• Matt Fleming's avatar
    x86/efi: Enforce CONFIG_RELOCATABLE for EFI boot stub · 7b2a583a
    Matt Fleming authored
    Without CONFIG_RELOCATABLE the early boot code will decompress the
    kernel to LOAD_PHYSICAL_ADDR. While this may have been fine in the BIOS
    days, that isn't going to fly with UEFI since parts of the firmware
    code/data may be located at LOAD_PHYSICAL_ADDR.
    
    Straying outside of the bounds of the regions we've explicitly requested
    from the firmware will cause all sorts of trouble. Bruno reports that
    his machine resets while trying to decompress the kernel image.
    
    We already go to great pains to ensure the kernel is loaded into a
    suitably aligned buffer, it's just that the address isn't necessarily
    LOAD_PHYSICAL_ADDR, because we can't guarantee that address isn't in-use
    by the firmware.
    
    Explicitly enforce CONFIG_RELOCATABLE for the EFI boot stub, so that we
    can load the kernel at any address with the correct alignment.
    Reported-by: default avatarBruno Prémont <bonbons@linux-vserver.org>
    Tested-by: default avatarBruno Prémont <bonbons@linux-vserver.org>
    Cc: H. Peter Anvin <hpa@zytor.com>
    Cc: <stable@vger.kernel.org>
    Signed-off-by: default avatarMatt Fleming <matt.fleming@intel.com>
    7b2a583a
Kconfig 77.2 KB