Re: [PATCH 11/99] fbdev/aty: Duplicate video-mode option string
From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: 2023-03-06 16:24:14
Also in:
dri-devel, lkml
Hi Thomas, Thanks for your patch! On Mon, Mar 6, 2023 at 5:00 PM Thomas Zimmermann [off-list ref] 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.
Done in preparation of switching the driver to struct option_iter and constifying the option string. Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
quoted hunk ↗ jump to hunk
--- 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
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds