[PATCH 1/3] proc/vmcore: Do not map unaccepted memory

[Dave Hansen]

On 9/6/23 00:39, Adrian Hunter wrote:
> @@ -559,7 +567,8 @@ static int vmcore_remap_oldmem_pfn(struct vm_area_struct *vma,
>  	 * pages without a reason.
>  	 */
>  	idx = srcu_read_lock(&vmcore_cb_srcu);
> -	if (!list_empty(&vmcore_cb_list))
> +	if (!list_empty(&vmcore_cb_list) ||
> +	    range_contains_unaccepted_memory(paddr, paddr + size))
>  		ret = remap_oldmem_pfn_checked(vma, from, pfn, size, prot);
>  	else
>  		ret = remap_oldmem_pfn_range(vma, from, pfn, size, prot);

The whole callback mechanism which fs/proc/vmcore.c::pfn_is_ram()
implements seems to be in place to ensure that there aren't a billion
different "ram" checks in here.

Is there a reason you can't register_vmcore_cb() a callback to check for
unaccepted memory?