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

From: Boris Petkov
Date: Thu Apr 11 2019 - 05:21:36 EST


On April 11, 2019 11:13:03 AM GMT+02:00, Junichi Nomura <j-nomura@xxxxxxxxxxxxx> wrote:
>On 4/11/19 5:37 PM, Borislav Petkov wrote:
>> On Thu, Apr 11, 2019 at 08:16:45AM +0000, Junichi Nomura wrote:
>>> kexec_get_rsdp_addr() might fail on kexec-booted kernel, e.g. if the
>>> setup_data was invalid. In such a case, falling back to
>efi_get_rsdp_addr()
>>> will hit the problem of accessing invalid table pointer again.
>>
>> Then you need to do this:
>>
>> if (kexeced kernel) {
>> addr = kexec_get_rsdp_addr();
>> if (!addr) {
>> /* cannot get address */
>> return -1;
>> }
>>
>> return addr;
>> }
>>
>> and the calling function get_rsdp_addr() must check the return value
>and
>> if it is not 0, return immediately.
>
>Do you mean making get_rsdp_addr() like this?

Does that look like what I've typed above?

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