[Patch 7/9]: vt: Handle up to 2^21 glyphs, rather than 256/512

[Alan Mackenzie <acm@muc.de>]

vt: 32b glyph: 7. Handle up to 2^21 glyphs, rather than 256/512

Replace/supplement tests for number of glyphs with the full
Unicode limits.

Signed-off-by: Alan Mackenzie <acm@muc.de>

diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 8f467b22b799..0c389a564357 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -4905,6 +4961,7 @@ void reset_palette(struct vc_data *vc)
 #define max_font_width	64
 #define max_font_height	128
 #define max_font_glyphs	512
+#define max_font_glyphs21 0x110000
 #define max_font_size	(max_font_glyphs*max_font_width*max_font_height)
 
 static int con_font_get(struct vc_data *vc, struct console_font_op *op)
@@ -4960,17 +5017,23 @@ static int con_font_set(struct vc_data *vc, const struct console_font_op *op)
 
 	if (!op->data)
 		return -EINVAL;
+#ifndef CONFIG_FB_GLYPH_21BIT
 	if (op->charcount > max_font_glyphs)
 		return -EINVAL;
+#else
+	if (op->charcount > max_font_glyphs21)
+		return -EINVAL;
+#endif
 	if (op->width <= 0 || op->width > max_font_width || !op->height ||
 	    op->height > max_font_height)
 		return -EINVAL;
 	if (vpitch < op->height)
 		return -EINVAL;
 	size = DIV_ROUND_UP(op->width, 8) * vpitch * op->charcount;
+#ifndef CONFIG_FB_GLYPH_21BIT
 	if (size > max_font_size)
 		return -ENOSPC;
-
+#endif
 	void *font_data __free(kfree) = font.data = memdup_user(op->data, size);
 	if (IS_ERR(font.data))
 		return PTR_ERR(font.data);
diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
index 9f5c4c101581..18fbf7cf11dd 100644
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -2331,7 +2366,9 @@ static int fbcon_get_font(struct vc_data *vc, struct console_font *font, unsigne
 	font->height = vc->vc_font.height;
 	if (font->height > vpitch)
 		return -ENOSPC;
-	font->charcount = vc->vc_hi_font_mask ? 512 : 256;
+	font->charcount = vc->vc_font.charcount;
+	if (!font->data)
+		return 0;
 
 	return font_data_export(p->fontdata, font, vpitch);
 }
@@ -2420,10 +2468,13 @@ static int fbcon_do_set_font(struct vc_data *vc, int w, int h, int charcount,
 	vc->vc_font.width = w;
 	vc->vc_font.height = h;
 	vc->vc_font.charcount = charcount;
-	if (vc->vc_hi_font_mask && charcount == 256)
-		set_vc_hi_font(vc, false);
-	else if (!vc->vc_hi_font_mask && charcount == 512)
+
+#ifndef CONFIG_FB_GLYPH_21BIT
+	if (charcount == 512 && !vc->vc_hi_font_mask)
 		set_vc_hi_font(vc, true);
+	else if (charcount == 256 && vc->vc_hi_font_mask)
+		set_vc_hi_font(vc, false);
+#endif
 
 	if (resize) {
 		int cols, rows;
@@ -2465,8 +2518,9 @@ static int fbcon_do_set_font(struct vc_data *vc, int w, int h, int charcount,
 }
 
 /*
- *  User asked to set font; we are guaranteed that charcount does not exceed 512
- *  but lets not assume that, since charcount of 512 is small for unicode support.
+ *  User asked to set font; we were once guaranteed that charcount did not
+ *  exceed 512 but that is no longer the case, since charcount of 512 is too
+ *  small for unicode support.
  */
 
 static int fbcon_set_font(struct vc_data *vc, const struct console_font *font,
@@ -2479,10 +2533,18 @@ static int fbcon_set_font(struct vc_data *vc, const struct console_font *font,
 	int i, ret;
 	font_data_t *new_data;
 
-	/* Is there a reason why fbconsole couldn't handle any charcount >256?
-	 * If not this check should be changed to charcount < 256 */
+#ifdef CONFIG_FB_GLYPH_21BIT
+	if (charcount < 256)
+		return -EINVAL;
+#else
+	/* There is no longer any reason why fbconsole can't handle
+	 * any charcount >256, when CONFIG_FB_GLYPH_21BIT is #defined.
+	 * Hence this check has been changed to charcount < 256
+	 * above.
+	 */
 	if (charcount != 256 && charcount != 512)
 		return -EINVAL;
+#endif
 
 	/* font bigger than screen resolution ? */
 	if (w > FBCON_SWAP(info->var.rotate, info->var.xres, info->var.yres) ||


-- 
Alan Mackenzie (Nuremberg, Germany).