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

[Wolfgang Denk]

Dear Rob Herring,

In message <515EED36.9090305 at gmail.com> you wrote:
>
> The stack size limit only comes into play when bootm runs and starts
> moving initrd and dtb to high addresses below the stack. At that point,
> the stack size does become limited because only 4KB (recently increase
> from 1KB) of space is reserved. So I had this in mind when I started

BTW - the ARM code is simply broken - see "arch/arm/lib/bootm.c":

 74         lmb_reserve(lmb, sp,
 75                     gd->bd->bi_dram[0].start + gd->bd->bi_dram[0].size - sp);

What if we have more than one memory bank?  Then the computation above
is pretty much random...


Best regards,

Wolfgang Denk

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