Fix: poll: show the correct number of fds
[lttng-tools.git] / src / bin / lttng-sessiond / main.c
index 6a918ec56a73926621a20119eb3e3686d0f3d998..2cf749a50b6257ac7acd3926073ebd5e66897dc3 100644 (file)
@@ -85,6 +85,7 @@ static char *opt_load_session_path;
 static pid_t ppid;          /* Parent PID for --sig-parent option */
 static pid_t child_ppid;    /* Internal parent PID use with daemonize. */
 static char *rundir;
+static int lockfile_fd = -1;
 
 /* Set to 1 when a SIGUSR1 signal is received. */
 static int recv_child_signal;
@@ -511,6 +512,27 @@ static void close_consumer_sockets(void)
        }
 }
 
+/*
+ * Generate the full lock file path using the rundir.
+ *
+ * Return the snprintf() return value thus a negative value is an error.
+ */
+static int generate_lock_file_path(char *path, size_t len)
+{
+       int ret;
+
+       assert(path);
+       assert(rundir);
+
+       /* Build lockfile path from rundir. */
+       ret = snprintf(path, len, "%s/" DEFAULT_LTTNG_SESSIOND_LOCKFILE, rundir);
+       if (ret < 0) {
+               PERROR("snprintf lockfile path");
+       }
+
+       return ret;
+}
+
 /*
  * Cleanup the daemon
  */
@@ -592,14 +614,6 @@ static void cleanup(void)
        DBG("Removing directory %s", path);
        (void) rmdir(path);
 
-       /*
-        * We do NOT rmdir rundir because there are other processes
-        * using it, for instance lttng-relayd, which can start in
-        * parallel with this teardown.
-        */
-
-       free(rundir);
-
        DBG("Cleaning up all sessions");
 
        /* Destroy session list mutex */
@@ -664,6 +678,34 @@ static void cleanup(void)
                free(load_info);
        }
 
+       /*
+        * Cleanup lock file by deleting it and finaly closing it which will
+        * release the file system lock.
+        */
+       if (lockfile_fd >= 0) {
+               char lockfile_path[PATH_MAX];
+
+               ret = generate_lock_file_path(lockfile_path, sizeof(lockfile_path));
+               if (ret > 0) {
+                       ret = remove(lockfile_path);
+                       if (ret < 0) {
+                               PERROR("remove lock file");
+                       }
+                       ret = close(lockfile_fd);
+                       if (ret < 0) {
+                               PERROR("close lock file");
+                       }
+               }
+       }
+
+       /*
+        * We do NOT rmdir rundir because there are other processes
+        * using it, for instance lttng-relayd, which can start in
+        * parallel with this teardown.
+        */
+
+       free(rundir);
+
        /* <fun> */
        DBG("%c[%d;%dm*** assert failed :-) *** ==> %c[%dm%c[%d;%dm"
                        "Matthew, BEET driven development works!%c[%dm",
@@ -957,12 +999,14 @@ static void *thread_manage_kernel(void *data)
                        update_poll_flag = 0;
                }
 
-               DBG("Thread kernel polling on %d fds", LTTNG_POLL_GETNB(&events));
+               DBG("Thread kernel polling");
 
                /* Poll infinite value of time */
        restart:
                health_poll_entry();
                ret = lttng_poll_wait(&events, -1);
+               DBG("Thread kernel return from poll on %d fds",
+                               LTTNG_POLL_GETNB(&events));
                health_poll_exit();
                if (ret < 0) {
                        /*
@@ -988,6 +1032,11 @@ static void *thread_manage_kernel(void *data)
 
                        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) {
@@ -1071,7 +1120,7 @@ static void signal_consumer_condition(struct consumer_data *data, int state)
  */
 static void *thread_manage_consumer(void *data)
 {
-       int sock = -1, i, ret, pollfd, err = -1;
+       int sock = -1, i, ret, pollfd, err = -1, should_quit = 0;
        uint32_t revents, nb_fd;
        enum lttcomm_return_code code;
        struct lttng_poll_event events;
@@ -1133,6 +1182,11 @@ restart:
 
                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) {
@@ -1229,6 +1283,15 @@ restart:
        /* Infinite blocking call, waiting for transmission */
 restart_poll:
        while (1) {
+               health_code_update();
+
+               /* Exit the thread because the thread quit pipe has been triggered. */
+               if (should_quit) {
+                       /* Not a health error. */
+                       err = 0;
+                       goto exit;
+               }
+
                health_poll_entry();
                ret = lttng_poll_wait(&events, -1);
                health_poll_exit();
@@ -1251,13 +1314,18 @@ restart_poll:
 
                        health_code_update();
 
-                       /* Thread quit pipe has been closed. Killing thread. */
-                       ret = sessiond_check_thread_quit_pipe(pollfd, revents);
-                       if (ret) {
-                               err = 0;
-                               goto exit;
+                       if (!revents) {
+                               /* No activity for this FD (poll implementation). */
+                               continue;
                        }
 
+                       /*
+                        * Thread quit pipe has been triggered, flag that we should stop
+                        * but continue the current loop to handle potential data from
+                        * consumer.
+                        */
+                       should_quit = sessiond_check_thread_quit_pipe(pollfd, revents);
+
                        if (pollfd == sock) {
                                /* Event on the consumerd socket */
                                if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
@@ -1285,11 +1353,8 @@ restart_poll:
                                        ERR("Handling metadata request");
                                        goto error;
                                }
-                               break;
-                       } else {
-                               ERR("Unknown pollfd");
-                               goto error;
                        }
+                       /* No need for an else branch all FDs are tested prior. */
                }
                health_code_update();
        }
@@ -1404,12 +1469,14 @@ static void *thread_manage_apps(void *data)
        health_code_update();
 
        while (1) {
-               DBG("Apps thread polling on %d fds", LTTNG_POLL_GETNB(&events));
+               DBG("Apps thread polling");
 
                /* Inifinite blocking call, waiting for transmission */
        restart:
                health_poll_entry();
                ret = lttng_poll_wait(&events, -1);
+               DBG("Apps thread return from poll on %d fds",
+                               LTTNG_POLL_GETNB(&events));
                health_poll_exit();
                if (ret < 0) {
                        /*
@@ -1430,6 +1497,11 @@ static void *thread_manage_apps(void *data)
 
                        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) {
@@ -1608,6 +1680,11 @@ static void sanitize_wait_queue(struct ust_reg_wait_queue *wait_queue)
                uint32_t revents = LTTNG_POLL_GETEV(&events, i);
                int pollfd = LTTNG_POLL_GETFD(&events, i);
 
+               if (!revents) {
+                       /* No activity for this FD (poll implementation). */
+                       continue;
+               }
+
                cds_list_for_each_entry_safe(wait_node, tmp_wait_node,
                                &wait_queue->head, head) {
                        if (pollfd == wait_node->app->sock &&
@@ -1947,6 +2024,11 @@ static void *thread_registration_apps(void *data)
                        revents = LTTNG_POLL_GETEV(&events, i);
                        pollfd = LTTNG_POLL_GETFD(&events, i);
 
+                       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) {
@@ -2974,6 +3056,7 @@ static int process_client_msg(struct command_ctx *cmd_ctx, int sock,
                        }
 
                        /* 32-bit */
+                       pthread_mutex_lock(&ustconsumer32_data.pid_mutex);
                        if (consumerd32_bin[0] != '\0' &&
                                        ustconsumer32_data.pid == 0 &&
                                        cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
@@ -3160,12 +3243,14 @@ skip_domain:
 
                        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;
@@ -3177,6 +3262,7 @@ skip_domain:
                        if (ret <= 0) {
                                DBG("Nothing recv() from client car len data... continuing");
                                *sock_error = 1;
+                               free(filter_expression);
                                free(bytecode);
                                free(exclusion);
                                ret = LTTNG_ERR_FILTER_INVAL;
@@ -3184,6 +3270,7 @@ skip_domain:
                        }
 
                        if ((bytecode->len + sizeof(*bytecode)) != bytecode_len) {
+                               free(filter_expression);
                                free(bytecode);
                                free(exclusion);
                                ret = LTTNG_ERR_FILTER_INVAL;
@@ -3306,31 +3393,12 @@ skip_domain:
                        goto error;
                }
 
-               ret = cmd_set_consumer_uri(cmd_ctx->lsm->domain.type, cmd_ctx->session,
-                               nb_uri, uris);
+               ret = cmd_set_consumer_uri(cmd_ctx->session, nb_uri, uris);
+               free(uris);
                if (ret != LTTNG_OK) {
-                       free(uris);
                        goto error;
                }
 
-               /*
-                * XXX: 0 means that this URI should be applied on the session. Should
-                * be a DOMAIN enuam.
-                */
-               if (cmd_ctx->lsm->domain.type == 0) {
-                       /* Add the URI for the UST session if a consumer is present. */
-                       if (cmd_ctx->session->ust_session &&
-                                       cmd_ctx->session->ust_session->consumer) {
-                               ret = cmd_set_consumer_uri(LTTNG_DOMAIN_UST, cmd_ctx->session,
-                                               nb_uri, uris);
-                       } else if (cmd_ctx->session->kernel_session &&
-                                       cmd_ctx->session->kernel_session->consumer) {
-                               ret = cmd_set_consumer_uri(LTTNG_DOMAIN_KERNEL,
-                                               cmd_ctx->session, nb_uri, uris);
-                       }
-               }
-
-               free(uris);
 
                break;
        }
@@ -3423,7 +3491,7 @@ skip_domain:
        case LTTNG_LIST_CHANNELS:
        {
                int nb_chan;
-               struct lttng_channel *channels;
+               struct lttng_channel *channels = NULL;
 
                nb_chan = cmd_list_channels(cmd_ctx->lsm->domain.type,
                                cmd_ctx->session, &channels);
@@ -3797,6 +3865,11 @@ restart:
                        revents = LTTNG_POLL_GETEV(&events, i);
                        pollfd = LTTNG_POLL_GETFD(&events, i);
 
+                       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) {
@@ -3969,6 +4042,11 @@ static void *thread_manage_clients(void *data)
 
                        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) {
@@ -4163,7 +4241,7 @@ static void usage(void)
        fprintf(stderr, "      --verbose-consumer             Verbose mode for consumer. Activate DBG() macro.\n");
        fprintf(stderr, "      --no-kernel                    Disable kernel tracer\n");
        fprintf(stderr, "      --jul-tcp-port                 JUL application registration TCP port\n");
-       fprintf(stderr, "  -f  --config                       Load daemon configuration file\n");
+       fprintf(stderr, "  -f  --config PATH                  Load daemon configuration file\n");
        fprintf(stderr, "  -l  --load PATH                    Load session configuration\n");
        fprintf(stderr, "      --kmod-probes                  Specify kernel module probes to load\n");
 }
@@ -4178,6 +4256,17 @@ static int set_option(int opt, const char *arg, const char *optname)
 {
        int ret = 0;
 
+       if (arg && arg[0] == '\0') {
+               /*
+                * This only happens if the value is read from daemon config
+                * file. This means the option requires an argument and the
+                * configuration file contains a line such as:
+                * my_option =
+                */
+               ret = -EINVAL;
+               goto end;
+       }
+
        switch (opt) {
        case 0:
                fprintf(stderr, "option %s", optname);
@@ -4198,11 +4287,20 @@ static int set_option(int opt, const char *arg, const char *optname)
                opt_background = 1;
                break;
        case 'g':
+               /*
+                * If the override option is set, the pointer points to a
+                * *non* const thus freeing it even though the variable type is
+                * set to const.
+                */
+               if (tracing_group_name_override) {
+                       free((void *) tracing_group_name);
+               }
                tracing_group_name = strdup(arg);
                if (!tracing_group_name) {
                        perror("strdup");
                        ret = -ENOMEM;
                }
+               tracing_group_name_override = 1;
                break;
        case 'h':
                usage();
@@ -4258,6 +4356,9 @@ static int set_option(int opt, const char *arg, const char *optname)
                }
                break;
        case 'u':
+               if (consumerd32_bin_override) {
+                       free((void *) consumerd32_bin);
+               }
                consumerd32_bin = strdup(arg);
                if (!consumerd32_bin) {
                        perror("strdup");
@@ -4266,6 +4367,9 @@ static int set_option(int opt, const char *arg, const char *optname)
                consumerd32_bin_override = 1;
                break;
        case 'U':
+               if (consumerd32_libdir_override) {
+                       free((void *) consumerd32_libdir);
+               }
                consumerd32_libdir = strdup(arg);
                if (!consumerd32_libdir) {
                        perror("strdup");
@@ -4274,6 +4378,9 @@ static int set_option(int opt, const char *arg, const char *optname)
                consumerd32_libdir_override = 1;
                break;
        case 't':
+               if (consumerd64_bin_override) {
+                       free((void *) consumerd64_bin);
+               }
                consumerd64_bin = strdup(arg);
                if (!consumerd64_bin) {
                        perror("strdup");
@@ -4282,6 +4389,9 @@ static int set_option(int opt, const char *arg, const char *optname)
                consumerd64_bin_override = 1;
                break;
        case 'T':
+               if (consumerd64_libdir_override) {
+                       free((void *) consumerd64_libdir);
+               }
                consumerd64_libdir = strdup(arg);
                if (!consumerd64_libdir) {
                        perror("strdup");
@@ -4290,6 +4400,7 @@ static int set_option(int opt, const char *arg, const char *optname)
                consumerd64_libdir_override = 1;
                break;
        case 'p':
+               free(opt_pidfile);
                opt_pidfile = strdup(arg);
                if (!opt_pidfile) {
                        perror("strdup");
@@ -4315,6 +4426,7 @@ static int set_option(int opt, const char *arg, const char *optname)
                break;
        }
        case 'l':
+               free(opt_load_session_path);
                opt_load_session_path = strdup(arg);
                if (!opt_load_session_path) {
                        perror("strdup");
@@ -4322,6 +4434,7 @@ static int set_option(int opt, const char *arg, const char *optname)
                }
                break;
        case 'P': /* probe modules list */
+               free(kmod_probes_list);
                kmod_probes_list = strdup(arg);
                if (!kmod_probes_list) {
                        perror("strdup");
@@ -4337,6 +4450,23 @@ static int set_option(int opt, const char *arg, const char *optname)
                ret = -1;
        }
 
+end:
+       if (ret == -EINVAL) {
+               const char *opt_name = "unknown";
+               int i;
+
+               for (i = 0; i < sizeof(long_options) / sizeof(struct option);
+                       i++) {
+                       if (opt == long_options[i].val) {
+                               opt_name = long_options[i].name;
+                               break;
+                       }
+               }
+
+               WARN("Invalid argument provided for option \"%s\", using default value.",
+                       opt_name);
+       }
+
        return ret;
 }
 
@@ -4830,6 +4960,24 @@ error:
        return;
 }
 
+/*
+ * Create lockfile using the rundir and return its fd.
+ */
+static int create_lockfile(void)
+{
+       int ret;
+       char lockfile_path[PATH_MAX];
+
+       ret = generate_lock_file_path(lockfile_path, sizeof(lockfile_path));
+       if (ret < 0) {
+               goto error;
+       }
+
+       ret = utils_create_lock_file(lockfile_path);
+error:
+       return ret;
+}
+
 /*
  * Write JUL TCP port using the rundir.
  */
@@ -4949,6 +5097,10 @@ int main(int argc, char **argv)
 
        if (is_root) {
                rundir = strdup(DEFAULT_LTTNG_RUNDIR);
+               if (!rundir) {
+                       ret = -ENOMEM;
+                       goto error;
+               }
 
                /* Create global run dir with root access */
                ret = create_lttng_rundir(rundir);
@@ -5035,6 +5187,11 @@ int main(int argc, char **argv)
                }
        }
 
+       lockfile_fd = create_lockfile();
+       if (lockfile_fd < 0) {
+               goto error;
+       }
+
        /* Set consumer initial state */
        kernel_consumerd_state = CONSUMER_STOPPED;
        ust_consumerd_state = CONSUMER_STOPPED;
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