Re: [PATCH printk 09/18] serial: kgdboc: Lock console list in probe function

[Doug Anderson]

Hi,

On Fri, Sep 23, 2022 at 5:05 PM John Ogness <john.ogness@xxxxxxxxxxxxx> wrote:
>
> From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
>
> Unprotected list walks are not necessarily safe.
>
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Signed-off-by: John Ogness <john.ogness@xxxxxxxxxxxxx>
> Reviewed-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
> ---
>  drivers/tty/serial/kgdboc.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/tty/serial/kgdboc.c b/drivers/tty/serial/kgdboc.c
> index 79b7db8580e0..af2aa76bae15 100644
> --- a/drivers/tty/serial/kgdboc.c
> +++ b/drivers/tty/serial/kgdboc.c
> @@ -193,7 +193,8 @@ static int configure_kgdboc(void)
>         if (!p)
>                 goto noconfig;
>
> -       for_each_console(cons) {
> +       console_list_lock();
> +       for_each_registered_console(cons) {
>                 int idx;
>                 if (cons->device && cons->device(cons, &idx) == p &&
>                     idx == tty_line) {
> @@ -201,6 +202,7 @@ static int configure_kgdboc(void)
>                         break;
>                 }
>         }
> +       console_list_unlock();

Seems right to me, thanks!

Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>