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
hw_breakpoint_init(struct perf_event_attr * attr)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
ptrace_breakpoint_init(struct perf_event_attr * attr)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
hw_breakpoint_addr(struct perf_event * bp)32 static inline unsigned long hw_breakpoint_addr(struct perf_event *bp)
33 {
34 return bp->attr.bp_addr;
35 }
36
hw_breakpoint_type(struct perf_event * bp)37 static inline int hw_breakpoint_type(struct perf_event *bp)
38 {
39 return bp->attr.bp_type;
40 }
41
hw_breakpoint_len(struct perf_event * bp)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 void unregister_hw_breakpoint(struct perf_event *bp);
76 extern void unregister_wide_hw_breakpoint(struct perf_event * __percpu *cpu_events);
77 extern bool hw_breakpoint_is_used(void);
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 arch_reserve_bp_slot(struct perf_event *bp);
84 void arch_release_bp_slot(struct perf_event *bp);
85 void arch_unregister_hw_breakpoint(struct perf_event *bp);
86
87 extern void flush_ptrace_hw_breakpoint(struct task_struct *tsk);
88
counter_arch_bp(struct perf_event * bp)89 static inline struct arch_hw_breakpoint *counter_arch_bp(struct perf_event *bp)
90 {
91 return &bp->hw.info;
92 }
93
94 #else /* !CONFIG_HAVE_HW_BREAKPOINT */
95
init_hw_breakpoint(void)96 static inline int __init init_hw_breakpoint(void) { return 0; }
97
98 static inline struct perf_event *
register_user_hw_breakpoint(struct perf_event_attr * attr,perf_overflow_handler_t triggered,void * context,struct task_struct * tsk)99 register_user_hw_breakpoint(struct perf_event_attr *attr,
100 perf_overflow_handler_t triggered,
101 void *context,
102 struct task_struct *tsk) { return NULL; }
103 static inline int
modify_user_hw_breakpoint(struct perf_event * bp,struct perf_event_attr * attr)104 modify_user_hw_breakpoint(struct perf_event *bp,
105 struct perf_event_attr *attr) { return -ENOSYS; }
106 static inline int
modify_user_hw_breakpoint_check(struct perf_event * bp,struct perf_event_attr * attr,bool check)107 modify_user_hw_breakpoint_check(struct perf_event *bp, struct perf_event_attr *attr,
108 bool check) { return -ENOSYS; }
109
110 static inline struct perf_event *
register_wide_hw_breakpoint_cpu(struct perf_event_attr * attr,perf_overflow_handler_t triggered,void * context,int cpu)111 register_wide_hw_breakpoint_cpu(struct perf_event_attr *attr,
112 perf_overflow_handler_t triggered,
113 void *context,
114 int cpu) { return NULL; }
115 static inline struct perf_event * __percpu *
register_wide_hw_breakpoint(struct perf_event_attr * attr,perf_overflow_handler_t triggered,void * context)116 register_wide_hw_breakpoint(struct perf_event_attr *attr,
117 perf_overflow_handler_t triggered,
118 void *context) { return NULL; }
119 static inline int
register_perf_hw_breakpoint(struct perf_event * bp)120 register_perf_hw_breakpoint(struct perf_event *bp) { return -ENOSYS; }
unregister_hw_breakpoint(struct perf_event * bp)121 static inline void unregister_hw_breakpoint(struct perf_event *bp) { }
122 static inline void
unregister_wide_hw_breakpoint(struct perf_event * __percpu * cpu_events)123 unregister_wide_hw_breakpoint(struct perf_event * __percpu *cpu_events) { }
hw_breakpoint_is_used(void)124 static inline bool hw_breakpoint_is_used(void) { return false; }
125
126 static inline int
reserve_bp_slot(struct perf_event * bp)127 reserve_bp_slot(struct perf_event *bp) {return -ENOSYS; }
release_bp_slot(struct perf_event * bp)128 static inline void release_bp_slot(struct perf_event *bp) { }
129
flush_ptrace_hw_breakpoint(struct task_struct * tsk)130 static inline void flush_ptrace_hw_breakpoint(struct task_struct *tsk) { }
131
counter_arch_bp(struct perf_event * bp)132 static inline struct arch_hw_breakpoint *counter_arch_bp(struct perf_event *bp)
133 {
134 return NULL;
135 }
136
137 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
138 #endif /* _LINUX_HW_BREAKPOINT_H */
139