git: 32bf05ad89aa - main - vt: terminal size can grow too big with small font

[Toomas Soome]

The branch main has been updated by tsoome:

URL: https://cgit.FreeBSD.org/src/commit/?id=32bf05ad89aaa93f4dd27e3721f4cb52cf57fa03

commit 32bf05ad89aaa93f4dd27e3721f4cb52cf57fa03
Author:     Toomas Soome <tsoome at FreeBSD.org>
AuthorDate: 2021-01-21 22:18:56 +0000
Commit:     Toomas Soome <tsoome at FreeBSD.org>
CommitDate: 2021-02-08 16:00:37 +0000

    vt: terminal size can grow too big with small font
    
    vt is using static buffers for on screen data, the buffer size is
    calculated based on maximum supported screen size and 8x16 font.
    
    When using hi-res graphics and very smaller than 8x16 font, we
    need to be careful not to overflow static buffers in vt.
    
    Testing: I did test by building smaller buffers than vt currently is using,
    royger was testing on actual 4k capable hardware.
    
    MFC after: 1 week
    Tested by: royger
---
 sys/dev/vt/vt_core.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/sys/dev/vt/vt_core.c b/sys/dev/vt/vt_core.c
index 05c383829f49..e4a8288962c4 100644
--- a/sys/dev/vt/vt_core.c
+++ b/sys/dev/vt/vt_core.c
@@ -640,8 +640,10 @@ vt_termsize(struct vt_device *vd, struct vt_font *vf, term_pos_t *size)
 		size->tp_row -= vt_logo_sprite_height;
 	size->tp_col = vd->vd_width;
 	if (vf != NULL) {
-		size->tp_row /= vf->vf_height;
-		size->tp_col /= vf->vf_width;
+		size->tp_row = MIN(size->tp_row / vf->vf_height,
+		    PIXEL_HEIGHT(VT_FB_MAX_HEIGHT));
+		size->tp_col = MIN(size->tp_col / vf->vf_width,
+		    PIXEL_WIDTH(VT_FB_MAX_WIDTH));
 	}
 }
 
@@ -660,8 +662,10 @@ vt_termrect(struct vt_device *vd, struct vt_font *vf, term_rect_t *rect)
 		rect->tr_begin.tp_row =
 		    howmany(rect->tr_begin.tp_row, vf->vf_height);
 
-		rect->tr_end.tp_row /= vf->vf_height;
-		rect->tr_end.tp_col /= vf->vf_width;
+		rect->tr_end.tp_row = MIN(rect->tr_end.tp_row / vf->vf_height,
+		    PIXEL_HEIGHT(VT_FB_MAX_HEIGHT));
+		rect->tr_end.tp_col = MIN(rect->tr_end.tp_col / vf->vf_width,
+		    PIXEL_WIDTH(VT_FB_MAX_WIDTH));
 	}
 }
 
@@ -675,8 +679,10 @@ vt_winsize(struct vt_device *vd, struct vt_font *vf, struct winsize *size)
 	size->ws_row = size->ws_ypixel;
 	size->ws_col = size->ws_xpixel = vd->vd_width;
 	if (vf != NULL) {
-		size->ws_row /= vf->vf_height;
-		size->ws_col /= vf->vf_width;
+		size->ws_row = MIN(size->ws_row / vf->vf_height,
+		    PIXEL_HEIGHT(VT_FB_MAX_HEIGHT));
+		size->ws_col = MIN(size->ws_col / vf->vf_width,
+		    PIXEL_WIDTH(VT_FB_MAX_WIDTH));
 	}
 }