Re: [PATCH] ACPI: Make sure the FADT is at least rev 2 before using the reset register

[Zhang Rui <rui.zhang@intel.com>]

On Sat, 2010-12-11 at 01:57 +0800, Matthew Garrett wrote:
> The reset register was only introduced with version 2 of the FADT, so we
> should check that the FADT revision before trusting its contents.
> 
does the current code break anything?
I'm curious about how you found this bug. :)

thanks,
rui

> Signed-off-by: Matthew Garrett <mjg@redhat.com>
> ---
>  drivers/acpi/reboot.c |    5 +++++
>  1 files changed, 5 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/acpi/reboot.c b/drivers/acpi/reboot.c
> index 4870aaa..a6c77e8b 100644
> --- a/drivers/acpi/reboot.c
> +++ b/drivers/acpi/reboot.c
> @@ -15,6 +15,11 @@ void acpi_reboot(void)
>  
>  	rr = &acpi_gbl_FADT.reset_register;
>  
> +	/* ACPI reset register was only introduced with v2 of the FADT */
> +
> +	if (acpi_gbl_FADT.header.revision < 2)
> +		return;
> +
>  	/* Is the reset register supported? The spec says we should be
>  	 * checking the bit width and bit offset, but Windows ignores
>  	 * these fields */