Commit 086ff846 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'for-5.19/fbdev-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev 

Pull fbdev fixes from Helge Deller:

 - fbcon now prevents switching to screen resolutions which are smaller
   than the font size, and prevents enabling a font which is bigger than
   the current screen resolution. This fixes vmalloc-out-of-bounds
   accesses found by KASAN.

 - Guiling Deng fixed a bug where the centered fbdev logo wasn't
   displayed correctly if the screen size matched the logo size.

 - Hsin-Yi Wang provided a patch to include errno.h to fix build when
   CONFIG_OF isn't enabled.

* tag 'for-5.19/fbdev-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev:
  fbcon: Use fbcon_info_from_console() in fbcon_modechange_possible()
  fbmem: Check virtual screen sizes in fb_set_var()
  fbcon: Prevent that screen size is smaller than font size
  fbcon: Disallow setting font bigger than screen size
  video: of_display_timing.h: include errno.h
  fbdev: fbmem: Fix logo center image dx issue
parents e8a4e1c1 53a6e66b

drivers/video/fbdev/core/fbcon.c

+33 −0
Original line number Diff line number Diff line
@@ -2469,6 +2469,11 @@ static int fbcon_set_font(struct vc_data *vc, struct console_font *font, 
	if (charcount != 256 && charcount != 512)

		return -EINVAL;



	/* font bigger than screen resolution ? */

	if (w > FBCON_SWAP(info->var.rotate, info->var.xres, info->var.yres) ||

	    h > FBCON_SWAP(info->var.rotate, info->var.yres, info->var.xres))

		return -EINVAL;



	/* Make sure drawing engine can handle the font */

	if (!(info->pixmap.blit_x & (1 << (font->width - 1))) ||

	    !(info->pixmap.blit_y & (1 << (font->height - 1))))
@@ -2731,6 +2736,34 @@ void fbcon_update_vcs(struct fb_info *info, bool all) 
}

EXPORT_SYMBOL(fbcon_update_vcs);



/* let fbcon check if it supports a new screen resolution */

int fbcon_modechange_possible(struct fb_info *info, struct fb_var_screeninfo *var)

{

	struct fbcon_ops *ops = info->fbcon_par;

	struct vc_data *vc;

	unsigned int i;



	WARN_CONSOLE_UNLOCKED();



	if (!ops)

		return 0;



	/* prevent setting a screen size which is smaller than font size */

	for (i = first_fb_vc; i <= last_fb_vc; i++) {

		vc = vc_cons[i].d;

		if (!vc || vc->vc_mode != KD_TEXT ||

			   fbcon_info_from_console(i) != info)

			continue;



		if (vc->vc_font.width  > FBCON_SWAP(var->rotate, var->xres, var->yres) ||

		    vc->vc_font.height > FBCON_SWAP(var->rotate, var->yres, var->xres))

			return -EINVAL;

	}



	return 0;

}

EXPORT_SYMBOL_GPL(fbcon_modechange_possible);



int fbcon_mode_deleted(struct fb_info *info,

		       struct fb_videomode *mode)

{

drivers/video/fbdev/core/fbmem.c

+14 −2
Original line number Diff line number Diff line
@@ -511,7 +511,7 @@ static int fb_show_logo_line(struct fb_info *info, int rotate, 


		while (n && (n * (logo->width + 8) - 8 > xres))

			--n;

		image.dx = (xres - n * (logo->width + 8) - 8) / 2;

		image.dx = (xres - (n * (logo->width + 8) - 8)) / 2;

		image.dy = y ?: (yres - logo->height) / 2;

	} else {

		image.dx = 0;
@@ -1017,6 +1017,16 @@ fb_set_var(struct fb_info *info, struct fb_var_screeninfo *var) 
	if (ret)

		return ret;



	/* verify that virtual resolution >= physical resolution */

	if (var->xres_virtual < var->xres ||

	    var->yres_virtual < var->yres) {

		pr_warn("WARNING: fbcon: Driver '%s' missed to adjust virtual screen size (%ux%u vs. %ux%u)\n",

			info->fix.id,

			var->xres_virtual, var->yres_virtual,

			var->xres, var->yres);

		return -EINVAL;

	}



	if ((var->activate & FB_ACTIVATE_MASK) != FB_ACTIVATE_NOW)

		return 0;
@@ -1107,6 +1117,8 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, 
			return -EFAULT;

		console_lock();

		lock_fb_info(info);

		ret = fbcon_modechange_possible(info, &var);

		if (!ret)

			ret = fb_set_var(info, &var);

		if (!ret)

			fbcon_update_vcs(info, var.activate & FB_ACTIVATE_ALL);

include/linux/fbcon.h

+4 −0
Original line number Diff line number Diff line
@@ -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; }

include/video/of_display_timing.h

+2 −0
Original line number Diff line number Diff line
@@ -8,6 +8,8 @@ 
#ifndef __LINUX_OF_DISPLAY_TIMING_H

#define __LINUX_OF_DISPLAY_TIMING_H



#include <linux/errno.h>



struct device_node;

struct display_timing;

struct display_timings;