Re: [PATCH] netdev: Use flexible array for trailing private bytes

[Alexander Lobakin]

From: Jakub Kicinski <kuba@xxxxxxxxxx>
Date: Fri, 1 Mar 2024 09:35:17 -0800

> On Fri, 1 Mar 2024 15:30:03 +0100 Alexander Lobakin wrote:
>> I like the idea of declaring priv explicitly rather than doing size +
>> ptr magic. But maybe we could just add this flex array to struct
>> net_device and avoid introducing a new structure.
> 
> 100% I should have linked to the thread that led to Kees's work.
> Adding directly to net_device would be way better but there's
> a handful of drivers which embed the struct.

I think it's okay to embed a struct with flex array at the end as long
as it's not used? Or the compiler will say that the flex array is not at
the end of the structure?

> If we can switch them to dynamic allocation, that'd be great.

It's mega weird to embed &net_device rather than do alloc_*dev() >_<

> And, as you may be alluding to, it removes the need for the WARN_ON()
> entirely as well.

Thanks,
Olek