linux-kernel - Re: [PATCH] staging/sbe-2t3e3: error path cleanup in t3e3_init

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Message-ID: <CAHdPZaPJKrm2MUjfk7Eo+fXfF6JJT7w++DAkMOPirz9bzZHD6w@mail.gmail.com>
Date:	Thu, 19 Jul 2012 18:33:56 +0530
From:	"devendra.aaru" <devendra.aaru@...il.com>
To:	Dan Carpenter <dan.carpenter@...cle.com>
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	devel@...verdev.osuosl.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] staging/sbe-2t3e3: error path cleanup in t3e3_init_channel

Hi Dan,

On Thu, Jul 19, 2012 at 6:20 PM, Dan Carpenter <dan.carpenter@...cle.com> wrote:
> Cleanup means there are no behavior changes.  This is a bug fix.
>
Thanks Dan, i will put a proper subject line in commit.
> On Thu, Jul 19, 2012 at 06:00:01PM +0530, Devendra Naga wrote:
>>     a) if alloc_hdlcdev fails, we are going into the free_regions,
>> and returning out the err (which is 0 by the prev call),
>>        return -ENOMEM if this function fail.
>>
>>     b) setup_device also can fail, as it calls around the register_hdlc_dev which
>> is again a macro of the register_netdev.
>>
>>        take the error from the setup_device and return it out in error condition
>>
>>     c) request_irq when fails, we are freeing requested mem regions and disabling
>> the pci device(?) and returning err which is agian 0 here.
>>
>>       take the error from request_irq and err path will take care of returning it.
>>
>> as if we return 0 , at the init function, t3e3_init_card, we have a success case
>> and if there are two channels we call this function again, having the result of
>> it completely unknown.
>>
>> This result in having the probe return 0, unloading the driver may (not) cause
>> ambigous result.
>
> These bugs were there before your patch, but we should also be doing
> an unregister_hdlc_device() and a free_netdev().
>
t3e3_remove_channel is called when channel init of channel2 fails, and
i think this cause the double
call to pci_release_region and pci_disable_device,

so i think its better to follow your approach and remove the call to
t3e3_remove_channel and clean all
the things we allocated at the init path itself, rather cleaning them
up when call and a subsequent call to the
t3e3_init_channel fails?

> regards,
> dan carpenter
>

Thanks,
Devendra
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