Re: [PATCH v2 2/3] kho: skip zero-sized lowmem and global bootmem areas

[Jose A. Perez de Azpillaga]

On 11/4/26 5:50 PM, Mike Rapoport (Microsoft) wrote:
> The lowmem and the global bootmem areas can have zero size, for example
> when none or all of the memory is below ARCH_LOW_ADDRESS_LIMIT, or when
> either of those areas is explicitly set to zero with kho_bootmem=.
> 
> For a zero-sized allocation memblock returns an address without reserving
> anything, and that empty area is recorded in kho_bootmem. If there is no
> memory below ARCH_LOW_ADDRESS_LIMIT, allocation of the empty lowmem area
> fails and KHO gets disabled.
> 
> Extract a helper that checks for zero size and allocates memory from
> memblock, and use it to skip empty areas the same way as empty per-node
> areas are skipped.
> 
> Fixes: 3dc92c311498 ("kexec: add Kexec HandOver (KHO) generation helpers")
> Reported-by: Chen Pei <cp0613@xxxxxxxxxxxxxxxxx>
> Closes: https://lore.kernel.org/all/20261026131851.9942-1-cp0613@xxxxxxxxxxxxxxxxx
> Signed-off-by: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>
Reviewed-by: Jose A. Perez de Azpillaga <azpijr@xxxxxxxxx>

-- 
cheers,
jose a. p-a