X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=libringbuffer%2Ffrontend_internal.h;h=68aa70223ea5529acd3ecdf67a3c9b4057fcdb49;hb=15500a1bb134d6bbd409da5568308c2a41291928;hp=10d6c4db789bbf498e3188a1a339c5e94223653f;hpb=3d3c3833d4d119acde0a3fdb2c472aea010cd7e7;p=lttng-ust.git

diff --git a/libringbuffer/frontend_internal.h b/libringbuffer/frontend_internal.h
index 10d6c4db..68aa7022 100644
--- a/libringbuffer/frontend_internal.h
+++ b/libringbuffer/frontend_internal.h
@@ -233,10 +233,14 @@ int lib_ring_buffer_reserve_committed(const struct lttng_ust_lib_ring_buffer_con
 				      struct lttng_ust_shm_handle *handle)
 {
 	unsigned long offset, idx, commit_count;
+	struct commit_counters_hot *cc_hot = shmp_index(handle, buf->commit_hot, idx);
 
 	CHAN_WARN_ON(chan, config->alloc != RING_BUFFER_ALLOC_PER_CPU);
 	CHAN_WARN_ON(chan, config->sync != RING_BUFFER_SYNC_PER_CPU);
 
+	if (caa_unlikely(!cc_hot))
+		return 0;
+
 	/*
 	 * Read offset and commit count in a loop so they are both read
 	 * atomically wrt interrupts. By deal with interrupt concurrency by
@@ -248,7 +252,7 @@ int lib_ring_buffer_reserve_committed(const struct lttng_ust_lib_ring_buffer_con
 	do {
 		offset = v_read(config, &buf->offset);
 		idx = subbuf_index(offset, chan);
-		commit_count = v_read(config, &shmp_index(handle, buf->commit_hot, idx)->cc);
+		commit_count = v_read(config, &cc_hot->cc);
 	} while (offset != v_read(config, &buf->offset));
 
 	return ((buf_trunc(offset, chan) >> chan->backend.num_subbuf_order)