xref: /linux-6.15/include/linux/sysrq.h (revision a115bc07)
1 /* -*- linux-c -*-
2  *
3  *	$Id: sysrq.h,v 1.3 1997/07/17 11:54:33 mj Exp $
4  *
5  *	Linux Magic System Request Key Hacks
6  *
7  *	(c) 1997 Martin Mares <[email protected]>
8  *
9  *	(c) 2000 Crutcher Dunnavant <[email protected]>
10  *	overhauled to use key registration
11  *	based upon discusions in irc://irc.openprojects.net/#kernelnewbies
12  */
13 
14 #ifndef _LINUX_SYSRQ_H
15 #define _LINUX_SYSRQ_H
16 
17 #include <linux/errno.h>
18 
19 struct pt_regs;
20 struct tty_struct;
21 
22 /* Possible values of bitmask for enabling sysrq functions */
23 /* 0x0001 is reserved for enable everything */
24 #define SYSRQ_ENABLE_LOG	0x0002
25 #define SYSRQ_ENABLE_KEYBOARD	0x0004
26 #define SYSRQ_ENABLE_DUMP	0x0008
27 #define SYSRQ_ENABLE_SYNC	0x0010
28 #define SYSRQ_ENABLE_REMOUNT	0x0020
29 #define SYSRQ_ENABLE_SIGNAL	0x0040
30 #define SYSRQ_ENABLE_BOOT	0x0080
31 #define SYSRQ_ENABLE_RTNICE	0x0100
32 
33 struct sysrq_key_op {
34 	void (*handler)(int, struct tty_struct *);
35 	char *help_msg;
36 	char *action_msg;
37 	int enable_mask;
38 };
39 
40 #ifdef CONFIG_MAGIC_SYSRQ
41 
42 extern int sysrq_on(void);
43 
44 /*
45  * Do not use this one directly:
46  */
47 extern int __sysrq_enabled;
48 
49 /* Generic SysRq interface -- you may call it from any device driver, supplying
50  * ASCII code of the key, pointer to registers and kbd/tty structs (if they
51  * are available -- else NULL's).
52  */
53 
54 void handle_sysrq(int key, struct tty_struct *tty);
55 void __handle_sysrq(int key, struct tty_struct *tty, int check_mask);
56 int register_sysrq_key(int key, struct sysrq_key_op *op);
57 int unregister_sysrq_key(int key, struct sysrq_key_op *op);
58 struct sysrq_key_op *__sysrq_get_key_op(int key);
59 
60 #else
61 
62 static inline int sysrq_on(void)
63 {
64 	return 0;
65 }
66 static inline int __reterr(void)
67 {
68 	return -EINVAL;
69 }
70 static inline void handle_sysrq(int key, struct tty_struct *tty)
71 {
72 }
73 
74 #define register_sysrq_key(ig,nore) __reterr()
75 #define unregister_sysrq_key(ig,nore) __reterr()
76 
77 #endif
78 
79 #endif /* _LINUX_SYSRQ_H */
80