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Commit 98277991 authored by Steven Rostedt's avatar Steven Rostedt Committed by Steven Rostedt
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ring-buffer: do not swap buffers during a commit 



If a commit is taking place on a CPU ring buffer, do not allow it to
be swapped. Return -EBUSY when this is detected instead.

Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 41b6a95d

kernel/trace/ring_buffer.c

+9 −2
Original line number Diff line number Diff line
@@ -3519,16 +3519,23 @@ int ring_buffer_swap_cpu(struct ring_buffer *buffer_a, 
	atomic_inc(&cpu_buffer_a->record_disabled);

	atomic_inc(&cpu_buffer_b->record_disabled);



	ret = -EBUSY;

	if (local_read(&cpu_buffer_a->committing))

		goto out_dec;

	if (local_read(&cpu_buffer_b->committing))

		goto out_dec;



	buffer_a->buffers[cpu] = cpu_buffer_b;

	buffer_b->buffers[cpu] = cpu_buffer_a;



	cpu_buffer_b->buffer = buffer_a;

	cpu_buffer_a->buffer = buffer_b;



	ret = 0;



out_dec:

	atomic_dec(&cpu_buffer_a->record_disabled);

	atomic_dec(&cpu_buffer_b->record_disabled);



	ret = 0;

out:

	return ret;

}