function-graph: prevent more than one tracer registering
Impact: prevent crash due to multiple function graph tracers The function graph tracer can currently only handle a single tracer being registered. If another tracer registers with the function graph tracer it can crash the system. Signed-off-by: Steven Rostedt <srostedt@redhat.com>
This commit is contained in:
parent
5d1a03dc54
commit
05ce5818ad
1 changed files with 6 additions and 0 deletions
|
@ -2643,6 +2643,12 @@ int register_ftrace_graph(trace_func_graph_ret_t retfunc,
|
|||
|
||||
mutex_lock(&ftrace_lock);
|
||||
|
||||
/* we currently allow only one tracer registered at a time */
|
||||
if (atomic_read(&ftrace_graph_active)) {
|
||||
ret = -EBUSY;
|
||||
goto out;
|
||||
}
|
||||
|
||||
ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call;
|
||||
register_pm_notifier(&ftrace_suspend_notifier);
|
||||
|
||||
|
|
Reference in a new issue