Re: [PATCH] x86/efi: Store upper bits of command line buffer address in ext_cmd_line_ptr

[Matt Fleming <matt-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org>]

On Wed, 15 Apr, at 04:32:24PM, Roy Franz wrote:
> Until now, the EFI stub was only setting the 32 bit cmd_line_ptr in
> the setup_header structure, so on 64 bit platforms this could be truncated.
> This patch adds setting the upper bits of the buffer address in
> ext_cmd_line_ptr.  This case was likely never hit, as the allocation
> for this buffer is done at the lowest available address.  Only
> x86_64 kernels have this problem, as the 1-1 mapping mandated
> by EFI ensures that all memory is 32 bit addressable on 32 bit
> platforms.  The EFI stub does not support mixed mode, so the
> 32 bit kernel on 64 bit firmware case does not need to be handled.
> 
> Signed-off-by: Roy Franz <roy.franz-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
> ---
> This is a follow-up to "x86_64/efi: enforce 32 bit address for command line buffer",
> which had the wrong fix to the truncation of address.
> 
>  arch/x86/boot/compressed/eboot.c | 2 ++
>  1 file changed, 2 insertions(+)
 
Looks good to me Roy, thanks applied!

-- 
Matt Fleming, Intel Open Source Technology Center