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Commit bf36b901 authored by Andrew Morton's avatar Andrew Morton Committed by Linus Torvalds
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[PATCH] sysrq cleanup 

sysrq.c is fairly revolting.  Fix.
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 21e4f952
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Showing with 115 additions and 135 deletions
drivers/char/sysrq.c
View file @ bf36b901
...@@ -42,16 +42,15 @@ ...@@ -42,16 +42,15 @@
/* Whether we react on sysrq keys or just ignore them */ /* Whether we react on sysrq keys or just ignore them */
int sysrq_enabled = 1; int sysrq_enabled = 1;
/* Loglevel sysrq handler */
static void sysrq_handle_loglevel(int key, struct pt_regs *pt_regs, static void sysrq_handle_loglevel(int key, struct pt_regs *pt_regs,
struct tty_struct *tty) struct tty_struct *tty)
{ {
int i; int i;
i = key - '0'; i = key - '0';
console_loglevel = 7; console_loglevel = 7;
printk("Loglevel set to %d\n", i); printk("Loglevel set to %d\n", i);
console_loglevel = i; console_loglevel = i;
} }
static struct sysrq_key_op sysrq_loglevel_op = { static struct sysrq_key_op sysrq_loglevel_op = {
.handler = sysrq_handle_loglevel, .handler = sysrq_handle_loglevel,
.help_msg = "loglevel0-8", .help_msg = "loglevel0-8",
...@@ -59,11 +58,9 @@ static struct sysrq_key_op sysrq_loglevel_op = { ...@@ -59,11 +58,9 @@ static struct sysrq_key_op sysrq_loglevel_op = {
.enable_mask = SYSRQ_ENABLE_LOG, .enable_mask = SYSRQ_ENABLE_LOG,
}; };
/* SAK sysrq handler */
#ifdef CONFIG_VT #ifdef CONFIG_VT
static void sysrq_handle_SAK(int key, struct pt_regs *pt_regs, static void sysrq_handle_SAK(int key, struct pt_regs *pt_regs,
struct tty_struct *tty) struct tty_struct *tty)
{ {
if (tty) if (tty)
do_SAK(tty); do_SAK(tty);
...@@ -75,12 +72,13 @@ static struct sysrq_key_op sysrq_SAK_op = { ...@@ -75,12 +72,13 @@ static struct sysrq_key_op sysrq_SAK_op = {
.action_msg = "SAK", .action_msg = "SAK",
.enable_mask = SYSRQ_ENABLE_KEYBOARD, .enable_mask = SYSRQ_ENABLE_KEYBOARD,
}; };
#else
#define sysrq_SAK_op (*(struct sysrq_key_op *)0)
#endif #endif
#ifdef CONFIG_VT #ifdef CONFIG_VT
/* unraw sysrq handler */
static void sysrq_handle_unraw(int key, struct pt_regs *pt_regs, 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]; struct kbd_struct *kbd = &kbd_table[fg_console];
...@@ -93,10 +91,11 @@ static struct sysrq_key_op sysrq_unraw_op = { ...@@ -93,10 +91,11 @@ static struct sysrq_key_op sysrq_unraw_op = {
.action_msg = "Keyboard mode set to XLATE", .action_msg = "Keyboard mode set to XLATE",
.enable_mask = SYSRQ_ENABLE_KEYBOARD, .enable_mask = SYSRQ_ENABLE_KEYBOARD,
}; };
#else
#define sysrq_unraw_op (*(struct sysrq_key_op *)0)
#endif /* CONFIG_VT */ #endif /* CONFIG_VT */
#ifdef CONFIG_KEXEC #ifdef CONFIG_KEXEC
/* crashdump sysrq handler */
static void sysrq_handle_crashdump(int key, struct pt_regs *pt_regs, static void sysrq_handle_crashdump(int key, struct pt_regs *pt_regs,
struct tty_struct *tty) struct tty_struct *tty)
{ {
...@@ -108,16 +107,16 @@ static struct sysrq_key_op sysrq_crashdump_op = { ...@@ -108,16 +107,16 @@ static struct sysrq_key_op sysrq_crashdump_op = {
.action_msg = "Trigger a crashdump", .action_msg = "Trigger a crashdump",
.enable_mask = SYSRQ_ENABLE_DUMP, .enable_mask = SYSRQ_ENABLE_DUMP,
}; };
#else
#define sysrq_crashdump_op (*(struct sysrq_key_op *)0)
#endif #endif
/* reboot sysrq handler */
static void sysrq_handle_reboot(int key, struct pt_regs *pt_regs, static void sysrq_handle_reboot(int key, struct pt_regs *pt_regs,
struct tty_struct *tty) struct tty_struct *tty)
{ {
local_irq_enable(); local_irq_enable();
emergency_restart(); emergency_restart();
} }
static struct sysrq_key_op sysrq_reboot_op = { static struct sysrq_key_op sysrq_reboot_op = {
.handler = sysrq_handle_reboot, .handler = sysrq_handle_reboot,
.help_msg = "reBoot", .help_msg = "reBoot",
...@@ -126,11 +125,10 @@ static struct sysrq_key_op sysrq_reboot_op = { ...@@ -126,11 +125,10 @@ static struct sysrq_key_op sysrq_reboot_op = {
}; };
static void sysrq_handle_sync(int key, struct pt_regs *pt_regs, static void sysrq_handle_sync(int key, struct pt_regs *pt_regs,
struct tty_struct *tty) struct tty_struct *tty)
{ {
emergency_sync(); emergency_sync();
} }
static struct sysrq_key_op sysrq_sync_op = { static struct sysrq_key_op sysrq_sync_op = {
.handler = sysrq_handle_sync, .handler = sysrq_handle_sync,
.help_msg = "Sync", .help_msg = "Sync",
...@@ -139,11 +137,10 @@ static struct sysrq_key_op sysrq_sync_op = { ...@@ -139,11 +137,10 @@ static struct sysrq_key_op sysrq_sync_op = {
}; };
static void sysrq_handle_mountro(int key, struct pt_regs *pt_regs, static void sysrq_handle_mountro(int key, struct pt_regs *pt_regs,
struct tty_struct *tty) struct tty_struct *tty)
{ {
emergency_remount(); emergency_remount();
} }
static struct sysrq_key_op sysrq_mountro_op = { static struct sysrq_key_op sysrq_mountro_op = {
.handler = sysrq_handle_mountro, .handler = sysrq_handle_mountro,
.help_msg = "Unmount", .help_msg = "Unmount",
...@@ -151,28 +148,23 @@ static struct sysrq_key_op sysrq_mountro_op = { ...@@ -151,28 +148,23 @@ static struct sysrq_key_op sysrq_mountro_op = {
.enable_mask = SYSRQ_ENABLE_REMOUNT, .enable_mask = SYSRQ_ENABLE_REMOUNT,
}; };
/* END SYNC SYSRQ HANDLERS BLOCK */
#ifdef CONFIG_DEBUG_MUTEXES #ifdef CONFIG_DEBUG_MUTEXES
static void sysrq_handle_showlocks(int key, struct pt_regs *pt_regs,
static void struct tty_struct *tty)
sysrq_handle_showlocks(int key, struct pt_regs *pt_regs, struct tty_struct *tty)
{ {
mutex_debug_show_all_locks(); mutex_debug_show_all_locks();
} }
static struct sysrq_key_op sysrq_showlocks_op = { static struct sysrq_key_op sysrq_showlocks_op = {
.handler = sysrq_handle_showlocks, .handler = sysrq_handle_showlocks,
.help_msg = "show-all-locks(D)", .help_msg = "show-all-locks(D)",
.action_msg = "Show Locks Held", .action_msg = "Show Locks Held",
}; };
#else
#define sysrq_showlocks_op (*(struct sysrq_key_op *)0)
#endif #endif
/* SHOW SYSRQ HANDLERS BLOCK */
static void sysrq_handle_showregs(int key, struct pt_regs *pt_regs, static void sysrq_handle_showregs(int key, struct pt_regs *pt_regs,
struct tty_struct *tty) struct tty_struct *tty)
{ {
if (pt_regs) if (pt_regs)
show_regs(pt_regs); show_regs(pt_regs);
...@@ -184,9 +176,8 @@ static struct sysrq_key_op sysrq_showregs_op = { ...@@ -184,9 +176,8 @@ static struct sysrq_key_op sysrq_showregs_op = {
.enable_mask = SYSRQ_ENABLE_DUMP, .enable_mask = SYSRQ_ENABLE_DUMP,
}; };
static void sysrq_handle_showstate(int key, struct pt_regs *pt_regs, static void sysrq_handle_showstate(int key, struct pt_regs *pt_regs,
struct tty_struct *tty) struct tty_struct *tty)
{ {
show_state(); show_state();
} }
...@@ -197,9 +188,8 @@ static struct sysrq_key_op sysrq_showstate_op = { ...@@ -197,9 +188,8 @@ static struct sysrq_key_op sysrq_showstate_op = {
.enable_mask = SYSRQ_ENABLE_DUMP, .enable_mask = SYSRQ_ENABLE_DUMP,
}; };
static void sysrq_handle_showmem(int key, struct pt_regs *pt_regs, static void sysrq_handle_showmem(int key, struct pt_regs *pt_regs,
struct tty_struct *tty) struct tty_struct *tty)
{ {
show_mem(); show_mem();
} }
...@@ -210,13 +200,9 @@ static struct sysrq_key_op sysrq_showmem_op = { ...@@ -210,13 +200,9 @@ static struct sysrq_key_op sysrq_showmem_op = {
.enable_mask = SYSRQ_ENABLE_DUMP, .enable_mask = SYSRQ_ENABLE_DUMP,
}; };
/* SHOW SYSRQ HANDLERS BLOCK */ /*
* Signal sysrq helper function. Sends a signal to all user processes.
*/
/* SIGNAL SYSRQ HANDLERS BLOCK */
/* signal sysrq helper function
* Sends a signal to all user processes */
static void send_sig_all(int sig) static void send_sig_all(int sig)
{ {
struct task_struct *p; struct task_struct *p;
...@@ -229,7 +215,7 @@ static void send_sig_all(int sig) ...@@ -229,7 +215,7 @@ static void send_sig_all(int sig)
} }
static void sysrq_handle_term(int key, struct pt_regs *pt_regs, static void sysrq_handle_term(int key, struct pt_regs *pt_regs,
struct tty_struct *tty) struct tty_struct *tty)
{ {
send_sig_all(SIGTERM); send_sig_all(SIGTERM);
console_loglevel = 8; console_loglevel = 8;
...@@ -243,7 +229,8 @@ static struct sysrq_key_op sysrq_term_op = { ...@@ -243,7 +229,8 @@ static struct sysrq_key_op sysrq_term_op = {
static void moom_callback(void *ignored) 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); static DECLARE_WORK(moom_work, moom_callback, NULL);
...@@ -260,7 +247,7 @@ static struct sysrq_key_op sysrq_moom_op = { ...@@ -260,7 +247,7 @@ static struct sysrq_key_op sysrq_moom_op = {
}; };
static void sysrq_handle_kill(int key, struct pt_regs *pt_regs, static void sysrq_handle_kill(int key, struct pt_regs *pt_regs,
struct tty_struct *tty) struct tty_struct *tty)
{ {
send_sig_all(SIGKILL); send_sig_all(SIGKILL);
console_loglevel = 8; console_loglevel = 8;
...@@ -272,8 +259,6 @@ static struct sysrq_key_op sysrq_kill_op = { ...@@ -272,8 +259,6 @@ static struct sysrq_key_op sysrq_kill_op = {
.enable_mask = SYSRQ_ENABLE_SIGNAL, .enable_mask = SYSRQ_ENABLE_SIGNAL,
}; };
/* END SIGNAL SYSRQ HANDLERS BLOCK */
static void sysrq_handle_unrt(int key, struct pt_regs *pt_regs, static void sysrq_handle_unrt(int key, struct pt_regs *pt_regs,
struct tty_struct *tty) struct tty_struct *tty)
{ {
...@@ -288,110 +273,99 @@ static struct sysrq_key_op sysrq_unrt_op = { ...@@ -288,110 +273,99 @@ static struct sysrq_key_op sysrq_unrt_op = {
/* Key Operations table and lock */ /* Key Operations table and lock */
static DEFINE_SPINLOCK(sysrq_key_table_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] = { static struct sysrq_key_op *sysrq_key_table[36] = {
/* 0 */ &sysrq_loglevel_op, &sysrq_loglevel_op, /* 0 */
/* 1 */ &sysrq_loglevel_op, &sysrq_loglevel_op, /* 1 */
/* 2 */ &sysrq_loglevel_op, &sysrq_loglevel_op, /* 2 */
/* 3 */ &sysrq_loglevel_op, &sysrq_loglevel_op, /* 3 */
/* 4 */ &sysrq_loglevel_op, &sysrq_loglevel_op, /* 4 */
/* 5 */ &sysrq_loglevel_op, &sysrq_loglevel_op, /* 5 */
/* 6 */ &sysrq_loglevel_op, &sysrq_loglevel_op, /* 6 */
/* 7 */ &sysrq_loglevel_op, &sysrq_loglevel_op, /* 7 */
/* 8 */ &sysrq_loglevel_op, &sysrq_loglevel_op, /* 8 */
/* 9 */ &sysrq_loglevel_op, &sysrq_loglevel_op, /* 9 */
/* a */ NULL, /* Don't use for system provided sysrqs,
it is handled specially on the sparc /*
and will never arrive */ * Don't use for system provided sysrqs, it is handled specially on
/* b */ &sysrq_reboot_op, * sparc and will never arrive
#ifdef CONFIG_KEXEC */
/* c */ &sysrq_crashdump_op, NULL, /* a */
#else &sysrq_reboot_op, /* b */
/* c */ NULL, &sysrq_crashdump_op, /* c */
#endif &sysrq_showlocks_op, /* d */
#ifdef CONFIG_DEBUG_MUTEXES &sysrq_term_op, /* e */
/* d */ &sysrq_showlocks_op, &sysrq_moom_op, /* f */
#else NULL, /* g */
/* d */ NULL, NULL, /* h */
#endif &sysrq_kill_op, /* i */
/* e */ &sysrq_term_op, NULL, /* j */
/* f */ &sysrq_moom_op, &sysrq_SAK_op, /* k */
/* g */ NULL, NULL, /* l */
/* h */ NULL, &sysrq_showmem_op, /* m */
/* i */ &sysrq_kill_op, &sysrq_unrt_op, /* n */
/* j */ NULL, /* This will often be registered as 'Off' at init time */
#ifdef CONFIG_VT NULL, /* o */
/* k */ &sysrq_SAK_op, &sysrq_showregs_op, /* p */
#else NULL, /* q */
/* k */ NULL, &sysrq_unraw_op, /* r */
#endif &sysrq_sync_op, /* s */
/* l */ NULL, &sysrq_showstate_op, /* t */
/* m */ &sysrq_showmem_op, &sysrq_mountro_op, /* u */
/* n */ &sysrq_unrt_op, /* May be assigned at init time by SMP VOYAGER */
/* o */ NULL, /* This will often be registered NULL, /* v */
as 'Off' at init time */ NULL, /* w */
/* p */ &sysrq_showregs_op, NULL, /* x */
/* q */ NULL, NULL, /* y */
#ifdef CONFIG_VT NULL /* z */
/* 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 */ /* key2index calculation, -1 on invalid index */
static int sysrq_key_table_key2index(int key) { static int sysrq_key_table_key2index(int key)
{
int retval; int retval;
if ((key >= '0') && (key <= '9')) {
if ((key >= '0') && (key <= '9'))
retval = key - '0'; retval = key - '0';
} else if ((key >= 'a') && (key <= 'z')) { else if ((key >= 'a') && (key <= 'z'))
retval = key + 10 - 'a'; retval = key + 10 - 'a';
} else { else
retval = -1; retval = -1;
}
return retval; return retval;
} }
/* /*
* get and put functions for the table, exposed to modules. * get and put functions for the table, exposed to modules.
*/ */
struct sysrq_key_op *__sysrq_get_key_op(int key)
struct sysrq_key_op *__sysrq_get_key_op (int key) { {
struct sysrq_key_op *op_p; struct sysrq_key_op *op_p = NULL;
int i; int i;
i = sysrq_key_table_key2index(key); 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; return op_p;
} }
static void __sysrq_put_key_op (int key, struct sysrq_key_op *op_p) { static void __sysrq_put_key_op(int key, struct sysrq_key_op *op_p)
int i; {
int i = sysrq_key_table_key2index(key);
i = sysrq_key_table_key2index(key);
if (i != -1) if (i != -1)
sysrq_key_table[i] = op_p; sysrq_key_table[i] = op_p;
} }
/* /*
* This is the non-locking version of handle_sysrq * This is the non-locking version of handle_sysrq. It must/can only be called
* It must/can only be called by sysrq key handlers, * by sysrq key handlers, as they are inside of the lock
* as they are inside of the lock
*/ */
void __handle_sysrq(int key, struct pt_regs *pt_regs, struct tty_struct *tty,
void __handle_sysrq(int key, struct pt_regs *pt_regs, struct tty_struct *tty, int check_mask) int check_mask)
{ {
struct sysrq_key_op *op_p; struct sysrq_key_op *op_p;
int orig_log_level; int orig_log_level;
int i, j; int i;
unsigned long flags; unsigned long flags;
spin_lock_irqsave(&sysrq_key_table_lock, 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 ...@@ -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); op_p = __sysrq_get_key_op(key);
if (op_p) { 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 || if (!check_mask || sysrq_enabled == 1 ||
(sysrq_enabled & op_p->enable_mask)) { (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; console_loglevel = orig_log_level;
op_p->handler(key, pt_regs, tty); op_p->handler(key, pt_regs, tty);
} } else {
else
printk("This sysrq operation is disabled.\n"); printk("This sysrq operation is disabled.\n");
}
} else { } else {
printk("HELP : "); printk("HELP : ");
/* Only print the help msg once per handler */ /* Only print the help msg once per handler */
for (i=0; i<SYSRQ_KEY_TABLE_LENGTH; i++) for (i = 0; i < ARRAY_SIZE(sysrq_key_table); i++) {
if (sysrq_key_table[i]) { if (sysrq_key_table[i]) {
for (j=0; sysrq_key_table[i] != sysrq_key_table[j]; j++); int j;
if (j == i)
printk ("%s ", sysrq_key_table[i]->help_msg); 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; console_loglevel = orig_log_level;
} }
spin_unlock_irqrestore(&sysrq_key_table_lock, flags); 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 ...@@ -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 * This function is called by the keyboard handler when SysRq is pressed
* and any other keycode arrives. * and any other keycode arrives.
*/ */
void handle_sysrq(int key, struct pt_regs *pt_regs, struct tty_struct *tty) void handle_sysrq(int key, struct pt_regs *pt_regs, struct tty_struct *tty)
{ {
if (!sysrq_enabled) if (!sysrq_enabled)
return; return;
__handle_sysrq(key, pt_regs, tty, 1); __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, 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; int retval;
unsigned long flags; unsigned long flags;
...@@ -452,7 +435,6 @@ static int __sysrq_swap_key_ops(int key, struct sysrq_key_op *insert_op_p, ...@@ -452,7 +435,6 @@ static int __sysrq_swap_key_ops(int key, struct sysrq_key_op *insert_op_p,
retval = -1; retval = -1;
} }
spin_unlock_irqrestore(&sysrq_key_table_lock, flags); spin_unlock_irqrestore(&sysrq_key_table_lock, flags);
return retval; return retval;
} }
...@@ -460,12 +442,10 @@ int register_sysrq_key(int key, struct sysrq_key_op *op_p) ...@@ -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); 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) int unregister_sysrq_key(int key, struct sysrq_key_op *op_p)
{ {
return __sysrq_swap_key_ops(key, NULL, 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); EXPORT_SYMBOL(unregister_sysrq_key);
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