]>
Commit | Line | Data |
---|---|---|
d39f5450 CS |
1 | /* |
2 | * Kernel probes (kprobes) for SuperH | |
3 | * | |
4 | * Copyright (C) 2007 Chris Smith <chris.smith@st.com> | |
5 | * Copyright (C) 2006 Lineo Solutions, Inc. | |
6 | * | |
7 | * This file is subject to the terms and conditions of the GNU General Public | |
8 | * License. See the file "COPYING" in the main directory of this archive | |
9 | * for more details. | |
10 | */ | |
11 | #include <linux/kprobes.h> | |
12 | #include <linux/module.h> | |
13 | #include <linux/ptrace.h> | |
14 | #include <linux/preempt.h> | |
15 | #include <linux/kdebug.h> | |
16 | #include <asm/cacheflush.h> | |
17 | #include <asm/uaccess.h> | |
18 | ||
19 | DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL; | |
20 | DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); | |
21 | ||
22 | static struct kprobe saved_current_opcode; | |
23 | static struct kprobe saved_next_opcode; | |
24 | static struct kprobe saved_next_opcode2; | |
25 | ||
26 | #define OPCODE_JMP(x) (((x) & 0xF0FF) == 0x402b) | |
27 | #define OPCODE_JSR(x) (((x) & 0xF0FF) == 0x400b) | |
28 | #define OPCODE_BRA(x) (((x) & 0xF000) == 0xa000) | |
29 | #define OPCODE_BRAF(x) (((x) & 0xF0FF) == 0x0023) | |
30 | #define OPCODE_BSR(x) (((x) & 0xF000) == 0xb000) | |
31 | #define OPCODE_BSRF(x) (((x) & 0xF0FF) == 0x0003) | |
32 | ||
33 | #define OPCODE_BF_S(x) (((x) & 0xFF00) == 0x8f00) | |
34 | #define OPCODE_BT_S(x) (((x) & 0xFF00) == 0x8d00) | |
35 | ||
36 | #define OPCODE_BF(x) (((x) & 0xFF00) == 0x8b00) | |
37 | #define OPCODE_BT(x) (((x) & 0xFF00) == 0x8900) | |
38 | ||
39 | #define OPCODE_RTS(x) (((x) & 0x000F) == 0x000b) | |
40 | #define OPCODE_RTE(x) (((x) & 0xFFFF) == 0x002b) | |
41 | ||
42 | int __kprobes arch_prepare_kprobe(struct kprobe *p) | |
43 | { | |
44 | kprobe_opcode_t opcode = *(kprobe_opcode_t *) (p->addr); | |
45 | ||
46 | if (OPCODE_RTE(opcode)) | |
47 | return -EFAULT; /* Bad breakpoint */ | |
48 | ||
49 | p->opcode = opcode; | |
50 | ||
51 | return 0; | |
52 | } | |
53 | ||
54 | void __kprobes arch_copy_kprobe(struct kprobe *p) | |
55 | { | |
56 | memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t)); | |
57 | p->opcode = *p->addr; | |
58 | } | |
59 | ||
60 | void __kprobes arch_arm_kprobe(struct kprobe *p) | |
61 | { | |
62 | *p->addr = BREAKPOINT_INSTRUCTION; | |
63 | flush_icache_range((unsigned long)p->addr, | |
64 | (unsigned long)p->addr + sizeof(kprobe_opcode_t)); | |
65 | } | |
66 | ||
67 | void __kprobes arch_disarm_kprobe(struct kprobe *p) | |
68 | { | |
69 | *p->addr = p->opcode; | |
70 | flush_icache_range((unsigned long)p->addr, | |
71 | (unsigned long)p->addr + sizeof(kprobe_opcode_t)); | |
72 | } | |
73 | ||
74 | int __kprobes arch_trampoline_kprobe(struct kprobe *p) | |
75 | { | |
76 | if (*p->addr == BREAKPOINT_INSTRUCTION) | |
77 | return 1; | |
78 | ||
79 | return 0; | |
80 | } | |
81 | ||
82 | /** | |
83 | * If an illegal slot instruction exception occurs for an address | |
84 | * containing a kprobe, remove the probe. | |
85 | * | |
86 | * Returns 0 if the exception was handled successfully, 1 otherwise. | |
87 | */ | |
88 | int __kprobes kprobe_handle_illslot(unsigned long pc) | |
89 | { | |
90 | struct kprobe *p = get_kprobe((kprobe_opcode_t *) pc + 1); | |
91 | ||
92 | if (p != NULL) { | |
93 | printk("Warning: removing kprobe from delay slot: 0x%.8x\n", | |
94 | (unsigned int)pc + 2); | |
95 | unregister_kprobe(p); | |
96 | return 0; | |
97 | } | |
98 | ||
99 | return 1; | |
100 | } | |
101 | ||
102 | void __kprobes arch_remove_kprobe(struct kprobe *p) | |
103 | { | |
104 | if (saved_next_opcode.addr != 0x0) { | |
105 | arch_disarm_kprobe(p); | |
106 | arch_disarm_kprobe(&saved_next_opcode); | |
107 | saved_next_opcode.addr = 0x0; | |
108 | saved_next_opcode.opcode = 0x0; | |
109 | ||
110 | if (saved_next_opcode2.addr != 0x0) { | |
111 | arch_disarm_kprobe(&saved_next_opcode2); | |
112 | saved_next_opcode2.addr = 0x0; | |
113 | saved_next_opcode2.opcode = 0x0; | |
114 | } | |
115 | } | |
116 | } | |
117 | ||
118 | static inline void save_previous_kprobe(struct kprobe_ctlblk *kcb) | |
119 | { | |
120 | kcb->prev_kprobe.kp = kprobe_running(); | |
121 | kcb->prev_kprobe.status = kcb->kprobe_status; | |
122 | } | |
123 | ||
124 | static inline void restore_previous_kprobe(struct kprobe_ctlblk *kcb) | |
125 | { | |
126 | __get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp; | |
127 | kcb->kprobe_status = kcb->prev_kprobe.status; | |
128 | } | |
129 | ||
130 | static inline void set_current_kprobe(struct kprobe *p, struct pt_regs *regs, | |
131 | struct kprobe_ctlblk *kcb) | |
132 | { | |
133 | __get_cpu_var(current_kprobe) = p; | |
134 | } | |
135 | ||
136 | /* | |
137 | * Singlestep is implemented by disabling the current kprobe and setting one | |
138 | * on the next instruction, following branches. Two probes are set if the | |
139 | * branch is conditional. | |
140 | */ | |
141 | static inline void prepare_singlestep(struct kprobe *p, struct pt_regs *regs) | |
142 | { | |
143 | kprobe_opcode_t *addr = NULL; | |
144 | saved_current_opcode.addr = (kprobe_opcode_t *) (regs->pc); | |
145 | addr = saved_current_opcode.addr; | |
146 | ||
147 | if (p != NULL) { | |
148 | arch_disarm_kprobe(p); | |
149 | ||
150 | if (OPCODE_JSR(p->opcode) || OPCODE_JMP(p->opcode)) { | |
151 | unsigned int reg_nr = ((p->opcode >> 8) & 0x000F); | |
152 | saved_next_opcode.addr = | |
153 | (kprobe_opcode_t *) regs->regs[reg_nr]; | |
154 | } else if (OPCODE_BRA(p->opcode) || OPCODE_BSR(p->opcode)) { | |
155 | unsigned long disp = (p->opcode & 0x0FFF); | |
156 | saved_next_opcode.addr = | |
157 | (kprobe_opcode_t *) (regs->pc + 4 + disp * 2); | |
158 | ||
159 | } else if (OPCODE_BRAF(p->opcode) || OPCODE_BSRF(p->opcode)) { | |
160 | unsigned int reg_nr = ((p->opcode >> 8) & 0x000F); | |
161 | saved_next_opcode.addr = | |
162 | (kprobe_opcode_t *) (regs->pc + 4 + | |
163 | regs->regs[reg_nr]); | |
164 | ||
165 | } else if (OPCODE_RTS(p->opcode)) { | |
166 | saved_next_opcode.addr = (kprobe_opcode_t *) regs->pr; | |
167 | ||
168 | } else if (OPCODE_BF(p->opcode) || OPCODE_BT(p->opcode)) { | |
169 | unsigned long disp = (p->opcode & 0x00FF); | |
170 | /* case 1 */ | |
171 | saved_next_opcode.addr = p->addr + 1; | |
172 | /* case 2 */ | |
173 | saved_next_opcode2.addr = | |
174 | (kprobe_opcode_t *) (regs->pc + 4 + disp * 2); | |
175 | saved_next_opcode2.opcode = *(saved_next_opcode2.addr); | |
176 | arch_arm_kprobe(&saved_next_opcode2); | |
177 | ||
178 | } else if (OPCODE_BF_S(p->opcode) || OPCODE_BT_S(p->opcode)) { | |
179 | unsigned long disp = (p->opcode & 0x00FF); | |
180 | /* case 1 */ | |
181 | saved_next_opcode.addr = p->addr + 2; | |
182 | /* case 2 */ | |
183 | saved_next_opcode2.addr = | |
184 | (kprobe_opcode_t *) (regs->pc + 4 + disp * 2); | |
185 | saved_next_opcode2.opcode = *(saved_next_opcode2.addr); | |
186 | arch_arm_kprobe(&saved_next_opcode2); | |
187 | ||
188 | } else { | |
189 | saved_next_opcode.addr = p->addr + 1; | |
190 | } | |
191 | ||
192 | saved_next_opcode.opcode = *(saved_next_opcode.addr); | |
193 | arch_arm_kprobe(&saved_next_opcode); | |
194 | } | |
195 | } | |
196 | ||
197 | /* Called with kretprobe_lock held */ | |
198 | void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, | |
199 | struct pt_regs *regs) | |
200 | { | |
201 | ri->ret_addr = (kprobe_opcode_t *) regs->pr; | |
202 | ||
203 | /* Replace the return addr with trampoline addr */ | |
204 | regs->pr = (unsigned long)kretprobe_trampoline; | |
205 | } | |
206 | ||
207 | static int __kprobes kprobe_handler(struct pt_regs *regs) | |
208 | { | |
209 | struct kprobe *p; | |
210 | int ret = 0; | |
211 | kprobe_opcode_t *addr = NULL; | |
212 | struct kprobe_ctlblk *kcb; | |
213 | ||
214 | /* | |
215 | * We don't want to be preempted for the entire | |
216 | * duration of kprobe processing | |
217 | */ | |
218 | preempt_disable(); | |
219 | kcb = get_kprobe_ctlblk(); | |
220 | ||
221 | addr = (kprobe_opcode_t *) (regs->pc); | |
222 | ||
223 | /* Check we're not actually recursing */ | |
224 | if (kprobe_running()) { | |
225 | p = get_kprobe(addr); | |
226 | if (p) { | |
227 | if (kcb->kprobe_status == KPROBE_HIT_SS && | |
228 | *p->ainsn.insn == BREAKPOINT_INSTRUCTION) { | |
229 | goto no_kprobe; | |
230 | } | |
231 | /* We have reentered the kprobe_handler(), since | |
232 | * another probe was hit while within the handler. | |
233 | * We here save the original kprobes variables and | |
234 | * just single step on the instruction of the new probe | |
235 | * without calling any user handlers. | |
236 | */ | |
237 | save_previous_kprobe(kcb); | |
238 | set_current_kprobe(p, regs, kcb); | |
239 | kprobes_inc_nmissed_count(p); | |
240 | prepare_singlestep(p, regs); | |
241 | kcb->kprobe_status = KPROBE_REENTER; | |
242 | return 1; | |
243 | } else { | |
244 | p = __get_cpu_var(current_kprobe); | |
245 | if (p->break_handler && p->break_handler(p, regs)) { | |
246 | goto ss_probe; | |
247 | } | |
248 | } | |
249 | goto no_kprobe; | |
250 | } | |
251 | ||
252 | p = get_kprobe(addr); | |
253 | if (!p) { | |
254 | /* Not one of ours: let kernel handle it */ | |
255 | goto no_kprobe; | |
256 | } | |
257 | ||
258 | set_current_kprobe(p, regs, kcb); | |
259 | kcb->kprobe_status = KPROBE_HIT_ACTIVE; | |
260 | ||
261 | if (p->pre_handler && p->pre_handler(p, regs)) | |
262 | /* handler has already set things up, so skip ss setup */ | |
263 | return 1; | |
264 | ||
265 | ss_probe: | |
266 | prepare_singlestep(p, regs); | |
267 | kcb->kprobe_status = KPROBE_HIT_SS; | |
268 | return 1; | |
269 | ||
270 | no_kprobe: | |
271 | preempt_enable_no_resched(); | |
272 | return ret; | |
273 | } | |
274 | ||
275 | /* | |
276 | * For function-return probes, init_kprobes() establishes a probepoint | |
277 | * here. When a retprobed function returns, this probe is hit and | |
278 | * trampoline_probe_handler() runs, calling the kretprobe's handler. | |
279 | */ | |
e7cb016e | 280 | static void __used kretprobe_trampoline_holder(void) |
d39f5450 CS |
281 | { |
282 | asm volatile ("kretprobe_trampoline: \n" "nop\n"); | |
283 | } | |
284 | ||
285 | /* | |
286 | * Called when we hit the probe point at kretprobe_trampoline | |
287 | */ | |
288 | int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) | |
289 | { | |
290 | struct kretprobe_instance *ri = NULL; | |
291 | struct hlist_head *head, empty_rp; | |
292 | struct hlist_node *node, *tmp; | |
293 | unsigned long flags, orig_ret_address = 0; | |
294 | unsigned long trampoline_address = (unsigned long)&kretprobe_trampoline; | |
295 | ||
296 | INIT_HLIST_HEAD(&empty_rp); | |
297 | kretprobe_hash_lock(current, &head, &flags); | |
298 | ||
299 | /* | |
300 | * It is possible to have multiple instances associated with a given | |
301 | * task either because an multiple functions in the call path | |
302 | * have a return probe installed on them, and/or more then one return | |
303 | * return probe was registered for a target function. | |
304 | * | |
305 | * We can handle this because: | |
306 | * - instances are always inserted at the head of the list | |
307 | * - when multiple return probes are registered for the same | |
308 | * function, the first instance's ret_addr will point to the | |
309 | * real return address, and all the rest will point to | |
310 | * kretprobe_trampoline | |
311 | */ | |
312 | hlist_for_each_entry_safe(ri, node, tmp, head, hlist) { | |
313 | if (ri->task != current) | |
314 | /* another task is sharing our hash bucket */ | |
315 | continue; | |
316 | ||
317 | if (ri->rp && ri->rp->handler) { | |
318 | __get_cpu_var(current_kprobe) = &ri->rp->kp; | |
319 | ri->rp->handler(ri, regs); | |
320 | __get_cpu_var(current_kprobe) = NULL; | |
321 | } | |
322 | ||
323 | orig_ret_address = (unsigned long)ri->ret_addr; | |
324 | recycle_rp_inst(ri, &empty_rp); | |
325 | ||
326 | if (orig_ret_address != trampoline_address) | |
327 | /* | |
328 | * This is the real return address. Any other | |
329 | * instances associated with this task are for | |
330 | * other calls deeper on the call stack | |
331 | */ | |
332 | break; | |
333 | } | |
334 | ||
335 | kretprobe_assert(ri, orig_ret_address, trampoline_address); | |
336 | ||
337 | regs->pc = orig_ret_address; | |
338 | kretprobe_hash_unlock(current, &flags); | |
339 | ||
340 | preempt_enable_no_resched(); | |
341 | ||
342 | hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) { | |
343 | hlist_del(&ri->hlist); | |
344 | kfree(ri); | |
345 | } | |
346 | ||
347 | return orig_ret_address; | |
348 | } | |
349 | ||
350 | static inline int post_kprobe_handler(struct pt_regs *regs) | |
351 | { | |
352 | struct kprobe *cur = kprobe_running(); | |
353 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); | |
354 | kprobe_opcode_t *addr = NULL; | |
355 | struct kprobe *p = NULL; | |
356 | ||
357 | if (!cur) | |
358 | return 0; | |
359 | ||
360 | if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) { | |
361 | kcb->kprobe_status = KPROBE_HIT_SSDONE; | |
362 | cur->post_handler(cur, regs, 0); | |
363 | } | |
364 | ||
365 | if (saved_next_opcode.addr != 0x0) { | |
366 | arch_disarm_kprobe(&saved_next_opcode); | |
367 | saved_next_opcode.addr = 0x0; | |
368 | saved_next_opcode.opcode = 0x0; | |
369 | ||
370 | addr = saved_current_opcode.addr; | |
371 | saved_current_opcode.addr = 0x0; | |
372 | ||
373 | p = get_kprobe(addr); | |
374 | arch_arm_kprobe(p); | |
375 | ||
376 | if (saved_next_opcode2.addr != 0x0) { | |
377 | arch_disarm_kprobe(&saved_next_opcode2); | |
378 | saved_next_opcode2.addr = 0x0; | |
379 | saved_next_opcode2.opcode = 0x0; | |
380 | } | |
381 | } | |
382 | ||
383 | /*Restore back the original saved kprobes variables and continue. */ | |
384 | if (kcb->kprobe_status == KPROBE_REENTER) { | |
385 | restore_previous_kprobe(kcb); | |
386 | goto out; | |
387 | } | |
388 | reset_current_kprobe(); | |
389 | ||
390 | out: | |
391 | preempt_enable_no_resched(); | |
392 | ||
393 | return 1; | |
394 | } | |
395 | ||
037c10a6 | 396 | int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr) |
d39f5450 CS |
397 | { |
398 | struct kprobe *cur = kprobe_running(); | |
399 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); | |
400 | const struct exception_table_entry *entry; | |
401 | ||
402 | switch (kcb->kprobe_status) { | |
403 | case KPROBE_HIT_SS: | |
404 | case KPROBE_REENTER: | |
405 | /* | |
406 | * We are here because the instruction being single | |
407 | * stepped caused a page fault. We reset the current | |
408 | * kprobe, point the pc back to the probe address | |
409 | * and allow the page fault handler to continue as a | |
410 | * normal page fault. | |
411 | */ | |
412 | regs->pc = (unsigned long)cur->addr; | |
413 | if (kcb->kprobe_status == KPROBE_REENTER) | |
414 | restore_previous_kprobe(kcb); | |
415 | else | |
416 | reset_current_kprobe(); | |
417 | preempt_enable_no_resched(); | |
418 | break; | |
419 | case KPROBE_HIT_ACTIVE: | |
420 | case KPROBE_HIT_SSDONE: | |
421 | /* | |
422 | * We increment the nmissed count for accounting, | |
423 | * we can also use npre/npostfault count for accounting | |
424 | * these specific fault cases. | |
425 | */ | |
426 | kprobes_inc_nmissed_count(cur); | |
427 | ||
428 | /* | |
429 | * We come here because instructions in the pre/post | |
430 | * handler caused the page_fault, this could happen | |
431 | * if handler tries to access user space by | |
432 | * copy_from_user(), get_user() etc. Let the | |
433 | * user-specified handler try to fix it first. | |
434 | */ | |
435 | if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr)) | |
436 | return 1; | |
437 | ||
438 | /* | |
439 | * In case the user-specified fault handler returned | |
440 | * zero, try to fix up. | |
441 | */ | |
442 | if ((entry = search_exception_tables(regs->pc)) != NULL) { | |
443 | regs->pc = entry->fixup; | |
444 | return 1; | |
445 | } | |
446 | ||
447 | /* | |
448 | * fixup_exception() could not handle it, | |
449 | * Let do_page_fault() fix it. | |
450 | */ | |
451 | break; | |
452 | default: | |
453 | break; | |
454 | } | |
455 | return 0; | |
456 | } | |
457 | ||
458 | /* | |
459 | * Wrapper routine to for handling exceptions. | |
460 | */ | |
461 | int __kprobes kprobe_exceptions_notify(struct notifier_block *self, | |
462 | unsigned long val, void *data) | |
463 | { | |
464 | struct kprobe *p = NULL; | |
465 | struct die_args *args = (struct die_args *)data; | |
466 | int ret = NOTIFY_DONE; | |
467 | kprobe_opcode_t *addr = NULL; | |
468 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); | |
469 | ||
470 | addr = (kprobe_opcode_t *) (args->regs->pc); | |
471 | if (val == DIE_TRAP) { | |
472 | if (!kprobe_running()) { | |
473 | if (kprobe_handler(args->regs)) { | |
474 | ret = NOTIFY_STOP; | |
475 | } else { | |
476 | /* Not a kprobe trap */ | |
ee386de7 | 477 | ret = NOTIFY_DONE; |
d39f5450 CS |
478 | } |
479 | } else { | |
480 | p = get_kprobe(addr); | |
481 | if ((kcb->kprobe_status == KPROBE_HIT_SS) || | |
482 | (kcb->kprobe_status == KPROBE_REENTER)) { | |
483 | if (post_kprobe_handler(args->regs)) | |
484 | ret = NOTIFY_STOP; | |
485 | } else { | |
486 | if (kprobe_handler(args->regs)) { | |
487 | ret = NOTIFY_STOP; | |
488 | } else { | |
489 | p = __get_cpu_var(current_kprobe); | |
490 | if (p->break_handler | |
491 | && p->break_handler(p, args->regs)) | |
492 | ret = NOTIFY_STOP; | |
493 | } | |
494 | } | |
495 | } | |
496 | } | |
497 | ||
498 | return ret; | |
499 | } | |
500 | ||
501 | int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) | |
502 | { | |
503 | struct jprobe *jp = container_of(p, struct jprobe, kp); | |
504 | unsigned long addr; | |
505 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); | |
506 | ||
507 | kcb->jprobe_saved_regs = *regs; | |
508 | kcb->jprobe_saved_r15 = regs->regs[15]; | |
509 | addr = kcb->jprobe_saved_r15; | |
510 | ||
511 | /* | |
512 | * TBD: As Linus pointed out, gcc assumes that the callee | |
513 | * owns the argument space and could overwrite it, e.g. | |
514 | * tailcall optimization. So, to be absolutely safe | |
515 | * we also save and restore enough stack bytes to cover | |
516 | * the argument area. | |
517 | */ | |
518 | memcpy(kcb->jprobes_stack, (kprobe_opcode_t *) addr, | |
519 | MIN_STACK_SIZE(addr)); | |
520 | ||
521 | regs->pc = (unsigned long)(jp->entry); | |
522 | ||
523 | return 1; | |
524 | } | |
525 | ||
526 | void __kprobes jprobe_return(void) | |
527 | { | |
174b5c99 | 528 | asm volatile ("trapa #0x3a\n\t" "jprobe_return_end:\n\t" "nop\n\t"); |
d39f5450 CS |
529 | } |
530 | ||
531 | int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) | |
532 | { | |
533 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); | |
534 | u8 *addr = (u8 *) regs->pc; | |
535 | unsigned long stack_addr = kcb->jprobe_saved_r15; | |
536 | ||
537 | if ((addr >= (u8 *) jprobe_return) | |
538 | && (addr <= (u8 *) jprobe_return_end)) { | |
539 | *regs = kcb->jprobe_saved_regs; | |
540 | ||
541 | memcpy((kprobe_opcode_t *) stack_addr, kcb->jprobes_stack, | |
542 | MIN_STACK_SIZE(stack_addr)); | |
543 | ||
544 | kcb->kprobe_status = KPROBE_HIT_SS; | |
247bc6d2 | 545 | preempt_enable_no_resched(); |
d39f5450 CS |
546 | return 1; |
547 | } | |
548 | return 0; | |
549 | } | |
550 | ||
551 | static struct kprobe trampoline_p = { | |
552 | .addr = (kprobe_opcode_t *) &kretprobe_trampoline, | |
553 | .pre_handler = trampoline_probe_handler | |
554 | }; | |
555 | ||
556 | int __init arch_init_kprobes(void) | |
557 | { | |
558 | saved_next_opcode.addr = 0x0; | |
559 | saved_next_opcode.opcode = 0x0; | |
560 | ||
561 | saved_current_opcode.addr = 0x0; | |
562 | saved_current_opcode.opcode = 0x0; | |
563 | ||
564 | saved_next_opcode2.addr = 0x0; | |
565 | saved_next_opcode2.opcode = 0x0; | |
566 | ||
567 | return register_kprobe(&trampoline_p); | |
568 | } |