Re: [PATCH] serial: arc_uart: fix of_iomap leak in `arc_serial_probe`

[Rob Herring]

On Tue, Apr 25, 2023 at 8:27 PM Ke Zhang <m202171830@xxxxxxxxxxx> wrote:
>
> Smatch reports:
>
> drivers/tty/serial/arc_uart.c:631 arc_serial_probe() warn:
> 'port->membase' from of_iomap() not released on lines: 631.
>
> In arc_serial_probe(), if uart_add_one_port() fails,
> port->membase is not released, which would cause a resource leak.
>
> To fix this, I replace of_iomap with devm_of_iomap.

How about use devm_platform_ioremap_resource() instead (or any ioremap
variant) as that is preferred over of_iomap().

Rob

>
> Fixes: 8dbe1d5e09a7 ("serial/arc: inline the probe helper")
> Signed-off-by: Ke Zhang <m202171830@xxxxxxxxxxx>
> Reviewed-by: Dongliang Mu <dzm91@xxxxxxxxxxx>
> ---
> This issue is found by static analysis and remains untested.
> ---
>  drivers/tty/serial/arc_uart.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/tty/serial/arc_uart.c b/drivers/tty/serial/arc_uart.c
> index 59e25f2b6632..be1f3c379382 100644
> --- a/drivers/tty/serial/arc_uart.c
> +++ b/drivers/tty/serial/arc_uart.c
> @@ -606,10 +606,11 @@ static int arc_serial_probe(struct platform_device *pdev)
>         }
>         uart->baud = val;
>
> -       port->membase = of_iomap(np, 0);
> -       if (!port->membase)
> +       port->membase = devm_of_iomap(&pdev->dev, np, 0, NULL);
> +       if (IS_ERR(port->membase)) {
>                 /* No point of dev_err since UART itself is hosed here */
>                 return -ENXIO;

If an errno was returned, you should return that errno and not a different one.

Rob