ring-buffer: do not reset while in a commit

The callers of reset must ensure that no commit can be taking place
at the time of the reset. If it does then we may corrupt the ring buffer.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index da2c59d..79d6012 100644 (file)
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -3373,12 +3373,16 @@ void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu)
 
        spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
 
+       if (RB_WARN_ON(cpu_buffer, local_read(&cpu_buffer->committing)))
+               goto out;
+
        __raw_spin_lock(&cpu_buffer->lock);
 
        rb_reset_cpu(cpu_buffer);
 
        __raw_spin_unlock(&cpu_buffer->lock);
 
+ out:
        spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
 
        atomic_dec(&cpu_buffer->record_disabled);