Re: [PATCH 1/3] auxdisplay: charlcd: fix hex literal ranges for graphics command

From: Willy Tarreau
Date: Sat Feb 10 2018 - 04:20:13 EST


Hi Miguel,

On Sat, Feb 10, 2018 at 09:58:44AM +0100, Miguel Ojeda wrote:
> On Sat, Feb 10, 2018 at 12:50 AM, Robert Abel <rabel@xxxxxxxxxxxxx> wrote:
> > The graphics command expects 16 hexadecimal literals, but would allow characters in range [0-9a-zA-Z] instead of [0-9a-fA-F].
> >
> > Signed-off-by: Robert Abel <rabel@xxxxxxxxxxxxx>
> > ---
> > drivers/auxdisplay/charlcd.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c
> > index 642afd88870b..324d02f9f1c5 100644
> > --- a/drivers/auxdisplay/charlcd.c
> > +++ b/drivers/auxdisplay/charlcd.c
> > @@ -441,9 +441,9 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
> > shift ^= 4;
> > if (*esc >= '0' && *esc <= '9') {
> > value |= (*esc - '0') << shift;
> > - } else if (*esc >= 'A' && *esc <= 'Z') {
> > + } else if (*esc >= 'A' && *esc <= 'F') {
> > value |= (*esc - 'A' + 10) << shift;
> > - } else if (*esc >= 'a' && *esc <= 'z') {
> > + } else if (*esc >= 'a' && *esc <= 'f') {
>
> Willy, Geert: this seems obvious, but do you know if the broader range
> was intended for some reason?

No, I think it was simply a brain fart from me 14 years ago, as I can
find it as well in the original 0.9.0 patch for kernel 2.4!

Ack from me on this patch.

Willy