Re: [PATCH] staging: vchiq_arm: Fix missing refcount decrement in error path for fw_node

[Javier Carrasco <javier.carrasco.cruz@gmail.com>]

On 14/10/2024 10:12, Dan Carpenter wrote:
> On Mon, Oct 14, 2024 at 09:59:49AM +0200, Javier Carrasco wrote:
>> This approach is great as long as the maintainer accepts mid-scope
>> variable declaration and the goto instructions get refactored, as stated
>> in cleanup.h.
>>
>> The first point is not being that problematic so far, but the second one
>> is trickier, and we all have to take special care to avoid such issues,
>> even if they don't look dangerous in the current code, because adding a
>> goto where there cleanup attribute is already used can be overlooked as
>> well.
>>
> 
> To be honest, I don't really understand this paragraph.  I think maybe you're
> talking about if we declare the variable at the top and forget to initialize it
> to NULL?  It leads to an uninitialized variable if we exit the function before
> it is initialized.
> 

No, I am talking about declaring the variable mid-scope, and later on
adding a goto before that declaration in a different patch, let's say
far above the variable declaration. As soon as a goto is added, care
must be taken to make sure that we don't have variables with the cleanup
attribute in the scope. Just something to take into account.

>> Actually there are goto instructions in the function, but at least in
>> their current form they are as harmless as useless.
> 
> Yep.  Feel free to delete them.
> 
> regards,
> dan carpenter
>