| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20260203045457.1049793-3-nico@fluxnic.net>
Date: Mon, 2 Feb 2026 23:52:47 -0500
From: Nicolas Pitre <nico@...xnic.net>
To: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Jiri Slaby <jirislaby@...nel.org>,
Alexey Gladkov <legion@...nel.org>
Cc: Nicolas Pitre <npitre@...libre.com>,
linux-serial@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: [PATCH 2/3] vt: add KT_CSI keysym type for modifier-aware CSI sequences
From: Nicolas Pitre <npitre@...libre.com>
Add a new keysym type KT_CSI that generates CSI tilde sequences with
automatic modifier encoding. The keysym value encodes the CSI parameter
number, producing sequences like ESC [ <value> ~ or ESC [ <value> ; <mod> ~
when Shift, Alt, or Ctrl modifiers are held.
This allows navigation keys (Home, End, Insert, Delete, PgUp, PgDn) and
function keys to generate modifier-aware escape sequences without
consuming string table entries for each modifier combination.
Define key symbols for navigation keys (K_CSI_HOME, K_CSI_END, etc.)
and function keys (K_CSI_F1 through K_CSI_F20) using standard xterm
CSI parameter values.
The modifier encoding follows the xterm convention:
mod = 1 + (shift ? 1 : 0) + (alt ? 2 : 0) + (ctrl ? 4 : 0)
Allowed CSI parameter values range from 0 to 99.
Note: The Linux console historically uses a non-standard double-bracket
format for F1-F5 (ESC [ [ A through ESC [ [ E) rather than the xterm
tilde format (ESC [ 11 ~ through ESC [ 15 ~). The K_CSI_F1 through
K_CSI_F5 definitions use the xterm format. Converting F1-F5 to KT_CSI
would require updating the "linux" terminfo entry to match. Navigation
keys and F6-F20 already use the tilde format and are fully compatible.
Signed-off-by: Nicolas Pitre <npitre@...libre.com>
---
drivers/tty/vt/keyboard.c | 38 ++++++++++++++++++++++++++++++-----
include/uapi/linux/keyboard.h | 29 ++++++++++++++++++++++++++
2 files changed, 62 insertions(+), 5 deletions(-)
diff --git a/drivers/tty/vt/keyboard.c b/drivers/tty/vt/keyboard.c
index dacc2267de6b..0b323cefc647 100644
--- a/drivers/tty/vt/keyboard.c
+++ b/drivers/tty/vt/keyboard.c
@@ -74,7 +74,7 @@ static inline int kbd_defleds(void)
k_self, k_fn, k_spec, k_pad,\
k_dead, k_cons, k_cur, k_shift,\
k_meta, k_ascii, k_lock, k_lowercase,\
- k_slock, k_dead2, k_brl, k_ignore
+ k_slock, k_dead2, k_brl, k_csi
typedef void (k_handler_fn)(struct vc_data *vc, unsigned char value,
char up_flag);
@@ -127,6 +127,7 @@ static const unsigned char max_vals[] = {
[ KT_SLOCK ] = NR_LOCK - 1,
[ KT_DEAD2 ] = 255,
[ KT_BRL ] = NR_BRL - 1,
+ [ KT_CSI ] = 99,
};
static const int NR_TYPES = ARRAY_SIZE(max_vals);
@@ -644,10 +645,6 @@ static void fn_null(struct vc_data *vc)
/*
* Special key handlers
*/
-static void k_ignore(struct vc_data *vc, unsigned char value, char up_flag)
-{
-}
-
static void k_spec(struct vc_data *vc, unsigned char value, char up_flag)
{
if (up_flag)
@@ -1029,6 +1026,37 @@ static void k_brl(struct vc_data *vc, unsigned char value, char up_flag)
}
}
+/*
+ * Handle KT_CSI keysym type: generate CSI tilde sequences with modifier
+ * support. The value encodes the CSI parameter number, producing sequences
+ * like ESC [ <value> ~ or ESC [ <value> ; <mod> ~ when modifiers are held.
+ */
+static void k_csi(struct vc_data *vc, unsigned char value, char up_flag)
+{
+ char buf[10];
+ int i = 0;
+ int mod;
+
+ if (up_flag)
+ return;
+
+ mod = csi_modifier_param();
+
+ buf[i++] = 0x1b;
+ buf[i++] = '[';
+ if (value >= 10)
+ buf[i++] = '0' + value / 10;
+ buf[i++] = '0' + value % 10;
+ if (mod > 1) {
+ buf[i++] = ';';
+ buf[i++] = '0' + mod;
+ }
+ buf[i++] = '~';
+ buf[i] = 0x00;
+
+ puts_queue(vc, buf);
+}
+
#if IS_ENABLED(CONFIG_INPUT_LEDS) && IS_ENABLED(CONFIG_LEDS_TRIGGERS)
struct kbd_led_trigger {
diff --git a/include/uapi/linux/keyboard.h b/include/uapi/linux/keyboard.h
index 36d230cedf12..48ecb0cefb45 100644
--- a/include/uapi/linux/keyboard.h
+++ b/include/uapi/linux/keyboard.h
@@ -41,6 +41,7 @@
#define KT_SLOCK 12
#define KT_DEAD2 13
#define KT_BRL 14
+#define KT_CSI 15 /* CSI sequences with modifier support */
#define K(t,v) (((t)<<8)|(v))
#define KTYP(x) ((x) >> 8)
@@ -461,5 +462,33 @@
#define NR_BRL 11
+/* KT_CSI keys: value is the CSI parameter number for ESC [ <value> ~ */
+#define K_CSI_HOME K(KT_CSI, 1) /* ESC [ 1 ~ */
+#define K_CSI_INSERT K(KT_CSI, 2) /* ESC [ 2 ~ */
+#define K_CSI_DELETE K(KT_CSI, 3) /* ESC [ 3 ~ */
+#define K_CSI_END K(KT_CSI, 4) /* ESC [ 4 ~ */
+#define K_CSI_PGUP K(KT_CSI, 5) /* ESC [ 5 ~ */
+#define K_CSI_PGDN K(KT_CSI, 6) /* ESC [ 6 ~ */
+#define K_CSI_F1 K(KT_CSI, 11) /* ESC [ 11 ~ */
+#define K_CSI_F2 K(KT_CSI, 12) /* ESC [ 12 ~ */
+#define K_CSI_F3 K(KT_CSI, 13) /* ESC [ 13 ~ */
+#define K_CSI_F4 K(KT_CSI, 14) /* ESC [ 14 ~ */
+#define K_CSI_F5 K(KT_CSI, 15) /* ESC [ 15 ~ */
+#define K_CSI_F6 K(KT_CSI, 17) /* ESC [ 17 ~ */
+#define K_CSI_F7 K(KT_CSI, 18) /* ESC [ 18 ~ */
+#define K_CSI_F8 K(KT_CSI, 19) /* ESC [ 19 ~ */
+#define K_CSI_F9 K(KT_CSI, 20) /* ESC [ 20 ~ */
+#define K_CSI_F10 K(KT_CSI, 21) /* ESC [ 21 ~ */
+#define K_CSI_F11 K(KT_CSI, 23) /* ESC [ 23 ~ */
+#define K_CSI_F12 K(KT_CSI, 24) /* ESC [ 24 ~ */
+#define K_CSI_F13 K(KT_CSI, 25) /* ESC [ 25 ~ */
+#define K_CSI_F14 K(KT_CSI, 26) /* ESC [ 26 ~ */
+#define K_CSI_F15 K(KT_CSI, 28) /* ESC [ 28 ~ */
+#define K_CSI_F16 K(KT_CSI, 29) /* ESC [ 29 ~ */
+#define K_CSI_F17 K(KT_CSI, 31) /* ESC [ 31 ~ */
+#define K_CSI_F18 K(KT_CSI, 32) /* ESC [ 32 ~ */
+#define K_CSI_F19 K(KT_CSI, 33) /* ESC [ 33 ~ */
+#define K_CSI_F20 K(KT_CSI, 34) /* ESC [ 34 ~ */
+
#define MAX_DIACR 256
#endif /* _UAPI__LINUX_KEYBOARD_H */
--
2.52.0
Powered by blists - more mailing lists