Input: implement SysRq as a separate input handler
Instead of keeping SysRq support inside of legacy keyboard driver split it out into a separate input handler (filter). This stops most SysRq input events from leaking into evdev clients (some events, such as first SysRq scancode - not keycode - event, are still leaked into both legacy keyboard and evdev). [martinez.javier@gmail.com: fix compile error when CONFIG_MAGIC_SYSRQ is not defined] Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
This commit is contained in:
Dmitry Torokhov
parent
b91c4be730
commit
97f5f0cd8c
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@ -38,7 +38,6 @@
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#include <linux/kbd_kern.h>
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#include <linux/kbd_diacr.h>
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#include <linux/vt_kern.h>
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#include <linux/sysrq.h>
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#include <linux/input.h>
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#include <linux/reboot.h>
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#include <linux/notifier.h>
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@ -82,8 +81,7 @@ void compute_shiftstate(void);
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typedef void (k_handler_fn)(struct vc_data *vc, unsigned char value,
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char up_flag);
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static k_handler_fn K_HANDLERS;
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k_handler_fn *k_handler[16] = { K_HANDLERS };
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EXPORT_SYMBOL_GPL(k_handler);
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static k_handler_fn *k_handler[16] = { K_HANDLERS };
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#define FN_HANDLERS\
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fn_null, fn_enter, fn_show_ptregs, fn_show_mem,\
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@ -147,22 +145,6 @@ static struct ledptr {
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unsigned char valid:1;
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} ledptrs[3];
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/* Simple translation table for the SysRq keys */
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#ifdef CONFIG_MAGIC_SYSRQ
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unsigned char kbd_sysrq_xlate[KEY_MAX + 1] =
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"\000\0331234567890-=\177\t" /* 0x00 - 0x0f */
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"qwertyuiop[]\r\000as" /* 0x10 - 0x1f */
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"dfghjkl;'`\000\\zxcv" /* 0x20 - 0x2f */
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"bnm,./\000*\000 \000\201\202\203\204\205" /* 0x30 - 0x3f */
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"\206\207\210\211\212\000\000789-456+1" /* 0x40 - 0x4f */
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"230\177\000\000\213\214\000\000\000\000\000\000\000\000\000\000" /* 0x50 - 0x5f */
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"\r\000/"; /* 0x60 - 0x6f */
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static int sysrq_down;
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static int sysrq_alt_use;
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#endif
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static int sysrq_alt;
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/*
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* Notifier list for console keyboard events
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*/
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@ -1108,7 +1090,8 @@ static int emulate_raw(struct vc_data *vc, unsigned int keycode,
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* pressing PrtSc/SysRq alone, but simply 0x54
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* when pressing Alt+PrtSc/SysRq.
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*/
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if (sysrq_alt) {
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if (test_bit(KEY_LEFTALT, key_down) ||
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test_bit(KEY_RIGHTALT, key_down)) {
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put_queue(vc, 0x54 | up_flag);
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} else {
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put_queue(vc, 0xe0);
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@ -1176,8 +1159,6 @@ static void kbd_keycode(unsigned int keycode, int down, int hw_raw)
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kbd = kbd_table + vc->vc_num;
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if (keycode == KEY_LEFTALT || keycode == KEY_RIGHTALT)
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sysrq_alt = down ? keycode : 0;
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#ifdef CONFIG_SPARC
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if (keycode == KEY_STOP)
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sparc_l1_a_state = down;
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@ -1190,21 +1171,6 @@ static void kbd_keycode(unsigned int keycode, int down, int hw_raw)
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if (keycode < BTN_MISC && printk_ratelimit())
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printk(KERN_WARNING "keyboard.c: can't emulate rawmode for keycode %d\n", keycode);
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#ifdef CONFIG_MAGIC_SYSRQ /* Handle the SysRq Hack */
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if (keycode == KEY_SYSRQ && (sysrq_down || (down == 1 && sysrq_alt))) {
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if (!sysrq_down) {
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sysrq_down = down;
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sysrq_alt_use = sysrq_alt;
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}
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return;
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}
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if (sysrq_down && !down && keycode == sysrq_alt_use)
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sysrq_down = 0;
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if (sysrq_down && down && !rep) {
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handle_sysrq(kbd_sysrq_xlate[keycode], tty);
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return;
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}
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#endif
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#ifdef CONFIG_SPARC
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if (keycode == KEY_A && sparc_l1_a_state) {
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sparc_l1_a_state = 0;
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@ -1,7 +1,4 @@
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/* -*- linux-c -*-
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*
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* $Id: sysrq.c,v 1.15 1998/08/23 14:56:41 mj Exp $
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*
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/*
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* Linux Magic System Request Key Hacks
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*
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* (c) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
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@ -10,8 +7,13 @@
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* (c) 2000 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
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* overhauled to use key registration
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* based upon discusions in irc://irc.openprojects.net/#kernelnewbies
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*
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* Copyright (c) 2010 Dmitry Torokhov
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* Input handler conversion
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/sched.h>
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#include <linux/interrupt.h>
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#include <linux/mm.h>
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@ -39,33 +41,34 @@
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#include <linux/hrtimer.h>
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#include <linux/oom.h>
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#include <linux/slab.h>
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#include <linux/input.h>
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#include <asm/ptrace.h>
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#include <asm/irq_regs.h>
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/* Whether we react on sysrq keys or just ignore them */
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int __read_mostly __sysrq_enabled = 1;
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static int __read_mostly sysrq_enabled = 1;
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static bool __read_mostly sysrq_always_enabled;
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static int __read_mostly sysrq_always_enabled;
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int sysrq_on(void)
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static bool sysrq_on(void)
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{
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return __sysrq_enabled || sysrq_always_enabled;
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return sysrq_enabled || sysrq_always_enabled;
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}
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/*
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* A value of 1 means 'all', other nonzero values are an op mask:
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*/
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static inline int sysrq_on_mask(int mask)
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static bool sysrq_on_mask(int mask)
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{
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return sysrq_always_enabled || __sysrq_enabled == 1 ||
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(__sysrq_enabled & mask);
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return sysrq_always_enabled ||
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sysrq_enabled == 1 ||
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(sysrq_enabled & mask);
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}
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static int __init sysrq_always_enabled_setup(char *str)
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{
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sysrq_always_enabled = 1;
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printk(KERN_INFO "debug: sysrq always enabled.\n");
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sysrq_always_enabled = true;
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pr_info("sysrq always enabled.\n");
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return 1;
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}
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@ -76,6 +79,7 @@ __setup("sysrq_always_enabled", sysrq_always_enabled_setup);
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static void sysrq_handle_loglevel(int key, struct tty_struct *tty)
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{
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int i;
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i = key - '0';
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console_loglevel = 7;
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printk("Loglevel set to %d\n", i);
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@ -101,7 +105,7 @@ static struct sysrq_key_op sysrq_SAK_op = {
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.enable_mask = SYSRQ_ENABLE_KEYBOARD,
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};
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#else
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#define sysrq_SAK_op (*(struct sysrq_key_op *)0)
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#define sysrq_SAK_op (*(struct sysrq_key_op *)NULL)
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#endif
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#ifdef CONFIG_VT
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@ -119,7 +123,7 @@ static struct sysrq_key_op sysrq_unraw_op = {
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.enable_mask = SYSRQ_ENABLE_KEYBOARD,
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};
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#else
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#define sysrq_unraw_op (*(struct sysrq_key_op *)0)
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#define sysrq_unraw_op (*(struct sysrq_key_op *)NULL)
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#endif /* CONFIG_VT */
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static void sysrq_handle_crash(int key, struct tty_struct *tty)
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@ -195,7 +199,7 @@ static struct sysrq_key_op sysrq_showlocks_op = {
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.action_msg = "Show Locks Held",
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};
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#else
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#define sysrq_showlocks_op (*(struct sysrq_key_op *)0)
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#define sysrq_showlocks_op (*(struct sysrq_key_op *)NULL)
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#endif
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#ifdef CONFIG_SMP
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@ -298,7 +302,7 @@ static struct sysrq_key_op sysrq_ftrace_dump_op = {
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.enable_mask = SYSRQ_ENABLE_DUMP,
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};
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#else
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#define sysrq_ftrace_dump_op (*(struct sysrq_key_op *)0)
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#define sysrq_ftrace_dump_op (*(struct sysrq_key_op *)NULL)
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#endif
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static void sysrq_handle_showmem(int key, struct tty_struct *tty)
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@ -477,6 +481,7 @@ struct sysrq_key_op *__sysrq_get_key_op(int key)
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i = sysrq_key_table_key2index(key);
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if (i != -1)
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op_p = sysrq_key_table[i];
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return op_p;
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}
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@ -488,11 +493,7 @@ static void __sysrq_put_key_op(int key, struct sysrq_key_op *op_p)
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sysrq_key_table[i] = op_p;
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}
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/*
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* This is the non-locking version of handle_sysrq. It must/can only be called
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* by sysrq key handlers, as they are inside of the lock
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*/
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void __handle_sysrq(int key, struct tty_struct *tty, int check_mask)
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static void __handle_sysrq(int key, struct tty_struct *tty, int check_mask)
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{
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struct sysrq_key_op *op_p;
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int orig_log_level;
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@ -544,10 +545,6 @@ void __handle_sysrq(int key, struct tty_struct *tty, int check_mask)
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spin_unlock_irqrestore(&sysrq_key_table_lock, flags);
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}
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/*
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* This function is called by the keyboard handler when SysRq is pressed
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* and any other keycode arrives.
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*/
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void handle_sysrq(int key, struct tty_struct *tty)
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{
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if (sysrq_on())
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@ -555,10 +552,177 @@ void handle_sysrq(int key, struct tty_struct *tty)
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}
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EXPORT_SYMBOL(handle_sysrq);
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#ifdef CONFIG_INPUT
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/* Simple translation table for the SysRq keys */
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static const unsigned char sysrq_xlate[KEY_MAX + 1] =
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"\000\0331234567890-=\177\t" /* 0x00 - 0x0f */
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"qwertyuiop[]\r\000as" /* 0x10 - 0x1f */
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"dfghjkl;'`\000\\zxcv" /* 0x20 - 0x2f */
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"bnm,./\000*\000 \000\201\202\203\204\205" /* 0x30 - 0x3f */
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"\206\207\210\211\212\000\000789-456+1" /* 0x40 - 0x4f */
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"230\177\000\000\213\214\000\000\000\000\000\000\000\000\000\000" /* 0x50 - 0x5f */
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"\r\000/"; /* 0x60 - 0x6f */
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static bool sysrq_down;
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static int sysrq_alt_use;
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static int sysrq_alt;
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static bool sysrq_filter(struct input_handle *handle, unsigned int type,
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unsigned int code, int value)
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{
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if (type != EV_KEY)
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goto out;
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switch (code) {
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case KEY_LEFTALT:
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case KEY_RIGHTALT:
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if (value)
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sysrq_alt = code;
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else if (sysrq_down && code == sysrq_alt_use)
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sysrq_down = false;
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break;
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case KEY_SYSRQ:
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if (value == 1 && sysrq_alt) {
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sysrq_down = true;
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sysrq_alt_use = sysrq_alt;
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}
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break;
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default:
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if (sysrq_down && value && value != 2)
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__handle_sysrq(sysrq_xlate[code], NULL, 1);
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break;
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}
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out:
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return sysrq_down;
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}
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static int sysrq_connect(struct input_handler *handler,
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struct input_dev *dev,
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const struct input_device_id *id)
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{
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struct input_handle *handle;
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int error;
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sysrq_down = false;
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sysrq_alt = 0;
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handle = kzalloc(sizeof(struct input_handle), GFP_KERNEL);
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if (!handle)
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return -ENOMEM;
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handle->dev = dev;
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handle->handler = handler;
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handle->name = "sysrq";
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error = input_register_handle(handle);
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if (error) {
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pr_err("Failed to register input sysrq handler, error %d\n",
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error);
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goto err_free;
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}
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error = input_open_device(handle);
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if (error) {
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pr_err("Failed to open input device, error %d\n", error);
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goto err_unregister;
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}
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return 0;
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err_unregister:
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input_unregister_handle(handle);
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err_free:
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kfree(handle);
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return error;
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}
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static void sysrq_disconnect(struct input_handle *handle)
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{
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input_close_device(handle);
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input_unregister_handle(handle);
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kfree(handle);
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}
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/*
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* We are matching on KEY_LEFTALT insteard of KEY_SYSRQ because not all
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* keyboards have SysRq ikey predefined and so user may add it to keymap
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* later, but we expect all such keyboards to have left alt.
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*/
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static const struct input_device_id sysrq_ids[] = {
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{
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.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
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INPUT_DEVICE_ID_MATCH_KEYBIT,
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.evbit = { BIT_MASK(EV_KEY) },
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.keybit = { BIT_MASK(KEY_LEFTALT) },
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},
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{ },
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};
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static struct input_handler sysrq_handler = {
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.filter = sysrq_filter,
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.connect = sysrq_connect,
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.disconnect = sysrq_disconnect,
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.name = "sysrq",
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.id_table = sysrq_ids,
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};
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static bool sysrq_handler_registered;
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static inline void sysrq_register_handler(void)
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{
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int error;
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error = input_register_handler(&sysrq_handler);
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if (error)
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pr_err("Failed to register input handler, error %d", error);
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else
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sysrq_handler_registered = true;
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}
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static inline void sysrq_unregister_handler(void)
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{
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if (sysrq_handler_registered) {
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input_unregister_handler(&sysrq_handler);
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sysrq_handler_registered = false;
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}
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}
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#else
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static inline void sysrq_register_handler(void)
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{
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}
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static inline void sysrq_unregister_handler(void)
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{
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}
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#endif /* CONFIG_INPUT */
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int sysrq_toggle_support(int enable_mask)
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{
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bool was_enabled = sysrq_on();
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sysrq_enabled = enable_mask;
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if (was_enabled != sysrq_on()) {
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if (sysrq_on())
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sysrq_register_handler();
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else
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sysrq_unregister_handler();
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}
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return 0;
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}
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static int __sysrq_swap_key_ops(int key, struct sysrq_key_op *insert_op_p,
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struct sysrq_key_op *remove_op_p)
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{
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int retval;
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unsigned long flags;
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@ -599,6 +763,7 @@ static ssize_t write_sysrq_trigger(struct file *file, const char __user *buf,
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return -EFAULT;
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__handle_sysrq(c, NULL, 0);
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}
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return count;
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}
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@ -606,10 +771,28 @@ static const struct file_operations proc_sysrq_trigger_operations = {
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.write = write_sysrq_trigger,
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};
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static void sysrq_init_procfs(void)
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{
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if (!proc_create("sysrq-trigger", S_IWUSR, NULL,
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&proc_sysrq_trigger_operations))
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pr_err("Failed to register proc interface\n");
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}
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#else
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static inline void sysrq_init_procfs(void)
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{
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}
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#endif /* CONFIG_PROC_FS */
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static int __init sysrq_init(void)
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{
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proc_create("sysrq-trigger", S_IWUSR, NULL, &proc_sysrq_trigger_operations);
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sysrq_init_procfs();
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if (sysrq_on())
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sysrq_register_handler();
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return 0;
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}
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module_init(sysrq_init);
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#endif
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|
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|
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@ -39,40 +39,33 @@ struct sysrq_key_op {
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|
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#ifdef CONFIG_MAGIC_SYSRQ
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extern int sysrq_on(void);
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|
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/*
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* Do not use this one directly:
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*/
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extern int __sysrq_enabled;
|
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|
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/* Generic SysRq interface -- you may call it from any device driver, supplying
|
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* ASCII code of the key, pointer to registers and kbd/tty structs (if they
|
||||
* are available -- else NULL's).
|
||||
*/
|
||||
|
||||
void handle_sysrq(int key, struct tty_struct *tty);
|
||||
void __handle_sysrq(int key, struct tty_struct *tty, int check_mask);
|
||||
int register_sysrq_key(int key, struct sysrq_key_op *op);
|
||||
int unregister_sysrq_key(int key, struct sysrq_key_op *op);
|
||||
struct sysrq_key_op *__sysrq_get_key_op(int key);
|
||||
|
||||
int sysrq_toggle_support(int enable_mask);
|
||||
|
||||
#else
|
||||
|
||||
static inline int sysrq_on(void)
|
||||
{
|
||||
return 0;
|
||||
}
|
||||
static inline int __reterr(void)
|
||||
{
|
||||
return -EINVAL;
|
||||
}
|
||||
static inline void handle_sysrq(int key, struct tty_struct *tty)
|
||||
{
|
||||
}
|
||||
|
||||
#define register_sysrq_key(ig,nore) __reterr()
|
||||
#define unregister_sysrq_key(ig,nore) __reterr()
|
||||
static inline int register_sysrq_key(int key, struct sysrq_key_op *op)
|
||||
{
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
static inline int unregister_sysrq_key(int key, struct sysrq_key_op *op)
|
||||
{
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
#endif
|
||||
|
||||
|
|
|
|||
|
|
@ -163,6 +163,27 @@ static int proc_taint(struct ctl_table *table, int write,
|
|||
void __user *buffer, size_t *lenp, loff_t *ppos);
|
||||
#endif
|
||||
|
||||
#ifdef CONFIG_MAGIC_SYSRQ
|
||||
static int __sysrq_enabled; /* Note: sysrq code ises it's own private copy */
|
||||
|
||||
static int sysrq_sysctl_handler(ctl_table *table, int write,
|
||||
void __user *buffer, size_t *lenp,
|
||||
loff_t *ppos)
|
||||
{
|
||||
int error;
|
||||
|
||||
error = proc_dointvec(table, write, buffer, lenp, ppos);
|
||||
if (error)
|
||||
return error;
|
||||
|
||||
if (write)
|
||||
sysrq_toggle_support(__sysrq_enabled);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
#endif
|
||||
|
||||
static struct ctl_table root_table[];
|
||||
static struct ctl_table_root sysctl_table_root;
|
||||
static struct ctl_table_header root_table_header = {
|
||||
|
|
@ -567,7 +588,7 @@ static struct ctl_table kern_table[] = {
|
|||
.data = &__sysrq_enabled,
|
||||
.maxlen = sizeof (int),
|
||||
.mode = 0644,
|
||||
.proc_handler = proc_dointvec,
|
||||
.proc_handler = sysrq_sysctl_handler,
|
||||
},
|
||||
#endif
|
||||
#ifdef CONFIG_PROC_SYSCTL
|
||||
|
|
|
|||
Loading…
Reference in New Issue