You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
471 lines
11 KiB
471 lines
11 KiB
/* -*- 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>
|
|
* based on ideas by Pavel Machek <pavel@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
|
|
*/
|
|
|
|
#include <linux/config.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/tty.h>
|
|
#include <linux/mount.h>
|
|
#include <linux/kdev_t.h>
|
|
#include <linux/major.h>
|
|
#include <linux/reboot.h>
|
|
#include <linux/sysrq.h>
|
|
#include <linux/kbd_kern.h>
|
|
#include <linux/quotaops.h>
|
|
#include <linux/smp_lock.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/suspend.h>
|
|
#include <linux/writeback.h>
|
|
#include <linux/buffer_head.h> /* for fsync_bdev() */
|
|
#include <linux/swap.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/vt_kern.h>
|
|
#include <linux/workqueue.h>
|
|
#include <linux/kexec.h>
|
|
|
|
#include <asm/ptrace.h>
|
|
|
|
/* Whether we react on sysrq keys or just ignore them */
|
|
int sysrq_enabled = 1;
|
|
|
|
/* Loglevel sysrq handler */
|
|
static void sysrq_handle_loglevel(int key, struct pt_regs *pt_regs,
|
|
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",
|
|
.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)
|
|
{
|
|
if (tty)
|
|
do_SAK(tty);
|
|
reset_vc(vc_cons[fg_console].d);
|
|
}
|
|
static struct sysrq_key_op sysrq_SAK_op = {
|
|
.handler = sysrq_handle_SAK,
|
|
.help_msg = "saK",
|
|
.action_msg = "SAK",
|
|
.enable_mask = SYSRQ_ENABLE_KEYBOARD,
|
|
};
|
|
#endif
|
|
|
|
#ifdef CONFIG_VT
|
|
/* unraw sysrq handler */
|
|
static void sysrq_handle_unraw(int key, struct pt_regs *pt_regs,
|
|
struct tty_struct *tty)
|
|
{
|
|
struct kbd_struct *kbd = &kbd_table[fg_console];
|
|
|
|
if (kbd)
|
|
kbd->kbdmode = VC_XLATE;
|
|
}
|
|
static struct sysrq_key_op sysrq_unraw_op = {
|
|
.handler = sysrq_handle_unraw,
|
|
.help_msg = "unRaw",
|
|
.action_msg = "Keyboard mode set to XLATE",
|
|
.enable_mask = SYSRQ_ENABLE_KEYBOARD,
|
|
};
|
|
#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)
|
|
{
|
|
crash_kexec(pt_regs);
|
|
}
|
|
static struct sysrq_key_op sysrq_crashdump_op = {
|
|
.handler = sysrq_handle_crashdump,
|
|
.help_msg = "Crashdump",
|
|
.action_msg = "Trigger a crashdump",
|
|
.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)
|
|
{
|
|
local_irq_enable();
|
|
emergency_restart();
|
|
}
|
|
|
|
static struct sysrq_key_op sysrq_reboot_op = {
|
|
.handler = sysrq_handle_reboot,
|
|
.help_msg = "reBoot",
|
|
.action_msg = "Resetting",
|
|
.enable_mask = SYSRQ_ENABLE_BOOT,
|
|
};
|
|
|
|
static void sysrq_handle_sync(int key, struct pt_regs *pt_regs,
|
|
struct tty_struct *tty)
|
|
{
|
|
emergency_sync();
|
|
}
|
|
|
|
static struct sysrq_key_op sysrq_sync_op = {
|
|
.handler = sysrq_handle_sync,
|
|
.help_msg = "Sync",
|
|
.action_msg = "Emergency Sync",
|
|
.enable_mask = SYSRQ_ENABLE_SYNC,
|
|
};
|
|
|
|
static void sysrq_handle_mountro(int key, struct pt_regs *pt_regs,
|
|
struct tty_struct *tty)
|
|
{
|
|
emergency_remount();
|
|
}
|
|
|
|
static struct sysrq_key_op sysrq_mountro_op = {
|
|
.handler = sysrq_handle_mountro,
|
|
.help_msg = "Unmount",
|
|
.action_msg = "Emergency Remount R/O",
|
|
.enable_mask = SYSRQ_ENABLE_REMOUNT,
|
|
};
|
|
|
|
/* END SYNC SYSRQ HANDLERS BLOCK */
|
|
|
|
#ifdef CONFIG_DEBUG_MUTEXES
|
|
|
|
static void
|
|
sysrq_handle_showlocks(int key, struct pt_regs *pt_regs, struct tty_struct *tty)
|
|
{
|
|
mutex_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",
|
|
};
|
|
|
|
#endif
|
|
|
|
/* SHOW SYSRQ HANDLERS BLOCK */
|
|
|
|
static void sysrq_handle_showregs(int key, struct pt_regs *pt_regs,
|
|
struct tty_struct *tty)
|
|
{
|
|
if (pt_regs)
|
|
show_regs(pt_regs);
|
|
}
|
|
static struct sysrq_key_op sysrq_showregs_op = {
|
|
.handler = sysrq_handle_showregs,
|
|
.help_msg = "showPc",
|
|
.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)
|
|
{
|
|
show_state();
|
|
}
|
|
static struct sysrq_key_op sysrq_showstate_op = {
|
|
.handler = sysrq_handle_showstate,
|
|
.help_msg = "showTasks",
|
|
.action_msg = "Show State",
|
|
.enable_mask = SYSRQ_ENABLE_DUMP,
|
|
};
|
|
|
|
|
|
static void sysrq_handle_showmem(int key, struct pt_regs *pt_regs,
|
|
struct tty_struct *tty)
|
|
{
|
|
show_mem();
|
|
}
|
|
static struct sysrq_key_op sysrq_showmem_op = {
|
|
.handler = sysrq_handle_showmem,
|
|
.help_msg = "showMem",
|
|
.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 */
|
|
static void send_sig_all(int sig)
|
|
{
|
|
struct task_struct *p;
|
|
|
|
for_each_process(p) {
|
|
if (p->mm && p->pid != 1)
|
|
/* 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)
|
|
{
|
|
send_sig_all(SIGTERM);
|
|
console_loglevel = 8;
|
|
}
|
|
static struct sysrq_key_op sysrq_term_op = {
|
|
.handler = sysrq_handle_term,
|
|
.help_msg = "tErm",
|
|
.action_msg = "Terminate All Tasks",
|
|
.enable_mask = SYSRQ_ENABLE_SIGNAL,
|
|
};
|
|
|
|
static void moom_callback(void *ignored)
|
|
{
|
|
out_of_memory(GFP_KERNEL, 0);
|
|
}
|
|
|
|
static DECLARE_WORK(moom_work, moom_callback, NULL);
|
|
|
|
static void sysrq_handle_moom(int key, struct pt_regs *pt_regs,
|
|
struct tty_struct *tty)
|
|
{
|
|
schedule_work(&moom_work);
|
|
}
|
|
static struct sysrq_key_op sysrq_moom_op = {
|
|
.handler = sysrq_handle_moom,
|
|
.help_msg = "Full",
|
|
.action_msg = "Manual OOM execution",
|
|
};
|
|
|
|
static void sysrq_handle_kill(int key, struct pt_regs *pt_regs,
|
|
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",
|
|
.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)
|
|
{
|
|
normalize_rt_tasks();
|
|
}
|
|
static struct sysrq_key_op sysrq_unrt_op = {
|
|
.handler = sysrq_handle_unrt,
|
|
.help_msg = "Nice",
|
|
.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
|
|
#ifdef CONFIG_DEBUG_MUTEXES
|
|
/* d */ &sysrq_showlocks_op,
|
|
#else
|
|
/* d */ NULL,
|
|
#endif
|
|
/* 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,
|
|
#else
|
|
/* k */ NULL,
|
|
#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,
|
|
#else
|
|
/* r */ NULL,
|
|
#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
|
|
};
|
|
|
|
/* key2index calculation, -1 on invalid index */
|
|
static int sysrq_key_table_key2index(int key) {
|
|
int retval;
|
|
if ((key >= '0') && (key <= '9')) {
|
|
retval = key - '0';
|
|
} else if ((key >= 'a') && (key <= 'z')) {
|
|
retval = key + 10 - 'a';
|
|
} 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;
|
|
int i;
|
|
|
|
i = sysrq_key_table_key2index(key);
|
|
op_p = (i == -1) ? NULL : sysrq_key_table[i];
|
|
return op_p;
|
|
}
|
|
|
|
static void __sysrq_put_key_op (int key, struct sysrq_key_op *op_p) {
|
|
int i;
|
|
|
|
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)
|
|
{
|
|
struct sysrq_key_op *op_p;
|
|
int orig_log_level;
|
|
int i, j;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&sysrq_key_table_lock, flags);
|
|
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);
|
|
console_loglevel = orig_log_level;
|
|
op_p->handler(key, pt_regs, 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);
|
|
}
|
|
printk ("\n");
|
|
console_loglevel = orig_log_level;
|
|
}
|
|
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 pt_regs *pt_regs, struct tty_struct *tty)
|
|
{
|
|
if (!sysrq_enabled)
|
|
return;
|
|
__handle_sysrq(key, pt_regs, tty, 1);
|
|
}
|
|
|
|
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;
|
|
|
|
spin_lock_irqsave(&sysrq_key_table_lock, flags);
|
|
if (__sysrq_get_key_op(key) == remove_op_p) {
|
|
__sysrq_put_key_op(key, insert_op_p);
|
|
retval = 0;
|
|
} else {
|
|
retval = -1;
|
|
}
|
|
spin_unlock_irqrestore(&sysrq_key_table_lock, flags);
|
|
|
|
return retval;
|
|
}
|
|
|
|
int register_sysrq_key(int key, struct sysrq_key_op *op_p)
|
|
{
|
|
return __sysrq_swap_key_ops(key, op_p, NULL);
|
|
}
|
|
|
|
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);
|
|
|