xref: /linux-6.15/include/linux/hw_breakpoint.h (revision 71ccc212)
1 #ifndef _LINUX_HW_BREAKPOINT_H
2 #define _LINUX_HW_BREAKPOINT_H
3 
4 enum {
5 	HW_BREAKPOINT_LEN_1 = 1,
6 	HW_BREAKPOINT_LEN_2 = 2,
7 	HW_BREAKPOINT_LEN_4 = 4,
8 	HW_BREAKPOINT_LEN_8 = 8,
9 };
10 
11 enum {
12 	HW_BREAKPOINT_EMPTY	= 0,
13 	HW_BREAKPOINT_R		= 1,
14 	HW_BREAKPOINT_W		= 2,
15 	HW_BREAKPOINT_RW	= HW_BREAKPOINT_R | HW_BREAKPOINT_W,
16 	HW_BREAKPOINT_X		= 4,
17 	HW_BREAKPOINT_INVALID   = HW_BREAKPOINT_RW | HW_BREAKPOINT_X,
18 };
19 
20 enum bp_type_idx {
21 	TYPE_INST 	= 0,
22 #ifdef CONFIG_HAVE_MIXED_BREAKPOINTS_REGS
23 	TYPE_DATA	= 0,
24 #else
25 	TYPE_DATA	= 1,
26 #endif
27 	TYPE_MAX
28 };
29 
30 #ifdef __KERNEL__
31 
32 #include <linux/perf_event.h>
33 
34 #ifdef CONFIG_HAVE_HW_BREAKPOINT
35 
36 static inline void hw_breakpoint_init(struct perf_event_attr *attr)
37 {
38 	memset(attr, 0, sizeof(*attr));
39 
40 	attr->type = PERF_TYPE_BREAKPOINT;
41 	attr->size = sizeof(*attr);
42 	/*
43 	 * As it's for in-kernel or ptrace use, we want it to be pinned
44 	 * and to call its callback every hits.
45 	 */
46 	attr->pinned = 1;
47 	attr->sample_period = 1;
48 }
49 
50 static inline void ptrace_breakpoint_init(struct perf_event_attr *attr)
51 {
52 	hw_breakpoint_init(attr);
53 	attr->exclude_kernel = 1;
54 }
55 
56 static inline unsigned long hw_breakpoint_addr(struct perf_event *bp)
57 {
58 	return bp->attr.bp_addr;
59 }
60 
61 static inline int hw_breakpoint_type(struct perf_event *bp)
62 {
63 	return bp->attr.bp_type;
64 }
65 
66 static inline unsigned long hw_breakpoint_len(struct perf_event *bp)
67 {
68 	return bp->attr.bp_len;
69 }
70 
71 extern struct perf_event *
72 register_user_hw_breakpoint(struct perf_event_attr *attr,
73 			    perf_overflow_handler_t triggered,
74 			    struct task_struct *tsk);
75 
76 /* FIXME: only change from the attr, and don't unregister */
77 extern int
78 modify_user_hw_breakpoint(struct perf_event *bp, struct perf_event_attr *attr);
79 
80 /*
81  * Kernel breakpoints are not associated with any particular thread.
82  */
83 extern struct perf_event *
84 register_wide_hw_breakpoint_cpu(struct perf_event_attr *attr,
85 				perf_overflow_handler_t	triggered,
86 				int cpu);
87 
88 extern struct perf_event * __percpu *
89 register_wide_hw_breakpoint(struct perf_event_attr *attr,
90 			    perf_overflow_handler_t triggered);
91 
92 extern int register_perf_hw_breakpoint(struct perf_event *bp);
93 extern int __register_perf_hw_breakpoint(struct perf_event *bp);
94 extern void unregister_hw_breakpoint(struct perf_event *bp);
95 extern void unregister_wide_hw_breakpoint(struct perf_event * __percpu *cpu_events);
96 
97 extern int dbg_reserve_bp_slot(struct perf_event *bp);
98 extern int dbg_release_bp_slot(struct perf_event *bp);
99 extern int reserve_bp_slot(struct perf_event *bp);
100 extern void release_bp_slot(struct perf_event *bp);
101 
102 extern void flush_ptrace_hw_breakpoint(struct task_struct *tsk);
103 
104 static inline struct arch_hw_breakpoint *counter_arch_bp(struct perf_event *bp)
105 {
106 	return &bp->hw.info;
107 }
108 
109 #else /* !CONFIG_HAVE_HW_BREAKPOINT */
110 
111 static inline struct perf_event *
112 register_user_hw_breakpoint(struct perf_event_attr *attr,
113 			    perf_overflow_handler_t triggered,
114 			    struct task_struct *tsk)	{ return NULL; }
115 static inline int
116 modify_user_hw_breakpoint(struct perf_event *bp,
117 			  struct perf_event_attr *attr)	{ return -ENOSYS; }
118 static inline struct perf_event *
119 register_wide_hw_breakpoint_cpu(struct perf_event_attr *attr,
120 				perf_overflow_handler_t	 triggered,
121 				int cpu)		{ return NULL; }
122 static inline struct perf_event * __percpu *
123 register_wide_hw_breakpoint(struct perf_event_attr *attr,
124 			    perf_overflow_handler_t triggered)	{ return NULL; }
125 static inline int
126 register_perf_hw_breakpoint(struct perf_event *bp)	{ return -ENOSYS; }
127 static inline int
128 __register_perf_hw_breakpoint(struct perf_event *bp) 	{ return -ENOSYS; }
129 static inline void unregister_hw_breakpoint(struct perf_event *bp)	{ }
130 static inline void
131 unregister_wide_hw_breakpoint(struct perf_event * __percpu *cpu_events)	{ }
132 static inline int
133 reserve_bp_slot(struct perf_event *bp)			{return -ENOSYS; }
134 static inline void release_bp_slot(struct perf_event *bp) 		{ }
135 
136 static inline void flush_ptrace_hw_breakpoint(struct task_struct *tsk)	{ }
137 
138 static inline struct arch_hw_breakpoint *counter_arch_bp(struct perf_event *bp)
139 {
140 	return NULL;
141 }
142 
143 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
144 #endif /* __KERNEL__ */
145 
146 #endif /* _LINUX_HW_BREAKPOINT_H */
147