Re: KASLR causes intermittent boot failures on some systems

[Thomas Garnier]

On Wed, Apr 19, 2017 at 7:34 AM, Dan Williams <dan.j.williams@xxxxxxxxx> wrote:
> Does the randomization ever cross a pgd boundary?

Yes, it can cross a pgd boundary. The original physical memory mapping
might as well but you would need almost 550Gb of memory.

>
> These crashes look very similar to the crashes caused by
> arch_add_memory() racing itself. This issue was fixed in:
>
>     f931ab479dd2 mm: fix devm_memremap_pages crash, use
> mem_hotplug_{begin, done}
>
> ...but that only helps users that call mem_hotplug_begin() to prevent
> concurrent updates.
>

It could be related to page table changes done concurrently or just
done with certain expectations.


-- 
Thomas