Re: [PATCH 11/99] fbdev/aty: Duplicate video-mode option string

[Thomas Zimmermann]

Hi

Am 06.03.23 um 17:13 schrieb Geert Uytterhoeven:
> Hi Thomas,
>
> Thanks for your patch!
>
> On Mon, Mar 6, 2023 at 5:00 PM Thomas Zimmermann <tzimmermann@xxxxxxx> wrote:
> > Assume that the driver does not own the option string or its substrings
> > and hence duplicate the option string for the video mode. The driver only
> > parses the option string once as part of module initialization, so use
> > a static buffer to store the duplicated mode option. Linux automatically
> > frees the memory upon releasing the module.
>
> Are you sure about that?
> All of this code is inside "#ifndef MODULE".
> In the aty128fb case, the function is not marked __init.
> Enabling these 3 drivers adds 3x256 bytes of static buffer, more
> if you enable more fbdev drivers.

Right. Please see my reply to [00/99].

> > Done in preparation of switching the driver to struct option_iter and
> > constifying the option string.
> >
> > Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
>
> > --- a/drivers/video/fbdev/aty/aty128fb.c
> > +++ b/drivers/video/fbdev/aty/aty128fb.c
> > @@ -1723,7 +1723,17 @@ static int aty128fb_setup(char *options)
> >                          continue;
> >                  }
> >   #endif /* CONFIG_PPC_PMAC */
> > -               mode_option = this_opt;
> > +               {
> > +                       static char mode_option_buf[256];
> > +                       int ret;
> > +
> > +                       ret = snprintf(mode_option_buf, sizeof(mode_option_buf), "%s", this_opt);
> > +                       if (WARN(ret < 0, "aty128: ignoring invalid option, ret=%d\n", ret))
> > +                               continue;
> > +                       if (WARN(ret >= sizeof(mode_option_buf), "aty128fb: option too long\n"))
> > +                               continue;
> > +                       mode_option = mode_option_buf;
> > +               }
> >          }
> >          return 0;
> >   }
> eturn 0;
> >   }
>
> Gr{oetje,eeting}s,
>
>                          Geert

--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Ivo Totev

Attachment: OpenPGP_signature
Description: OpenPGP digital signature