1 #ifndef _LINUX_KPROBES_H
2 #define _LINUX_KPROBES_H
4 * Kernel Probes (KProbes)
5 * include/linux/kprobes.h
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
21 * Copyright (C) IBM Corporation, 2002, 2004
23 * 2002-Oct Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel
24 * Probes initial implementation ( includes suggestions from
26 * 2004-July Suparna Bhattacharya <suparna@in.ibm.com> added jumper probes
27 * interface to access function arguments.
28 * 2005-May Hien Nguyen <hien@us.ibm.com> and Jim Keniston
29 * <jkenisto@us.ibm.com> and Prasanna S Panchamukhi
30 * <prasanna@in.ibm.com> added function-return probes.
32 #include <linux/config.h>
33 #include <linux/list.h>
34 #include <linux/notifier.h>
35 #include <linux/smp.h>
36 #include <linux/percpu.h>
38 #include <asm/kprobes.h>
40 /* kprobe_status settings */
41 #define KPROBE_HIT_ACTIVE 0x00000001
42 #define KPROBE_HIT_SS 0x00000002
43 #define KPROBE_REENTER 0x00000004
44 #define KPROBE_HIT_SSDONE 0x00000008
46 /* Attach to insert probes on any functions which should be ignored*/
47 #define __kprobes __attribute__((__section__(".kprobes.text")))
52 struct kretprobe_instance;
53 typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *);
54 typedef int (*kprobe_break_handler_t) (struct kprobe *, struct pt_regs *);
55 typedef void (*kprobe_post_handler_t) (struct kprobe *, struct pt_regs *,
57 typedef int (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *,
59 typedef int (*kretprobe_handler_t) (struct kretprobe_instance *,
63 struct hlist_node hlist;
65 /* list of kprobes for multi-handler support */
66 struct list_head list;
68 /*count the number of times this probe was temporarily disarmed */
69 unsigned long nmissed;
71 /* location of the probe point */
72 kprobe_opcode_t *addr;
74 /* Called before addr is executed. */
75 kprobe_pre_handler_t pre_handler;
77 /* Called after addr is executed, unless... */
78 kprobe_post_handler_t post_handler;
80 /* ... called if executing addr causes a fault (eg. page fault).
81 * Return 1 if it handled fault, otherwise kernel will see it. */
82 kprobe_fault_handler_t fault_handler;
84 /* ... called if breakpoint trap occurs in probe handler.
85 * Return 1 if it handled break, otherwise kernel will see it. */
86 kprobe_break_handler_t break_handler;
88 /* Saved opcode (which has been replaced with breakpoint) */
89 kprobe_opcode_t opcode;
91 /* copy of the original instruction */
92 struct arch_specific_insn ainsn;
96 * Special probe type that uses setjmp-longjmp type tricks to resume
97 * execution at a specified entry with a matching prototype corresponding
98 * to the probed function - a trick to enable arguments to become
99 * accessible seamlessly by probe handling logic.
101 * Because of the way compilers allocate stack space for local variables
102 * etc upfront, regardless of sub-scopes within a function, this mirroring
103 * principle currently works only for probes placed on function entry points.
107 kprobe_opcode_t *entry; /* probe handling code to jump to */
110 DECLARE_PER_CPU(struct kprobe *, current_kprobe);
111 DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
113 #ifdef ARCH_SUPPORTS_KRETPROBES
114 extern void arch_prepare_kretprobe(struct kretprobe *rp, struct pt_regs *regs);
115 #else /* ARCH_SUPPORTS_KRETPROBES */
116 static inline void arch_prepare_kretprobe(struct kretprobe *rp,
117 struct pt_regs *regs)
120 #endif /* ARCH_SUPPORTS_KRETPROBES */
122 * Function-return probe -
124 * User needs to provide a handler function, and initialize maxactive.
125 * maxactive - The maximum number of instances of the probed function that
126 * can be active concurrently.
127 * nmissed - tracks the number of times the probed function's return was
128 * ignored, due to maxactive being too low.
133 kretprobe_handler_t handler;
136 struct hlist_head free_instances;
137 struct hlist_head used_instances;
140 struct kretprobe_instance {
141 struct hlist_node uflist; /* either on free list or used list */
142 struct hlist_node hlist;
143 struct kretprobe *rp;
144 kprobe_opcode_t *ret_addr;
145 struct task_struct *task;
148 #ifdef CONFIG_KPROBES
149 /* Locks kprobe: irq must be disabled */
150 void lock_kprobes(void);
151 void unlock_kprobes(void);
153 extern int arch_prepare_kprobe(struct kprobe *p);
154 extern void arch_copy_kprobe(struct kprobe *p);
155 extern void arch_arm_kprobe(struct kprobe *p);
156 extern void arch_disarm_kprobe(struct kprobe *p);
157 extern void arch_remove_kprobe(struct kprobe *p);
158 extern int arch_init_kprobes(void);
159 extern void show_registers(struct pt_regs *regs);
160 extern kprobe_opcode_t *get_insn_slot(void);
161 extern void free_insn_slot(kprobe_opcode_t *slot);
163 /* Get the kprobe at this addr (if any). Must have called lock_kprobes */
164 struct kprobe *get_kprobe(void *addr);
165 struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk);
167 /* kprobe_running() will just return the current_kprobe on this CPU */
168 static inline struct kprobe *kprobe_running(void)
170 return (__get_cpu_var(current_kprobe));
173 static inline void reset_current_kprobe(void)
175 __get_cpu_var(current_kprobe) = NULL;
178 static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void)
180 return (&__get_cpu_var(kprobe_ctlblk));
183 int register_kprobe(struct kprobe *p);
184 void unregister_kprobe(struct kprobe *p);
185 int setjmp_pre_handler(struct kprobe *, struct pt_regs *);
186 int longjmp_break_handler(struct kprobe *, struct pt_regs *);
187 int register_jprobe(struct jprobe *p);
188 void unregister_jprobe(struct jprobe *p);
189 void jprobe_return(void);
191 int register_kretprobe(struct kretprobe *rp);
192 void unregister_kretprobe(struct kretprobe *rp);
194 struct kretprobe_instance *get_free_rp_inst(struct kretprobe *rp);
195 void add_rp_inst(struct kretprobe_instance *ri);
196 void kprobe_flush_task(struct task_struct *tk);
197 void recycle_rp_inst(struct kretprobe_instance *ri);
198 #else /* CONFIG_KPROBES */
199 static inline struct kprobe *kprobe_running(void)
203 static inline int register_kprobe(struct kprobe *p)
207 static inline void unregister_kprobe(struct kprobe *p)
210 static inline int register_jprobe(struct jprobe *p)
214 static inline void unregister_jprobe(struct jprobe *p)
217 static inline void jprobe_return(void)
220 static inline int register_kretprobe(struct kretprobe *rp)
224 static inline void unregister_kretprobe(struct kretprobe *rp)
227 static inline void kprobe_flush_task(struct task_struct *tk)
230 #endif /* CONFIG_KPROBES */
231 #endif /* _LINUX_KPROBES_H */