Re: [patch v2 2/3] staging: speakup: check and convert dev name or ser to dev_t

From: Greg Kroah-Hartman
Date: Mon Jun 19 2017 - 01:39:00 EST


On Sun, Jun 18, 2017 at 10:33:35PM -0700, Joe Perches wrote:
> On Mon, 2017-06-19 at 09:15 +0800, Greg Kroah-Hartman wrote:
> > On Sun, Jun 18, 2017 at 09:58:27AM +0100, Okash Khawaja wrote:
> > > This patch adds functionality to validate and convert either a device
> > > name or 'ser' member of synth into dev_t.
> []
> > > --- a/drivers/staging/speakup/spk_ttyio.c
> []
> > > +int ser_to_dev(int ser, dev_t *dev_no)
> > > +{
> > > + if (ser < 0 || ser > (255 - 64)) {
> > > + pr_err("speakup: Invalid ser param. \
> > > + Must be between 0 and 191 inclusive.\n");
> >
> > As Andy pointed out, never do this for a C string, it's not doing what
> > you think it is :)
>
> Well, some guy.
>
> > Worse case, do this like the following:
> > pr_err("speakup: Invalid ser param."
> > "Must be between 0 and 191 inclusive.\n");
>
> Nope, now there's no space between param and Must.
>
> Using string concatenation on multiple lines is error prone.

Ah, yes it is, see, I messed it up! :)