RE: [PATCH 1/1] tty: n_gsm: Avoid sleeping during .write() whilst atomic

Starke, Daniel
2023-10-05T14:38:14Z

> > Would something like this tick that box?
> >
> > diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index
> > 1f3aba607cd51..5c1d2fcd5d9e2 100644
> > --- a/drivers/tty/n_gsm.c
> > +++ b/drivers/tty/n_gsm.c
> > @@ -3716,6 +3716,10 @@ static ssize_t gsmld_write(struct tty_struct *tty, struct file *file,
> > if (!gsm)
> > return -ENODEV;
> >
> > + /* The GSM line discipline does not support binding to console */
> > + if (strncmp(tty->name, "tty", 3))
> > + return -EINVAL;
>
> No, that's not going to work, some consoles do not start with "tty" :(

Also, I would recommend exiting as early as possible. E.g. in gsmld_open().
And please retain support for real serial devices (e.g. ttyS, ttyUSB,
ttyACM, ...).

Best regards,
Daniel Starke