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 da2c59d8f486c11c6e3db8759c15e78805a666f0..79d6012bb1f19a4a6b0835546a82d2cf9ac7e991 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);