xref: /linux-6.15/include/linux/hw_breakpoint.h (revision e00a844a)
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 
57 /*
58  * Kernel breakpoints are not associated with any particular thread.
59  */
60 extern struct perf_event *
61 register_wide_hw_breakpoint_cpu(struct perf_event_attr *attr,
62 				perf_overflow_handler_t	triggered,
63 				void *context,
64 				int cpu);
65 
66 extern struct perf_event * __percpu *
67 register_wide_hw_breakpoint(struct perf_event_attr *attr,
68 			    perf_overflow_handler_t triggered,
69 			    void *context);
70 
71 extern int register_perf_hw_breakpoint(struct perf_event *bp);
72 extern int __register_perf_hw_breakpoint(struct perf_event *bp);
73 extern void unregister_hw_breakpoint(struct perf_event *bp);
74 extern void unregister_wide_hw_breakpoint(struct perf_event * __percpu *cpu_events);
75 
76 extern int dbg_reserve_bp_slot(struct perf_event *bp);
77 extern int dbg_release_bp_slot(struct perf_event *bp);
78 extern int reserve_bp_slot(struct perf_event *bp);
79 extern void release_bp_slot(struct perf_event *bp);
80 
81 extern void flush_ptrace_hw_breakpoint(struct task_struct *tsk);
82 
83 static inline struct arch_hw_breakpoint *counter_arch_bp(struct perf_event *bp)
84 {
85 	return &bp->hw.info;
86 }
87 
88 #else /* !CONFIG_HAVE_HW_BREAKPOINT */
89 
90 static inline int __init init_hw_breakpoint(void) { return 0; }
91 
92 static inline struct perf_event *
93 register_user_hw_breakpoint(struct perf_event_attr *attr,
94 			    perf_overflow_handler_t triggered,
95 			    void *context,
96 			    struct task_struct *tsk)	{ return NULL; }
97 static inline int
98 modify_user_hw_breakpoint(struct perf_event *bp,
99 			  struct perf_event_attr *attr)	{ return -ENOSYS; }
100 static inline struct perf_event *
101 register_wide_hw_breakpoint_cpu(struct perf_event_attr *attr,
102 				perf_overflow_handler_t	 triggered,
103 				void *context,
104 				int cpu)		{ return NULL; }
105 static inline struct perf_event * __percpu *
106 register_wide_hw_breakpoint(struct perf_event_attr *attr,
107 			    perf_overflow_handler_t triggered,
108 			    void *context)		{ return NULL; }
109 static inline int
110 register_perf_hw_breakpoint(struct perf_event *bp)	{ return -ENOSYS; }
111 static inline int
112 __register_perf_hw_breakpoint(struct perf_event *bp) 	{ return -ENOSYS; }
113 static inline void unregister_hw_breakpoint(struct perf_event *bp)	{ }
114 static inline void
115 unregister_wide_hw_breakpoint(struct perf_event * __percpu *cpu_events)	{ }
116 static inline int
117 reserve_bp_slot(struct perf_event *bp)			{return -ENOSYS; }
118 static inline void release_bp_slot(struct perf_event *bp) 		{ }
119 
120 static inline void flush_ptrace_hw_breakpoint(struct task_struct *tsk)	{ }
121 
122 static inline struct arch_hw_breakpoint *counter_arch_bp(struct perf_event *bp)
123 {
124 	return NULL;
125 }
126 
127 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
128 #endif /* _LINUX_HW_BREAKPOINT_H */
129