Fix: possible null dereference

[lttng-tools.git] / src / bin / lttng-sessiond / cmd.c

diff --git a/src/bin/lttng-sessiond/cmd.c b/src/bin/lttng-sessiond/cmd.c
index b668b56d48f90559ff3b63bc61723993dc8c23a7..5e522d6fe0886108b87df756e930a6519a5a8a09 100644 (file)
--- a/src/bin/lttng-sessiond/cmd.c
+++ b/src/bin/lttng-sessiond/cmd.c
@@ -1,19 +1,9 @@
 /*
- * Copyright (C) 2012 - David Goulet <dgoulet@efficios.com>
- * Copyright (C) 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ * Copyright (C) 2012 David Goulet <dgoulet@efficios.com>
+ * Copyright (C) 2016 Jérémie Galarneau <jeremie.galarneau@efficios.com>
  *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License, version 2 only, as
- * published by the Free Software Foundation.
+ * SPDX-License-Identifier: GPL-2.0-only
  *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along with
- * this program; if not, write to the Free Software Foundation, Inc., 51
- * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
 #define _LGPL_SOURCE
@@ -2581,13 +2571,12 @@ ssize_t cmd_list_syscalls(struct lttng_event **events)
  *
  * Called with session lock held.
  */
-ssize_t cmd_list_tracker_ids(enum lttng_tracker_type tracker_type,
+int cmd_list_tracker_ids(enum lttng_tracker_type tracker_type,
                struct ltt_session *session,
                enum lttng_domain_type domain,
-               struct lttng_tracker_id ***ids)
+               struct lttng_tracker_ids **ids)
 {
-       int ret;
-       ssize_t nr_pids = 0;
+       int ret = LTTNG_OK;
 
        switch (domain) {
        case LTTNG_DOMAIN_KERNEL:
@@ -2595,9 +2584,9 @@ ssize_t cmd_list_tracker_ids(enum lttng_tracker_type tracker_type,
                struct ltt_kernel_session *ksess;
 
                ksess = session->kernel_session;
-               nr_pids = kernel_list_tracker_ids(tracker_type, ksess, ids);
-               if (nr_pids < 0) {
-                       ret = LTTNG_ERR_KERN_LIST_FAIL;
+               ret = kernel_list_tracker_ids(tracker_type, ksess, ids);
+               if (ret != LTTNG_OK) {
+                       ret = -LTTNG_ERR_KERN_LIST_FAIL;
                        goto error;
                }
                break;
@@ -2607,9 +2596,9 @@ ssize_t cmd_list_tracker_ids(enum lttng_tracker_type tracker_type,
                struct ltt_ust_session *usess;
 
                usess = session->ust_session;
-               nr_pids = trace_ust_list_tracker_ids(tracker_type, usess, ids);
-               if (nr_pids < 0) {
-                       ret = LTTNG_ERR_UST_LIST_FAIL;
+               ret = trace_ust_list_tracker_ids(tracker_type, usess, ids);
+               if (ret != LTTNG_OK) {
+                       ret = -LTTNG_ERR_UST_LIST_FAIL;
                        goto error;
                }
                break;
@@ -2618,15 +2607,13 @@ ssize_t cmd_list_tracker_ids(enum lttng_tracker_type tracker_type,
        case LTTNG_DOMAIN_JUL:
        case LTTNG_DOMAIN_PYTHON:
        default:
-               ret = LTTNG_ERR_UND;
+               ret = -LTTNG_ERR_UND;
                goto error;
        }
 
-       return nr_pids;
-
 error:
        /* Return negative value to differentiate return code */
-       return -ret;
+       return ret;
 }
 
 /*
@@ -2654,7 +2641,8 @@ int cmd_start_trace(struct ltt_session *session)
        /* Is the session already started? */
        if (session->active) {
                ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
-               goto error;
+               /* Perform nothing */
+               goto end;
        }
 
        if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING &&
@@ -2782,6 +2770,7 @@ error:
                session->cleared_after_last_stop =
                                session_cleared_after_last_stop;
        }
+end:
        return ret;
 }
 
@@ -4585,7 +4574,7 @@ int64_t get_session_nb_packets_per_stream(const struct ltt_session *session,
                }
                cur_nb_packets++;
        }
-       if (!cur_nb_packets) {
+       if (!cur_nb_packets && size_left != max_size) {
                /* Not enough room to grab one packet of each stream, error. */
                return -1;
        }
@@ -4698,7 +4687,7 @@ enum lttng_error_code snapshot_record(struct ltt_session *session,
                        snapshot_output->max_size);
        if (nb_packets_per_stream < 0) {
                ret_code = LTTNG_ERR_MAX_SIZE_INVALID;
-               goto error;
+               goto error_close_trace_chunk;
        }
 
        if (session->kernel_session) {
@@ -4706,7 +4695,7 @@ enum lttng_error_code snapshot_record(struct ltt_session *session,
                                snapshot_kernel_consumer_output, session,
                                wait, nb_packets_per_stream);
                if (ret_code != LTTNG_OK) {
-                       goto error;
+                       goto error_close_trace_chunk;
                }
        }
 
@@ -4715,10 +4704,11 @@ enum lttng_error_code snapshot_record(struct ltt_session *session,
                                snapshot_ust_consumer_output, session,
                                wait, nb_packets_per_stream);
                if (ret_code != LTTNG_OK) {
-                       goto error;
+                       goto error_close_trace_chunk;
                }
        }
 
+error_close_trace_chunk:
        if (session_set_trace_chunk(session, NULL, &snapshot_trace_chunk)) {
                ERR("Failed to release the current trace chunk of session \"%s\"",
                                session->name);