Re: [PATCH] Bluetooth: Pre-initialize variables in read_local_oob_ext_data_complete()

From: Marcel Holtmann
Date: Wed May 13 2015 - 17:12:07 EST


Hi Geert,

>>>>> net/bluetooth/mgmt.c: In function âread_local_oob_ext_data_completeâ:
>>>>> net/bluetooth/mgmt.c:6474: warning: âr256â may be used uninitialized in this function
>>>>> net/bluetooth/mgmt.c:6474: warning: âh256â may be used uninitialized in this function
>>>>> net/bluetooth/mgmt.c:6474: warning: âr192â may be used uninitialized in this function
>>>>> net/bluetooth/mgmt.c:6474: warning: âh192â may be used uninitialized in this function
>>>>>
>>>>> While these are false positives, the code can be shortened by
>>>>> pre-initializing the hash table pointers and eir_len. This has the side
>>>>> effect of killing the compiler warnings.
>>>>
>>>> can you be a bit specific on which compiler version is this. I fixed one occurrence that seemed valid. However in this case the compiler seems to be just plain stupid. On a gcc 4.9, I am not seeing these for example.
>>>
>>> gcc 4.1.2. As there were too many false positives, these warnings were
>>> disabled in later versions (throwing away the children with the bad water).
>>>
>>> If you don't like my patch, just drop it. I only look at newly
>>> introduced warnings
>>> of this kind anyway.
>>
>> I really do not know what is the best solution here. This is a false positive. And I have been looking at this particular code for a warning that was valid, but we missed initially. But these warnings that you are fixing are clearly false positive.
>
> I only sent patches to fix false positives if I think the patches improve the
> code. As this is a subjective matter, it's up to you as the maintainer to
> decide.
>
>> If this only happens with an old compiler version, I would tend to leave the code as is. Then again, what is the general preferred approach here?
>
> As this is a false positive, it's clearly up to the maintainer to
> decide if the patch
> improves the code or not.

and in this case, I have no idea if I want to bother or not. I really just donât. Since nobody else complained, I might just leave it as is since it really is a false positive.

Regards

Marcel

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