From: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
To: Namhyung Kim <namhyung@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>,
Steven Rostedt <rostedt@goodmis.org>,
Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
Tom Zanussi <tom.zanussi@linux.intel.com>,
"zhangwei(Jovi)" <jovi.zhangwei@huawei.com>,
linux-kernel@vger.kernel.org,
"yrl.pp-manager.tt@hitachi.com" <yrl.pp-manager.tt@hitachi.com>
Subject: Re: probe_event_disable()->synchronize_sched()
Date: Fri, 04 Jul 2014 10:00:51 +0900 [thread overview]
Message-ID: <53B5FCC3.8010303@hitachi.com> (raw)
In-Reply-To: <87lhsa51kg.fsf@sejong.aot.lge.com>
(2014/07/03 16:44), Namhyung Kim wrote:
> Hi Masami,
>
> On Thu, 03 Jul 2014 14:46:09 +0900, Masami Hiramatsu wrote:
>> One possible scenario is here; someone disables an event and tries to remove
>> it (both will be done by different syscalls). If we don't synchronize
>> the first disabling, the event flag set disabled, but the event itself
>> is not disabled. Thus event handler is still possible to be running
>> somewhere when it is removed.
>
> But, IIUC both of disable and remove path are protected by event_mutex.
> So one cannot see the case of disabled event flag but enabled event, no?
No, the flag is not protect the trace event handler itself.
I meant that running handlers and the flag was not synchronized.
Thank you,
--
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com
next prev parent reply other threads:[~2014-07-04 1:00 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-27 17:01 [PATCH 0/4] tracing/uprobes fixes Oleg Nesterov
2014-06-27 17:01 ` [PATCH 1/4] tracing/uprobes: Revert "Support mix of ftrace and perf" Oleg Nesterov
2014-06-30 5:49 ` Namhyung Kim
2014-06-30 18:48 ` Oleg Nesterov
2014-07-01 19:31 ` probe_event_disable()->synchronize_sched() (Was: tracing/uprobes: Revert "Support mix of ftrace and perf") Oleg Nesterov
2014-07-03 0:54 ` probe_event_disable()->synchronize_sched() Namhyung Kim
2014-07-03 15:41 ` probe_event_disable()->synchronize_sched() Oleg Nesterov
2014-07-03 5:35 ` probe_event_disable()->synchronize_sched() (Was: tracing/uprobes: Revert "Support mix of ftrace and perf") Masami Hiramatsu
2014-07-03 5:46 ` Masami Hiramatsu
2014-07-03 7:44 ` probe_event_disable()->synchronize_sched() Namhyung Kim
2014-07-04 1:00 ` Masami Hiramatsu [this message]
2014-07-04 8:01 ` probe_event_disable()->synchronize_sched() Namhyung Kim
2014-07-03 16:22 ` probe_event_disable()->synchronize_sched() (Was: tracing/uprobes: Revert "Support mix of ftrace and perf") Oleg Nesterov
2014-07-03 17:01 ` __trace_remove_event_dirs() leaks file->filter ? (Was: probe_event_disable()->synchronize_sched()) Oleg Nesterov
2014-07-04 5:21 ` Masami Hiramatsu
2014-07-04 19:38 ` Oleg Nesterov
2014-07-04 4:46 ` probe_event_disable()->synchronize_sched() (Was: tracing/uprobes: Revert "Support mix of ftrace and perf") Masami Hiramatsu
2014-06-30 11:52 ` [PATCH 1/4] tracing/uprobes: Revert "Support mix of ftrace and perf" Masami Hiramatsu
2014-06-30 16:56 ` Srikar Dronamraju
2014-06-27 17:01 ` [PATCH 2/4] uprobes: Change unregister/apply to WARN() if uprobe/consumer is gone Oleg Nesterov
2014-06-30 5:50 ` Namhyung Kim
2014-06-30 16:57 ` Srikar Dronamraju
2014-06-27 17:01 ` [PATCH 3/4] tracing/uprobes: Kill the bogus UPROBE_HANDLER_REMOVE code in uprobe_dispatcher() Oleg Nesterov
2014-06-30 6:03 ` Namhyung Kim
2014-06-30 16:57 ` Srikar Dronamraju
2014-06-27 17:01 ` [PATCH 4/4] tracing/uprobes: Fix the usage of uprobe_buffer_enable() in probe_event_enable() Oleg Nesterov
2014-06-30 6:18 ` Namhyung Kim
2014-06-30 11:49 ` Masami Hiramatsu
2014-06-30 17:04 ` Srikar Dronamraju
2014-06-30 17:21 ` Steven Rostedt
2014-06-30 17:58 ` Oleg Nesterov
2014-06-30 18:22 ` Steven Rostedt
2014-06-30 17:50 ` Oleg Nesterov
2014-06-30 18:01 ` Steven Rostedt
2014-06-30 13:28 ` [PATCH 0/4] tracing/uprobes fixes Steven Rostedt
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