Re: [PATCH] [media] ddbridge: fix error handling in module_init_ddbridge()

[Mauro Carvalho Chehab <mchehab@redhat.com>]

Em 15-08-2012 18:00, Lars Hanisch escreveu:
> Hi,
> 
> Am 15.08.2012 22:42, schrieb Alexey Khoroshilov:
>> If pci_register_driver() failed, resources allocated in
>> ddb_class_create() are leaked. The patch fixes it.
>>
>> Found by Linux Driver Verification project (linuxtesting.org).
>>
>> Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
>> ---
>>  drivers/media/dvb/ddbridge/ddbridge-core.c |    6 +++++-
>>  1 file changed, 5 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/media/dvb/ddbridge/ddbridge-core.c b/drivers/media/dvb/ddbridge/ddbridge-core.c
>> index ebf3f05..36aa4e4 100644
>> --- a/drivers/media/dvb/ddbridge/ddbridge-core.c
>> +++ b/drivers/media/dvb/ddbridge/ddbridge-core.c
>> @@ -1705,7 +1705,11 @@ static __init int module_init_ddbridge(void)
>>  	       "Copyright (C) 2010-11 Digital Devices GmbH\n");
>>  	if (ddb_class_create())
>>  		return -1;

This is not right. It should be returning a proper error code.

Could you please patch ddb_class_create() in order to make it to
return the retuned value from IS_ERR() as the error code, and return
it back to the init code?

Ok, I noticed that other parts of the driver are also returning wrong
error codes, but let's fix at least module_init_ddbridge() while you're
looking into this.

>> -	return pci_register_driver(&ddb_pci_driver);
>> +	if (pci_register_driver(&ddb_pci_driver) < 0) {
>> +		ddb_class_destroy();
>> +		return -1;

Again, the correct here would be to store the error on a temp register
and return it, instead of returning -1.
> 
>  Difference to before: the return value of pci_register_driver is not passed through.
>  Is this a problem? I'm just an interested application developer, not a driver developer.

On userspace, ioctl() always return -1 on errors. The error code at "errno"
is wrong, though. Instead of "1", it should be the ones described at the
API spec[1].

[1] http://linuxtv.org/downloads/v4l-dvb-apis/gen_errors.html

> 
> Regards,
> Lars.
> 
>> +	}
>> +	return 0;
>>  }
>>  
>>  static __exit void module_exit_ddbridge(void)
>>
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