X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=libringbuffer%2Ffrontend_internal.h;h=1a9c2d4b78e82e7645e1267430b41e6f0c3218c2;hb=730be651d21f3950980fd61e1c65953017c6322e;hp=4ad921ec0ec8263086cddbf1c11044110dc672f6;hpb=1e1782558131e5669466639d7f28e2f08b0d026d;p=lttng-ust.git

diff --git a/libringbuffer/frontend_internal.h b/libringbuffer/frontend_internal.h
index 4ad921ec..1a9c2d4b 100644
--- a/libringbuffer/frontend_internal.h
+++ b/libringbuffer/frontend_internal.h
@@ -260,14 +260,11 @@ 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
@@ -279,6 +276,9 @@ 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));