On 16/01/18 16:46, Ingo Molnar wrote: > > * Juergen Gross <jgr...@suse.com> wrote: > >> There seem to exist several grub2 versions trashing >> boot_params.hdr.acpi_rsdp_addr. >> >> So don't just believe this address to be valid, but verify it pointing >> to a valid RSDP table. > > Exactly what kind of values do those Grub2 versions put into that field? > Pointer > to something, or random noise?
Looks like random noise. On Mike's system it was 0x000000000151. > Also, what exactly does 'validation' mean, how robustly does it filter out of > spec > uses of the boot protocol? It validates the RSDP has the correct 8 byte eye catcher in it and the checksum of the structure is correct. Searching the RSDP by scanning memory is using the same checks, so I guess this ought to be okay. Odds are about 1 : 2^80 for false positives. Juergen
