sessiond: lttng: Add command to check kernel tracer status

[lttng-tools.git] / src / bin / lttng / commands / enable_channels.cpp

diff --git a/src/bin/lttng/commands/enable_channels.cpp b/src/bin/lttng/commands/enable_channels.cpp
index c302132fbca258e4e5234c679ef4073a38612092..1638d0d446b88108aa2d96e595f622a2831e6298 100644 (file)
--- a/src/bin/lttng/commands/enable_channels.cpp
+++ b/src/bin/lttng/commands/enable_channels.cpp
@@ -11,6 +11,7 @@
 
 #include <common/mi-lttng.hpp>
 #include <common/sessiond-comm/sessiond-comm.hpp>
+#include <common/lttng-kernel.hpp>
 #include <common/utils.hpp>
 
 #include <lttng/domain-internal.hpp>
@@ -141,6 +142,7 @@ static int enable_channel(char *session_name, char *channel_list)
 {
        struct lttng_channel *channel = nullptr;
        int ret = CMD_SUCCESS, warn = 0, error = 0, success = 0;
+       enum lttng_kernel_tracer_status kernel_tracer_status;
        char *channel_name;
        struct lttng_domain dom;
 
@@ -309,6 +311,43 @@ static int enable_channel(char *session_name, char *channel_list)
                                error = 1;
                                break;
                        }
+                       /*
+                        * Ask the sessiond for the more details on the status of the kernel tracer.
+                        */
+                       ret = lttng_get_kernel_tracer_status(&kernel_tracer_status);
+                       if (ret < 0) {
+                               ERR("Failed to get kernel tracer status: %s", lttng_strerror(ret));
+                       } else {
+                               switch (kernel_tracer_status) {
+                               case LTTNG_KERNEL_TRACER_STATUS_INITIALIZED:
+                                       break;
+                               case LTTNG_KERNEL_TRACER_STATUS_ERR_MODULES_UNKNOWN:
+                                       MSG("\tKernel module loading failed");
+                                       break;
+                               case LTTNG_KERNEL_TRACER_STATUS_ERR_MODULES_MISSING:
+                                       MSG("\tMissing one or more required kernel modules");
+                                       break;
+                               case LTTNG_KERNEL_TRACER_STATUS_ERR_MODULES_SIGNATURE:
+                                       MSG("\tKernel module signature error prevented loading of one or more required kernel modules");
+                                       break;
+                               case LTTNG_KERNEL_TRACER_STATUS_ERR_NEED_ROOT:
+                                       MSG("\tlttng-sessiond isn't running as root");
+                                       break;
+                               case LTTNG_KERNEL_TRACER_STATUS_ERR_NOTIFIER:
+                                       MSG("\tFailed to setup notifiers");
+                                       break;
+                               case LTTNG_KERNEL_TRACER_STATUS_ERR_OPEN_PROC_LTTNG:
+                                       MSG("\tlttng-sessiond failed to open proc lttng");
+                                       break;
+                               case LTTNG_KERNEL_TRACER_STATUS_ERR_VERSION_MISMATCH:
+                                       MSG("\tVersion mismatch between kernel tracer and kernel tracer ABI");
+                                       break;
+                               default:
+                                       MSG("\tUnknown kernel tracer status (%d)", kernel_tracer_status);
+                                       break;
+                               }
+                               MSG("\tConsult lttng-sessiond logs for more information");
+                       }
                } else {
                        MSG("%s channel %s enabled for session %s",
                            lttng_domain_type_str(dom.type),