Re: [PATCH 1/3] [POWERPC] of_serial: Fix possible null dereference.

["Grant Likely" <grant.likely@secretlab.ca>]

On Thu, Mar 20, 2008 at 8:43 AM, John Linn <john.linn@xilinx.com> wrote:
> From: Stephen Neuendorffer <stephen.neuendorffer@xilinx.com>
>
>  The of_serial driver queries the current-speed property and attempts
>  to use it to register the custom_divisor property of the uart_port.
>  However, if current-speed is not set, then this code will dereference
>  a bad pointer.  The fix is to only set custom_divisor when a
>  current-speed property appears in the device tree.
>
>  Signed-off-by: Stephen Neuendorffer <stephen.neuendorffer@xilinx.com>
>  Signed-off-by: John Linn <john.linn@xilinx.com>

This looks correct and appropriate to me.

Acked-by: Grant Likely <grant.likely@secretlab.ca>

Josh/Arnd, could either of you pick this up?

Cheers,
g.

>  ---
>   drivers/serial/of_serial.c |    4 +++-
>   1 files changed, 3 insertions(+), 1 deletions(-)
>
>  diff --git a/drivers/serial/of_serial.c b/drivers/serial/of_serial.c
>  index a64d858..2efb892 100644
>  --- a/drivers/serial/of_serial.c
>  +++ b/drivers/serial/of_serial.c
>  @@ -56,7 +56,9 @@ static int __devinit of_platform_serial_setup(struct of_device *ofdev,
>         port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP
>                 | UPF_FIXED_PORT;
>         port->dev = &ofdev->dev;
>  -       port->custom_divisor = *clk / (16 * (*spd));
>  +       /* If current-speed was set, then try not to change it. */
>  +       if (spd)
>  +               port->custom_divisor = *clk / (16 * (*spd));
>
>         return 0;
>   }
>  --
>  1.5.2.1
>
>
>
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-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.