From: "Steven Rostedt (Red Hat)" The ring_buffer_write() function isn't protected by the trace recursive writes. Luckily, this function is not used as much and is unlikely to ever recurse. But it should still have the protection, because even a call to ring_buffer_lock_reserve() could cause ring buffer corruption if called when ring_buffer_write() is being used. Signed-off-by: Steven Rostedt --- kernel/trace/ring_buffer.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 1c037ad923db..6d6ebcea3463 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -3013,9 +3013,12 @@ int ring_buffer_write(struct ring_buffer *buffer, if (length > BUF_MAX_DATA_SIZE) goto out; + if (unlikely(trace_recursive_lock(cpu_buffer))) + goto out; + event = rb_reserve_next_event(buffer, cpu_buffer, length); if (!event) - goto out; + goto out_unlock; body = rb_event_data(event); @@ -3026,6 +3029,10 @@ int ring_buffer_write(struct ring_buffer *buffer, rb_wakeups(buffer, cpu_buffer); ret = 0; + + out_unlock: + trace_recursive_unlock(cpu_buffer); + out: preempt_enable_notrace(); -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/