hw_breakpoint.h

  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
 10enum 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
 20extern int __init init_hw_breakpoint(void);
 21
 22static 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
 36static inline void ptrace_breakpoint_init(struct perf_event_attr *attr)
 37{
 38	hw_breakpoint_init(attr);
 39	attr->exclude_kernel = 1;
 40}
 41
 42static inline unsigned long hw_breakpoint_addr(struct perf_event *bp)
 43{
 44	return bp->attr.bp_addr;
 45}
 46
 47static inline int hw_breakpoint_type(struct perf_event *bp)
 48{
 49	return bp->attr.bp_type;
 50}
 51
 52static inline unsigned long hw_breakpoint_len(struct perf_event *bp)
 53{
 54	return bp->attr.bp_len;
 55}
 56
 57extern struct perf_event *
 58register_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 */
 64extern int
 65modify_user_hw_breakpoint(struct perf_event *bp, struct perf_event_attr *attr);
 66extern int
 67modify_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 */
 73extern struct perf_event *
 74register_wide_hw_breakpoint_cpu(struct perf_event_attr *attr,
 75				perf_overflow_handler_t	triggered,
 76				void *context,
 77				int cpu);
 78
 79extern struct perf_event * __percpu *
 80register_wide_hw_breakpoint(struct perf_event_attr *attr,
 81			    perf_overflow_handler_t triggered,
 82			    void *context);
 83
 84extern int register_perf_hw_breakpoint(struct perf_event *bp);
 85extern void unregister_hw_breakpoint(struct perf_event *bp);
 86extern void unregister_wide_hw_breakpoint(struct perf_event * __percpu *cpu_events);
 87extern bool hw_breakpoint_is_used(void);
 88
 89extern int dbg_reserve_bp_slot(struct perf_event *bp);
 90extern int dbg_release_bp_slot(struct perf_event *bp);
 91extern int reserve_bp_slot(struct perf_event *bp);
 92extern void release_bp_slot(struct perf_event *bp);
 93
 94extern void flush_ptrace_hw_breakpoint(struct task_struct *tsk);
 95
 96static 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
103static inline int __init init_hw_breakpoint(void) { return 0; }
104
105static inline struct perf_event *
106register_user_hw_breakpoint(struct perf_event_attr *attr,
107			    perf_overflow_handler_t triggered,
108			    void *context,
109			    struct task_struct *tsk)	{ return NULL; }
110static inline int
111modify_user_hw_breakpoint(struct perf_event *bp,
112			  struct perf_event_attr *attr)	{ return -ENOSYS; }
113static inline int
114modify_user_hw_breakpoint_check(struct perf_event *bp, struct perf_event_attr *attr,
115				bool check)	{ return -ENOSYS; }
116
117static inline struct perf_event *
118register_wide_hw_breakpoint_cpu(struct perf_event_attr *attr,
119				perf_overflow_handler_t	 triggered,
120				void *context,
121				int cpu)		{ return NULL; }
122static inline struct perf_event * __percpu *
123register_wide_hw_breakpoint(struct perf_event_attr *attr,
124			    perf_overflow_handler_t triggered,
125			    void *context)		{ return NULL; }
126static inline int
127register_perf_hw_breakpoint(struct perf_event *bp)	{ return -ENOSYS; }
128static inline void unregister_hw_breakpoint(struct perf_event *bp)	{ }
129static inline void
130unregister_wide_hw_breakpoint(struct perf_event * __percpu *cpu_events)	{ }
131static inline bool hw_breakpoint_is_used(void)		{ return false; }
132
133static inline int
134reserve_bp_slot(struct perf_event *bp)			{return -ENOSYS; }
135static inline void release_bp_slot(struct perf_event *bp) 		{ }
136
137static inline void flush_ptrace_hw_breakpoint(struct task_struct *tsk)	{ }
138
139static 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 */