On Mon, 5 Aug 2024, Jiri Slaby (SUSE) wrote:
> Coverity reports (as CID 1536978) that uart_poll_init() passes
> uninitialized pm_state to uart_change_pm(). It is in case the first 'if'
> takes the true branch (does "goto out;").
>
> Fix this and simplify the function by simple guard(mutex). The code
> needs no labels after this at all. And it is pretty clear that the code
> has not fiddled with pm_state at that point.
>
> Signed-off-by: Jiri Slaby (SUSE) <jirislaby@xxxxxxxxxx>
> Fixes: 5e227ef2aa38 (serial: uart_poll_init() should power on the UART)
> Cc: stable@xxxxxxxxxxxxxxx
> Cc: Douglas Anderson <dianders@xxxxxxxxxxxx>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> ---
> drivers/tty/serial/serial_core.c | 13 ++++++-------
> 1 file changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
> index 3afe77f05abf..d63e9b636e02 100644
> --- a/drivers/tty/serial/serial_core.c
> +++ b/drivers/tty/serial/serial_core.c
> @@ -2690,14 +2690,13 @@ static int uart_poll_init(struct tty_driver *driver, int line, char *options)
> int ret = 0;
>
> tport = &state->port;
> - mutex_lock(&tport->mutex);
> +
> + guard(mutex)(&tport->mutex);
>
> port = uart_port_check(state);
> if (!port || port->type == PORT_UNKNOWN ||
> - !(port->ops->poll_get_char && port->ops->poll_put_char)) {
> - ret = -1;
> - goto out;
> - }
> + !(port->ops->poll_get_char && port->ops->poll_put_char))
> + return -1;
>
> pm_state = state->pm_state;
> uart_change_pm(state, UART_PM_STATE_ON);
> @@ -2717,10 +2716,10 @@ static int uart_poll_init(struct tty_driver *driver, int line, char *options)
> ret = uart_set_options(port, NULL, baud, parity, bits, flow);
> console_list_unlock();
> }
> -out:
> +
> if (ret)
> uart_change_pm(state, pm_state);
> - mutex_unlock(&tport->mutex);
> +
> return ret;
> }
This too needs #include.
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
--
i.
