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 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
  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
  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
  42 static inline unsigned long hw_breakpoint_addr(struct perf_event *bp)
  43 {
  44         return bp->attr.bp_addr;
  45 }
  46
  47 static inline int hw_breakpoint_type(struct perf_event *bp)
  48 {
  49         return bp->attr.bp_type;
  50 }
  51
  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
  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
 103 static inline int __init init_hw_breakpoint(void) { return 0; }
 104
 105 static inline struct perf_event *
 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
 111 modify_user_hw_breakpoint(struct perf_event *bp,
 112                           struct perf_event_attr *attr) { return -ENOSYS; }
 113 static inline int
 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 *
 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 *
 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
 127 register_perf_hw_breakpoint(struct perf_event *bp)      { return -ENOSYS; }
 128 static inline void unregister_hw_breakpoint(struct perf_event *bp)      { }
 129 static inline void
 130 unregister_wide_hw_breakpoint(struct perf_event * __percpu *cpu_events) { }
 131 static inline bool hw_breakpoint_is_used(void)          { return false; }
 132
 133 static inline int
 134 reserve_bp_slot(struct perf_event *bp)                  {return -ENOSYS; }
 135 static inline void release_bp_slot(struct perf_event *bp)               { }
 136
 137 static inline void flush_ptrace_hw_breakpoint(struct task_struct *tsk)  { }
 138
 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 */