#ifndef _LINUX_KPROBES_H
  #define _LINUX_KPROBES_H
  /*
   *  Kernel Probes (KProbes)
   *  include/linux/kprobes.h
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
   *
   * Copyright (C) IBM Corporation, 2002, 2004
   *
   * 2002-Oct	Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel
   *		Probes initial implementation ( includes suggestions from
   *		Rusty Russell).
   * 2004-July	Suparna Bhattacharya <suparna@in.ibm.com> added jumper probes
   *		interface to access function arguments.

   * 2005-May	Hien Nguyen <hien@us.ibm.com> and Jim Keniston
   *		<jkenisto@us.ibm.com>  and Prasanna S Panchamukhi
   *		<prasanna@in.ibm.com> added function-return probes.

   */

  #include <linux/linkage.h>

  #include <linux/list.h>
  #include <linux/notifier.h>
  #include <linux/smp.h>

  #include <linux/percpu.h>

  #include <linux/spinlock.h>
  #include <linux/rcupdate.h>

  #include <linux/mutex.h>

  #ifdef CONFIG_KPROBES

  #include <asm/kprobes.h>

  /* kprobe_status settings */
  #define KPROBE_HIT_ACTIVE	0x00000001
  #define KPROBE_HIT_SS		0x00000002
  #define KPROBE_REENTER		0x00000004
  #define KPROBE_HIT_SSDONE	0x00000008

  /* Attach to insert probes on any functions which should be ignored*/

  #define __kprobes	__attribute__((__section__(".kprobes.text")))

  #else /* CONFIG_KPROBES */
  typedef int kprobe_opcode_t;
  struct arch_specific_insn {
  	int dummy;
  };

  #define __kprobes

  #endif /* CONFIG_KPROBES */

  struct kprobe;
  struct pt_regs;

  struct kretprobe;
  struct kretprobe_instance;

  typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *);
  typedef int (*kprobe_break_handler_t) (struct kprobe *, struct pt_regs *);
  typedef void (*kprobe_post_handler_t) (struct kprobe *, struct pt_regs *,
  				       unsigned long flags);
  typedef int (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *,
  				       int trapnr);

  typedef int (*kretprobe_handler_t) (struct kretprobe_instance *,
  				    struct pt_regs *);

  struct kprobe {
  	struct hlist_node hlist;

  	/* list of kprobes for multi-handler support */
  	struct list_head list;

  	/*count the number of times this probe was temporarily disarmed */
  	unsigned long nmissed;

  	/* location of the probe point */
  	kprobe_opcode_t *addr;

  	/* Allow user to indicate symbol name of the probe point */

  	const char *symbol_name;

  
  	/* Offset into the symbol */
  	unsigned int offset;

  	/* Called before addr is executed. */
  	kprobe_pre_handler_t pre_handler;
  
  	/* Called after addr is executed, unless... */
  	kprobe_post_handler_t post_handler;

  	/*
  	 * ... called if executing addr causes a fault (eg. page fault).
  	 * Return 1 if it handled fault, otherwise kernel will see it.
  	 */

  	kprobe_fault_handler_t fault_handler;

  	/*
  	 * ... called if breakpoint trap occurs in probe handler.
  	 * Return 1 if it handled break, otherwise kernel will see it.
  	 */

  	kprobe_break_handler_t break_handler;
  
  	/* Saved opcode (which has been replaced with breakpoint) */
  	kprobe_opcode_t opcode;
  
  	/* copy of the original instruction */
  	struct arch_specific_insn ainsn;

  	/*
  	 * Indicates various status flags.
  	 * Protected by kprobe_mutex after this kprobe is registered.
  	 */

  	u32 flags;

  };

  /* Kprobe status flags */
  #define KPROBE_FLAG_GONE	1 /* breakpoint has already gone */

  #define KPROBE_FLAG_DISABLED	2 /* probe is temporarily disabled */

  #define KPROBE_FLAG_OPTIMIZED	4 /*
  				   * probe is really optimized.
  				   * NOTE:
  				   * this flag is only for optimized_kprobe.
  				   */

  /* Has this kprobe gone ? */

  static inline int kprobe_gone(struct kprobe *p)
  {
  	return p->flags & KPROBE_FLAG_GONE;
  }

  /* Is this kprobe disabled ? */
  static inline int kprobe_disabled(struct kprobe *p)
  {
  	return p->flags & (KPROBE_FLAG_DISABLED | KPROBE_FLAG_GONE);
  }

  
  /* Is this kprobe really running optimized path ? */
  static inline int kprobe_optimized(struct kprobe *p)
  {
  	return p->flags & KPROBE_FLAG_OPTIMIZED;
  }

  /*
   * Special probe type that uses setjmp-longjmp type tricks to resume
   * execution at a specified entry with a matching prototype corresponding
   * to the probed function - a trick to enable arguments to become
   * accessible seamlessly by probe handling logic.
   * Note:
   * Because of the way compilers allocate stack space for local variables
   * etc upfront, regardless of sub-scopes within a function, this mirroring
   * principle currently works only for probes placed on function entry points.
   */
  struct jprobe {
  	struct kprobe kp;

  	void *entry;	/* probe handling code to jump to */

  };

  /* For backward compatibility with old code using JPROBE_ENTRY() */
  #define JPROBE_ENTRY(handler)	(handler)

  /*
   * Function-return probe -
   * Note:
   * User needs to provide a handler function, and initialize maxactive.
   * maxactive - The maximum number of instances of the probed function that
   * can be active concurrently.
   * nmissed - tracks the number of times the probed function's return was
   * ignored, due to maxactive being too low.
   *
   */
  struct kretprobe {
  	struct kprobe kp;
  	kretprobe_handler_t handler;

  	kretprobe_handler_t entry_handler;

  	int maxactive;
  	int nmissed;

  	size_t data_size;

  	struct hlist_head free_instances;

  	raw_spinlock_t lock;

  };
  
  struct kretprobe_instance {

  	struct hlist_node hlist;
  	struct kretprobe *rp;

  	kprobe_opcode_t *ret_addr;
  	struct task_struct *task;

  	char data[0];

  };

  struct kretprobe_blackpoint {
  	const char *name;
  	void *addr;
  };

  
  struct kprobe_blackpoint {
  	const char *name;
  	unsigned long start_addr;
  	unsigned long range;
  };

  #ifdef CONFIG_KPROBES
  DECLARE_PER_CPU(struct kprobe *, current_kprobe);
  DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);

  /*
   * For #ifdef avoidance:
   */
  static inline int kprobes_built_in(void)
  {
  	return 1;
  }

  #ifdef CONFIG_KRETPROBES
  extern void arch_prepare_kretprobe(struct kretprobe_instance *ri,
  				   struct pt_regs *regs);
  extern int arch_trampoline_kprobe(struct kprobe *p);
  #else /* CONFIG_KRETPROBES */
  static inline void arch_prepare_kretprobe(struct kretprobe *rp,
  					struct pt_regs *regs)
  {
  }
  static inline int arch_trampoline_kprobe(struct kprobe *p)
  {
  	return 0;
  }
  #endif /* CONFIG_KRETPROBES */

  extern struct kretprobe_blackpoint kretprobe_blacklist[];

  static inline void kretprobe_assert(struct kretprobe_instance *ri,
  	unsigned long orig_ret_address, unsigned long trampoline_address)
  {
  	if (!orig_ret_address || (orig_ret_address == trampoline_address)) {
  		printk("kretprobe BUG!: Processing kretprobe %p @ %p
  ",
  				ri->rp, ri->rp->kp.addr);
  		BUG();
  	}
  }

  #ifdef CONFIG_KPROBES_SANITY_TEST
  extern int init_test_probes(void);
  #else
  static inline int init_test_probes(void)
  {
  	return 0;
  }
  #endif /* CONFIG_KPROBES_SANITY_TEST */

  extern int arch_prepare_kprobe(struct kprobe *p);

  extern void arch_arm_kprobe(struct kprobe *p);
  extern void arch_disarm_kprobe(struct kprobe *p);

  extern int arch_init_kprobes(void);

  extern void show_registers(struct pt_regs *regs);

  extern kprobe_opcode_t *get_insn_slot(void);

  extern void free_insn_slot(kprobe_opcode_t *slot, int dirty);

  extern void kprobes_inc_nmissed_count(struct kprobe *p);

  #ifdef CONFIG_OPTPROBES
  /*
   * Internal structure for direct jump optimized probe
   */
  struct optimized_kprobe {
  	struct kprobe kp;
  	struct list_head list;	/* list for optimizing queue */
  	struct arch_optimized_insn optinsn;
  };
  
  /* Architecture dependent functions for direct jump optimization */
  extern int arch_prepared_optinsn(struct arch_optimized_insn *optinsn);
  extern int arch_check_optimized_kprobe(struct optimized_kprobe *op);
  extern int arch_prepare_optimized_kprobe(struct optimized_kprobe *op);
  extern void arch_remove_optimized_kprobe(struct optimized_kprobe *op);

  extern void arch_optimize_kprobes(struct list_head *oplist);

  extern void arch_unoptimize_kprobes(struct list_head *oplist,
  				    struct list_head *done_list);

  extern void arch_unoptimize_kprobe(struct optimized_kprobe *op);
  extern kprobe_opcode_t *get_optinsn_slot(void);
  extern void free_optinsn_slot(kprobe_opcode_t *slot, int dirty);
  extern int arch_within_optimized_kprobe(struct optimized_kprobe *op,
  					unsigned long addr);
  
  extern void opt_pre_handler(struct kprobe *p, struct pt_regs *regs);

  
  #ifdef CONFIG_SYSCTL
  extern int sysctl_kprobes_optimization;
  extern int proc_kprobes_optimization_handler(struct ctl_table *table,
  					     int write, void __user *buffer,
  					     size_t *length, loff_t *ppos);
  #endif

  #endif /* CONFIG_OPTPROBES */

  /* Get the kprobe at this addr (if any) - called with preemption disabled */

  struct kprobe *get_kprobe(void *addr);

  void kretprobe_hash_lock(struct task_struct *tsk,
  			 struct hlist_head **head, unsigned long *flags);
  void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags);

  struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk);

  /* kprobe_running() will just return the current_kprobe on this CPU */
  static inline struct kprobe *kprobe_running(void)
  {

  	return (__this_cpu_read(current_kprobe));

  }
  
  static inline void reset_current_kprobe(void)
  {

  	__this_cpu_write(current_kprobe, NULL);

  }
  
  static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void)
  {
  	return (&__get_cpu_var(kprobe_ctlblk));
  }

  int register_kprobe(struct kprobe *p);
  void unregister_kprobe(struct kprobe *p);

  int register_kprobes(struct kprobe **kps, int num);
  void unregister_kprobes(struct kprobe **kps, int num);

  int setjmp_pre_handler(struct kprobe *, struct pt_regs *);
  int longjmp_break_handler(struct kprobe *, struct pt_regs *);
  int register_jprobe(struct jprobe *p);
  void unregister_jprobe(struct jprobe *p);

  int register_jprobes(struct jprobe **jps, int num);
  void unregister_jprobes(struct jprobe **jps, int num);

  void jprobe_return(void);

  unsigned long arch_deref_entry_point(void *);

  int register_kretprobe(struct kretprobe *rp);
  void unregister_kretprobe(struct kretprobe *rp);

  int register_kretprobes(struct kretprobe **rps, int num);
  void unregister_kretprobes(struct kretprobe **rps, int num);

  void kprobe_flush_task(struct task_struct *tk);

  void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head);

  int disable_kprobe(struct kprobe *kp);
  int enable_kprobe(struct kprobe *kp);

  void dump_kprobe(struct kprobe *kp);

  #else /* !CONFIG_KPROBES: */

  static inline int kprobes_built_in(void)
  {
  	return 0;
  }
  static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
  {
  	return 0;
  }

  static inline struct kprobe *get_kprobe(void *addr)
  {
  	return NULL;
  }

  static inline struct kprobe *kprobe_running(void)

  {

  	return NULL;

  }
  static inline int register_kprobe(struct kprobe *p)
  {
  	return -ENOSYS;
  }

  static inline int register_kprobes(struct kprobe **kps, int num)
  {
  	return -ENOSYS;
  }

  static inline void unregister_kprobe(struct kprobe *p)
  {
  }

  static inline void unregister_kprobes(struct kprobe **kps, int num)
  {
  }

  static inline int register_jprobe(struct jprobe *p)
  {
  	return -ENOSYS;
  }

  static inline int register_jprobes(struct jprobe **jps, int num)
  {
  	return -ENOSYS;
  }

  static inline void unregister_jprobe(struct jprobe *p)
  {
  }

  static inline void unregister_jprobes(struct jprobe **jps, int num)
  {
  }

  static inline void jprobe_return(void)
  {
  }

  static inline int register_kretprobe(struct kretprobe *rp)
  {
  	return -ENOSYS;
  }

  static inline int register_kretprobes(struct kretprobe **rps, int num)
  {
  	return -ENOSYS;
  }

  static inline void unregister_kretprobe(struct kretprobe *rp)
  {
  }

  static inline void unregister_kretprobes(struct kretprobe **rps, int num)
  {
  }

  static inline void kprobe_flush_task(struct task_struct *tk)
  {
  }

  static inline int disable_kprobe(struct kprobe *kp)
  {
  	return -ENOSYS;
  }
  static inline int enable_kprobe(struct kprobe *kp)
  {
  	return -ENOSYS;
  }

  #endif /* CONFIG_KPROBES */

  static inline int disable_kretprobe(struct kretprobe *rp)
  {
  	return disable_kprobe(&rp->kp);
  }
  static inline int enable_kretprobe(struct kretprobe *rp)
  {
  	return enable_kprobe(&rp->kp);
  }
  static inline int disable_jprobe(struct jprobe *jp)
  {
  	return disable_kprobe(&jp->kp);
  }
  static inline int enable_jprobe(struct jprobe *jp)
  {
  	return enable_kprobe(&jp->kp);
  }

  #endif /* _LINUX_KPROBES_H */