Re: [PATCH] dma-remap: Avoid de-referencing NULL atomic_pool

From: Florian Fainelli
Date: Tue Jun 11 2019 - 12:49:32 EST

On 6/10/19 10:26 PM, Christoph Hellwig wrote:
> Looks good to me. When did this start to show up? Do we need
> to push it to Linus this cycle and cc stable?

You need a really contrived memory map layout to reach that situation,
so I don't think it warrants a stable backport.

For ARM64, this seems to date back to 3.18 with
d4932f9e81ae7a7bf3c3967e48373909b9c98ee5 ("arm64: add atomic pool for
non-coherent and CMA allocations") and for ARM 32-bit, I don't think you
could hit that condition since it would mean no lowmem, which would not
lead to a working kernel.