Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Kernel Probes (KProbes) | |
1da177e4 LT |
3 | * |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License as published by | |
6 | * the Free Software Foundation; either version 2 of the License, or | |
7 | * (at your option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, write to the Free Software | |
16 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
17 | * | |
18 | * Copyright (C) IBM Corporation, 2002, 2004 | |
19 | * | |
20 | * 2002-Oct Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel | |
21 | * Probes initial implementation ( includes contributions from | |
22 | * Rusty Russell). | |
23 | * 2004-July Suparna Bhattacharya <suparna@in.ibm.com> added jumper probes | |
24 | * interface to access function arguments. | |
25 | * 2004-Nov Ananth N Mavinakayanahalli <ananth@in.ibm.com> kprobes port | |
26 | * for PPC64 | |
27 | */ | |
28 | ||
1da177e4 LT |
29 | #include <linux/kprobes.h> |
30 | #include <linux/ptrace.h> | |
1da177e4 | 31 | #include <linux/preempt.h> |
50e21f2b | 32 | #include <linux/module.h> |
1eeb66a1 | 33 | #include <linux/kdebug.h> |
5a0e3ad6 | 34 | #include <linux/slab.h> |
7e1048b1 | 35 | #include <asm/cacheflush.h> |
1da177e4 | 36 | #include <asm/sstep.h> |
50e21f2b | 37 | #include <asm/uaccess.h> |
f8279621 | 38 | |
0dc036c9 AM |
39 | DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL; |
40 | DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); | |
1da177e4 | 41 | |
f438d914 MH |
42 | struct kretprobe_blackpoint kretprobe_blacklist[] = {{NULL, NULL}}; |
43 | ||
bb144a85 | 44 | int __kprobes arch_prepare_kprobe(struct kprobe *p) |
1da177e4 | 45 | { |
63224d1e | 46 | int ret = 0; |
1da177e4 LT |
47 | kprobe_opcode_t insn = *p->addr; |
48 | ||
63224d1e AM |
49 | if ((unsigned long)p->addr & 0x03) { |
50 | printk("Attempt to register kprobe at an unaligned address\n"); | |
51 | ret = -EINVAL; | |
82090035 KG |
52 | } else if (IS_MTMSRD(insn) || IS_RFID(insn) || IS_RFI(insn)) { |
53 | printk("Cannot register a kprobe on rfi/rfid or mtmsr[d]\n"); | |
63224d1e AM |
54 | ret = -EINVAL; |
55 | } | |
9ec4b1f3 | 56 | |
f8279621 KG |
57 | /* insn must be on a special executable page on ppc64. This is |
58 | * not explicitly required on ppc32 (right now), but it doesn't hurt */ | |
9ec4b1f3 | 59 | if (!ret) { |
2d8ab6ad | 60 | p->ainsn.insn = get_insn_slot(); |
9ec4b1f3 AM |
61 | if (!p->ainsn.insn) |
62 | ret = -ENOMEM; | |
63 | } | |
1da177e4 | 64 | |
49a2a1b8 | 65 | if (!ret) { |
e6349a95 AM |
66 | memcpy(p->ainsn.insn, p->addr, |
67 | MAX_INSN_SIZE * sizeof(kprobe_opcode_t)); | |
49a2a1b8 | 68 | p->opcode = *p->addr; |
83db3dde AM |
69 | flush_icache_range((unsigned long)p->ainsn.insn, |
70 | (unsigned long)p->ainsn.insn + sizeof(kprobe_opcode_t)); | |
49a2a1b8 AK |
71 | } |
72 | ||
e6349a95 | 73 | p->ainsn.boostable = 0; |
49a2a1b8 | 74 | return ret; |
1da177e4 LT |
75 | } |
76 | ||
bb144a85 | 77 | void __kprobes arch_arm_kprobe(struct kprobe *p) |
1da177e4 | 78 | { |
7e1048b1 RL |
79 | *p->addr = BREAKPOINT_INSTRUCTION; |
80 | flush_icache_range((unsigned long) p->addr, | |
81 | (unsigned long) p->addr + sizeof(kprobe_opcode_t)); | |
1da177e4 LT |
82 | } |
83 | ||
bb144a85 | 84 | void __kprobes arch_disarm_kprobe(struct kprobe *p) |
1da177e4 LT |
85 | { |
86 | *p->addr = p->opcode; | |
7e1048b1 RL |
87 | flush_icache_range((unsigned long) p->addr, |
88 | (unsigned long) p->addr + sizeof(kprobe_opcode_t)); | |
89 | } | |
90 | ||
0498b635 | 91 | void __kprobes arch_remove_kprobe(struct kprobe *p) |
7e1048b1 | 92 | { |
12941560 MH |
93 | if (p->ainsn.insn) { |
94 | free_insn_slot(p->ainsn.insn, 0); | |
95 | p->ainsn.insn = NULL; | |
96 | } | |
1da177e4 LT |
97 | } |
98 | ||
46dbe2f4 | 99 | static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs) |
1da177e4 | 100 | { |
35fd219a | 101 | enable_single_step(regs); |
9ec4b1f3 | 102 | |
0ccde0a2 AM |
103 | /* |
104 | * On powerpc we should single step on the original | |
105 | * instruction even if the probed insn is a trap | |
106 | * variant as values in regs could play a part in | |
107 | * if the trap is taken or not | |
108 | */ | |
109 | regs->nip = (unsigned long)p->ainsn.insn; | |
1da177e4 LT |
110 | } |
111 | ||
46dbe2f4 | 112 | static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb) |
0dc036c9 AM |
113 | { |
114 | kcb->prev_kprobe.kp = kprobe_running(); | |
115 | kcb->prev_kprobe.status = kcb->kprobe_status; | |
116 | kcb->prev_kprobe.saved_msr = kcb->kprobe_saved_msr; | |
117 | } | |
118 | ||
46dbe2f4 | 119 | static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb) |
42cc2060 | 120 | { |
0dc036c9 AM |
121 | __get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp; |
122 | kcb->kprobe_status = kcb->prev_kprobe.status; | |
123 | kcb->kprobe_saved_msr = kcb->prev_kprobe.saved_msr; | |
42cc2060 PP |
124 | } |
125 | ||
46dbe2f4 | 126 | static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs, |
0dc036c9 | 127 | struct kprobe_ctlblk *kcb) |
42cc2060 | 128 | { |
0dc036c9 AM |
129 | __get_cpu_var(current_kprobe) = p; |
130 | kcb->kprobe_saved_msr = regs->msr; | |
42cc2060 PP |
131 | } |
132 | ||
4c4308cb | 133 | void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, |
bb144a85 | 134 | struct pt_regs *regs) |
97f7943d | 135 | { |
4c4308cb CH |
136 | ri->ret_addr = (kprobe_opcode_t *)regs->link; |
137 | ||
138 | /* Replace the return addr with trampoline addr */ | |
139 | regs->link = (unsigned long)kretprobe_trampoline; | |
97f7943d RL |
140 | } |
141 | ||
46dbe2f4 | 142 | static int __kprobes kprobe_handler(struct pt_regs *regs) |
1da177e4 LT |
143 | { |
144 | struct kprobe *p; | |
145 | int ret = 0; | |
146 | unsigned int *addr = (unsigned int *)regs->nip; | |
d217d545 AM |
147 | struct kprobe_ctlblk *kcb; |
148 | ||
149 | /* | |
150 | * We don't want to be preempted for the entire | |
151 | * duration of kprobe processing | |
152 | */ | |
153 | preempt_disable(); | |
154 | kcb = get_kprobe_ctlblk(); | |
1da177e4 LT |
155 | |
156 | /* Check we're not actually recursing */ | |
157 | if (kprobe_running()) { | |
1da177e4 LT |
158 | p = get_kprobe(addr); |
159 | if (p) { | |
deac66ae | 160 | kprobe_opcode_t insn = *p->ainsn.insn; |
0dc036c9 | 161 | if (kcb->kprobe_status == KPROBE_HIT_SS && |
deac66ae | 162 | is_trap(insn)) { |
f8279621 KG |
163 | /* Turn off 'trace' bits */ |
164 | regs->msr &= ~MSR_SINGLESTEP; | |
0dc036c9 | 165 | regs->msr |= kcb->kprobe_saved_msr; |
1da177e4 LT |
166 | goto no_kprobe; |
167 | } | |
42cc2060 PP |
168 | /* We have reentered the kprobe_handler(), since |
169 | * another probe was hit while within the handler. | |
170 | * We here save the original kprobes variables and | |
171 | * just single step on the instruction of the new probe | |
172 | * without calling any user handlers. | |
173 | */ | |
0dc036c9 AM |
174 | save_previous_kprobe(kcb); |
175 | set_current_kprobe(p, regs, kcb); | |
176 | kcb->kprobe_saved_msr = regs->msr; | |
bf8d5c52 | 177 | kprobes_inc_nmissed_count(p); |
42cc2060 | 178 | prepare_singlestep(p, regs); |
0dc036c9 | 179 | kcb->kprobe_status = KPROBE_REENTER; |
42cc2060 | 180 | return 1; |
1da177e4 | 181 | } else { |
eb3a7292 KA |
182 | if (*addr != BREAKPOINT_INSTRUCTION) { |
183 | /* If trap variant, then it belongs not to us */ | |
184 | kprobe_opcode_t cur_insn = *addr; | |
185 | if (is_trap(cur_insn)) | |
186 | goto no_kprobe; | |
187 | /* The breakpoint instruction was removed by | |
188 | * another cpu right after we hit, no further | |
189 | * handling of this interrupt is appropriate | |
190 | */ | |
191 | ret = 1; | |
192 | goto no_kprobe; | |
193 | } | |
0dc036c9 | 194 | p = __get_cpu_var(current_kprobe); |
1da177e4 LT |
195 | if (p->break_handler && p->break_handler(p, regs)) { |
196 | goto ss_probe; | |
197 | } | |
198 | } | |
1da177e4 LT |
199 | goto no_kprobe; |
200 | } | |
201 | ||
1da177e4 LT |
202 | p = get_kprobe(addr); |
203 | if (!p) { | |
1da177e4 LT |
204 | if (*addr != BREAKPOINT_INSTRUCTION) { |
205 | /* | |
206 | * PowerPC has multiple variants of the "trap" | |
207 | * instruction. If the current instruction is a | |
208 | * trap variant, it could belong to someone else | |
209 | */ | |
210 | kprobe_opcode_t cur_insn = *addr; | |
deac66ae | 211 | if (is_trap(cur_insn)) |
1da177e4 LT |
212 | goto no_kprobe; |
213 | /* | |
214 | * The breakpoint instruction was removed right | |
215 | * after we hit it. Another cpu has removed | |
216 | * either a probepoint or a debugger breakpoint | |
217 | * at this address. In either case, no further | |
218 | * handling of this interrupt is appropriate. | |
219 | */ | |
220 | ret = 1; | |
221 | } | |
222 | /* Not one of ours: let kernel handle it */ | |
223 | goto no_kprobe; | |
224 | } | |
225 | ||
0dc036c9 AM |
226 | kcb->kprobe_status = KPROBE_HIT_ACTIVE; |
227 | set_current_kprobe(p, regs, kcb); | |
1da177e4 LT |
228 | if (p->pre_handler && p->pre_handler(p, regs)) |
229 | /* handler has already set things up, so skip ss setup */ | |
230 | return 1; | |
231 | ||
232 | ss_probe: | |
e6349a95 AM |
233 | if (p->ainsn.boostable >= 0) { |
234 | unsigned int insn = *p->ainsn.insn; | |
235 | ||
236 | /* regs->nip is also adjusted if emulate_step returns 1 */ | |
237 | ret = emulate_step(regs, insn); | |
238 | if (ret > 0) { | |
239 | /* | |
240 | * Once this instruction has been boosted | |
241 | * successfully, set the boostable flag | |
242 | */ | |
243 | if (unlikely(p->ainsn.boostable == 0)) | |
244 | p->ainsn.boostable = 1; | |
245 | ||
246 | if (p->post_handler) | |
247 | p->post_handler(p, regs, 0); | |
248 | ||
249 | kcb->kprobe_status = KPROBE_HIT_SSDONE; | |
250 | reset_current_kprobe(); | |
251 | preempt_enable_no_resched(); | |
252 | return 1; | |
253 | } else if (ret < 0) { | |
254 | /* | |
255 | * We don't allow kprobes on mtmsr(d)/rfi(d), etc. | |
256 | * So, we should never get here... but, its still | |
257 | * good to catch them, just in case... | |
258 | */ | |
259 | printk("Can't step on instruction %x\n", insn); | |
260 | BUG(); | |
261 | } else if (ret == 0) | |
262 | /* This instruction can't be boosted */ | |
263 | p->ainsn.boostable = -1; | |
264 | } | |
1da177e4 | 265 | prepare_singlestep(p, regs); |
0dc036c9 | 266 | kcb->kprobe_status = KPROBE_HIT_SS; |
1da177e4 LT |
267 | return 1; |
268 | ||
269 | no_kprobe: | |
d217d545 | 270 | preempt_enable_no_resched(); |
1da177e4 LT |
271 | return ret; |
272 | } | |
273 | ||
97f7943d RL |
274 | /* |
275 | * Function return probe trampoline: | |
276 | * - init_kprobes() establishes a probepoint here | |
277 | * - When the probed function returns, this probe | |
278 | * causes the handlers to fire | |
279 | */ | |
66200ea2 | 280 | static void __used kretprobe_trampoline_holder(void) |
97f7943d RL |
281 | { |
282 | asm volatile(".global kretprobe_trampoline\n" | |
283 | "kretprobe_trampoline:\n" | |
284 | "nop\n"); | |
285 | } | |
286 | ||
287 | /* | |
288 | * Called when the probe at kretprobe trampoline is hit | |
289 | */ | |
66200ea2 AM |
290 | static int __kprobes trampoline_probe_handler(struct kprobe *p, |
291 | struct pt_regs *regs) | |
97f7943d | 292 | { |
62c27be0 | 293 | struct kretprobe_instance *ri = NULL; |
99219a3f | 294 | struct hlist_head *head, empty_rp; |
b67bfe0d | 295 | struct hlist_node *tmp; |
991a51d8 | 296 | unsigned long flags, orig_ret_address = 0; |
97f7943d RL |
297 | unsigned long trampoline_address =(unsigned long)&kretprobe_trampoline; |
298 | ||
99219a3f | 299 | INIT_HLIST_HEAD(&empty_rp); |
ef53d9c5 | 300 | kretprobe_hash_lock(current, &head, &flags); |
97f7943d RL |
301 | |
302 | /* | |
303 | * It is possible to have multiple instances associated with a given | |
304 | * task either because an multiple functions in the call path | |
025dfdaf | 305 | * have a return probe installed on them, and/or more than one return |
97f7943d RL |
306 | * return probe was registered for a target function. |
307 | * | |
308 | * We can handle this because: | |
309 | * - instances are always inserted at the head of the list | |
310 | * - when multiple return probes are registered for the same | |
62c27be0 | 311 | * function, the first instance's ret_addr will point to the |
97f7943d RL |
312 | * real return address, and all the rest will point to |
313 | * kretprobe_trampoline | |
314 | */ | |
b67bfe0d | 315 | hlist_for_each_entry_safe(ri, tmp, head, hlist) { |
62c27be0 | 316 | if (ri->task != current) |
97f7943d | 317 | /* another task is sharing our hash bucket */ |
62c27be0 | 318 | continue; |
97f7943d RL |
319 | |
320 | if (ri->rp && ri->rp->handler) | |
321 | ri->rp->handler(ri, regs); | |
322 | ||
323 | orig_ret_address = (unsigned long)ri->ret_addr; | |
99219a3f | 324 | recycle_rp_inst(ri, &empty_rp); |
97f7943d RL |
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 | ||
0f95b7fc | 335 | kretprobe_assert(ri, orig_ret_address, trampoline_address); |
97f7943d RL |
336 | regs->nip = orig_ret_address; |
337 | ||
0dc036c9 | 338 | reset_current_kprobe(); |
ef53d9c5 | 339 | kretprobe_hash_unlock(current, &flags); |
66ff2d06 | 340 | preempt_enable_no_resched(); |
97f7943d | 341 | |
b67bfe0d | 342 | hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) { |
99219a3f | 343 | hlist_del(&ri->hlist); |
344 | kfree(ri); | |
345 | } | |
62c27be0 | 346 | /* |
347 | * By returning a non-zero value, we are telling | |
348 | * kprobe_handler() that we don't want the post_handler | |
349 | * to run (and have re-enabled preemption) | |
350 | */ | |
351 | return 1; | |
97f7943d RL |
352 | } |
353 | ||
1da177e4 LT |
354 | /* |
355 | * Called after single-stepping. p->addr is the address of the | |
356 | * instruction whose first byte has been replaced by the "breakpoint" | |
357 | * instruction. To avoid the SMP problems that can occur when we | |
358 | * temporarily put back the original opcode to single-step, we | |
359 | * single-stepped a copy of the instruction. The address of this | |
360 | * copy is p->ainsn.insn. | |
361 | */ | |
46dbe2f4 | 362 | static int __kprobes post_kprobe_handler(struct pt_regs *regs) |
1da177e4 | 363 | { |
0dc036c9 AM |
364 | struct kprobe *cur = kprobe_running(); |
365 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); | |
366 | ||
367 | if (!cur) | |
1da177e4 LT |
368 | return 0; |
369 | ||
b76e59d1 KG |
370 | /* make sure we got here for instruction we have a kprobe on */ |
371 | if (((unsigned long)cur->ainsn.insn + 4) != regs->nip) | |
372 | return 0; | |
373 | ||
0dc036c9 AM |
374 | if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) { |
375 | kcb->kprobe_status = KPROBE_HIT_SSDONE; | |
376 | cur->post_handler(cur, regs, 0); | |
42cc2060 | 377 | } |
1da177e4 | 378 | |
db97bc7f AM |
379 | /* Adjust nip to after the single-stepped instruction */ |
380 | regs->nip = (unsigned long)cur->addr + 4; | |
0dc036c9 | 381 | regs->msr |= kcb->kprobe_saved_msr; |
1da177e4 | 382 | |
42cc2060 | 383 | /*Restore back the original saved kprobes variables and continue. */ |
0dc036c9 AM |
384 | if (kcb->kprobe_status == KPROBE_REENTER) { |
385 | restore_previous_kprobe(kcb); | |
42cc2060 PP |
386 | goto out; |
387 | } | |
0dc036c9 | 388 | reset_current_kprobe(); |
42cc2060 | 389 | out: |
1da177e4 LT |
390 | preempt_enable_no_resched(); |
391 | ||
392 | /* | |
393 | * if somebody else is singlestepping across a probe point, msr | |
f8279621 | 394 | * will have DE/SE set, in which case, continue the remaining processing |
1da177e4 LT |
395 | * of do_debug, as if this is not a probe hit. |
396 | */ | |
f8279621 | 397 | if (regs->msr & MSR_SINGLESTEP) |
1da177e4 LT |
398 | return 0; |
399 | ||
400 | return 1; | |
401 | } | |
402 | ||
9f90b997 | 403 | int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr) |
1da177e4 | 404 | { |
0dc036c9 AM |
405 | struct kprobe *cur = kprobe_running(); |
406 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); | |
50e21f2b PP |
407 | const struct exception_table_entry *entry; |
408 | ||
409 | switch(kcb->kprobe_status) { | |
410 | case KPROBE_HIT_SS: | |
411 | case KPROBE_REENTER: | |
412 | /* | |
413 | * We are here because the instruction being single | |
414 | * stepped caused a page fault. We reset the current | |
415 | * kprobe and the nip points back to the probe address | |
416 | * and allow the page fault handler to continue as a | |
417 | * normal page fault. | |
418 | */ | |
419 | regs->nip = (unsigned long)cur->addr; | |
f8279621 | 420 | regs->msr &= ~MSR_SINGLESTEP; /* Turn off 'trace' bits */ |
0dc036c9 | 421 | regs->msr |= kcb->kprobe_saved_msr; |
50e21f2b PP |
422 | if (kcb->kprobe_status == KPROBE_REENTER) |
423 | restore_previous_kprobe(kcb); | |
424 | else | |
425 | reset_current_kprobe(); | |
1da177e4 | 426 | preempt_enable_no_resched(); |
50e21f2b PP |
427 | break; |
428 | case KPROBE_HIT_ACTIVE: | |
429 | case KPROBE_HIT_SSDONE: | |
430 | /* | |
431 | * We increment the nmissed count for accounting, | |
23d6d3db | 432 | * we can also use npre/npostfault count for accounting |
50e21f2b PP |
433 | * these specific fault cases. |
434 | */ | |
435 | kprobes_inc_nmissed_count(cur); | |
436 | ||
437 | /* | |
438 | * We come here because instructions in the pre/post | |
439 | * handler caused the page_fault, this could happen | |
440 | * if handler tries to access user space by | |
441 | * copy_from_user(), get_user() etc. Let the | |
442 | * user-specified handler try to fix it first. | |
443 | */ | |
444 | if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr)) | |
445 | return 1; | |
446 | ||
447 | /* | |
448 | * In case the user-specified fault handler returned | |
449 | * zero, try to fix up. | |
450 | */ | |
451 | if ((entry = search_exception_tables(regs->nip)) != NULL) { | |
452 | regs->nip = entry->fixup; | |
453 | return 1; | |
454 | } | |
455 | ||
456 | /* | |
457 | * fixup_exception() could not handle it, | |
458 | * Let do_page_fault() fix it. | |
459 | */ | |
460 | break; | |
461 | default: | |
462 | break; | |
1da177e4 LT |
463 | } |
464 | return 0; | |
465 | } | |
466 | ||
467 | /* | |
468 | * Wrapper routine to for handling exceptions. | |
469 | */ | |
bb144a85 PP |
470 | int __kprobes kprobe_exceptions_notify(struct notifier_block *self, |
471 | unsigned long val, void *data) | |
1da177e4 LT |
472 | { |
473 | struct die_args *args = (struct die_args *)data; | |
474 | int ret = NOTIFY_DONE; | |
475 | ||
2326c770 | 476 | if (args->regs && user_mode(args->regs)) |
477 | return ret; | |
478 | ||
1da177e4 | 479 | switch (val) { |
1da177e4 LT |
480 | case DIE_BPT: |
481 | if (kprobe_handler(args->regs)) | |
482 | ret = NOTIFY_STOP; | |
483 | break; | |
484 | case DIE_SSTEP: | |
485 | if (post_kprobe_handler(args->regs)) | |
486 | ret = NOTIFY_STOP; | |
487 | break; | |
1da177e4 LT |
488 | default: |
489 | break; | |
490 | } | |
1da177e4 LT |
491 | return ret; |
492 | } | |
493 | ||
3d7e3382 ME |
494 | #ifdef CONFIG_PPC64 |
495 | unsigned long arch_deref_entry_point(void *entry) | |
496 | { | |
80d267f9 | 497 | return ((func_descr_t *)entry)->entry; |
3d7e3382 ME |
498 | } |
499 | #endif | |
500 | ||
bb144a85 | 501 | int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) |
1da177e4 LT |
502 | { |
503 | struct jprobe *jp = container_of(p, struct jprobe, kp); | |
0dc036c9 | 504 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); |
1da177e4 | 505 | |
0dc036c9 | 506 | memcpy(&kcb->jprobe_saved_regs, regs, sizeof(struct pt_regs)); |
1da177e4 LT |
507 | |
508 | /* setup return addr to the jprobe handler routine */ | |
3d7e3382 | 509 | regs->nip = arch_deref_entry_point(jp->entry); |
82090035 | 510 | #ifdef CONFIG_PPC64 |
1da177e4 | 511 | regs->gpr[2] = (unsigned long)(((func_descr_t *)jp->entry)->toc); |
82090035 | 512 | #endif |
1da177e4 LT |
513 | |
514 | return 1; | |
515 | } | |
516 | ||
66200ea2 | 517 | void __used __kprobes jprobe_return(void) |
1da177e4 LT |
518 | { |
519 | asm volatile("trap" ::: "memory"); | |
520 | } | |
521 | ||
66200ea2 | 522 | static void __used __kprobes jprobe_return_end(void) |
1da177e4 LT |
523 | { |
524 | }; | |
525 | ||
bb144a85 | 526 | int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) |
1da177e4 | 527 | { |
0dc036c9 AM |
528 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); |
529 | ||
1da177e4 LT |
530 | /* |
531 | * FIXME - we should ideally be validating that we got here 'cos | |
532 | * of the "trap" in jprobe_return() above, before restoring the | |
533 | * saved regs... | |
534 | */ | |
0dc036c9 | 535 | memcpy(regs, &kcb->jprobe_saved_regs, sizeof(struct pt_regs)); |
d217d545 | 536 | preempt_enable_no_resched(); |
1da177e4 LT |
537 | return 1; |
538 | } | |
97f7943d RL |
539 | |
540 | static struct kprobe trampoline_p = { | |
541 | .addr = (kprobe_opcode_t *) &kretprobe_trampoline, | |
542 | .pre_handler = trampoline_probe_handler | |
543 | }; | |
544 | ||
6772926b | 545 | int __init arch_init_kprobes(void) |
97f7943d RL |
546 | { |
547 | return register_kprobe(&trampoline_p); | |
548 | } | |
bf8f6e5b AM |
549 | |
550 | int __kprobes arch_trampoline_kprobe(struct kprobe *p) | |
551 | { | |
552 | if (p->addr == (kprobe_opcode_t *)&kretprobe_trampoline) | |
553 | return 1; | |
554 | ||
555 | return 0; | |
556 | } |