viafb: improve pitch handling

This patch adds checks for minimum and maximum pitch size to prevent
invalid settings which could otherwise crash the machine. Also the
alignment is done in a slightly more readable way.

Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: stable@kernel.org
This commit is contained in:
Florian Tobias Schandinat 2011-06-06 01:27:34 +00:00
parent d933990c57
commit 936a3f770b
2 changed files with 13 additions and 3 deletions

View file

@ -28,6 +28,11 @@
#include <linux/types.h>
#define VIA_PITCH_SIZE (1<<3)
#define VIA_PITCH_MAX 0x3FF8
void via_set_primary_address(u32 addr);
void via_set_secondary_address(u32 addr);
void via_set_primary_pitch(u32 pitch);

View file

@ -151,7 +151,8 @@ static void viafb_update_fix(struct fb_info *info)
info->fix.visual =
bpp == 8 ? FB_VISUAL_PSEUDOCOLOR : FB_VISUAL_TRUECOLOR;
info->fix.line_length = (info->var.xres_virtual * bpp / 8 + 7) & ~7;
info->fix.line_length = ALIGN(info->var.xres_virtual * bpp / 8,
VIA_PITCH_SIZE);
}
static void viafb_setup_fixinfo(struct fb_fix_screeninfo *fix,
@ -238,8 +239,12 @@ static int viafb_check_var(struct fb_var_screeninfo *var,
depth = 24;
viafb_fill_var_color_info(var, depth);
line = (var->xres_virtual * var->bits_per_pixel / 8 + 7) & ~7;
if (line * var->yres_virtual > ppar->memsize)
if (var->xres_virtual < var->xres)
var->xres_virtual = var->xres;
line = ALIGN(var->xres_virtual * var->bits_per_pixel / 8,
VIA_PITCH_SIZE);
if (line > VIA_PITCH_MAX || line * var->yres_virtual > ppar->memsize)
return -EINVAL;
/* Based on var passed in to calculate the refresh,