include/linux/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
  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 */