Re: [patch 30/41] ACPI EC: Fix regression due to use of uninitialized variable

[Thomas Renninger <trenn@suse.de>]

Hi,

On Wednesday 04 February 2009 19:46:48 Greg KH wrote:
> 2.6.27-stable review patch.  If anyone has any objections, please let us
> know.
Does this one patch cleanly in 2.6.27-stable?
I had it on my list, but this seem to have been introduced after
2.6.27 and I thought I removed this one again?
Or this is a follow up of another fix that should go in?

   Thomas

> ------------------
>
> From: Alexey Starikovskiy <astarikovskiy@suse.de>
>
> commit d21cf3c16b1191f3154a51e0b20c82bf851cc553 upstream.
>
> breakage introduced by following patch
> commit 27663c5855b10af9ec67bc7dfba001426ba21222
> Author: Matthew Wilcox <willy@linux.intel.com>
> Date:   Fri Oct 10 02:22:59 2008 -0400
>
> acpi_evaluate_integer() does not clear passed variable if
> there is an error at evaluation.
> So if we ignore error, we must supply initialized variable.
>
> http://bugzilla.kernel.org/show_bug.cgi?id=11917
>
> Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
> Tested-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
> Signed-off-by: Len Brown <len.brown@intel.com>
> Cc: Thomas Renninger <trenn@suse.de>
> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
>
> ---
>  drivers/acpi/ec.c |    3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> --- a/drivers/acpi/ec.c
> +++ b/drivers/acpi/ec.c
> @@ -769,7 +769,7 @@ static acpi_status
>  ec_parse_device(acpi_handle handle, u32 Level, void *context, void
> **retval) {
>  	acpi_status status;
> -	unsigned long long tmp;
> +	unsigned long long tmp = 0;
>
>  	struct acpi_ec *ec = context;
>  	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
> @@ -784,6 +784,7 @@ ec_parse_device(acpi_handle handle, u32
>  		return status;
>  	ec->gpe = tmp;
>  	/* Use the global lock for all EC transactions? */
> +	tmp = 0;
>  	acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
>  	ec->global_lock = tmp;
>  	ec->handle = handle;