diff mbox series

[1/2] tty/sysrq: Extend the sysrq_key_table to cover capital letters

Message ID 20200804162402.2087-2-andrzej.p@collabora.com (mailing list archive)
State Superseded
Headers show
Series Add configurable handler to execute a compound action | expand

Commit Message

Andrzej Pietrasiewicz Aug. 4, 2020, 4:24 p.m. UTC 
All slots in sysrq_key_table[] are either used, reserved or at least
commented with their intended use. This patch adds capital letter versions
available, which means adding 26 more entries.

For already existing SysRq operations the user presses Alt-SysRq-<key>, and
for the newly added ones Alt-Shift-SysRq-<key>.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
---
 Documentation/admin-guide/sysrq.rst |  2 ++
 drivers/tty/sysrq.c                 | 49 +++++++++++++++++++++++++++--
 2 files changed, 49 insertions(+), 2 deletions(-)

Comments

Jiri Slaby Aug. 12, 2020, 11:28 a.m. UTC | #1 
On 04. 08. 20, 18:24, Andrzej Pietrasiewicz wrote:
> All slots in sysrq_key_table[] are either used, reserved or at least
> commented with their intended use. This patch adds capital letter versions
> available, which means adding 26 more entries.
> 
> For already existing SysRq operations the user presses Alt-SysRq-<key>, and
> for the newly added ones Alt-Shift-SysRq-<key>.

And on some keyboards Alt-Fn-Shift-SysRq-<key>. Ugh.

...
> @@ -833,8 +873,13 @@ static bool sysrq_handle_keypress(struct sysrq_state *sysrq,
>  
>  	default:
>  		if (sysrq->active && value && value != 2) {
> +			unsigned char c = sysrq_xlate[code];
> +
>  			sysrq->need_reinject = false;
> -			__handle_sysrq(sysrq_xlate[code], true);
> +			if (sysrq->shift_use != KEY_RESERVED)
> +				if (c >= 'a' && c <= 'z')
> +					c &= ~(1 << 5); /* to uppercase */

c = toupper(c);
instead of the whole if.

> +			__handle_sysrq(c, true);
>  		}
>  		break;
>  	}
> 

thanks,
Jiri Slaby Aug. 12, 2020, 11:32 a.m. UTC | #2 
On 04. 08. 20, 18:24, Andrzej Pietrasiewicz wrote:
> All slots in sysrq_key_table[] are either used, reserved or at least
> commented with their intended use. This patch adds capital letter versions
> available, which means adding 26 more entries.
> 
> For already existing SysRq operations the user presses Alt-SysRq-<key>, and
> for the newly added ones Alt-Shift-SysRq-<key>.

You need to update the help_msg of sysrq_drm_fb_helper_restore_op. It
states sysrq-V (capital V) is the right one. From now on, it isn't

thanks,
diff mbox series

Patch

diff --git a/Documentation/admin-guide/sysrq.rst b/Documentation/admin-guide/sysrq.rst
index e6424d8c5846..67dfa4c29093 100644
--- a/Documentation/admin-guide/sysrq.rst
+++ b/Documentation/admin-guide/sysrq.rst
@@ -79,6 +79,8 @@  On all
 
 		echo t > /proc/sysrq-trigger
 
+The :kbd:`<command key>` is case sensitive.
+
 What are the 'command' keys?
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c
index 7c95afa905a0..52e344bfe8c0 100644
--- a/drivers/tty/sysrq.c
+++ b/drivers/tty/sysrq.c
@@ -442,7 +442,7 @@  static const struct sysrq_key_op sysrq_unrt_op = {
 /* Key Operations table and lock */
 static DEFINE_SPINLOCK(sysrq_key_table_lock);
 
-static const struct sysrq_key_op *sysrq_key_table[36] = {
+static const struct sysrq_key_op *sysrq_key_table[62] = {
 	&sysrq_loglevel_op,		/* 0 */
 	&sysrq_loglevel_op,		/* 1 */
 	&sysrq_loglevel_op,		/* 2 */
@@ -499,6 +499,32 @@  static const struct sysrq_key_op *sysrq_key_table[36] = {
 	/* y: May be registered on sparc64 for global register dump */
 	NULL,				/* y */
 	&sysrq_ftrace_dump_op,		/* z */
+	NULL,				/* A */
+	NULL,				/* B */
+	NULL,				/* C */
+	NULL,				/* D */
+	NULL,				/* E */
+	NULL,				/* F */
+	NULL,				/* G */
+	NULL,				/* H */
+	NULL,				/* I */
+	NULL,				/* J */
+	NULL,				/* K */
+	NULL,				/* L */
+	NULL,				/* M */
+	NULL,				/* N */
+	NULL,				/* O */
+	NULL,				/* P */
+	NULL,				/* Q */
+	NULL,				/* R */
+	NULL,				/* S */
+	NULL,				/* T */
+	NULL,				/* U */
+	NULL,				/* V */
+	NULL,				/* W */
+	NULL,				/* X */
+	NULL,				/* Y */
+	NULL,				/* Z */
 };
 
 /* key2index calculation, -1 on invalid index */
@@ -510,6 +536,8 @@  static int sysrq_key_table_key2index(int key)
 		retval = key - '0';
 	else if ((key >= 'a') && (key <= 'z'))
 		retval = key + 10 - 'a';
+	else if ((key >= 'A') && (key <= 'Z'))
+		retval = key + 36 - 'A';
 	else
 		retval = -1;
 	return retval;
@@ -623,6 +651,8 @@  struct sysrq_state {
 	unsigned long key_down[BITS_TO_LONGS(KEY_CNT)];
 	unsigned int alt;
 	unsigned int alt_use;
+	unsigned int shift;
+	unsigned int shift_use;
 	bool active;
 	bool need_reinject;
 	bool reinjecting;
@@ -807,10 +837,20 @@  static bool sysrq_handle_keypress(struct sysrq_state *sysrq,
 		}
 		break;
 
+	case KEY_LEFTSHIFT:
+	case KEY_RIGHTSHIFT:
+		if (!value)
+			sysrq->shift = KEY_RESERVED;
+		else if (value != 2)
+			sysrq->shift = code;
+		break;
+
 	case KEY_SYSRQ:
 		if (value == 1 && sysrq->alt != KEY_RESERVED) {
 			sysrq->active = true;
 			sysrq->alt_use = sysrq->alt;
+			/* either RESERVED (for released) or actual code */
+			sysrq->shift_use = sysrq->shift;
 			/*
 			 * If nothing else will be pressed we'll need
 			 * to re-inject Alt-SysRq keysroke.
@@ -833,8 +873,13 @@  static bool sysrq_handle_keypress(struct sysrq_state *sysrq,
 
 	default:
 		if (sysrq->active && value && value != 2) {
+			unsigned char c = sysrq_xlate[code];
+
 			sysrq->need_reinject = false;
-			__handle_sysrq(sysrq_xlate[code], true);
+			if (sysrq->shift_use != KEY_RESERVED)
+				if (c >= 'a' && c <= 'z')
+					c &= ~(1 << 5); /* to uppercase */
+			__handle_sysrq(c, true);
 		}
 		break;
 	}