LXR linux/include/linux/hw

   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
  10extern int __init init_hw_breakpoint(void);
  11
  12static 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
  26static inline void ptrace_breakpoint_init(struct perf_event_attr *attr)
  27{
  28        hw_breakpoint_init(attr);
  29        attr->exclude_kernel = 1;
  30}
  31
  32static inline unsigned long hw_breakpoint_addr(struct perf_event *bp)
  33{
  34        return bp->attr.bp_addr;
  35}
  36
  37static inline int hw_breakpoint_type(struct perf_event *bp)
  38{
  39        return bp->attr.bp_type;
  40}
  41
  42static inline unsigned long hw_breakpoint_len(struct perf_event *bp)
  43{
  44        return bp->attr.bp_len;
  45}
  46
  47extern struct perf_event *
  48register_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 */
  54extern int
  55modify_user_hw_breakpoint(struct perf_event *bp, struct perf_event_attr *attr);
  56extern int
  57modify_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 */
  63extern struct perf_event *
  64register_wide_hw_breakpoint_cpu(struct perf_event_attr *attr,
  65                                perf_overflow_handler_t triggered,
  66                                void *context,
  67                                int cpu);
  68
  69extern struct perf_event * __percpu *
  70register_wide_hw_breakpoint(struct perf_event_attr *attr,
  71                            perf_overflow_handler_t triggered,
  72                            void *context);
  73
  74extern int register_perf_hw_breakpoint(struct perf_event *bp);
  75extern int __register_perf_hw_breakpoint(struct perf_event *bp);
  76extern void unregister_hw_breakpoint(struct perf_event *bp);
  77extern void unregister_wide_hw_breakpoint(struct perf_event * __percpu *cpu_events);
  78
  79extern int dbg_reserve_bp_slot(struct perf_event *bp);
  80extern int dbg_release_bp_slot(struct perf_event *bp);
  81extern int reserve_bp_slot(struct perf_event *bp);
  82extern void release_bp_slot(struct perf_event *bp);
  83
  84extern void flush_ptrace_hw_breakpoint(struct task_struct *tsk);
  85
  86static inline struct arch_hw_breakpoint *counter_arch_bp(struct perf_event *bp)
  87{
  88        return &bp->hw.info;
  89}
  90
  91#else /* !CONFIG_HAVE_HW_BREAKPOINT */
  92
  93static inline int __init init_hw_breakpoint(void) { return 0; }
  94
  95static inline struct perf_event *
  96register_user_hw_breakpoint(struct perf_event_attr *attr,
  97                            perf_overflow_handler_t triggered,
  98                            void *context,
  99                            struct task_struct *tsk)    { return NULL; }
 100static inline int
 101modify_user_hw_breakpoint(struct perf_event *bp,
 102                          struct perf_event_attr *attr) { return -ENOSYS; }
 103static inline int
 104modify_user_hw_breakpoint_check(struct perf_event *bp, struct perf_event_attr *attr,
 105                                bool check)     { return -ENOSYS; }
 106
 107static inline struct perf_event *
 108register_wide_hw_breakpoint_cpu(struct perf_event_attr *attr,
 109                                perf_overflow_handler_t  triggered,
 110                                void *context,
 111                                int cpu)                { return NULL; }
 112static inline struct perf_event * __percpu *
 113register_wide_hw_breakpoint(struct perf_event_attr *attr,
 114                            perf_overflow_handler_t triggered,
 115                            void *context)              { return NULL; }
 116static inline int
 117register_perf_hw_breakpoint(struct perf_event *bp)      { return -ENOSYS; }
 118static inline int
 119__register_perf_hw_breakpoint(struct perf_event *bp)    { return -ENOSYS; }
 120static inline void unregister_hw_breakpoint(struct perf_event *bp)      { }
 121static inline void
 122unregister_wide_hw_breakpoint(struct perf_event * __percpu *cpu_events) { }
 123static inline int
 124reserve_bp_slot(struct perf_event *bp)                  {return -ENOSYS; }
 125static inline void release_bp_slot(struct perf_event *bp)               { }
 126
 127static inline void flush_ptrace_hw_breakpoint(struct task_struct *tsk)  { }
 128
 129static inline struct arch_hw_breakpoint *counter_arch_bp(struct perf_event *bp)
 130{
 131        return NULL;
 132}
 133
 134#endif /* CONFIG_HAVE_HW_BREAKPOINT */
 135#endif /* _LINUX_HW_BREAKPOINT_H */
 136