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#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/config.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 <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")))
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;
/* 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;
};
/*
* 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;
kprobe_opcode_t *entry; /* probe handling code to jump to */
};
DECLARE_PER_CPU(struct kprobe *, current_kprobe);
DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
#ifdef ARCH_SUPPORTS_KRETPROBES
extern void arch_prepare_kretprobe(struct kretprobe *rp, struct pt_regs *regs);
#else /* ARCH_SUPPORTS_KRETPROBES */
static inline void arch_prepare_kretprobe(struct kretprobe *rp,
struct pt_regs *regs)
{
}
#endif /* ARCH_SUPPORTS_KRETPROBES */
/*
* 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;
int maxactive;
int nmissed;
struct hlist_head free_instances;
struct hlist_head used_instances;
};
struct kretprobe_instance {
struct hlist_node uflist; /* either on free list or used list */
struct hlist_node hlist;
struct kretprobe *rp;
kprobe_opcode_t *ret_addr;
struct task_struct *task;
};
#ifdef CONFIG_KPROBES
extern spinlock_t kretprobe_lock;
extern int arch_prepare_kprobe(struct kprobe *p);
extern void arch_copy_kprobe(struct kprobe *p);
extern void arch_arm_kprobe(struct kprobe *p);
extern void arch_disarm_kprobe(struct kprobe *p);
extern void arch_remove_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);
/* Get the kprobe at this addr (if any) - called under a rcu_read_lock() */
struct kprobe *get_kprobe(void *addr);
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 (__get_cpu_var(current_kprobe));
}
static inline void reset_current_kprobe(void)
{
__get_cpu_var(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 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);
void jprobe_return(void);
int register_kretprobe(struct kretprobe *rp);
void unregister_kretprobe(struct kretprobe *rp);
struct kretprobe_instance *get_free_rp_inst(struct kretprobe *rp);
void add_rp_inst(struct kretprobe_instance *ri);
void kprobe_flush_task(struct task_struct *tk);
void recycle_rp_inst(struct kretprobe_instance *ri);
#else /* CONFIG_KPROBES */
static inline struct kprobe *kprobe_running(void)
{
return NULL;
}
static inline int register_kprobe(struct kprobe *p)
{
return -ENOSYS;
}
static inline void unregister_kprobe(struct kprobe *p)
{
}
static inline int register_jprobe(struct jprobe *p)
{
return -ENOSYS;
}
static inline void unregister_jprobe(struct jprobe *p)
{
}
static inline void jprobe_return(void)
{
}
static inline int register_kretprobe(struct kretprobe *rp)
{
return -ENOSYS;
}
static inline void unregister_kretprobe(struct kretprobe *rp)
{
}
static inline void kprobe_flush_task(struct task_struct *tk)
{
}
#endif /* CONFIG_KPROBES */
#endif /* _LINUX_KPROBES_H */
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