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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 | ||
4eb5845d | 118 | static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb) |
d39f5450 CS |
119 | { |
120 | kcb->prev_kprobe.kp = kprobe_running(); | |
121 | kcb->prev_kprobe.status = kcb->kprobe_status; | |
122 | } | |
123 | ||
4eb5845d | 124 | static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb) |
d39f5450 CS |
125 | { |
126 | __get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp; | |
127 | kcb->kprobe_status = kcb->prev_kprobe.status; | |
128 | } | |
129 | ||
4eb5845d PM |
130 | static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs, |
131 | struct kprobe_ctlblk *kcb) | |
d39f5450 CS |
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 | */ | |
4eb5845d | 141 | static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs) |
d39f5450 CS |
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 */ | |
734db377 PM |
255 | if (*(kprobe_opcode_t *)addr != BREAKPOINT_INSTRUCTION) { |
256 | /* | |
257 | * The breakpoint instruction was removed right | |
258 | * after we hit it. Another cpu has removed | |
259 | * either a probepoint or a debugger breakpoint | |
260 | * at this address. In either case, no further | |
261 | * handling of this interrupt is appropriate. | |
262 | */ | |
263 | ret = 1; | |
264 | } | |
265 | ||
d39f5450 CS |
266 | goto no_kprobe; |
267 | } | |
268 | ||
269 | set_current_kprobe(p, regs, kcb); | |
270 | kcb->kprobe_status = KPROBE_HIT_ACTIVE; | |
271 | ||
272 | if (p->pre_handler && p->pre_handler(p, regs)) | |
273 | /* handler has already set things up, so skip ss setup */ | |
274 | return 1; | |
275 | ||
4eb5845d | 276 | ss_probe: |
d39f5450 CS |
277 | prepare_singlestep(p, regs); |
278 | kcb->kprobe_status = KPROBE_HIT_SS; | |
279 | return 1; | |
280 | ||
4eb5845d | 281 | no_kprobe: |
d39f5450 CS |
282 | preempt_enable_no_resched(); |
283 | return ret; | |
284 | } | |
285 | ||
286 | /* | |
287 | * For function-return probes, init_kprobes() establishes a probepoint | |
288 | * here. When a retprobed function returns, this probe is hit and | |
289 | * trampoline_probe_handler() runs, calling the kretprobe's handler. | |
290 | */ | |
e7cb016e | 291 | static void __used kretprobe_trampoline_holder(void) |
d39f5450 | 292 | { |
6eb2139b PM |
293 | asm volatile (".globl kretprobe_trampoline\n" |
294 | "kretprobe_trampoline:\n\t" | |
295 | "nop\n"); | |
d39f5450 CS |
296 | } |
297 | ||
298 | /* | |
299 | * Called when we hit the probe point at kretprobe_trampoline | |
300 | */ | |
301 | int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) | |
302 | { | |
303 | struct kretprobe_instance *ri = NULL; | |
304 | struct hlist_head *head, empty_rp; | |
305 | struct hlist_node *node, *tmp; | |
306 | unsigned long flags, orig_ret_address = 0; | |
307 | unsigned long trampoline_address = (unsigned long)&kretprobe_trampoline; | |
308 | ||
309 | INIT_HLIST_HEAD(&empty_rp); | |
310 | kretprobe_hash_lock(current, &head, &flags); | |
311 | ||
312 | /* | |
313 | * It is possible to have multiple instances associated with a given | |
314 | * task either because an multiple functions in the call path | |
315 | * have a return probe installed on them, and/or more then one return | |
316 | * return probe was registered for a target function. | |
317 | * | |
318 | * We can handle this because: | |
319 | * - instances are always inserted at the head of the list | |
320 | * - when multiple return probes are registered for the same | |
321 | * function, the first instance's ret_addr will point to the | |
322 | * real return address, and all the rest will point to | |
323 | * kretprobe_trampoline | |
324 | */ | |
325 | hlist_for_each_entry_safe(ri, node, tmp, head, hlist) { | |
326 | if (ri->task != current) | |
327 | /* another task is sharing our hash bucket */ | |
328 | continue; | |
329 | ||
330 | if (ri->rp && ri->rp->handler) { | |
331 | __get_cpu_var(current_kprobe) = &ri->rp->kp; | |
332 | ri->rp->handler(ri, regs); | |
333 | __get_cpu_var(current_kprobe) = NULL; | |
334 | } | |
335 | ||
336 | orig_ret_address = (unsigned long)ri->ret_addr; | |
337 | recycle_rp_inst(ri, &empty_rp); | |
338 | ||
339 | if (orig_ret_address != trampoline_address) | |
340 | /* | |
341 | * This is the real return address. Any other | |
342 | * instances associated with this task are for | |
343 | * other calls deeper on the call stack | |
344 | */ | |
345 | break; | |
346 | } | |
347 | ||
348 | kretprobe_assert(ri, orig_ret_address, trampoline_address); | |
349 | ||
350 | regs->pc = orig_ret_address; | |
351 | kretprobe_hash_unlock(current, &flags); | |
352 | ||
353 | preempt_enable_no_resched(); | |
354 | ||
355 | hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) { | |
356 | hlist_del(&ri->hlist); | |
357 | kfree(ri); | |
358 | } | |
359 | ||
360 | return orig_ret_address; | |
361 | } | |
362 | ||
4eb5845d | 363 | static int __kprobes post_kprobe_handler(struct pt_regs *regs) |
d39f5450 CS |
364 | { |
365 | struct kprobe *cur = kprobe_running(); | |
366 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); | |
367 | kprobe_opcode_t *addr = NULL; | |
368 | struct kprobe *p = NULL; | |
369 | ||
370 | if (!cur) | |
371 | return 0; | |
372 | ||
373 | if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) { | |
374 | kcb->kprobe_status = KPROBE_HIT_SSDONE; | |
375 | cur->post_handler(cur, regs, 0); | |
376 | } | |
377 | ||
378 | if (saved_next_opcode.addr != 0x0) { | |
379 | arch_disarm_kprobe(&saved_next_opcode); | |
380 | saved_next_opcode.addr = 0x0; | |
381 | saved_next_opcode.opcode = 0x0; | |
382 | ||
383 | addr = saved_current_opcode.addr; | |
384 | saved_current_opcode.addr = 0x0; | |
385 | ||
386 | p = get_kprobe(addr); | |
387 | arch_arm_kprobe(p); | |
388 | ||
389 | if (saved_next_opcode2.addr != 0x0) { | |
390 | arch_disarm_kprobe(&saved_next_opcode2); | |
391 | saved_next_opcode2.addr = 0x0; | |
392 | saved_next_opcode2.opcode = 0x0; | |
393 | } | |
394 | } | |
395 | ||
4eb5845d | 396 | /* Restore back the original saved kprobes variables and continue. */ |
d39f5450 CS |
397 | if (kcb->kprobe_status == KPROBE_REENTER) { |
398 | restore_previous_kprobe(kcb); | |
399 | goto out; | |
400 | } | |
4eb5845d | 401 | |
d39f5450 CS |
402 | reset_current_kprobe(); |
403 | ||
4eb5845d | 404 | out: |
d39f5450 CS |
405 | preempt_enable_no_resched(); |
406 | ||
407 | return 1; | |
408 | } | |
409 | ||
037c10a6 | 410 | int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr) |
d39f5450 CS |
411 | { |
412 | struct kprobe *cur = kprobe_running(); | |
413 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); | |
414 | const struct exception_table_entry *entry; | |
415 | ||
416 | switch (kcb->kprobe_status) { | |
417 | case KPROBE_HIT_SS: | |
418 | case KPROBE_REENTER: | |
419 | /* | |
420 | * We are here because the instruction being single | |
421 | * stepped caused a page fault. We reset the current | |
422 | * kprobe, point the pc back to the probe address | |
423 | * and allow the page fault handler to continue as a | |
424 | * normal page fault. | |
425 | */ | |
426 | regs->pc = (unsigned long)cur->addr; | |
427 | if (kcb->kprobe_status == KPROBE_REENTER) | |
428 | restore_previous_kprobe(kcb); | |
429 | else | |
430 | reset_current_kprobe(); | |
431 | preempt_enable_no_resched(); | |
432 | break; | |
433 | case KPROBE_HIT_ACTIVE: | |
434 | case KPROBE_HIT_SSDONE: | |
435 | /* | |
436 | * We increment the nmissed count for accounting, | |
437 | * we can also use npre/npostfault count for accounting | |
438 | * these specific fault cases. | |
439 | */ | |
440 | kprobes_inc_nmissed_count(cur); | |
441 | ||
442 | /* | |
443 | * We come here because instructions in the pre/post | |
444 | * handler caused the page_fault, this could happen | |
445 | * if handler tries to access user space by | |
446 | * copy_from_user(), get_user() etc. Let the | |
447 | * user-specified handler try to fix it first. | |
448 | */ | |
449 | if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr)) | |
450 | return 1; | |
451 | ||
452 | /* | |
453 | * In case the user-specified fault handler returned | |
454 | * zero, try to fix up. | |
455 | */ | |
456 | if ((entry = search_exception_tables(regs->pc)) != NULL) { | |
457 | regs->pc = entry->fixup; | |
458 | return 1; | |
459 | } | |
460 | ||
461 | /* | |
462 | * fixup_exception() could not handle it, | |
463 | * Let do_page_fault() fix it. | |
464 | */ | |
465 | break; | |
466 | default: | |
467 | break; | |
468 | } | |
4eb5845d | 469 | |
d39f5450 CS |
470 | return 0; |
471 | } | |
472 | ||
473 | /* | |
474 | * Wrapper routine to for handling exceptions. | |
475 | */ | |
476 | int __kprobes kprobe_exceptions_notify(struct notifier_block *self, | |
477 | unsigned long val, void *data) | |
478 | { | |
479 | struct kprobe *p = NULL; | |
480 | struct die_args *args = (struct die_args *)data; | |
481 | int ret = NOTIFY_DONE; | |
482 | kprobe_opcode_t *addr = NULL; | |
483 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); | |
484 | ||
485 | addr = (kprobe_opcode_t *) (args->regs->pc); | |
486 | if (val == DIE_TRAP) { | |
487 | if (!kprobe_running()) { | |
488 | if (kprobe_handler(args->regs)) { | |
489 | ret = NOTIFY_STOP; | |
490 | } else { | |
491 | /* Not a kprobe trap */ | |
ee386de7 | 492 | ret = NOTIFY_DONE; |
d39f5450 CS |
493 | } |
494 | } else { | |
495 | p = get_kprobe(addr); | |
496 | if ((kcb->kprobe_status == KPROBE_HIT_SS) || | |
497 | (kcb->kprobe_status == KPROBE_REENTER)) { | |
498 | if (post_kprobe_handler(args->regs)) | |
499 | ret = NOTIFY_STOP; | |
500 | } else { | |
501 | if (kprobe_handler(args->regs)) { | |
502 | ret = NOTIFY_STOP; | |
503 | } else { | |
504 | p = __get_cpu_var(current_kprobe); | |
4eb5845d PM |
505 | if (p->break_handler && |
506 | p->break_handler(p, args->regs)) | |
d39f5450 CS |
507 | ret = NOTIFY_STOP; |
508 | } | |
509 | } | |
510 | } | |
511 | } | |
512 | ||
513 | return ret; | |
514 | } | |
515 | ||
516 | int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) | |
517 | { | |
518 | struct jprobe *jp = container_of(p, struct jprobe, kp); | |
519 | unsigned long addr; | |
520 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); | |
521 | ||
522 | kcb->jprobe_saved_regs = *regs; | |
523 | kcb->jprobe_saved_r15 = regs->regs[15]; | |
524 | addr = kcb->jprobe_saved_r15; | |
525 | ||
526 | /* | |
527 | * TBD: As Linus pointed out, gcc assumes that the callee | |
528 | * owns the argument space and could overwrite it, e.g. | |
529 | * tailcall optimization. So, to be absolutely safe | |
530 | * we also save and restore enough stack bytes to cover | |
531 | * the argument area. | |
532 | */ | |
533 | memcpy(kcb->jprobes_stack, (kprobe_opcode_t *) addr, | |
534 | MIN_STACK_SIZE(addr)); | |
535 | ||
536 | regs->pc = (unsigned long)(jp->entry); | |
537 | ||
538 | return 1; | |
539 | } | |
540 | ||
541 | void __kprobes jprobe_return(void) | |
542 | { | |
174b5c99 | 543 | asm volatile ("trapa #0x3a\n\t" "jprobe_return_end:\n\t" "nop\n\t"); |
d39f5450 CS |
544 | } |
545 | ||
546 | int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) | |
547 | { | |
548 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); | |
d39f5450 | 549 | unsigned long stack_addr = kcb->jprobe_saved_r15; |
4eb5845d | 550 | u8 *addr = (u8 *)regs->pc; |
d39f5450 | 551 | |
4eb5845d PM |
552 | if ((addr >= (u8 *)jprobe_return) && |
553 | (addr <= (u8 *)jprobe_return_end)) { | |
d39f5450 CS |
554 | *regs = kcb->jprobe_saved_regs; |
555 | ||
4eb5845d | 556 | memcpy((kprobe_opcode_t *)stack_addr, kcb->jprobes_stack, |
d39f5450 CS |
557 | MIN_STACK_SIZE(stack_addr)); |
558 | ||
559 | kcb->kprobe_status = KPROBE_HIT_SS; | |
247bc6d2 | 560 | preempt_enable_no_resched(); |
d39f5450 CS |
561 | return 1; |
562 | } | |
4eb5845d | 563 | |
d39f5450 CS |
564 | return 0; |
565 | } | |
566 | ||
567 | static struct kprobe trampoline_p = { | |
4eb5845d | 568 | .addr = (kprobe_opcode_t *)&kretprobe_trampoline, |
d39f5450 CS |
569 | .pre_handler = trampoline_probe_handler |
570 | }; | |
571 | ||
572 | int __init arch_init_kprobes(void) | |
573 | { | |
574 | saved_next_opcode.addr = 0x0; | |
575 | saved_next_opcode.opcode = 0x0; | |
576 | ||
577 | saved_current_opcode.addr = 0x0; | |
578 | saved_current_opcode.opcode = 0x0; | |
579 | ||
580 | saved_next_opcode2.addr = 0x0; | |
581 | saved_next_opcode2.opcode = 0x0; | |
582 | ||
583 | return register_kprobe(&trampoline_p); | |
584 | } |