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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 | 92 | {"preempt_schedule",}, |
65e234ec | 93 | {"native_get_debugreg",}, |
a00e817f MH |
94 | {"irq_entries_start",}, |
95 | {"common_interrupt",}, | |
3d8d996e SD |
96 | {NULL} /* Terminator */ |
97 | }; | |
98 | ||
2d14e39d | 99 | #ifdef __ARCH_WANT_KPROBES_INSN_SLOT |
9ec4b1f3 AM |
100 | /* |
101 | * kprobe->ainsn.insn points to the copy of the instruction to be | |
102 | * single-stepped. x86_64, POWER4 and above have no-exec support and | |
103 | * stepping on the instruction on a vmalloced/kmalloced/data page | |
104 | * is a recipe for disaster | |
105 | */ | |
106 | #define INSNS_PER_PAGE (PAGE_SIZE/(MAX_INSN_SIZE * sizeof(kprobe_opcode_t))) | |
107 | ||
108 | struct kprobe_insn_page { | |
c5cb5a2d | 109 | struct list_head list; |
9ec4b1f3 AM |
110 | kprobe_opcode_t *insns; /* Page of instruction slots */ |
111 | char slot_used[INSNS_PER_PAGE]; | |
112 | int nused; | |
b4c6c34a | 113 | int ngarbage; |
9ec4b1f3 AM |
114 | }; |
115 | ||
ab40c5c6 MH |
116 | enum kprobe_slot_state { |
117 | SLOT_CLEAN = 0, | |
118 | SLOT_DIRTY = 1, | |
119 | SLOT_USED = 2, | |
120 | }; | |
121 | ||
12941560 | 122 | static DEFINE_MUTEX(kprobe_insn_mutex); /* Protects kprobe_insn_pages */ |
c5cb5a2d | 123 | static LIST_HEAD(kprobe_insn_pages); |
b4c6c34a MH |
124 | static int kprobe_garbage_slots; |
125 | static int collect_garbage_slots(void); | |
126 | ||
9ec4b1f3 | 127 | /** |
12941560 | 128 | * __get_insn_slot() - Find a slot on an executable page for an instruction. |
9ec4b1f3 AM |
129 | * We allocate an executable page if there's no room on existing ones. |
130 | */ | |
12941560 | 131 | static kprobe_opcode_t __kprobes *__get_insn_slot(void) |
9ec4b1f3 AM |
132 | { |
133 | struct kprobe_insn_page *kip; | |
9ec4b1f3 | 134 | |
6f716acd | 135 | retry: |
c5cb5a2d | 136 | list_for_each_entry(kip, &kprobe_insn_pages, list) { |
9ec4b1f3 AM |
137 | if (kip->nused < INSNS_PER_PAGE) { |
138 | int i; | |
139 | for (i = 0; i < INSNS_PER_PAGE; i++) { | |
ab40c5c6 MH |
140 | if (kip->slot_used[i] == SLOT_CLEAN) { |
141 | kip->slot_used[i] = SLOT_USED; | |
9ec4b1f3 AM |
142 | kip->nused++; |
143 | return kip->insns + (i * MAX_INSN_SIZE); | |
144 | } | |
145 | } | |
146 | /* Surprise! No unused slots. Fix kip->nused. */ | |
147 | kip->nused = INSNS_PER_PAGE; | |
148 | } | |
149 | } | |
150 | ||
b4c6c34a MH |
151 | /* If there are any garbage slots, collect it and try again. */ |
152 | if (kprobe_garbage_slots && collect_garbage_slots() == 0) { | |
153 | goto retry; | |
154 | } | |
155 | /* All out of space. Need to allocate a new page. Use slot 0. */ | |
9ec4b1f3 | 156 | kip = kmalloc(sizeof(struct kprobe_insn_page), GFP_KERNEL); |
6f716acd | 157 | if (!kip) |
9ec4b1f3 | 158 | return NULL; |
9ec4b1f3 AM |
159 | |
160 | /* | |
161 | * Use module_alloc so this page is within +/- 2GB of where the | |
162 | * kernel image and loaded module images reside. This is required | |
163 | * so x86_64 can correctly handle the %rip-relative fixups. | |
164 | */ | |
165 | kip->insns = module_alloc(PAGE_SIZE); | |
166 | if (!kip->insns) { | |
167 | kfree(kip); | |
168 | return NULL; | |
169 | } | |
c5cb5a2d MH |
170 | INIT_LIST_HEAD(&kip->list); |
171 | list_add(&kip->list, &kprobe_insn_pages); | |
ab40c5c6 MH |
172 | memset(kip->slot_used, SLOT_CLEAN, INSNS_PER_PAGE); |
173 | kip->slot_used[0] = SLOT_USED; | |
9ec4b1f3 | 174 | kip->nused = 1; |
b4c6c34a | 175 | kip->ngarbage = 0; |
9ec4b1f3 AM |
176 | return kip->insns; |
177 | } | |
178 | ||
12941560 MH |
179 | kprobe_opcode_t __kprobes *get_insn_slot(void) |
180 | { | |
181 | kprobe_opcode_t *ret; | |
182 | mutex_lock(&kprobe_insn_mutex); | |
183 | ret = __get_insn_slot(); | |
184 | mutex_unlock(&kprobe_insn_mutex); | |
185 | return ret; | |
186 | } | |
187 | ||
b4c6c34a MH |
188 | /* Return 1 if all garbages are collected, otherwise 0. */ |
189 | static int __kprobes collect_one_slot(struct kprobe_insn_page *kip, int idx) | |
190 | { | |
ab40c5c6 | 191 | kip->slot_used[idx] = SLOT_CLEAN; |
b4c6c34a MH |
192 | kip->nused--; |
193 | if (kip->nused == 0) { | |
194 | /* | |
195 | * Page is no longer in use. Free it unless | |
196 | * it's the last one. We keep the last one | |
197 | * so as not to have to set it up again the | |
198 | * next time somebody inserts a probe. | |
199 | */ | |
c5cb5a2d MH |
200 | if (!list_is_singular(&kprobe_insn_pages)) { |
201 | list_del(&kip->list); | |
b4c6c34a MH |
202 | module_free(NULL, kip->insns); |
203 | kfree(kip); | |
204 | } | |
205 | return 1; | |
206 | } | |
207 | return 0; | |
208 | } | |
209 | ||
210 | static int __kprobes collect_garbage_slots(void) | |
211 | { | |
c5cb5a2d | 212 | struct kprobe_insn_page *kip, *next; |
b4c6c34a | 213 | |
615d0ebb MH |
214 | /* Ensure no-one is interrupted on the garbages */ |
215 | synchronize_sched(); | |
b4c6c34a | 216 | |
c5cb5a2d | 217 | list_for_each_entry_safe(kip, next, &kprobe_insn_pages, list) { |
b4c6c34a | 218 | int i; |
b4c6c34a MH |
219 | if (kip->ngarbage == 0) |
220 | continue; | |
221 | kip->ngarbage = 0; /* we will collect all garbages */ | |
222 | for (i = 0; i < INSNS_PER_PAGE; i++) { | |
ab40c5c6 | 223 | if (kip->slot_used[i] == SLOT_DIRTY && |
b4c6c34a MH |
224 | collect_one_slot(kip, i)) |
225 | break; | |
226 | } | |
227 | } | |
228 | kprobe_garbage_slots = 0; | |
229 | return 0; | |
230 | } | |
231 | ||
232 | void __kprobes free_insn_slot(kprobe_opcode_t * slot, int dirty) | |
9ec4b1f3 AM |
233 | { |
234 | struct kprobe_insn_page *kip; | |
9ec4b1f3 | 235 | |
12941560 | 236 | mutex_lock(&kprobe_insn_mutex); |
c5cb5a2d | 237 | list_for_each_entry(kip, &kprobe_insn_pages, list) { |
9ec4b1f3 AM |
238 | if (kip->insns <= slot && |
239 | slot < kip->insns + (INSNS_PER_PAGE * MAX_INSN_SIZE)) { | |
240 | int i = (slot - kip->insns) / MAX_INSN_SIZE; | |
b4c6c34a | 241 | if (dirty) { |
ab40c5c6 | 242 | kip->slot_used[i] = SLOT_DIRTY; |
b4c6c34a | 243 | kip->ngarbage++; |
c5cb5a2d | 244 | } else |
b4c6c34a | 245 | collect_one_slot(kip, i); |
b4c6c34a | 246 | break; |
9ec4b1f3 AM |
247 | } |
248 | } | |
6f716acd CH |
249 | |
250 | if (dirty && ++kprobe_garbage_slots > INSNS_PER_PAGE) | |
b4c6c34a | 251 | collect_garbage_slots(); |
12941560 MH |
252 | |
253 | mutex_unlock(&kprobe_insn_mutex); | |
9ec4b1f3 | 254 | } |
2d14e39d | 255 | #endif |
9ec4b1f3 | 256 | |
e6584523 AM |
257 | /* We have preemption disabled.. so it is safe to use __ versions */ |
258 | static inline void set_kprobe_instance(struct kprobe *kp) | |
259 | { | |
260 | __get_cpu_var(kprobe_instance) = kp; | |
261 | } | |
262 | ||
263 | static inline void reset_kprobe_instance(void) | |
264 | { | |
265 | __get_cpu_var(kprobe_instance) = NULL; | |
266 | } | |
267 | ||
3516a460 AM |
268 | /* |
269 | * This routine is called either: | |
49a2a1b8 | 270 | * - under the kprobe_mutex - during kprobe_[un]register() |
3516a460 | 271 | * OR |
d217d545 | 272 | * - with preemption disabled - from arch/xxx/kernel/kprobes.c |
3516a460 | 273 | */ |
d0aaff97 | 274 | struct kprobe __kprobes *get_kprobe(void *addr) |
1da177e4 LT |
275 | { |
276 | struct hlist_head *head; | |
277 | struct hlist_node *node; | |
3516a460 | 278 | struct kprobe *p; |
1da177e4 LT |
279 | |
280 | head = &kprobe_table[hash_ptr(addr, KPROBE_HASH_BITS)]; | |
3516a460 | 281 | hlist_for_each_entry_rcu(p, node, head, hlist) { |
1da177e4 LT |
282 | if (p->addr == addr) |
283 | return p; | |
284 | } | |
285 | return NULL; | |
286 | } | |
287 | ||
201517a7 MH |
288 | /* Arm a kprobe with text_mutex */ |
289 | static void __kprobes arm_kprobe(struct kprobe *kp) | |
290 | { | |
291 | mutex_lock(&text_mutex); | |
292 | arch_arm_kprobe(kp); | |
293 | mutex_unlock(&text_mutex); | |
294 | } | |
295 | ||
296 | /* Disarm a kprobe with text_mutex */ | |
297 | static void __kprobes disarm_kprobe(struct kprobe *kp) | |
298 | { | |
299 | mutex_lock(&text_mutex); | |
300 | arch_disarm_kprobe(kp); | |
301 | mutex_unlock(&text_mutex); | |
302 | } | |
303 | ||
64f562c6 AM |
304 | /* |
305 | * Aggregate handlers for multiple kprobes support - these handlers | |
306 | * take care of invoking the individual kprobe handlers on p->list | |
307 | */ | |
d0aaff97 | 308 | static int __kprobes aggr_pre_handler(struct kprobe *p, struct pt_regs *regs) |
64f562c6 AM |
309 | { |
310 | struct kprobe *kp; | |
311 | ||
3516a460 | 312 | list_for_each_entry_rcu(kp, &p->list, list) { |
de5bd88d | 313 | if (kp->pre_handler && likely(!kprobe_disabled(kp))) { |
e6584523 | 314 | set_kprobe_instance(kp); |
8b0914ea PP |
315 | if (kp->pre_handler(kp, regs)) |
316 | return 1; | |
64f562c6 | 317 | } |
e6584523 | 318 | reset_kprobe_instance(); |
64f562c6 AM |
319 | } |
320 | return 0; | |
321 | } | |
322 | ||
d0aaff97 PP |
323 | static void __kprobes aggr_post_handler(struct kprobe *p, struct pt_regs *regs, |
324 | unsigned long flags) | |
64f562c6 AM |
325 | { |
326 | struct kprobe *kp; | |
327 | ||
3516a460 | 328 | list_for_each_entry_rcu(kp, &p->list, list) { |
de5bd88d | 329 | if (kp->post_handler && likely(!kprobe_disabled(kp))) { |
e6584523 | 330 | set_kprobe_instance(kp); |
64f562c6 | 331 | kp->post_handler(kp, regs, flags); |
e6584523 | 332 | reset_kprobe_instance(); |
64f562c6 AM |
333 | } |
334 | } | |
64f562c6 AM |
335 | } |
336 | ||
d0aaff97 PP |
337 | static int __kprobes aggr_fault_handler(struct kprobe *p, struct pt_regs *regs, |
338 | int trapnr) | |
64f562c6 | 339 | { |
e6584523 AM |
340 | struct kprobe *cur = __get_cpu_var(kprobe_instance); |
341 | ||
64f562c6 AM |
342 | /* |
343 | * if we faulted "during" the execution of a user specified | |
344 | * probe handler, invoke just that probe's fault handler | |
345 | */ | |
e6584523 AM |
346 | if (cur && cur->fault_handler) { |
347 | if (cur->fault_handler(cur, regs, trapnr)) | |
64f562c6 AM |
348 | return 1; |
349 | } | |
350 | return 0; | |
351 | } | |
352 | ||
d0aaff97 | 353 | static int __kprobes aggr_break_handler(struct kprobe *p, struct pt_regs *regs) |
8b0914ea | 354 | { |
e6584523 AM |
355 | struct kprobe *cur = __get_cpu_var(kprobe_instance); |
356 | int ret = 0; | |
357 | ||
358 | if (cur && cur->break_handler) { | |
359 | if (cur->break_handler(cur, regs)) | |
360 | ret = 1; | |
8b0914ea | 361 | } |
e6584523 AM |
362 | reset_kprobe_instance(); |
363 | return ret; | |
8b0914ea PP |
364 | } |
365 | ||
bf8d5c52 KA |
366 | /* Walks the list and increments nmissed count for multiprobe case */ |
367 | void __kprobes kprobes_inc_nmissed_count(struct kprobe *p) | |
368 | { | |
369 | struct kprobe *kp; | |
370 | if (p->pre_handler != aggr_pre_handler) { | |
371 | p->nmissed++; | |
372 | } else { | |
373 | list_for_each_entry_rcu(kp, &p->list, list) | |
374 | kp->nmissed++; | |
375 | } | |
376 | return; | |
377 | } | |
378 | ||
99219a3f | 379 | void __kprobes recycle_rp_inst(struct kretprobe_instance *ri, |
380 | struct hlist_head *head) | |
b94cce92 | 381 | { |
ef53d9c5 S |
382 | struct kretprobe *rp = ri->rp; |
383 | ||
b94cce92 HN |
384 | /* remove rp inst off the rprobe_inst_table */ |
385 | hlist_del(&ri->hlist); | |
ef53d9c5 S |
386 | INIT_HLIST_NODE(&ri->hlist); |
387 | if (likely(rp)) { | |
388 | spin_lock(&rp->lock); | |
389 | hlist_add_head(&ri->hlist, &rp->free_instances); | |
390 | spin_unlock(&rp->lock); | |
b94cce92 HN |
391 | } else |
392 | /* Unregistering */ | |
99219a3f | 393 | hlist_add_head(&ri->hlist, head); |
b94cce92 HN |
394 | } |
395 | ||
017c39bd | 396 | void __kprobes kretprobe_hash_lock(struct task_struct *tsk, |
ef53d9c5 S |
397 | struct hlist_head **head, unsigned long *flags) |
398 | { | |
399 | unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS); | |
400 | spinlock_t *hlist_lock; | |
401 | ||
402 | *head = &kretprobe_inst_table[hash]; | |
403 | hlist_lock = kretprobe_table_lock_ptr(hash); | |
404 | spin_lock_irqsave(hlist_lock, *flags); | |
405 | } | |
406 | ||
017c39bd MH |
407 | static void __kprobes kretprobe_table_lock(unsigned long hash, |
408 | unsigned long *flags) | |
b94cce92 | 409 | { |
ef53d9c5 S |
410 | spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash); |
411 | spin_lock_irqsave(hlist_lock, *flags); | |
412 | } | |
413 | ||
017c39bd MH |
414 | void __kprobes kretprobe_hash_unlock(struct task_struct *tsk, |
415 | unsigned long *flags) | |
ef53d9c5 S |
416 | { |
417 | unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS); | |
418 | spinlock_t *hlist_lock; | |
419 | ||
420 | hlist_lock = kretprobe_table_lock_ptr(hash); | |
421 | spin_unlock_irqrestore(hlist_lock, *flags); | |
422 | } | |
423 | ||
017c39bd | 424 | void __kprobes kretprobe_table_unlock(unsigned long hash, unsigned long *flags) |
ef53d9c5 S |
425 | { |
426 | spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash); | |
427 | spin_unlock_irqrestore(hlist_lock, *flags); | |
b94cce92 HN |
428 | } |
429 | ||
b94cce92 | 430 | /* |
c6fd91f0 | 431 | * This function is called from finish_task_switch when task tk becomes dead, |
432 | * so that we can recycle any function-return probe instances associated | |
433 | * with this task. These left over instances represent probed functions | |
434 | * that have been called but will never return. | |
b94cce92 | 435 | */ |
d0aaff97 | 436 | void __kprobes kprobe_flush_task(struct task_struct *tk) |
b94cce92 | 437 | { |
62c27be0 | 438 | struct kretprobe_instance *ri; |
99219a3f | 439 | struct hlist_head *head, empty_rp; |
802eae7c | 440 | struct hlist_node *node, *tmp; |
ef53d9c5 | 441 | unsigned long hash, flags = 0; |
802eae7c | 442 | |
ef53d9c5 S |
443 | if (unlikely(!kprobes_initialized)) |
444 | /* Early boot. kretprobe_table_locks not yet initialized. */ | |
445 | return; | |
446 | ||
447 | hash = hash_ptr(tk, KPROBE_HASH_BITS); | |
448 | head = &kretprobe_inst_table[hash]; | |
449 | kretprobe_table_lock(hash, &flags); | |
62c27be0 | 450 | hlist_for_each_entry_safe(ri, node, tmp, head, hlist) { |
451 | if (ri->task == tk) | |
99219a3f | 452 | recycle_rp_inst(ri, &empty_rp); |
62c27be0 | 453 | } |
ef53d9c5 S |
454 | kretprobe_table_unlock(hash, &flags); |
455 | INIT_HLIST_HEAD(&empty_rp); | |
99219a3f | 456 | hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) { |
457 | hlist_del(&ri->hlist); | |
458 | kfree(ri); | |
459 | } | |
b94cce92 HN |
460 | } |
461 | ||
b94cce92 HN |
462 | static inline void free_rp_inst(struct kretprobe *rp) |
463 | { | |
464 | struct kretprobe_instance *ri; | |
4c4308cb CH |
465 | struct hlist_node *pos, *next; |
466 | ||
ef53d9c5 S |
467 | hlist_for_each_entry_safe(ri, pos, next, &rp->free_instances, hlist) { |
468 | hlist_del(&ri->hlist); | |
b94cce92 HN |
469 | kfree(ri); |
470 | } | |
471 | } | |
472 | ||
4a296e07 MH |
473 | static void __kprobes cleanup_rp_inst(struct kretprobe *rp) |
474 | { | |
ef53d9c5 | 475 | unsigned long flags, hash; |
4a296e07 MH |
476 | struct kretprobe_instance *ri; |
477 | struct hlist_node *pos, *next; | |
ef53d9c5 S |
478 | struct hlist_head *head; |
479 | ||
4a296e07 | 480 | /* No race here */ |
ef53d9c5 S |
481 | for (hash = 0; hash < KPROBE_TABLE_SIZE; hash++) { |
482 | kretprobe_table_lock(hash, &flags); | |
483 | head = &kretprobe_inst_table[hash]; | |
484 | hlist_for_each_entry_safe(ri, pos, next, head, hlist) { | |
485 | if (ri->rp == rp) | |
486 | ri->rp = NULL; | |
487 | } | |
488 | kretprobe_table_unlock(hash, &flags); | |
4a296e07 | 489 | } |
4a296e07 MH |
490 | free_rp_inst(rp); |
491 | } | |
492 | ||
8b0914ea PP |
493 | /* |
494 | * Keep all fields in the kprobe consistent | |
495 | */ | |
496 | static inline void copy_kprobe(struct kprobe *old_p, struct kprobe *p) | |
497 | { | |
498 | memcpy(&p->opcode, &old_p->opcode, sizeof(kprobe_opcode_t)); | |
499 | memcpy(&p->ainsn, &old_p->ainsn, sizeof(struct arch_specific_insn)); | |
500 | } | |
501 | ||
502 | /* | |
b918e5e6 | 503 | * Add the new probe to ap->list. Fail if this is the |
8b0914ea PP |
504 | * second jprobe at the address - two jprobes can't coexist |
505 | */ | |
b918e5e6 | 506 | static int __kprobes add_new_kprobe(struct kprobe *ap, struct kprobe *p) |
8b0914ea | 507 | { |
de5bd88d | 508 | BUG_ON(kprobe_gone(ap) || kprobe_gone(p)); |
8b0914ea | 509 | if (p->break_handler) { |
b918e5e6 | 510 | if (ap->break_handler) |
36721656 | 511 | return -EEXIST; |
b918e5e6 MH |
512 | list_add_tail_rcu(&p->list, &ap->list); |
513 | ap->break_handler = aggr_break_handler; | |
8b0914ea | 514 | } else |
b918e5e6 MH |
515 | list_add_rcu(&p->list, &ap->list); |
516 | if (p->post_handler && !ap->post_handler) | |
517 | ap->post_handler = aggr_post_handler; | |
de5bd88d MH |
518 | |
519 | if (kprobe_disabled(ap) && !kprobe_disabled(p)) { | |
520 | ap->flags &= ~KPROBE_FLAG_DISABLED; | |
521 | if (!kprobes_all_disarmed) | |
522 | /* Arm the breakpoint again. */ | |
201517a7 | 523 | arm_kprobe(ap); |
de5bd88d | 524 | } |
8b0914ea PP |
525 | return 0; |
526 | } | |
527 | ||
64f562c6 AM |
528 | /* |
529 | * Fill in the required fields of the "manager kprobe". Replace the | |
530 | * earlier kprobe in the hlist with the manager kprobe | |
531 | */ | |
532 | static inline void add_aggr_kprobe(struct kprobe *ap, struct kprobe *p) | |
533 | { | |
8b0914ea | 534 | copy_kprobe(p, ap); |
a9ad965e | 535 | flush_insn_slot(ap); |
64f562c6 | 536 | ap->addr = p->addr; |
b918e5e6 | 537 | ap->flags = p->flags; |
64f562c6 | 538 | ap->pre_handler = aggr_pre_handler; |
64f562c6 | 539 | ap->fault_handler = aggr_fault_handler; |
e8386a0c MH |
540 | /* We don't care the kprobe which has gone. */ |
541 | if (p->post_handler && !kprobe_gone(p)) | |
36721656 | 542 | ap->post_handler = aggr_post_handler; |
e8386a0c | 543 | if (p->break_handler && !kprobe_gone(p)) |
36721656 | 544 | ap->break_handler = aggr_break_handler; |
64f562c6 AM |
545 | |
546 | INIT_LIST_HEAD(&ap->list); | |
3516a460 | 547 | list_add_rcu(&p->list, &ap->list); |
64f562c6 | 548 | |
adad0f33 | 549 | hlist_replace_rcu(&p->hlist, &ap->hlist); |
64f562c6 AM |
550 | } |
551 | ||
552 | /* | |
553 | * This is the second or subsequent kprobe at the address - handle | |
554 | * the intricacies | |
64f562c6 | 555 | */ |
d0aaff97 PP |
556 | static int __kprobes register_aggr_kprobe(struct kprobe *old_p, |
557 | struct kprobe *p) | |
64f562c6 AM |
558 | { |
559 | int ret = 0; | |
b918e5e6 | 560 | struct kprobe *ap = old_p; |
64f562c6 | 561 | |
b918e5e6 MH |
562 | if (old_p->pre_handler != aggr_pre_handler) { |
563 | /* If old_p is not an aggr_probe, create new aggr_kprobe. */ | |
564 | ap = kzalloc(sizeof(struct kprobe), GFP_KERNEL); | |
565 | if (!ap) | |
566 | return -ENOMEM; | |
567 | add_aggr_kprobe(ap, old_p); | |
568 | } | |
569 | ||
570 | if (kprobe_gone(ap)) { | |
e8386a0c MH |
571 | /* |
572 | * Attempting to insert new probe at the same location that | |
573 | * had a probe in the module vaddr area which already | |
574 | * freed. So, the instruction slot has already been | |
575 | * released. We need a new slot for the new probe. | |
576 | */ | |
b918e5e6 | 577 | ret = arch_prepare_kprobe(ap); |
e8386a0c | 578 | if (ret) |
b918e5e6 MH |
579 | /* |
580 | * Even if fail to allocate new slot, don't need to | |
581 | * free aggr_probe. It will be used next time, or | |
582 | * freed by unregister_kprobe. | |
583 | */ | |
e8386a0c | 584 | return ret; |
de5bd88d | 585 | |
e8386a0c | 586 | /* |
de5bd88d MH |
587 | * Clear gone flag to prevent allocating new slot again, and |
588 | * set disabled flag because it is not armed yet. | |
e8386a0c | 589 | */ |
de5bd88d MH |
590 | ap->flags = (ap->flags & ~KPROBE_FLAG_GONE) |
591 | | KPROBE_FLAG_DISABLED; | |
e8386a0c | 592 | } |
b918e5e6 MH |
593 | |
594 | copy_kprobe(ap, p); | |
595 | return add_new_kprobe(ap, p); | |
64f562c6 AM |
596 | } |
597 | ||
de5bd88d MH |
598 | /* Try to disable aggr_kprobe, and return 1 if succeeded.*/ |
599 | static int __kprobes try_to_disable_aggr_kprobe(struct kprobe *p) | |
600 | { | |
601 | struct kprobe *kp; | |
602 | ||
603 | list_for_each_entry_rcu(kp, &p->list, list) { | |
604 | if (!kprobe_disabled(kp)) | |
605 | /* | |
606 | * There is an active probe on the list. | |
607 | * We can't disable aggr_kprobe. | |
608 | */ | |
609 | return 0; | |
610 | } | |
611 | p->flags |= KPROBE_FLAG_DISABLED; | |
612 | return 1; | |
613 | } | |
614 | ||
d0aaff97 PP |
615 | static int __kprobes in_kprobes_functions(unsigned long addr) |
616 | { | |
3d8d996e SD |
617 | struct kprobe_blackpoint *kb; |
618 | ||
6f716acd CH |
619 | if (addr >= (unsigned long)__kprobes_text_start && |
620 | addr < (unsigned long)__kprobes_text_end) | |
d0aaff97 | 621 | return -EINVAL; |
3d8d996e SD |
622 | /* |
623 | * If there exists a kprobe_blacklist, verify and | |
624 | * fail any probe registration in the prohibited area | |
625 | */ | |
626 | for (kb = kprobe_blacklist; kb->name != NULL; kb++) { | |
627 | if (kb->start_addr) { | |
628 | if (addr >= kb->start_addr && | |
629 | addr < (kb->start_addr + kb->range)) | |
630 | return -EINVAL; | |
631 | } | |
632 | } | |
d0aaff97 PP |
633 | return 0; |
634 | } | |
635 | ||
b2a5cd69 MH |
636 | /* |
637 | * If we have a symbol_name argument, look it up and add the offset field | |
638 | * to it. This way, we can specify a relative address to a symbol. | |
639 | */ | |
640 | static kprobe_opcode_t __kprobes *kprobe_addr(struct kprobe *p) | |
641 | { | |
642 | kprobe_opcode_t *addr = p->addr; | |
643 | if (p->symbol_name) { | |
644 | if (addr) | |
645 | return NULL; | |
646 | kprobe_lookup_name(p->symbol_name, addr); | |
647 | } | |
648 | ||
649 | if (!addr) | |
650 | return NULL; | |
651 | return (kprobe_opcode_t *)(((char *)addr) + p->offset); | |
652 | } | |
653 | ||
1f0ab409 AM |
654 | /* Check passed kprobe is valid and return kprobe in kprobe_table. */ |
655 | static struct kprobe * __kprobes __get_valid_kprobe(struct kprobe *p) | |
656 | { | |
657 | struct kprobe *old_p, *list_p; | |
658 | ||
659 | old_p = get_kprobe(p->addr); | |
660 | if (unlikely(!old_p)) | |
661 | return NULL; | |
662 | ||
663 | if (p != old_p) { | |
664 | list_for_each_entry_rcu(list_p, &old_p->list, list) | |
665 | if (list_p == p) | |
666 | /* kprobe p is a valid probe */ | |
667 | goto valid; | |
668 | return NULL; | |
669 | } | |
670 | valid: | |
671 | return old_p; | |
672 | } | |
673 | ||
674 | /* Return error if the kprobe is being re-registered */ | |
675 | static inline int check_kprobe_rereg(struct kprobe *p) | |
676 | { | |
677 | int ret = 0; | |
678 | struct kprobe *old_p; | |
679 | ||
680 | mutex_lock(&kprobe_mutex); | |
681 | old_p = __get_valid_kprobe(p); | |
682 | if (old_p) | |
683 | ret = -EINVAL; | |
684 | mutex_unlock(&kprobe_mutex); | |
685 | return ret; | |
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 | |
1f0ab409 AM |
700 | ret = check_kprobe_rereg(p); |
701 | if (ret) | |
702 | return ret; | |
703 | ||
a189d035 | 704 | preempt_disable(); |
ec30c5f3 | 705 | if (!kernel_text_address((unsigned long) p->addr) || |
a189d035 MH |
706 | in_kprobes_functions((unsigned long) p->addr)) { |
707 | preempt_enable(); | |
b3e55c72 | 708 | return -EINVAL; |
a189d035 | 709 | } |
b3e55c72 | 710 | |
de5bd88d MH |
711 | /* User can pass only KPROBE_FLAG_DISABLED to register_kprobe */ |
712 | p->flags &= KPROBE_FLAG_DISABLED; | |
713 | ||
6f716acd CH |
714 | /* |
715 | * Check if are we probing a module. | |
716 | */ | |
a189d035 | 717 | probed_mod = __module_text_address((unsigned long) p->addr); |
6f716acd | 718 | if (probed_mod) { |
6f716acd | 719 | /* |
e8386a0c MH |
720 | * We must hold a refcount of the probed module while updating |
721 | * its code to prohibit unexpected unloading. | |
df019b1d | 722 | */ |
49ad2fd7 MH |
723 | if (unlikely(!try_module_get(probed_mod))) { |
724 | preempt_enable(); | |
725 | return -EINVAL; | |
726 | } | |
f24659d9 MH |
727 | /* |
728 | * If the module freed .init.text, we couldn't insert | |
729 | * kprobes in there. | |
730 | */ | |
731 | if (within_module_init((unsigned long)p->addr, probed_mod) && | |
732 | probed_mod->state != MODULE_STATE_COMING) { | |
733 | module_put(probed_mod); | |
734 | preempt_enable(); | |
735 | return -EINVAL; | |
736 | } | |
df019b1d | 737 | } |
a189d035 | 738 | preempt_enable(); |
1da177e4 | 739 | |
3516a460 | 740 | p->nmissed = 0; |
9861668f | 741 | INIT_LIST_HEAD(&p->list); |
7a7d1cf9 | 742 | mutex_lock(&kprobe_mutex); |
64f562c6 AM |
743 | old_p = get_kprobe(p->addr); |
744 | if (old_p) { | |
745 | ret = register_aggr_kprobe(old_p, p); | |
1da177e4 LT |
746 | goto out; |
747 | } | |
1da177e4 | 748 | |
4460fdad | 749 | mutex_lock(&text_mutex); |
6f716acd CH |
750 | ret = arch_prepare_kprobe(p); |
751 | if (ret) | |
4460fdad | 752 | goto out_unlock_text; |
49a2a1b8 | 753 | |
64f562c6 | 754 | INIT_HLIST_NODE(&p->hlist); |
3516a460 | 755 | hlist_add_head_rcu(&p->hlist, |
1da177e4 LT |
756 | &kprobe_table[hash_ptr(p->addr, KPROBE_HASH_BITS)]); |
757 | ||
de5bd88d | 758 | if (!kprobes_all_disarmed && !kprobe_disabled(p)) |
bf8f6e5b | 759 | arch_arm_kprobe(p); |
74a0b576 | 760 | |
4460fdad MD |
761 | out_unlock_text: |
762 | mutex_unlock(&text_mutex); | |
1da177e4 | 763 | out: |
7a7d1cf9 | 764 | mutex_unlock(&kprobe_mutex); |
49a2a1b8 | 765 | |
e8386a0c | 766 | if (probed_mod) |
df019b1d | 767 | module_put(probed_mod); |
e8386a0c | 768 | |
1da177e4 LT |
769 | return ret; |
770 | } | |
99081ab5 | 771 | EXPORT_SYMBOL_GPL(register_kprobe); |
1da177e4 | 772 | |
de5bd88d MH |
773 | /* |
774 | * Unregister a kprobe without a scheduler synchronization. | |
775 | */ | |
776 | static int __kprobes __unregister_kprobe_top(struct kprobe *p) | |
777 | { | |
778 | struct kprobe *old_p, *list_p; | |
779 | ||
780 | old_p = __get_valid_kprobe(p); | |
781 | if (old_p == NULL) | |
782 | return -EINVAL; | |
783 | ||
6f716acd CH |
784 | if (old_p == p || |
785 | (old_p->pre_handler == aggr_pre_handler && | |
9861668f | 786 | list_is_singular(&old_p->list))) { |
bf8f6e5b AM |
787 | /* |
788 | * Only probe on the hash list. Disarm only if kprobes are | |
e8386a0c MH |
789 | * enabled and not gone - otherwise, the breakpoint would |
790 | * already have been removed. We save on flushing icache. | |
bf8f6e5b | 791 | */ |
201517a7 MH |
792 | if (!kprobes_all_disarmed && !kprobe_disabled(old_p)) |
793 | disarm_kprobe(p); | |
49a2a1b8 | 794 | hlist_del_rcu(&old_p->hlist); |
49a2a1b8 | 795 | } else { |
e8386a0c | 796 | if (p->break_handler && !kprobe_gone(p)) |
9861668f | 797 | old_p->break_handler = NULL; |
e8386a0c | 798 | if (p->post_handler && !kprobe_gone(p)) { |
9861668f MH |
799 | list_for_each_entry_rcu(list_p, &old_p->list, list) { |
800 | if ((list_p != p) && (list_p->post_handler)) | |
801 | goto noclean; | |
802 | } | |
803 | old_p->post_handler = NULL; | |
804 | } | |
805 | noclean: | |
49a2a1b8 | 806 | list_del_rcu(&p->list); |
de5bd88d MH |
807 | if (!kprobe_disabled(old_p)) { |
808 | try_to_disable_aggr_kprobe(old_p); | |
809 | if (!kprobes_all_disarmed && kprobe_disabled(old_p)) | |
201517a7 | 810 | disarm_kprobe(old_p); |
de5bd88d | 811 | } |
49a2a1b8 | 812 | } |
9861668f MH |
813 | return 0; |
814 | } | |
3516a460 | 815 | |
9861668f MH |
816 | static void __kprobes __unregister_kprobe_bottom(struct kprobe *p) |
817 | { | |
9861668f | 818 | struct kprobe *old_p; |
b3e55c72 | 819 | |
e8386a0c | 820 | if (list_empty(&p->list)) |
0498b635 | 821 | arch_remove_kprobe(p); |
e8386a0c MH |
822 | else if (list_is_singular(&p->list)) { |
823 | /* "p" is the last child of an aggr_kprobe */ | |
824 | old_p = list_entry(p->list.next, struct kprobe, list); | |
825 | list_del(&p->list); | |
826 | arch_remove_kprobe(old_p); | |
827 | kfree(old_p); | |
9861668f MH |
828 | } |
829 | } | |
830 | ||
49ad2fd7 | 831 | int __kprobes register_kprobes(struct kprobe **kps, int num) |
9861668f MH |
832 | { |
833 | int i, ret = 0; | |
834 | ||
835 | if (num <= 0) | |
836 | return -EINVAL; | |
837 | for (i = 0; i < num; i++) { | |
49ad2fd7 | 838 | ret = register_kprobe(kps[i]); |
67dddaad MH |
839 | if (ret < 0) { |
840 | if (i > 0) | |
841 | unregister_kprobes(kps, i); | |
9861668f | 842 | break; |
36721656 | 843 | } |
49a2a1b8 | 844 | } |
9861668f MH |
845 | return ret; |
846 | } | |
99081ab5 | 847 | EXPORT_SYMBOL_GPL(register_kprobes); |
9861668f | 848 | |
9861668f MH |
849 | void __kprobes unregister_kprobe(struct kprobe *p) |
850 | { | |
851 | unregister_kprobes(&p, 1); | |
852 | } | |
99081ab5 | 853 | EXPORT_SYMBOL_GPL(unregister_kprobe); |
9861668f | 854 | |
9861668f MH |
855 | void __kprobes unregister_kprobes(struct kprobe **kps, int num) |
856 | { | |
857 | int i; | |
858 | ||
859 | if (num <= 0) | |
860 | return; | |
861 | mutex_lock(&kprobe_mutex); | |
862 | for (i = 0; i < num; i++) | |
863 | if (__unregister_kprobe_top(kps[i]) < 0) | |
864 | kps[i]->addr = NULL; | |
865 | mutex_unlock(&kprobe_mutex); | |
866 | ||
867 | synchronize_sched(); | |
868 | for (i = 0; i < num; i++) | |
869 | if (kps[i]->addr) | |
870 | __unregister_kprobe_bottom(kps[i]); | |
1da177e4 | 871 | } |
99081ab5 | 872 | EXPORT_SYMBOL_GPL(unregister_kprobes); |
1da177e4 LT |
873 | |
874 | static struct notifier_block kprobe_exceptions_nb = { | |
3d5631e0 AK |
875 | .notifier_call = kprobe_exceptions_notify, |
876 | .priority = 0x7fffffff /* we need to be notified first */ | |
877 | }; | |
878 | ||
3d7e3382 ME |
879 | unsigned long __weak arch_deref_entry_point(void *entry) |
880 | { | |
881 | return (unsigned long)entry; | |
882 | } | |
1da177e4 | 883 | |
49ad2fd7 | 884 | int __kprobes register_jprobes(struct jprobe **jps, int num) |
1da177e4 | 885 | { |
26b31c19 MH |
886 | struct jprobe *jp; |
887 | int ret = 0, i; | |
3d7e3382 | 888 | |
26b31c19 | 889 | if (num <= 0) |
3d7e3382 | 890 | return -EINVAL; |
26b31c19 MH |
891 | for (i = 0; i < num; i++) { |
892 | unsigned long addr; | |
893 | jp = jps[i]; | |
894 | addr = arch_deref_entry_point(jp->entry); | |
895 | ||
896 | if (!kernel_text_address(addr)) | |
897 | ret = -EINVAL; | |
898 | else { | |
899 | /* Todo: Verify probepoint is a function entry point */ | |
900 | jp->kp.pre_handler = setjmp_pre_handler; | |
901 | jp->kp.break_handler = longjmp_break_handler; | |
49ad2fd7 | 902 | ret = register_kprobe(&jp->kp); |
26b31c19 | 903 | } |
67dddaad MH |
904 | if (ret < 0) { |
905 | if (i > 0) | |
906 | unregister_jprobes(jps, i); | |
26b31c19 MH |
907 | break; |
908 | } | |
909 | } | |
910 | return ret; | |
911 | } | |
99081ab5 | 912 | EXPORT_SYMBOL_GPL(register_jprobes); |
3d7e3382 | 913 | |
26b31c19 MH |
914 | int __kprobes register_jprobe(struct jprobe *jp) |
915 | { | |
49ad2fd7 | 916 | return register_jprobes(&jp, 1); |
1da177e4 | 917 | } |
99081ab5 | 918 | EXPORT_SYMBOL_GPL(register_jprobe); |
1da177e4 | 919 | |
d0aaff97 | 920 | void __kprobes unregister_jprobe(struct jprobe *jp) |
1da177e4 | 921 | { |
26b31c19 MH |
922 | unregister_jprobes(&jp, 1); |
923 | } | |
99081ab5 | 924 | EXPORT_SYMBOL_GPL(unregister_jprobe); |
26b31c19 | 925 | |
26b31c19 MH |
926 | void __kprobes unregister_jprobes(struct jprobe **jps, int num) |
927 | { | |
928 | int i; | |
929 | ||
930 | if (num <= 0) | |
931 | return; | |
932 | mutex_lock(&kprobe_mutex); | |
933 | for (i = 0; i < num; i++) | |
934 | if (__unregister_kprobe_top(&jps[i]->kp) < 0) | |
935 | jps[i]->kp.addr = NULL; | |
936 | mutex_unlock(&kprobe_mutex); | |
937 | ||
938 | synchronize_sched(); | |
939 | for (i = 0; i < num; i++) { | |
940 | if (jps[i]->kp.addr) | |
941 | __unregister_kprobe_bottom(&jps[i]->kp); | |
942 | } | |
1da177e4 | 943 | } |
99081ab5 | 944 | EXPORT_SYMBOL_GPL(unregister_jprobes); |
1da177e4 | 945 | |
9edddaa2 | 946 | #ifdef CONFIG_KRETPROBES |
e65cefe8 AB |
947 | /* |
948 | * This kprobe pre_handler is registered with every kretprobe. When probe | |
949 | * hits it will set up the return probe. | |
950 | */ | |
951 | static int __kprobes pre_handler_kretprobe(struct kprobe *p, | |
952 | struct pt_regs *regs) | |
953 | { | |
954 | struct kretprobe *rp = container_of(p, struct kretprobe, kp); | |
ef53d9c5 S |
955 | unsigned long hash, flags = 0; |
956 | struct kretprobe_instance *ri; | |
e65cefe8 AB |
957 | |
958 | /*TODO: consider to only swap the RA after the last pre_handler fired */ | |
ef53d9c5 S |
959 | hash = hash_ptr(current, KPROBE_HASH_BITS); |
960 | spin_lock_irqsave(&rp->lock, flags); | |
4c4308cb | 961 | if (!hlist_empty(&rp->free_instances)) { |
4c4308cb | 962 | ri = hlist_entry(rp->free_instances.first, |
ef53d9c5 S |
963 | struct kretprobe_instance, hlist); |
964 | hlist_del(&ri->hlist); | |
965 | spin_unlock_irqrestore(&rp->lock, flags); | |
966 | ||
4c4308cb CH |
967 | ri->rp = rp; |
968 | ri->task = current; | |
f47cd9b5 | 969 | |
f02b8624 | 970 | if (rp->entry_handler && rp->entry_handler(ri, regs)) |
f47cd9b5 | 971 | return 0; |
f47cd9b5 | 972 | |
4c4308cb CH |
973 | arch_prepare_kretprobe(ri, regs); |
974 | ||
975 | /* XXX(hch): why is there no hlist_move_head? */ | |
ef53d9c5 S |
976 | INIT_HLIST_NODE(&ri->hlist); |
977 | kretprobe_table_lock(hash, &flags); | |
978 | hlist_add_head(&ri->hlist, &kretprobe_inst_table[hash]); | |
979 | kretprobe_table_unlock(hash, &flags); | |
980 | } else { | |
4c4308cb | 981 | rp->nmissed++; |
ef53d9c5 S |
982 | spin_unlock_irqrestore(&rp->lock, flags); |
983 | } | |
e65cefe8 AB |
984 | return 0; |
985 | } | |
986 | ||
49ad2fd7 | 987 | int __kprobes register_kretprobe(struct kretprobe *rp) |
b94cce92 HN |
988 | { |
989 | int ret = 0; | |
990 | struct kretprobe_instance *inst; | |
991 | int i; | |
b2a5cd69 | 992 | void *addr; |
f438d914 MH |
993 | |
994 | if (kretprobe_blacklist_size) { | |
b2a5cd69 MH |
995 | addr = kprobe_addr(&rp->kp); |
996 | if (!addr) | |
997 | return -EINVAL; | |
f438d914 MH |
998 | |
999 | for (i = 0; kretprobe_blacklist[i].name != NULL; i++) { | |
1000 | if (kretprobe_blacklist[i].addr == addr) | |
1001 | return -EINVAL; | |
1002 | } | |
1003 | } | |
b94cce92 HN |
1004 | |
1005 | rp->kp.pre_handler = pre_handler_kretprobe; | |
7522a842 AM |
1006 | rp->kp.post_handler = NULL; |
1007 | rp->kp.fault_handler = NULL; | |
1008 | rp->kp.break_handler = NULL; | |
b94cce92 HN |
1009 | |
1010 | /* Pre-allocate memory for max kretprobe instances */ | |
1011 | if (rp->maxactive <= 0) { | |
1012 | #ifdef CONFIG_PREEMPT | |
c2ef6661 | 1013 | rp->maxactive = max_t(unsigned int, 10, 2*num_possible_cpus()); |
b94cce92 | 1014 | #else |
4dae560f | 1015 | rp->maxactive = num_possible_cpus(); |
b94cce92 HN |
1016 | #endif |
1017 | } | |
ef53d9c5 | 1018 | spin_lock_init(&rp->lock); |
b94cce92 HN |
1019 | INIT_HLIST_HEAD(&rp->free_instances); |
1020 | for (i = 0; i < rp->maxactive; i++) { | |
f47cd9b5 AS |
1021 | inst = kmalloc(sizeof(struct kretprobe_instance) + |
1022 | rp->data_size, GFP_KERNEL); | |
b94cce92 HN |
1023 | if (inst == NULL) { |
1024 | free_rp_inst(rp); | |
1025 | return -ENOMEM; | |
1026 | } | |
ef53d9c5 S |
1027 | INIT_HLIST_NODE(&inst->hlist); |
1028 | hlist_add_head(&inst->hlist, &rp->free_instances); | |
b94cce92 HN |
1029 | } |
1030 | ||
1031 | rp->nmissed = 0; | |
1032 | /* Establish function entry probe point */ | |
49ad2fd7 | 1033 | ret = register_kprobe(&rp->kp); |
4a296e07 | 1034 | if (ret != 0) |
b94cce92 HN |
1035 | free_rp_inst(rp); |
1036 | return ret; | |
1037 | } | |
99081ab5 | 1038 | EXPORT_SYMBOL_GPL(register_kretprobe); |
b94cce92 | 1039 | |
49ad2fd7 | 1040 | int __kprobes register_kretprobes(struct kretprobe **rps, int num) |
4a296e07 MH |
1041 | { |
1042 | int ret = 0, i; | |
1043 | ||
1044 | if (num <= 0) | |
1045 | return -EINVAL; | |
1046 | for (i = 0; i < num; i++) { | |
49ad2fd7 | 1047 | ret = register_kretprobe(rps[i]); |
67dddaad MH |
1048 | if (ret < 0) { |
1049 | if (i > 0) | |
1050 | unregister_kretprobes(rps, i); | |
4a296e07 MH |
1051 | break; |
1052 | } | |
1053 | } | |
1054 | return ret; | |
1055 | } | |
99081ab5 | 1056 | EXPORT_SYMBOL_GPL(register_kretprobes); |
4a296e07 | 1057 | |
4a296e07 MH |
1058 | void __kprobes unregister_kretprobe(struct kretprobe *rp) |
1059 | { | |
1060 | unregister_kretprobes(&rp, 1); | |
1061 | } | |
99081ab5 | 1062 | EXPORT_SYMBOL_GPL(unregister_kretprobe); |
4a296e07 | 1063 | |
4a296e07 MH |
1064 | void __kprobes unregister_kretprobes(struct kretprobe **rps, int num) |
1065 | { | |
1066 | int i; | |
1067 | ||
1068 | if (num <= 0) | |
1069 | return; | |
1070 | mutex_lock(&kprobe_mutex); | |
1071 | for (i = 0; i < num; i++) | |
1072 | if (__unregister_kprobe_top(&rps[i]->kp) < 0) | |
1073 | rps[i]->kp.addr = NULL; | |
1074 | mutex_unlock(&kprobe_mutex); | |
1075 | ||
1076 | synchronize_sched(); | |
1077 | for (i = 0; i < num; i++) { | |
1078 | if (rps[i]->kp.addr) { | |
1079 | __unregister_kprobe_bottom(&rps[i]->kp); | |
1080 | cleanup_rp_inst(rps[i]); | |
1081 | } | |
1082 | } | |
1083 | } | |
99081ab5 | 1084 | EXPORT_SYMBOL_GPL(unregister_kretprobes); |
4a296e07 | 1085 | |
9edddaa2 | 1086 | #else /* CONFIG_KRETPROBES */ |
d0aaff97 | 1087 | int __kprobes register_kretprobe(struct kretprobe *rp) |
b94cce92 HN |
1088 | { |
1089 | return -ENOSYS; | |
1090 | } | |
99081ab5 | 1091 | EXPORT_SYMBOL_GPL(register_kretprobe); |
b94cce92 | 1092 | |
4a296e07 | 1093 | int __kprobes register_kretprobes(struct kretprobe **rps, int num) |
346fd59b | 1094 | { |
4a296e07 | 1095 | return -ENOSYS; |
346fd59b | 1096 | } |
99081ab5 MH |
1097 | EXPORT_SYMBOL_GPL(register_kretprobes); |
1098 | ||
d0aaff97 | 1099 | void __kprobes unregister_kretprobe(struct kretprobe *rp) |
b94cce92 | 1100 | { |
4a296e07 | 1101 | } |
99081ab5 | 1102 | EXPORT_SYMBOL_GPL(unregister_kretprobe); |
b94cce92 | 1103 | |
4a296e07 MH |
1104 | void __kprobes unregister_kretprobes(struct kretprobe **rps, int num) |
1105 | { | |
1106 | } | |
99081ab5 | 1107 | EXPORT_SYMBOL_GPL(unregister_kretprobes); |
4c4308cb | 1108 | |
4a296e07 MH |
1109 | static int __kprobes pre_handler_kretprobe(struct kprobe *p, |
1110 | struct pt_regs *regs) | |
1111 | { | |
1112 | return 0; | |
b94cce92 HN |
1113 | } |
1114 | ||
4a296e07 MH |
1115 | #endif /* CONFIG_KRETPROBES */ |
1116 | ||
e8386a0c MH |
1117 | /* Set the kprobe gone and remove its instruction buffer. */ |
1118 | static void __kprobes kill_kprobe(struct kprobe *p) | |
1119 | { | |
1120 | struct kprobe *kp; | |
de5bd88d | 1121 | |
e8386a0c MH |
1122 | p->flags |= KPROBE_FLAG_GONE; |
1123 | if (p->pre_handler == aggr_pre_handler) { | |
1124 | /* | |
1125 | * If this is an aggr_kprobe, we have to list all the | |
1126 | * chained probes and mark them GONE. | |
1127 | */ | |
1128 | list_for_each_entry_rcu(kp, &p->list, list) | |
1129 | kp->flags |= KPROBE_FLAG_GONE; | |
1130 | p->post_handler = NULL; | |
1131 | p->break_handler = NULL; | |
1132 | } | |
1133 | /* | |
1134 | * Here, we can remove insn_slot safely, because no thread calls | |
1135 | * the original probed function (which will be freed soon) any more. | |
1136 | */ | |
1137 | arch_remove_kprobe(p); | |
1138 | } | |
1139 | ||
24851d24 FW |
1140 | void __kprobes dump_kprobe(struct kprobe *kp) |
1141 | { | |
1142 | printk(KERN_WARNING "Dumping kprobe:\n"); | |
1143 | printk(KERN_WARNING "Name: %s\nAddress: %p\nOffset: %x\n", | |
1144 | kp->symbol_name, kp->addr, kp->offset); | |
1145 | } | |
1146 | ||
e8386a0c MH |
1147 | /* Module notifier call back, checking kprobes on the module */ |
1148 | static int __kprobes kprobes_module_callback(struct notifier_block *nb, | |
1149 | unsigned long val, void *data) | |
1150 | { | |
1151 | struct module *mod = data; | |
1152 | struct hlist_head *head; | |
1153 | struct hlist_node *node; | |
1154 | struct kprobe *p; | |
1155 | unsigned int i; | |
f24659d9 | 1156 | int checkcore = (val == MODULE_STATE_GOING); |
e8386a0c | 1157 | |
f24659d9 | 1158 | if (val != MODULE_STATE_GOING && val != MODULE_STATE_LIVE) |
e8386a0c MH |
1159 | return NOTIFY_DONE; |
1160 | ||
1161 | /* | |
f24659d9 MH |
1162 | * When MODULE_STATE_GOING was notified, both of module .text and |
1163 | * .init.text sections would be freed. When MODULE_STATE_LIVE was | |
1164 | * notified, only .init.text section would be freed. We need to | |
1165 | * disable kprobes which have been inserted in the sections. | |
e8386a0c MH |
1166 | */ |
1167 | mutex_lock(&kprobe_mutex); | |
1168 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { | |
1169 | head = &kprobe_table[i]; | |
1170 | hlist_for_each_entry_rcu(p, node, head, hlist) | |
f24659d9 MH |
1171 | if (within_module_init((unsigned long)p->addr, mod) || |
1172 | (checkcore && | |
1173 | within_module_core((unsigned long)p->addr, mod))) { | |
e8386a0c MH |
1174 | /* |
1175 | * The vaddr this probe is installed will soon | |
1176 | * be vfreed buy not synced to disk. Hence, | |
1177 | * disarming the breakpoint isn't needed. | |
1178 | */ | |
1179 | kill_kprobe(p); | |
1180 | } | |
1181 | } | |
1182 | mutex_unlock(&kprobe_mutex); | |
1183 | return NOTIFY_DONE; | |
1184 | } | |
1185 | ||
1186 | static struct notifier_block kprobe_module_nb = { | |
1187 | .notifier_call = kprobes_module_callback, | |
1188 | .priority = 0 | |
1189 | }; | |
1190 | ||
1da177e4 LT |
1191 | static int __init init_kprobes(void) |
1192 | { | |
1193 | int i, err = 0; | |
3d8d996e SD |
1194 | unsigned long offset = 0, size = 0; |
1195 | char *modname, namebuf[128]; | |
1196 | const char *symbol_name; | |
1197 | void *addr; | |
1198 | struct kprobe_blackpoint *kb; | |
1da177e4 LT |
1199 | |
1200 | /* FIXME allocate the probe table, currently defined statically */ | |
1201 | /* initialize all list heads */ | |
b94cce92 | 1202 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
1da177e4 | 1203 | INIT_HLIST_HEAD(&kprobe_table[i]); |
b94cce92 | 1204 | INIT_HLIST_HEAD(&kretprobe_inst_table[i]); |
ef53d9c5 | 1205 | spin_lock_init(&(kretprobe_table_locks[i].lock)); |
b94cce92 | 1206 | } |
1da177e4 | 1207 | |
3d8d996e SD |
1208 | /* |
1209 | * Lookup and populate the kprobe_blacklist. | |
1210 | * | |
1211 | * Unlike the kretprobe blacklist, we'll need to determine | |
1212 | * the range of addresses that belong to the said functions, | |
1213 | * since a kprobe need not necessarily be at the beginning | |
1214 | * of a function. | |
1215 | */ | |
1216 | for (kb = kprobe_blacklist; kb->name != NULL; kb++) { | |
1217 | kprobe_lookup_name(kb->name, addr); | |
1218 | if (!addr) | |
1219 | continue; | |
1220 | ||
1221 | kb->start_addr = (unsigned long)addr; | |
1222 | symbol_name = kallsyms_lookup(kb->start_addr, | |
1223 | &size, &offset, &modname, namebuf); | |
1224 | if (!symbol_name) | |
1225 | kb->range = 0; | |
1226 | else | |
1227 | kb->range = size; | |
1228 | } | |
1229 | ||
f438d914 MH |
1230 | if (kretprobe_blacklist_size) { |
1231 | /* lookup the function address from its name */ | |
1232 | for (i = 0; kretprobe_blacklist[i].name != NULL; i++) { | |
1233 | kprobe_lookup_name(kretprobe_blacklist[i].name, | |
1234 | kretprobe_blacklist[i].addr); | |
1235 | if (!kretprobe_blacklist[i].addr) | |
1236 | printk("kretprobe: lookup failed: %s\n", | |
1237 | kretprobe_blacklist[i].name); | |
1238 | } | |
1239 | } | |
1240 | ||
e579abeb MH |
1241 | /* By default, kprobes are armed */ |
1242 | kprobes_all_disarmed = false; | |
bf8f6e5b | 1243 | |
6772926b | 1244 | err = arch_init_kprobes(); |
802eae7c RL |
1245 | if (!err) |
1246 | err = register_die_notifier(&kprobe_exceptions_nb); | |
e8386a0c MH |
1247 | if (!err) |
1248 | err = register_module_notifier(&kprobe_module_nb); | |
1249 | ||
ef53d9c5 | 1250 | kprobes_initialized = (err == 0); |
802eae7c | 1251 | |
8c1c9356 AM |
1252 | if (!err) |
1253 | init_test_probes(); | |
1da177e4 LT |
1254 | return err; |
1255 | } | |
1256 | ||
346fd59b SD |
1257 | #ifdef CONFIG_DEBUG_FS |
1258 | static void __kprobes report_probe(struct seq_file *pi, struct kprobe *p, | |
bf8f6e5b | 1259 | const char *sym, int offset,char *modname) |
346fd59b SD |
1260 | { |
1261 | char *kprobe_type; | |
1262 | ||
1263 | if (p->pre_handler == pre_handler_kretprobe) | |
1264 | kprobe_type = "r"; | |
1265 | else if (p->pre_handler == setjmp_pre_handler) | |
1266 | kprobe_type = "j"; | |
1267 | else | |
1268 | kprobe_type = "k"; | |
1269 | if (sym) | |
de5bd88d MH |
1270 | seq_printf(pi, "%p %s %s+0x%x %s %s%s\n", |
1271 | p->addr, kprobe_type, sym, offset, | |
1272 | (modname ? modname : " "), | |
1273 | (kprobe_gone(p) ? "[GONE]" : ""), | |
1274 | ((kprobe_disabled(p) && !kprobe_gone(p)) ? | |
1275 | "[DISABLED]" : "")); | |
346fd59b | 1276 | else |
de5bd88d MH |
1277 | seq_printf(pi, "%p %s %p %s%s\n", |
1278 | p->addr, kprobe_type, p->addr, | |
1279 | (kprobe_gone(p) ? "[GONE]" : ""), | |
1280 | ((kprobe_disabled(p) && !kprobe_gone(p)) ? | |
1281 | "[DISABLED]" : "")); | |
346fd59b SD |
1282 | } |
1283 | ||
1284 | static void __kprobes *kprobe_seq_start(struct seq_file *f, loff_t *pos) | |
1285 | { | |
1286 | return (*pos < KPROBE_TABLE_SIZE) ? pos : NULL; | |
1287 | } | |
1288 | ||
1289 | static void __kprobes *kprobe_seq_next(struct seq_file *f, void *v, loff_t *pos) | |
1290 | { | |
1291 | (*pos)++; | |
1292 | if (*pos >= KPROBE_TABLE_SIZE) | |
1293 | return NULL; | |
1294 | return pos; | |
1295 | } | |
1296 | ||
1297 | static void __kprobes kprobe_seq_stop(struct seq_file *f, void *v) | |
1298 | { | |
1299 | /* Nothing to do */ | |
1300 | } | |
1301 | ||
1302 | static int __kprobes show_kprobe_addr(struct seq_file *pi, void *v) | |
1303 | { | |
1304 | struct hlist_head *head; | |
1305 | struct hlist_node *node; | |
1306 | struct kprobe *p, *kp; | |
1307 | const char *sym = NULL; | |
1308 | unsigned int i = *(loff_t *) v; | |
ffb45122 | 1309 | unsigned long offset = 0; |
346fd59b SD |
1310 | char *modname, namebuf[128]; |
1311 | ||
1312 | head = &kprobe_table[i]; | |
1313 | preempt_disable(); | |
1314 | hlist_for_each_entry_rcu(p, node, head, hlist) { | |
ffb45122 | 1315 | sym = kallsyms_lookup((unsigned long)p->addr, NULL, |
346fd59b SD |
1316 | &offset, &modname, namebuf); |
1317 | if (p->pre_handler == aggr_pre_handler) { | |
1318 | list_for_each_entry_rcu(kp, &p->list, list) | |
1319 | report_probe(pi, kp, sym, offset, modname); | |
1320 | } else | |
1321 | report_probe(pi, p, sym, offset, modname); | |
1322 | } | |
1323 | preempt_enable(); | |
1324 | return 0; | |
1325 | } | |
1326 | ||
88e9d34c | 1327 | static const struct seq_operations kprobes_seq_ops = { |
346fd59b SD |
1328 | .start = kprobe_seq_start, |
1329 | .next = kprobe_seq_next, | |
1330 | .stop = kprobe_seq_stop, | |
1331 | .show = show_kprobe_addr | |
1332 | }; | |
1333 | ||
1334 | static int __kprobes kprobes_open(struct inode *inode, struct file *filp) | |
1335 | { | |
1336 | return seq_open(filp, &kprobes_seq_ops); | |
1337 | } | |
1338 | ||
828c0950 | 1339 | static const struct file_operations debugfs_kprobes_operations = { |
346fd59b SD |
1340 | .open = kprobes_open, |
1341 | .read = seq_read, | |
1342 | .llseek = seq_lseek, | |
1343 | .release = seq_release, | |
1344 | }; | |
1345 | ||
de5bd88d MH |
1346 | /* Disable one kprobe */ |
1347 | int __kprobes disable_kprobe(struct kprobe *kp) | |
1348 | { | |
1349 | int ret = 0; | |
1350 | struct kprobe *p; | |
1351 | ||
1352 | mutex_lock(&kprobe_mutex); | |
1353 | ||
1354 | /* Check whether specified probe is valid. */ | |
1355 | p = __get_valid_kprobe(kp); | |
1356 | if (unlikely(p == NULL)) { | |
1357 | ret = -EINVAL; | |
1358 | goto out; | |
1359 | } | |
1360 | ||
1361 | /* If the probe is already disabled (or gone), just return */ | |
1362 | if (kprobe_disabled(kp)) | |
1363 | goto out; | |
1364 | ||
1365 | kp->flags |= KPROBE_FLAG_DISABLED; | |
1366 | if (p != kp) | |
1367 | /* When kp != p, p is always enabled. */ | |
1368 | try_to_disable_aggr_kprobe(p); | |
1369 | ||
1370 | if (!kprobes_all_disarmed && kprobe_disabled(p)) | |
201517a7 | 1371 | disarm_kprobe(p); |
de5bd88d MH |
1372 | out: |
1373 | mutex_unlock(&kprobe_mutex); | |
1374 | return ret; | |
1375 | } | |
1376 | EXPORT_SYMBOL_GPL(disable_kprobe); | |
1377 | ||
1378 | /* Enable one kprobe */ | |
1379 | int __kprobes enable_kprobe(struct kprobe *kp) | |
1380 | { | |
1381 | int ret = 0; | |
1382 | struct kprobe *p; | |
1383 | ||
1384 | mutex_lock(&kprobe_mutex); | |
1385 | ||
1386 | /* Check whether specified probe is valid. */ | |
1387 | p = __get_valid_kprobe(kp); | |
1388 | if (unlikely(p == NULL)) { | |
1389 | ret = -EINVAL; | |
1390 | goto out; | |
1391 | } | |
1392 | ||
1393 | if (kprobe_gone(kp)) { | |
1394 | /* This kprobe has gone, we couldn't enable it. */ | |
1395 | ret = -EINVAL; | |
1396 | goto out; | |
1397 | } | |
1398 | ||
1399 | if (!kprobes_all_disarmed && kprobe_disabled(p)) | |
201517a7 | 1400 | arm_kprobe(p); |
de5bd88d MH |
1401 | |
1402 | p->flags &= ~KPROBE_FLAG_DISABLED; | |
1403 | if (p != kp) | |
1404 | kp->flags &= ~KPROBE_FLAG_DISABLED; | |
1405 | out: | |
1406 | mutex_unlock(&kprobe_mutex); | |
1407 | return ret; | |
1408 | } | |
1409 | EXPORT_SYMBOL_GPL(enable_kprobe); | |
1410 | ||
e579abeb | 1411 | static void __kprobes arm_all_kprobes(void) |
bf8f6e5b AM |
1412 | { |
1413 | struct hlist_head *head; | |
1414 | struct hlist_node *node; | |
1415 | struct kprobe *p; | |
1416 | unsigned int i; | |
1417 | ||
1418 | mutex_lock(&kprobe_mutex); | |
1419 | ||
e579abeb MH |
1420 | /* If kprobes are armed, just return */ |
1421 | if (!kprobes_all_disarmed) | |
bf8f6e5b AM |
1422 | goto already_enabled; |
1423 | ||
4460fdad | 1424 | mutex_lock(&text_mutex); |
bf8f6e5b AM |
1425 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
1426 | head = &kprobe_table[i]; | |
1427 | hlist_for_each_entry_rcu(p, node, head, hlist) | |
de5bd88d | 1428 | if (!kprobe_disabled(p)) |
e8386a0c | 1429 | arch_arm_kprobe(p); |
bf8f6e5b | 1430 | } |
4460fdad | 1431 | mutex_unlock(&text_mutex); |
bf8f6e5b | 1432 | |
e579abeb | 1433 | kprobes_all_disarmed = false; |
bf8f6e5b AM |
1434 | printk(KERN_INFO "Kprobes globally enabled\n"); |
1435 | ||
1436 | already_enabled: | |
1437 | mutex_unlock(&kprobe_mutex); | |
1438 | return; | |
1439 | } | |
1440 | ||
e579abeb | 1441 | static void __kprobes disarm_all_kprobes(void) |
bf8f6e5b AM |
1442 | { |
1443 | struct hlist_head *head; | |
1444 | struct hlist_node *node; | |
1445 | struct kprobe *p; | |
1446 | unsigned int i; | |
1447 | ||
1448 | mutex_lock(&kprobe_mutex); | |
1449 | ||
e579abeb MH |
1450 | /* If kprobes are already disarmed, just return */ |
1451 | if (kprobes_all_disarmed) | |
bf8f6e5b AM |
1452 | goto already_disabled; |
1453 | ||
e579abeb | 1454 | kprobes_all_disarmed = true; |
bf8f6e5b | 1455 | printk(KERN_INFO "Kprobes globally disabled\n"); |
4460fdad | 1456 | mutex_lock(&text_mutex); |
bf8f6e5b AM |
1457 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
1458 | head = &kprobe_table[i]; | |
1459 | hlist_for_each_entry_rcu(p, node, head, hlist) { | |
de5bd88d | 1460 | if (!arch_trampoline_kprobe(p) && !kprobe_disabled(p)) |
bf8f6e5b AM |
1461 | arch_disarm_kprobe(p); |
1462 | } | |
1463 | } | |
1464 | ||
4460fdad | 1465 | mutex_unlock(&text_mutex); |
bf8f6e5b AM |
1466 | mutex_unlock(&kprobe_mutex); |
1467 | /* Allow all currently running kprobes to complete */ | |
1468 | synchronize_sched(); | |
74a0b576 | 1469 | return; |
bf8f6e5b AM |
1470 | |
1471 | already_disabled: | |
1472 | mutex_unlock(&kprobe_mutex); | |
1473 | return; | |
1474 | } | |
1475 | ||
1476 | /* | |
1477 | * XXX: The debugfs bool file interface doesn't allow for callbacks | |
1478 | * when the bool state is switched. We can reuse that facility when | |
1479 | * available | |
1480 | */ | |
1481 | static ssize_t read_enabled_file_bool(struct file *file, | |
1482 | char __user *user_buf, size_t count, loff_t *ppos) | |
1483 | { | |
1484 | char buf[3]; | |
1485 | ||
e579abeb | 1486 | if (!kprobes_all_disarmed) |
bf8f6e5b AM |
1487 | buf[0] = '1'; |
1488 | else | |
1489 | buf[0] = '0'; | |
1490 | buf[1] = '\n'; | |
1491 | buf[2] = 0x00; | |
1492 | return simple_read_from_buffer(user_buf, count, ppos, buf, 2); | |
1493 | } | |
1494 | ||
1495 | static ssize_t write_enabled_file_bool(struct file *file, | |
1496 | const char __user *user_buf, size_t count, loff_t *ppos) | |
1497 | { | |
1498 | char buf[32]; | |
1499 | int buf_size; | |
1500 | ||
1501 | buf_size = min(count, (sizeof(buf)-1)); | |
1502 | if (copy_from_user(buf, user_buf, buf_size)) | |
1503 | return -EFAULT; | |
1504 | ||
1505 | switch (buf[0]) { | |
1506 | case 'y': | |
1507 | case 'Y': | |
1508 | case '1': | |
e579abeb | 1509 | arm_all_kprobes(); |
bf8f6e5b AM |
1510 | break; |
1511 | case 'n': | |
1512 | case 'N': | |
1513 | case '0': | |
e579abeb | 1514 | disarm_all_kprobes(); |
bf8f6e5b AM |
1515 | break; |
1516 | } | |
1517 | ||
1518 | return count; | |
1519 | } | |
1520 | ||
828c0950 | 1521 | static const struct file_operations fops_kp = { |
bf8f6e5b AM |
1522 | .read = read_enabled_file_bool, |
1523 | .write = write_enabled_file_bool, | |
1524 | }; | |
1525 | ||
346fd59b SD |
1526 | static int __kprobes debugfs_kprobe_init(void) |
1527 | { | |
1528 | struct dentry *dir, *file; | |
bf8f6e5b | 1529 | unsigned int value = 1; |
346fd59b SD |
1530 | |
1531 | dir = debugfs_create_dir("kprobes", NULL); | |
1532 | if (!dir) | |
1533 | return -ENOMEM; | |
1534 | ||
e3869792 | 1535 | file = debugfs_create_file("list", 0444, dir, NULL, |
346fd59b SD |
1536 | &debugfs_kprobes_operations); |
1537 | if (!file) { | |
1538 | debugfs_remove(dir); | |
1539 | return -ENOMEM; | |
1540 | } | |
1541 | ||
bf8f6e5b AM |
1542 | file = debugfs_create_file("enabled", 0600, dir, |
1543 | &value, &fops_kp); | |
1544 | if (!file) { | |
1545 | debugfs_remove(dir); | |
1546 | return -ENOMEM; | |
1547 | } | |
1548 | ||
346fd59b SD |
1549 | return 0; |
1550 | } | |
1551 | ||
1552 | late_initcall(debugfs_kprobe_init); | |
1553 | #endif /* CONFIG_DEBUG_FS */ | |
1554 | ||
1555 | module_init(init_kprobes); | |
1da177e4 | 1556 | |
99081ab5 | 1557 | /* defined in arch/.../kernel/kprobes.c */ |
1da177e4 | 1558 | EXPORT_SYMBOL_GPL(jprobe_return); |