[PATCH 20/45] tty: vt: sanitize arguments of consw::con_clear()

Jiri Slaby (SUSE)
2024-01-18T07:58:42Z

In consw::con_clear():
* Height is always 1, so drop it.
* Offsets and width are always unsigned values, so re-type them as such.

This needs a new __fbcon_clear() in the fbcon code to still handle
height which might not be 1 when called internally.

Note that tests for negative count/width are left in place -- they are
taken care of in the next patches.

And document the hook.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linux-parisc@vger.kernel.org
---
drivers/tty/vt/vt.c | 2 +-
drivers/video/console/dummycon.c | 4 ++--
drivers/video/console/mdacon.c | 15 +++++---------
drivers/video/console/newport_con.c | 6 +++---
drivers/video/console/sticon.c | 8 ++++----
drivers/video/console/vgacon.c | 4 ++--
drivers/video/fbdev/core/fbcon.c | 32 +++++++++++++++++------------
include/linux/console.h | 5 +++--
8 files changed, 39 insertions(+), 37 deletions(-)

diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index eada45683594..a4ee983824d5 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -1590,7 +1590,7 @@ static void csi_X(struct vc_data *vc, unsigned int vpar)
vc_uniscr_clear_line(vc, vc->state.x, count);
scr_memsetw((unsigned short *)vc->vc_pos, vc->vc_video_erase_char, 2 * count);
if (con_should_update(vc))
- vc->vc_sw->con_clear(vc, vc->state.y, vc->state.x, 1, count);
+ vc->vc_sw->con_clear(vc, vc->state.y, vc->state.x, count);
vc->vc_need_wrap = 0;
}

diff --git a/drivers/video/console/dummycon.c b/drivers/video/console/dummycon.c
index f2cef9d9a4b5..0a69d5c216ee 100644
--- a/drivers/video/console/dummycon.c
+++ b/drivers/video/console/dummycon.c
@@ -109,8 +109,8 @@ static void dummycon_init(struct vc_data *vc, bool init)
}

static void dummycon_deinit(struct vc_data *vc) { }
-static void dummycon_clear(struct vc_data *vc, int sy, int sx, int height,
- int width) { }
+static void dummycon_clear(struct vc_data *vc, unsigned int sy, unsigned int sx,
+ unsigned int width) { }
static void dummycon_cursor(struct vc_data *vc, int mode) { }

static bool dummycon_scroll(struct vc_data *vc, unsigned int top,
diff --git a/drivers/video/console/mdacon.c b/drivers/video/console/mdacon.c
index c5b255c96879..1ddbb6cd5b0c 100644
--- a/drivers/video/console/mdacon.c
+++ b/drivers/video/console/mdacon.c
@@ -442,23 +442,18 @@ static void mdacon_putcs(struct vc_data *c, const unsigned short *s,
}
}

-static void mdacon_clear(struct vc_data *c, int y, int x,
- int height, int width)
+static void mdacon_clear(struct vc_data *c, unsigned int y, unsigned int x,
+ unsigned int width)
{
u16 *dest = mda_addr(x, y);
u16 eattr = mda_convert_attr(c->vc_video_erase_char);

- if (width <= 0 || height <= 0)
+ if (width <= 0)
return;

- if (x==0 && width==mda_num_columns) {
- scr_memsetw(dest, eattr, height*width*2);
- } else {
- for (; height > 0; height--, dest+=mda_num_columns)
- scr_memsetw(dest, eattr, width*2);
- }
+ scr_memsetw(dest, eattr, width * 2);
}
-
+
static int mdacon_switch(struct vc_data *c)
{
return 1; /* redrawing needed */
diff --git a/drivers/video/console/newport_con.c b/drivers/video/console/newport_con.c
index 12c64ef47087..55c6106b3507 100644
--- a/drivers/video/console/newport_con.c
+++ b/drivers/video/console/newport_con.c
@@ -346,12 +346,12 @@ static void newport_deinit(struct vc_data *c)
}
}

-static void newport_clear(struct vc_data *vc, int sy, int sx, int height,
- int width)
+static void newport_clear(struct vc_data *vc, unsigned int sy, unsigned int sx,
+ unsigned int width)
{
int xend = ((sx + width) << 3) - 1;
int ystart = ((sy << 4) + topscan) & 0x3ff;
- int yend = (((sy + height) << 4) + topscan - 1) & 0x3ff;
+ int yend = (((sy + 1) << 4) + topscan - 1) & 0x3ff;

if (logo_active)
return;
diff --git a/drivers/video/console/sticon.c b/drivers/video/console/sticon.c
index 0bfeabc3f7c7..d99c2a659bfd 100644
--- a/drivers/video/console/sticon.c
+++ b/drivers/video/console/sticon.c
@@ -300,13 +300,13 @@ static void sticon_deinit(struct vc_data *c)
sticon_set_def_font(i);
}

-static void sticon_clear(struct vc_data *conp, int sy, int sx, int height,
- int width)
+static void sticon_clear(struct vc_data *conp, unsigned int sy, unsigned int sx,
+ unsigned int width)
{
- if (!height || !width)
+ if (!width)
return;

- sti_clear(sticon_sti, sy, sx, height, width,
+ sti_clear(sticon_sti, sy, sx, 1, width,
conp->vc_video_erase_char, font_data[conp->vc_num]);
}

diff --git a/drivers/video/console/vgacon.c b/drivers/video/console/vgacon.c
index 2c0a952ee51a..c6bd4acbe1d2 100644
--- a/drivers/video/console/vgacon.c
+++ b/drivers/video/console/vgacon.c
@@ -1191,8 +1191,8 @@ static bool vgacon_scroll(struct vc_data *c, unsigned int t, unsigned int b,
* The console `switch' structure for the VGA based console
*/

-static void vgacon_clear(struct vc_data *vc, int sy, int sx, int height,
- int width) { }
+static void vgacon_clear(struct vc_data *vc, unsigned int sy, unsigned int sx,
+ unsigned int width) { }
static void vgacon_putc(struct vc_data *vc, int c, int ypos, int xpos) { }
static void vgacon_putcs(struct vc_data *vc, const unsigned short *s,
int count, int ypos, int xpos) { }
diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
index 939c5d893dfb..8a31a36483ea 100644
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -1235,8 +1235,8 @@ static void fbcon_deinit(struct vc_data *vc)
* restriction is simplicity & efficiency at the moment.
*/

-static void fbcon_clear(struct vc_data *vc, int sy, int sx, int height,
- int width)
+static void __fbcon_clear(struct vc_data *vc, unsigned int sy, unsigned int sx,
+ unsigned int height, unsigned int width)
{
struct fb_info *info = fbcon_info_from_console(vc->vc_num);
struct fbcon_ops *ops = info->fbcon_par;
@@ -1273,6 +1273,12 @@ static void fbcon_clear(struct vc_data *vc, int sy, int sx, int height,
ops->clear(vc, info, real_y(p, sy), sx, height, width);
}

+static void fbcon_clear(struct vc_data *vc, unsigned int sy, unsigned int sx,
+ unsigned int width)
+{
+ __fbcon_clear(vc, sy, sx, 1, width);
+}
+
static void fbcon_putcs(struct vc_data *vc, const unsigned short *s,
int count, int ypos, int xpos)
{
@@ -1760,7 +1766,7 @@ static bool fbcon_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
case SCROLL_MOVE:
fbcon_redraw_blit(vc, info, p, t, b - t - count,
count);
- fbcon_clear(vc, b - count, 0, count, vc->vc_cols);
+ __fbcon_clear(vc, b - count, 0, count, vc->vc_cols);
scr_memsetw((unsigned short *) (vc->vc_origin +
vc->vc_size_row *
(b - count)),
@@ -1783,7 +1789,7 @@ static bool fbcon_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
b - t - count, vc->vc_cols);
else
goto redraw_up;
- fbcon_clear(vc, b - count, 0, count, vc->vc_cols);
+ __fbcon_clear(vc, b - count, 0, count, vc->vc_cols);
break;

case SCROLL_PAN_REDRAW:
@@ -1801,7 +1807,7 @@ static bool fbcon_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
vc->vc_rows - b, b);
} else
fbcon_redraw_move(vc, p, t + count, b - t - count, t);
- fbcon_clear(vc, b - count, 0, count, vc->vc_cols);
+ __fbcon_clear(vc, b - count, 0, count, vc->vc_cols);
break;

case SCROLL_PAN_MOVE:
@@ -1824,14 +1830,14 @@ static bool fbcon_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
b - t - count, vc->vc_cols);
else
goto redraw_up;
- fbcon_clear(vc, b - count, 0, count, vc->vc_cols);
+ __fbcon_clear(vc, b - count, 0, count, vc->vc_cols);
break;

case SCROLL_REDRAW:
redraw_up:
fbcon_redraw(vc, t, b - t - count,
count * vc->vc_cols);
- fbcon_clear(vc, b - count, 0, count, vc->vc_cols);
+ __fbcon_clear(vc, b - count, 0, count, vc->vc_cols);
scr_memsetw((unsigned short *) (vc->vc_origin +
vc->vc_size_row *
(b - count)),
@@ -1848,7 +1854,7 @@ static bool fbcon_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
case SCROLL_MOVE:
fbcon_redraw_blit(vc, info, p, b - 1, b - t - count,
-count);
- fbcon_clear(vc, t, 0, count, vc->vc_cols);
+ __fbcon_clear(vc, t, 0, count, vc->vc_cols);
scr_memsetw((unsigned short *) (vc->vc_origin +
vc->vc_size_row *
t),
@@ -1871,7 +1877,7 @@ static bool fbcon_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
b - t - count, vc->vc_cols);
else
goto redraw_down;
- fbcon_clear(vc, t, 0, count, vc->vc_cols);
+ __fbcon_clear(vc, t, 0, count, vc->vc_cols);
break;

case SCROLL_PAN_MOVE:
@@ -1893,7 +1899,7 @@ static bool fbcon_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
b - t - count, vc->vc_cols);
else
goto redraw_down;
- fbcon_clear(vc, t, 0, count, vc->vc_cols);
+ __fbcon_clear(vc, t, 0, count, vc->vc_cols);
break;

case SCROLL_PAN_REDRAW:
@@ -1910,14 +1916,14 @@ static bool fbcon_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
fbcon_redraw_move(vc, p, count, t, 0);
} else
fbcon_redraw_move(vc, p, t, b - t - count, t + count);
- fbcon_clear(vc, t, 0, count, vc->vc_cols);
+ __fbcon_clear(vc, t, 0, count, vc->vc_cols);
break;

case SCROLL_REDRAW:
redraw_down:
fbcon_redraw(vc, b - 1, b - t - count,
-count * vc->vc_cols);
- fbcon_clear(vc, t, 0, count, vc->vc_cols);
+ __fbcon_clear(vc, t, 0, count, vc->vc_cols);
scr_memsetw((unsigned short *) (vc->vc_origin +
vc->vc_size_row *
t),
@@ -2196,7 +2202,7 @@ static void fbcon_generic_blank(struct vc_data *vc, struct fb_info *info,

oldc = vc->vc_video_erase_char;
vc->vc_video_erase_char &= charmask;
- fbcon_clear(vc, 0, 0, vc->vc_rows, vc->vc_cols);
+ __fbcon_clear(vc, 0, 0, vc->vc_rows, vc->vc_cols);
vc->vc_video_erase_char = oldc;
}
}
diff --git a/include/linux/console.h b/include/linux/console.h
index fc9450e0c78f..8fd96a5fca5f 100644
--- a/include/linux/console.h
+++ b/include/linux/console.h
@@ -38,6 +38,7 @@ enum vc_intensity;
*
* @con_init: initialize the console on @vc. @init is true for the very first
* call on this @vc.
+ * @con_clear: erase @count characters at [@x, @y] on @vc. @count >= 1.
* @con_scroll: move lines from @top to @bottom in direction @dir by @lines.
* Return true if no generic handling should be done.
* Invoked by csi_M and printing to the console.
@@ -50,8 +51,8 @@ struct consw {
const char *(*con_startup)(void);
void (*con_init)(struct vc_data *vc, bool init);
void (*con_deinit)(struct vc_data *vc);
- void (*con_clear)(struct vc_data *vc, int sy, int sx, int height,
- int width);
+ void (*con_clear)(struct vc_data *vc, unsigned int y,
+ unsigned int x, unsigned int count);
void (*con_putc)(struct vc_data *vc, int c, int ypos, int xpos);
void (*con_putcs)(struct vc_data *vc, const unsigned short *s,
int count, int ypos, int xpos);
--
2.43.0