Re: [PATCH v4] x86/boot: Use efi_setup_data for searching RSDP on kexec-ed kernel

From: Borislav Petkov
Date: Thu Apr 11 2019 - 04:09:47 EST


On Wed, Apr 10, 2019 at 11:34:51PM +0000, Junichi Nomura wrote:
> But efi_get_rsdp_addr() needs to check whether the kernel was
> kexec booted to avoid accessing invalid EFI table address.
> efi_get_kexec_setup_data_addr() is the only method I know
> to check if it was kexec-booted.

Your v3 had the right approach - you first check if you can get the
address as a kexec-ed kernel. If you do, you use that one and continue
the normal path.

If you don't, you fall back to efi_get_rsdp_addr() and get it directly
from EFI.

And then carve out the functionality you need to call multiple times in
helper functions like __efi_get_rsdp_addr().

Why doesn't that work anymore?

--
Regards/Gruss,
Boris.

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