Messages in this thread | | | Subject | Re: [PATCH v2 1/1] tracing: trace_remove_event_call() should fail if call/file is in use | From | Steven Rostedt <> | Date | Wed, 31 Jul 2013 12:50:15 -0400 |
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On Mon, 2013-07-29 at 19:50 +0200, Oleg Nesterov wrote: > > +static int probe_remove_event_call(struct ftrace_event_call *call) > +{ > + struct trace_array *tr; > + struct ftrace_event_file *file; > + > +#ifdef CONFIG_PERF_EVENTS > + if (call->perf_refcount) > + return -EBUSY; > +#endif > + do_for_each_event_file(tr, file) { > + if (file->event_call != call) > + continue; > + /* > + * We can't rely on ftrace_event_enable_disable(enable => 0) > + * we are going to do, FTRACE_EVENT_FL_SOFT_MODE can suppress > + * TRACE_REG_UNREGISTER. > + */ > + if (file->flags & FTRACE_EVENT_FL_ENABLED) > + return -EBUSY; > + break;
I'm going to modify the patch to include a comment here about the break being used to go to the next trace_array and not leaving the loop.
-- Steve
> + } while_for_each_event_file(); > + > + __trace_remove_event_call(call); > + > + return 0; > +} > + > /* Remove an event_call */ > -void trace_remove_event_call(struct ftrace_event_call *call) > +int trace_remove_event_call(struct ftrace_event_call *call) > { > + int ret; > + > mutex_lock(&trace_types_lock); > mutex_lock(&event_mutex); > down_write(&trace_event_sem); > - __trace_remove_event_call(call); > + ret = probe_remove_event_call(call); > up_write(&trace_event_sem); > mutex_unlock(&event_mutex); > mutex_unlock(&trace_types_lock); > + > + return ret; > } > > #define for_each_event(event, start, end) \
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