From 6b450d2533e2c1c71fbe7f1bdce0bb1c9f813030 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Tue, 14 Jan 2014 08:43:01 -0500 Subject: [PATCH] tracing: Disable tracers before deletion of instance When an instance is about to be deleted, make sure the tracer is set to nop. If it isn't reset the tracer and set it to the nop tracer, otherwise memory leaks and bad pointers may result. Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index da9543cdbe7a..7d5913bb46e8 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3907,6 +3907,23 @@ create_trace_option_files(struct trace_array *tr, struct tracer *tracer); static void destroy_trace_option_files(struct trace_option_dentry *topts); +/* + * Used to clear out the tracer before deletion of an instance. + * Must have trace_types_lock held. + */ +static void tracing_set_nop(struct trace_array *tr) +{ + if (tr->current_trace == &nop_trace) + return; + + tr->current_trace->enabled = false; + + if (tr->current_trace->reset) + tr->current_trace->reset(tr); + + tr->current_trace = &nop_trace; +} + static int tracing_set_tracer(struct trace_array *tr, const char *buf) { static struct trace_option_dentry *topts; @@ -6142,6 +6159,7 @@ static int instance_delete(const char *name) list_del(&tr->list); + tracing_set_nop(tr); event_trace_del_tracer(tr); debugfs_remove_recursive(tr->dir); free_percpu(tr->trace_buffer.data);