Patch for fbcon not letting to read console font if it's width is 17-24 (3 bytes pitch)

[Sokalski, Marcin]

staging: drivers: video: fbdev: core: fbcon: Fix getting font from fbcon

The patch fixes the problem of getting fonts from fbcon when the font's
width spans over 3 bytes.
The bug can be reproduced inside linux console running fbcon in following
way:

Set font with width in range 17-24, ie: solar24x32.psfu can be downloaded
from kbd package
> setfont /usr/share/consolefonts/solar24x32.psfu

Try to read it back:
> setfont -O font.psfu

Before the fix, it will diplay:
> get_font: GIO_FONT: Invalid argument

On patched kernel it will output font.psfu file
Now we can confirm it is a valid font file:
> setfont font.psfu

Signed-off-by: Marcin Sokalski <msokalski at novomatic-tech.com>

diff --git a/drivers/video/fbdev/core/fbcon.c
b/drivers/video/fbdev/core/fbcon.c
index 99ecd9a6d844..1f599872cae5 100644
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -1806,18 +1806,15 @@ static int fbcon_get_font(struct vc_data *vc,
struct console_font *font)
  fontdata += j;
  }
  } else if (font->width <= 24) {
- if (font->charcount * (vc->vc_font.height * sizeof(u32)) >
FNTSIZE(fontdata))
+ j = vc->vc_font.height * 3;
+ if (font->charcount * j > FNTSIZE(fontdata))
  return -EINVAL;

  for (i = 0; i < font->charcount; i++) {
- for (j = 0; j < vc->vc_font.height; j++) {
- *data++ = fontdata[0];
- *data++ = fontdata[1];
- *data++ = fontdata[2];
- fontdata += sizeof(u32);
- }
- memset(data, 0, 3 * (32 - j));
- data += 3 * (32 - j);
+ memcpy(data, fontdata, j);
+ memset(data + j, 0, 96 - j);
+ data += 96;
+ fontdata += j;
  }
  } else {
  j = vc->vc_font.height * 4;

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