Re: [PATCH v8 0/3] x86/boot/KASLR: Parse ACPI table and limit kaslr in immovable memory

Borislav Petkov
2018-11-08T10:51:29Z

On Tue, Nov 06, 2018 at 05:21:34PM -0500, Masayoshi Mizuma wrote:
> On Tue, Nov 06, 2018 at 09:45:11PM +0100, Borislav Petkov wrote:
> > On Tue, Nov 06, 2018 at 02:36:38PM -0500, Masayoshi Mizuma wrote:
> > > Yes, I think I can see what you are saying. However, I'm not sure how
> > > I use the setup_data in legacy BIOS environment.
> >
> > What is "legacy BIOS environment" and what does that have to do with
> > setup_data?
>
> My proposed patch [1] is useful only for EFI environment. The patch
> allocates a setup_date structure by efi_call_early() and store the
> KASLR data into the memory area.
>
> +static void setup_kaslr(struct boot_params *params)
> +{
> + struct setup_data *kaslr_data = NULL;
> + struct setup_data *data;
> + unsigned long size;
> + efi_status_t status;
> +
> + size = sizeof(struct setup_data) + sizeof(unsigned long long);
> +
> + status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
> + size, (void **)&kaslr_data);
>
> I'm not sure how I allocate such memory on no EFI environment.

A global definition which doesn't need allocation?

Maybe hpa would have another, better idea...

--
Regards/Gruss,
Boris.

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