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

From: Borislav Petkov <bp@alien8.de>
To: Masayoshi Mizuma <msys.mizuma@gmail.com>
Cc: Baoquan He <bhe@redhat.com>, Ingo Molnar <mingo@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Chao Fan <fanc.fnst@cn.fujitsu.com>,
	linux-kernel@vger.kernel.org, x86@kernel.org,
	linux-efi@vger.kernel.org, linux-acpi@vger.kernel.org,
	mingo@redhat.com, hpa@zytor.com, keescook@chromium.org,
	rjw@rjwysocki.net, lenb@kernel.org, ard.biesheuvel@linaro.org,
	indou.takao@jp.fujitsu.com, caoj.fnst@cn.fujitsu.com
Subject: Re: [PATCH v8 0/3] x86/boot/KASLR: Parse ACPI table and limit kaslr in immovable memory
Date: Tue, 16 Oct 2018 21:11:14 +0200	[thread overview]
Message-ID: <20181016191113.GI5212@zn.tnic> (raw)
In-Reply-To: <20181016151353.punyk7exekut2543@gabell>

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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