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path: root/drivers/char/sysrq.c
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Diffstat (limited to 'drivers/char/sysrq.c')
-rw-r--r--drivers/char/sysrq.c250
1 files changed, 115 insertions, 135 deletions
diff --git a/drivers/char/sysrq.c b/drivers/char/sysrq.c
index d58f8231885..35082dc12ea 100644
--- a/drivers/char/sysrq.c
+++ b/drivers/char/sysrq.c
@@ -42,16 +42,15 @@
/* 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)
+ 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",
@@ -59,11 +58,9 @@ static struct sysrq_key_op sysrq_loglevel_op = {
.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)
+ struct tty_struct *tty)
{
if (tty)
do_SAK(tty);
@@ -75,12 +72,13 @@ static struct sysrq_key_op sysrq_SAK_op = {
.action_msg = "SAK",
.enable_mask = SYSRQ_ENABLE_KEYBOARD,
};
+#else
+#define sysrq_SAK_op (*(struct sysrq_key_op *)0)
#endif
#ifdef CONFIG_VT
-/* unraw sysrq handler */
static void sysrq_handle_unraw(int key, struct pt_regs *pt_regs,
- struct tty_struct *tty)
+ struct tty_struct *tty)
{
struct kbd_struct *kbd = &kbd_table[fg_console];
@@ -93,10 +91,11 @@ static struct sysrq_key_op sysrq_unraw_op = {
.action_msg = "Keyboard mode set to XLATE",
.enable_mask = SYSRQ_ENABLE_KEYBOARD,
};
+#else
+#define sysrq_unraw_op (*(struct sysrq_key_op *)0)
#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)
{
@@ -108,16 +107,16 @@ static struct sysrq_key_op sysrq_crashdump_op = {
.action_msg = "Trigger a crashdump",
.enable_mask = SYSRQ_ENABLE_DUMP,
};
+#else
+#define sysrq_crashdump_op (*(struct sysrq_key_op *)0)
#endif
-/* reboot sysrq handler */
static void sysrq_handle_reboot(int key, struct pt_regs *pt_regs,
- struct tty_struct *tty)
+ struct tty_struct *tty)
{
local_irq_enable();
emergency_restart();
}
-
static struct sysrq_key_op sysrq_reboot_op = {
.handler = sysrq_handle_reboot,
.help_msg = "reBoot",
@@ -126,11 +125,10 @@ static struct sysrq_key_op sysrq_reboot_op = {
};
static void sysrq_handle_sync(int key, struct pt_regs *pt_regs,
- struct tty_struct *tty)
+ struct tty_struct *tty)
{
emergency_sync();
}
-
static struct sysrq_key_op sysrq_sync_op = {
.handler = sysrq_handle_sync,
.help_msg = "Sync",
@@ -139,11 +137,10 @@ static struct sysrq_key_op sysrq_sync_op = {
};
static void sysrq_handle_mountro(int key, struct pt_regs *pt_regs,
- struct tty_struct *tty)
+ struct tty_struct *tty)
{
emergency_remount();
}
-
static struct sysrq_key_op sysrq_mountro_op = {
.handler = sysrq_handle_mountro,
.help_msg = "Unmount",
@@ -151,28 +148,23 @@ static struct sysrq_key_op sysrq_mountro_op = {
.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)
+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",
};
-
+#else
+#define sysrq_showlocks_op (*(struct sysrq_key_op *)0)
#endif
-/* SHOW SYSRQ HANDLERS BLOCK */
-
static void sysrq_handle_showregs(int key, struct pt_regs *pt_regs,
- struct tty_struct *tty)
+ struct tty_struct *tty)
{
if (pt_regs)
show_regs(pt_regs);
@@ -184,9 +176,8 @@ static struct sysrq_key_op sysrq_showregs_op = {
.enable_mask = SYSRQ_ENABLE_DUMP,
};
-
static void sysrq_handle_showstate(int key, struct pt_regs *pt_regs,
- struct tty_struct *tty)
+ struct tty_struct *tty)
{
show_state();
}
@@ -197,9 +188,8 @@ static struct sysrq_key_op sysrq_showstate_op = {
.enable_mask = SYSRQ_ENABLE_DUMP,
};
-
static void sysrq_handle_showmem(int key, struct pt_regs *pt_regs,
- struct tty_struct *tty)
+ struct tty_struct *tty)
{
show_mem();
}
@@ -210,13 +200,9 @@ static struct sysrq_key_op sysrq_showmem_op = {
.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;
@@ -229,7 +215,7 @@ static void send_sig_all(int sig)
}
static void sysrq_handle_term(int key, struct pt_regs *pt_regs,
- struct tty_struct *tty)
+ struct tty_struct *tty)
{
send_sig_all(SIGTERM);
console_loglevel = 8;
@@ -243,7 +229,8 @@ static struct sysrq_key_op sysrq_term_op = {
static void moom_callback(void *ignored)
{
- out_of_memory(&NODE_DATA(0)->node_zonelists[ZONE_NORMAL], GFP_KERNEL, 0);
+ out_of_memory(&NODE_DATA(0)->node_zonelists[ZONE_NORMAL],
+ GFP_KERNEL, 0);
}
static DECLARE_WORK(moom_work, moom_callback, NULL);
@@ -260,7 +247,7 @@ static struct sysrq_key_op sysrq_moom_op = {
};
static void sysrq_handle_kill(int key, struct pt_regs *pt_regs,
- struct tty_struct *tty)
+ struct tty_struct *tty)
{
send_sig_all(SIGKILL);
console_loglevel = 8;
@@ -272,8 +259,6 @@ static struct sysrq_key_op sysrq_kill_op = {
.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)
{
@@ -288,110 +273,99 @@ static struct sysrq_key_op sysrq_unrt_op = {
/* 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
+
+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 */
+
+ /*
+ * Don't use for system provided sysrqs, it is handled specially on
+ * sparc and will never arrive
+ */
+ NULL, /* a */
+ &sysrq_reboot_op, /* b */
+ &sysrq_crashdump_op, /* c */
+ &sysrq_showlocks_op, /* d */
+ &sysrq_term_op, /* e */
+ &sysrq_moom_op, /* f */
+ NULL, /* g */
+ NULL, /* h */
+ &sysrq_kill_op, /* i */
+ NULL, /* j */
+ &sysrq_SAK_op, /* k */
+ NULL, /* l */
+ &sysrq_showmem_op, /* m */
+ &sysrq_unrt_op, /* n */
+ /* This will often be registered as 'Off' at init time */
+ NULL, /* o */
+ &sysrq_showregs_op, /* p */
+ NULL, /* q */
+ &sysrq_unraw_op, /* r */
+ &sysrq_sync_op, /* s */
+ &sysrq_showstate_op, /* t */
+ &sysrq_mountro_op, /* u */
+ /* May be assigned at init time by SMP VOYAGER */
+ NULL, /* v */
+ NULL, /* w */
+ NULL, /* x */
+ NULL, /* y */
+ NULL /* 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;
}
-static 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
+ * 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)
+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;
+ int i;
unsigned long flags;
spin_lock_irqsave(&sysrq_key_table_lock, flags);
@@ -401,26 +375,34 @@ void __handle_sysrq(int key, struct pt_regs *pt_regs, struct tty_struct *tty, in
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? */
+ /*
+ * 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);
+ printk("%s\n", op_p->action_msg);
console_loglevel = orig_log_level;
op_p->handler(key, pt_regs, tty);
- }
- else
+ } 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);
@@ -430,16 +412,17 @@ void __handle_sysrq(int key, struct pt_regs *pt_regs, struct tty_struct *tty, in
* 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);
}
+EXPORT_SYMBOL(handle_sysrq);
static int __sysrq_swap_key_ops(int key, struct sysrq_key_op *insert_op_p,
- struct sysrq_key_op *remove_op_p) {
+ struct sysrq_key_op *remove_op_p)
+{
int retval;
unsigned long flags;
@@ -452,7 +435,6 @@ static int __sysrq_swap_key_ops(int key, struct sysrq_key_op *insert_op_p,
retval = -1;
}
spin_unlock_irqrestore(&sysrq_key_table_lock, flags);
-
return retval;
}
@@ -460,12 +442,10 @@ int register_sysrq_key(int key, struct sysrq_key_op *op_p)
{
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);