kernel/linux.git/drivers/tty/vt/vt.c, branch v6.19.11

vt: save/restore unicode screen buffer for alternate screen

2026-03-25T10:13:19+00:00

commit 5eb608319bb56464674a71b4a66ea65c6c435d64 upstream. The alternate screen support added by commit 23743ba64709 ("vt: add support for smput/rmput escape codes") only saves and restores the regular screen buffer (vc_origin), but completely ignores the corresponding unicode screen buffer (vc_uni_lines) creating a messed-up display. Add vc_saved_uni_lines to save the unicode screen buffer when entering the alternate screen, and restore it when leaving. Also ensure proper cleanup in reset_terminal() and vc_deallocate(). Fixes: 23743ba64709 ("vt: add support for smput/rmput escape codes") Cc: stable Signed-off-by: Nicolas Pitre Link: https://patch.msgid.link/5o2p6qp3-91pq-0p17-or02-1oors4417ns7@onlyvoer.pbz Signed-off-by: Greg Kroah-Hartman

tty: vt: do not open code DIV_ROUND_UP()

2025-11-21T17:31:27+00:00

Use the designated DIV_ROUND_UP() macro instead of explicit addition with division. Signed-off-by: Jiri Slaby (SUSE) Link: https://patch.msgid.link/20251119092457.826789-2-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

vt: move vc_saved_screen to within tty allocated judgment

2025-09-12T13:58:41+00:00

Everything starts with the assumption that a tty has been allocated. Therefore, Move it to within the tty allocation check. Fixes: 23743ba64709 ("vt: add support for smput/rmput escape codes") Reported-by: syzbot+f6cb41c144427dc0796a@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=f6cb41c144427dc0796a Tested-by: syzbot+f6cb41c144427dc0796a@syzkaller.appspotmail.com Signed-off-by: Edward Adam Davis Reviewed-by: Jiri Slaby Link: https://lore.kernel.org/r/tencent_CAD45DB31906CF890DBB25AB0DED12205D07@qq.com Signed-off-by: Greg Kroah-Hartman

vt: remove redundant check on vc_mode in con_font_set()

2025-09-06T13:49:52+00:00

Previous commit edab558feba1 ("vt: sort out locking for font handling") move the vc_mode check into console_lock protect, but forget to remove the old check in con_font_set(). Just remove the redundant check. Signed-off-by: Wang Liang Link: https://lore.kernel.org/r/20250904023345.13731-1-wangliang74@huawei.com Signed-off-by: Greg Kroah-Hartman

vt: add support for smput/rmput escape codes

2025-09-06T13:48:32+00:00

Support "\e[?1049h" and "\e[?1049l" escape codes. This patch allows programs to enter and leave alternate screens. This feature is widely available in graphical terminal emulators and mostly used by fullscreen terminal-based user interfaces such as text editors. Most editors such as vim and nano assume this escape code in not supported and will not try to print the escape sequence if TERM=linux. To try out this patch, run `TERM=xterm-256color vim` inside a VT. Signed-off-by: Calixte Pernot Link: https://lore.kernel.org/r/20250825125607.2478-3-calixte.pernot@grenoble-inp.org Signed-off-by: Greg Kroah-Hartman

tty/vt: use guard()s

2025-08-17T10:46:26+00:00

Having all the new guards, use them in the vt code. This improves readability, makes error handling easier, and marks locked portions of code explicit. A local free_page_ptr __free guard is introduced for __get_free_page/free_page (with proper casts). This could be made public in include/. But I am not sure if there are more possible users, so keeping completely private here. Signed-off-by: "Jiri Slaby (SUSE)" Link: https://lore.kernel.org/r/20250814072456.182853-16-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

tty/vt: use guard()s in con_font_set/get() and con_{set,get}_unimap()

2025-08-17T10:46:26+00:00

Having all the new guards, use them in the 8250_rsa code. This improves readability, makes error handling easier, and marks locked portions of code explicit. The new __free()-annotated declarations are moved to the allocation points as is preferred: https://lore.kernel.org/all/CAHk-=wjvh_LUpa=864joG2JJXs3+viO-kLzLidR2JLyMr4MNwA@mail.gmail.com/ Except font_data in con_font_get(). The scope in there would not match the expected lifetime. But the declaration is moved closer. Signed-off-by: "Jiri Slaby (SUSE)" Link: https://lore.kernel.org/r/20250814072456.182853-15-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

vt: add missing notification when switching back to text mode

2025-06-19T11:27:16+00:00

Programs using poll() on /dev/vcsa to be notified when VT changes occur were missing one case: the switch from gfx to text mode. Signed-off-by: Nicolas Pitre Link: https://lore.kernel.org/r/9o5ro928-0pp4-05rq-70p4-ro385n21n723@onlyvoer.pbz Signed-off-by: Greg Kroah-Hartman

vt: bracketed paste support

2025-05-21T11:41:03+00:00

This is comprised of 3 aspects: - Take note of when applications advertise bracketed paste support via "\e[?2004h" and "\e[?2004l". - Insert bracketed paste markers ("\e[200~" and "\e[201~") around pasted content in paste_selection() when bracketed paste is active. - Add TIOCL_GETBRACKETEDPASTE to return bracketed paste status so user space daemons implementing cut-and-paste functionality (e.g. gpm, BRLTTY) may know when to insert bracketed paste markers. Link: https://en.wikipedia.org/wiki/Bracketed-paste Signed-off-by: Nicolas Pitre Reviewed-by: Jiri Slaby Link: https://lore.kernel.org/r/20250520171851.1219676-2-nico@fluxnic.net Signed-off-by: Greg Kroah-Hartman

vt: make use of ucs_get_fallback() when glyph is unavailable

2025-05-21T11:39:45+00:00

Attempt to display a fallback character when given character doesn't have an available glyph. The substitution may not be as good as the original character but still way more helpful than a squared question mark. Example substitutions: À -> A, ç -> c, ø -> o, ─ -> -, © -> C, etc. See gen_ucs_fallback_table.py for a comprehensive list. Signed-off-by: Nicolas Pitre Link: https://lore.kernel.org/r/20250507141535.40655-8-nico@fluxnic.net Signed-off-by: Greg Kroah-Hartman