Re: [stable 4.19][PATCH 06/17] remoteproc: fix rproc_da_to_va in case of unallocated carveout

[Greg KH]

On Thu, Nov 28, 2019 at 09:49:51AM -0700, Mathieu Poirier wrote:
> From: Loic Pallardy <loic.pallardy@xxxxxx>
> 
> commit 74457c40f97a98142bb13153395d304ad3c85cdd upstream
> 
> With introduction of rproc_alloc_registered_carveouts() which
> delays carveout allocation just before the start of the remote
> processor, rproc_da_to_va() could be called before all carveouts
> are allocated.
> This patch adds a check in rproc_da_to_va() to return NULL if
> carveout is not allocated.
> 
> Fixes: d7c51706d095 ("remoteproc: add alloc ops in rproc_mem_entry struct")

This commit only shows up in 4.20, not 4.19, so why is this patch
relevant for 4.19?

thanks,

greg k-h