From: tingwei@codeaurora•org
To: Suzuki K Poulose <suzuki.poulose@arm•com>
Cc: tsoni@codeaurora•org, saiprakash.ranjan@codeaurora•org,
kim.phillips@arm•com, mathieu.poirier@linaro•org,
alexander.shishkin@linux•intel.com, gregkh@linuxfoundation•org,
coresight@lists•linaro.org, rdunlap@infradead•org,
ykaukab@suse•de, linux@armlinux•org.uk, jinlmao@codeaurora•org,
leo.yan@linaro•org, linux-arm-kernel@lists•infradead.org
Subject: Re: [PATCH v3 19/20] coresight: add try_get_module() in coresight_grab_device()
Date: Thu, 23 Jul 2020 08:19:40 +0800 [thread overview]
Message-ID: <c29e1108b47c63ce77359cae8dbc0c82@codeaurora.org> (raw)
In-Reply-To: <34a3a704-293c-54ac-edfa-17715f419fa4@arm.com>
On 2020-07-22 18:51, Suzuki K Poulose wrote:
> On 07/22/2020 11:49 AM, Suzuki K Poulose wrote:
>> Hi Tingwei,
>>
>> On 07/17/2020 06:45 AM, Tingwei Zhang wrote:
>>> When coresight device is in an active session, driver module of
>>> that device should not be removed. Use try_get_module() in
>>> coresight_grab_device() to prevent module to be unloaded.
>>>
>>
>> Is this really sufficient ? AFAIU, a device could be removed, but the
>> module may still be alive due to the refcount on the module. This
>> could imply that we have stale pointers in the _path_, which could
>> lead to corruption elsewhere. Should we do a get/put_device() instead
>> ?
>
> Also, logically this refcount solution patch must be applied before
> the drivers are made modules to prevent breaking bisection failures.
> So, please re-order the patches in the series to take that into
> consideration.
>
> Suzuki
That's good point. I'll reorder them in next revision.
Thanks,
Tingwei
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next prev parent reply other threads:[~2020-07-23 0:21 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-17 5:45 [PATCH v3 00/20] coresight: allow to build coresight as modules Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 01/20] coresight: cpu_debug: add module name in Kconfig Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 02/20] coresight: cpu_debug: define MODULE_DEVICE_TABLE Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 03/20] coresight: use IS_ENABLED for CONFIGs that may be modules Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 04/20] coresight: add coresight prefix to barrier_pkt Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 05/20] coresight: export global symbols Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 06/20] Allow to build coresight-stm as a module, for ease of development Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 07/20] coresight: allow etm3x to be built as a module Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 08/20] coresight: allow etm4x " Tingwei Zhang
2020-07-17 17:05 ` Mike Leach
2020-07-18 3:25 ` tingwei
2020-07-18 17:38 ` Mike Leach
2020-07-21 14:55 ` Mathieu Poirier
2020-07-21 23:22 ` tingwei
2020-07-20 6:58 ` Sai Prakash Ranjan
2020-07-21 7:03 ` Sai Prakash Ranjan
2020-07-17 5:45 ` [PATCH v3 09/20] coresight: allow etb " Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 10/20] coresight: allow tpiu " Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 11/20] coresight: allow tmc " Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 12/20] coresight: remove multiple init calls from funnel driver Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 13/20] coresight: remove multiple init calls from replicator driver Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 14/20] coresight: allow funnel and replicator drivers to be built as modules Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 15/20] coresight: cti: add function to register cti associate ops Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 16/20] coresight: allow cti to be built as a module Tingwei Zhang
2020-07-20 17:00 ` Mike Leach
2020-07-20 21:07 ` Mike Leach
2020-07-21 16:35 ` Mike Leach
2020-07-21 23:27 ` tingwei
2020-07-17 5:45 ` [PATCH v3 17/20] coresight: tmc-etr: add function to register catu ops Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 18/20] coresight: allow catu drivers to be built as modules Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 19/20] coresight: add try_get_module() in coresight_grab_device() Tingwei Zhang
2020-07-22 10:49 ` Suzuki K Poulose
2020-07-22 10:48 ` Greg KH
2020-07-22 11:26 ` Suzuki K Poulose
2020-07-23 0:18 ` tingwei
2020-07-23 0:35 ` tingwei
2020-07-22 10:51 ` Suzuki K Poulose
2020-07-23 0:19 ` tingwei [this message]
2020-07-23 19:36 ` Mathieu Poirier
2020-07-24 1:17 ` Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 20/20] coresight: allow the coresight core driver to be built as a module Tingwei Zhang
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