Re: POWER: Unexpected fault when writing to brk-allocated memory

[Florian Weimer]

On 11/07/2017 12:15 PM, Kirill A. Shutemov wrote:

> > First of all, using addr and MAP_FIXED to develop our heuristic can
> > never really give unchanged ABI. It's an in-band signal. brk() is a
> > good example that steadily keeps incrementing address, so depending
> > on malloc usage and address space randomization, you will get a brk()
> > that ends exactly at 128T, then the next one will be >
> > DEFAULT_MAP_WINDOW, and it will switch you to 56 bit address space.
>
> No, it won't. You will hit stack first.

That's not actually true on POWER in some cases.  See the process maps I 
posted here:

  <https://marc.info/?l=linuxppc-embedded&m=150988538106263&w=2>

Thanks,
Florian