Re: [PATCH] memblock: fix crash when reserved memory is not added to memory

[Mike Rapoport <rppt@kernel.org>]

(adding Huang Pei to verify this fixes the crash on loongarch)

On Thu, Jan 18, 2024 at 02:18:53PM +0800, Yajun Deng wrote:
> After commit 61167ad5fecd ("mm: pass nid to reserve_bootmem_region()"),
> we set nid on all reserved pages based on memory region, but some reserved
> memory may not be added to memory on certain architectures. The nid is
> invalid.
> 
> Add the nid check, make sure the nid is valid by early_pfn_to_nid().
> 
> Fixes: 61167ad5fecd ("mm: pass nid to reserve_bootmem_region()")
> Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
> ---
>  mm/memblock.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/mm/memblock.c b/mm/memblock.c
> index abd92869874d..4dcb2ee35eca 100644
> --- a/mm/memblock.c
> +++ b/mm/memblock.c
> @@ -2176,6 +2176,9 @@ static void __init memmap_init_reserved_pages(void)
>  			start = region->base;
>  			end = start + region->size;
>  
> +			if (nid == NUMA_NO_NODE || nid >= MAX_NUMNODES)
> +				nid = early_pfn_to_nid(PFN_DOWN(start));
> +
>  			reserve_bootmem_region(start, end, nid);
>  		}
>  	}
> -- 
> 2.25.1
> 

-- 
Sincerely yours,
Mike.