X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;ds=sidebyside;f=libringbuffer%2Ffrontend_internal.h;h=72dfe2813336cabc16dca7f162824cce70837839;hb=f5630de5c8309827e11720b797bcb09a1855fe97;hp=68aa70223ea5529acd3ecdf67a3c9b4057fcdb49;hpb=b404c548cecfa0f5f2f29195f1217ada5889648a;p=lttng-ust.git

diff --git a/libringbuffer/frontend_internal.h b/libringbuffer/frontend_internal.h
index 68aa7022..72dfe281 100644
--- a/libringbuffer/frontend_internal.h
+++ b/libringbuffer/frontend_internal.h
@@ -233,14 +233,11 @@ 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);
+	struct commit_counters_hot *cc_hot;
 
 	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
@@ -252,6 +249,9 @@ 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);
+		cc_hot = shmp_index(handle, buf->commit_hot, idx);
+		if (caa_unlikely(!cc_hot))
+			return 0;
 		commit_count = v_read(config, &cc_hot->cc);
 	} while (offset != v_read(config, &buf->offset));