linux-kernel - Re: [PATCH v2] iio: trigger: free trigger resource correctly

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Date:   Sun, 22 Jan 2017 16:56:39 +0100
From:   Lars-Peter Clausen <lars@...afoo.de>
To:     Jonathan Cameron <jic23@...nel.org>,
        Alison Schofield <amsfield22@...il.com>
Cc:     knaack.h@....de, pmeerw@...erw.net, linux-iio@...r.kernel.org,
        linux-kernel@...r.kernel.org, Michael.Hennerich@...log.com,
        gregkh@...uxfoundation.org, devel@...verdev.osuosl.org
Subject: Re: [PATCH v2] iio: trigger: free trigger resource correctly

On 01/22/2017 03:25 PM, Jonathan Cameron wrote:
> On 20/01/17 03:47, Alison Schofield wrote:
>> These stand-alone trigger drivers were using iio_trigger_put()
>> where they should have been using iio_trigger_free().  The
>> iio_trigger_put() adds a module_put which is bad since they
>> never did a module_get.
>>
>> In the sysfs driver, module_get/put's are used as triggers are
>> added & removed. This extra module_put() occurs on an error path
>> in the probe routine (probably rare).
>>
>> In the bfin-timer & interrupt trigger drivers, the module resources
>> are not explicitly managed, so it's doing a put on something that
>> was never get'd.  It occurs on the probe error path and on the
>> remove path (not so rare).
>>
>> Tested with the sysfs trigger driver.
>> The bfin & interrupt drivers were build tested & inspected only.
>>
>> Signed-off-by: Alison Schofield <amsfield22@...il.com>
> This is certainly more consistent. 
> Lars, could you sanity check as well given the bfin timer is
> in here.

looks good.