5.4-stable review patch. If anyone has any objections, please let me know.
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From: Helge Deller deller@gmx.de
commit e4fc307d8e24f122402907ebf585248cad52841d upstream.
This reverts commit 864f9963ec6b4b76d104d595ba28110b87158003.
The patch is wrong as it checks vc_origin against vc_screenbuf, while in text mode it should compare against vga_vram_base.
As such it broke VGA text scrolling, which can be reproduced like this: (1) boot a kernel that is configured to use text mode VGA-console (2) type commands: ls -l /usr/bin | less -S (3) scroll up/down with cursor-down/up keys
Reported-by: Jari Ruusu jariruusu@protonmail.com Cc: stable@vger.kernel.org Cc: Yi Yang yiyang13@huawei.com Cc: GONG Ruiqi gongruiqi1@huawei.com Signed-off-by: Helge Deller deller@gmx.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/video/console/vgacon.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/video/console/vgacon.c +++ b/drivers/video/console/vgacon.c @@ -1198,7 +1198,7 @@ static bool vgacon_scroll(struct vc_data c->vc_screenbuf_size - delta); c->vc_origin = vga_vram_end - c->vc_screenbuf_size; vga_rolled_over = 0; - } else if (oldo - delta >= (unsigned long)c->vc_screenbuf) + } else c->vc_origin -= delta; c->vc_scr_end = c->vc_origin + c->vc_screenbuf_size; scr_memsetw((u16 *) (c->vc_origin), c->vc_video_erase_char,