
-
-               memset(&get_info_return, 0, sizeof(get_info_return));
-               ret = cmd_rotate_get_info(cmd_ctx->session, &get_info_return,
-                               cmd_ctx->lsm->u.get_rotation_info.rotation_id);
-               if (ret < 0) {
-                       ret = -ret;
-                       goto error;
-               }
-
-               ret = setup_lttng_msg_no_cmd_header(cmd_ctx, &get_info_return,
-                               sizeof(get_info_return));
-               if (ret < 0) {
-                       ret = -ret;
-                       goto error;
-               }
-
-               ret = LTTNG_OK;
-               break;
-       }
-       case LTTNG_ROTATION_SET_SCHEDULE:
-       {
-               bool set_schedule;
-               enum lttng_rotation_schedule_type schedule_type;
-               uint64_t value;
-
-               if (cmd_ctx->session->kernel_session && !check_rotate_compatible()) {
-                       DBG("Kernel tracer version does not support session rotations");
-                       ret = LTTNG_ERR_ROTATION_WRONG_VERSION;
-                       goto error;
-               }
-
-               set_schedule = cmd_ctx->lsm->u.rotation_set_schedule.set == 1;
-               schedule_type = (enum lttng_rotation_schedule_type) cmd_ctx->lsm->u.rotation_set_schedule.type;
-               value = cmd_ctx->lsm->u.rotation_set_schedule.value;
-
-               ret = cmd_rotation_set_schedule(cmd_ctx->session,
-                               set_schedule,
-                               schedule_type,
-                               value,
-                               notification_thread_handle);
-               if (ret != LTTNG_OK) {
-                       goto error;
-               }
-
-               break;
-       }
-       case LTTNG_SESSION_LIST_ROTATION_SCHEDULES:
-       {
-               struct lttng_session_list_schedules_return schedules = {
-                       .periodic.set = !!cmd_ctx->session->rotate_timer_period,
-                       .periodic.value = cmd_ctx->session->rotate_timer_period,
-                       .size.set = !!cmd_ctx->session->rotate_size,
-                       .size.value = cmd_ctx->session->rotate_size,
-               };
-
-               ret = setup_lttng_msg_no_cmd_header(cmd_ctx, &schedules,
-                               sizeof(schedules));
-               if (ret < 0) {
-                       ret = -ret;
-                       goto error;
-               }
-
-               ret = LTTNG_OK;
-               break;
-       }
-       default:
-               ret = LTTNG_ERR_UND;
-               break;
-       }
-
-error:
-       if (cmd_ctx->llm == NULL) {
-               DBG("Missing llm structure. Allocating one.");
-               if (setup_lttng_msg_no_cmd_header(cmd_ctx, NULL, 0) < 0) {
-                       goto setup_error;
-               }
-       }
-       /* Set return code */
-       cmd_ctx->llm->ret_code = ret;
-setup_error:
-       if (cmd_ctx->session) {
-               session_unlock(cmd_ctx->session);
-               session_put(cmd_ctx->session);
-       }
-       if (need_tracing_session) {
-               session_unlock_list();
-       }
-init_setup_error:
-       assert(!rcu_read_ongoing());
-       return ret;
-}
-
-/*
- * This thread manage all clients request using the unix client socket for
- * communication.
- */
-static void *thread_manage_clients(void *data)
-{
-       int sock = -1, ret, i, pollfd, err = -1;
-       int sock_error;
-       uint32_t revents, nb_fd;
-       struct command_ctx *cmd_ctx = NULL;
-       struct lttng_poll_event events;
-
-       DBG("[thread] Manage client started");
-
-       rcu_register_thread();
-
-       health_register(health_sessiond, HEALTH_SESSIOND_TYPE_CMD);
-
-       health_code_update();
-
-       ret = lttcomm_listen_unix_sock(client_sock);
-       if (ret < 0) {
-               goto error_listen;
-       }
-
-       /*
-        * Pass 2 as size here for the thread quit pipe and client_sock. Nothing
-        * more will be added to this poll set.
-        */
-       ret = sessiond_set_thread_pollset(&events, 2);
-       if (ret < 0) {
-               goto error_create_poll;
-       }
-
-       /* Add the application registration socket */
-       ret = lttng_poll_add(&events, client_sock, LPOLLIN | LPOLLPRI);
-       if (ret < 0) {
-               goto error;
-       }
-
-       ret = sem_post(&load_info->message_thread_ready);
-       if (ret) {
-               PERROR("sem_post message_thread_ready");
-               goto error;
-       }
-
-       /*
-        * Wait until all support threads are initialized before accepting
-        * commands.
-        */
-       while (uatomic_read(&lttng_sessiond_ready) != 0) {
-               /*
-                * If a support thread failed to launch, it may signal that
-                * we must exit and the sessiond would never be marked as
-                * "ready".
-                *
-                * The timeout is set to 1ms, which serves as a way to
-                * pace down this check.
-                */
-               ret = sessiond_wait_for_quit_pipe(1000);
-               if (ret > 0) {
-                       goto exit;
-               }
-       }
-       /*
-        * This barrier is paired with the one in sessiond_notify_ready() to
-        * ensure that loads accessing data initialized by the other threads,
-        * on which this thread was waiting, are not performed before this point.
-        *
-        * Note that this could be a 'read' memory barrier, but a full barrier
-        * is used in case the code changes. The performance implications of
-        * this choice are minimal since this is a slow path.
-        */
-       cmm_smp_mb();
-
-       /* This testpoint is after we signal readiness to the parent. */
-       if (testpoint(sessiond_thread_manage_clients)) {
-               goto error;
-       }
-
-       if (testpoint(sessiond_thread_manage_clients_before_loop)) {
-               goto error;
-       }
-
-       health_code_update();
-
-       /* Set state as running. */
-       sessiond_set_client_thread_state(true);
-
-       while (1) {
-               const struct cmd_completion_handler *cmd_completion_handler;
-
-               DBG("Accepting client command ...");
-
-               /* Inifinite blocking call, waiting for transmission */
-       restart:
-               health_poll_entry();
-               ret = lttng_poll_wait(&events, -1);
-               health_poll_exit();
-               if (ret < 0) {
-                       /*
-                        * Restart interrupted system call.
-                        */
-                       if (errno == EINTR) {
-                               goto restart;
-                       }
-                       goto error;
-               }
-
-               nb_fd = ret;
-
-               for (i = 0; i < nb_fd; i++) {
-                       /* Fetch once the poll data */
-                       revents = LTTNG_POLL_GETEV(&events, i);
-                       pollfd = LTTNG_POLL_GETFD(&events, i);
-
-                       health_code_update();
-
-                       if (!revents) {
-                               /* No activity for this FD (poll implementation). */
-                               continue;
-                       }
-
-                       /* Thread quit pipe has been closed. Killing thread. */
-                       ret = sessiond_check_thread_quit_pipe(pollfd, revents);
-                       if (ret) {
-                               err = 0;
-                               goto exit;
-                       }
-
-                       /* Event on the registration socket */
-                       if (pollfd == client_sock) {
-                               if (revents & LPOLLIN) {
-                                       continue;
-                               } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
-                                       ERR("Client socket poll error");
-                                       goto error;
-                               } else {
-                                       ERR("Unexpected poll events %u for sock %d", revents, pollfd);
-                                       goto error;
-                               }
-                       }
-               }
-
-               DBG("Wait for client response");
-
-               health_code_update();
-
-               sock = lttcomm_accept_unix_sock(client_sock);
-               if (sock < 0) {
-                       goto error;
-               }
-
-               /*
-                * Set the CLOEXEC flag. Return code is useless because either way, the
-                * show must go on.
-                */
-               (void) utils_set_fd_cloexec(sock);
-
-               /* Set socket option for credentials retrieval */
-               ret = lttcomm_setsockopt_creds_unix_sock(sock);
-               if (ret < 0) {
-                       goto error;
-               }
-
-               /* Allocate context command to process the client request */
-               cmd_ctx = zmalloc(sizeof(struct command_ctx));
-               if (cmd_ctx == NULL) {
-                       PERROR("zmalloc cmd_ctx");
-                       goto error;
-               }
-
-               /* Allocate data buffer for reception */
-               cmd_ctx->lsm = zmalloc(sizeof(struct lttcomm_session_msg));
-               if (cmd_ctx->lsm == NULL) {
-                       PERROR("zmalloc cmd_ctx->lsm");
-                       goto error;
-               }
-
-               cmd_ctx->llm = NULL;
-               cmd_ctx->session = NULL;
-
-               health_code_update();
-
-               /*
-                * Data is received from the lttng client. The struct
-                * lttcomm_session_msg (lsm) contains the command and data request of
-                * the client.
-                */
-               DBG("Receiving data from client ...");
-               ret = lttcomm_recv_creds_unix_sock(sock, cmd_ctx->lsm,
-                               sizeof(struct lttcomm_session_msg), &cmd_ctx->creds);
-               if (ret <= 0) {
-                       DBG("Nothing recv() from client... continuing");
-                       ret = close(sock);
-                       if (ret) {
-                               PERROR("close");
-                       }
-                       sock = -1;
-                       clean_command_ctx(&cmd_ctx);
-                       continue;
-               }
-
-               health_code_update();
-
-               // TODO: Validate cmd_ctx including sanity check for
-               // security purpose.
-
-               rcu_thread_online();
-               /*
-                * This function dispatch the work to the kernel or userspace tracer
-                * libs and fill the lttcomm_lttng_msg data structure of all the needed
-                * informations for the client. The command context struct contains
-                * everything this function may needs.
-                */
-               ret = process_client_msg(cmd_ctx, sock, &sock_error);
-               rcu_thread_offline();
-               if (ret < 0) {
-                       ret = close(sock);
-                       if (ret) {
-                               PERROR("close");
-                       }
-                       sock = -1;
-                       /*
-                        * TODO: Inform client somehow of the fatal error. At
-                        * this point, ret < 0 means that a zmalloc failed
-                        * (ENOMEM). Error detected but still accept
-                        * command, unless a socket error has been
-                        * detected.
-                        */
-                       clean_command_ctx(&cmd_ctx);
-                       continue;
-               }
-
-               cmd_completion_handler = cmd_pop_completion_handler();
-               if (cmd_completion_handler) {
-                       enum lttng_error_code completion_code;
-
-                       completion_code = cmd_completion_handler->run(
-                                       cmd_completion_handler->data);
-                       if (completion_code != LTTNG_OK) {
-                               clean_command_ctx(&cmd_ctx);
-                               continue;
-                       }
-               }
-
-               health_code_update();
-
-               DBG("Sending response (size: %d, retcode: %s (%d))",
-                               cmd_ctx->lttng_msg_size,
-                               lttng_strerror(-cmd_ctx->llm->ret_code),
-                               cmd_ctx->llm->ret_code);
-               ret = send_unix_sock(sock, cmd_ctx->llm, cmd_ctx->lttng_msg_size);
-               if (ret < 0) {
-                       ERR("Failed to send data back to client");
-               }
-
-               /* End of transmission */
-               ret = close(sock);
-               if (ret) {
-                       PERROR("close");
-               }
-               sock = -1;
-
-               clean_command_ctx(&cmd_ctx);
-
-               health_code_update();
-       }
-
-exit:
-error:
-       if (sock >= 0) {
-               ret = close(sock);
-               if (ret) {
-                       PERROR("close");
-               }
-       }
-
-       lttng_poll_clean(&events);
-       clean_command_ctx(&cmd_ctx);
-
-error_listen:
-error_create_poll:
-       unlink(config.client_unix_sock_path.value);
-       if (client_sock >= 0) {
-               ret = close(client_sock);
-               if (ret) {
-                       PERROR("close");
-               }
-       }
-
-       if (err) {
-               health_error();
-               ERR("Health error occurred in %s", __func__);
-       }
-
-       health_unregister(health_sessiond);
-
-       DBG("Client thread dying");
-
-       rcu_unregister_thread();
-
-       /*
-        * Since we are creating the consumer threads, we own them, so we need
-        * to join them before our thread exits.
-        */
-       ret = join_consumer_thread(&kconsumer_data);
-       if (ret) {
-               errno = ret;
-               PERROR("join_consumer");
-       }
-
-       ret = join_consumer_thread(&ustconsumer32_data);
-       if (ret) {
-               errno = ret;
-               PERROR("join_consumer ust32");
-       }
-
-       ret = join_consumer_thread(&ustconsumer64_data);
-       if (ret) {
-               errno = ret;
-               PERROR("join_consumer ust64");
-       }
-
-       /* Set state as non-running. */
-       sessiond_set_client_thread_state(false);
-       return NULL;
-}
-
-static int string_match(const char *str1, const char *str2)
-{
-       return (str1 && str2) && !strcmp(str1, str2);
-}
-
-/*
- * Take an option from the getopt output and set it in the right variable to be
- * used later.
- *
- * Return 0 on success else a negative value.
- */
-static int set_option(int opt, const char *arg, const char *optname)
-{
-       int ret = 0;
+       int ret = 0;
 
        if (string_match(optname, "client-sock") || opt == 'c') {
                if (!arg || *arg == '\0') {
@@ -5030,9 +2512,7 @@ end:
 }
 
 /*
- * Creates the two needed socket by the daemon.
- *         apps_sock - The communication socket for all UST apps.
- *         client_sock - The communication of the cli tool (lttng).
+ * Creates the application socket.
  */
 static int init_daemon_socket(void)
 {
@@ -5041,30 +2521,6 @@ static int init_daemon_socket(void)
 
        old_umask = umask(0);
 
-       /* Create client tool unix socket */
-       client_sock = lttcomm_create_unix_sock(config.client_unix_sock_path.value);
-       if (client_sock < 0) {
-               ERR("Create unix sock failed: %s", config.client_unix_sock_path.value);
-               ret = -1;
-               goto end;
-       }
-
-       /* Set the cloexec flag */
-       ret = utils_set_fd_cloexec(client_sock);
-       if (ret < 0) {
-               ERR("Unable to set CLOEXEC flag to the client Unix socket (fd: %d). "
-                               "Continuing but note that the consumer daemon will have a "
-                               "reference to this socket on exec()", client_sock);
-       }
-
-       /* File permission MUST be 660 */
-       ret = chmod(config.client_unix_sock_path.value, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
-       if (ret < 0) {
-               ERR("Set file permissions failed: %s", config.client_unix_sock_path.value);
-               PERROR("chmod");
-               goto end;
-       }
-
        /* Create the application unix socket */
        apps_sock = lttcomm_create_unix_sock(config.apps_unix_sock_path.value);
        if (apps_sock < 0) {
@@ -5090,8 +2546,8 @@ static int init_daemon_socket(void)
                goto end;
        }
 
-       DBG3("Session daemon client socket %d and application socket %d created",
-                       client_sock, apps_sock);
+       DBG3("Session daemon application socket %d created",
+                       apps_sock);
 
 end:
        umask(old_umask);
@@ -5448,12 +2904,6 @@ static void destroy_all_sessions_and_wait(void)
                return;
        }
 
-       /*
-        * Ensure that the client thread is no longer accepting new commands,
-        * which could cause new sessions to be created.
-        */
-       sessiond_wait_client_thread_stopped();
-
        session_lock_list();
        /* Initiate the destruction of all sessions. */
        cds_list_for_each_entry_safe(session, tmp,
@@ -5497,6 +2947,7 @@ int main(int argc, char **argv)
        struct rotation_thread_handle *rotation_thread_handle = NULL;
        /* Queue of rotation jobs populated by the sessiond-timer. */
        struct rotation_thread_timer_queue *rotation_timer_queue = NULL;
+       struct lttng_thread *client_thread = NULL;
 
        init_kernel_workarounds();
 
@@ -5887,13 +3338,9 @@ int main(int argc, char **argv)
        }
 
        /* Create thread to manage the client socket */
-       ret = pthread_create(&client_thread, default_pthread_attr(),
-                       thread_manage_clients, (void *) NULL);
-       if (ret) {
-               errno = ret;
-               PERROR("pthread_create clients");
+       client_thread = launch_client_thread();
+       if (!client_thread) {
                retval = -1;
-               stop_threads();
                goto exit_client;
        }
 
@@ -5991,6 +3438,17 @@ int main(int argc, char **argv)
 
        /* Initiate teardown once activity occurs on the quit pipe. */
        sessiond_wait_for_quit_pipe(-1U);
+
+       /*
+        * Ensure that the client thread is no longer accepting new commands,
+        * which could cause new sessions to be created.
+        */
+       if (!lttng_thread_shutdown(client_thread)) {
+               ERR("Failed to shutdown the client thread, continuing teardown");
+               lttng_thread_put(client_thread);
+               client_thread = NULL;
+       }
+
        destroy_all_sessions_and_wait();
 exit_load_session:
 
@@ -6047,20 +3505,16 @@ exit_reg_apps:
                retval = -1;
        }
 exit_dispatch:
-
-       ret = pthread_join(client_thread, &status);
-       if (ret) {
-               errno = ret;
-               PERROR("pthread_join");
-               retval = -1;
-       }
-
 exit_client:
 exit_rotation:
 exit_notification:
        lttng_thread_list_shutdown_orphans();
 exit_health:
 exit_init_data:
+       if (client_thread) {
+               lttng_thread_put(client_thread);
+       }
+
        /*
         * Wait for all pending call_rcu work to complete before tearing
         * down data structures. call_rcu worker may be trying to
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