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

[Adrian Hunter]

On 7/09/23 18:39, Dave Hansen wrote:
> 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?

Someone asked for the change to be in arch-independent code... ;-)