ring-buffer: Prevent resizing of persistent ring buffer

Dynamically resizing a persistent ring buffer is not possible. Disable
the feature.

Cc: stable@vger.kernel.org
Fixes: be68d63a139b ("ring-buffer: Add ring_buffer_alloc_range()")
Link: https://patch.msgid.link/20260806211306.3704194-2-vdonnefort@google.com
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 58dc899..09d502e 100644 (file)
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -2528,6 +2528,8 @@ rb_allocate_cpu_buffer(struct trace_buffer *buffer, long nr_pages, int cpu)
                if (cpu_buffer->ring_meta->head_buffer)
                        rb_meta_buffer_update(cpu_buffer, bpage);
                bpage->range = 1;
+
+               atomic_inc(&cpu_buffer->resize_disabled);
        } else if (buffer->remote) {
                struct ring_buffer_desc *desc = ring_buffer_desc(buffer->remote->desc, cpu);