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			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>
		
			
				
	
	
		
			78 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			78 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* -*- linux-c -*-
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|  *
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|  *	$Id: sysrq.h,v 1.3 1997/07/17 11:54:33 mj Exp $
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|  *
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|  *	Linux Magic System Request Key Hacks
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|  *
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|  *	(c) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
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|  *
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|  *	(c) 2000 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
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|  *	overhauled to use key registration
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|  *	based upon discusions in irc://irc.openprojects.net/#kernelnewbies
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|  */
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| 
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| #ifndef _LINUX_SYSRQ_H
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| #define _LINUX_SYSRQ_H
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| 
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| struct pt_regs;
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| struct tty_struct;
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| 
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| /* Possible values of bitmask for enabling sysrq functions */
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| /* 0x0001 is reserved for enable everything */
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| #define SYSRQ_ENABLE_LOG	0x0002
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| #define SYSRQ_ENABLE_KEYBOARD	0x0004
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| #define SYSRQ_ENABLE_DUMP	0x0008
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| #define SYSRQ_ENABLE_SYNC	0x0010
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| #define SYSRQ_ENABLE_REMOUNT	0x0020
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| #define SYSRQ_ENABLE_SIGNAL	0x0040
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| #define SYSRQ_ENABLE_BOOT	0x0080
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| #define SYSRQ_ENABLE_RTNICE	0x0100
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| 
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| struct sysrq_key_op {
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| 	void (*handler)(int, struct tty_struct *);
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| 	char *help_msg;
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| 	char *action_msg;
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| 	int enable_mask;
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| };
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| 
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| #ifdef CONFIG_MAGIC_SYSRQ
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| 
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| extern int sysrq_on(void);
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| 
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| /*
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|  * Do not use this one directly:
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|  */
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| extern int __sysrq_enabled;
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| 
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| /* Generic SysRq interface -- you may call it from any device driver, supplying
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|  * ASCII code of the key, pointer to registers and kbd/tty structs (if they
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|  * are available -- else NULL's).
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|  */
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| 
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| void handle_sysrq(int key, struct tty_struct *tty);
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| void __handle_sysrq(int key, struct tty_struct *tty, int check_mask);
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| int register_sysrq_key(int key, struct sysrq_key_op *op);
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| int unregister_sysrq_key(int key, struct sysrq_key_op *op);
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| struct sysrq_key_op *__sysrq_get_key_op(int key);
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| 
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| #else
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| 
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| static inline int sysrq_on(void)
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| {
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| 	return 0;
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| }
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| static inline int __reterr(void)
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| {
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| 	return -EINVAL;
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| }
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| static inline void handle_sysrq(int key, struct tty_struct *tty)
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| {
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| }
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| 
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| #define register_sysrq_key(ig,nore) __reterr()
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| #define unregister_sysrq_key(ig,nore) __reterr()
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| 
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| #endif
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| 
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| #endif /* _LINUX_SYSRQ_H */
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