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1da177e4 LT |
1 | /* |
2 | * Kernel Probes (KProbes) | |
3 | * kernel/kprobes.c | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License as published by | |
7 | * the Free Software Foundation; either version 2 of the License, or | |
8 | * (at your option) any later version. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
18 | * | |
19 | * Copyright (C) IBM Corporation, 2002, 2004 | |
20 | * | |
21 | * 2002-Oct Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel | |
22 | * Probes initial implementation (includes suggestions from | |
23 | * Rusty Russell). | |
24 | * 2004-Aug Updated by Prasanna S Panchamukhi <prasanna@in.ibm.com> with | |
25 | * hlists and exceptions notifier as suggested by Andi Kleen. | |
26 | * 2004-July Suparna Bhattacharya <suparna@in.ibm.com> added jumper probes | |
27 | * interface to access function arguments. | |
28 | * 2004-Sep Prasanna S Panchamukhi <prasanna@in.ibm.com> Changed Kprobes | |
29 | * exceptions notifier to be first on the priority list. | |
b94cce92 HN |
30 | * 2005-May Hien Nguyen <hien@us.ibm.com>, Jim Keniston |
31 | * <jkenisto@us.ibm.com> and Prasanna S Panchamukhi | |
32 | * <prasanna@in.ibm.com> added function-return probes. | |
1da177e4 LT |
33 | */ |
34 | #include <linux/kprobes.h> | |
1da177e4 LT |
35 | #include <linux/hash.h> |
36 | #include <linux/init.h> | |
4e57b681 | 37 | #include <linux/slab.h> |
e3869792 | 38 | #include <linux/stddef.h> |
1da177e4 | 39 | #include <linux/module.h> |
9ec4b1f3 | 40 | #include <linux/moduleloader.h> |
3a872d89 | 41 | #include <linux/kallsyms.h> |
b4c6c34a | 42 | #include <linux/freezer.h> |
346fd59b SD |
43 | #include <linux/seq_file.h> |
44 | #include <linux/debugfs.h> | |
1eeb66a1 | 45 | #include <linux/kdebug.h> |
4460fdad | 46 | #include <linux/memory.h> |
bf8f6e5b | 47 | |
d0aaff97 | 48 | #include <asm-generic/sections.h> |
1da177e4 LT |
49 | #include <asm/cacheflush.h> |
50 | #include <asm/errno.h> | |
bf8f6e5b | 51 | #include <asm/uaccess.h> |
1da177e4 LT |
52 | |
53 | #define KPROBE_HASH_BITS 6 | |
54 | #define KPROBE_TABLE_SIZE (1 << KPROBE_HASH_BITS) | |
55 | ||
3a872d89 AM |
56 | |
57 | /* | |
58 | * Some oddball architectures like 64bit powerpc have function descriptors | |
59 | * so this must be overridable. | |
60 | */ | |
61 | #ifndef kprobe_lookup_name | |
62 | #define kprobe_lookup_name(name, addr) \ | |
63 | addr = ((kprobe_opcode_t *)(kallsyms_lookup_name(name))) | |
64 | #endif | |
65 | ||
ef53d9c5 | 66 | static int kprobes_initialized; |
1da177e4 | 67 | static struct hlist_head kprobe_table[KPROBE_TABLE_SIZE]; |
b94cce92 | 68 | static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE]; |
1da177e4 | 69 | |
bf8f6e5b | 70 | /* NOTE: change this value only with kprobe_mutex held */ |
e579abeb | 71 | static bool kprobes_all_disarmed; |
bf8f6e5b | 72 | |
12941560 | 73 | static DEFINE_MUTEX(kprobe_mutex); /* Protects kprobe_table */ |
e6584523 | 74 | static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL; |
ef53d9c5 | 75 | static struct { |
7e036d04 | 76 | spinlock_t lock ____cacheline_aligned_in_smp; |
ef53d9c5 S |
77 | } kretprobe_table_locks[KPROBE_TABLE_SIZE]; |
78 | ||
79 | static spinlock_t *kretprobe_table_lock_ptr(unsigned long hash) | |
80 | { | |
81 | return &(kretprobe_table_locks[hash].lock); | |
82 | } | |
1da177e4 | 83 | |
3d8d996e SD |
84 | /* |
85 | * Normally, functions that we'd want to prohibit kprobes in, are marked | |
86 | * __kprobes. But, there are cases where such functions already belong to | |
87 | * a different section (__sched for preempt_schedule) | |
88 | * | |
89 | * For such cases, we now have a blacklist | |
90 | */ | |
544304b2 | 91 | static struct kprobe_blackpoint kprobe_blacklist[] = { |
3d8d996e SD |
92 | {"preempt_schedule",}, |
93 | {NULL} /* Terminator */ | |
94 | }; | |
95 | ||
2d14e39d | 96 | #ifdef __ARCH_WANT_KPROBES_INSN_SLOT |
9ec4b1f3 AM |
97 | /* |
98 | * kprobe->ainsn.insn points to the copy of the instruction to be | |
99 | * single-stepped. x86_64, POWER4 and above have no-exec support and | |
100 | * stepping on the instruction on a vmalloced/kmalloced/data page | |
101 | * is a recipe for disaster | |
102 | */ | |
103 | #define INSNS_PER_PAGE (PAGE_SIZE/(MAX_INSN_SIZE * sizeof(kprobe_opcode_t))) | |
104 | ||
105 | struct kprobe_insn_page { | |
106 | struct hlist_node hlist; | |
107 | kprobe_opcode_t *insns; /* Page of instruction slots */ | |
108 | char slot_used[INSNS_PER_PAGE]; | |
109 | int nused; | |
b4c6c34a | 110 | int ngarbage; |
9ec4b1f3 AM |
111 | }; |
112 | ||
ab40c5c6 MH |
113 | enum kprobe_slot_state { |
114 | SLOT_CLEAN = 0, | |
115 | SLOT_DIRTY = 1, | |
116 | SLOT_USED = 2, | |
117 | }; | |
118 | ||
12941560 | 119 | static DEFINE_MUTEX(kprobe_insn_mutex); /* Protects kprobe_insn_pages */ |
9ec4b1f3 | 120 | static struct hlist_head kprobe_insn_pages; |
b4c6c34a MH |
121 | static int kprobe_garbage_slots; |
122 | static int collect_garbage_slots(void); | |
123 | ||
124 | static int __kprobes check_safety(void) | |
125 | { | |
126 | int ret = 0; | |
5a4ccaf3 | 127 | #if defined(CONFIG_PREEMPT) && defined(CONFIG_FREEZER) |
b4c6c34a MH |
128 | ret = freeze_processes(); |
129 | if (ret == 0) { | |
130 | struct task_struct *p, *q; | |
131 | do_each_thread(p, q) { | |
132 | if (p != current && p->state == TASK_RUNNING && | |
133 | p->pid != 0) { | |
134 | printk("Check failed: %s is running\n",p->comm); | |
135 | ret = -1; | |
136 | goto loop_end; | |
137 | } | |
138 | } while_each_thread(p, q); | |
139 | } | |
140 | loop_end: | |
141 | thaw_processes(); | |
142 | #else | |
143 | synchronize_sched(); | |
144 | #endif | |
145 | return ret; | |
146 | } | |
9ec4b1f3 AM |
147 | |
148 | /** | |
12941560 | 149 | * __get_insn_slot() - Find a slot on an executable page for an instruction. |
9ec4b1f3 AM |
150 | * We allocate an executable page if there's no room on existing ones. |
151 | */ | |
12941560 | 152 | static kprobe_opcode_t __kprobes *__get_insn_slot(void) |
9ec4b1f3 AM |
153 | { |
154 | struct kprobe_insn_page *kip; | |
155 | struct hlist_node *pos; | |
156 | ||
6f716acd | 157 | retry: |
b0bb5016 | 158 | hlist_for_each_entry(kip, pos, &kprobe_insn_pages, hlist) { |
9ec4b1f3 AM |
159 | if (kip->nused < INSNS_PER_PAGE) { |
160 | int i; | |
161 | for (i = 0; i < INSNS_PER_PAGE; i++) { | |
ab40c5c6 MH |
162 | if (kip->slot_used[i] == SLOT_CLEAN) { |
163 | kip->slot_used[i] = SLOT_USED; | |
9ec4b1f3 AM |
164 | kip->nused++; |
165 | return kip->insns + (i * MAX_INSN_SIZE); | |
166 | } | |
167 | } | |
168 | /* Surprise! No unused slots. Fix kip->nused. */ | |
169 | kip->nused = INSNS_PER_PAGE; | |
170 | } | |
171 | } | |
172 | ||
b4c6c34a MH |
173 | /* If there are any garbage slots, collect it and try again. */ |
174 | if (kprobe_garbage_slots && collect_garbage_slots() == 0) { | |
175 | goto retry; | |
176 | } | |
177 | /* All out of space. Need to allocate a new page. Use slot 0. */ | |
9ec4b1f3 | 178 | kip = kmalloc(sizeof(struct kprobe_insn_page), GFP_KERNEL); |
6f716acd | 179 | if (!kip) |
9ec4b1f3 | 180 | return NULL; |
9ec4b1f3 AM |
181 | |
182 | /* | |
183 | * Use module_alloc so this page is within +/- 2GB of where the | |
184 | * kernel image and loaded module images reside. This is required | |
185 | * so x86_64 can correctly handle the %rip-relative fixups. | |
186 | */ | |
187 | kip->insns = module_alloc(PAGE_SIZE); | |
188 | if (!kip->insns) { | |
189 | kfree(kip); | |
190 | return NULL; | |
191 | } | |
192 | INIT_HLIST_NODE(&kip->hlist); | |
193 | hlist_add_head(&kip->hlist, &kprobe_insn_pages); | |
ab40c5c6 MH |
194 | memset(kip->slot_used, SLOT_CLEAN, INSNS_PER_PAGE); |
195 | kip->slot_used[0] = SLOT_USED; | |
9ec4b1f3 | 196 | kip->nused = 1; |
b4c6c34a | 197 | kip->ngarbage = 0; |
9ec4b1f3 AM |
198 | return kip->insns; |
199 | } | |
200 | ||
12941560 MH |
201 | kprobe_opcode_t __kprobes *get_insn_slot(void) |
202 | { | |
203 | kprobe_opcode_t *ret; | |
204 | mutex_lock(&kprobe_insn_mutex); | |
205 | ret = __get_insn_slot(); | |
206 | mutex_unlock(&kprobe_insn_mutex); | |
207 | return ret; | |
208 | } | |
209 | ||
b4c6c34a MH |
210 | /* Return 1 if all garbages are collected, otherwise 0. */ |
211 | static int __kprobes collect_one_slot(struct kprobe_insn_page *kip, int idx) | |
212 | { | |
ab40c5c6 | 213 | kip->slot_used[idx] = SLOT_CLEAN; |
b4c6c34a MH |
214 | kip->nused--; |
215 | if (kip->nused == 0) { | |
216 | /* | |
217 | * Page is no longer in use. Free it unless | |
218 | * it's the last one. We keep the last one | |
219 | * so as not to have to set it up again the | |
220 | * next time somebody inserts a probe. | |
221 | */ | |
222 | hlist_del(&kip->hlist); | |
223 | if (hlist_empty(&kprobe_insn_pages)) { | |
224 | INIT_HLIST_NODE(&kip->hlist); | |
225 | hlist_add_head(&kip->hlist, | |
226 | &kprobe_insn_pages); | |
227 | } else { | |
228 | module_free(NULL, kip->insns); | |
229 | kfree(kip); | |
230 | } | |
231 | return 1; | |
232 | } | |
233 | return 0; | |
234 | } | |
235 | ||
236 | static int __kprobes collect_garbage_slots(void) | |
237 | { | |
238 | struct kprobe_insn_page *kip; | |
239 | struct hlist_node *pos, *next; | |
12941560 | 240 | int safety; |
b4c6c34a MH |
241 | |
242 | /* Ensure no-one is preepmted on the garbages */ | |
12941560 MH |
243 | mutex_unlock(&kprobe_insn_mutex); |
244 | safety = check_safety(); | |
245 | mutex_lock(&kprobe_insn_mutex); | |
246 | if (safety != 0) | |
b4c6c34a MH |
247 | return -EAGAIN; |
248 | ||
b0bb5016 | 249 | hlist_for_each_entry_safe(kip, pos, next, &kprobe_insn_pages, hlist) { |
b4c6c34a | 250 | int i; |
b4c6c34a MH |
251 | if (kip->ngarbage == 0) |
252 | continue; | |
253 | kip->ngarbage = 0; /* we will collect all garbages */ | |
254 | for (i = 0; i < INSNS_PER_PAGE; i++) { | |
ab40c5c6 | 255 | if (kip->slot_used[i] == SLOT_DIRTY && |
b4c6c34a MH |
256 | collect_one_slot(kip, i)) |
257 | break; | |
258 | } | |
259 | } | |
260 | kprobe_garbage_slots = 0; | |
261 | return 0; | |
262 | } | |
263 | ||
264 | void __kprobes free_insn_slot(kprobe_opcode_t * slot, int dirty) | |
9ec4b1f3 AM |
265 | { |
266 | struct kprobe_insn_page *kip; | |
267 | struct hlist_node *pos; | |
268 | ||
12941560 | 269 | mutex_lock(&kprobe_insn_mutex); |
b0bb5016 | 270 | hlist_for_each_entry(kip, pos, &kprobe_insn_pages, hlist) { |
9ec4b1f3 AM |
271 | if (kip->insns <= slot && |
272 | slot < kip->insns + (INSNS_PER_PAGE * MAX_INSN_SIZE)) { | |
273 | int i = (slot - kip->insns) / MAX_INSN_SIZE; | |
b4c6c34a | 274 | if (dirty) { |
ab40c5c6 | 275 | kip->slot_used[i] = SLOT_DIRTY; |
b4c6c34a MH |
276 | kip->ngarbage++; |
277 | } else { | |
278 | collect_one_slot(kip, i); | |
9ec4b1f3 | 279 | } |
b4c6c34a | 280 | break; |
9ec4b1f3 AM |
281 | } |
282 | } | |
6f716acd CH |
283 | |
284 | if (dirty && ++kprobe_garbage_slots > INSNS_PER_PAGE) | |
b4c6c34a | 285 | collect_garbage_slots(); |
12941560 MH |
286 | |
287 | mutex_unlock(&kprobe_insn_mutex); | |
9ec4b1f3 | 288 | } |
2d14e39d | 289 | #endif |
9ec4b1f3 | 290 | |
e6584523 AM |
291 | /* We have preemption disabled.. so it is safe to use __ versions */ |
292 | static inline void set_kprobe_instance(struct kprobe *kp) | |
293 | { | |
294 | __get_cpu_var(kprobe_instance) = kp; | |
295 | } | |
296 | ||
297 | static inline void reset_kprobe_instance(void) | |
298 | { | |
299 | __get_cpu_var(kprobe_instance) = NULL; | |
300 | } | |
301 | ||
3516a460 AM |
302 | /* |
303 | * This routine is called either: | |
49a2a1b8 | 304 | * - under the kprobe_mutex - during kprobe_[un]register() |
3516a460 | 305 | * OR |
d217d545 | 306 | * - with preemption disabled - from arch/xxx/kernel/kprobes.c |
3516a460 | 307 | */ |
d0aaff97 | 308 | struct kprobe __kprobes *get_kprobe(void *addr) |
1da177e4 LT |
309 | { |
310 | struct hlist_head *head; | |
311 | struct hlist_node *node; | |
3516a460 | 312 | struct kprobe *p; |
1da177e4 LT |
313 | |
314 | head = &kprobe_table[hash_ptr(addr, KPROBE_HASH_BITS)]; | |
3516a460 | 315 | hlist_for_each_entry_rcu(p, node, head, hlist) { |
1da177e4 LT |
316 | if (p->addr == addr) |
317 | return p; | |
318 | } | |
319 | return NULL; | |
320 | } | |
321 | ||
201517a7 MH |
322 | /* Arm a kprobe with text_mutex */ |
323 | static void __kprobes arm_kprobe(struct kprobe *kp) | |
324 | { | |
325 | mutex_lock(&text_mutex); | |
326 | arch_arm_kprobe(kp); | |
327 | mutex_unlock(&text_mutex); | |
328 | } | |
329 | ||
330 | /* Disarm a kprobe with text_mutex */ | |
331 | static void __kprobes disarm_kprobe(struct kprobe *kp) | |
332 | { | |
333 | mutex_lock(&text_mutex); | |
334 | arch_disarm_kprobe(kp); | |
335 | mutex_unlock(&text_mutex); | |
336 | } | |
337 | ||
64f562c6 AM |
338 | /* |
339 | * Aggregate handlers for multiple kprobes support - these handlers | |
340 | * take care of invoking the individual kprobe handlers on p->list | |
341 | */ | |
d0aaff97 | 342 | static int __kprobes aggr_pre_handler(struct kprobe *p, struct pt_regs *regs) |
64f562c6 AM |
343 | { |
344 | struct kprobe *kp; | |
345 | ||
3516a460 | 346 | list_for_each_entry_rcu(kp, &p->list, list) { |
de5bd88d | 347 | if (kp->pre_handler && likely(!kprobe_disabled(kp))) { |
e6584523 | 348 | set_kprobe_instance(kp); |
8b0914ea PP |
349 | if (kp->pre_handler(kp, regs)) |
350 | return 1; | |
64f562c6 | 351 | } |
e6584523 | 352 | reset_kprobe_instance(); |
64f562c6 AM |
353 | } |
354 | return 0; | |
355 | } | |
356 | ||
d0aaff97 PP |
357 | static void __kprobes aggr_post_handler(struct kprobe *p, struct pt_regs *regs, |
358 | unsigned long flags) | |
64f562c6 AM |
359 | { |
360 | struct kprobe *kp; | |
361 | ||
3516a460 | 362 | list_for_each_entry_rcu(kp, &p->list, list) { |
de5bd88d | 363 | if (kp->post_handler && likely(!kprobe_disabled(kp))) { |
e6584523 | 364 | set_kprobe_instance(kp); |
64f562c6 | 365 | kp->post_handler(kp, regs, flags); |
e6584523 | 366 | reset_kprobe_instance(); |
64f562c6 AM |
367 | } |
368 | } | |
64f562c6 AM |
369 | } |
370 | ||
d0aaff97 PP |
371 | static int __kprobes aggr_fault_handler(struct kprobe *p, struct pt_regs *regs, |
372 | int trapnr) | |
64f562c6 | 373 | { |
e6584523 AM |
374 | struct kprobe *cur = __get_cpu_var(kprobe_instance); |
375 | ||
64f562c6 AM |
376 | /* |
377 | * if we faulted "during" the execution of a user specified | |
378 | * probe handler, invoke just that probe's fault handler | |
379 | */ | |
e6584523 AM |
380 | if (cur && cur->fault_handler) { |
381 | if (cur->fault_handler(cur, regs, trapnr)) | |
64f562c6 AM |
382 | return 1; |
383 | } | |
384 | return 0; | |
385 | } | |
386 | ||
d0aaff97 | 387 | static int __kprobes aggr_break_handler(struct kprobe *p, struct pt_regs *regs) |
8b0914ea | 388 | { |
e6584523 AM |
389 | struct kprobe *cur = __get_cpu_var(kprobe_instance); |
390 | int ret = 0; | |
391 | ||
392 | if (cur && cur->break_handler) { | |
393 | if (cur->break_handler(cur, regs)) | |
394 | ret = 1; | |
8b0914ea | 395 | } |
e6584523 AM |
396 | reset_kprobe_instance(); |
397 | return ret; | |
8b0914ea PP |
398 | } |
399 | ||
bf8d5c52 KA |
400 | /* Walks the list and increments nmissed count for multiprobe case */ |
401 | void __kprobes kprobes_inc_nmissed_count(struct kprobe *p) | |
402 | { | |
403 | struct kprobe *kp; | |
404 | if (p->pre_handler != aggr_pre_handler) { | |
405 | p->nmissed++; | |
406 | } else { | |
407 | list_for_each_entry_rcu(kp, &p->list, list) | |
408 | kp->nmissed++; | |
409 | } | |
410 | return; | |
411 | } | |
412 | ||
99219a3f | 413 | void __kprobes recycle_rp_inst(struct kretprobe_instance *ri, |
414 | struct hlist_head *head) | |
b94cce92 | 415 | { |
ef53d9c5 S |
416 | struct kretprobe *rp = ri->rp; |
417 | ||
b94cce92 HN |
418 | /* remove rp inst off the rprobe_inst_table */ |
419 | hlist_del(&ri->hlist); | |
ef53d9c5 S |
420 | INIT_HLIST_NODE(&ri->hlist); |
421 | if (likely(rp)) { | |
422 | spin_lock(&rp->lock); | |
423 | hlist_add_head(&ri->hlist, &rp->free_instances); | |
424 | spin_unlock(&rp->lock); | |
b94cce92 HN |
425 | } else |
426 | /* Unregistering */ | |
99219a3f | 427 | hlist_add_head(&ri->hlist, head); |
b94cce92 HN |
428 | } |
429 | ||
017c39bd | 430 | void __kprobes kretprobe_hash_lock(struct task_struct *tsk, |
ef53d9c5 S |
431 | struct hlist_head **head, unsigned long *flags) |
432 | { | |
433 | unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS); | |
434 | spinlock_t *hlist_lock; | |
435 | ||
436 | *head = &kretprobe_inst_table[hash]; | |
437 | hlist_lock = kretprobe_table_lock_ptr(hash); | |
438 | spin_lock_irqsave(hlist_lock, *flags); | |
439 | } | |
440 | ||
017c39bd MH |
441 | static void __kprobes kretprobe_table_lock(unsigned long hash, |
442 | unsigned long *flags) | |
b94cce92 | 443 | { |
ef53d9c5 S |
444 | spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash); |
445 | spin_lock_irqsave(hlist_lock, *flags); | |
446 | } | |
447 | ||
017c39bd MH |
448 | void __kprobes kretprobe_hash_unlock(struct task_struct *tsk, |
449 | unsigned long *flags) | |
ef53d9c5 S |
450 | { |
451 | unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS); | |
452 | spinlock_t *hlist_lock; | |
453 | ||
454 | hlist_lock = kretprobe_table_lock_ptr(hash); | |
455 | spin_unlock_irqrestore(hlist_lock, *flags); | |
456 | } | |
457 | ||
017c39bd | 458 | void __kprobes kretprobe_table_unlock(unsigned long hash, unsigned long *flags) |
ef53d9c5 S |
459 | { |
460 | spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash); | |
461 | spin_unlock_irqrestore(hlist_lock, *flags); | |
b94cce92 HN |
462 | } |
463 | ||
b94cce92 | 464 | /* |
c6fd91f0 | 465 | * This function is called from finish_task_switch when task tk becomes dead, |
466 | * so that we can recycle any function-return probe instances associated | |
467 | * with this task. These left over instances represent probed functions | |
468 | * that have been called but will never return. | |
b94cce92 | 469 | */ |
d0aaff97 | 470 | void __kprobes kprobe_flush_task(struct task_struct *tk) |
b94cce92 | 471 | { |
62c27be0 | 472 | struct kretprobe_instance *ri; |
99219a3f | 473 | struct hlist_head *head, empty_rp; |
802eae7c | 474 | struct hlist_node *node, *tmp; |
ef53d9c5 | 475 | unsigned long hash, flags = 0; |
802eae7c | 476 | |
ef53d9c5 S |
477 | if (unlikely(!kprobes_initialized)) |
478 | /* Early boot. kretprobe_table_locks not yet initialized. */ | |
479 | return; | |
480 | ||
481 | hash = hash_ptr(tk, KPROBE_HASH_BITS); | |
482 | head = &kretprobe_inst_table[hash]; | |
483 | kretprobe_table_lock(hash, &flags); | |
62c27be0 | 484 | hlist_for_each_entry_safe(ri, node, tmp, head, hlist) { |
485 | if (ri->task == tk) | |
99219a3f | 486 | recycle_rp_inst(ri, &empty_rp); |
62c27be0 | 487 | } |
ef53d9c5 S |
488 | kretprobe_table_unlock(hash, &flags); |
489 | INIT_HLIST_HEAD(&empty_rp); | |
99219a3f | 490 | hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) { |
491 | hlist_del(&ri->hlist); | |
492 | kfree(ri); | |
493 | } | |
b94cce92 HN |
494 | } |
495 | ||
b94cce92 HN |
496 | static inline void free_rp_inst(struct kretprobe *rp) |
497 | { | |
498 | struct kretprobe_instance *ri; | |
4c4308cb CH |
499 | struct hlist_node *pos, *next; |
500 | ||
ef53d9c5 S |
501 | hlist_for_each_entry_safe(ri, pos, next, &rp->free_instances, hlist) { |
502 | hlist_del(&ri->hlist); | |
b94cce92 HN |
503 | kfree(ri); |
504 | } | |
505 | } | |
506 | ||
4a296e07 MH |
507 | static void __kprobes cleanup_rp_inst(struct kretprobe *rp) |
508 | { | |
ef53d9c5 | 509 | unsigned long flags, hash; |
4a296e07 MH |
510 | struct kretprobe_instance *ri; |
511 | struct hlist_node *pos, *next; | |
ef53d9c5 S |
512 | struct hlist_head *head; |
513 | ||
4a296e07 | 514 | /* No race here */ |
ef53d9c5 S |
515 | for (hash = 0; hash < KPROBE_TABLE_SIZE; hash++) { |
516 | kretprobe_table_lock(hash, &flags); | |
517 | head = &kretprobe_inst_table[hash]; | |
518 | hlist_for_each_entry_safe(ri, pos, next, head, hlist) { | |
519 | if (ri->rp == rp) | |
520 | ri->rp = NULL; | |
521 | } | |
522 | kretprobe_table_unlock(hash, &flags); | |
4a296e07 | 523 | } |
4a296e07 MH |
524 | free_rp_inst(rp); |
525 | } | |
526 | ||
8b0914ea PP |
527 | /* |
528 | * Keep all fields in the kprobe consistent | |
529 | */ | |
530 | static inline void copy_kprobe(struct kprobe *old_p, struct kprobe *p) | |
531 | { | |
532 | memcpy(&p->opcode, &old_p->opcode, sizeof(kprobe_opcode_t)); | |
533 | memcpy(&p->ainsn, &old_p->ainsn, sizeof(struct arch_specific_insn)); | |
534 | } | |
535 | ||
536 | /* | |
b918e5e6 | 537 | * Add the new probe to ap->list. Fail if this is the |
8b0914ea PP |
538 | * second jprobe at the address - two jprobes can't coexist |
539 | */ | |
b918e5e6 | 540 | static int __kprobes add_new_kprobe(struct kprobe *ap, struct kprobe *p) |
8b0914ea | 541 | { |
de5bd88d | 542 | BUG_ON(kprobe_gone(ap) || kprobe_gone(p)); |
8b0914ea | 543 | if (p->break_handler) { |
b918e5e6 | 544 | if (ap->break_handler) |
36721656 | 545 | return -EEXIST; |
b918e5e6 MH |
546 | list_add_tail_rcu(&p->list, &ap->list); |
547 | ap->break_handler = aggr_break_handler; | |
8b0914ea | 548 | } else |
b918e5e6 MH |
549 | list_add_rcu(&p->list, &ap->list); |
550 | if (p->post_handler && !ap->post_handler) | |
551 | ap->post_handler = aggr_post_handler; | |
de5bd88d MH |
552 | |
553 | if (kprobe_disabled(ap) && !kprobe_disabled(p)) { | |
554 | ap->flags &= ~KPROBE_FLAG_DISABLED; | |
555 | if (!kprobes_all_disarmed) | |
556 | /* Arm the breakpoint again. */ | |
201517a7 | 557 | arm_kprobe(ap); |
de5bd88d | 558 | } |
8b0914ea PP |
559 | return 0; |
560 | } | |
561 | ||
64f562c6 AM |
562 | /* |
563 | * Fill in the required fields of the "manager kprobe". Replace the | |
564 | * earlier kprobe in the hlist with the manager kprobe | |
565 | */ | |
566 | static inline void add_aggr_kprobe(struct kprobe *ap, struct kprobe *p) | |
567 | { | |
8b0914ea | 568 | copy_kprobe(p, ap); |
a9ad965e | 569 | flush_insn_slot(ap); |
64f562c6 | 570 | ap->addr = p->addr; |
b918e5e6 | 571 | ap->flags = p->flags; |
64f562c6 | 572 | ap->pre_handler = aggr_pre_handler; |
64f562c6 | 573 | ap->fault_handler = aggr_fault_handler; |
e8386a0c MH |
574 | /* We don't care the kprobe which has gone. */ |
575 | if (p->post_handler && !kprobe_gone(p)) | |
36721656 | 576 | ap->post_handler = aggr_post_handler; |
e8386a0c | 577 | if (p->break_handler && !kprobe_gone(p)) |
36721656 | 578 | ap->break_handler = aggr_break_handler; |
64f562c6 AM |
579 | |
580 | INIT_LIST_HEAD(&ap->list); | |
3516a460 | 581 | list_add_rcu(&p->list, &ap->list); |
64f562c6 | 582 | |
adad0f33 | 583 | hlist_replace_rcu(&p->hlist, &ap->hlist); |
64f562c6 AM |
584 | } |
585 | ||
586 | /* | |
587 | * This is the second or subsequent kprobe at the address - handle | |
588 | * the intricacies | |
64f562c6 | 589 | */ |
d0aaff97 PP |
590 | static int __kprobes register_aggr_kprobe(struct kprobe *old_p, |
591 | struct kprobe *p) | |
64f562c6 AM |
592 | { |
593 | int ret = 0; | |
b918e5e6 | 594 | struct kprobe *ap = old_p; |
64f562c6 | 595 | |
b918e5e6 MH |
596 | if (old_p->pre_handler != aggr_pre_handler) { |
597 | /* If old_p is not an aggr_probe, create new aggr_kprobe. */ | |
598 | ap = kzalloc(sizeof(struct kprobe), GFP_KERNEL); | |
599 | if (!ap) | |
600 | return -ENOMEM; | |
601 | add_aggr_kprobe(ap, old_p); | |
602 | } | |
603 | ||
604 | if (kprobe_gone(ap)) { | |
e8386a0c MH |
605 | /* |
606 | * Attempting to insert new probe at the same location that | |
607 | * had a probe in the module vaddr area which already | |
608 | * freed. So, the instruction slot has already been | |
609 | * released. We need a new slot for the new probe. | |
610 | */ | |
b918e5e6 | 611 | ret = arch_prepare_kprobe(ap); |
e8386a0c | 612 | if (ret) |
b918e5e6 MH |
613 | /* |
614 | * Even if fail to allocate new slot, don't need to | |
615 | * free aggr_probe. It will be used next time, or | |
616 | * freed by unregister_kprobe. | |
617 | */ | |
e8386a0c | 618 | return ret; |
de5bd88d | 619 | |
e8386a0c | 620 | /* |
de5bd88d MH |
621 | * Clear gone flag to prevent allocating new slot again, and |
622 | * set disabled flag because it is not armed yet. | |
e8386a0c | 623 | */ |
de5bd88d MH |
624 | ap->flags = (ap->flags & ~KPROBE_FLAG_GONE) |
625 | | KPROBE_FLAG_DISABLED; | |
e8386a0c | 626 | } |
b918e5e6 MH |
627 | |
628 | copy_kprobe(ap, p); | |
629 | return add_new_kprobe(ap, p); | |
64f562c6 AM |
630 | } |
631 | ||
de5bd88d MH |
632 | /* Try to disable aggr_kprobe, and return 1 if succeeded.*/ |
633 | static int __kprobes try_to_disable_aggr_kprobe(struct kprobe *p) | |
634 | { | |
635 | struct kprobe *kp; | |
636 | ||
637 | list_for_each_entry_rcu(kp, &p->list, list) { | |
638 | if (!kprobe_disabled(kp)) | |
639 | /* | |
640 | * There is an active probe on the list. | |
641 | * We can't disable aggr_kprobe. | |
642 | */ | |
643 | return 0; | |
644 | } | |
645 | p->flags |= KPROBE_FLAG_DISABLED; | |
646 | return 1; | |
647 | } | |
648 | ||
d0aaff97 PP |
649 | static int __kprobes in_kprobes_functions(unsigned long addr) |
650 | { | |
3d8d996e SD |
651 | struct kprobe_blackpoint *kb; |
652 | ||
6f716acd CH |
653 | if (addr >= (unsigned long)__kprobes_text_start && |
654 | addr < (unsigned long)__kprobes_text_end) | |
d0aaff97 | 655 | return -EINVAL; |
3d8d996e SD |
656 | /* |
657 | * If there exists a kprobe_blacklist, verify and | |
658 | * fail any probe registration in the prohibited area | |
659 | */ | |
660 | for (kb = kprobe_blacklist; kb->name != NULL; kb++) { | |
661 | if (kb->start_addr) { | |
662 | if (addr >= kb->start_addr && | |
663 | addr < (kb->start_addr + kb->range)) | |
664 | return -EINVAL; | |
665 | } | |
666 | } | |
d0aaff97 PP |
667 | return 0; |
668 | } | |
669 | ||
b2a5cd69 MH |
670 | /* |
671 | * If we have a symbol_name argument, look it up and add the offset field | |
672 | * to it. This way, we can specify a relative address to a symbol. | |
673 | */ | |
674 | static kprobe_opcode_t __kprobes *kprobe_addr(struct kprobe *p) | |
675 | { | |
676 | kprobe_opcode_t *addr = p->addr; | |
677 | if (p->symbol_name) { | |
678 | if (addr) | |
679 | return NULL; | |
680 | kprobe_lookup_name(p->symbol_name, addr); | |
681 | } | |
682 | ||
683 | if (!addr) | |
684 | return NULL; | |
685 | return (kprobe_opcode_t *)(((char *)addr) + p->offset); | |
686 | } | |
687 | ||
49ad2fd7 | 688 | int __kprobes register_kprobe(struct kprobe *p) |
1da177e4 LT |
689 | { |
690 | int ret = 0; | |
64f562c6 | 691 | struct kprobe *old_p; |
df019b1d | 692 | struct module *probed_mod; |
b2a5cd69 | 693 | kprobe_opcode_t *addr; |
b3e55c72 | 694 | |
b2a5cd69 MH |
695 | addr = kprobe_addr(p); |
696 | if (!addr) | |
3a872d89 | 697 | return -EINVAL; |
b2a5cd69 | 698 | p->addr = addr; |
3a872d89 | 699 | |
a189d035 MH |
700 | preempt_disable(); |
701 | if (!__kernel_text_address((unsigned long) p->addr) || | |
702 | in_kprobes_functions((unsigned long) p->addr)) { | |
703 | preempt_enable(); | |
b3e55c72 | 704 | return -EINVAL; |
a189d035 | 705 | } |
b3e55c72 | 706 | |
de5bd88d MH |
707 | /* User can pass only KPROBE_FLAG_DISABLED to register_kprobe */ |
708 | p->flags &= KPROBE_FLAG_DISABLED; | |
709 | ||
6f716acd CH |
710 | /* |
711 | * Check if are we probing a module. | |
712 | */ | |
a189d035 | 713 | probed_mod = __module_text_address((unsigned long) p->addr); |
6f716acd | 714 | if (probed_mod) { |
6f716acd | 715 | /* |
e8386a0c MH |
716 | * We must hold a refcount of the probed module while updating |
717 | * its code to prohibit unexpected unloading. | |
df019b1d | 718 | */ |
49ad2fd7 MH |
719 | if (unlikely(!try_module_get(probed_mod))) { |
720 | preempt_enable(); | |
721 | return -EINVAL; | |
722 | } | |
f24659d9 MH |
723 | /* |
724 | * If the module freed .init.text, we couldn't insert | |
725 | * kprobes in there. | |
726 | */ | |
727 | if (within_module_init((unsigned long)p->addr, probed_mod) && | |
728 | probed_mod->state != MODULE_STATE_COMING) { | |
729 | module_put(probed_mod); | |
730 | preempt_enable(); | |
731 | return -EINVAL; | |
732 | } | |
df019b1d | 733 | } |
a189d035 | 734 | preempt_enable(); |
1da177e4 | 735 | |
3516a460 | 736 | p->nmissed = 0; |
9861668f | 737 | INIT_LIST_HEAD(&p->list); |
7a7d1cf9 | 738 | mutex_lock(&kprobe_mutex); |
64f562c6 AM |
739 | old_p = get_kprobe(p->addr); |
740 | if (old_p) { | |
741 | ret = register_aggr_kprobe(old_p, p); | |
1da177e4 LT |
742 | goto out; |
743 | } | |
1da177e4 | 744 | |
4460fdad | 745 | mutex_lock(&text_mutex); |
6f716acd CH |
746 | ret = arch_prepare_kprobe(p); |
747 | if (ret) | |
4460fdad | 748 | goto out_unlock_text; |
49a2a1b8 | 749 | |
64f562c6 | 750 | INIT_HLIST_NODE(&p->hlist); |
3516a460 | 751 | hlist_add_head_rcu(&p->hlist, |
1da177e4 LT |
752 | &kprobe_table[hash_ptr(p->addr, KPROBE_HASH_BITS)]); |
753 | ||
de5bd88d | 754 | if (!kprobes_all_disarmed && !kprobe_disabled(p)) |
bf8f6e5b | 755 | arch_arm_kprobe(p); |
74a0b576 | 756 | |
4460fdad MD |
757 | out_unlock_text: |
758 | mutex_unlock(&text_mutex); | |
1da177e4 | 759 | out: |
7a7d1cf9 | 760 | mutex_unlock(&kprobe_mutex); |
49a2a1b8 | 761 | |
e8386a0c | 762 | if (probed_mod) |
df019b1d | 763 | module_put(probed_mod); |
e8386a0c | 764 | |
1da177e4 LT |
765 | return ret; |
766 | } | |
99081ab5 | 767 | EXPORT_SYMBOL_GPL(register_kprobe); |
1da177e4 | 768 | |
de5bd88d MH |
769 | /* Check passed kprobe is valid and return kprobe in kprobe_table. */ |
770 | static struct kprobe * __kprobes __get_valid_kprobe(struct kprobe *p) | |
1da177e4 | 771 | { |
f709b122 | 772 | struct kprobe *old_p, *list_p; |
64f562c6 | 773 | |
64f562c6 | 774 | old_p = get_kprobe(p->addr); |
9861668f | 775 | if (unlikely(!old_p)) |
de5bd88d | 776 | return NULL; |
9861668f | 777 | |
f709b122 KA |
778 | if (p != old_p) { |
779 | list_for_each_entry_rcu(list_p, &old_p->list, list) | |
780 | if (list_p == p) | |
781 | /* kprobe p is a valid probe */ | |
de5bd88d MH |
782 | goto valid; |
783 | return NULL; | |
f709b122 | 784 | } |
de5bd88d MH |
785 | valid: |
786 | return old_p; | |
787 | } | |
788 | ||
789 | /* | |
790 | * Unregister a kprobe without a scheduler synchronization. | |
791 | */ | |
792 | static int __kprobes __unregister_kprobe_top(struct kprobe *p) | |
793 | { | |
794 | struct kprobe *old_p, *list_p; | |
795 | ||
796 | old_p = __get_valid_kprobe(p); | |
797 | if (old_p == NULL) | |
798 | return -EINVAL; | |
799 | ||
6f716acd CH |
800 | if (old_p == p || |
801 | (old_p->pre_handler == aggr_pre_handler && | |
9861668f | 802 | list_is_singular(&old_p->list))) { |
bf8f6e5b AM |
803 | /* |
804 | * Only probe on the hash list. Disarm only if kprobes are | |
e8386a0c MH |
805 | * enabled and not gone - otherwise, the breakpoint would |
806 | * already have been removed. We save on flushing icache. | |
bf8f6e5b | 807 | */ |
201517a7 MH |
808 | if (!kprobes_all_disarmed && !kprobe_disabled(old_p)) |
809 | disarm_kprobe(p); | |
49a2a1b8 | 810 | hlist_del_rcu(&old_p->hlist); |
49a2a1b8 | 811 | } else { |
e8386a0c | 812 | if (p->break_handler && !kprobe_gone(p)) |
9861668f | 813 | old_p->break_handler = NULL; |
e8386a0c | 814 | if (p->post_handler && !kprobe_gone(p)) { |
9861668f MH |
815 | list_for_each_entry_rcu(list_p, &old_p->list, list) { |
816 | if ((list_p != p) && (list_p->post_handler)) | |
817 | goto noclean; | |
818 | } | |
819 | old_p->post_handler = NULL; | |
820 | } | |
821 | noclean: | |
49a2a1b8 | 822 | list_del_rcu(&p->list); |
de5bd88d MH |
823 | if (!kprobe_disabled(old_p)) { |
824 | try_to_disable_aggr_kprobe(old_p); | |
825 | if (!kprobes_all_disarmed && kprobe_disabled(old_p)) | |
201517a7 | 826 | disarm_kprobe(old_p); |
de5bd88d | 827 | } |
49a2a1b8 | 828 | } |
9861668f MH |
829 | return 0; |
830 | } | |
3516a460 | 831 | |
9861668f MH |
832 | static void __kprobes __unregister_kprobe_bottom(struct kprobe *p) |
833 | { | |
9861668f | 834 | struct kprobe *old_p; |
b3e55c72 | 835 | |
e8386a0c | 836 | if (list_empty(&p->list)) |
0498b635 | 837 | arch_remove_kprobe(p); |
e8386a0c MH |
838 | else if (list_is_singular(&p->list)) { |
839 | /* "p" is the last child of an aggr_kprobe */ | |
840 | old_p = list_entry(p->list.next, struct kprobe, list); | |
841 | list_del(&p->list); | |
842 | arch_remove_kprobe(old_p); | |
843 | kfree(old_p); | |
9861668f MH |
844 | } |
845 | } | |
846 | ||
49ad2fd7 | 847 | int __kprobes register_kprobes(struct kprobe **kps, int num) |
9861668f MH |
848 | { |
849 | int i, ret = 0; | |
850 | ||
851 | if (num <= 0) | |
852 | return -EINVAL; | |
853 | for (i = 0; i < num; i++) { | |
49ad2fd7 | 854 | ret = register_kprobe(kps[i]); |
67dddaad MH |
855 | if (ret < 0) { |
856 | if (i > 0) | |
857 | unregister_kprobes(kps, i); | |
9861668f | 858 | break; |
36721656 | 859 | } |
49a2a1b8 | 860 | } |
9861668f MH |
861 | return ret; |
862 | } | |
99081ab5 | 863 | EXPORT_SYMBOL_GPL(register_kprobes); |
9861668f | 864 | |
9861668f MH |
865 | void __kprobes unregister_kprobe(struct kprobe *p) |
866 | { | |
867 | unregister_kprobes(&p, 1); | |
868 | } | |
99081ab5 | 869 | EXPORT_SYMBOL_GPL(unregister_kprobe); |
9861668f | 870 | |
9861668f MH |
871 | void __kprobes unregister_kprobes(struct kprobe **kps, int num) |
872 | { | |
873 | int i; | |
874 | ||
875 | if (num <= 0) | |
876 | return; | |
877 | mutex_lock(&kprobe_mutex); | |
878 | for (i = 0; i < num; i++) | |
879 | if (__unregister_kprobe_top(kps[i]) < 0) | |
880 | kps[i]->addr = NULL; | |
881 | mutex_unlock(&kprobe_mutex); | |
882 | ||
883 | synchronize_sched(); | |
884 | for (i = 0; i < num; i++) | |
885 | if (kps[i]->addr) | |
886 | __unregister_kprobe_bottom(kps[i]); | |
1da177e4 | 887 | } |
99081ab5 | 888 | EXPORT_SYMBOL_GPL(unregister_kprobes); |
1da177e4 LT |
889 | |
890 | static struct notifier_block kprobe_exceptions_nb = { | |
3d5631e0 AK |
891 | .notifier_call = kprobe_exceptions_notify, |
892 | .priority = 0x7fffffff /* we need to be notified first */ | |
893 | }; | |
894 | ||
3d7e3382 ME |
895 | unsigned long __weak arch_deref_entry_point(void *entry) |
896 | { | |
897 | return (unsigned long)entry; | |
898 | } | |
1da177e4 | 899 | |
49ad2fd7 | 900 | int __kprobes register_jprobes(struct jprobe **jps, int num) |
1da177e4 | 901 | { |
26b31c19 MH |
902 | struct jprobe *jp; |
903 | int ret = 0, i; | |
3d7e3382 | 904 | |
26b31c19 | 905 | if (num <= 0) |
3d7e3382 | 906 | return -EINVAL; |
26b31c19 MH |
907 | for (i = 0; i < num; i++) { |
908 | unsigned long addr; | |
909 | jp = jps[i]; | |
910 | addr = arch_deref_entry_point(jp->entry); | |
911 | ||
912 | if (!kernel_text_address(addr)) | |
913 | ret = -EINVAL; | |
914 | else { | |
915 | /* Todo: Verify probepoint is a function entry point */ | |
916 | jp->kp.pre_handler = setjmp_pre_handler; | |
917 | jp->kp.break_handler = longjmp_break_handler; | |
49ad2fd7 | 918 | ret = register_kprobe(&jp->kp); |
26b31c19 | 919 | } |
67dddaad MH |
920 | if (ret < 0) { |
921 | if (i > 0) | |
922 | unregister_jprobes(jps, i); | |
26b31c19 MH |
923 | break; |
924 | } | |
925 | } | |
926 | return ret; | |
927 | } | |
99081ab5 | 928 | EXPORT_SYMBOL_GPL(register_jprobes); |
3d7e3382 | 929 | |
26b31c19 MH |
930 | int __kprobes register_jprobe(struct jprobe *jp) |
931 | { | |
49ad2fd7 | 932 | return register_jprobes(&jp, 1); |
1da177e4 | 933 | } |
99081ab5 | 934 | EXPORT_SYMBOL_GPL(register_jprobe); |
1da177e4 | 935 | |
d0aaff97 | 936 | void __kprobes unregister_jprobe(struct jprobe *jp) |
1da177e4 | 937 | { |
26b31c19 MH |
938 | unregister_jprobes(&jp, 1); |
939 | } | |
99081ab5 | 940 | EXPORT_SYMBOL_GPL(unregister_jprobe); |
26b31c19 | 941 | |
26b31c19 MH |
942 | void __kprobes unregister_jprobes(struct jprobe **jps, int num) |
943 | { | |
944 | int i; | |
945 | ||
946 | if (num <= 0) | |
947 | return; | |
948 | mutex_lock(&kprobe_mutex); | |
949 | for (i = 0; i < num; i++) | |
950 | if (__unregister_kprobe_top(&jps[i]->kp) < 0) | |
951 | jps[i]->kp.addr = NULL; | |
952 | mutex_unlock(&kprobe_mutex); | |
953 | ||
954 | synchronize_sched(); | |
955 | for (i = 0; i < num; i++) { | |
956 | if (jps[i]->kp.addr) | |
957 | __unregister_kprobe_bottom(&jps[i]->kp); | |
958 | } | |
1da177e4 | 959 | } |
99081ab5 | 960 | EXPORT_SYMBOL_GPL(unregister_jprobes); |
1da177e4 | 961 | |
9edddaa2 | 962 | #ifdef CONFIG_KRETPROBES |
e65cefe8 AB |
963 | /* |
964 | * This kprobe pre_handler is registered with every kretprobe. When probe | |
965 | * hits it will set up the return probe. | |
966 | */ | |
967 | static int __kprobes pre_handler_kretprobe(struct kprobe *p, | |
968 | struct pt_regs *regs) | |
969 | { | |
970 | struct kretprobe *rp = container_of(p, struct kretprobe, kp); | |
ef53d9c5 S |
971 | unsigned long hash, flags = 0; |
972 | struct kretprobe_instance *ri; | |
e65cefe8 AB |
973 | |
974 | /*TODO: consider to only swap the RA after the last pre_handler fired */ | |
ef53d9c5 S |
975 | hash = hash_ptr(current, KPROBE_HASH_BITS); |
976 | spin_lock_irqsave(&rp->lock, flags); | |
4c4308cb | 977 | if (!hlist_empty(&rp->free_instances)) { |
4c4308cb | 978 | ri = hlist_entry(rp->free_instances.first, |
ef53d9c5 S |
979 | struct kretprobe_instance, hlist); |
980 | hlist_del(&ri->hlist); | |
981 | spin_unlock_irqrestore(&rp->lock, flags); | |
982 | ||
4c4308cb CH |
983 | ri->rp = rp; |
984 | ri->task = current; | |
f47cd9b5 | 985 | |
f02b8624 | 986 | if (rp->entry_handler && rp->entry_handler(ri, regs)) |
f47cd9b5 | 987 | return 0; |
f47cd9b5 | 988 | |
4c4308cb CH |
989 | arch_prepare_kretprobe(ri, regs); |
990 | ||
991 | /* XXX(hch): why is there no hlist_move_head? */ | |
ef53d9c5 S |
992 | INIT_HLIST_NODE(&ri->hlist); |
993 | kretprobe_table_lock(hash, &flags); | |
994 | hlist_add_head(&ri->hlist, &kretprobe_inst_table[hash]); | |
995 | kretprobe_table_unlock(hash, &flags); | |
996 | } else { | |
4c4308cb | 997 | rp->nmissed++; |
ef53d9c5 S |
998 | spin_unlock_irqrestore(&rp->lock, flags); |
999 | } | |
e65cefe8 AB |
1000 | return 0; |
1001 | } | |
1002 | ||
49ad2fd7 | 1003 | int __kprobes register_kretprobe(struct kretprobe *rp) |
b94cce92 HN |
1004 | { |
1005 | int ret = 0; | |
1006 | struct kretprobe_instance *inst; | |
1007 | int i; | |
b2a5cd69 | 1008 | void *addr; |
f438d914 MH |
1009 | |
1010 | if (kretprobe_blacklist_size) { | |
b2a5cd69 MH |
1011 | addr = kprobe_addr(&rp->kp); |
1012 | if (!addr) | |
1013 | return -EINVAL; | |
f438d914 MH |
1014 | |
1015 | for (i = 0; kretprobe_blacklist[i].name != NULL; i++) { | |
1016 | if (kretprobe_blacklist[i].addr == addr) | |
1017 | return -EINVAL; | |
1018 | } | |
1019 | } | |
b94cce92 HN |
1020 | |
1021 | rp->kp.pre_handler = pre_handler_kretprobe; | |
7522a842 AM |
1022 | rp->kp.post_handler = NULL; |
1023 | rp->kp.fault_handler = NULL; | |
1024 | rp->kp.break_handler = NULL; | |
b94cce92 HN |
1025 | |
1026 | /* Pre-allocate memory for max kretprobe instances */ | |
1027 | if (rp->maxactive <= 0) { | |
1028 | #ifdef CONFIG_PREEMPT | |
1029 | rp->maxactive = max(10, 2 * NR_CPUS); | |
1030 | #else | |
1031 | rp->maxactive = NR_CPUS; | |
1032 | #endif | |
1033 | } | |
ef53d9c5 | 1034 | spin_lock_init(&rp->lock); |
b94cce92 HN |
1035 | INIT_HLIST_HEAD(&rp->free_instances); |
1036 | for (i = 0; i < rp->maxactive; i++) { | |
f47cd9b5 AS |
1037 | inst = kmalloc(sizeof(struct kretprobe_instance) + |
1038 | rp->data_size, GFP_KERNEL); | |
b94cce92 HN |
1039 | if (inst == NULL) { |
1040 | free_rp_inst(rp); | |
1041 | return -ENOMEM; | |
1042 | } | |
ef53d9c5 S |
1043 | INIT_HLIST_NODE(&inst->hlist); |
1044 | hlist_add_head(&inst->hlist, &rp->free_instances); | |
b94cce92 HN |
1045 | } |
1046 | ||
1047 | rp->nmissed = 0; | |
1048 | /* Establish function entry probe point */ | |
49ad2fd7 | 1049 | ret = register_kprobe(&rp->kp); |
4a296e07 | 1050 | if (ret != 0) |
b94cce92 HN |
1051 | free_rp_inst(rp); |
1052 | return ret; | |
1053 | } | |
99081ab5 | 1054 | EXPORT_SYMBOL_GPL(register_kretprobe); |
b94cce92 | 1055 | |
49ad2fd7 | 1056 | int __kprobes register_kretprobes(struct kretprobe **rps, int num) |
4a296e07 MH |
1057 | { |
1058 | int ret = 0, i; | |
1059 | ||
1060 | if (num <= 0) | |
1061 | return -EINVAL; | |
1062 | for (i = 0; i < num; i++) { | |
49ad2fd7 | 1063 | ret = register_kretprobe(rps[i]); |
67dddaad MH |
1064 | if (ret < 0) { |
1065 | if (i > 0) | |
1066 | unregister_kretprobes(rps, i); | |
4a296e07 MH |
1067 | break; |
1068 | } | |
1069 | } | |
1070 | return ret; | |
1071 | } | |
99081ab5 | 1072 | EXPORT_SYMBOL_GPL(register_kretprobes); |
4a296e07 | 1073 | |
4a296e07 MH |
1074 | void __kprobes unregister_kretprobe(struct kretprobe *rp) |
1075 | { | |
1076 | unregister_kretprobes(&rp, 1); | |
1077 | } | |
99081ab5 | 1078 | EXPORT_SYMBOL_GPL(unregister_kretprobe); |
4a296e07 | 1079 | |
4a296e07 MH |
1080 | void __kprobes unregister_kretprobes(struct kretprobe **rps, int num) |
1081 | { | |
1082 | int i; | |
1083 | ||
1084 | if (num <= 0) | |
1085 | return; | |
1086 | mutex_lock(&kprobe_mutex); | |
1087 | for (i = 0; i < num; i++) | |
1088 | if (__unregister_kprobe_top(&rps[i]->kp) < 0) | |
1089 | rps[i]->kp.addr = NULL; | |
1090 | mutex_unlock(&kprobe_mutex); | |
1091 | ||
1092 | synchronize_sched(); | |
1093 | for (i = 0; i < num; i++) { | |
1094 | if (rps[i]->kp.addr) { | |
1095 | __unregister_kprobe_bottom(&rps[i]->kp); | |
1096 | cleanup_rp_inst(rps[i]); | |
1097 | } | |
1098 | } | |
1099 | } | |
99081ab5 | 1100 | EXPORT_SYMBOL_GPL(unregister_kretprobes); |
4a296e07 | 1101 | |
9edddaa2 | 1102 | #else /* CONFIG_KRETPROBES */ |
d0aaff97 | 1103 | int __kprobes register_kretprobe(struct kretprobe *rp) |
b94cce92 HN |
1104 | { |
1105 | return -ENOSYS; | |
1106 | } | |
99081ab5 | 1107 | EXPORT_SYMBOL_GPL(register_kretprobe); |
b94cce92 | 1108 | |
4a296e07 | 1109 | int __kprobes register_kretprobes(struct kretprobe **rps, int num) |
346fd59b | 1110 | { |
4a296e07 | 1111 | return -ENOSYS; |
346fd59b | 1112 | } |
99081ab5 MH |
1113 | EXPORT_SYMBOL_GPL(register_kretprobes); |
1114 | ||
d0aaff97 | 1115 | void __kprobes unregister_kretprobe(struct kretprobe *rp) |
b94cce92 | 1116 | { |
4a296e07 | 1117 | } |
99081ab5 | 1118 | EXPORT_SYMBOL_GPL(unregister_kretprobe); |
b94cce92 | 1119 | |
4a296e07 MH |
1120 | void __kprobes unregister_kretprobes(struct kretprobe **rps, int num) |
1121 | { | |
1122 | } | |
99081ab5 | 1123 | EXPORT_SYMBOL_GPL(unregister_kretprobes); |
4c4308cb | 1124 | |
4a296e07 MH |
1125 | static int __kprobes pre_handler_kretprobe(struct kprobe *p, |
1126 | struct pt_regs *regs) | |
1127 | { | |
1128 | return 0; | |
b94cce92 HN |
1129 | } |
1130 | ||
4a296e07 MH |
1131 | #endif /* CONFIG_KRETPROBES */ |
1132 | ||
e8386a0c MH |
1133 | /* Set the kprobe gone and remove its instruction buffer. */ |
1134 | static void __kprobes kill_kprobe(struct kprobe *p) | |
1135 | { | |
1136 | struct kprobe *kp; | |
de5bd88d | 1137 | |
e8386a0c MH |
1138 | p->flags |= KPROBE_FLAG_GONE; |
1139 | if (p->pre_handler == aggr_pre_handler) { | |
1140 | /* | |
1141 | * If this is an aggr_kprobe, we have to list all the | |
1142 | * chained probes and mark them GONE. | |
1143 | */ | |
1144 | list_for_each_entry_rcu(kp, &p->list, list) | |
1145 | kp->flags |= KPROBE_FLAG_GONE; | |
1146 | p->post_handler = NULL; | |
1147 | p->break_handler = NULL; | |
1148 | } | |
1149 | /* | |
1150 | * Here, we can remove insn_slot safely, because no thread calls | |
1151 | * the original probed function (which will be freed soon) any more. | |
1152 | */ | |
1153 | arch_remove_kprobe(p); | |
1154 | } | |
1155 | ||
1156 | /* Module notifier call back, checking kprobes on the module */ | |
1157 | static int __kprobes kprobes_module_callback(struct notifier_block *nb, | |
1158 | unsigned long val, void *data) | |
1159 | { | |
1160 | struct module *mod = data; | |
1161 | struct hlist_head *head; | |
1162 | struct hlist_node *node; | |
1163 | struct kprobe *p; | |
1164 | unsigned int i; | |
f24659d9 | 1165 | int checkcore = (val == MODULE_STATE_GOING); |
e8386a0c | 1166 | |
f24659d9 | 1167 | if (val != MODULE_STATE_GOING && val != MODULE_STATE_LIVE) |
e8386a0c MH |
1168 | return NOTIFY_DONE; |
1169 | ||
1170 | /* | |
f24659d9 MH |
1171 | * When MODULE_STATE_GOING was notified, both of module .text and |
1172 | * .init.text sections would be freed. When MODULE_STATE_LIVE was | |
1173 | * notified, only .init.text section would be freed. We need to | |
1174 | * disable kprobes which have been inserted in the sections. | |
e8386a0c MH |
1175 | */ |
1176 | mutex_lock(&kprobe_mutex); | |
1177 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { | |
1178 | head = &kprobe_table[i]; | |
1179 | hlist_for_each_entry_rcu(p, node, head, hlist) | |
f24659d9 MH |
1180 | if (within_module_init((unsigned long)p->addr, mod) || |
1181 | (checkcore && | |
1182 | within_module_core((unsigned long)p->addr, mod))) { | |
e8386a0c MH |
1183 | /* |
1184 | * The vaddr this probe is installed will soon | |
1185 | * be vfreed buy not synced to disk. Hence, | |
1186 | * disarming the breakpoint isn't needed. | |
1187 | */ | |
1188 | kill_kprobe(p); | |
1189 | } | |
1190 | } | |
1191 | mutex_unlock(&kprobe_mutex); | |
1192 | return NOTIFY_DONE; | |
1193 | } | |
1194 | ||
1195 | static struct notifier_block kprobe_module_nb = { | |
1196 | .notifier_call = kprobes_module_callback, | |
1197 | .priority = 0 | |
1198 | }; | |
1199 | ||
1da177e4 LT |
1200 | static int __init init_kprobes(void) |
1201 | { | |
1202 | int i, err = 0; | |
3d8d996e SD |
1203 | unsigned long offset = 0, size = 0; |
1204 | char *modname, namebuf[128]; | |
1205 | const char *symbol_name; | |
1206 | void *addr; | |
1207 | struct kprobe_blackpoint *kb; | |
1da177e4 LT |
1208 | |
1209 | /* FIXME allocate the probe table, currently defined statically */ | |
1210 | /* initialize all list heads */ | |
b94cce92 | 1211 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
1da177e4 | 1212 | INIT_HLIST_HEAD(&kprobe_table[i]); |
b94cce92 | 1213 | INIT_HLIST_HEAD(&kretprobe_inst_table[i]); |
ef53d9c5 | 1214 | spin_lock_init(&(kretprobe_table_locks[i].lock)); |
b94cce92 | 1215 | } |
1da177e4 | 1216 | |
3d8d996e SD |
1217 | /* |
1218 | * Lookup and populate the kprobe_blacklist. | |
1219 | * | |
1220 | * Unlike the kretprobe blacklist, we'll need to determine | |
1221 | * the range of addresses that belong to the said functions, | |
1222 | * since a kprobe need not necessarily be at the beginning | |
1223 | * of a function. | |
1224 | */ | |
1225 | for (kb = kprobe_blacklist; kb->name != NULL; kb++) { | |
1226 | kprobe_lookup_name(kb->name, addr); | |
1227 | if (!addr) | |
1228 | continue; | |
1229 | ||
1230 | kb->start_addr = (unsigned long)addr; | |
1231 | symbol_name = kallsyms_lookup(kb->start_addr, | |
1232 | &size, &offset, &modname, namebuf); | |
1233 | if (!symbol_name) | |
1234 | kb->range = 0; | |
1235 | else | |
1236 | kb->range = size; | |
1237 | } | |
1238 | ||
f438d914 MH |
1239 | if (kretprobe_blacklist_size) { |
1240 | /* lookup the function address from its name */ | |
1241 | for (i = 0; kretprobe_blacklist[i].name != NULL; i++) { | |
1242 | kprobe_lookup_name(kretprobe_blacklist[i].name, | |
1243 | kretprobe_blacklist[i].addr); | |
1244 | if (!kretprobe_blacklist[i].addr) | |
1245 | printk("kretprobe: lookup failed: %s\n", | |
1246 | kretprobe_blacklist[i].name); | |
1247 | } | |
1248 | } | |
1249 | ||
e579abeb MH |
1250 | /* By default, kprobes are armed */ |
1251 | kprobes_all_disarmed = false; | |
bf8f6e5b | 1252 | |
6772926b | 1253 | err = arch_init_kprobes(); |
802eae7c RL |
1254 | if (!err) |
1255 | err = register_die_notifier(&kprobe_exceptions_nb); | |
e8386a0c MH |
1256 | if (!err) |
1257 | err = register_module_notifier(&kprobe_module_nb); | |
1258 | ||
ef53d9c5 | 1259 | kprobes_initialized = (err == 0); |
802eae7c | 1260 | |
8c1c9356 AM |
1261 | if (!err) |
1262 | init_test_probes(); | |
1da177e4 LT |
1263 | return err; |
1264 | } | |
1265 | ||
346fd59b SD |
1266 | #ifdef CONFIG_DEBUG_FS |
1267 | static void __kprobes report_probe(struct seq_file *pi, struct kprobe *p, | |
bf8f6e5b | 1268 | const char *sym, int offset,char *modname) |
346fd59b SD |
1269 | { |
1270 | char *kprobe_type; | |
1271 | ||
1272 | if (p->pre_handler == pre_handler_kretprobe) | |
1273 | kprobe_type = "r"; | |
1274 | else if (p->pre_handler == setjmp_pre_handler) | |
1275 | kprobe_type = "j"; | |
1276 | else | |
1277 | kprobe_type = "k"; | |
1278 | if (sym) | |
de5bd88d MH |
1279 | seq_printf(pi, "%p %s %s+0x%x %s %s%s\n", |
1280 | p->addr, kprobe_type, sym, offset, | |
1281 | (modname ? modname : " "), | |
1282 | (kprobe_gone(p) ? "[GONE]" : ""), | |
1283 | ((kprobe_disabled(p) && !kprobe_gone(p)) ? | |
1284 | "[DISABLED]" : "")); | |
346fd59b | 1285 | else |
de5bd88d MH |
1286 | seq_printf(pi, "%p %s %p %s%s\n", |
1287 | p->addr, kprobe_type, p->addr, | |
1288 | (kprobe_gone(p) ? "[GONE]" : ""), | |
1289 | ((kprobe_disabled(p) && !kprobe_gone(p)) ? | |
1290 | "[DISABLED]" : "")); | |
346fd59b SD |
1291 | } |
1292 | ||
1293 | static void __kprobes *kprobe_seq_start(struct seq_file *f, loff_t *pos) | |
1294 | { | |
1295 | return (*pos < KPROBE_TABLE_SIZE) ? pos : NULL; | |
1296 | } | |
1297 | ||
1298 | static void __kprobes *kprobe_seq_next(struct seq_file *f, void *v, loff_t *pos) | |
1299 | { | |
1300 | (*pos)++; | |
1301 | if (*pos >= KPROBE_TABLE_SIZE) | |
1302 | return NULL; | |
1303 | return pos; | |
1304 | } | |
1305 | ||
1306 | static void __kprobes kprobe_seq_stop(struct seq_file *f, void *v) | |
1307 | { | |
1308 | /* Nothing to do */ | |
1309 | } | |
1310 | ||
1311 | static int __kprobes show_kprobe_addr(struct seq_file *pi, void *v) | |
1312 | { | |
1313 | struct hlist_head *head; | |
1314 | struct hlist_node *node; | |
1315 | struct kprobe *p, *kp; | |
1316 | const char *sym = NULL; | |
1317 | unsigned int i = *(loff_t *) v; | |
ffb45122 | 1318 | unsigned long offset = 0; |
346fd59b SD |
1319 | char *modname, namebuf[128]; |
1320 | ||
1321 | head = &kprobe_table[i]; | |
1322 | preempt_disable(); | |
1323 | hlist_for_each_entry_rcu(p, node, head, hlist) { | |
ffb45122 | 1324 | sym = kallsyms_lookup((unsigned long)p->addr, NULL, |
346fd59b SD |
1325 | &offset, &modname, namebuf); |
1326 | if (p->pre_handler == aggr_pre_handler) { | |
1327 | list_for_each_entry_rcu(kp, &p->list, list) | |
1328 | report_probe(pi, kp, sym, offset, modname); | |
1329 | } else | |
1330 | report_probe(pi, p, sym, offset, modname); | |
1331 | } | |
1332 | preempt_enable(); | |
1333 | return 0; | |
1334 | } | |
1335 | ||
1336 | static struct seq_operations kprobes_seq_ops = { | |
1337 | .start = kprobe_seq_start, | |
1338 | .next = kprobe_seq_next, | |
1339 | .stop = kprobe_seq_stop, | |
1340 | .show = show_kprobe_addr | |
1341 | }; | |
1342 | ||
1343 | static int __kprobes kprobes_open(struct inode *inode, struct file *filp) | |
1344 | { | |
1345 | return seq_open(filp, &kprobes_seq_ops); | |
1346 | } | |
1347 | ||
1348 | static struct file_operations debugfs_kprobes_operations = { | |
1349 | .open = kprobes_open, | |
1350 | .read = seq_read, | |
1351 | .llseek = seq_lseek, | |
1352 | .release = seq_release, | |
1353 | }; | |
1354 | ||
de5bd88d MH |
1355 | /* Disable one kprobe */ |
1356 | int __kprobes disable_kprobe(struct kprobe *kp) | |
1357 | { | |
1358 | int ret = 0; | |
1359 | struct kprobe *p; | |
1360 | ||
1361 | mutex_lock(&kprobe_mutex); | |
1362 | ||
1363 | /* Check whether specified probe is valid. */ | |
1364 | p = __get_valid_kprobe(kp); | |
1365 | if (unlikely(p == NULL)) { | |
1366 | ret = -EINVAL; | |
1367 | goto out; | |
1368 | } | |
1369 | ||
1370 | /* If the probe is already disabled (or gone), just return */ | |
1371 | if (kprobe_disabled(kp)) | |
1372 | goto out; | |
1373 | ||
1374 | kp->flags |= KPROBE_FLAG_DISABLED; | |
1375 | if (p != kp) | |
1376 | /* When kp != p, p is always enabled. */ | |
1377 | try_to_disable_aggr_kprobe(p); | |
1378 | ||
1379 | if (!kprobes_all_disarmed && kprobe_disabled(p)) | |
201517a7 | 1380 | disarm_kprobe(p); |
de5bd88d MH |
1381 | out: |
1382 | mutex_unlock(&kprobe_mutex); | |
1383 | return ret; | |
1384 | } | |
1385 | EXPORT_SYMBOL_GPL(disable_kprobe); | |
1386 | ||
1387 | /* Enable one kprobe */ | |
1388 | int __kprobes enable_kprobe(struct kprobe *kp) | |
1389 | { | |
1390 | int ret = 0; | |
1391 | struct kprobe *p; | |
1392 | ||
1393 | mutex_lock(&kprobe_mutex); | |
1394 | ||
1395 | /* Check whether specified probe is valid. */ | |
1396 | p = __get_valid_kprobe(kp); | |
1397 | if (unlikely(p == NULL)) { | |
1398 | ret = -EINVAL; | |
1399 | goto out; | |
1400 | } | |
1401 | ||
1402 | if (kprobe_gone(kp)) { | |
1403 | /* This kprobe has gone, we couldn't enable it. */ | |
1404 | ret = -EINVAL; | |
1405 | goto out; | |
1406 | } | |
1407 | ||
1408 | if (!kprobes_all_disarmed && kprobe_disabled(p)) | |
201517a7 | 1409 | arm_kprobe(p); |
de5bd88d MH |
1410 | |
1411 | p->flags &= ~KPROBE_FLAG_DISABLED; | |
1412 | if (p != kp) | |
1413 | kp->flags &= ~KPROBE_FLAG_DISABLED; | |
1414 | out: | |
1415 | mutex_unlock(&kprobe_mutex); | |
1416 | return ret; | |
1417 | } | |
1418 | EXPORT_SYMBOL_GPL(enable_kprobe); | |
1419 | ||
e579abeb | 1420 | static void __kprobes arm_all_kprobes(void) |
bf8f6e5b AM |
1421 | { |
1422 | struct hlist_head *head; | |
1423 | struct hlist_node *node; | |
1424 | struct kprobe *p; | |
1425 | unsigned int i; | |
1426 | ||
1427 | mutex_lock(&kprobe_mutex); | |
1428 | ||
e579abeb MH |
1429 | /* If kprobes are armed, just return */ |
1430 | if (!kprobes_all_disarmed) | |
bf8f6e5b AM |
1431 | goto already_enabled; |
1432 | ||
4460fdad | 1433 | mutex_lock(&text_mutex); |
bf8f6e5b AM |
1434 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
1435 | head = &kprobe_table[i]; | |
1436 | hlist_for_each_entry_rcu(p, node, head, hlist) | |
de5bd88d | 1437 | if (!kprobe_disabled(p)) |
e8386a0c | 1438 | arch_arm_kprobe(p); |
bf8f6e5b | 1439 | } |
4460fdad | 1440 | mutex_unlock(&text_mutex); |
bf8f6e5b | 1441 | |
e579abeb | 1442 | kprobes_all_disarmed = false; |
bf8f6e5b AM |
1443 | printk(KERN_INFO "Kprobes globally enabled\n"); |
1444 | ||
1445 | already_enabled: | |
1446 | mutex_unlock(&kprobe_mutex); | |
1447 | return; | |
1448 | } | |
1449 | ||
e579abeb | 1450 | static void __kprobes disarm_all_kprobes(void) |
bf8f6e5b AM |
1451 | { |
1452 | struct hlist_head *head; | |
1453 | struct hlist_node *node; | |
1454 | struct kprobe *p; | |
1455 | unsigned int i; | |
1456 | ||
1457 | mutex_lock(&kprobe_mutex); | |
1458 | ||
e579abeb MH |
1459 | /* If kprobes are already disarmed, just return */ |
1460 | if (kprobes_all_disarmed) | |
bf8f6e5b AM |
1461 | goto already_disabled; |
1462 | ||
e579abeb | 1463 | kprobes_all_disarmed = true; |
bf8f6e5b | 1464 | printk(KERN_INFO "Kprobes globally disabled\n"); |
4460fdad | 1465 | mutex_lock(&text_mutex); |
bf8f6e5b AM |
1466 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
1467 | head = &kprobe_table[i]; | |
1468 | hlist_for_each_entry_rcu(p, node, head, hlist) { | |
de5bd88d | 1469 | if (!arch_trampoline_kprobe(p) && !kprobe_disabled(p)) |
bf8f6e5b AM |
1470 | arch_disarm_kprobe(p); |
1471 | } | |
1472 | } | |
1473 | ||
4460fdad | 1474 | mutex_unlock(&text_mutex); |
bf8f6e5b AM |
1475 | mutex_unlock(&kprobe_mutex); |
1476 | /* Allow all currently running kprobes to complete */ | |
1477 | synchronize_sched(); | |
74a0b576 | 1478 | return; |
bf8f6e5b AM |
1479 | |
1480 | already_disabled: | |
1481 | mutex_unlock(&kprobe_mutex); | |
1482 | return; | |
1483 | } | |
1484 | ||
1485 | /* | |
1486 | * XXX: The debugfs bool file interface doesn't allow for callbacks | |
1487 | * when the bool state is switched. We can reuse that facility when | |
1488 | * available | |
1489 | */ | |
1490 | static ssize_t read_enabled_file_bool(struct file *file, | |
1491 | char __user *user_buf, size_t count, loff_t *ppos) | |
1492 | { | |
1493 | char buf[3]; | |
1494 | ||
e579abeb | 1495 | if (!kprobes_all_disarmed) |
bf8f6e5b AM |
1496 | buf[0] = '1'; |
1497 | else | |
1498 | buf[0] = '0'; | |
1499 | buf[1] = '\n'; | |
1500 | buf[2] = 0x00; | |
1501 | return simple_read_from_buffer(user_buf, count, ppos, buf, 2); | |
1502 | } | |
1503 | ||
1504 | static ssize_t write_enabled_file_bool(struct file *file, | |
1505 | const char __user *user_buf, size_t count, loff_t *ppos) | |
1506 | { | |
1507 | char buf[32]; | |
1508 | int buf_size; | |
1509 | ||
1510 | buf_size = min(count, (sizeof(buf)-1)); | |
1511 | if (copy_from_user(buf, user_buf, buf_size)) | |
1512 | return -EFAULT; | |
1513 | ||
1514 | switch (buf[0]) { | |
1515 | case 'y': | |
1516 | case 'Y': | |
1517 | case '1': | |
e579abeb | 1518 | arm_all_kprobes(); |
bf8f6e5b AM |
1519 | break; |
1520 | case 'n': | |
1521 | case 'N': | |
1522 | case '0': | |
e579abeb | 1523 | disarm_all_kprobes(); |
bf8f6e5b AM |
1524 | break; |
1525 | } | |
1526 | ||
1527 | return count; | |
1528 | } | |
1529 | ||
1530 | static struct file_operations fops_kp = { | |
1531 | .read = read_enabled_file_bool, | |
1532 | .write = write_enabled_file_bool, | |
1533 | }; | |
1534 | ||
346fd59b SD |
1535 | static int __kprobes debugfs_kprobe_init(void) |
1536 | { | |
1537 | struct dentry *dir, *file; | |
bf8f6e5b | 1538 | unsigned int value = 1; |
346fd59b SD |
1539 | |
1540 | dir = debugfs_create_dir("kprobes", NULL); | |
1541 | if (!dir) | |
1542 | return -ENOMEM; | |
1543 | ||
e3869792 | 1544 | file = debugfs_create_file("list", 0444, dir, NULL, |
346fd59b SD |
1545 | &debugfs_kprobes_operations); |
1546 | if (!file) { | |
1547 | debugfs_remove(dir); | |
1548 | return -ENOMEM; | |
1549 | } | |
1550 | ||
bf8f6e5b AM |
1551 | file = debugfs_create_file("enabled", 0600, dir, |
1552 | &value, &fops_kp); | |
1553 | if (!file) { | |
1554 | debugfs_remove(dir); | |
1555 | return -ENOMEM; | |
1556 | } | |
1557 | ||
346fd59b SD |
1558 | return 0; |
1559 | } | |
1560 | ||
1561 | late_initcall(debugfs_kprobe_init); | |
1562 | #endif /* CONFIG_DEBUG_FS */ | |
1563 | ||
1564 | module_init(init_kprobes); | |
1da177e4 | 1565 | |
99081ab5 | 1566 | /* defined in arch/.../kernel/kprobes.c */ |
1da177e4 | 1567 | EXPORT_SYMBOL_GPL(jprobe_return); |