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 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
  78 extern int dbg_reserve_bp_slot(struct perf_event *bp);
  79 extern int dbg_release_bp_slot(struct perf_event *bp);
  80 extern int reserve_bp_slot(struct perf_event *bp);
  81 extern void release_bp_slot(struct perf_event *bp);
  82 int hw_breakpoint_weight(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
  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
  96 static inline int __init init_hw_breakpoint(void) { return 0; }
  97
  98 static inline struct perf_event *
  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
 104 modify_user_hw_breakpoint(struct perf_event *bp,
 105                           struct perf_event_attr *attr) { return -ENOSYS; }
 106 static inline int
 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 *
 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 *
 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
 120 register_perf_hw_breakpoint(struct perf_event *bp)      { return -ENOSYS; }
 121 static inline void unregister_hw_breakpoint(struct perf_event *bp)      { }
 122 static inline void
 123 unregister_wide_hw_breakpoint(struct perf_event * __percpu *cpu_events) { }
 124 static inline int
 125 reserve_bp_slot(struct perf_event *bp)                  {return -ENOSYS; }
 126 static inline void release_bp_slot(struct perf_event *bp)               { }
 127
 128 static inline void flush_ptrace_hw_breakpoint(struct task_struct *tsk)  { }
 129
 130 static inline struct arch_hw_breakpoint *counter_arch_bp(struct perf_event *bp)
 131 {
 132         return NULL;
 133 }
 134
 135 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
 136 #endif /* _LINUX_HW_BREAKPOINT_H */