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

From: Borislav Petkov
Date: Tue Oct 16 2018 - 15:11:42 EST


On Tue, Oct 16, 2018 at 11:13:54AM -0400, Masayoshi Mizuma wrote:
> Hi Boris, Baoquan and all,
>
> I have created a RFC patch for adjust KASLR padding size.
> This patch is based on Can's v8 patch [1/3], and the Can's patch
> will be changed in the future, so this patch is just RFC.
>
> Welcome to any comments and suggestions. Thanks!

...

> diff --git a/arch/x86/include/uapi/asm/bootparam.h b/arch/x86/include/uapi/asm/bootparam.h
> index a06cbf019744..c987c725e93a 100644
> --- a/arch/x86/include/uapi/asm/bootparam.h
> +++ b/arch/x86/include/uapi/asm/bootparam.h
> @@ -191,7 +191,8 @@ struct boot_params {
> __u8 _pad7[0x290-0x1f1-sizeof(struct setup_header)];
> __u32 edd_mbr_sig_buffer[EDD_MBR_SIG_MAX]; /* 0x290 */
> struct boot_e820_entry e820_table[E820_MAX_ENTRIES_ZEROPAGE]; /* 0x2d0 */
> - __u8 _pad8[48]; /* 0xcd0 */
> + __u8 _pad8[40]; /* 0xcd0 */
> + __u64 possible_mem_addr; /* 0xcf8 */

Where in the example I gave you with add_e820ext() do you see members
being added to struct boot_params?

Take a look at it again pls.

--
Regards/Gruss,
Boris.

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