[U-Boot] env: fix potential stack overflow in environment functions

[Rob Herring]

On 04/05/2013 11:24 AM, Wolfgang Denk wrote:
> Dear Tom, dear Albert,
> 
> In message <20130405111710.8C04C200589 at gemini.denx.de> I wrote:
>>
>> I hereby request to revert that commit.
> 
> In addition to commit 60d7d5a "env: fix potential stack overflow in
> environment functions" discussed here, I think we should also revert
> commit fcfa696 "ARM: increase lmb stack space reservation to 4KB"
> because it is conceptually broken and just papers over the real
> problems.

Doing so will randomly break any system with a large command or print
buffer. For extra fun, it is dependent on the initrd or dtb image size
in terms of remainder of 4KB multiple.

It is exactly the same code as PPC. It you look at the git history, PPC
made exactly the same change (1 to 4KB increase) around the same time
all the FDT boot code got copied from PPC to ARM. So ARM missed this change.

If the stack is all of RAM, then what address should the initrd and dtb
be copied to?

Rob