xref: /linux-6.15/include/linux/hw_breakpoint.h (revision 4de87f45)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_HW_BREAKPOINT_H
3 #define _LINUX_HW_BREAKPOINT_H
4 
5 #include <linux/perf_event.h>
6 #include <uapi/linux/hw_breakpoint.h>
7 
8 #ifdef CONFIG_HAVE_HW_BREAKPOINT
9 
10 extern int __init init_hw_breakpoint(void);
11 
12 static inline void hw_breakpoint_init(struct perf_event_attr *attr)
13 {
14 	memset(attr, 0, sizeof(*attr));
15 
16 	attr->type = PERF_TYPE_BREAKPOINT;
17 	attr->size = sizeof(*attr);
18 	/*
19 	 * As it's for in-kernel or ptrace use, we want it to be pinned
20 	 * and to call its callback every hits.
21 	 */
22 	attr->pinned = 1;
23 	attr->sample_period = 1;
24 }
25 
26 static inline void ptrace_breakpoint_init(struct perf_event_attr *attr)
27 {
28 	hw_breakpoint_init(attr);
29 	attr->exclude_kernel = 1;
30 }
31 
32 static inline unsigned long hw_breakpoint_addr(struct perf_event *bp)
33 {
34 	return bp->attr.bp_addr;
35 }
36 
37 static inline int hw_breakpoint_type(struct perf_event *bp)
38 {
39 	return bp->attr.bp_type;
40 }
41 
42 static inline unsigned long hw_breakpoint_len(struct perf_event *bp)
43 {
44 	return bp->attr.bp_len;
45 }
46 
47 extern struct perf_event *
48 register_user_hw_breakpoint(struct perf_event_attr *attr,
49 			    perf_overflow_handler_t triggered,
50 			    void *context,
51 			    struct task_struct *tsk);
52 
53 /* FIXME: only change from the attr, and don't unregister */
54 extern int
55 modify_user_hw_breakpoint(struct perf_event *bp, struct perf_event_attr *attr);
56 extern int
57 modify_user_hw_breakpoint_check(struct perf_event *bp, struct perf_event_attr *attr,
58 				bool check);
59 
60 /*
61  * Kernel breakpoints are not associated with any particular thread.
62  */
63 extern struct perf_event *
64 register_wide_hw_breakpoint_cpu(struct perf_event_attr *attr,
65 				perf_overflow_handler_t	triggered,
66 				void *context,
67 				int cpu);
68 
69 extern struct perf_event * __percpu *
70 register_wide_hw_breakpoint(struct perf_event_attr *attr,
71 			    perf_overflow_handler_t triggered,
72 			    void *context);
73 
74 extern int register_perf_hw_breakpoint(struct perf_event *bp);
75 extern int __register_perf_hw_breakpoint(struct perf_event *bp);
76 extern void unregister_hw_breakpoint(struct perf_event *bp);
77 extern void unregister_wide_hw_breakpoint(struct perf_event * __percpu *cpu_events);
78 
79 extern int dbg_reserve_bp_slot(struct perf_event *bp);
80 extern int dbg_release_bp_slot(struct perf_event *bp);
81 extern int reserve_bp_slot(struct perf_event *bp);
82 extern void release_bp_slot(struct perf_event *bp);
83 int hw_breakpoint_weight(struct perf_event *bp);
84 int arch_reserve_bp_slot(struct perf_event *bp);
85 void arch_release_bp_slot(struct perf_event *bp);
86 void arch_unregister_hw_breakpoint(struct perf_event *bp);
87 
88 extern void flush_ptrace_hw_breakpoint(struct task_struct *tsk);
89 
90 static inline struct arch_hw_breakpoint *counter_arch_bp(struct perf_event *bp)
91 {
92 	return &bp->hw.info;
93 }
94 
95 #else /* !CONFIG_HAVE_HW_BREAKPOINT */
96 
97 static inline int __init init_hw_breakpoint(void) { return 0; }
98 
99 static inline struct perf_event *
100 register_user_hw_breakpoint(struct perf_event_attr *attr,
101 			    perf_overflow_handler_t triggered,
102 			    void *context,
103 			    struct task_struct *tsk)	{ return NULL; }
104 static inline int
105 modify_user_hw_breakpoint(struct perf_event *bp,
106 			  struct perf_event_attr *attr)	{ return -ENOSYS; }
107 static inline int
108 modify_user_hw_breakpoint_check(struct perf_event *bp, struct perf_event_attr *attr,
109 				bool check)	{ return -ENOSYS; }
110 
111 static inline struct perf_event *
112 register_wide_hw_breakpoint_cpu(struct perf_event_attr *attr,
113 				perf_overflow_handler_t	 triggered,
114 				void *context,
115 				int cpu)		{ return NULL; }
116 static inline struct perf_event * __percpu *
117 register_wide_hw_breakpoint(struct perf_event_attr *attr,
118 			    perf_overflow_handler_t triggered,
119 			    void *context)		{ return NULL; }
120 static inline int
121 register_perf_hw_breakpoint(struct perf_event *bp)	{ return -ENOSYS; }
122 static inline int
123 __register_perf_hw_breakpoint(struct perf_event *bp) 	{ return -ENOSYS; }
124 static inline void unregister_hw_breakpoint(struct perf_event *bp)	{ }
125 static inline void
126 unregister_wide_hw_breakpoint(struct perf_event * __percpu *cpu_events)	{ }
127 static inline int
128 reserve_bp_slot(struct perf_event *bp)			{return -ENOSYS; }
129 static inline void release_bp_slot(struct perf_event *bp) 		{ }
130 
131 static inline void flush_ptrace_hw_breakpoint(struct task_struct *tsk)	{ }
132 
133 static inline struct arch_hw_breakpoint *counter_arch_bp(struct perf_event *bp)
134 {
135 	return NULL;
136 }
137 
138 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
139 #endif /* _LINUX_HW_BREAKPOINT_H */
140