-/* -*- 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 <mj@atrey.karlin.mff.cuni.cz>
* (c) 2000 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
* overhauled to use key registration
* based upon discusions in irc://irc.openprojects.net/#kernelnewbies
+ *
+ * Copyright (c) 2010 Dmitry Torokhov
+ * Input handler conversion
*/
-#include <linux/config.h>
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/mm.h>
#include <linux/reboot.h>
#include <linux/sysrq.h>
#include <linux/kbd_kern.h>
+#include <linux/proc_fs.h>
+#include <linux/nmi.h>
#include <linux/quotaops.h>
-#include <linux/smp_lock.h>
+#include <linux/perf_event.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/suspend.h>
#include <linux/spinlock.h>
#include <linux/vt_kern.h>
#include <linux/workqueue.h>
-#include <linux/kexec.h>
+#include <linux/hrtimer.h>
+#include <linux/oom.h>
+#include <linux/slab.h>
+#include <linux/input.h>
#include <asm/ptrace.h>
+#include <asm/irq_regs.h>
/* Whether we react on sysrq keys or just ignore them */
-int sysrq_enabled = 1;
+static int __read_mostly sysrq_enabled = 1;
+static bool __read_mostly sysrq_always_enabled;
+
+static bool sysrq_on(void)
+{
+ return sysrq_enabled || sysrq_always_enabled;
+}
+
+/*
+ * A value of 1 means 'all', other nonzero values are an op mask:
+ */
+static bool sysrq_on_mask(int mask)
+{
+ return sysrq_always_enabled ||
+ sysrq_enabled == 1 ||
+ (sysrq_enabled & mask);
+}
-/* Loglevel sysrq handler */
-static void sysrq_handle_loglevel(int key, struct pt_regs *pt_regs,
- struct tty_struct *tty)
+static int __init sysrq_always_enabled_setup(char *str)
+{
+ sysrq_always_enabled = true;
+ pr_info("sysrq always enabled.\n");
+
+ return 1;
+}
+
+__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);
console_loglevel = i;
-}
+}
static struct sysrq_key_op sysrq_loglevel_op = {
.handler = sysrq_handle_loglevel,
- .help_msg = "loglevel0-8",
+ .help_msg = "loglevel(0-9)",
.action_msg = "Changing Loglevel",
.enable_mask = SYSRQ_ENABLE_LOG,
};
-
-/* SAK sysrq handler */
#ifdef CONFIG_VT
-static void sysrq_handle_SAK(int key, struct pt_regs *pt_regs,
- struct tty_struct *tty)
+static void sysrq_handle_SAK(int key, struct tty_struct *tty)
{
- if (tty)
- do_SAK(tty);
- reset_vc(vc_cons[fg_console].d);
+ struct work_struct *SAK_work = &vc_cons[fg_console].SAK_work;
+ schedule_work(SAK_work);
}
static struct sysrq_key_op sysrq_SAK_op = {
.handler = sysrq_handle_SAK,
.action_msg = "SAK",
.enable_mask = SYSRQ_ENABLE_KEYBOARD,
};
+#else
+#define sysrq_SAK_op (*(struct sysrq_key_op *)NULL)
#endif
#ifdef CONFIG_VT
-/* unraw sysrq handler */
-static void sysrq_handle_unraw(int key, struct pt_regs *pt_regs,
- struct tty_struct *tty)
+static void sysrq_handle_unraw(int key, struct tty_struct *tty)
{
struct kbd_struct *kbd = &kbd_table[fg_console];
if (kbd)
- kbd->kbdmode = VC_XLATE;
+ kbd->kbdmode = default_utf8 ? VC_UNICODE : VC_XLATE;
}
static struct sysrq_key_op sysrq_unraw_op = {
.handler = sysrq_handle_unraw,
.help_msg = "unRaw",
- .action_msg = "Keyboard mode set to XLATE",
+ .action_msg = "Keyboard mode set to system default",
.enable_mask = SYSRQ_ENABLE_KEYBOARD,
};
+#else
+#define sysrq_unraw_op (*(struct sysrq_key_op *)NULL)
#endif /* CONFIG_VT */
-#ifdef CONFIG_KEXEC
-/* crashdump sysrq handler */
-static void sysrq_handle_crashdump(int key, struct pt_regs *pt_regs,
- struct tty_struct *tty)
+static void sysrq_handle_crash(int key, struct tty_struct *tty)
{
- crash_kexec(pt_regs);
+ char *killer = NULL;
+
+ panic_on_oops = 1; /* force panic */
+ wmb();
+ *killer = 1;
}
-static struct sysrq_key_op sysrq_crashdump_op = {
- .handler = sysrq_handle_crashdump,
- .help_msg = "Crashdump",
- .action_msg = "Trigger a crashdump",
+static struct sysrq_key_op sysrq_crash_op = {
+ .handler = sysrq_handle_crash,
+ .help_msg = "Crash",
+ .action_msg = "Trigger a crash",
.enable_mask = SYSRQ_ENABLE_DUMP,
};
-#endif
-/* reboot sysrq handler */
-static void sysrq_handle_reboot(int key, struct pt_regs *pt_regs,
- struct tty_struct *tty)
+static void sysrq_handle_reboot(int key, struct tty_struct *tty)
{
+ lockdep_off();
local_irq_enable();
emergency_restart();
}
-
static struct sysrq_key_op sysrq_reboot_op = {
.handler = sysrq_handle_reboot,
.help_msg = "reBoot",
.enable_mask = SYSRQ_ENABLE_BOOT,
};
-static void sysrq_handle_sync(int key, struct pt_regs *pt_regs,
- struct tty_struct *tty)
+static void sysrq_handle_sync(int key, struct tty_struct *tty)
{
emergency_sync();
}
-
static struct sysrq_key_op sysrq_sync_op = {
.handler = sysrq_handle_sync,
.help_msg = "Sync",
.enable_mask = SYSRQ_ENABLE_SYNC,
};
-static void sysrq_handle_mountro(int key, struct pt_regs *pt_regs,
- struct tty_struct *tty)
+static void sysrq_handle_show_timers(int key, struct tty_struct *tty)
{
- emergency_remount();
+ sysrq_timer_list_show();
}
+static struct sysrq_key_op sysrq_show_timers_op = {
+ .handler = sysrq_handle_show_timers,
+ .help_msg = "show-all-timers(Q)",
+ .action_msg = "Show clockevent devices & pending hrtimers (no others)",
+};
+
+static void sysrq_handle_mountro(int key, struct tty_struct *tty)
+{
+ emergency_remount();
+}
static struct sysrq_key_op sysrq_mountro_op = {
.handler = sysrq_handle_mountro,
.help_msg = "Unmount",
.enable_mask = SYSRQ_ENABLE_REMOUNT,
};
-/* END SYNC SYSRQ HANDLERS BLOCK */
+#ifdef CONFIG_LOCKDEP
+static void sysrq_handle_showlocks(int key, struct tty_struct *tty)
+{
+ debug_show_all_locks();
+}
+
+static struct sysrq_key_op sysrq_showlocks_op = {
+ .handler = sysrq_handle_showlocks,
+ .help_msg = "show-all-locks(D)",
+ .action_msg = "Show Locks Held",
+};
+#else
+#define sysrq_showlocks_op (*(struct sysrq_key_op *)NULL)
+#endif
+
+#ifdef CONFIG_SMP
+static DEFINE_SPINLOCK(show_lock);
+
+static void showacpu(void *dummy)
+{
+ unsigned long flags;
+ /* Idle CPUs have no interesting backtrace. */
+ if (idle_cpu(smp_processor_id()))
+ return;
-/* SHOW SYSRQ HANDLERS BLOCK */
+ spin_lock_irqsave(&show_lock, flags);
+ printk(KERN_INFO "CPU%d:\n", smp_processor_id());
+ show_stack(NULL, NULL);
+ spin_unlock_irqrestore(&show_lock, flags);
+}
-static void sysrq_handle_showregs(int key, struct pt_regs *pt_regs,
- struct tty_struct *tty)
+static void sysrq_showregs_othercpus(struct work_struct *dummy)
{
- if (pt_regs)
- show_regs(pt_regs);
+ smp_call_function(showacpu, NULL, 0);
+}
+
+static DECLARE_WORK(sysrq_showallcpus, sysrq_showregs_othercpus);
+
+static void sysrq_handle_showallcpus(int key, struct tty_struct *tty)
+{
+ /*
+ * Fall back to the workqueue based printing if the
+ * backtrace printing did not succeed or the
+ * architecture has no support for it:
+ */
+ if (!trigger_all_cpu_backtrace()) {
+ struct pt_regs *regs = get_irq_regs();
+
+ if (regs) {
+ printk(KERN_INFO "CPU%d:\n", smp_processor_id());
+ show_regs(regs);
+ }
+ schedule_work(&sysrq_showallcpus);
+ }
+}
+
+static struct sysrq_key_op sysrq_showallcpus_op = {
+ .handler = sysrq_handle_showallcpus,
+ .help_msg = "show-backtrace-all-active-cpus(L)",
+ .action_msg = "Show backtrace of all active CPUs",
+ .enable_mask = SYSRQ_ENABLE_DUMP,
+};
+#endif
+
+static void sysrq_handle_showregs(int key, struct tty_struct *tty)
+{
+ struct pt_regs *regs = get_irq_regs();
+ if (regs)
+ show_regs(regs);
+ perf_event_print_debug();
}
static struct sysrq_key_op sysrq_showregs_op = {
.handler = sysrq_handle_showregs,
- .help_msg = "showPc",
+ .help_msg = "show-registers(P)",
.action_msg = "Show Regs",
.enable_mask = SYSRQ_ENABLE_DUMP,
};
-
-static void sysrq_handle_showstate(int key, struct pt_regs *pt_regs,
- struct tty_struct *tty)
+static void sysrq_handle_showstate(int key, struct tty_struct *tty)
{
show_state();
}
static struct sysrq_key_op sysrq_showstate_op = {
.handler = sysrq_handle_showstate,
- .help_msg = "showTasks",
+ .help_msg = "show-task-states(T)",
.action_msg = "Show State",
.enable_mask = SYSRQ_ENABLE_DUMP,
};
+static void sysrq_handle_showstate_blocked(int key, struct tty_struct *tty)
+{
+ show_state_filter(TASK_UNINTERRUPTIBLE);
+}
+static struct sysrq_key_op sysrq_showstate_blocked_op = {
+ .handler = sysrq_handle_showstate_blocked,
+ .help_msg = "show-blocked-tasks(W)",
+ .action_msg = "Show Blocked State",
+ .enable_mask = SYSRQ_ENABLE_DUMP,
+};
+
+#ifdef CONFIG_TRACING
+#include <linux/ftrace.h>
+
+static void sysrq_ftrace_dump(int key, struct tty_struct *tty)
+{
+ ftrace_dump(DUMP_ALL);
+}
+static struct sysrq_key_op sysrq_ftrace_dump_op = {
+ .handler = sysrq_ftrace_dump,
+ .help_msg = "dump-ftrace-buffer(Z)",
+ .action_msg = "Dump ftrace buffer",
+ .enable_mask = SYSRQ_ENABLE_DUMP,
+};
+#else
+#define sysrq_ftrace_dump_op (*(struct sysrq_key_op *)NULL)
+#endif
-static void sysrq_handle_showmem(int key, struct pt_regs *pt_regs,
- struct tty_struct *tty)
+static void sysrq_handle_showmem(int key, struct tty_struct *tty)
{
show_mem();
}
static struct sysrq_key_op sysrq_showmem_op = {
.handler = sysrq_handle_showmem,
- .help_msg = "showMem",
+ .help_msg = "show-memory-usage(M)",
.action_msg = "Show Memory",
.enable_mask = SYSRQ_ENABLE_DUMP,
};
-/* SHOW SYSRQ HANDLERS BLOCK */
-
-
-/* SIGNAL SYSRQ HANDLERS BLOCK */
-
-/* signal sysrq helper function
- * Sends a signal to all user processes */
+/*
+ * Signal sysrq helper function. Sends a signal to all user processes.
+ */
static void send_sig_all(int sig)
{
struct task_struct *p;
for_each_process(p) {
- if (p->mm && p->pid != 1)
+ if (p->mm && !is_global_init(p))
/* Not swapper, init nor kernel thread */
force_sig(sig, p);
}
}
-static void sysrq_handle_term(int key, struct pt_regs *pt_regs,
- struct tty_struct *tty)
+static void sysrq_handle_term(int key, struct tty_struct *tty)
{
send_sig_all(SIGTERM);
console_loglevel = 8;
}
static struct sysrq_key_op sysrq_term_op = {
.handler = sysrq_handle_term,
- .help_msg = "tErm",
+ .help_msg = "terminate-all-tasks(E)",
.action_msg = "Terminate All Tasks",
.enable_mask = SYSRQ_ENABLE_SIGNAL,
};
-static void moom_callback(void *ignored)
+static void moom_callback(struct work_struct *ignored)
{
- out_of_memory(GFP_KERNEL, 0);
+ out_of_memory(node_zonelist(0, GFP_KERNEL), GFP_KERNEL, 0, NULL);
}
-static DECLARE_WORK(moom_work, moom_callback, NULL);
+static DECLARE_WORK(moom_work, moom_callback);
-static void sysrq_handle_moom(int key, struct pt_regs *pt_regs,
- struct tty_struct *tty)
+static void sysrq_handle_moom(int key, struct tty_struct *tty)
{
schedule_work(&moom_work);
}
static struct sysrq_key_op sysrq_moom_op = {
.handler = sysrq_handle_moom,
- .help_msg = "Full",
+ .help_msg = "memory-full-oom-kill(F)",
.action_msg = "Manual OOM execution",
+ .enable_mask = SYSRQ_ENABLE_SIGNAL,
+};
+
+#ifdef CONFIG_BLOCK
+static void sysrq_handle_thaw(int key, struct tty_struct *tty)
+{
+ emergency_thaw_all();
+}
+static struct sysrq_key_op sysrq_thaw_op = {
+ .handler = sysrq_handle_thaw,
+ .help_msg = "thaw-filesystems(J)",
+ .action_msg = "Emergency Thaw of all frozen filesystems",
+ .enable_mask = SYSRQ_ENABLE_SIGNAL,
};
+#endif
-static void sysrq_handle_kill(int key, struct pt_regs *pt_regs,
- struct tty_struct *tty)
+static void sysrq_handle_kill(int key, struct tty_struct *tty)
{
send_sig_all(SIGKILL);
console_loglevel = 8;
}
static struct sysrq_key_op sysrq_kill_op = {
.handler = sysrq_handle_kill,
- .help_msg = "kIll",
+ .help_msg = "kill-all-tasks(I)",
.action_msg = "Kill All Tasks",
.enable_mask = SYSRQ_ENABLE_SIGNAL,
};
-/* END SIGNAL SYSRQ HANDLERS BLOCK */
-
-static void sysrq_handle_unrt(int key, struct pt_regs *pt_regs,
- struct tty_struct *tty)
+static void sysrq_handle_unrt(int key, struct tty_struct *tty)
{
normalize_rt_tasks();
}
static struct sysrq_key_op sysrq_unrt_op = {
.handler = sysrq_handle_unrt,
- .help_msg = "Nice",
+ .help_msg = "nice-all-RT-tasks(N)",
.action_msg = "Nice All RT Tasks",
.enable_mask = SYSRQ_ENABLE_RTNICE,
};
/* Key Operations table and lock */
static DEFINE_SPINLOCK(sysrq_key_table_lock);
-#define SYSRQ_KEY_TABLE_LENGTH 36
-static struct sysrq_key_op *sysrq_key_table[SYSRQ_KEY_TABLE_LENGTH] = {
-/* 0 */ &sysrq_loglevel_op,
-/* 1 */ &sysrq_loglevel_op,
-/* 2 */ &sysrq_loglevel_op,
-/* 3 */ &sysrq_loglevel_op,
-/* 4 */ &sysrq_loglevel_op,
-/* 5 */ &sysrq_loglevel_op,
-/* 6 */ &sysrq_loglevel_op,
-/* 7 */ &sysrq_loglevel_op,
-/* 8 */ &sysrq_loglevel_op,
-/* 9 */ &sysrq_loglevel_op,
-/* a */ NULL, /* Don't use for system provided sysrqs,
- it is handled specially on the sparc
- and will never arrive */
-/* b */ &sysrq_reboot_op,
-#ifdef CONFIG_KEXEC
-/* c */ &sysrq_crashdump_op,
-#else
-/* c */ NULL,
-#endif
-/* d */ NULL,
-/* e */ &sysrq_term_op,
-/* f */ &sysrq_moom_op,
-/* g */ NULL,
-/* h */ NULL,
-/* i */ &sysrq_kill_op,
-/* j */ NULL,
-#ifdef CONFIG_VT
-/* k */ &sysrq_SAK_op,
+
+static struct sysrq_key_op *sysrq_key_table[36] = {
+ &sysrq_loglevel_op, /* 0 */
+ &sysrq_loglevel_op, /* 1 */
+ &sysrq_loglevel_op, /* 2 */
+ &sysrq_loglevel_op, /* 3 */
+ &sysrq_loglevel_op, /* 4 */
+ &sysrq_loglevel_op, /* 5 */
+ &sysrq_loglevel_op, /* 6 */
+ &sysrq_loglevel_op, /* 7 */
+ &sysrq_loglevel_op, /* 8 */
+ &sysrq_loglevel_op, /* 9 */
+
+ /*
+ * a: Don't use for system provided sysrqs, it is handled specially on
+ * sparc and will never arrive.
+ */
+ NULL, /* a */
+ &sysrq_reboot_op, /* b */
+ &sysrq_crash_op, /* c & ibm_emac driver debug */
+ &sysrq_showlocks_op, /* d */
+ &sysrq_term_op, /* e */
+ &sysrq_moom_op, /* f */
+ /* g: May be registered for the kernel debugger */
+ NULL, /* g */
+ NULL, /* h - reserved for help */
+ &sysrq_kill_op, /* i */
+#ifdef CONFIG_BLOCK
+ &sysrq_thaw_op, /* j */
#else
-/* k */ NULL,
+ NULL, /* j */
#endif
-/* l */ NULL,
-/* m */ &sysrq_showmem_op,
-/* n */ &sysrq_unrt_op,
-/* o */ NULL, /* This will often be registered
- as 'Off' at init time */
-/* p */ &sysrq_showregs_op,
-/* q */ NULL,
-#ifdef CONFIG_VT
-/* r */ &sysrq_unraw_op,
+ &sysrq_SAK_op, /* k */
+#ifdef CONFIG_SMP
+ &sysrq_showallcpus_op, /* l */
#else
-/* r */ NULL,
+ NULL, /* l */
#endif
-/* s */ &sysrq_sync_op,
-/* t */ &sysrq_showstate_op,
-/* u */ &sysrq_mountro_op,
-/* v */ NULL, /* May be assigned at init time by SMP VOYAGER */
-/* w */ NULL,
-/* x */ NULL,
-/* y */ NULL,
-/* z */ NULL
+ &sysrq_showmem_op, /* m */
+ &sysrq_unrt_op, /* n */
+ /* o: This will often be registered as 'Off' at init time */
+ NULL, /* o */
+ &sysrq_showregs_op, /* p */
+ &sysrq_show_timers_op, /* q */
+ &sysrq_unraw_op, /* r */
+ &sysrq_sync_op, /* s */
+ &sysrq_showstate_op, /* t */
+ &sysrq_mountro_op, /* u */
+ /* v: May be registered for frame buffer console restore */
+ NULL, /* v */
+ &sysrq_showstate_blocked_op, /* w */
+ /* x: May be registered on ppc/powerpc for xmon */
+ NULL, /* x */
+ /* y: May be registered on sparc64 for global register dump */
+ NULL, /* y */
+ &sysrq_ftrace_dump_op, /* z */
};
/* key2index calculation, -1 on invalid index */
-static int sysrq_key_table_key2index(int key) {
+static int sysrq_key_table_key2index(int key)
+{
int retval;
- if ((key >= '0') && (key <= '9')) {
+
+ if ((key >= '0') && (key <= '9'))
retval = key - '0';
- } else if ((key >= 'a') && (key <= 'z')) {
+ else if ((key >= 'a') && (key <= 'z'))
retval = key + 10 - 'a';
- } else {
+ else
retval = -1;
- }
return retval;
}
/*
* get and put functions for the table, exposed to modules.
*/
-
-struct sysrq_key_op *__sysrq_get_key_op (int key) {
- struct sysrq_key_op *op_p;
+struct sysrq_key_op *__sysrq_get_key_op(int key)
+{
+ struct sysrq_key_op *op_p = NULL;
int i;
-
+
i = sysrq_key_table_key2index(key);
- op_p = (i == -1) ? NULL : sysrq_key_table[i];
+ if (i != -1)
+ op_p = sysrq_key_table[i];
+
return op_p;
}
-void __sysrq_put_key_op (int key, struct sysrq_key_op *op_p) {
- int i;
+static void __sysrq_put_key_op(int key, struct sysrq_key_op *op_p)
+{
+ int i = sysrq_key_table_key2index(key);
- i = sysrq_key_table_key2index(key);
if (i != -1)
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 pt_regs *pt_regs, 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;
- int i, j;
+ int i;
unsigned long flags;
spin_lock_irqsave(&sysrq_key_table_lock, flags);
+ /*
+ * Raise the apparent loglevel to maximum so that the sysrq header
+ * is shown to provide the user with positive feedback. We do not
+ * simply emit this at KERN_EMERG as that would change message
+ * routing in the consumers of /proc/kmsg.
+ */
orig_log_level = console_loglevel;
console_loglevel = 7;
printk(KERN_INFO "SysRq : ");
op_p = __sysrq_get_key_op(key);
if (op_p) {
- /* Should we check for enabled operations (/proc/sysrq-trigger should not)
- * and is the invoked operation enabled? */
- if (!check_mask || sysrq_enabled == 1 ||
- (sysrq_enabled & op_p->enable_mask)) {
- printk ("%s\n", op_p->action_msg);
+ /*
+ * Should we check for enabled operations (/proc/sysrq-trigger
+ * should not) and is the invoked operation enabled?
+ */
+ if (!check_mask || sysrq_on_mask(op_p->enable_mask)) {
+ printk("%s\n", op_p->action_msg);
console_loglevel = orig_log_level;
- op_p->handler(key, pt_regs, tty);
- }
- else
+ op_p->handler(key, tty);
+ } else {
printk("This sysrq operation is disabled.\n");
+ }
} else {
printk("HELP : ");
/* Only print the help msg once per handler */
- for (i=0; i<SYSRQ_KEY_TABLE_LENGTH; i++)
- if (sysrq_key_table[i]) {
- for (j=0; sysrq_key_table[i] != sysrq_key_table[j]; j++);
- if (j == i)
- printk ("%s ", sysrq_key_table[i]->help_msg);
+ for (i = 0; i < ARRAY_SIZE(sysrq_key_table); i++) {
+ if (sysrq_key_table[i]) {
+ int j;
+
+ for (j = 0; sysrq_key_table[i] !=
+ sysrq_key_table[j]; j++)
+ ;
+ if (j != i)
+ continue;
+ printk("%s ", sysrq_key_table[i]->help_msg);
+ }
}
- printk ("\n");
+ printk("\n");
console_loglevel = orig_log_level;
}
spin_unlock_irqrestore(&sysrq_key_table_lock, flags);
}
+void handle_sysrq(int key, struct tty_struct *tty)
+{
+ if (sysrq_on())
+ __handle_sysrq(key, tty, 1);
+}
+EXPORT_SYMBOL(handle_sysrq);
+
+#ifdef CONFIG_INPUT
+
+/* 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)
+ __handle_sysrq(sysrq_xlate[code], NULL, 1);
+ break;
+ }
+
+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);
+}
+
/*
- * This function is called by the keyboard handler when SysRq is pressed
- * and any other keycode arrives.
+ * 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,
+};
+
+static bool sysrq_handler_registered;
-void handle_sysrq(int key, struct pt_regs *pt_regs, struct tty_struct *tty)
+static inline void sysrq_register_handler(void)
+{
+ int error;
+
+ error = input_register_handler(&sysrq_handler);
+ if (error)
+ pr_err("Failed to register input handler, error %d", error);
+ else
+ sysrq_handler_registered = true;
+}
+
+static inline void sysrq_unregister_handler(void)
+{
+ if (sysrq_handler_registered) {
+ input_unregister_handler(&sysrq_handler);
+ sysrq_handler_registered = false;
+ }
+}
+
+#else
+
+static inline void sysrq_register_handler(void)
+{
+}
+
+static inline void sysrq_unregister_handler(void)
{
- if (!sysrq_enabled)
- return;
- __handle_sysrq(key, pt_regs, tty, 1);
}
-int __sysrq_swap_key_ops(int key, struct sysrq_key_op *insert_op_p,
- struct sysrq_key_op *remove_op_p) {
+#endif /* CONFIG_INPUT */
+
+int sysrq_toggle_support(int enable_mask)
+{
+ bool was_enabled = sysrq_on();
+
+ sysrq_enabled = enable_mask;
+
+ if (was_enabled != sysrq_on()) {
+ if (sysrq_on())
+ sysrq_register_handler();
+ else
+ sysrq_unregister_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)
+{
int retval;
unsigned long flags;
retval = -1;
}
spin_unlock_irqrestore(&sysrq_key_table_lock, flags);
-
return retval;
}
{
return __sysrq_swap_key_ops(key, op_p, NULL);
}
+EXPORT_SYMBOL(register_sysrq_key);
int unregister_sysrq_key(int key, struct sysrq_key_op *op_p)
{
return __sysrq_swap_key_ops(key, NULL, op_p);
}
-
-EXPORT_SYMBOL(handle_sysrq);
-EXPORT_SYMBOL(register_sysrq_key);
EXPORT_SYMBOL(unregister_sysrq_key);
+
+#ifdef CONFIG_PROC_FS
+/*
+ * writing 'C' to /proc/sysrq-trigger is like sysrq-C
+ */
+static ssize_t write_sysrq_trigger(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ if (count) {
+ char c;
+
+ if (get_user(c, buf))
+ return -EFAULT;
+ __handle_sysrq(c, NULL, 0);
+ }
+
+ return count;
+}
+
+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 /* CONFIG_PROC_FS */
+
+static int __init sysrq_init(void)
+{
+ sysrq_init_procfs();
+
+ if (sysrq_on())
+ sysrq_register_handler();
+
+ return 0;
+}
+module_init(sysrq_init);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff