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> | |
5a0e3ad6 | 16 | #include <linux/slab.h> |
d39f5450 CS |
17 | #include <asm/cacheflush.h> |
18 | #include <asm/uaccess.h> | |
19 | ||
20 | DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL; | |
21 | DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); | |
22 | ||
23 | static struct kprobe saved_current_opcode; | |
24 | static struct kprobe saved_next_opcode; | |
25 | static struct kprobe saved_next_opcode2; | |
26 | ||
27 | #define OPCODE_JMP(x) (((x) & 0xF0FF) == 0x402b) | |
28 | #define OPCODE_JSR(x) (((x) & 0xF0FF) == 0x400b) | |
29 | #define OPCODE_BRA(x) (((x) & 0xF000) == 0xa000) | |
30 | #define OPCODE_BRAF(x) (((x) & 0xF0FF) == 0x0023) | |
31 | #define OPCODE_BSR(x) (((x) & 0xF000) == 0xb000) | |
32 | #define OPCODE_BSRF(x) (((x) & 0xF0FF) == 0x0003) | |
33 | ||
34 | #define OPCODE_BF_S(x) (((x) & 0xFF00) == 0x8f00) | |
35 | #define OPCODE_BT_S(x) (((x) & 0xFF00) == 0x8d00) | |
36 | ||
37 | #define OPCODE_BF(x) (((x) & 0xFF00) == 0x8b00) | |
38 | #define OPCODE_BT(x) (((x) & 0xFF00) == 0x8900) | |
39 | ||
40 | #define OPCODE_RTS(x) (((x) & 0x000F) == 0x000b) | |
41 | #define OPCODE_RTE(x) (((x) & 0xFFFF) == 0x002b) | |
42 | ||
43 | int __kprobes arch_prepare_kprobe(struct kprobe *p) | |
44 | { | |
45 | kprobe_opcode_t opcode = *(kprobe_opcode_t *) (p->addr); | |
46 | ||
47 | if (OPCODE_RTE(opcode)) | |
48 | return -EFAULT; /* Bad breakpoint */ | |
49 | ||
50 | p->opcode = opcode; | |
51 | ||
52 | return 0; | |
53 | } | |
54 | ||
55 | void __kprobes arch_copy_kprobe(struct kprobe *p) | |
56 | { | |
57 | memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t)); | |
58 | p->opcode = *p->addr; | |
59 | } | |
60 | ||
61 | void __kprobes arch_arm_kprobe(struct kprobe *p) | |
62 | { | |
63 | *p->addr = BREAKPOINT_INSTRUCTION; | |
64 | flush_icache_range((unsigned long)p->addr, | |
65 | (unsigned long)p->addr + sizeof(kprobe_opcode_t)); | |
66 | } | |
67 | ||
68 | void __kprobes arch_disarm_kprobe(struct kprobe *p) | |
69 | { | |
70 | *p->addr = p->opcode; | |
71 | flush_icache_range((unsigned long)p->addr, | |
72 | (unsigned long)p->addr + sizeof(kprobe_opcode_t)); | |
73 | } | |
74 | ||
75 | int __kprobes arch_trampoline_kprobe(struct kprobe *p) | |
76 | { | |
77 | if (*p->addr == BREAKPOINT_INSTRUCTION) | |
78 | return 1; | |
79 | ||
80 | return 0; | |
81 | } | |
82 | ||
83 | /** | |
84 | * If an illegal slot instruction exception occurs for an address | |
85 | * containing a kprobe, remove the probe. | |
86 | * | |
87 | * Returns 0 if the exception was handled successfully, 1 otherwise. | |
88 | */ | |
89 | int __kprobes kprobe_handle_illslot(unsigned long pc) | |
90 | { | |
91 | struct kprobe *p = get_kprobe((kprobe_opcode_t *) pc + 1); | |
92 | ||
93 | if (p != NULL) { | |
94 | printk("Warning: removing kprobe from delay slot: 0x%.8x\n", | |
95 | (unsigned int)pc + 2); | |
96 | unregister_kprobe(p); | |
97 | return 0; | |
98 | } | |
99 | ||
100 | return 1; | |
101 | } | |
102 | ||
103 | void __kprobes arch_remove_kprobe(struct kprobe *p) | |
104 | { | |
105 | if (saved_next_opcode.addr != 0x0) { | |
106 | arch_disarm_kprobe(p); | |
107 | arch_disarm_kprobe(&saved_next_opcode); | |
108 | saved_next_opcode.addr = 0x0; | |
109 | saved_next_opcode.opcode = 0x0; | |
110 | ||
111 | if (saved_next_opcode2.addr != 0x0) { | |
112 | arch_disarm_kprobe(&saved_next_opcode2); | |
113 | saved_next_opcode2.addr = 0x0; | |
114 | saved_next_opcode2.opcode = 0x0; | |
115 | } | |
116 | } | |
117 | } | |
118 | ||
4eb5845d | 119 | static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb) |
d39f5450 CS |
120 | { |
121 | kcb->prev_kprobe.kp = kprobe_running(); | |
122 | kcb->prev_kprobe.status = kcb->kprobe_status; | |
123 | } | |
124 | ||
4eb5845d | 125 | static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb) |
d39f5450 CS |
126 | { |
127 | __get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp; | |
128 | kcb->kprobe_status = kcb->prev_kprobe.status; | |
129 | } | |
130 | ||
4eb5845d PM |
131 | static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs, |
132 | struct kprobe_ctlblk *kcb) | |
d39f5450 CS |
133 | { |
134 | __get_cpu_var(current_kprobe) = p; | |
135 | } | |
136 | ||
137 | /* | |
138 | * Singlestep is implemented by disabling the current kprobe and setting one | |
139 | * on the next instruction, following branches. Two probes are set if the | |
140 | * branch is conditional. | |
141 | */ | |
4eb5845d | 142 | static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs) |
d39f5450 CS |
143 | { |
144 | kprobe_opcode_t *addr = NULL; | |
145 | saved_current_opcode.addr = (kprobe_opcode_t *) (regs->pc); | |
146 | addr = saved_current_opcode.addr; | |
147 | ||
148 | if (p != NULL) { | |
149 | arch_disarm_kprobe(p); | |
150 | ||
151 | if (OPCODE_JSR(p->opcode) || OPCODE_JMP(p->opcode)) { | |
152 | unsigned int reg_nr = ((p->opcode >> 8) & 0x000F); | |
153 | saved_next_opcode.addr = | |
154 | (kprobe_opcode_t *) regs->regs[reg_nr]; | |
155 | } else if (OPCODE_BRA(p->opcode) || OPCODE_BSR(p->opcode)) { | |
156 | unsigned long disp = (p->opcode & 0x0FFF); | |
157 | saved_next_opcode.addr = | |
158 | (kprobe_opcode_t *) (regs->pc + 4 + disp * 2); | |
159 | ||
160 | } else if (OPCODE_BRAF(p->opcode) || OPCODE_BSRF(p->opcode)) { | |
161 | unsigned int reg_nr = ((p->opcode >> 8) & 0x000F); | |
162 | saved_next_opcode.addr = | |
163 | (kprobe_opcode_t *) (regs->pc + 4 + | |
164 | regs->regs[reg_nr]); | |
165 | ||
166 | } else if (OPCODE_RTS(p->opcode)) { | |
167 | saved_next_opcode.addr = (kprobe_opcode_t *) regs->pr; | |
168 | ||
169 | } else if (OPCODE_BF(p->opcode) || OPCODE_BT(p->opcode)) { | |
170 | unsigned long disp = (p->opcode & 0x00FF); | |
171 | /* case 1 */ | |
172 | saved_next_opcode.addr = p->addr + 1; | |
173 | /* case 2 */ | |
174 | saved_next_opcode2.addr = | |
175 | (kprobe_opcode_t *) (regs->pc + 4 + disp * 2); | |
176 | saved_next_opcode2.opcode = *(saved_next_opcode2.addr); | |
177 | arch_arm_kprobe(&saved_next_opcode2); | |
178 | ||
179 | } else if (OPCODE_BF_S(p->opcode) || OPCODE_BT_S(p->opcode)) { | |
180 | unsigned long disp = (p->opcode & 0x00FF); | |
181 | /* case 1 */ | |
182 | saved_next_opcode.addr = p->addr + 2; | |
183 | /* case 2 */ | |
184 | saved_next_opcode2.addr = | |
185 | (kprobe_opcode_t *) (regs->pc + 4 + disp * 2); | |
186 | saved_next_opcode2.opcode = *(saved_next_opcode2.addr); | |
187 | arch_arm_kprobe(&saved_next_opcode2); | |
188 | ||
189 | } else { | |
190 | saved_next_opcode.addr = p->addr + 1; | |
191 | } | |
192 | ||
193 | saved_next_opcode.opcode = *(saved_next_opcode.addr); | |
194 | arch_arm_kprobe(&saved_next_opcode); | |
195 | } | |
196 | } | |
197 | ||
198 | /* Called with kretprobe_lock held */ | |
199 | void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, | |
200 | struct pt_regs *regs) | |
201 | { | |
202 | ri->ret_addr = (kprobe_opcode_t *) regs->pr; | |
203 | ||
204 | /* Replace the return addr with trampoline addr */ | |
205 | regs->pr = (unsigned long)kretprobe_trampoline; | |
206 | } | |
207 | ||
208 | static int __kprobes kprobe_handler(struct pt_regs *regs) | |
209 | { | |
210 | struct kprobe *p; | |
211 | int ret = 0; | |
212 | kprobe_opcode_t *addr = NULL; | |
213 | struct kprobe_ctlblk *kcb; | |
214 | ||
215 | /* | |
216 | * We don't want to be preempted for the entire | |
217 | * duration of kprobe processing | |
218 | */ | |
219 | preempt_disable(); | |
220 | kcb = get_kprobe_ctlblk(); | |
221 | ||
222 | addr = (kprobe_opcode_t *) (regs->pc); | |
223 | ||
224 | /* Check we're not actually recursing */ | |
225 | if (kprobe_running()) { | |
226 | p = get_kprobe(addr); | |
227 | if (p) { | |
228 | if (kcb->kprobe_status == KPROBE_HIT_SS && | |
229 | *p->ainsn.insn == BREAKPOINT_INSTRUCTION) { | |
230 | goto no_kprobe; | |
231 | } | |
232 | /* We have reentered the kprobe_handler(), since | |
233 | * another probe was hit while within the handler. | |
234 | * We here save the original kprobes variables and | |
235 | * just single step on the instruction of the new probe | |
236 | * without calling any user handlers. | |
237 | */ | |
238 | save_previous_kprobe(kcb); | |
239 | set_current_kprobe(p, regs, kcb); | |
240 | kprobes_inc_nmissed_count(p); | |
241 | prepare_singlestep(p, regs); | |
242 | kcb->kprobe_status = KPROBE_REENTER; | |
243 | return 1; | |
244 | } else { | |
245 | p = __get_cpu_var(current_kprobe); | |
246 | if (p->break_handler && p->break_handler(p, regs)) { | |
247 | goto ss_probe; | |
248 | } | |
249 | } | |
250 | goto no_kprobe; | |
251 | } | |
252 | ||
253 | p = get_kprobe(addr); | |
254 | if (!p) { | |
255 | /* Not one of ours: let kernel handle it */ | |
734db377 PM |
256 | if (*(kprobe_opcode_t *)addr != BREAKPOINT_INSTRUCTION) { |
257 | /* | |
258 | * The breakpoint instruction was removed right | |
259 | * after we hit it. Another cpu has removed | |
260 | * either a probepoint or a debugger breakpoint | |
261 | * at this address. In either case, no further | |
262 | * handling of this interrupt is appropriate. | |
263 | */ | |
264 | ret = 1; | |
265 | } | |
266 | ||
d39f5450 CS |
267 | goto no_kprobe; |
268 | } | |
269 | ||
270 | set_current_kprobe(p, regs, kcb); | |
271 | kcb->kprobe_status = KPROBE_HIT_ACTIVE; | |
272 | ||
273 | if (p->pre_handler && p->pre_handler(p, regs)) | |
274 | /* handler has already set things up, so skip ss setup */ | |
275 | return 1; | |
276 | ||
4eb5845d | 277 | ss_probe: |
d39f5450 CS |
278 | prepare_singlestep(p, regs); |
279 | kcb->kprobe_status = KPROBE_HIT_SS; | |
280 | return 1; | |
281 | ||
4eb5845d | 282 | no_kprobe: |
d39f5450 CS |
283 | preempt_enable_no_resched(); |
284 | return ret; | |
285 | } | |
286 | ||
287 | /* | |
288 | * For function-return probes, init_kprobes() establishes a probepoint | |
289 | * here. When a retprobed function returns, this probe is hit and | |
290 | * trampoline_probe_handler() runs, calling the kretprobe's handler. | |
291 | */ | |
e7cb016e | 292 | static void __used kretprobe_trampoline_holder(void) |
d39f5450 | 293 | { |
6eb2139b PM |
294 | asm volatile (".globl kretprobe_trampoline\n" |
295 | "kretprobe_trampoline:\n\t" | |
296 | "nop\n"); | |
d39f5450 CS |
297 | } |
298 | ||
299 | /* | |
300 | * Called when we hit the probe point at kretprobe_trampoline | |
301 | */ | |
302 | int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) | |
303 | { | |
304 | struct kretprobe_instance *ri = NULL; | |
305 | struct hlist_head *head, empty_rp; | |
306 | struct hlist_node *node, *tmp; | |
307 | unsigned long flags, orig_ret_address = 0; | |
308 | unsigned long trampoline_address = (unsigned long)&kretprobe_trampoline; | |
309 | ||
310 | INIT_HLIST_HEAD(&empty_rp); | |
311 | kretprobe_hash_lock(current, &head, &flags); | |
312 | ||
313 | /* | |
314 | * It is possible to have multiple instances associated with a given | |
315 | * task either because an multiple functions in the call path | |
316 | * have a return probe installed on them, and/or more then one return | |
317 | * return probe was registered for a target function. | |
318 | * | |
319 | * We can handle this because: | |
320 | * - instances are always inserted at the head of the list | |
321 | * - when multiple return probes are registered for the same | |
322 | * function, the first instance's ret_addr will point to the | |
323 | * real return address, and all the rest will point to | |
324 | * kretprobe_trampoline | |
325 | */ | |
326 | hlist_for_each_entry_safe(ri, node, tmp, head, hlist) { | |
327 | if (ri->task != current) | |
328 | /* another task is sharing our hash bucket */ | |
329 | continue; | |
330 | ||
331 | if (ri->rp && ri->rp->handler) { | |
332 | __get_cpu_var(current_kprobe) = &ri->rp->kp; | |
333 | ri->rp->handler(ri, regs); | |
334 | __get_cpu_var(current_kprobe) = NULL; | |
335 | } | |
336 | ||
337 | orig_ret_address = (unsigned long)ri->ret_addr; | |
338 | recycle_rp_inst(ri, &empty_rp); | |
339 | ||
340 | if (orig_ret_address != trampoline_address) | |
341 | /* | |
342 | * This is the real return address. Any other | |
343 | * instances associated with this task are for | |
344 | * other calls deeper on the call stack | |
345 | */ | |
346 | break; | |
347 | } | |
348 | ||
349 | kretprobe_assert(ri, orig_ret_address, trampoline_address); | |
350 | ||
351 | regs->pc = orig_ret_address; | |
352 | kretprobe_hash_unlock(current, &flags); | |
353 | ||
354 | preempt_enable_no_resched(); | |
355 | ||
356 | hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) { | |
357 | hlist_del(&ri->hlist); | |
358 | kfree(ri); | |
359 | } | |
360 | ||
361 | return orig_ret_address; | |
362 | } | |
363 | ||
4eb5845d | 364 | static int __kprobes post_kprobe_handler(struct pt_regs *regs) |
d39f5450 CS |
365 | { |
366 | struct kprobe *cur = kprobe_running(); | |
367 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); | |
368 | kprobe_opcode_t *addr = NULL; | |
369 | struct kprobe *p = NULL; | |
370 | ||
371 | if (!cur) | |
372 | return 0; | |
373 | ||
374 | if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) { | |
375 | kcb->kprobe_status = KPROBE_HIT_SSDONE; | |
376 | cur->post_handler(cur, regs, 0); | |
377 | } | |
378 | ||
379 | if (saved_next_opcode.addr != 0x0) { | |
380 | arch_disarm_kprobe(&saved_next_opcode); | |
381 | saved_next_opcode.addr = 0x0; | |
382 | saved_next_opcode.opcode = 0x0; | |
383 | ||
384 | addr = saved_current_opcode.addr; | |
385 | saved_current_opcode.addr = 0x0; | |
386 | ||
387 | p = get_kprobe(addr); | |
388 | arch_arm_kprobe(p); | |
389 | ||
390 | if (saved_next_opcode2.addr != 0x0) { | |
391 | arch_disarm_kprobe(&saved_next_opcode2); | |
392 | saved_next_opcode2.addr = 0x0; | |
393 | saved_next_opcode2.opcode = 0x0; | |
394 | } | |
395 | } | |
396 | ||
4eb5845d | 397 | /* Restore back the original saved kprobes variables and continue. */ |
d39f5450 CS |
398 | if (kcb->kprobe_status == KPROBE_REENTER) { |
399 | restore_previous_kprobe(kcb); | |
400 | goto out; | |
401 | } | |
4eb5845d | 402 | |
d39f5450 CS |
403 | reset_current_kprobe(); |
404 | ||
4eb5845d | 405 | out: |
d39f5450 CS |
406 | preempt_enable_no_resched(); |
407 | ||
408 | return 1; | |
409 | } | |
410 | ||
037c10a6 | 411 | int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr) |
d39f5450 CS |
412 | { |
413 | struct kprobe *cur = kprobe_running(); | |
414 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); | |
415 | const struct exception_table_entry *entry; | |
416 | ||
417 | switch (kcb->kprobe_status) { | |
418 | case KPROBE_HIT_SS: | |
419 | case KPROBE_REENTER: | |
420 | /* | |
421 | * We are here because the instruction being single | |
422 | * stepped caused a page fault. We reset the current | |
423 | * kprobe, point the pc back to the probe address | |
424 | * and allow the page fault handler to continue as a | |
425 | * normal page fault. | |
426 | */ | |
427 | regs->pc = (unsigned long)cur->addr; | |
428 | if (kcb->kprobe_status == KPROBE_REENTER) | |
429 | restore_previous_kprobe(kcb); | |
430 | else | |
431 | reset_current_kprobe(); | |
432 | preempt_enable_no_resched(); | |
433 | break; | |
434 | case KPROBE_HIT_ACTIVE: | |
435 | case KPROBE_HIT_SSDONE: | |
436 | /* | |
437 | * We increment the nmissed count for accounting, | |
438 | * we can also use npre/npostfault count for accounting | |
439 | * these specific fault cases. | |
440 | */ | |
441 | kprobes_inc_nmissed_count(cur); | |
442 | ||
443 | /* | |
444 | * We come here because instructions in the pre/post | |
445 | * handler caused the page_fault, this could happen | |
446 | * if handler tries to access user space by | |
447 | * copy_from_user(), get_user() etc. Let the | |
448 | * user-specified handler try to fix it first. | |
449 | */ | |
450 | if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr)) | |
451 | return 1; | |
452 | ||
453 | /* | |
454 | * In case the user-specified fault handler returned | |
455 | * zero, try to fix up. | |
456 | */ | |
457 | if ((entry = search_exception_tables(regs->pc)) != NULL) { | |
458 | regs->pc = entry->fixup; | |
459 | return 1; | |
460 | } | |
461 | ||
462 | /* | |
463 | * fixup_exception() could not handle it, | |
464 | * Let do_page_fault() fix it. | |
465 | */ | |
466 | break; | |
467 | default: | |
468 | break; | |
469 | } | |
4eb5845d | 470 | |
d39f5450 CS |
471 | return 0; |
472 | } | |
473 | ||
474 | /* | |
475 | * Wrapper routine to for handling exceptions. | |
476 | */ | |
477 | int __kprobes kprobe_exceptions_notify(struct notifier_block *self, | |
478 | unsigned long val, void *data) | |
479 | { | |
480 | struct kprobe *p = NULL; | |
481 | struct die_args *args = (struct die_args *)data; | |
482 | int ret = NOTIFY_DONE; | |
483 | kprobe_opcode_t *addr = NULL; | |
484 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); | |
485 | ||
486 | addr = (kprobe_opcode_t *) (args->regs->pc); | |
487 | if (val == DIE_TRAP) { | |
488 | if (!kprobe_running()) { | |
489 | if (kprobe_handler(args->regs)) { | |
490 | ret = NOTIFY_STOP; | |
491 | } else { | |
492 | /* Not a kprobe trap */ | |
ee386de7 | 493 | ret = NOTIFY_DONE; |
d39f5450 CS |
494 | } |
495 | } else { | |
496 | p = get_kprobe(addr); | |
497 | if ((kcb->kprobe_status == KPROBE_HIT_SS) || | |
498 | (kcb->kprobe_status == KPROBE_REENTER)) { | |
499 | if (post_kprobe_handler(args->regs)) | |
500 | ret = NOTIFY_STOP; | |
501 | } else { | |
502 | if (kprobe_handler(args->regs)) { | |
503 | ret = NOTIFY_STOP; | |
504 | } else { | |
505 | p = __get_cpu_var(current_kprobe); | |
4eb5845d PM |
506 | if (p->break_handler && |
507 | p->break_handler(p, args->regs)) | |
d39f5450 CS |
508 | ret = NOTIFY_STOP; |
509 | } | |
510 | } | |
511 | } | |
512 | } | |
513 | ||
514 | return ret; | |
515 | } | |
516 | ||
517 | int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) | |
518 | { | |
519 | struct jprobe *jp = container_of(p, struct jprobe, kp); | |
520 | unsigned long addr; | |
521 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); | |
522 | ||
523 | kcb->jprobe_saved_regs = *regs; | |
524 | kcb->jprobe_saved_r15 = regs->regs[15]; | |
525 | addr = kcb->jprobe_saved_r15; | |
526 | ||
527 | /* | |
528 | * TBD: As Linus pointed out, gcc assumes that the callee | |
529 | * owns the argument space and could overwrite it, e.g. | |
530 | * tailcall optimization. So, to be absolutely safe | |
531 | * we also save and restore enough stack bytes to cover | |
532 | * the argument area. | |
533 | */ | |
534 | memcpy(kcb->jprobes_stack, (kprobe_opcode_t *) addr, | |
535 | MIN_STACK_SIZE(addr)); | |
536 | ||
537 | regs->pc = (unsigned long)(jp->entry); | |
538 | ||
539 | return 1; | |
540 | } | |
541 | ||
542 | void __kprobes jprobe_return(void) | |
543 | { | |
174b5c99 | 544 | asm volatile ("trapa #0x3a\n\t" "jprobe_return_end:\n\t" "nop\n\t"); |
d39f5450 CS |
545 | } |
546 | ||
547 | int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) | |
548 | { | |
549 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); | |
d39f5450 | 550 | unsigned long stack_addr = kcb->jprobe_saved_r15; |
4eb5845d | 551 | u8 *addr = (u8 *)regs->pc; |
d39f5450 | 552 | |
4eb5845d PM |
553 | if ((addr >= (u8 *)jprobe_return) && |
554 | (addr <= (u8 *)jprobe_return_end)) { | |
d39f5450 CS |
555 | *regs = kcb->jprobe_saved_regs; |
556 | ||
4eb5845d | 557 | memcpy((kprobe_opcode_t *)stack_addr, kcb->jprobes_stack, |
d39f5450 CS |
558 | MIN_STACK_SIZE(stack_addr)); |
559 | ||
560 | kcb->kprobe_status = KPROBE_HIT_SS; | |
247bc6d2 | 561 | preempt_enable_no_resched(); |
d39f5450 CS |
562 | return 1; |
563 | } | |
4eb5845d | 564 | |
d39f5450 CS |
565 | return 0; |
566 | } | |
567 | ||
568 | static struct kprobe trampoline_p = { | |
4eb5845d | 569 | .addr = (kprobe_opcode_t *)&kretprobe_trampoline, |
d39f5450 CS |
570 | .pre_handler = trampoline_probe_handler |
571 | }; | |
572 | ||
573 | int __init arch_init_kprobes(void) | |
574 | { | |
575 | saved_next_opcode.addr = 0x0; | |
576 | saved_next_opcode.opcode = 0x0; | |
577 | ||
578 | saved_current_opcode.addr = 0x0; | |
579 | saved_current_opcode.opcode = 0x0; | |
580 | ||
581 | saved_next_opcode2.addr = 0x0; | |
582 | saved_next_opcode2.opcode = 0x0; | |
583 | ||
584 | return register_kprobe(&trampoline_p); | |
585 | } |