From patchwork Wed Mar 17 06:19:52 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Torokhov X-Patchwork-Id: 86266 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter.kernel.org (8.14.3/8.14.3) with ESMTP id o2H6K5Pv014233 for ; Wed, 17 Mar 2010 06:20:05 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753150Ab0CQGUE (ORCPT ); Wed, 17 Mar 2010 02:20:04 -0400 Received: from mail-gy0-f174.google.com ([209.85.160.174]:33656 "EHLO mail-gy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751915Ab0CQGUB (ORCPT ); Wed, 17 Mar 2010 02:20:01 -0400 Received: by gyg8 with SMTP id 8so345001gyg.19 for ; Tue, 16 Mar 2010 23:20:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:date:from:to:cc:subject :message-id:mime-version:content-type:content-disposition:user-agent; bh=bwlxE/FwH9Lt5FQttx+74Oj94P2mdjcZ+JvdaIC/Ciw=; b=blFE/we4cgD6TeYB+cRGcvdOtw6y9sCXt2pdapHeiJlNK3MKc/QqXueHyrhRGfRdMh xR2X0x+U2u3fybMYsoB6bHXdO0u1kN1R4aq4FS4fvSRLze0mEDIKq76JSY8nre7xiwnu 7AEN7kq7NIyBJa940mwxB6D0PdQG7nyhh+SeA= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:mime-version:content-type :content-disposition:user-agent; b=BXq3zjIJnpLAu7GP1bjhHOcLJwn1VN4wuSkYPVKQwXbRjzgLhbnDxx1aFiWPRyY33Y HFBgduyuDJ3vbPZy8LbAmbFOZ8pPsR/HFzCSwxnMkobZgM7l4KAb/4i9r3fbQBf+qbUp OFL6/8L8KoSfr6Dto8KeQiID5ACuwLGkCeNnk= Received: by 10.101.191.4 with SMTP id t4mr117925anp.232.1268806798966; Tue, 16 Mar 2010 23:19:58 -0700 (PDT) Received: from mailhub.coreip.homeip.net (c-24-6-153-206.hsd1.ca.comcast.net [24.6.153.206]) by mx.google.com with ESMTPS id 8sm2038961yxg.42.2010.03.16.23.19.55 (version=TLSv1/SSLv3 cipher=RC4-MD5); Tue, 16 Mar 2010 23:19:57 -0700 (PDT) Date: Tue, 16 Mar 2010 23:19:52 -0700 From: Dmitry Torokhov To: Linux Input Cc: LKML , Jason Wessel Subject: [RFC] Input: implement sysrq as an input handler Message-ID: <20100317061952.GA19789@core.coreip.homeip.net> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.20 (2009-08-17) Sender: linux-input-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.3 (demeter.kernel.org [140.211.167.41]); Wed, 17 Mar 2010 06:20:05 +0000 (UTC) diff --git a/drivers/char/keyboard.c b/drivers/char/keyboard.c index ada25bb..50f6c01 100644 --- a/drivers/char/keyboard.c +++ b/drivers/char/keyboard.c @@ -38,7 +38,6 @@ #include #include #include -#include #include #include #include @@ -82,8 +81,7 @@ void compute_shiftstate(void); typedef void (k_handler_fn)(struct vc_data *vc, unsigned char value, char up_flag); static k_handler_fn K_HANDLERS; -k_handler_fn *k_handler[16] = { K_HANDLERS }; -EXPORT_SYMBOL_GPL(k_handler); +static k_handler_fn *k_handler[16] = { K_HANDLERS }; #define FN_HANDLERS\ fn_null, fn_enter, fn_show_ptregs, fn_show_mem,\ @@ -147,22 +145,6 @@ static struct ledptr { unsigned char valid:1; } ledptrs[3]; -/* Simple translation table for the SysRq keys */ - -#ifdef CONFIG_MAGIC_SYSRQ -unsigned char kbd_sysrq_xlate[KEY_MAX + 1] = - "\000\0331234567890-=\177\t" /* 0x00 - 0x0f */ - "qwertyuiop[]\r\000as" /* 0x10 - 0x1f */ - "dfghjkl;'`\000\\zxcv" /* 0x20 - 0x2f */ - "bnm,./\000*\000 \000\201\202\203\204\205" /* 0x30 - 0x3f */ - "\206\207\210\211\212\000\000789-456+1" /* 0x40 - 0x4f */ - "230\177\000\000\213\214\000\000\000\000\000\000\000\000\000\000" /* 0x50 - 0x5f */ - "\r\000/"; /* 0x60 - 0x6f */ -static int sysrq_down; -static int sysrq_alt_use; -#endif -static int sysrq_alt; - /* * Notifier list for console keyboard events */ @@ -1108,7 +1090,8 @@ static int emulate_raw(struct vc_data *vc, unsigned int keycode, * pressing PrtSc/SysRq alone, but simply 0x54 * when pressing Alt+PrtSc/SysRq. */ - if (sysrq_alt) { + if (test_bit(KEY_LEFTALT, key_down) || + test_bit(KEY_RIGHTALT, key_down)) { put_queue(vc, 0x54 | up_flag); } else { put_queue(vc, 0xe0); @@ -1176,8 +1159,6 @@ static void kbd_keycode(unsigned int keycode, int down, int hw_raw) kbd = kbd_table + vc->vc_num; - if (keycode == KEY_LEFTALT || keycode == KEY_RIGHTALT) - sysrq_alt = down ? keycode : 0; #ifdef CONFIG_SPARC if (keycode == KEY_STOP) sparc_l1_a_state = down; @@ -1190,21 +1171,6 @@ static void kbd_keycode(unsigned int keycode, int down, int hw_raw) if (keycode < BTN_MISC && printk_ratelimit()) printk(KERN_WARNING "keyboard.c: can't emulate rawmode for keycode %d\n", keycode); -#ifdef CONFIG_MAGIC_SYSRQ /* Handle the SysRq Hack */ - if (keycode == KEY_SYSRQ && (sysrq_down || (down == 1 && sysrq_alt))) { - if (!sysrq_down) { - sysrq_down = down; - sysrq_alt_use = sysrq_alt; - } - return; - } - if (sysrq_down && !down && keycode == sysrq_alt_use) - sysrq_down = 0; - if (sysrq_down && down && !rep) { - handle_sysrq(kbd_sysrq_xlate[keycode], tty); - return; - } -#endif #ifdef CONFIG_SPARC if (keycode == KEY_A && sparc_l1_a_state) { sparc_l1_a_state = 0; diff --git a/drivers/char/sysrq.c b/drivers/char/sysrq.c index 1ae2de7..1883dd8 100644 --- a/drivers/char/sysrq.c +++ b/drivers/char/sysrq.c @@ -1,7 +1,4 @@ -/* -*- linux-c -*- - * - * $Id: sysrq.c,v 1.15 1998/08/23 14:56:41 mj Exp $ - * +/* * Linux Magic System Request Key Hacks * * (c) 1997 Martin Mares @@ -10,8 +7,13 @@ * (c) 2000 Crutcher Dunnavant * overhauled to use key registration * based upon discusions in irc://irc.openprojects.net/#kernelnewbies + * + * Copyright (c) 2010 Dmitry Torokhov + * Input handler conversion */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + #include #include #include @@ -38,33 +40,34 @@ #include #include #include +#include #include #include /* Whether we react on sysrq keys or just ignore them */ -int __read_mostly __sysrq_enabled = 1; +static int __read_mostly sysrq_enabled = 1; +static bool __read_mostly sysrq_always_enabled; -static int __read_mostly sysrq_always_enabled; - -int sysrq_on(void) +static bool sysrq_on(void) { - return __sysrq_enabled || sysrq_always_enabled; + return sysrq_enabled || sysrq_always_enabled; } /* * A value of 1 means 'all', other nonzero values are an op mask: */ -static inline int sysrq_on_mask(int mask) +static bool sysrq_on_mask(int mask) { - return sysrq_always_enabled || __sysrq_enabled == 1 || - (__sysrq_enabled & mask); + return sysrq_always_enabled || + sysrq_enabled == 1 || + (sysrq_enabled & mask); } static int __init sysrq_always_enabled_setup(char *str) { - sysrq_always_enabled = 1; - printk(KERN_INFO "debug: sysrq always enabled.\n"); + sysrq_always_enabled = true; + pr_info("sysrq always enabled.\n"); return 1; } @@ -75,6 +78,7 @@ __setup("sysrq_always_enabled", sysrq_always_enabled_setup); static void sysrq_handle_loglevel(int key, struct tty_struct *tty) { int i; + i = key - '0'; console_loglevel = 7; printk("Loglevel set to %d\n", i); @@ -100,7 +104,7 @@ static struct sysrq_key_op sysrq_SAK_op = { .enable_mask = SYSRQ_ENABLE_KEYBOARD, }; #else -#define sysrq_SAK_op (*(struct sysrq_key_op *)0) +#define sysrq_SAK_op (*(struct sysrq_key_op *)NULL) #endif #ifdef CONFIG_VT @@ -118,7 +122,7 @@ static struct sysrq_key_op sysrq_unraw_op = { .enable_mask = SYSRQ_ENABLE_KEYBOARD, }; #else -#define sysrq_unraw_op (*(struct sysrq_key_op *)0) +#define sysrq_unraw_op (*(struct sysrq_key_op *)NULL) #endif /* CONFIG_VT */ static void sysrq_handle_crash(int key, struct tty_struct *tty) @@ -194,7 +198,7 @@ static struct sysrq_key_op sysrq_showlocks_op = { .action_msg = "Show Locks Held", }; #else -#define sysrq_showlocks_op (*(struct sysrq_key_op *)0) +#define sysrq_showlocks_op (*(struct sysrq_key_op *)NULL) #endif #ifdef CONFIG_SMP @@ -297,7 +301,7 @@ static struct sysrq_key_op sysrq_ftrace_dump_op = { .enable_mask = SYSRQ_ENABLE_DUMP, }; #else -#define sysrq_ftrace_dump_op (*(struct sysrq_key_op *)0) +#define sysrq_ftrace_dump_op (*(struct sysrq_key_op *)NULL) #endif static void sysrq_handle_showmem(int key, struct tty_struct *tty) @@ -476,6 +480,7 @@ struct sysrq_key_op *__sysrq_get_key_op(int key) i = sysrq_key_table_key2index(key); if (i != -1) op_p = sysrq_key_table[i]; + return op_p; } @@ -487,11 +492,7 @@ static void __sysrq_put_key_op(int key, struct sysrq_key_op *op_p) sysrq_key_table[i] = op_p; } -/* - * This is the non-locking version of handle_sysrq. It must/can only be called - * by sysrq key handlers, as they are inside of the lock - */ -void __handle_sysrq(int key, struct tty_struct *tty, int check_mask) +static void __handle_sysrq(int key, struct tty_struct *tty, int check_mask) { struct sysrq_key_op *op_p; int orig_log_level; @@ -543,10 +544,6 @@ void __handle_sysrq(int key, struct tty_struct *tty, int check_mask) spin_unlock_irqrestore(&sysrq_key_table_lock, flags); } -/* - * This function is called by the keyboard handler when SysRq is pressed - * and any other keycode arrives. - */ void handle_sysrq(int key, struct tty_struct *tty) { if (sysrq_on()) @@ -554,6 +551,148 @@ void handle_sysrq(int key, struct tty_struct *tty) } EXPORT_SYMBOL(handle_sysrq); +/* Simple translation table for the SysRq keys */ +static const unsigned char sysrq_xlate[KEY_MAX + 1] = + "\000\0331234567890-=\177\t" /* 0x00 - 0x0f */ + "qwertyuiop[]\r\000as" /* 0x10 - 0x1f */ + "dfghjkl;'`\000\\zxcv" /* 0x20 - 0x2f */ + "bnm,./\000*\000 \000\201\202\203\204\205" /* 0x30 - 0x3f */ + "\206\207\210\211\212\000\000789-456+1" /* 0x40 - 0x4f */ + "230\177\000\000\213\214\000\000\000\000\000\000\000\000\000\000" /* 0x50 - 0x5f */ + "\r\000/"; /* 0x60 - 0x6f */ + +static bool sysrq_down; +static int sysrq_alt_use; +static int sysrq_alt; + +static bool sysrq_filter(struct input_handle *handle, unsigned int type, + unsigned int code, int value) +{ + + if (type != EV_KEY) + goto out; + + switch (code) { + + case KEY_LEFTALT: + case KEY_RIGHTALT: + if (value) + sysrq_alt = code; + else if (sysrq_down && code == sysrq_alt_use) + sysrq_down = false; + break; + + case KEY_SYSRQ: + if (value == 1 && sysrq_alt) { + sysrq_down = true; + sysrq_alt_use = sysrq_alt; + } + + break; + + default: + if (sysrq_down && value && value != 2) { + struct vc_data *vc = vc_cons[fg_console].d; + + __handle_sysrq(sysrq_xlate[code], vc->vc_tty, 1); + } + } + +out: + return sysrq_down; +} + +static int sysrq_connect(struct input_handler *handler, + struct input_dev *dev, + const struct input_device_id *id) +{ + struct input_handle *handle; + int error; + + sysrq_down = false; + sysrq_alt = 0; + + handle = kzalloc(sizeof(struct input_handle), GFP_KERNEL); + if (!handle) + return -ENOMEM; + + handle->dev = dev; + handle->handler = handler; + handle->name = "sysrq"; + + error = input_register_handle(handle); + if (error) { + pr_err("Failed to register input sysrq handler, error %d\n", + error); + goto err_free; + } + + error = input_open_device(handle); + if (error) { + pr_err("Failed to open input device, error %d\n", error); + goto err_unregister; + } + + return 0; + + err_unregister: + input_unregister_handle(handle); + err_free: + kfree(handle); + return error; +} + +static void sysrq_disconnect(struct input_handle *handle) +{ + input_close_device(handle); + input_unregister_handle(handle); + kfree(handle); +} + +/* + * We are matching on KEY_LEFTALT insteard of KEY_SYSRQ because not all + * keyboards have SysRq ikey predefined and so user may add it to keymap + * later, but we expect all such keyboards to have left alt. + */ +static const struct input_device_id sysrq_ids[] = { + { + .flags = INPUT_DEVICE_ID_MATCH_EVBIT | + INPUT_DEVICE_ID_MATCH_KEYBIT, + .evbit = { BIT_MASK(EV_KEY) }, + .keybit = { BIT_MASK(KEY_LEFTALT) }, + }, + { }, +}; + +static struct input_handler sysrq_handler = { + .filter = sysrq_filter, + .connect = sysrq_connect, + .disconnect = sysrq_disconnect, + .name = "sysrq", + .id_table = sysrq_ids, +}; + +int sysrq_toggle_support(int enable_mask) +{ + bool was_enabled = sysrq_on(); + int error; + + sysrq_enabled = enable_mask; + + if (was_enabled != sysrq_on()) { + if (sysrq_on()) { + error = input_register_handler(&sysrq_handler); + if (error) + pr_err("Failed to register input handler, error %d", + error); + + } else + input_unregister_handler(&sysrq_handler); + } + + return 0; +} + static int __sysrq_swap_key_ops(int key, struct sysrq_key_op *insert_op_p, struct sysrq_key_op *remove_op_p) { @@ -598,6 +737,7 @@ static ssize_t write_sysrq_trigger(struct file *file, const char __user *buf, return -EFAULT; __handle_sysrq(c, NULL, 0); } + return count; } @@ -605,10 +745,34 @@ static const struct file_operations proc_sysrq_trigger_operations = { .write = write_sysrq_trigger, }; +static void sysrq_init_procfs(void) +{ + if (!proc_create("sysrq-trigger", S_IWUSR, NULL, + &proc_sysrq_trigger_operations)) + pr_err("Failed to register proc interface\n"); +} + +#else + +static inline void sysrq_init_procfs(void) +{ +} + +#endif + static int __init sysrq_init(void) { - proc_create("sysrq-trigger", S_IWUSR, NULL, &proc_sysrq_trigger_operations); + int error; + + sysrq_init_procfs(); + + if (sysrq_on()) { + error = input_register_handler(&sysrq_handler); + if (error) + pr_err("Failed to register input handler, error %d", + error); + } + return 0; } module_init(sysrq_init); -#endif diff --git a/include/linux/sysrq.h b/include/linux/sysrq.h index 99adcdc..5f2bdef 100644 --- a/include/linux/sysrq.h +++ b/include/linux/sysrq.h @@ -39,41 +39,30 @@ struct sysrq_key_op { #ifdef CONFIG_MAGIC_SYSRQ -extern int sysrq_on(void); - -/* - * Do not use this one directly: - */ -extern int __sysrq_enabled; - /* Generic SysRq interface -- you may call it from any device driver, supplying * 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) +static inline int register_sysrq_key(int key, struct sysrq_key_op *op) { return -EINVAL; } -static inline void handle_sysrq(int key, struct tty_struct *tty) + +static inline int unregister_sysrq_key(int key, struct sysrq_key_op *op) { + return -EINVAL; } -#define register_sysrq_key(ig,nore) __reterr() -#define unregister_sysrq_key(ig,nore) __reterr() - #endif #endif /* _LINUX_SYSRQ_H */ diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 8686b0f..ce724a0 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -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