Re: [PATCH v5 21/36] proc/kcore: include private-node RAM in the kcore RAM map

On Mon, Jul 20, 2026 at 03:34:15PM -0400, Gregory Price wrote:
> The kcore_ram_list bounds its scan at the highest pfn in N_MEMORY.
> 
> As a result, private nodes placed above the last N_MEMORY node, which is
> the common case for device/CXL memory - is truncated out of /proc/kcore.
> 
> Include N_MEMORY_PRIVATE nodes in the scan boundary.  /proc/kcore is
> root-only (CAP_SYS_RAWIO), so this exposes nothing new - it just lets
> a debugger read private-node memory like any other RAM.
> 
> Signed-off-by: Gregory Price <[email protected]>
> ---
>  fs/proc/kcore.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c
> index 390547b992acd..f67194dc2a9b8 100644
> --- a/fs/proc/kcore.c
> +++ b/fs/proc/kcore.c
> @@ -251,11 +251,14 @@ static int kcore_ram_list(struct list_head *list)
>  {
>  	int nid, ret;
>  	unsigned long end_pfn;
> +	nodemask_t mem;
>  
>  	/* Not initialized....update now */
>  	/* find out "max pfn" */
>  	end_pfn = 0;
> -	for_each_node_state(nid, N_MEMORY) {
> +	/* Include private node memory in the scan */
> +	nodes_or(mem, node_states[N_MEMORY], node_states[N_MEMORY_PRIVATE]);
> +	for_each_node_mask(nid, mem) {
>  		unsigned long node_end;
>  		node_end = node_end_pfn(nid);
>  		if (end_pfn < node_end)
> -- 
> 2.53.0-Meta
> 

I'm sure this is the least of your concern with this series, but FWIW:

Acked-by: Omar Sandoval <[email protected]>

If everything goes well, kcore.c is quiet enough that this can probably
just be merged through whatever tree takes the rest of this work.