Commit 23b73654 authored by Michal Januszewski's avatar Michal Januszewski Committed by Linus Torvalds
Browse files

uvesafb: fix selecting mode with the vbemode option 

If the vbemode option is used, uvesafb calls fb_get_mode() without first
setting the resolution in info->var.  This results in a division by zero
in fb_get_mode(), as evidenced e.g.  in [1].  Fix this by ensuring the
info->var structure is populated before fb_get_mode() is called.

[1] http://bugzilla.kernel.org/show_bug.cgi?id=11661#c37



Signed-off-by: default avatarMichal Januszewski <spock@gentoo.org>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent ddb53d48

drivers/video/uvesafb.c

+9 −4
Original line number Diff line number Diff line
@@ -850,6 +850,9 @@ static int __devinit uvesafb_vbe_init_mode(struct fb_info *info) 
	if (vbemode) {

		for (i = 0; i < par->vbe_modes_cnt; i++) {

			if (par->vbe_modes[i].mode_id == vbemode) {

				modeid = i;

				uvesafb_setup_var(&info->var, info,

						&par->vbe_modes[modeid]);

				fb_get_mode(FB_VSYNCTIMINGS | FB_IGNOREMON, 60,

						&info->var, info);

				/*
@@ -857,7 +860,6 @@ static int __devinit uvesafb_vbe_init_mode(struct fb_info *info) 
				 * timings will be used in set_par().

				 */

				info->var.pixclock = 0;

				modeid = i;

				goto gotmode;

			}

		}
@@ -904,8 +906,11 @@ static int __devinit uvesafb_vbe_init_mode(struct fb_info *info) 
			fb_videomode_to_var(&info->var, mode);

		} else {

			modeid = par->vbe_modes[0].mode_id;

			uvesafb_setup_var(&info->var, info,

					&par->vbe_modes[modeid]);

			fb_get_mode(FB_VSYNCTIMINGS | FB_IGNOREMON, 60,

					&info->var, info);



			goto gotmode;

		}

	}
@@ -917,9 +922,9 @@ static int __devinit uvesafb_vbe_init_mode(struct fb_info *info) 
	if (modeid == -1)

		return -EINVAL;



gotmode:

	uvesafb_setup_var(&info->var, info, &par->vbe_modes[modeid]);



gotmode:

	/*

	 * If we are not VBE3.0+ compliant, we're done -- the BIOS will

	 * ignore our timings anyway.

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