xref: /linux-6.15/include/linux/jump_label.h (revision facb4edc)
1 #ifndef _LINUX_JUMP_LABEL_H
2 #define _LINUX_JUMP_LABEL_H
3 
4 #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
5 # include <asm/jump_label.h>
6 # define HAVE_JUMP_LABEL
7 #endif
8 
9 enum jump_label_type {
10 	JUMP_LABEL_ENABLE,
11 	JUMP_LABEL_DISABLE
12 };
13 
14 struct module;
15 
16 #ifdef HAVE_JUMP_LABEL
17 
18 extern struct jump_entry __start___jump_table[];
19 extern struct jump_entry __stop___jump_table[];
20 
21 extern void jump_label_lock(void);
22 extern void jump_label_unlock(void);
23 extern void arch_jump_label_transform(struct jump_entry *entry,
24 				 enum jump_label_type type);
25 extern void arch_jump_label_text_poke_early(jump_label_t addr);
26 extern void jump_label_update(unsigned long key, enum jump_label_type type);
27 extern void jump_label_apply_nops(struct module *mod);
28 extern int jump_label_text_reserved(void *start, void *end);
29 
30 #define jump_label_enable(key) \
31 	jump_label_update((unsigned long)key, JUMP_LABEL_ENABLE);
32 
33 #define jump_label_disable(key) \
34 	jump_label_update((unsigned long)key, JUMP_LABEL_DISABLE);
35 
36 #else
37 
38 #define JUMP_LABEL(key, label)			\
39 do {						\
40 	if (unlikely(*key))			\
41 		goto label;			\
42 } while (0)
43 
44 #define jump_label_enable(cond_var)	\
45 do {					\
46        *(cond_var) = 1;			\
47 } while (0)
48 
49 #define jump_label_disable(cond_var)	\
50 do {					\
51        *(cond_var) = 0;			\
52 } while (0)
53 
54 static inline int jump_label_apply_nops(struct module *mod)
55 {
56 	return 0;
57 }
58 
59 static inline int jump_label_text_reserved(void *start, void *end)
60 {
61 	return 0;
62 }
63 
64 static inline void jump_label_lock(void) {}
65 static inline void jump_label_unlock(void) {}
66 
67 #endif
68 
69 #define COND_STMT(key, stmt)					\
70 do {								\
71 	__label__ jl_enabled;					\
72 	JUMP_LABEL(key, jl_enabled);				\
73 	if (0) {						\
74 jl_enabled:							\
75 		stmt;						\
76 	}							\
77 } while (0)
78 
79 #endif
80