Helge Deller
54eaaac622
commit e64242caef upstream.
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+
Signed-off-by: Hugo SIMELIERE <hsimeliere.opensource@witekio.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
17 lines
492 B
C
17 lines
492 B
C
#ifndef _LINUX_FBCON_H
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#define _LINUX_FBCON_H
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#ifdef CONFIG_FRAMEBUFFER_CONSOLE
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void __init fb_console_init(void);
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void __exit fb_console_exit(void);
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int fbcon_modechange_possible(struct fb_info *info,
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struct fb_var_screeninfo *var);
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#else
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static inline void fb_console_init(void) {}
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static inline void fb_console_exit(void) {}
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static inline int fbcon_modechange_possible(struct fb_info *info,
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struct fb_var_screeninfo *var) { return 0; }
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#endif
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#endif /* _LINUX_FBCON_H */
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