Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760180Ab3GaQuT (ORCPT ); Wed, 31 Jul 2013 12:50:19 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:29358 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754094Ab3GaQuR (ORCPT ); Wed, 31 Jul 2013 12:50:17 -0400 X-Authority-Analysis: v=2.0 cv=e9yEuNV/ c=1 sm=0 a=Sro2XwOs0tJUSHxCKfOySw==:17 a=Drc5e87SC40A:10 a=M7EnmfK3RHIA:10 a=5SG0PmZfjMsA:10 a=IkcTkHD0fZMA:10 a=meVymXHHAAAA:8 a=KGjhK52YXX0A:10 a=6No3EKuEBNEA:10 a=V6GUcaXgbJHMPeEY_9AA:9 a=QEXdDO2ut3YA:10 a=Sro2XwOs0tJUSHxCKfOySw==:117 X-Cloudmark-Score: 0 X-Authenticated-User: X-Originating-IP: 67.255.60.225 Message-ID: <1375289415.5418.4.camel@gandalf.local.home> Subject: Re: [PATCH v2 1/1] tracing: trace_remove_event_call() should fail if call/file is in use From: Steven Rostedt To: Oleg Nesterov Cc: Masami Hiramatsu , Alexander Z Lam , Arnaldo Carvalho de Melo , David Sharp , Frederic Weisbecker , Greg Kroah-Hartman , Ingo Molnar , Peter Zijlstra , Srikar Dronamraju , Vaibhav Nagarnaik , "zhangwei(Jovi)" , linux-kernel@vger.kernel.org Date: Wed, 31 Jul 2013 12:50:15 -0400 In-Reply-To: <20130729175033.GB26284@redhat.com> References: <20130729175008.GA26284@redhat.com> <20130729175033.GB26284@redhat.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.4.4-3 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1678 Lines: 61 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) \ -- 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/