Re: [PATCH v12 1/5] x86/boot: Add get_acpi_rsdp() to parse RSDP in cmdline from KEXEC

From: Borislav Petkov
Date: Wed Dec 05 2018 - 09:58:25 EST


On Thu, Nov 29, 2018 at 04:16:27PM +0800, Chao Fan wrote:
> To fix the conflict between KASLR and memory-hotremove, memory
> information in SRAT table is necessary.
>
> ACPI SRAT (System/Static Resource Affinity Table) can show the details
> about memory ranges, including ranges of memory provided by hot-added
> memory devices. SRAT table must be introduced by RSDP pointer (Root
> System Description Pointer). So RSDP should be found firstly.
>
> When booting form KEXEC/EFI/BIOS, the methods to find RSDP pointer
> are different. When booting from KEXEC, 'acpi_rsdp' may have been
> added to cmdline, so parse the cmdline and find the RSDP pointer.
>
> Signed-off-by: Chao Fan <fanc.fnst@xxxxxxxxxxxxxx>
> ---
> arch/x86/boot/compressed/acpitb.c | 33 +++++++++++++++++++++++++++++++
> arch/x86/boot/compressed/misc.c | 5 +++++
> arch/x86/boot/compressed/misc.h | 4 ++++
> lib/kstrtox.c | 5 +++++
> 4 files changed, 47 insertions(+)
> create mode 100644 arch/x86/boot/compressed/acpitb.c
>
> diff --git a/arch/x86/boot/compressed/acpitb.c b/arch/x86/boot/compressed/acpitb.c
> new file mode 100644
> index 000000000000..614c45655cff
> --- /dev/null
> +++ b/arch/x86/boot/compressed/acpitb.c

Also, I guess calling that file simply "acpi.c" is good enough.

> @@ -0,0 +1,33 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#define BOOT_CTYPE_H
> +#include "misc.h"
> +#include "error.h"
> +
> +#include <linux/efi.h>
> +#include <asm/efi.h>

asm/ headers come after linux/ header.

...

Thx.

--
Regards/Gruss,
Boris.

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