[POC] Get acpi table to limit memory scope chosen by KASLR to home SB when "movable_node" is specified

[POC] Get acpi table to limit memory scope chosen by KASLR to home SB when "movable_node" is specified

[Chao Fan]

Hi all,

Here is an issue about movable_node and KASLR.
Currently, KASLR works well with "mem=", by which we can limit the scope of
memory chosen by KASLR. But if we use "movable_node" independently without
"mem=", we don't know the scope of memory in the home SB, which will cause
the memory of hotplug SB may be chosen by KASLR.
To solve this problem, I want to do this job:
If "movable_node" is specified, try to get the acpi table and find the scope
of memory in home SB, then set "mem_limit".

The order of getting table is:
boot_params
    \-systab
        \-efi tables
             \-rsdp
                 \-rsdt or xsdt
                      \-acpi root table list
                            \-acpi srat mem affinity

I am not sure if it's OK for community.
If there are any problems, please let me know.
Any comments will be welcome.

Thanks,
Chao Fan

Re: [POC] Get acpi table to limit memory scope chosen by KASLR to home SB when "movable_node" is specified

[Dou Liyang]

Cc ACPI maintainers and mail list

At 08/03/2017 04:51 PM, Chao Fan wrote:
> Hi all,
>
> Here is an issue about movable_node and KASLR.
> Currently, KASLR works well with "mem=", by which we can limit the scope of
> memory chosen by KASLR. But if we use "movable_node" independently without
> "mem=", we don't know the scope of memory in the home SB, which will cause
> the memory of hotplug SB may be chosen by KASLR.
> To solve this problem, I want to do this job:
> If "movable_node" is specified, try to get the acpi table and find the scope
> of memory in home SB, then set "mem_limit".
>
> The order of getting table is:
> boot_params
>     \-systab
>         \-efi tables
>              \-rsdp
>                  \-rsdt or xsdt
>                       \-acpi root table list
>                             \-acpi srat mem affinity
>
> I am not sure if it's OK for community.
> If there are any problems, please let me know.
> Any comments will be welcome.
>
> Thanks,
> Chao Fan
>
>
>

Re: [POC] Get acpi table to limit memory scope chosen by KASLR to home SB when "movable_node" is specified

[Chao Fan]

On Thu, Aug 03, 2017 at 04:59:26PM +0800, Dou Liyang wrote:
>Cc ACPI maintainers and mail list

So many thanks.

>
>At 08/03/2017 04:51 PM, Chao Fan wrote:
>> Hi all,
>> 
>> Here is an issue about movable_node and KASLR.
>> Currently, KASLR works well with "mem=", by which we can limit the scope of
>> memory chosen by KASLR. But if we use "movable_node" independently without
>> "mem=", we don't know the scope of memory in the home SB, which will cause
>> the memory of hotplug SB may be chosen by KASLR.
>> To solve this problem, I want to do this job:
>> If "movable_node" is specified, try to get the acpi table and find the scope
>> of memory in home SB, then set "mem_limit".
>> 
>> The order of getting table is:
>> boot_params
>>     \-systab
>>         \-efi tables
>>              \-rsdp
>>                  \-rsdt or xsdt
>>                       \-acpi root table list
>>                             \-acpi srat mem affinity
>> 

I am not sure if it's good to do this job in this period,
so I want to get the feedback of community.

Thanks,
Chao Fan

>> I am not sure if it's OK for community.
>> If there are any problems, please let me know.
>> Any comments will be welcome.
>> 
>> Thanks,
>> Chao Fan
>> 
>> 
>>