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>
37 #include <asm/kprobes.h>
42 struct kretprobe_instance;
43 typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *);
44 typedef int (*kprobe_break_handler_t) (struct kprobe *, struct pt_regs *);
45 typedef void (*kprobe_post_handler_t) (struct kprobe *, struct pt_regs *,
47 typedef int (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *,
49 typedef int (*kretprobe_handler_t) (struct kretprobe_instance *,
53 struct hlist_node hlist;
55 /* list of kprobes for multi-handler support */
56 struct list_head list;
58 /* location of the probe point */
59 kprobe_opcode_t *addr;
61 /* Called before addr is executed. */
62 kprobe_pre_handler_t pre_handler;
64 /* Called after addr is executed, unless... */
65 kprobe_post_handler_t post_handler;
67 /* ... called if executing addr causes a fault (eg. page fault).
68 * Return 1 if it handled fault, otherwise kernel will see it. */
69 kprobe_fault_handler_t fault_handler;
71 /* ... called if breakpoint trap occurs in probe handler.
72 * Return 1 if it handled break, otherwise kernel will see it. */
73 kprobe_break_handler_t break_handler;
75 /* Saved opcode (which has been replaced with breakpoint) */
76 kprobe_opcode_t opcode;
78 /* copy of the original instruction */
79 struct arch_specific_insn ainsn;
83 * Special probe type that uses setjmp-longjmp type tricks to resume
84 * execution at a specified entry with a matching prototype corresponding
85 * to the probed function - a trick to enable arguments to become
86 * accessible seamlessly by probe handling logic.
88 * Because of the way compilers allocate stack space for local variables
89 * etc upfront, regardless of sub-scopes within a function, this mirroring
90 * principle currently works only for probes placed on function entry points.
94 kprobe_opcode_t *entry; /* probe handling code to jump to */
97 #ifdef ARCH_SUPPORTS_KRETPROBES
98 extern int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs);
99 extern void trampoline_post_handler(struct kprobe *p, struct pt_regs *regs,
100 unsigned long flags);
101 extern struct task_struct *arch_get_kprobe_task(void *ptr);
102 extern void arch_prepare_kretprobe(struct kretprobe *rp, struct pt_regs *regs);
103 extern void arch_kprobe_flush_task(struct task_struct *tk);
104 #else /* ARCH_SUPPORTS_KRETPROBES */
105 static inline void kretprobe_trampoline(void)
108 static inline int trampoline_probe_handler(struct kprobe *p,
109 struct pt_regs *regs)
113 static inline void trampoline_post_handler(struct kprobe *p,
114 struct pt_regs *regs, unsigned long flags)
117 static inline void arch_prepare_kretprobe(struct kretprobe *rp,
118 struct pt_regs *regs)
121 static inline void arch_kprobe_flush_task(struct task_struct *tk)
124 #define arch_get_kprobe_task(ptr) ((struct task_struct *)NULL)
125 #endif /* ARCH_SUPPORTS_KRETPROBES */
127 * Function-return probe -
129 * User needs to provide a handler function, and initialize maxactive.
130 * maxactive - The maximum number of instances of the probed function that
131 * can be active concurrently.
132 * nmissed - tracks the number of times the probed function's return was
133 * ignored, due to maxactive being too low.
138 kretprobe_handler_t handler;
141 struct hlist_head free_instances;
142 struct hlist_head used_instances;
145 struct kretprobe_instance {
146 struct hlist_node uflist; /* either on free list or used list */
147 struct hlist_node hlist;
148 struct kretprobe *rp;
153 #ifdef CONFIG_KPROBES
154 /* Locks kprobe: irq must be disabled */
155 void lock_kprobes(void);
156 void unlock_kprobes(void);
158 /* kprobe running now on this CPU? */
159 static inline int kprobe_running(void)
161 extern unsigned int kprobe_cpu;
162 return kprobe_cpu == smp_processor_id();
165 extern int arch_prepare_kprobe(struct kprobe *p);
166 extern void arch_copy_kprobe(struct kprobe *p);
167 extern void arch_arm_kprobe(struct kprobe *p);
168 extern void arch_disarm_kprobe(struct kprobe *p);
169 extern void arch_remove_kprobe(struct kprobe *p);
170 extern void show_registers(struct pt_regs *regs);
172 /* Get the kprobe at this addr (if any). Must have called lock_kprobes */
173 struct kprobe *get_kprobe(void *addr);
174 struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk);
176 int register_kprobe(struct kprobe *p);
177 void unregister_kprobe(struct kprobe *p);
178 int setjmp_pre_handler(struct kprobe *, struct pt_regs *);
179 int longjmp_break_handler(struct kprobe *, struct pt_regs *);
180 int register_jprobe(struct jprobe *p);
181 void unregister_jprobe(struct jprobe *p);
182 void jprobe_return(void);
184 int register_kretprobe(struct kretprobe *rp);
185 void unregister_kretprobe(struct kretprobe *rp);
187 struct kretprobe_instance *get_free_rp_inst(struct kretprobe *rp);
188 struct kretprobe_instance *get_rp_inst(void *sara);
189 struct kretprobe_instance *get_rp_inst_tsk(struct task_struct *tk);
190 void add_rp_inst(struct kretprobe_instance *ri);
191 void kprobe_flush_task(struct task_struct *tk);
192 void recycle_rp_inst(struct kretprobe_instance *ri);
193 #else /* CONFIG_KPROBES */
194 static inline int kprobe_running(void)
198 static inline int register_kprobe(struct kprobe *p)
202 static inline void unregister_kprobe(struct kprobe *p)
205 static inline int register_jprobe(struct jprobe *p)
209 static inline void unregister_jprobe(struct jprobe *p)
212 static inline void jprobe_return(void)
215 static inline int register_kretprobe(struct kretprobe *rp)
219 static inline void unregister_kretprobe(struct kretprobe *rp)
222 static inline void kprobe_flush_task(struct task_struct *tk)
225 #endif /* CONFIG_KPROBES */
226 #endif /* _LINUX_KPROBES_H */