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