From 9fc3de9c83565fcaa23df74c2fc414bb6e7efb0a Mon Sep 17 00:00:00 2001 From: Arthur Taylor Date: Fri, 4 Feb 2011 13:55:50 -0800 Subject: [PATCH] vt: Add virtual console keyboard mode OFF virtual console: add keyboard mode OFF Add a new mode for the virtual console keyboard OFF in which all input other than shift keys is ignored. Prevents vt input buffers from overflowing when a program opens but doesn't read from a tty, like X11 using evdev for input. Signed-off-by: Arthur Taylor Signed-off-by: Greg Kroah-Hartman --- drivers/tty/vt/keyboard.c | 5 +++-- drivers/tty/vt/vt_ioctl.c | 3 +++ include/linux/kbd_kern.h | 3 ++- include/linux/kd.h | 1 + 4 files changed, 9 insertions(+), 3 deletions(-) diff --git a/drivers/tty/vt/keyboard.c b/drivers/tty/vt/keyboard.c index e95d7876ca6..6dd3c68c13a 100644 --- a/drivers/tty/vt/keyboard.c +++ b/drivers/tty/vt/keyboard.c @@ -654,7 +654,8 @@ static void k_spec(struct vc_data *vc, unsigned char value, char up_flag) if (value >= ARRAY_SIZE(fn_handler)) return; if ((kbd->kbdmode == VC_RAW || - kbd->kbdmode == VC_MEDIUMRAW) && + kbd->kbdmode == VC_MEDIUMRAW || + kbd->kbdmode == VC_OFF) && value != KVAL(K_SAK)) return; /* SAK is allowed even in raw mode */ fn_handler[value](vc); @@ -1295,7 +1296,7 @@ static void kbd_keycode(unsigned int keycode, int down, int hw_raw) if (rc == NOTIFY_STOP) return; - if (raw_mode && type != KT_SPEC && type != KT_SHIFT) + if ((raw_mode || kbd->kbdmode == VC_OFF) && type != KT_SPEC && type != KT_SHIFT) return; (*k_handler[type])(vc, keysym & 0xff, !down); diff --git a/drivers/tty/vt/vt_ioctl.c b/drivers/tty/vt/vt_ioctl.c index 1235ebda6e1..6bcf05bf497 100644 --- a/drivers/tty/vt/vt_ioctl.c +++ b/drivers/tty/vt/vt_ioctl.c @@ -688,6 +688,9 @@ int vt_ioctl(struct tty_struct *tty, struct file * file, kbd->kbdmode = VC_UNICODE; compute_shiftstate(); break; + case K_OFF: + kbd->kbdmode = VC_OFF; + break; default: ret = -EINVAL; goto out; diff --git a/include/linux/kbd_kern.h b/include/linux/kbd_kern.h index 506ad20c18f..4b0761cc7dd 100644 --- a/include/linux/kbd_kern.h +++ b/include/linux/kbd_kern.h @@ -50,11 +50,12 @@ struct kbd_struct { #define VC_CAPSLOCK 2 /* capslock mode */ #define VC_KANALOCK 3 /* kanalock mode */ - unsigned char kbdmode:2; /* one 2-bit value */ + unsigned char kbdmode:3; /* one 3-bit value */ #define VC_XLATE 0 /* translate keycodes using keymap */ #define VC_MEDIUMRAW 1 /* medium raw (keycode) mode */ #define VC_RAW 2 /* raw (scancode) mode */ #define VC_UNICODE 3 /* Unicode mode */ +#define VC_OFF 4 /* disabled mode */ unsigned char modeflags:5; #define VC_APPLIC 0 /* application key mode */ diff --git a/include/linux/kd.h b/include/linux/kd.h index 15f2853ea58..c36d8476db5 100644 --- a/include/linux/kd.h +++ b/include/linux/kd.h @@ -81,6 +81,7 @@ struct unimapinit { #define K_XLATE 0x01 #define K_MEDIUMRAW 0x02 #define K_UNICODE 0x03 +#define K_OFF 0x04 #define KDGKBMODE 0x4B44 /* gets current keyboard mode */ #define KDSKBMODE 0x4B45 /* sets current keyboard mode */ -- 2.46.0