fbcon: remove now unusued 'softback_lines' cursor() argument

mainline inclusion
from mainline-v5.9
commit 06a0df4d
category: bugfix
bugzilla: NA
CVE: CVE-2020-14390

--------------------------------

Since the softscroll code got removed, this argument is always zero and
makes no sense any more.
Tested-by: NYuan Ming <yuanmingbuaa@gmail.com>
Tested-by: NWilly Tarreau <w@1wt.eu>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Reviewed-by: NJason Yan <yanaijie@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/video/fbdev/core/bitblit.c

@@ -234,7 +234,7 @@ static void bit_clear_margins(struct vc_data *vc, struct fb_info *info,
 }
 
 static void bit_cursor(struct vc_data *vc, struct fb_info *info, int mode,
-		       int softback_lines, int fg, int bg)
+		       int fg, int bg)
 {
 	struct fb_cursor cursor;
 	struct fbcon_ops *ops = info->fbcon_par;
@@ -247,15 +247,6 @@ static void bit_cursor(struct vc_data *vc, struct fb_info *info, int mode,
 
 	cursor.set = 0;
 
-	if (softback_lines) {
-		if (y + softback_lines >= vc->vc_rows) {
-			mode = CM_ERASE;
-			ops->cursor_flash = 0;
-			return;
-		} else
-			y += softback_lines;
-	}
-
  	c = scr_readw((u16 *) vc->vc_pos);
 	attribute = get_attribute(info, c);
 	src = vc->vc_font.data + ((c & charmask) * (w * vc->vc_font.height));

drivers/video/fbdev/core/fbcon.c

@@ -376,7 +376,7 @@ static void fb_flashcursor(struct work_struct *work)
 	c = scr_readw((u16 *) vc->vc_pos);
 	mode = (!ops->cursor_flash || ops->cursor_state.enable) ?
 		CM_ERASE : CM_DRAW;
-	ops->cursor(vc, info, mode, 0, get_color(vc, info, c, 1),
+	ops->cursor(vc, info, mode, get_color(vc, info, c, 1),
 		    get_color(vc, info, c, 0));
 	console_unlock();
 }
@@ -1303,7 +1303,7 @@ static void fbcon_cursor(struct vc_data *vc, int mode)
 
 	ops->cursor_flash = (mode == CM_ERASE) ? 0 : 1;
 
-	ops->cursor(vc, info, mode, 0, get_color(vc, info, c, 1),
+	ops->cursor(vc, info, mode, get_color(vc, info, c, 1),
 		    get_color(vc, info, c, 0));
 }
 

drivers/video/fbdev/core/fbcon.h

@@ -62,7 +62,7 @@ struct fbcon_ops {
 	void (*clear_margins)(struct vc_data *vc, struct fb_info *info,
 			      int color, int bottom_only);
 	void (*cursor)(struct vc_data *vc, struct fb_info *info, int mode,
-		       int softback_lines, int fg, int bg);
+		       int fg, int bg);
 	int  (*update_start)(struct fb_info *info);
 	int  (*rotate_font)(struct fb_info *info, struct vc_data *vc);
 	struct fb_var_screeninfo var;  /* copy of the current fb_var_screeninfo */

drivers/video/fbdev/core/fbcon_ccw.c

@@ -219,7 +219,7 @@ static void ccw_clear_margins(struct vc_data *vc, struct fb_info *info,
 }
 
 static void ccw_cursor(struct vc_data *vc, struct fb_info *info, int mode,
-		       int softback_lines, int fg, int bg)
+		       int fg, int bg)
 {
 	struct fb_cursor cursor;
 	struct fbcon_ops *ops = info->fbcon_par;
@@ -236,15 +236,6 @@ static void ccw_cursor(struct vc_data *vc, struct fb_info *info, int mode,
 
 	cursor.set = 0;
 
-	if (softback_lines) {
-		if (y + softback_lines >= vc->vc_rows) {
-			mode = CM_ERASE;
-			ops->cursor_flash = 0;
-			return;
-		} else
-			y += softback_lines;
-	}
-
  	c = scr_readw((u16 *) vc->vc_pos);
 	attribute = get_attribute(info, c);
 	src = ops->fontbuffer + ((c & charmask) * (w * vc->vc_font.width));

drivers/video/fbdev/core/fbcon_cw.c

@@ -202,7 +202,7 @@ static void cw_clear_margins(struct vc_data *vc, struct fb_info *info,
 }
 
 static void cw_cursor(struct vc_data *vc, struct fb_info *info, int mode,
-		      int softback_lines, int fg, int bg)
+		      int fg, int bg)
 {
 	struct fb_cursor cursor;
 	struct fbcon_ops *ops = info->fbcon_par;
@@ -219,15 +219,6 @@ static void cw_cursor(struct vc_data *vc, struct fb_info *info, int mode,
 
 	cursor.set = 0;
 
-	if (softback_lines) {
-		if (y + softback_lines >= vc->vc_rows) {
-			mode = CM_ERASE;
-			ops->cursor_flash = 0;
-			return;
-		} else
-			y += softback_lines;
-	}
-
  	c = scr_readw((u16 *) vc->vc_pos);
 	attribute = get_attribute(info, c);
 	src = ops->fontbuffer + ((c & charmask) * (w * vc->vc_font.width));

drivers/video/fbdev/core/fbcon_ud.c

@@ -249,7 +249,7 @@ static void ud_clear_margins(struct vc_data *vc, struct fb_info *info,
 }
 
 static void ud_cursor(struct vc_data *vc, struct fb_info *info, int mode,
-		      int softback_lines, int fg, int bg)
+		      int fg, int bg)
 {
 	struct fb_cursor cursor;
 	struct fbcon_ops *ops = info->fbcon_par;
@@ -267,15 +267,6 @@ static void ud_cursor(struct vc_data *vc, struct fb_info *info, int mode,
 
 	cursor.set = 0;
 
-	if (softback_lines) {
-		if (y + softback_lines >= vc->vc_rows) {
-			mode = CM_ERASE;
-			ops->cursor_flash = 0;
-			return;
-		} else
-			y += softback_lines;
-	}
-
  	c = scr_readw((u16 *) vc->vc_pos);
 	attribute = get_attribute(info, c);
 	src = ops->fontbuffer + ((c & charmask) * (w * vc->vc_font.height));

drivers/video/fbdev/core/tileblit.c

@@ -80,7 +80,7 @@ static void tile_clear_margins(struct vc_data *vc, struct fb_info *info,
 }
 
 static void tile_cursor(struct vc_data *vc, struct fb_info *info, int mode,
-			int softback_lines, int fg, int bg)
+			int fg, int bg)
 {
 	struct fb_tilecursor cursor;
 	int use_sw = (vc->vc_cursor_type & 0x10);