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[Qemu-devel] [PATCH] console: Fix rendering of VGA underline
From: |
Markus Armbruster |
Subject: |
[Qemu-devel] [PATCH] console: Fix rendering of VGA underline |
Date: |
Fri, 4 Nov 2011 10:38:29 +0100 |
vga_putcharxy()'s underline code sets font_data to 0xffff instead of
0xff. vga_putcharxy() then reads dmask16[0xffff >> 4] and
dmask4[0xffff >> 6]. In practice, these out-of-bounds subscripts
"only" put a few crap bits into the display surface.
For 32 bit pixels, there's no array access. font_data's extra bits go
straight into the display surface.
Broken when commit 6d6f7c28 implemented underline.
Spotted by Coverity.
Signed-off-by: Markus Armbruster <address@hidden>
---
console.c | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/console.c b/console.c
index e43de92..f6fe441 100644
--- a/console.c
+++ b/console.c
@@ -467,7 +467,7 @@ static void vga_putcharxy(DisplayState *ds, int x, int y,
int ch,
font_data = *font_ptr++;
if (t_attrib->uline
&& ((i == FONT_HEIGHT - 2) || (i == FONT_HEIGHT - 3))) {
- font_data = 0xFFFF;
+ font_data = 0xFF;
}
((uint32_t *)d)[0] = (dmask16[(font_data >> 4)] & xorcol) ^ bgcol;
((uint32_t *)d)[1] = (dmask16[(font_data >> 0) & 0xf] & xorcol) ^
bgcol;
@@ -480,7 +480,7 @@ static void vga_putcharxy(DisplayState *ds, int x, int y,
int ch,
font_data = *font_ptr++;
if (t_attrib->uline
&& ((i == FONT_HEIGHT - 2) || (i == FONT_HEIGHT - 3))) {
- font_data = 0xFFFF;
+ font_data = 0xFF;
}
((uint32_t *)d)[0] = (dmask4[(font_data >> 6)] & xorcol) ^ bgcol;
((uint32_t *)d)[1] = (dmask4[(font_data >> 4) & 3] & xorcol) ^
bgcol;
@@ -493,7 +493,7 @@ static void vga_putcharxy(DisplayState *ds, int x, int y,
int ch,
for(i = 0; i < FONT_HEIGHT; i++) {
font_data = *font_ptr++;
if (t_attrib->uline && ((i == FONT_HEIGHT - 2) || (i ==
FONT_HEIGHT - 3))) {
- font_data = 0xFFFF;
+ font_data = 0xFF;
}
((uint32_t *)d)[0] = (-((font_data >> 7)) & xorcol) ^ bgcol;
((uint32_t *)d)[1] = (-((font_data >> 6) & 1) & xorcol) ^ bgcol;
--
1.7.6.4
- [Qemu-devel] [PATCH] console: Fix rendering of VGA underline,
Markus Armbruster <=