linux/include/linux/sysrq.h
Ingo Molnar 5d6f647fc6 [PATCH] debug: add sysrq_always_enabled boot option
Most distributions enable sysrq support but set it to 0 by default.  Add a
sysrq_always_enabled boot option to always-enable sysrq keys.  Useful for
debugging - without having to modify the disribution's config files (which
might not be possible if the kernel is on a live CD, etc.).

Also, while at it, clean up the sysrq interfaces.

[bunk@stusta.de: make sysrq_always_enabled_setup() static]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-13 09:05:50 -08:00

78 lines
1.8 KiB
C

/* -*- linux-c -*-
*
* $Id: sysrq.h,v 1.3 1997/07/17 11:54:33 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
*/
#ifndef _LINUX_SYSRQ_H
#define _LINUX_SYSRQ_H
struct pt_regs;
struct tty_struct;
/* Possible values of bitmask for enabling sysrq functions */
/* 0x0001 is reserved for enable everything */
#define SYSRQ_ENABLE_LOG 0x0002
#define SYSRQ_ENABLE_KEYBOARD 0x0004
#define SYSRQ_ENABLE_DUMP 0x0008
#define SYSRQ_ENABLE_SYNC 0x0010
#define SYSRQ_ENABLE_REMOUNT 0x0020
#define SYSRQ_ENABLE_SIGNAL 0x0040
#define SYSRQ_ENABLE_BOOT 0x0080
#define SYSRQ_ENABLE_RTNICE 0x0100
struct sysrq_key_op {
void (*handler)(int, struct tty_struct *);
char *help_msg;
char *action_msg;
int enable_mask;
};
#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);
#else
static inline int sysrq_on(void)
{
return 0;
}
static inline int __reterr(void)
{
return -EINVAL;
}
static inline void handle_sysrq(int key, struct tty_struct *tty)
{
}
#define register_sysrq_key(ig,nore) __reterr()
#define unregister_sysrq_key(ig,nore) __reterr()
#endif
#endif /* _LINUX_SYSRQ_H */