[PATCH 04/20] libchip/serial/ns16550* and z8530*: Assert on baud number to avoid divide by 0

[Chris Johns]

On 26/11/2014 10:02 am, Joel Sherrill wrote:
> From: Josh Oguin <josh.oguin at oarcorp.com>
>
> This was flagged by CodeSonar. It should be impossible to get an
> incorrect baud number back but ensure this in debug mode. The _Assert()
> keeps their scanner from evaluating for divide by 0 past this point.
> ---
>   c/src/libchip/serial/ns16550-context.c | 4 ++++
>   c/src/libchip/serial/ns16550.c         | 3 +++
>   c/src/libchip/serial/z85c30.c          | 8 +++++++-
>   3 files changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/c/src/libchip/serial/ns16550-context.c b/c/src/libchip/serial/ns16550-context.c
> index 00ad89c..087627a 100644
> --- a/c/src/libchip/serial/ns16550-context.c
> +++ b/c/src/libchip/serial/ns16550-context.c
> @@ -592,9 +592,13 @@ static bool ns16550_set_attributes(
>
>     /*
>      *  Calculate the baud rate divisor
> +   *
> +   *  Assert ensures there is no division by 0.
>      */
>
>     baud_requested = rtems_termios_baud_to_number(t->c_cflag);
> +  _Assert( baud_requested != 0 );
> +

Should this return an error or the value should be tested in an upper 
layer. I will raise a ticket to have the upper layers reject B0 as a 
baud rate.

Chris