Messages in this thread | | | From | Junichi Nomura <> | Subject | Re: [PATCH v4] x86/boot: Use efi_setup_data for searching RSDP on kexec-ed kernel | Date | Mon, 15 Apr 2019 07:01:54 +0000 |
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On 4/12/19 10:35 PM, Borislav Petkov wrote: > On Fri, Apr 12, 2019 at 10:49:56AM +0200, Borislav Petkov wrote: >> Now I need to go figure out whether there's a reliable way to know in >> the kexec kernel that it *is* a kexec kernel. > > Actually, thinking about this more, we don't need to know whether the > kernel was kexeced or not. Why? > > Because if it is kexec'ed, kexec(1) passes the required info in > setup_data. Now, if for whatever reason the kexec'ed kernel fails to > parse that EFI info and get the systab to figure out the RDSP, then it > doesn't have any other choice but fail booting. > > Because there's no way it can figure out where the EFI runtime has been > mapped and recover by finding the RDSP from there. > > So I think we're perfectly fine with the old approach: > > if (!pa) > pa = kexec_get_rsdp_addr(); > > if (!pa) > pa = efi_get_rsdp_addr();
OK. Then I'll go back to v3 and make sure to hang when something is wrong during kexec boot on EFI system.
-- Jun'ichi Nomura, NEC Corporation / NEC Solution Innovators, Ltd. | |