port fix from lttng kernel tracer 0.92

diff --git a/libust/buffers.c b/libust/buffers.c
index b7b2318cb748c47acf924ace7c6aacde4f2b1652..c2928c03092fa77417d33e8368ebd5306f56a36d 100644 (file)
--- a/libust/buffers.c
+++ b/libust/buffers.c
@@ -482,6 +482,13 @@ static void ltt_relay_print_errors(struct ltt_trace_struct *trace,
        struct ust_buffer *ltt_buf = channel->buf;
        long cons_off;
 
+       /*
+        * Can be called in the error path of allocation when
+        * trans_channel_data is not yet set.
+        */
+       if (!channel)
+               return;
+
        for (cons_off = atomic_long_read(&ltt_buf->consumed);
                        (SUBBUF_TRUNC(local_read(&ltt_buf->offset),
                                      channel)