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/linkage.h>
33 #include <linux/list.h>
34 #include <linux/notifier.h>
35 #include <linux/smp.h>
36 #include <linux/percpu.h>
37 #include <linux/spinlock.h>
38 #include <linux/rcupdate.h>
39 #include <linux/mutex.h>
42 #include <asm/kprobes.h>
44 /* kprobe_status settings */
45 #define KPROBE_HIT_ACTIVE 0x00000001
46 #define KPROBE_HIT_SS 0x00000002
47 #define KPROBE_REENTER 0x00000004
48 #define KPROBE_HIT_SSDONE 0x00000008
50 /* Attach to insert probes on any functions which should be ignored*/
51 #define __kprobes __attribute__((__section__(".kprobes.text"))) notrace
52 #else /* CONFIG_KPROBES */
53 typedef int kprobe_opcode_t;
54 struct arch_specific_insn {
57 #define __kprobes notrace
58 #endif /* CONFIG_KPROBES */
63 struct kretprobe_instance;
64 typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *);
65 typedef int (*kprobe_break_handler_t) (struct kprobe *, struct pt_regs *);
66 typedef void (*kprobe_post_handler_t) (struct kprobe *, struct pt_regs *,
68 typedef int (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *,
70 typedef int (*kretprobe_handler_t) (struct kretprobe_instance *,
74 struct hlist_node hlist;
76 /* list of kprobes for multi-handler support */
77 struct list_head list;
79 /*count the number of times this probe was temporarily disarmed */
80 unsigned long nmissed;
82 /* location of the probe point */
83 kprobe_opcode_t *addr;
85 /* Allow user to indicate symbol name of the probe point */
86 const char *symbol_name;
88 /* Offset into the symbol */
91 /* Called before addr is executed. */
92 kprobe_pre_handler_t pre_handler;
94 /* Called after addr is executed, unless... */
95 kprobe_post_handler_t post_handler;
98 * ... called if executing addr causes a fault (eg. page fault).
99 * Return 1 if it handled fault, otherwise kernel will see it.
101 kprobe_fault_handler_t fault_handler;
104 * ... called if breakpoint trap occurs in probe handler.
105 * Return 1 if it handled break, otherwise kernel will see it.
107 kprobe_break_handler_t break_handler;
109 /* Saved opcode (which has been replaced with breakpoint) */
110 kprobe_opcode_t opcode;
112 /* copy of the original instruction */
113 struct arch_specific_insn ainsn;
115 /* Indicates various status flags. Protected by kprobe_mutex. */
119 /* Kprobe status flags */
120 #define KPROBE_FLAG_GONE 1 /* breakpoint has already gone */
122 static inline int kprobe_gone(struct kprobe *p)
124 return p->flags & KPROBE_FLAG_GONE;
128 * Special probe type that uses setjmp-longjmp type tricks to resume
129 * execution at a specified entry with a matching prototype corresponding
130 * to the probed function - a trick to enable arguments to become
131 * accessible seamlessly by probe handling logic.
133 * Because of the way compilers allocate stack space for local variables
134 * etc upfront, regardless of sub-scopes within a function, this mirroring
135 * principle currently works only for probes placed on function entry points.
139 void *entry; /* probe handling code to jump to */
142 /* For backward compatibility with old code using JPROBE_ENTRY() */
143 #define JPROBE_ENTRY(handler) (handler)
146 * Function-return probe -
148 * User needs to provide a handler function, and initialize maxactive.
149 * maxactive - The maximum number of instances of the probed function that
150 * can be active concurrently.
151 * nmissed - tracks the number of times the probed function's return was
152 * ignored, due to maxactive being too low.
157 kretprobe_handler_t handler;
158 kretprobe_handler_t entry_handler;
162 struct hlist_head free_instances;
166 struct kretprobe_instance {
167 struct hlist_node hlist;
168 struct kretprobe *rp;
169 kprobe_opcode_t *ret_addr;
170 struct task_struct *task;
174 struct kretprobe_blackpoint {
179 struct kprobe_blackpoint {
181 unsigned long start_addr;
185 #ifdef CONFIG_KPROBES
186 DECLARE_PER_CPU(struct kprobe *, current_kprobe);
187 DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
190 * For #ifdef avoidance:
192 static inline int kprobes_built_in(void)
197 #ifdef CONFIG_KRETPROBES
198 extern void arch_prepare_kretprobe(struct kretprobe_instance *ri,
199 struct pt_regs *regs);
200 extern int arch_trampoline_kprobe(struct kprobe *p);
201 #else /* CONFIG_KRETPROBES */
202 static inline void arch_prepare_kretprobe(struct kretprobe *rp,
203 struct pt_regs *regs)
206 static inline int arch_trampoline_kprobe(struct kprobe *p)
210 #endif /* CONFIG_KRETPROBES */
212 extern struct kretprobe_blackpoint kretprobe_blacklist[];
214 static inline void kretprobe_assert(struct kretprobe_instance *ri,
215 unsigned long orig_ret_address, unsigned long trampoline_address)
217 if (!orig_ret_address || (orig_ret_address == trampoline_address)) {
218 printk("kretprobe BUG!: Processing kretprobe %p @ %p\n",
219 ri->rp, ri->rp->kp.addr);
224 #ifdef CONFIG_KPROBES_SANITY_TEST
225 extern int init_test_probes(void);
227 static inline int init_test_probes(void)
231 #endif /* CONFIG_KPROBES_SANITY_TEST */
233 extern int arch_prepare_kprobe(struct kprobe *p);
234 extern void arch_arm_kprobe(struct kprobe *p);
235 extern void arch_disarm_kprobe(struct kprobe *p);
236 extern int arch_init_kprobes(void);
237 extern void show_registers(struct pt_regs *regs);
238 extern kprobe_opcode_t *get_insn_slot(void);
239 extern void free_insn_slot(kprobe_opcode_t *slot, int dirty);
240 extern void kprobes_inc_nmissed_count(struct kprobe *p);
242 /* Get the kprobe at this addr (if any) - called with preemption disabled */
243 struct kprobe *get_kprobe(void *addr);
244 void kretprobe_hash_lock(struct task_struct *tsk,
245 struct hlist_head **head, unsigned long *flags);
246 void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags);
247 struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk);
249 /* kprobe_running() will just return the current_kprobe on this CPU */
250 static inline struct kprobe *kprobe_running(void)
252 return (__get_cpu_var(current_kprobe));
255 static inline void reset_current_kprobe(void)
257 __get_cpu_var(current_kprobe) = NULL;
260 static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void)
262 return (&__get_cpu_var(kprobe_ctlblk));
265 int register_kprobe(struct kprobe *p);
266 void unregister_kprobe(struct kprobe *p);
267 int register_kprobes(struct kprobe **kps, int num);
268 void unregister_kprobes(struct kprobe **kps, int num);
269 int setjmp_pre_handler(struct kprobe *, struct pt_regs *);
270 int longjmp_break_handler(struct kprobe *, struct pt_regs *);
271 int register_jprobe(struct jprobe *p);
272 void unregister_jprobe(struct jprobe *p);
273 int register_jprobes(struct jprobe **jps, int num);
274 void unregister_jprobes(struct jprobe **jps, int num);
275 void jprobe_return(void);
276 unsigned long arch_deref_entry_point(void *);
278 int register_kretprobe(struct kretprobe *rp);
279 void unregister_kretprobe(struct kretprobe *rp);
280 int register_kretprobes(struct kretprobe **rps, int num);
281 void unregister_kretprobes(struct kretprobe **rps, int num);
283 void kprobe_flush_task(struct task_struct *tk);
284 void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head);
286 #else /* !CONFIG_KPROBES: */
288 static inline int kprobes_built_in(void)
292 static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
296 static inline struct kprobe *get_kprobe(void *addr)
300 static inline struct kprobe *kprobe_running(void)
304 static inline int register_kprobe(struct kprobe *p)
308 static inline int register_kprobes(struct kprobe **kps, int num)
312 static inline void unregister_kprobe(struct kprobe *p)
315 static inline void unregister_kprobes(struct kprobe **kps, int num)
318 static inline int register_jprobe(struct jprobe *p)
322 static inline int register_jprobes(struct jprobe **jps, int num)
326 static inline void unregister_jprobe(struct jprobe *p)
329 static inline void unregister_jprobes(struct jprobe **jps, int num)
332 static inline void jprobe_return(void)
335 static inline int register_kretprobe(struct kretprobe *rp)
339 static inline int register_kretprobes(struct kretprobe **rps, int num)
343 static inline void unregister_kretprobe(struct kretprobe *rp)
346 static inline void unregister_kretprobes(struct kretprobe **rps, int num)
349 static inline void kprobe_flush_task(struct task_struct *tk)
352 #endif /* CONFIG_KPROBES */
353 #endif /* _LINUX_KPROBES_H */