From: Mikulas Patocka mpatocka@redhat.com
The patch a6dbe4427559 ("vt: perform safe console erase in the right order") introduced a bug. The conditional do_update_region() was replaced by a call to update_region() that does contain the conditional already, but with unwanted extra side effects such as restoring the cursor drawing.
In order to reproduce the bug: - use framebuffer console with the AMDGPU driver - type "links" to start the console www browser - press 'q' and space to exit links
Now the cursor will be permanently visible in the center of the screen. It will stay there until something overwrites it.
The bug goes away if we change update_region() back to the conditional do_update_region().
[ nico: reworded changelog ]
Signed-off-by: Mikulas Patocka mpatocka@redhat.com Reviewed-by: Nicolas Pitre nico@fluxnic.net Cc: stable@vger.kernel.org Fixes: a6dbe4427559 ("vt: perform safe console erase in the right order")
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This is a resent with a proper changelog.
Index: linux-5.0.5/drivers/tty/vt/vt.c =================================================================== --- linux-5.0.5.orig/drivers/tty/vt/vt.c 2019-03-30 19:29:26.000000000 +0100 +++ linux-5.0.5/drivers/tty/vt/vt.c 2019-03-31 13:06:24.000000000 +0200 @@ -1518,7 +1518,8 @@ static void csi_J(struct vc_data *vc, in return; } scr_memsetw(start, vc->vc_video_erase_char, 2 * count); - update_region(vc, (unsigned long) start, count); + if (con_should_update(vc)) + do_update_region(vc, (unsigned long) start, count); vc->vc_need_wrap = 0; }