[072/150] tracing: Keep overwrite in sync between regular and snapshot buffers

Submitted by Luis Henriques on March 26, 2013, 3:19 p.m.

Details

Message ID 1364311249-14454-73-git-send-email-luis.henriques@canonical.com
State New
Headers show

Commit Message

Luis Henriques March 26, 2013, 3:19 p.m.
3.5.7.9 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: "Steven Rostedt (Red Hat)" <rostedt@goodmis.org>

commit 80902822658aab18330569587cdb69ac1dfdcea8 upstream.

Changing the overwrite mode for the ring buffer via the trace
option only sets the normal buffer. But the snapshot buffer could
swap with it, and then the snapshot would be in non overwrite mode
and the normal buffer would be in overwrite mode, even though the
option flag states otherwise.

Keep the two buffers overwrite modes in sync.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
[ luis: adjust context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
 kernel/trace/trace.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

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diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index bd1df78..199f77b 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2776,8 +2776,12 @@  static void set_tracer_flags(unsigned int mask, int enabled)
 	if (mask == TRACE_ITER_RECORD_CMD)
 		trace_event_enable_cmd_record(enabled);
 
-	if (mask == TRACE_ITER_OVERWRITE)
+	if (mask == TRACE_ITER_OVERWRITE) {
 		ring_buffer_change_overwrite(global_trace.buffer, enabled);
+#ifdef CONFIG_TRACER_MAX_TRACE
+		ring_buffer_change_overwrite(max_tr.buffer, enabled);
+#endif
+	}
 }
 
 static ssize_t