[PATCH v2 3/3] ring-buffer: Allow sparse CPU masks in ring_buffer_desc()

[Vincent Donnefort]

No user currently relies on sparse CPU masks, but the descriptor logic already
supports them via linear fallback. Remove the arbitrary limitation.

Fixes: 2e67fabd8b77 ("ring-buffer: Introduce ring-buffer remotes")
Reported-by: Sashiko <sashiko-bot@xxxxxxxxxx>
Signed-off-by: Vincent Donnefort <vdonnefort@xxxxxxxxxx>

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 56a328e94395..4e7b4ce7b8a7 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -2329,10 +2329,7 @@ static struct ring_buffer_desc *ring_buffer_desc(struct trace_buffer_desc *trace
 	size_t len;
 	int i;
 
-	if (!trace_desc)
-		return NULL;
-
-	if (cpu >= trace_desc->nr_cpus)
+	if (!trace_desc || !trace_desc->nr_cpus)
 		return NULL;
 
 	end = (struct ring_buffer_desc *)((void *)trace_desc + trace_desc->struct_len);
-- 
2.55.0.795.g602f6c329a-goog