Re: [PATCH for-4.16] xen/arm: allocate_bank_memory: don't create memory banks of size zero

[Ian Jackson <iwj@xxxxxxxxxxxxxx>]

Julien Grall writes ("Re: [PATCH for-4.16] xen/arm: allocate_bank_memory: don't 
create memory banks of size zero"):
> Instead, it looks like the issue is some part of Xen may fall over if 
> one of the bank is zero-sized. But from the earlier discussion [2], this 
> is just latent. So I think this should be clarified in the commit message.

Yes, please.

Indeed, this is part of:

> Please explain why you would like to include it in 4.16. In particular 
> that as I wrote above, Linux is able to cope with zero-size memory bank.

How is 4.16 bad without this patch ?  And, what might it break ?

What mistakes could have been made in analysis and preparation ?
(In this case the preparation of the patch seems very simple but the
analysis much less so.)

Ian.