Re: [PATCH v2 1/3] kho: walk bootmem areas in address order

[Jose A. Perez de Azpillaga]

On 11/4/26 5:50 PM, Mike Rapoport (Microsoft) wrote:
> kexec_add_buffer() users may depend on the order in which memory holes are
> searched. For instance, arm64 places the kernel bottom-up and then
> requires the DTB to be above the kernel.
> 
> kho_walk_bootmem() walks the bootmem areas in the order they were
> reserved, so if the kernel lands in a small area at the top of the memory
> there is no room left for the DTB and kexec fails. For example, on an
> arm64 VM with 2G of RAM and kho_bootmem=8M,64M,64M, the lowmem area is
> reserved first at the top of the memory, the kernel image takes most of
> it and kexec fails with
> 
>   kexec_file(Image): Could not find any suitable kernel location!
> 
> Sort the bootmem areas by address and walk them in ascending order, or in
> descending order for top-down searches, like kexec_walk_resources() does.
> 
> Fixes: 3bdecc3c93f9 ("kexec: add KHO support to kexec file loads")
> Signed-off-by: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>
Reviewed-by: Jose A. Perez de Azpillaga <azpijr@xxxxxxxxx>

-- 
cheers,
jose a. p-a