Fix: truncate the metadata file in shm-path
[lttng-tools.git] / src / bin / lttng-sessiond / cmd.c
index 1327e42e4ddfa8efdd5a550179000a8f77f34150..cc81906b6267ffc104ee357741d0b099af9fbc3c 100644 (file)
@@ -277,7 +277,10 @@ static void list_lttng_channels(enum lttng_domain_type domain,
                                &iter.iter, uchan, node.node) {
                        uint64_t discarded_events = 0, lost_packets = 0;
 
-                       strncpy(channels[i].name, uchan->name, LTTNG_SYMBOL_NAME_LEN);
+                       if (lttng_strncpy(channels[i].name, uchan->name,
+                                       LTTNG_SYMBOL_NAME_LEN)) {
+                               break;
+                       }
                        channels[i].attr.overwrite = uchan->attr.overwrite;
                        channels[i].attr.subbuf_size = uchan->attr.subbuf_size;
                        channels[i].attr.num_subbuf = uchan->attr.num_subbuf;
@@ -1330,16 +1333,6 @@ int cmd_enable_channel(struct ltt_session *session,
                attr->attr.switch_timer_interval = 0;
        }
 
-       /*
-        * The ringbuffer (both in user space and kernel) behave badly in overwrite
-        * mode and with less than 2 subbuf so block it right away and send back an
-        * invalid attribute error.
-        */
-       if (attr->attr.overwrite && attr->attr.num_subbuf < 2) {
-               ret = LTTNG_ERR_INVALID;
-               goto error;
-       }
-
        switch (domain->type) {
        case LTTNG_DOMAIN_KERNEL:
        {
@@ -2444,7 +2437,15 @@ int cmd_stop_trace(struct ltt_session *session)
        if (ksession && ksession->active) {
                DBG("Stop kernel tracing");
 
-               /* Flush metadata if exist */
+               ret = kernel_stop_session(ksession);
+               if (ret < 0) {
+                       ret = LTTNG_ERR_KERN_STOP_FAIL;
+                       goto error;
+               }
+
+               kernel_wait_quiescent(kernel_tracer_fd);
+
+               /* Flush metadata after stopping (if exists) */
                if (ksession->metadata_stream_fd >= 0) {
                        ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
                        if (ret < 0) {
@@ -2452,7 +2453,7 @@ int cmd_stop_trace(struct ltt_session *session)
                        }
                }
 
-               /* Flush all buffers before stopping */
+               /* Flush all buffers after stopping */
                cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
                        ret = kernel_flush_buffer(kchan);
                        if (ret < 0) {
@@ -2460,14 +2461,6 @@ int cmd_stop_trace(struct ltt_session *session)
                        }
                }
 
-               ret = kernel_stop_session(ksession);
-               if (ret < 0) {
-                       ret = LTTNG_ERR_KERN_STOP_FAIL;
-                       goto error;
-               }
-
-               kernel_wait_quiescent(kernel_tracer_fd);
-
                ksession->active = 0;
        }
 
@@ -2755,64 +2748,6 @@ int cmd_destroy_session(struct ltt_session *session, int wpipe)
        return ret;
 }
 
-/*
- * Command LTTNG_CALIBRATE processed by the client thread.
- */
-int cmd_calibrate(enum lttng_domain_type domain,
-               struct lttng_calibrate *calibrate)
-{
-       int ret;
-
-       switch (domain) {
-       case LTTNG_DOMAIN_KERNEL:
-       {
-               struct lttng_kernel_calibrate kcalibrate;
-
-               switch (calibrate->type) {
-               case LTTNG_CALIBRATE_FUNCTION:
-               default:
-                       /* Default and only possible calibrate option. */
-                       kcalibrate.type = LTTNG_KERNEL_CALIBRATE_KRETPROBE;
-                       break;
-               }
-
-               ret = kernel_calibrate(kernel_tracer_fd, &kcalibrate);
-               if (ret < 0) {
-                       ret = LTTNG_ERR_KERN_ENABLE_FAIL;
-                       goto error;
-               }
-               break;
-       }
-       case LTTNG_DOMAIN_UST:
-       {
-               struct lttng_ust_calibrate ucalibrate;
-
-               switch (calibrate->type) {
-               case LTTNG_CALIBRATE_FUNCTION:
-               default:
-                       /* Default and only possible calibrate option. */
-                       ucalibrate.type = LTTNG_UST_CALIBRATE_TRACEPOINT;
-                       break;
-               }
-
-               ret = ust_app_calibrate_glb(&ucalibrate);
-               if (ret < 0) {
-                       ret = LTTNG_ERR_UST_CALIBRATE_FAIL;
-                       goto error;
-               }
-               break;
-       }
-       default:
-               ret = LTTNG_ERR_UND;
-               goto error;
-       }
-
-       ret = LTTNG_OK;
-
-error:
-       return ret;
-}
-
 /*
  * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
  */
@@ -3214,11 +3149,10 @@ int cmd_snapshot_add_output(struct ltt_session *session,
        DBG("Cmd snapshot add output for session %s", session->name);
 
        /*
-        * Permission denied to create an output if the session is not
-        * set in no output mode.
+        * Can't create an output if the session is not set in no-output mode.
         */
        if (session->output_traces) {
-               ret = LTTNG_ERR_EPERM;
+               ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
                goto error;
        }
 
@@ -3282,7 +3216,7 @@ int cmd_snapshot_del_output(struct ltt_session *session,
         * set in no output mode.
         */
        if (session->output_traces) {
-               ret = LTTNG_ERR_EPERM;
+               ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
                goto error;
        }
 
@@ -3334,19 +3268,19 @@ ssize_t cmd_snapshot_list_outputs(struct ltt_session *session,
         * set in no output mode.
         */
        if (session->output_traces) {
-               ret = -LTTNG_ERR_EPERM;
-               goto error;
+               ret = -LTTNG_ERR_NOT_SNAPSHOT_SESSION;
+               goto end;
        }
 
        if (session->snapshot.nb_output == 0) {
                ret = 0;
-               goto error;
+               goto end;
        }
 
        list = zmalloc(session->snapshot.nb_output * sizeof(*list));
        if (!list) {
                ret = -LTTNG_ERR_NOMEM;
-               goto error;
+               goto end;
        }
 
        /* Copy list from session to the new list object. */
@@ -3356,10 +3290,18 @@ ssize_t cmd_snapshot_list_outputs(struct ltt_session *session,
                assert(output->consumer);
                list[idx].id = output->id;
                list[idx].max_size = output->max_size;
-               strncpy(list[idx].name, output->name, sizeof(list[idx].name));
+               if (lttng_strncpy(list[idx].name, output->name,
+                               sizeof(list[idx].name))) {
+                       ret = -LTTNG_ERR_INVALID;
+                       goto error;
+               }
                if (output->consumer->type == CONSUMER_DST_LOCAL) {
-                       strncpy(list[idx].ctrl_url, output->consumer->dst.trace_path,
-                                       sizeof(list[idx].ctrl_url));
+                       if (lttng_strncpy(list[idx].ctrl_url,
+                                       output->consumer->dst.trace_path,
+                                       sizeof(list[idx].ctrl_url))) {
+                               ret = -LTTNG_ERR_INVALID;
+                               goto error;
+                       }
                } else {
                        /* Control URI. */
                        ret = uri_to_str_url(&output->consumer->dst.net.control,
@@ -3384,8 +3326,9 @@ ssize_t cmd_snapshot_list_outputs(struct ltt_session *session,
        list = NULL;
        ret = session->snapshot.nb_output;
 error:
-       free(list);
        rcu_read_unlock();
+       free(list);
+end:
        return ret;
 }
 
@@ -3396,7 +3339,7 @@ error:
  * Return 0 if the metadata can be generated, a LTTNG_ERR code otherwise.
  */
 static
-int check_metadata_regenerate_support(struct ltt_session *session)
+int check_regenerate_metadata_support(struct ltt_session *session)
 {
        int ret;
 
@@ -3435,7 +3378,28 @@ end:
 }
 
 static
-int ust_metadata_regenerate(struct ltt_ust_session *usess)
+int clear_metadata_file(int fd)
+{
+       int ret;
+
+       ret = lseek(fd, 0, SEEK_SET);
+       if (ret < 0) {
+               PERROR("lseek");
+               goto end;
+       }
+
+       ret = ftruncate(fd, 0);
+       if (ret < 0) {
+               PERROR("ftruncate");
+               goto end;
+       }
+
+end:
+       return ret;
+}
+
+static
+int ust_regenerate_metadata(struct ltt_ust_session *usess)
 {
        int ret = 0;
        struct buffer_reg_uid *uid_reg = NULL;
@@ -3455,6 +3419,15 @@ int ust_metadata_regenerate(struct ltt_ust_session *usess)
                memset(registry->metadata, 0, registry->metadata_alloc_len);
                registry->metadata_len = 0;
                registry->metadata_version++;
+               if (registry->metadata_fd > 0) {
+                       /* Clear the metadata file's content. */
+                       ret = clear_metadata_file(registry->metadata_fd);
+                       if (ret) {
+                               pthread_mutex_unlock(&registry->lock);
+                               goto end;
+                       }
+               }
+
                ret = ust_metadata_session_statedump(registry, NULL,
                                registry->major, registry->minor);
                if (ret) {
@@ -3496,7 +3469,7 @@ end:
 }
 
 /*
- * Command LTTNG_METADATA_REGENERATE from the lttng-ctl library.
+ * Command LTTNG_REGENERATE_METADATA from the lttng-ctl library.
  *
  * Ask the consumer to truncate the existing metadata file(s) and
  * then regenerate the metadata. Live and per-pid sessions are not
@@ -3504,19 +3477,19 @@ end:
  *
  * Return 0 on success or else a LTTNG_ERR code.
  */
-int cmd_metadata_regenerate(struct ltt_session *session)
+int cmd_regenerate_metadata(struct ltt_session *session)
 {
        int ret;
 
        assert(session);
 
-       ret = check_metadata_regenerate_support(session);
+       ret = check_regenerate_metadata_support(session);
        if (ret) {
                goto end;
        }
 
        if (session->kernel_session) {
-               ret = kernctl_session_metadata_regenerate(
+               ret = kernctl_session_regenerate_metadata(
                                session->kernel_session->fd);
                if (ret < 0) {
                        ERR("Failed to regenerate the kernel metadata");
@@ -3525,7 +3498,7 @@ int cmd_metadata_regenerate(struct ltt_session *session)
        }
 
        if (session->ust_session) {
-               ret = ust_metadata_regenerate(session->ust_session);
+               ret = ust_regenerate_metadata(session->ust_session);
                if (ret < 0) {
                        ERR("Failed to regenerate the UST metadata");
                        goto end;
@@ -3538,6 +3511,60 @@ end:
        return ret;
 }
 
+/*
+ * Command LTTNG_REGENERATE_STATEDUMP from the lttng-ctl library.
+ *
+ * Ask the tracer to regenerate a new statedump.
+ *
+ * Return 0 on success or else a LTTNG_ERR code.
+ */
+int cmd_regenerate_statedump(struct ltt_session *session)
+{
+       int ret;
+
+       assert(session);
+
+       if (!session->active) {
+               ret = LTTNG_ERR_SESSION_NOT_STARTED;
+               goto end;
+       }
+       ret = 0;
+
+       if (session->kernel_session) {
+               ret = kernctl_session_regenerate_statedump(
+                               session->kernel_session->fd);
+               /*
+                * Currently, the statedump in kernel can only fail if out
+                * of memory.
+                */
+               if (ret < 0) {
+                       if (ret == -ENOMEM) {
+                               ret = LTTNG_ERR_REGEN_STATEDUMP_NOMEM;
+                       } else {
+                               ret = LTTNG_ERR_REGEN_STATEDUMP_FAIL;
+                       }
+                       ERR("Failed to regenerate the kernel statedump");
+                       goto end;
+               }
+       }
+
+       if (session->ust_session) {
+               ret = ust_app_regenerate_statedump_all(session->ust_session);
+               /*
+                * Currently, the statedump in UST always returns 0.
+                */
+               if (ret < 0) {
+                       ret = LTTNG_ERR_REGEN_STATEDUMP_FAIL;
+                       ERR("Failed to regenerate the UST statedump");
+                       goto end;
+               }
+       }
+       DBG("Cmd regenerate statedump for session %s", session->name);
+       ret = LTTNG_OK;
+
+end:
+       return ret;
+}
 
 /*
  * Send relayd sockets from snapshot output to consumer. Ignore request if the
@@ -3805,7 +3832,7 @@ int cmd_snapshot_record(struct ltt_session *session,
         * set in no output mode.
         */
        if (session->output_traces) {
-               ret = LTTNG_ERR_EPERM;
+               ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
                goto error;
        }
 
@@ -3895,8 +3922,12 @@ int cmd_snapshot_record(struct ltt_session *session,
 
                        /* Use temporary name. */
                        if (*output->name != '\0') {
-                               strncpy(tmp_output.name, output->name,
-                                               sizeof(tmp_output.name));
+                               if (lttng_strncpy(tmp_output.name, output->name,
+                                               sizeof(tmp_output.name))) {
+                                       ret = LTTNG_ERR_INVALID;
+                                       rcu_read_unlock();
+                                       goto error;
+                               }
                        }
 
                        tmp_output.nb_snapshot = session->snapshot.nb_snapshot;
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