Fix OOPS caused by reference of config pointer

[lttng-modules.git] / lib / ringbuffer / backend_types.h

diff --git a/lib/ringbuffer/backend_types.h b/lib/ringbuffer/backend_types.h
index 3d1fcc064a332973ce64449596866027bbfc6008..4578185c3c75d8a1fb307a5e78ddbb1567bbd878 100644 (file)
--- a/lib/ringbuffer/backend_types.h
+++ b/lib/ringbuffer/backend_types.h
@@ -72,7 +72,12 @@ struct channel_backend {
        u64 start_tsc;                  /* Channel creation TSC value */
        void *priv;                     /* Client-specific information */
        struct notifier_block cpu_hp_notifier;   /* CPU hotplug notifier */
-       const struct lib_ring_buffer_config *config; /* Ring buffer configuration */
+       /*
+        * We need to copy config because the module containing the
+        * source config can vanish before the last reference to this
+        * channel's streams is released.
+        */
+       struct lib_ring_buffer_config config; /* Ring buffer configuration */
        cpumask_var_t cpumask;          /* Allocated per-cpu buffers cpumask */
        char name[NAME_MAX];            /* Channel name */
 };