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| author |   Helge Deller <deller@gmx.de> | 2022-06-25 13:00:34 +0200 |
|---|---|---|
| committer | Helge Deller <deller@gmx.de> | 2022-07-07 10:50:46 +0200 |
| commit | e64242caef18b4a5840b0e7a9bff37abd4f4f933 (patch) | |
| tree | be18c49db4dbefbfa6afe060abe7fd645c6b9e3a /include/linux/fbcon.h | |
| parent | fbcon: Disallow setting font bigger than screen size (diff) | |
| download | linux-dev-e64242caef18b4a5840b0e7a9bff37abd4f4f933.tar.xz linux-dev-e64242caef18b4a5840b0e7a9bff37abd4f4f933.zip | |
fbcon: Prevent that screen size is smaller than font size
We need to prevent that users configure a screen size which is smaller than the
currently selected font size. Otherwise rendering chars on the screen will
access memory outside the graphics memory region.
This patch adds a new function fbcon_modechange_possible() which
implements this check and which later may be extended with other checks
if necessary. The new function is called from the FBIOPUT_VSCREENINFO
ioctl handler in fbmem.c, which will return -EINVAL if userspace asked
for a too small screen size.
Signed-off-by: Helge Deller <deller@gmx.de>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: stable@vger.kernel.org # v5.4+
Diffstat (limited to '')
| -rw-r--r-- | include/linux/fbcon.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/include/linux/fbcon.h b/include/linux/fbcon.h index ff5596dd30f8..2382dec6d6ab 100644 --- a/include/linux/fbcon.h +++ b/include/linux/fbcon.h @@ -15,6 +15,8 @@ void fbcon_new_modelist(struct fb_info *info); void fbcon_get_requirement(struct fb_info *info, struct fb_blit_caps *caps); void fbcon_fb_blanked(struct fb_info *info, int blank); +int fbcon_modechange_possible(struct fb_info *info, + struct fb_var_screeninfo *var); void fbcon_update_vcs(struct fb_info *info, bool all); void fbcon_remap_all(struct fb_info *info); int fbcon_set_con2fb_map_ioctl(void __user *argp); @@ -33,6 +35,8 @@ static inline void fbcon_new_modelist(struct fb_info *info) {} static inline void fbcon_get_requirement(struct fb_info *info, struct fb_blit_caps *caps) {} static inline void fbcon_fb_blanked(struct fb_info *info, int blank) {} +static inline int fbcon_modechange_possible(struct fb_info *info, + struct fb_var_screeninfo *var) { return 0; } static inline void fbcon_update_vcs(struct fb_info *info, bool all) {} static inline void fbcon_remap_all(struct fb_info *info) {} static inline int fbcon_set_con2fb_map_ioctl(void __user *argp) { return 0; } |