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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> |
9984de1a | 39 | #include <linux/export.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> | |
b2be84df | 45 | #include <linux/sysctl.h> |
1eeb66a1 | 46 | #include <linux/kdebug.h> |
4460fdad | 47 | #include <linux/memory.h> |
4554dbcb | 48 | #include <linux/ftrace.h> |
afd66255 | 49 | #include <linux/cpu.h> |
bf5438fc | 50 | #include <linux/jump_label.h> |
bf8f6e5b | 51 | |
bfd45be0 | 52 | #include <asm/sections.h> |
1da177e4 LT |
53 | #include <asm/cacheflush.h> |
54 | #include <asm/errno.h> | |
7c0f6ba6 | 55 | #include <linux/uaccess.h> |
1da177e4 LT |
56 | |
57 | #define KPROBE_HASH_BITS 6 | |
58 | #define KPROBE_TABLE_SIZE (1 << KPROBE_HASH_BITS) | |
59 | ||
3a872d89 AM |
60 | |
61 | /* | |
62 | * Some oddball architectures like 64bit powerpc have function descriptors | |
63 | * so this must be overridable. | |
64 | */ | |
65 | #ifndef kprobe_lookup_name | |
66 | #define kprobe_lookup_name(name, addr) \ | |
67 | addr = ((kprobe_opcode_t *)(kallsyms_lookup_name(name))) | |
68 | #endif | |
69 | ||
ef53d9c5 | 70 | static int kprobes_initialized; |
1da177e4 | 71 | static struct hlist_head kprobe_table[KPROBE_TABLE_SIZE]; |
b94cce92 | 72 | static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE]; |
1da177e4 | 73 | |
bf8f6e5b | 74 | /* NOTE: change this value only with kprobe_mutex held */ |
e579abeb | 75 | static bool kprobes_all_disarmed; |
bf8f6e5b | 76 | |
43948f50 MH |
77 | /* This protects kprobe_table and optimizing_list */ |
78 | static DEFINE_MUTEX(kprobe_mutex); | |
e6584523 | 79 | static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL; |
ef53d9c5 | 80 | static struct { |
ec484608 | 81 | raw_spinlock_t lock ____cacheline_aligned_in_smp; |
ef53d9c5 S |
82 | } kretprobe_table_locks[KPROBE_TABLE_SIZE]; |
83 | ||
ec484608 | 84 | static raw_spinlock_t *kretprobe_table_lock_ptr(unsigned long hash) |
ef53d9c5 S |
85 | { |
86 | return &(kretprobe_table_locks[hash].lock); | |
87 | } | |
1da177e4 | 88 | |
376e2424 MH |
89 | /* Blacklist -- list of struct kprobe_blacklist_entry */ |
90 | static LIST_HEAD(kprobe_blacklist); | |
3d8d996e | 91 | |
2d14e39d | 92 | #ifdef __ARCH_WANT_KPROBES_INSN_SLOT |
9ec4b1f3 AM |
93 | /* |
94 | * kprobe->ainsn.insn points to the copy of the instruction to be | |
95 | * single-stepped. x86_64, POWER4 and above have no-exec support and | |
96 | * stepping on the instruction on a vmalloced/kmalloced/data page | |
97 | * is a recipe for disaster | |
98 | */ | |
9ec4b1f3 | 99 | struct kprobe_insn_page { |
c5cb5a2d | 100 | struct list_head list; |
9ec4b1f3 | 101 | kprobe_opcode_t *insns; /* Page of instruction slots */ |
af96397d | 102 | struct kprobe_insn_cache *cache; |
9ec4b1f3 | 103 | int nused; |
b4c6c34a | 104 | int ngarbage; |
4610ee1d | 105 | char slot_used[]; |
9ec4b1f3 AM |
106 | }; |
107 | ||
4610ee1d MH |
108 | #define KPROBE_INSN_PAGE_SIZE(slots) \ |
109 | (offsetof(struct kprobe_insn_page, slot_used) + \ | |
110 | (sizeof(char) * (slots))) | |
111 | ||
4610ee1d MH |
112 | static int slots_per_page(struct kprobe_insn_cache *c) |
113 | { | |
114 | return PAGE_SIZE/(c->insn_size * sizeof(kprobe_opcode_t)); | |
115 | } | |
116 | ||
ab40c5c6 MH |
117 | enum kprobe_slot_state { |
118 | SLOT_CLEAN = 0, | |
119 | SLOT_DIRTY = 1, | |
120 | SLOT_USED = 2, | |
121 | }; | |
122 | ||
af96397d HC |
123 | static void *alloc_insn_page(void) |
124 | { | |
125 | return module_alloc(PAGE_SIZE); | |
126 | } | |
127 | ||
128 | static void free_insn_page(void *page) | |
129 | { | |
be1f221c | 130 | module_memfree(page); |
af96397d HC |
131 | } |
132 | ||
c802d64a HC |
133 | struct kprobe_insn_cache kprobe_insn_slots = { |
134 | .mutex = __MUTEX_INITIALIZER(kprobe_insn_slots.mutex), | |
af96397d HC |
135 | .alloc = alloc_insn_page, |
136 | .free = free_insn_page, | |
4610ee1d MH |
137 | .pages = LIST_HEAD_INIT(kprobe_insn_slots.pages), |
138 | .insn_size = MAX_INSN_SIZE, | |
139 | .nr_garbage = 0, | |
140 | }; | |
55479f64 | 141 | static int collect_garbage_slots(struct kprobe_insn_cache *c); |
b4c6c34a | 142 | |
9ec4b1f3 | 143 | /** |
12941560 | 144 | * __get_insn_slot() - Find a slot on an executable page for an instruction. |
9ec4b1f3 AM |
145 | * We allocate an executable page if there's no room on existing ones. |
146 | */ | |
55479f64 | 147 | kprobe_opcode_t *__get_insn_slot(struct kprobe_insn_cache *c) |
9ec4b1f3 AM |
148 | { |
149 | struct kprobe_insn_page *kip; | |
c802d64a | 150 | kprobe_opcode_t *slot = NULL; |
9ec4b1f3 | 151 | |
c802d64a | 152 | mutex_lock(&c->mutex); |
6f716acd | 153 | retry: |
4610ee1d MH |
154 | list_for_each_entry(kip, &c->pages, list) { |
155 | if (kip->nused < slots_per_page(c)) { | |
9ec4b1f3 | 156 | int i; |
4610ee1d | 157 | for (i = 0; i < slots_per_page(c); i++) { |
ab40c5c6 MH |
158 | if (kip->slot_used[i] == SLOT_CLEAN) { |
159 | kip->slot_used[i] = SLOT_USED; | |
9ec4b1f3 | 160 | kip->nused++; |
c802d64a HC |
161 | slot = kip->insns + (i * c->insn_size); |
162 | goto out; | |
9ec4b1f3 AM |
163 | } |
164 | } | |
4610ee1d MH |
165 | /* kip->nused is broken. Fix it. */ |
166 | kip->nused = slots_per_page(c); | |
167 | WARN_ON(1); | |
9ec4b1f3 AM |
168 | } |
169 | } | |
170 | ||
b4c6c34a | 171 | /* If there are any garbage slots, collect it and try again. */ |
4610ee1d | 172 | if (c->nr_garbage && collect_garbage_slots(c) == 0) |
b4c6c34a | 173 | goto retry; |
4610ee1d MH |
174 | |
175 | /* All out of space. Need to allocate a new page. */ | |
176 | kip = kmalloc(KPROBE_INSN_PAGE_SIZE(slots_per_page(c)), GFP_KERNEL); | |
6f716acd | 177 | if (!kip) |
c802d64a | 178 | goto out; |
9ec4b1f3 AM |
179 | |
180 | /* | |
181 | * Use module_alloc so this page is within +/- 2GB of where the | |
182 | * kernel image and loaded module images reside. This is required | |
183 | * so x86_64 can correctly handle the %rip-relative fixups. | |
184 | */ | |
af96397d | 185 | kip->insns = c->alloc(); |
9ec4b1f3 AM |
186 | if (!kip->insns) { |
187 | kfree(kip); | |
c802d64a | 188 | goto out; |
9ec4b1f3 | 189 | } |
c5cb5a2d | 190 | INIT_LIST_HEAD(&kip->list); |
4610ee1d | 191 | memset(kip->slot_used, SLOT_CLEAN, slots_per_page(c)); |
ab40c5c6 | 192 | kip->slot_used[0] = SLOT_USED; |
9ec4b1f3 | 193 | kip->nused = 1; |
b4c6c34a | 194 | kip->ngarbage = 0; |
af96397d | 195 | kip->cache = c; |
4610ee1d | 196 | list_add(&kip->list, &c->pages); |
c802d64a HC |
197 | slot = kip->insns; |
198 | out: | |
199 | mutex_unlock(&c->mutex); | |
200 | return slot; | |
12941560 MH |
201 | } |
202 | ||
b4c6c34a | 203 | /* Return 1 if all garbages are collected, otherwise 0. */ |
55479f64 | 204 | static int collect_one_slot(struct kprobe_insn_page *kip, int idx) |
b4c6c34a | 205 | { |
ab40c5c6 | 206 | kip->slot_used[idx] = SLOT_CLEAN; |
b4c6c34a MH |
207 | kip->nused--; |
208 | if (kip->nused == 0) { | |
209 | /* | |
210 | * Page is no longer in use. Free it unless | |
211 | * it's the last one. We keep the last one | |
212 | * so as not to have to set it up again the | |
213 | * next time somebody inserts a probe. | |
214 | */ | |
4610ee1d | 215 | if (!list_is_singular(&kip->list)) { |
c5cb5a2d | 216 | list_del(&kip->list); |
af96397d | 217 | kip->cache->free(kip->insns); |
b4c6c34a MH |
218 | kfree(kip); |
219 | } | |
220 | return 1; | |
221 | } | |
222 | return 0; | |
223 | } | |
224 | ||
55479f64 | 225 | static int collect_garbage_slots(struct kprobe_insn_cache *c) |
b4c6c34a | 226 | { |
c5cb5a2d | 227 | struct kprobe_insn_page *kip, *next; |
b4c6c34a | 228 | |
615d0ebb MH |
229 | /* Ensure no-one is interrupted on the garbages */ |
230 | synchronize_sched(); | |
b4c6c34a | 231 | |
4610ee1d | 232 | list_for_each_entry_safe(kip, next, &c->pages, list) { |
b4c6c34a | 233 | int i; |
b4c6c34a MH |
234 | if (kip->ngarbage == 0) |
235 | continue; | |
236 | kip->ngarbage = 0; /* we will collect all garbages */ | |
4610ee1d | 237 | for (i = 0; i < slots_per_page(c); i++) { |
ab40c5c6 | 238 | if (kip->slot_used[i] == SLOT_DIRTY && |
b4c6c34a MH |
239 | collect_one_slot(kip, i)) |
240 | break; | |
241 | } | |
242 | } | |
4610ee1d | 243 | c->nr_garbage = 0; |
b4c6c34a MH |
244 | return 0; |
245 | } | |
246 | ||
55479f64 MH |
247 | void __free_insn_slot(struct kprobe_insn_cache *c, |
248 | kprobe_opcode_t *slot, int dirty) | |
9ec4b1f3 AM |
249 | { |
250 | struct kprobe_insn_page *kip; | |
9ec4b1f3 | 251 | |
c802d64a | 252 | mutex_lock(&c->mutex); |
4610ee1d | 253 | list_for_each_entry(kip, &c->pages, list) { |
83ff56f4 MH |
254 | long idx = ((long)slot - (long)kip->insns) / |
255 | (c->insn_size * sizeof(kprobe_opcode_t)); | |
4610ee1d MH |
256 | if (idx >= 0 && idx < slots_per_page(c)) { |
257 | WARN_ON(kip->slot_used[idx] != SLOT_USED); | |
b4c6c34a | 258 | if (dirty) { |
4610ee1d | 259 | kip->slot_used[idx] = SLOT_DIRTY; |
b4c6c34a | 260 | kip->ngarbage++; |
4610ee1d MH |
261 | if (++c->nr_garbage > slots_per_page(c)) |
262 | collect_garbage_slots(c); | |
c5cb5a2d | 263 | } else |
4610ee1d | 264 | collect_one_slot(kip, idx); |
c802d64a | 265 | goto out; |
9ec4b1f3 AM |
266 | } |
267 | } | |
4610ee1d MH |
268 | /* Could not free this slot. */ |
269 | WARN_ON(1); | |
c802d64a HC |
270 | out: |
271 | mutex_unlock(&c->mutex); | |
4610ee1d | 272 | } |
6f716acd | 273 | |
afd66255 MH |
274 | #ifdef CONFIG_OPTPROBES |
275 | /* For optimized_kprobe buffer */ | |
c802d64a HC |
276 | struct kprobe_insn_cache kprobe_optinsn_slots = { |
277 | .mutex = __MUTEX_INITIALIZER(kprobe_optinsn_slots.mutex), | |
af96397d HC |
278 | .alloc = alloc_insn_page, |
279 | .free = free_insn_page, | |
afd66255 MH |
280 | .pages = LIST_HEAD_INIT(kprobe_optinsn_slots.pages), |
281 | /* .insn_size is initialized later */ | |
282 | .nr_garbage = 0, | |
283 | }; | |
afd66255 | 284 | #endif |
2d14e39d | 285 | #endif |
9ec4b1f3 | 286 | |
e6584523 AM |
287 | /* We have preemption disabled.. so it is safe to use __ versions */ |
288 | static inline void set_kprobe_instance(struct kprobe *kp) | |
289 | { | |
b76834bc | 290 | __this_cpu_write(kprobe_instance, kp); |
e6584523 AM |
291 | } |
292 | ||
293 | static inline void reset_kprobe_instance(void) | |
294 | { | |
b76834bc | 295 | __this_cpu_write(kprobe_instance, NULL); |
e6584523 AM |
296 | } |
297 | ||
3516a460 AM |
298 | /* |
299 | * This routine is called either: | |
49a2a1b8 | 300 | * - under the kprobe_mutex - during kprobe_[un]register() |
3516a460 | 301 | * OR |
d217d545 | 302 | * - with preemption disabled - from arch/xxx/kernel/kprobes.c |
3516a460 | 303 | */ |
820aede0 | 304 | struct kprobe *get_kprobe(void *addr) |
1da177e4 LT |
305 | { |
306 | struct hlist_head *head; | |
3516a460 | 307 | struct kprobe *p; |
1da177e4 LT |
308 | |
309 | head = &kprobe_table[hash_ptr(addr, KPROBE_HASH_BITS)]; | |
b67bfe0d | 310 | hlist_for_each_entry_rcu(p, head, hlist) { |
1da177e4 LT |
311 | if (p->addr == addr) |
312 | return p; | |
313 | } | |
afd66255 | 314 | |
1da177e4 LT |
315 | return NULL; |
316 | } | |
820aede0 | 317 | NOKPROBE_SYMBOL(get_kprobe); |
1da177e4 | 318 | |
820aede0 | 319 | static int aggr_pre_handler(struct kprobe *p, struct pt_regs *regs); |
afd66255 MH |
320 | |
321 | /* Return true if the kprobe is an aggregator */ | |
322 | static inline int kprobe_aggrprobe(struct kprobe *p) | |
323 | { | |
324 | return p->pre_handler == aggr_pre_handler; | |
325 | } | |
326 | ||
6274de49 MH |
327 | /* Return true(!0) if the kprobe is unused */ |
328 | static inline int kprobe_unused(struct kprobe *p) | |
329 | { | |
330 | return kprobe_aggrprobe(p) && kprobe_disabled(p) && | |
331 | list_empty(&p->list); | |
332 | } | |
333 | ||
afd66255 MH |
334 | /* |
335 | * Keep all fields in the kprobe consistent | |
336 | */ | |
6d8e40a8 | 337 | static inline void copy_kprobe(struct kprobe *ap, struct kprobe *p) |
afd66255 | 338 | { |
6d8e40a8 MH |
339 | memcpy(&p->opcode, &ap->opcode, sizeof(kprobe_opcode_t)); |
340 | memcpy(&p->ainsn, &ap->ainsn, sizeof(struct arch_specific_insn)); | |
afd66255 MH |
341 | } |
342 | ||
343 | #ifdef CONFIG_OPTPROBES | |
b2be84df MH |
344 | /* NOTE: change this value only with kprobe_mutex held */ |
345 | static bool kprobes_allow_optimization; | |
346 | ||
afd66255 MH |
347 | /* |
348 | * Call all pre_handler on the list, but ignores its return value. | |
349 | * This must be called from arch-dep optimized caller. | |
350 | */ | |
820aede0 | 351 | void opt_pre_handler(struct kprobe *p, struct pt_regs *regs) |
afd66255 MH |
352 | { |
353 | struct kprobe *kp; | |
354 | ||
355 | list_for_each_entry_rcu(kp, &p->list, list) { | |
356 | if (kp->pre_handler && likely(!kprobe_disabled(kp))) { | |
357 | set_kprobe_instance(kp); | |
358 | kp->pre_handler(kp, regs); | |
359 | } | |
360 | reset_kprobe_instance(); | |
361 | } | |
362 | } | |
820aede0 | 363 | NOKPROBE_SYMBOL(opt_pre_handler); |
afd66255 | 364 | |
6274de49 | 365 | /* Free optimized instructions and optimized_kprobe */ |
55479f64 | 366 | static void free_aggr_kprobe(struct kprobe *p) |
6274de49 MH |
367 | { |
368 | struct optimized_kprobe *op; | |
369 | ||
370 | op = container_of(p, struct optimized_kprobe, kp); | |
371 | arch_remove_optimized_kprobe(op); | |
372 | arch_remove_kprobe(p); | |
373 | kfree(op); | |
374 | } | |
375 | ||
afd66255 MH |
376 | /* Return true(!0) if the kprobe is ready for optimization. */ |
377 | static inline int kprobe_optready(struct kprobe *p) | |
378 | { | |
379 | struct optimized_kprobe *op; | |
380 | ||
381 | if (kprobe_aggrprobe(p)) { | |
382 | op = container_of(p, struct optimized_kprobe, kp); | |
383 | return arch_prepared_optinsn(&op->optinsn); | |
384 | } | |
385 | ||
386 | return 0; | |
387 | } | |
388 | ||
6274de49 MH |
389 | /* Return true(!0) if the kprobe is disarmed. Note: p must be on hash list */ |
390 | static inline int kprobe_disarmed(struct kprobe *p) | |
391 | { | |
392 | struct optimized_kprobe *op; | |
393 | ||
394 | /* If kprobe is not aggr/opt probe, just return kprobe is disabled */ | |
395 | if (!kprobe_aggrprobe(p)) | |
396 | return kprobe_disabled(p); | |
397 | ||
398 | op = container_of(p, struct optimized_kprobe, kp); | |
399 | ||
400 | return kprobe_disabled(p) && list_empty(&op->list); | |
401 | } | |
402 | ||
403 | /* Return true(!0) if the probe is queued on (un)optimizing lists */ | |
55479f64 | 404 | static int kprobe_queued(struct kprobe *p) |
6274de49 MH |
405 | { |
406 | struct optimized_kprobe *op; | |
407 | ||
408 | if (kprobe_aggrprobe(p)) { | |
409 | op = container_of(p, struct optimized_kprobe, kp); | |
410 | if (!list_empty(&op->list)) | |
411 | return 1; | |
412 | } | |
413 | return 0; | |
414 | } | |
415 | ||
afd66255 MH |
416 | /* |
417 | * Return an optimized kprobe whose optimizing code replaces | |
418 | * instructions including addr (exclude breakpoint). | |
419 | */ | |
55479f64 | 420 | static struct kprobe *get_optimized_kprobe(unsigned long addr) |
afd66255 MH |
421 | { |
422 | int i; | |
423 | struct kprobe *p = NULL; | |
424 | struct optimized_kprobe *op; | |
425 | ||
426 | /* Don't check i == 0, since that is a breakpoint case. */ | |
427 | for (i = 1; !p && i < MAX_OPTIMIZED_LENGTH; i++) | |
428 | p = get_kprobe((void *)(addr - i)); | |
429 | ||
430 | if (p && kprobe_optready(p)) { | |
431 | op = container_of(p, struct optimized_kprobe, kp); | |
432 | if (arch_within_optimized_kprobe(op, addr)) | |
433 | return p; | |
434 | } | |
435 | ||
436 | return NULL; | |
437 | } | |
438 | ||
439 | /* Optimization staging list, protected by kprobe_mutex */ | |
440 | static LIST_HEAD(optimizing_list); | |
6274de49 | 441 | static LIST_HEAD(unoptimizing_list); |
7b959fc5 | 442 | static LIST_HEAD(freeing_list); |
afd66255 MH |
443 | |
444 | static void kprobe_optimizer(struct work_struct *work); | |
445 | static DECLARE_DELAYED_WORK(optimizing_work, kprobe_optimizer); | |
446 | #define OPTIMIZE_DELAY 5 | |
447 | ||
61f4e13f MH |
448 | /* |
449 | * Optimize (replace a breakpoint with a jump) kprobes listed on | |
450 | * optimizing_list. | |
451 | */ | |
55479f64 | 452 | static void do_optimize_kprobes(void) |
afd66255 | 453 | { |
6274de49 MH |
454 | /* Optimization never be done when disarmed */ |
455 | if (kprobes_all_disarmed || !kprobes_allow_optimization || | |
456 | list_empty(&optimizing_list)) | |
457 | return; | |
458 | ||
afd66255 MH |
459 | /* |
460 | * The optimization/unoptimization refers online_cpus via | |
461 | * stop_machine() and cpu-hotplug modifies online_cpus. | |
462 | * And same time, text_mutex will be held in cpu-hotplug and here. | |
463 | * This combination can cause a deadlock (cpu-hotplug try to lock | |
464 | * text_mutex but stop_machine can not be done because online_cpus | |
465 | * has been changed) | |
466 | * To avoid this deadlock, we need to call get_online_cpus() | |
467 | * for preventing cpu-hotplug outside of text_mutex locking. | |
468 | */ | |
469 | get_online_cpus(); | |
470 | mutex_lock(&text_mutex); | |
cd7ebe22 | 471 | arch_optimize_kprobes(&optimizing_list); |
afd66255 MH |
472 | mutex_unlock(&text_mutex); |
473 | put_online_cpus(); | |
61f4e13f MH |
474 | } |
475 | ||
6274de49 MH |
476 | /* |
477 | * Unoptimize (replace a jump with a breakpoint and remove the breakpoint | |
478 | * if need) kprobes listed on unoptimizing_list. | |
479 | */ | |
55479f64 | 480 | static void do_unoptimize_kprobes(void) |
6274de49 MH |
481 | { |
482 | struct optimized_kprobe *op, *tmp; | |
483 | ||
484 | /* Unoptimization must be done anytime */ | |
485 | if (list_empty(&unoptimizing_list)) | |
486 | return; | |
487 | ||
488 | /* Ditto to do_optimize_kprobes */ | |
489 | get_online_cpus(); | |
490 | mutex_lock(&text_mutex); | |
7b959fc5 | 491 | arch_unoptimize_kprobes(&unoptimizing_list, &freeing_list); |
f984ba4e | 492 | /* Loop free_list for disarming */ |
7b959fc5 | 493 | list_for_each_entry_safe(op, tmp, &freeing_list, list) { |
6274de49 MH |
494 | /* Disarm probes if marked disabled */ |
495 | if (kprobe_disabled(&op->kp)) | |
496 | arch_disarm_kprobe(&op->kp); | |
497 | if (kprobe_unused(&op->kp)) { | |
498 | /* | |
499 | * Remove unused probes from hash list. After waiting | |
500 | * for synchronization, these probes are reclaimed. | |
501 | * (reclaiming is done by do_free_cleaned_kprobes.) | |
502 | */ | |
503 | hlist_del_rcu(&op->kp.hlist); | |
6274de49 MH |
504 | } else |
505 | list_del_init(&op->list); | |
506 | } | |
507 | mutex_unlock(&text_mutex); | |
508 | put_online_cpus(); | |
509 | } | |
510 | ||
511 | /* Reclaim all kprobes on the free_list */ | |
55479f64 | 512 | static void do_free_cleaned_kprobes(void) |
6274de49 MH |
513 | { |
514 | struct optimized_kprobe *op, *tmp; | |
515 | ||
7b959fc5 | 516 | list_for_each_entry_safe(op, tmp, &freeing_list, list) { |
6274de49 MH |
517 | BUG_ON(!kprobe_unused(&op->kp)); |
518 | list_del_init(&op->list); | |
519 | free_aggr_kprobe(&op->kp); | |
520 | } | |
521 | } | |
522 | ||
523 | /* Start optimizer after OPTIMIZE_DELAY passed */ | |
55479f64 | 524 | static void kick_kprobe_optimizer(void) |
6274de49 | 525 | { |
ad72b3be | 526 | schedule_delayed_work(&optimizing_work, OPTIMIZE_DELAY); |
6274de49 MH |
527 | } |
528 | ||
61f4e13f | 529 | /* Kprobe jump optimizer */ |
55479f64 | 530 | static void kprobe_optimizer(struct work_struct *work) |
61f4e13f | 531 | { |
72ef3794 | 532 | mutex_lock(&kprobe_mutex); |
61f4e13f MH |
533 | /* Lock modules while optimizing kprobes */ |
534 | mutex_lock(&module_mutex); | |
61f4e13f MH |
535 | |
536 | /* | |
6274de49 MH |
537 | * Step 1: Unoptimize kprobes and collect cleaned (unused and disarmed) |
538 | * kprobes before waiting for quiesence period. | |
539 | */ | |
7b959fc5 | 540 | do_unoptimize_kprobes(); |
6274de49 MH |
541 | |
542 | /* | |
543 | * Step 2: Wait for quiesence period to ensure all running interrupts | |
61f4e13f MH |
544 | * are done. Because optprobe may modify multiple instructions |
545 | * there is a chance that Nth instruction is interrupted. In that | |
546 | * case, running interrupt can return to 2nd-Nth byte of jump | |
547 | * instruction. This wait is for avoiding it. | |
548 | */ | |
549 | synchronize_sched(); | |
550 | ||
6274de49 | 551 | /* Step 3: Optimize kprobes after quiesence period */ |
61f4e13f | 552 | do_optimize_kprobes(); |
6274de49 MH |
553 | |
554 | /* Step 4: Free cleaned kprobes after quiesence period */ | |
7b959fc5 | 555 | do_free_cleaned_kprobes(); |
6274de49 | 556 | |
afd66255 | 557 | mutex_unlock(&module_mutex); |
72ef3794 | 558 | mutex_unlock(&kprobe_mutex); |
6274de49 | 559 | |
cd7ebe22 | 560 | /* Step 5: Kick optimizer again if needed */ |
f984ba4e | 561 | if (!list_empty(&optimizing_list) || !list_empty(&unoptimizing_list)) |
cd7ebe22 | 562 | kick_kprobe_optimizer(); |
6274de49 MH |
563 | } |
564 | ||
565 | /* Wait for completing optimization and unoptimization */ | |
55479f64 | 566 | static void wait_for_kprobe_optimizer(void) |
6274de49 | 567 | { |
ad72b3be TH |
568 | mutex_lock(&kprobe_mutex); |
569 | ||
570 | while (!list_empty(&optimizing_list) || !list_empty(&unoptimizing_list)) { | |
571 | mutex_unlock(&kprobe_mutex); | |
572 | ||
573 | /* this will also make optimizing_work execute immmediately */ | |
574 | flush_delayed_work(&optimizing_work); | |
575 | /* @optimizing_work might not have been queued yet, relax */ | |
576 | cpu_relax(); | |
577 | ||
578 | mutex_lock(&kprobe_mutex); | |
579 | } | |
580 | ||
581 | mutex_unlock(&kprobe_mutex); | |
afd66255 MH |
582 | } |
583 | ||
584 | /* Optimize kprobe if p is ready to be optimized */ | |
55479f64 | 585 | static void optimize_kprobe(struct kprobe *p) |
afd66255 MH |
586 | { |
587 | struct optimized_kprobe *op; | |
588 | ||
589 | /* Check if the kprobe is disabled or not ready for optimization. */ | |
b2be84df | 590 | if (!kprobe_optready(p) || !kprobes_allow_optimization || |
afd66255 MH |
591 | (kprobe_disabled(p) || kprobes_all_disarmed)) |
592 | return; | |
593 | ||
594 | /* Both of break_handler and post_handler are not supported. */ | |
595 | if (p->break_handler || p->post_handler) | |
596 | return; | |
597 | ||
598 | op = container_of(p, struct optimized_kprobe, kp); | |
599 | ||
600 | /* Check there is no other kprobes at the optimized instructions */ | |
601 | if (arch_check_optimized_kprobe(op) < 0) | |
602 | return; | |
603 | ||
604 | /* Check if it is already optimized. */ | |
605 | if (op->kp.flags & KPROBE_FLAG_OPTIMIZED) | |
606 | return; | |
afd66255 | 607 | op->kp.flags |= KPROBE_FLAG_OPTIMIZED; |
6274de49 MH |
608 | |
609 | if (!list_empty(&op->list)) | |
610 | /* This is under unoptimizing. Just dequeue the probe */ | |
611 | list_del_init(&op->list); | |
612 | else { | |
613 | list_add(&op->list, &optimizing_list); | |
614 | kick_kprobe_optimizer(); | |
615 | } | |
616 | } | |
617 | ||
618 | /* Short cut to direct unoptimizing */ | |
55479f64 | 619 | static void force_unoptimize_kprobe(struct optimized_kprobe *op) |
6274de49 MH |
620 | { |
621 | get_online_cpus(); | |
622 | arch_unoptimize_kprobe(op); | |
623 | put_online_cpus(); | |
624 | if (kprobe_disabled(&op->kp)) | |
625 | arch_disarm_kprobe(&op->kp); | |
afd66255 MH |
626 | } |
627 | ||
628 | /* Unoptimize a kprobe if p is optimized */ | |
55479f64 | 629 | static void unoptimize_kprobe(struct kprobe *p, bool force) |
afd66255 MH |
630 | { |
631 | struct optimized_kprobe *op; | |
632 | ||
6274de49 MH |
633 | if (!kprobe_aggrprobe(p) || kprobe_disarmed(p)) |
634 | return; /* This is not an optprobe nor optimized */ | |
635 | ||
636 | op = container_of(p, struct optimized_kprobe, kp); | |
637 | if (!kprobe_optimized(p)) { | |
638 | /* Unoptimized or unoptimizing case */ | |
639 | if (force && !list_empty(&op->list)) { | |
640 | /* | |
641 | * Only if this is unoptimizing kprobe and forced, | |
642 | * forcibly unoptimize it. (No need to unoptimize | |
643 | * unoptimized kprobe again :) | |
644 | */ | |
afd66255 | 645 | list_del_init(&op->list); |
6274de49 MH |
646 | force_unoptimize_kprobe(op); |
647 | } | |
648 | return; | |
649 | } | |
650 | ||
651 | op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED; | |
652 | if (!list_empty(&op->list)) { | |
653 | /* Dequeue from the optimization queue */ | |
654 | list_del_init(&op->list); | |
655 | return; | |
656 | } | |
657 | /* Optimized kprobe case */ | |
658 | if (force) | |
659 | /* Forcibly update the code: this is a special case */ | |
660 | force_unoptimize_kprobe(op); | |
661 | else { | |
662 | list_add(&op->list, &unoptimizing_list); | |
663 | kick_kprobe_optimizer(); | |
afd66255 MH |
664 | } |
665 | } | |
666 | ||
0490cd1f MH |
667 | /* Cancel unoptimizing for reusing */ |
668 | static void reuse_unused_kprobe(struct kprobe *ap) | |
669 | { | |
670 | struct optimized_kprobe *op; | |
671 | ||
672 | BUG_ON(!kprobe_unused(ap)); | |
673 | /* | |
674 | * Unused kprobe MUST be on the way of delayed unoptimizing (means | |
675 | * there is still a relative jump) and disabled. | |
676 | */ | |
677 | op = container_of(ap, struct optimized_kprobe, kp); | |
678 | if (unlikely(list_empty(&op->list))) | |
679 | printk(KERN_WARNING "Warning: found a stray unused " | |
680 | "aggrprobe@%p\n", ap->addr); | |
681 | /* Enable the probe again */ | |
682 | ap->flags &= ~KPROBE_FLAG_DISABLED; | |
683 | /* Optimize it again (remove from op->list) */ | |
684 | BUG_ON(!kprobe_optready(ap)); | |
685 | optimize_kprobe(ap); | |
686 | } | |
687 | ||
afd66255 | 688 | /* Remove optimized instructions */ |
55479f64 | 689 | static void kill_optimized_kprobe(struct kprobe *p) |
afd66255 MH |
690 | { |
691 | struct optimized_kprobe *op; | |
692 | ||
693 | op = container_of(p, struct optimized_kprobe, kp); | |
6274de49 MH |
694 | if (!list_empty(&op->list)) |
695 | /* Dequeue from the (un)optimization queue */ | |
afd66255 | 696 | list_del_init(&op->list); |
6274de49 | 697 | op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED; |
7b959fc5 MH |
698 | |
699 | if (kprobe_unused(p)) { | |
700 | /* Enqueue if it is unused */ | |
701 | list_add(&op->list, &freeing_list); | |
702 | /* | |
703 | * Remove unused probes from the hash list. After waiting | |
704 | * for synchronization, this probe is reclaimed. | |
705 | * (reclaiming is done by do_free_cleaned_kprobes().) | |
706 | */ | |
707 | hlist_del_rcu(&op->kp.hlist); | |
708 | } | |
709 | ||
6274de49 | 710 | /* Don't touch the code, because it is already freed. */ |
afd66255 MH |
711 | arch_remove_optimized_kprobe(op); |
712 | } | |
713 | ||
714 | /* Try to prepare optimized instructions */ | |
55479f64 | 715 | static void prepare_optimized_kprobe(struct kprobe *p) |
afd66255 MH |
716 | { |
717 | struct optimized_kprobe *op; | |
718 | ||
719 | op = container_of(p, struct optimized_kprobe, kp); | |
cbf6ab52 | 720 | arch_prepare_optimized_kprobe(op, p); |
afd66255 MH |
721 | } |
722 | ||
afd66255 | 723 | /* Allocate new optimized_kprobe and try to prepare optimized instructions */ |
55479f64 | 724 | static struct kprobe *alloc_aggr_kprobe(struct kprobe *p) |
afd66255 MH |
725 | { |
726 | struct optimized_kprobe *op; | |
727 | ||
728 | op = kzalloc(sizeof(struct optimized_kprobe), GFP_KERNEL); | |
729 | if (!op) | |
730 | return NULL; | |
731 | ||
732 | INIT_LIST_HEAD(&op->list); | |
733 | op->kp.addr = p->addr; | |
cbf6ab52 | 734 | arch_prepare_optimized_kprobe(op, p); |
afd66255 MH |
735 | |
736 | return &op->kp; | |
737 | } | |
738 | ||
55479f64 | 739 | static void init_aggr_kprobe(struct kprobe *ap, struct kprobe *p); |
afd66255 MH |
740 | |
741 | /* | |
742 | * Prepare an optimized_kprobe and optimize it | |
743 | * NOTE: p must be a normal registered kprobe | |
744 | */ | |
55479f64 | 745 | static void try_to_optimize_kprobe(struct kprobe *p) |
afd66255 MH |
746 | { |
747 | struct kprobe *ap; | |
748 | struct optimized_kprobe *op; | |
749 | ||
ae6aa16f MH |
750 | /* Impossible to optimize ftrace-based kprobe */ |
751 | if (kprobe_ftrace(p)) | |
752 | return; | |
753 | ||
25764288 MH |
754 | /* For preparing optimization, jump_label_text_reserved() is called */ |
755 | jump_label_lock(); | |
756 | mutex_lock(&text_mutex); | |
757 | ||
afd66255 MH |
758 | ap = alloc_aggr_kprobe(p); |
759 | if (!ap) | |
25764288 | 760 | goto out; |
afd66255 MH |
761 | |
762 | op = container_of(ap, struct optimized_kprobe, kp); | |
763 | if (!arch_prepared_optinsn(&op->optinsn)) { | |
764 | /* If failed to setup optimizing, fallback to kprobe */ | |
6274de49 MH |
765 | arch_remove_optimized_kprobe(op); |
766 | kfree(op); | |
25764288 | 767 | goto out; |
afd66255 MH |
768 | } |
769 | ||
770 | init_aggr_kprobe(ap, p); | |
25764288 MH |
771 | optimize_kprobe(ap); /* This just kicks optimizer thread */ |
772 | ||
773 | out: | |
774 | mutex_unlock(&text_mutex); | |
775 | jump_label_unlock(); | |
afd66255 MH |
776 | } |
777 | ||
b2be84df | 778 | #ifdef CONFIG_SYSCTL |
55479f64 | 779 | static void optimize_all_kprobes(void) |
b2be84df MH |
780 | { |
781 | struct hlist_head *head; | |
b2be84df MH |
782 | struct kprobe *p; |
783 | unsigned int i; | |
784 | ||
5c51543b | 785 | mutex_lock(&kprobe_mutex); |
b2be84df MH |
786 | /* If optimization is already allowed, just return */ |
787 | if (kprobes_allow_optimization) | |
5c51543b | 788 | goto out; |
b2be84df MH |
789 | |
790 | kprobes_allow_optimization = true; | |
b2be84df MH |
791 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
792 | head = &kprobe_table[i]; | |
b67bfe0d | 793 | hlist_for_each_entry_rcu(p, head, hlist) |
b2be84df MH |
794 | if (!kprobe_disabled(p)) |
795 | optimize_kprobe(p); | |
796 | } | |
b2be84df | 797 | printk(KERN_INFO "Kprobes globally optimized\n"); |
5c51543b MH |
798 | out: |
799 | mutex_unlock(&kprobe_mutex); | |
b2be84df MH |
800 | } |
801 | ||
55479f64 | 802 | static void unoptimize_all_kprobes(void) |
b2be84df MH |
803 | { |
804 | struct hlist_head *head; | |
b2be84df MH |
805 | struct kprobe *p; |
806 | unsigned int i; | |
807 | ||
5c51543b | 808 | mutex_lock(&kprobe_mutex); |
b2be84df | 809 | /* If optimization is already prohibited, just return */ |
5c51543b MH |
810 | if (!kprobes_allow_optimization) { |
811 | mutex_unlock(&kprobe_mutex); | |
b2be84df | 812 | return; |
5c51543b | 813 | } |
b2be84df MH |
814 | |
815 | kprobes_allow_optimization = false; | |
b2be84df MH |
816 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
817 | head = &kprobe_table[i]; | |
b67bfe0d | 818 | hlist_for_each_entry_rcu(p, head, hlist) { |
b2be84df | 819 | if (!kprobe_disabled(p)) |
6274de49 | 820 | unoptimize_kprobe(p, false); |
b2be84df MH |
821 | } |
822 | } | |
5c51543b MH |
823 | mutex_unlock(&kprobe_mutex); |
824 | ||
6274de49 MH |
825 | /* Wait for unoptimizing completion */ |
826 | wait_for_kprobe_optimizer(); | |
827 | printk(KERN_INFO "Kprobes globally unoptimized\n"); | |
b2be84df MH |
828 | } |
829 | ||
5c51543b | 830 | static DEFINE_MUTEX(kprobe_sysctl_mutex); |
b2be84df MH |
831 | int sysctl_kprobes_optimization; |
832 | int proc_kprobes_optimization_handler(struct ctl_table *table, int write, | |
833 | void __user *buffer, size_t *length, | |
834 | loff_t *ppos) | |
835 | { | |
836 | int ret; | |
837 | ||
5c51543b | 838 | mutex_lock(&kprobe_sysctl_mutex); |
b2be84df MH |
839 | sysctl_kprobes_optimization = kprobes_allow_optimization ? 1 : 0; |
840 | ret = proc_dointvec_minmax(table, write, buffer, length, ppos); | |
841 | ||
842 | if (sysctl_kprobes_optimization) | |
843 | optimize_all_kprobes(); | |
844 | else | |
845 | unoptimize_all_kprobes(); | |
5c51543b | 846 | mutex_unlock(&kprobe_sysctl_mutex); |
b2be84df MH |
847 | |
848 | return ret; | |
849 | } | |
850 | #endif /* CONFIG_SYSCTL */ | |
851 | ||
6274de49 | 852 | /* Put a breakpoint for a probe. Must be called with text_mutex locked */ |
55479f64 | 853 | static void __arm_kprobe(struct kprobe *p) |
afd66255 | 854 | { |
6d8e40a8 | 855 | struct kprobe *_p; |
afd66255 MH |
856 | |
857 | /* Check collision with other optimized kprobes */ | |
6d8e40a8 MH |
858 | _p = get_optimized_kprobe((unsigned long)p->addr); |
859 | if (unlikely(_p)) | |
6274de49 MH |
860 | /* Fallback to unoptimized kprobe */ |
861 | unoptimize_kprobe(_p, true); | |
afd66255 MH |
862 | |
863 | arch_arm_kprobe(p); | |
864 | optimize_kprobe(p); /* Try to optimize (add kprobe to a list) */ | |
865 | } | |
866 | ||
6274de49 | 867 | /* Remove the breakpoint of a probe. Must be called with text_mutex locked */ |
55479f64 | 868 | static void __disarm_kprobe(struct kprobe *p, bool reopt) |
afd66255 | 869 | { |
6d8e40a8 | 870 | struct kprobe *_p; |
afd66255 | 871 | |
69d54b91 WN |
872 | /* Try to unoptimize */ |
873 | unoptimize_kprobe(p, kprobes_all_disarmed); | |
afd66255 | 874 | |
6274de49 MH |
875 | if (!kprobe_queued(p)) { |
876 | arch_disarm_kprobe(p); | |
877 | /* If another kprobe was blocked, optimize it. */ | |
878 | _p = get_optimized_kprobe((unsigned long)p->addr); | |
879 | if (unlikely(_p) && reopt) | |
880 | optimize_kprobe(_p); | |
881 | } | |
882 | /* TODO: reoptimize others after unoptimized this probe */ | |
afd66255 MH |
883 | } |
884 | ||
885 | #else /* !CONFIG_OPTPROBES */ | |
886 | ||
887 | #define optimize_kprobe(p) do {} while (0) | |
6274de49 | 888 | #define unoptimize_kprobe(p, f) do {} while (0) |
afd66255 MH |
889 | #define kill_optimized_kprobe(p) do {} while (0) |
890 | #define prepare_optimized_kprobe(p) do {} while (0) | |
891 | #define try_to_optimize_kprobe(p) do {} while (0) | |
892 | #define __arm_kprobe(p) arch_arm_kprobe(p) | |
6274de49 MH |
893 | #define __disarm_kprobe(p, o) arch_disarm_kprobe(p) |
894 | #define kprobe_disarmed(p) kprobe_disabled(p) | |
895 | #define wait_for_kprobe_optimizer() do {} while (0) | |
afd66255 | 896 | |
0490cd1f MH |
897 | /* There should be no unused kprobes can be reused without optimization */ |
898 | static void reuse_unused_kprobe(struct kprobe *ap) | |
899 | { | |
900 | printk(KERN_ERR "Error: There should be no unused kprobe here.\n"); | |
901 | BUG_ON(kprobe_unused(ap)); | |
902 | } | |
903 | ||
55479f64 | 904 | static void free_aggr_kprobe(struct kprobe *p) |
afd66255 | 905 | { |
6274de49 | 906 | arch_remove_kprobe(p); |
afd66255 MH |
907 | kfree(p); |
908 | } | |
909 | ||
55479f64 | 910 | static struct kprobe *alloc_aggr_kprobe(struct kprobe *p) |
afd66255 MH |
911 | { |
912 | return kzalloc(sizeof(struct kprobe), GFP_KERNEL); | |
913 | } | |
914 | #endif /* CONFIG_OPTPROBES */ | |
915 | ||
e7dbfe34 | 916 | #ifdef CONFIG_KPROBES_ON_FTRACE |
ae6aa16f | 917 | static struct ftrace_ops kprobe_ftrace_ops __read_mostly = { |
e5253896 | 918 | .func = kprobe_ftrace_handler, |
1d70be34 | 919 | .flags = FTRACE_OPS_FL_SAVE_REGS | FTRACE_OPS_FL_IPMODIFY, |
ae6aa16f MH |
920 | }; |
921 | static int kprobe_ftrace_enabled; | |
922 | ||
923 | /* Must ensure p->addr is really on ftrace */ | |
55479f64 | 924 | static int prepare_kprobe(struct kprobe *p) |
ae6aa16f MH |
925 | { |
926 | if (!kprobe_ftrace(p)) | |
927 | return arch_prepare_kprobe(p); | |
928 | ||
929 | return arch_prepare_kprobe_ftrace(p); | |
930 | } | |
931 | ||
932 | /* Caller must lock kprobe_mutex */ | |
55479f64 | 933 | static void arm_kprobe_ftrace(struct kprobe *p) |
ae6aa16f MH |
934 | { |
935 | int ret; | |
936 | ||
937 | ret = ftrace_set_filter_ip(&kprobe_ftrace_ops, | |
938 | (unsigned long)p->addr, 0, 0); | |
939 | WARN(ret < 0, "Failed to arm kprobe-ftrace at %p (%d)\n", p->addr, ret); | |
940 | kprobe_ftrace_enabled++; | |
941 | if (kprobe_ftrace_enabled == 1) { | |
942 | ret = register_ftrace_function(&kprobe_ftrace_ops); | |
943 | WARN(ret < 0, "Failed to init kprobe-ftrace (%d)\n", ret); | |
944 | } | |
945 | } | |
946 | ||
947 | /* Caller must lock kprobe_mutex */ | |
55479f64 | 948 | static void disarm_kprobe_ftrace(struct kprobe *p) |
ae6aa16f MH |
949 | { |
950 | int ret; | |
951 | ||
952 | kprobe_ftrace_enabled--; | |
953 | if (kprobe_ftrace_enabled == 0) { | |
954 | ret = unregister_ftrace_function(&kprobe_ftrace_ops); | |
955 | WARN(ret < 0, "Failed to init kprobe-ftrace (%d)\n", ret); | |
956 | } | |
957 | ret = ftrace_set_filter_ip(&kprobe_ftrace_ops, | |
958 | (unsigned long)p->addr, 1, 0); | |
959 | WARN(ret < 0, "Failed to disarm kprobe-ftrace at %p (%d)\n", p->addr, ret); | |
960 | } | |
e7dbfe34 | 961 | #else /* !CONFIG_KPROBES_ON_FTRACE */ |
ae6aa16f MH |
962 | #define prepare_kprobe(p) arch_prepare_kprobe(p) |
963 | #define arm_kprobe_ftrace(p) do {} while (0) | |
964 | #define disarm_kprobe_ftrace(p) do {} while (0) | |
965 | #endif | |
966 | ||
201517a7 | 967 | /* Arm a kprobe with text_mutex */ |
55479f64 | 968 | static void arm_kprobe(struct kprobe *kp) |
201517a7 | 969 | { |
ae6aa16f MH |
970 | if (unlikely(kprobe_ftrace(kp))) { |
971 | arm_kprobe_ftrace(kp); | |
972 | return; | |
973 | } | |
afd66255 MH |
974 | /* |
975 | * Here, since __arm_kprobe() doesn't use stop_machine(), | |
976 | * this doesn't cause deadlock on text_mutex. So, we don't | |
977 | * need get_online_cpus(). | |
978 | */ | |
201517a7 | 979 | mutex_lock(&text_mutex); |
afd66255 | 980 | __arm_kprobe(kp); |
201517a7 MH |
981 | mutex_unlock(&text_mutex); |
982 | } | |
983 | ||
984 | /* Disarm a kprobe with text_mutex */ | |
55479f64 | 985 | static void disarm_kprobe(struct kprobe *kp, bool reopt) |
201517a7 | 986 | { |
ae6aa16f MH |
987 | if (unlikely(kprobe_ftrace(kp))) { |
988 | disarm_kprobe_ftrace(kp); | |
989 | return; | |
990 | } | |
6274de49 | 991 | /* Ditto */ |
201517a7 | 992 | mutex_lock(&text_mutex); |
ae6aa16f | 993 | __disarm_kprobe(kp, reopt); |
201517a7 MH |
994 | mutex_unlock(&text_mutex); |
995 | } | |
996 | ||
64f562c6 AM |
997 | /* |
998 | * Aggregate handlers for multiple kprobes support - these handlers | |
999 | * take care of invoking the individual kprobe handlers on p->list | |
1000 | */ | |
820aede0 | 1001 | static int aggr_pre_handler(struct kprobe *p, struct pt_regs *regs) |
64f562c6 AM |
1002 | { |
1003 | struct kprobe *kp; | |
1004 | ||
3516a460 | 1005 | list_for_each_entry_rcu(kp, &p->list, list) { |
de5bd88d | 1006 | if (kp->pre_handler && likely(!kprobe_disabled(kp))) { |
e6584523 | 1007 | set_kprobe_instance(kp); |
8b0914ea PP |
1008 | if (kp->pre_handler(kp, regs)) |
1009 | return 1; | |
64f562c6 | 1010 | } |
e6584523 | 1011 | reset_kprobe_instance(); |
64f562c6 AM |
1012 | } |
1013 | return 0; | |
1014 | } | |
820aede0 | 1015 | NOKPROBE_SYMBOL(aggr_pre_handler); |
64f562c6 | 1016 | |
820aede0 MH |
1017 | static void aggr_post_handler(struct kprobe *p, struct pt_regs *regs, |
1018 | unsigned long flags) | |
64f562c6 AM |
1019 | { |
1020 | struct kprobe *kp; | |
1021 | ||
3516a460 | 1022 | list_for_each_entry_rcu(kp, &p->list, list) { |
de5bd88d | 1023 | if (kp->post_handler && likely(!kprobe_disabled(kp))) { |
e6584523 | 1024 | set_kprobe_instance(kp); |
64f562c6 | 1025 | kp->post_handler(kp, regs, flags); |
e6584523 | 1026 | reset_kprobe_instance(); |
64f562c6 AM |
1027 | } |
1028 | } | |
64f562c6 | 1029 | } |
820aede0 | 1030 | NOKPROBE_SYMBOL(aggr_post_handler); |
64f562c6 | 1031 | |
820aede0 MH |
1032 | static int aggr_fault_handler(struct kprobe *p, struct pt_regs *regs, |
1033 | int trapnr) | |
64f562c6 | 1034 | { |
b76834bc | 1035 | struct kprobe *cur = __this_cpu_read(kprobe_instance); |
e6584523 | 1036 | |
64f562c6 AM |
1037 | /* |
1038 | * if we faulted "during" the execution of a user specified | |
1039 | * probe handler, invoke just that probe's fault handler | |
1040 | */ | |
e6584523 AM |
1041 | if (cur && cur->fault_handler) { |
1042 | if (cur->fault_handler(cur, regs, trapnr)) | |
64f562c6 AM |
1043 | return 1; |
1044 | } | |
1045 | return 0; | |
1046 | } | |
820aede0 | 1047 | NOKPROBE_SYMBOL(aggr_fault_handler); |
64f562c6 | 1048 | |
820aede0 | 1049 | static int aggr_break_handler(struct kprobe *p, struct pt_regs *regs) |
8b0914ea | 1050 | { |
b76834bc | 1051 | struct kprobe *cur = __this_cpu_read(kprobe_instance); |
e6584523 AM |
1052 | int ret = 0; |
1053 | ||
1054 | if (cur && cur->break_handler) { | |
1055 | if (cur->break_handler(cur, regs)) | |
1056 | ret = 1; | |
8b0914ea | 1057 | } |
e6584523 AM |
1058 | reset_kprobe_instance(); |
1059 | return ret; | |
8b0914ea | 1060 | } |
820aede0 | 1061 | NOKPROBE_SYMBOL(aggr_break_handler); |
8b0914ea | 1062 | |
bf8d5c52 | 1063 | /* Walks the list and increments nmissed count for multiprobe case */ |
820aede0 | 1064 | void kprobes_inc_nmissed_count(struct kprobe *p) |
bf8d5c52 KA |
1065 | { |
1066 | struct kprobe *kp; | |
afd66255 | 1067 | if (!kprobe_aggrprobe(p)) { |
bf8d5c52 KA |
1068 | p->nmissed++; |
1069 | } else { | |
1070 | list_for_each_entry_rcu(kp, &p->list, list) | |
1071 | kp->nmissed++; | |
1072 | } | |
1073 | return; | |
1074 | } | |
820aede0 | 1075 | NOKPROBE_SYMBOL(kprobes_inc_nmissed_count); |
bf8d5c52 | 1076 | |
820aede0 MH |
1077 | void recycle_rp_inst(struct kretprobe_instance *ri, |
1078 | struct hlist_head *head) | |
b94cce92 | 1079 | { |
ef53d9c5 S |
1080 | struct kretprobe *rp = ri->rp; |
1081 | ||
b94cce92 HN |
1082 | /* remove rp inst off the rprobe_inst_table */ |
1083 | hlist_del(&ri->hlist); | |
ef53d9c5 S |
1084 | INIT_HLIST_NODE(&ri->hlist); |
1085 | if (likely(rp)) { | |
ec484608 | 1086 | raw_spin_lock(&rp->lock); |
ef53d9c5 | 1087 | hlist_add_head(&ri->hlist, &rp->free_instances); |
ec484608 | 1088 | raw_spin_unlock(&rp->lock); |
b94cce92 HN |
1089 | } else |
1090 | /* Unregistering */ | |
99219a3f | 1091 | hlist_add_head(&ri->hlist, head); |
b94cce92 | 1092 | } |
820aede0 | 1093 | NOKPROBE_SYMBOL(recycle_rp_inst); |
b94cce92 | 1094 | |
820aede0 | 1095 | void kretprobe_hash_lock(struct task_struct *tsk, |
ef53d9c5 | 1096 | struct hlist_head **head, unsigned long *flags) |
635c17c2 | 1097 | __acquires(hlist_lock) |
ef53d9c5 S |
1098 | { |
1099 | unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS); | |
ec484608 | 1100 | raw_spinlock_t *hlist_lock; |
ef53d9c5 S |
1101 | |
1102 | *head = &kretprobe_inst_table[hash]; | |
1103 | hlist_lock = kretprobe_table_lock_ptr(hash); | |
ec484608 | 1104 | raw_spin_lock_irqsave(hlist_lock, *flags); |
ef53d9c5 | 1105 | } |
820aede0 | 1106 | NOKPROBE_SYMBOL(kretprobe_hash_lock); |
ef53d9c5 | 1107 | |
820aede0 MH |
1108 | static void kretprobe_table_lock(unsigned long hash, |
1109 | unsigned long *flags) | |
635c17c2 | 1110 | __acquires(hlist_lock) |
b94cce92 | 1111 | { |
ec484608 TG |
1112 | raw_spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash); |
1113 | raw_spin_lock_irqsave(hlist_lock, *flags); | |
ef53d9c5 | 1114 | } |
820aede0 | 1115 | NOKPROBE_SYMBOL(kretprobe_table_lock); |
ef53d9c5 | 1116 | |
820aede0 MH |
1117 | void kretprobe_hash_unlock(struct task_struct *tsk, |
1118 | unsigned long *flags) | |
635c17c2 | 1119 | __releases(hlist_lock) |
ef53d9c5 S |
1120 | { |
1121 | unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS); | |
ec484608 | 1122 | raw_spinlock_t *hlist_lock; |
ef53d9c5 S |
1123 | |
1124 | hlist_lock = kretprobe_table_lock_ptr(hash); | |
ec484608 | 1125 | raw_spin_unlock_irqrestore(hlist_lock, *flags); |
ef53d9c5 | 1126 | } |
820aede0 | 1127 | NOKPROBE_SYMBOL(kretprobe_hash_unlock); |
ef53d9c5 | 1128 | |
820aede0 MH |
1129 | static void kretprobe_table_unlock(unsigned long hash, |
1130 | unsigned long *flags) | |
635c17c2 | 1131 | __releases(hlist_lock) |
ef53d9c5 | 1132 | { |
ec484608 TG |
1133 | raw_spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash); |
1134 | raw_spin_unlock_irqrestore(hlist_lock, *flags); | |
b94cce92 | 1135 | } |
820aede0 | 1136 | NOKPROBE_SYMBOL(kretprobe_table_unlock); |
b94cce92 | 1137 | |
b94cce92 | 1138 | /* |
c6fd91f0 | 1139 | * This function is called from finish_task_switch when task tk becomes dead, |
1140 | * so that we can recycle any function-return probe instances associated | |
1141 | * with this task. These left over instances represent probed functions | |
1142 | * that have been called but will never return. | |
b94cce92 | 1143 | */ |
820aede0 | 1144 | void kprobe_flush_task(struct task_struct *tk) |
b94cce92 | 1145 | { |
62c27be0 | 1146 | struct kretprobe_instance *ri; |
99219a3f | 1147 | struct hlist_head *head, empty_rp; |
b67bfe0d | 1148 | struct hlist_node *tmp; |
ef53d9c5 | 1149 | unsigned long hash, flags = 0; |
802eae7c | 1150 | |
ef53d9c5 S |
1151 | if (unlikely(!kprobes_initialized)) |
1152 | /* Early boot. kretprobe_table_locks not yet initialized. */ | |
1153 | return; | |
1154 | ||
d496aab5 | 1155 | INIT_HLIST_HEAD(&empty_rp); |
ef53d9c5 S |
1156 | hash = hash_ptr(tk, KPROBE_HASH_BITS); |
1157 | head = &kretprobe_inst_table[hash]; | |
1158 | kretprobe_table_lock(hash, &flags); | |
b67bfe0d | 1159 | hlist_for_each_entry_safe(ri, tmp, head, hlist) { |
62c27be0 | 1160 | if (ri->task == tk) |
99219a3f | 1161 | recycle_rp_inst(ri, &empty_rp); |
62c27be0 | 1162 | } |
ef53d9c5 | 1163 | kretprobe_table_unlock(hash, &flags); |
b67bfe0d | 1164 | hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) { |
99219a3f | 1165 | hlist_del(&ri->hlist); |
1166 | kfree(ri); | |
1167 | } | |
b94cce92 | 1168 | } |
820aede0 | 1169 | NOKPROBE_SYMBOL(kprobe_flush_task); |
b94cce92 | 1170 | |
b94cce92 HN |
1171 | static inline void free_rp_inst(struct kretprobe *rp) |
1172 | { | |
1173 | struct kretprobe_instance *ri; | |
b67bfe0d | 1174 | struct hlist_node *next; |
4c4308cb | 1175 | |
b67bfe0d | 1176 | hlist_for_each_entry_safe(ri, next, &rp->free_instances, hlist) { |
ef53d9c5 | 1177 | hlist_del(&ri->hlist); |
b94cce92 HN |
1178 | kfree(ri); |
1179 | } | |
1180 | } | |
1181 | ||
820aede0 | 1182 | static void cleanup_rp_inst(struct kretprobe *rp) |
4a296e07 | 1183 | { |
ef53d9c5 | 1184 | unsigned long flags, hash; |
4a296e07 | 1185 | struct kretprobe_instance *ri; |
b67bfe0d | 1186 | struct hlist_node *next; |
ef53d9c5 S |
1187 | struct hlist_head *head; |
1188 | ||
4a296e07 | 1189 | /* No race here */ |
ef53d9c5 S |
1190 | for (hash = 0; hash < KPROBE_TABLE_SIZE; hash++) { |
1191 | kretprobe_table_lock(hash, &flags); | |
1192 | head = &kretprobe_inst_table[hash]; | |
b67bfe0d | 1193 | hlist_for_each_entry_safe(ri, next, head, hlist) { |
ef53d9c5 S |
1194 | if (ri->rp == rp) |
1195 | ri->rp = NULL; | |
1196 | } | |
1197 | kretprobe_table_unlock(hash, &flags); | |
4a296e07 | 1198 | } |
4a296e07 MH |
1199 | free_rp_inst(rp); |
1200 | } | |
820aede0 | 1201 | NOKPROBE_SYMBOL(cleanup_rp_inst); |
4a296e07 | 1202 | |
8b0914ea | 1203 | /* |
b918e5e6 | 1204 | * Add the new probe to ap->list. Fail if this is the |
8b0914ea PP |
1205 | * second jprobe at the address - two jprobes can't coexist |
1206 | */ | |
55479f64 | 1207 | static int add_new_kprobe(struct kprobe *ap, struct kprobe *p) |
8b0914ea | 1208 | { |
de5bd88d | 1209 | BUG_ON(kprobe_gone(ap) || kprobe_gone(p)); |
afd66255 MH |
1210 | |
1211 | if (p->break_handler || p->post_handler) | |
6274de49 | 1212 | unoptimize_kprobe(ap, true); /* Fall back to normal kprobe */ |
afd66255 | 1213 | |
8b0914ea | 1214 | if (p->break_handler) { |
b918e5e6 | 1215 | if (ap->break_handler) |
36721656 | 1216 | return -EEXIST; |
b918e5e6 MH |
1217 | list_add_tail_rcu(&p->list, &ap->list); |
1218 | ap->break_handler = aggr_break_handler; | |
8b0914ea | 1219 | } else |
b918e5e6 MH |
1220 | list_add_rcu(&p->list, &ap->list); |
1221 | if (p->post_handler && !ap->post_handler) | |
1222 | ap->post_handler = aggr_post_handler; | |
de5bd88d | 1223 | |
8b0914ea PP |
1224 | return 0; |
1225 | } | |
1226 | ||
64f562c6 AM |
1227 | /* |
1228 | * Fill in the required fields of the "manager kprobe". Replace the | |
1229 | * earlier kprobe in the hlist with the manager kprobe | |
1230 | */ | |
55479f64 | 1231 | static void init_aggr_kprobe(struct kprobe *ap, struct kprobe *p) |
64f562c6 | 1232 | { |
afd66255 | 1233 | /* Copy p's insn slot to ap */ |
8b0914ea | 1234 | copy_kprobe(p, ap); |
a9ad965e | 1235 | flush_insn_slot(ap); |
64f562c6 | 1236 | ap->addr = p->addr; |
afd66255 | 1237 | ap->flags = p->flags & ~KPROBE_FLAG_OPTIMIZED; |
64f562c6 | 1238 | ap->pre_handler = aggr_pre_handler; |
64f562c6 | 1239 | ap->fault_handler = aggr_fault_handler; |
e8386a0c MH |
1240 | /* We don't care the kprobe which has gone. */ |
1241 | if (p->post_handler && !kprobe_gone(p)) | |
36721656 | 1242 | ap->post_handler = aggr_post_handler; |
e8386a0c | 1243 | if (p->break_handler && !kprobe_gone(p)) |
36721656 | 1244 | ap->break_handler = aggr_break_handler; |
64f562c6 AM |
1245 | |
1246 | INIT_LIST_HEAD(&ap->list); | |
afd66255 | 1247 | INIT_HLIST_NODE(&ap->hlist); |
64f562c6 | 1248 | |
afd66255 | 1249 | list_add_rcu(&p->list, &ap->list); |
adad0f33 | 1250 | hlist_replace_rcu(&p->hlist, &ap->hlist); |
64f562c6 AM |
1251 | } |
1252 | ||
1253 | /* | |
1254 | * This is the second or subsequent kprobe at the address - handle | |
1255 | * the intricacies | |
64f562c6 | 1256 | */ |
55479f64 | 1257 | static int register_aggr_kprobe(struct kprobe *orig_p, struct kprobe *p) |
64f562c6 AM |
1258 | { |
1259 | int ret = 0; | |
6d8e40a8 | 1260 | struct kprobe *ap = orig_p; |
64f562c6 | 1261 | |
25764288 MH |
1262 | /* For preparing optimization, jump_label_text_reserved() is called */ |
1263 | jump_label_lock(); | |
1264 | /* | |
1265 | * Get online CPUs to avoid text_mutex deadlock.with stop machine, | |
1266 | * which is invoked by unoptimize_kprobe() in add_new_kprobe() | |
1267 | */ | |
1268 | get_online_cpus(); | |
1269 | mutex_lock(&text_mutex); | |
1270 | ||
6d8e40a8 MH |
1271 | if (!kprobe_aggrprobe(orig_p)) { |
1272 | /* If orig_p is not an aggr_kprobe, create new aggr_kprobe. */ | |
1273 | ap = alloc_aggr_kprobe(orig_p); | |
25764288 MH |
1274 | if (!ap) { |
1275 | ret = -ENOMEM; | |
1276 | goto out; | |
1277 | } | |
6d8e40a8 | 1278 | init_aggr_kprobe(ap, orig_p); |
6274de49 | 1279 | } else if (kprobe_unused(ap)) |
0490cd1f MH |
1280 | /* This probe is going to die. Rescue it */ |
1281 | reuse_unused_kprobe(ap); | |
b918e5e6 MH |
1282 | |
1283 | if (kprobe_gone(ap)) { | |
e8386a0c MH |
1284 | /* |
1285 | * Attempting to insert new probe at the same location that | |
1286 | * had a probe in the module vaddr area which already | |
1287 | * freed. So, the instruction slot has already been | |
1288 | * released. We need a new slot for the new probe. | |
1289 | */ | |
b918e5e6 | 1290 | ret = arch_prepare_kprobe(ap); |
e8386a0c | 1291 | if (ret) |
b918e5e6 MH |
1292 | /* |
1293 | * Even if fail to allocate new slot, don't need to | |
1294 | * free aggr_probe. It will be used next time, or | |
1295 | * freed by unregister_kprobe. | |
1296 | */ | |
25764288 | 1297 | goto out; |
de5bd88d | 1298 | |
afd66255 MH |
1299 | /* Prepare optimized instructions if possible. */ |
1300 | prepare_optimized_kprobe(ap); | |
1301 | ||
e8386a0c | 1302 | /* |
de5bd88d MH |
1303 | * Clear gone flag to prevent allocating new slot again, and |
1304 | * set disabled flag because it is not armed yet. | |
e8386a0c | 1305 | */ |
de5bd88d MH |
1306 | ap->flags = (ap->flags & ~KPROBE_FLAG_GONE) |
1307 | | KPROBE_FLAG_DISABLED; | |
e8386a0c | 1308 | } |
b918e5e6 | 1309 | |
afd66255 | 1310 | /* Copy ap's insn slot to p */ |
b918e5e6 | 1311 | copy_kprobe(ap, p); |
25764288 MH |
1312 | ret = add_new_kprobe(ap, p); |
1313 | ||
1314 | out: | |
1315 | mutex_unlock(&text_mutex); | |
1316 | put_online_cpus(); | |
1317 | jump_label_unlock(); | |
1318 | ||
1319 | if (ret == 0 && kprobe_disabled(ap) && !kprobe_disabled(p)) { | |
1320 | ap->flags &= ~KPROBE_FLAG_DISABLED; | |
1321 | if (!kprobes_all_disarmed) | |
1322 | /* Arm the breakpoint again. */ | |
1323 | arm_kprobe(ap); | |
1324 | } | |
1325 | return ret; | |
64f562c6 AM |
1326 | } |
1327 | ||
be8f2743 MH |
1328 | bool __weak arch_within_kprobe_blacklist(unsigned long addr) |
1329 | { | |
1330 | /* The __kprobes marked functions and entry code must not be probed */ | |
1331 | return addr >= (unsigned long)__kprobes_text_start && | |
1332 | addr < (unsigned long)__kprobes_text_end; | |
1333 | } | |
1334 | ||
e5779e8e | 1335 | bool within_kprobe_blacklist(unsigned long addr) |
d0aaff97 | 1336 | { |
376e2424 | 1337 | struct kprobe_blacklist_entry *ent; |
3d8d996e | 1338 | |
be8f2743 | 1339 | if (arch_within_kprobe_blacklist(addr)) |
376e2424 | 1340 | return true; |
3d8d996e SD |
1341 | /* |
1342 | * If there exists a kprobe_blacklist, verify and | |
1343 | * fail any probe registration in the prohibited area | |
1344 | */ | |
376e2424 MH |
1345 | list_for_each_entry(ent, &kprobe_blacklist, list) { |
1346 | if (addr >= ent->start_addr && addr < ent->end_addr) | |
1347 | return true; | |
3d8d996e | 1348 | } |
376e2424 MH |
1349 | |
1350 | return false; | |
d0aaff97 PP |
1351 | } |
1352 | ||
b2a5cd69 MH |
1353 | /* |
1354 | * If we have a symbol_name argument, look it up and add the offset field | |
1355 | * to it. This way, we can specify a relative address to a symbol. | |
bc81d48d MH |
1356 | * This returns encoded errors if it fails to look up symbol or invalid |
1357 | * combination of parameters. | |
b2a5cd69 | 1358 | */ |
55479f64 | 1359 | static kprobe_opcode_t *kprobe_addr(struct kprobe *p) |
b2a5cd69 MH |
1360 | { |
1361 | kprobe_opcode_t *addr = p->addr; | |
bc81d48d MH |
1362 | |
1363 | if ((p->symbol_name && p->addr) || | |
1364 | (!p->symbol_name && !p->addr)) | |
1365 | goto invalid; | |
1366 | ||
b2a5cd69 | 1367 | if (p->symbol_name) { |
b2a5cd69 | 1368 | kprobe_lookup_name(p->symbol_name, addr); |
bc81d48d MH |
1369 | if (!addr) |
1370 | return ERR_PTR(-ENOENT); | |
b2a5cd69 MH |
1371 | } |
1372 | ||
bc81d48d MH |
1373 | addr = (kprobe_opcode_t *)(((char *)addr) + p->offset); |
1374 | if (addr) | |
1375 | return addr; | |
1376 | ||
1377 | invalid: | |
1378 | return ERR_PTR(-EINVAL); | |
b2a5cd69 MH |
1379 | } |
1380 | ||
1f0ab409 | 1381 | /* Check passed kprobe is valid and return kprobe in kprobe_table. */ |
55479f64 | 1382 | static struct kprobe *__get_valid_kprobe(struct kprobe *p) |
1f0ab409 | 1383 | { |
6d8e40a8 | 1384 | struct kprobe *ap, *list_p; |
1f0ab409 | 1385 | |
6d8e40a8 MH |
1386 | ap = get_kprobe(p->addr); |
1387 | if (unlikely(!ap)) | |
1f0ab409 AM |
1388 | return NULL; |
1389 | ||
6d8e40a8 MH |
1390 | if (p != ap) { |
1391 | list_for_each_entry_rcu(list_p, &ap->list, list) | |
1f0ab409 AM |
1392 | if (list_p == p) |
1393 | /* kprobe p is a valid probe */ | |
1394 | goto valid; | |
1395 | return NULL; | |
1396 | } | |
1397 | valid: | |
6d8e40a8 | 1398 | return ap; |
1f0ab409 AM |
1399 | } |
1400 | ||
1401 | /* Return error if the kprobe is being re-registered */ | |
1402 | static inline int check_kprobe_rereg(struct kprobe *p) | |
1403 | { | |
1404 | int ret = 0; | |
1f0ab409 AM |
1405 | |
1406 | mutex_lock(&kprobe_mutex); | |
6d8e40a8 | 1407 | if (__get_valid_kprobe(p)) |
1f0ab409 AM |
1408 | ret = -EINVAL; |
1409 | mutex_unlock(&kprobe_mutex); | |
6d8e40a8 | 1410 | |
1f0ab409 AM |
1411 | return ret; |
1412 | } | |
1413 | ||
f7f242ff | 1414 | int __weak arch_check_ftrace_location(struct kprobe *p) |
1da177e4 | 1415 | { |
ae6aa16f MH |
1416 | unsigned long ftrace_addr; |
1417 | ||
ae6aa16f MH |
1418 | ftrace_addr = ftrace_location((unsigned long)p->addr); |
1419 | if (ftrace_addr) { | |
e7dbfe34 | 1420 | #ifdef CONFIG_KPROBES_ON_FTRACE |
ae6aa16f MH |
1421 | /* Given address is not on the instruction boundary */ |
1422 | if ((unsigned long)p->addr != ftrace_addr) | |
1423 | return -EILSEQ; | |
ae6aa16f | 1424 | p->flags |= KPROBE_FLAG_FTRACE; |
e7dbfe34 | 1425 | #else /* !CONFIG_KPROBES_ON_FTRACE */ |
ae6aa16f MH |
1426 | return -EINVAL; |
1427 | #endif | |
1428 | } | |
f7f242ff HC |
1429 | return 0; |
1430 | } | |
1431 | ||
1432 | static int check_kprobe_address_safe(struct kprobe *p, | |
1433 | struct module **probed_mod) | |
1434 | { | |
1435 | int ret; | |
1f0ab409 | 1436 | |
f7f242ff HC |
1437 | ret = arch_check_ftrace_location(p); |
1438 | if (ret) | |
1439 | return ret; | |
91bad2f8 | 1440 | jump_label_lock(); |
de31c3ca | 1441 | preempt_disable(); |
f7fa6ef0 MH |
1442 | |
1443 | /* Ensure it is not in reserved area nor out of text */ | |
ec30c5f3 | 1444 | if (!kernel_text_address((unsigned long) p->addr) || |
376e2424 | 1445 | within_kprobe_blacklist((unsigned long) p->addr) || |
f986a499 PN |
1446 | jump_label_text_reserved(p->addr, p->addr)) { |
1447 | ret = -EINVAL; | |
f7fa6ef0 | 1448 | goto out; |
f986a499 | 1449 | } |
b3e55c72 | 1450 | |
f7fa6ef0 MH |
1451 | /* Check if are we probing a module */ |
1452 | *probed_mod = __module_text_address((unsigned long) p->addr); | |
1453 | if (*probed_mod) { | |
6f716acd | 1454 | /* |
e8386a0c MH |
1455 | * We must hold a refcount of the probed module while updating |
1456 | * its code to prohibit unexpected unloading. | |
df019b1d | 1457 | */ |
f7fa6ef0 MH |
1458 | if (unlikely(!try_module_get(*probed_mod))) { |
1459 | ret = -ENOENT; | |
1460 | goto out; | |
1461 | } | |
de31c3ca | 1462 | |
f24659d9 MH |
1463 | /* |
1464 | * If the module freed .init.text, we couldn't insert | |
1465 | * kprobes in there. | |
1466 | */ | |
f7fa6ef0 MH |
1467 | if (within_module_init((unsigned long)p->addr, *probed_mod) && |
1468 | (*probed_mod)->state != MODULE_STATE_COMING) { | |
1469 | module_put(*probed_mod); | |
1470 | *probed_mod = NULL; | |
1471 | ret = -ENOENT; | |
f24659d9 | 1472 | } |
df019b1d | 1473 | } |
f7fa6ef0 | 1474 | out: |
a189d035 | 1475 | preempt_enable(); |
de31c3ca | 1476 | jump_label_unlock(); |
1da177e4 | 1477 | |
f7fa6ef0 MH |
1478 | return ret; |
1479 | } | |
1480 | ||
55479f64 | 1481 | int register_kprobe(struct kprobe *p) |
f7fa6ef0 MH |
1482 | { |
1483 | int ret; | |
1484 | struct kprobe *old_p; | |
1485 | struct module *probed_mod; | |
1486 | kprobe_opcode_t *addr; | |
1487 | ||
1488 | /* Adjust probe address from symbol */ | |
1489 | addr = kprobe_addr(p); | |
1490 | if (IS_ERR(addr)) | |
1491 | return PTR_ERR(addr); | |
1492 | p->addr = addr; | |
1493 | ||
1494 | ret = check_kprobe_rereg(p); | |
1495 | if (ret) | |
1496 | return ret; | |
1497 | ||
1498 | /* User can pass only KPROBE_FLAG_DISABLED to register_kprobe */ | |
1499 | p->flags &= KPROBE_FLAG_DISABLED; | |
3516a460 | 1500 | p->nmissed = 0; |
9861668f | 1501 | INIT_LIST_HEAD(&p->list); |
afd66255 | 1502 | |
f7fa6ef0 MH |
1503 | ret = check_kprobe_address_safe(p, &probed_mod); |
1504 | if (ret) | |
1505 | return ret; | |
1506 | ||
1507 | mutex_lock(&kprobe_mutex); | |
afd66255 | 1508 | |
64f562c6 AM |
1509 | old_p = get_kprobe(p->addr); |
1510 | if (old_p) { | |
afd66255 | 1511 | /* Since this may unoptimize old_p, locking text_mutex. */ |
64f562c6 | 1512 | ret = register_aggr_kprobe(old_p, p); |
1da177e4 LT |
1513 | goto out; |
1514 | } | |
1da177e4 | 1515 | |
25764288 | 1516 | mutex_lock(&text_mutex); /* Avoiding text modification */ |
ae6aa16f | 1517 | ret = prepare_kprobe(p); |
25764288 | 1518 | mutex_unlock(&text_mutex); |
6f716acd | 1519 | if (ret) |
afd66255 | 1520 | goto out; |
49a2a1b8 | 1521 | |
64f562c6 | 1522 | INIT_HLIST_NODE(&p->hlist); |
3516a460 | 1523 | hlist_add_head_rcu(&p->hlist, |
1da177e4 LT |
1524 | &kprobe_table[hash_ptr(p->addr, KPROBE_HASH_BITS)]); |
1525 | ||
de5bd88d | 1526 | if (!kprobes_all_disarmed && !kprobe_disabled(p)) |
25764288 | 1527 | arm_kprobe(p); |
afd66255 MH |
1528 | |
1529 | /* Try to optimize kprobe */ | |
1530 | try_to_optimize_kprobe(p); | |
74a0b576 | 1531 | |
1da177e4 | 1532 | out: |
7a7d1cf9 | 1533 | mutex_unlock(&kprobe_mutex); |
49a2a1b8 | 1534 | |
e8386a0c | 1535 | if (probed_mod) |
df019b1d | 1536 | module_put(probed_mod); |
e8386a0c | 1537 | |
1da177e4 LT |
1538 | return ret; |
1539 | } | |
99081ab5 | 1540 | EXPORT_SYMBOL_GPL(register_kprobe); |
1da177e4 | 1541 | |
6f0f1dd7 | 1542 | /* Check if all probes on the aggrprobe are disabled */ |
55479f64 | 1543 | static int aggr_kprobe_disabled(struct kprobe *ap) |
6f0f1dd7 MH |
1544 | { |
1545 | struct kprobe *kp; | |
1546 | ||
1547 | list_for_each_entry_rcu(kp, &ap->list, list) | |
1548 | if (!kprobe_disabled(kp)) | |
1549 | /* | |
1550 | * There is an active probe on the list. | |
1551 | * We can't disable this ap. | |
1552 | */ | |
1553 | return 0; | |
1554 | ||
1555 | return 1; | |
1556 | } | |
1557 | ||
1558 | /* Disable one kprobe: Make sure called under kprobe_mutex is locked */ | |
55479f64 | 1559 | static struct kprobe *__disable_kprobe(struct kprobe *p) |
6f0f1dd7 MH |
1560 | { |
1561 | struct kprobe *orig_p; | |
1562 | ||
1563 | /* Get an original kprobe for return */ | |
1564 | orig_p = __get_valid_kprobe(p); | |
1565 | if (unlikely(orig_p == NULL)) | |
1566 | return NULL; | |
1567 | ||
1568 | if (!kprobe_disabled(p)) { | |
1569 | /* Disable probe if it is a child probe */ | |
1570 | if (p != orig_p) | |
1571 | p->flags |= KPROBE_FLAG_DISABLED; | |
1572 | ||
1573 | /* Try to disarm and disable this/parent probe */ | |
1574 | if (p == orig_p || aggr_kprobe_disabled(orig_p)) { | |
69d54b91 WN |
1575 | /* |
1576 | * If kprobes_all_disarmed is set, orig_p | |
1577 | * should have already been disarmed, so | |
1578 | * skip unneed disarming process. | |
1579 | */ | |
1580 | if (!kprobes_all_disarmed) | |
1581 | disarm_kprobe(orig_p, true); | |
6f0f1dd7 MH |
1582 | orig_p->flags |= KPROBE_FLAG_DISABLED; |
1583 | } | |
1584 | } | |
1585 | ||
1586 | return orig_p; | |
1587 | } | |
1588 | ||
de5bd88d MH |
1589 | /* |
1590 | * Unregister a kprobe without a scheduler synchronization. | |
1591 | */ | |
55479f64 | 1592 | static int __unregister_kprobe_top(struct kprobe *p) |
de5bd88d | 1593 | { |
6d8e40a8 | 1594 | struct kprobe *ap, *list_p; |
de5bd88d | 1595 | |
6f0f1dd7 MH |
1596 | /* Disable kprobe. This will disarm it if needed. */ |
1597 | ap = __disable_kprobe(p); | |
6d8e40a8 | 1598 | if (ap == NULL) |
de5bd88d MH |
1599 | return -EINVAL; |
1600 | ||
6f0f1dd7 | 1601 | if (ap == p) |
bf8f6e5b | 1602 | /* |
6f0f1dd7 MH |
1603 | * This probe is an independent(and non-optimized) kprobe |
1604 | * (not an aggrprobe). Remove from the hash list. | |
bf8f6e5b | 1605 | */ |
6f0f1dd7 MH |
1606 | goto disarmed; |
1607 | ||
1608 | /* Following process expects this probe is an aggrprobe */ | |
1609 | WARN_ON(!kprobe_aggrprobe(ap)); | |
1610 | ||
6274de49 MH |
1611 | if (list_is_singular(&ap->list) && kprobe_disarmed(ap)) |
1612 | /* | |
1613 | * !disarmed could be happen if the probe is under delayed | |
1614 | * unoptimizing. | |
1615 | */ | |
6f0f1dd7 MH |
1616 | goto disarmed; |
1617 | else { | |
1618 | /* If disabling probe has special handlers, update aggrprobe */ | |
e8386a0c | 1619 | if (p->break_handler && !kprobe_gone(p)) |
6d8e40a8 | 1620 | ap->break_handler = NULL; |
e8386a0c | 1621 | if (p->post_handler && !kprobe_gone(p)) { |
6d8e40a8 | 1622 | list_for_each_entry_rcu(list_p, &ap->list, list) { |
9861668f MH |
1623 | if ((list_p != p) && (list_p->post_handler)) |
1624 | goto noclean; | |
1625 | } | |
6d8e40a8 | 1626 | ap->post_handler = NULL; |
9861668f MH |
1627 | } |
1628 | noclean: | |
6f0f1dd7 MH |
1629 | /* |
1630 | * Remove from the aggrprobe: this path will do nothing in | |
1631 | * __unregister_kprobe_bottom(). | |
1632 | */ | |
49a2a1b8 | 1633 | list_del_rcu(&p->list); |
6f0f1dd7 MH |
1634 | if (!kprobe_disabled(ap) && !kprobes_all_disarmed) |
1635 | /* | |
1636 | * Try to optimize this probe again, because post | |
1637 | * handler may have been changed. | |
1638 | */ | |
1639 | optimize_kprobe(ap); | |
49a2a1b8 | 1640 | } |
9861668f | 1641 | return 0; |
6f0f1dd7 MH |
1642 | |
1643 | disarmed: | |
6274de49 | 1644 | BUG_ON(!kprobe_disarmed(ap)); |
6f0f1dd7 MH |
1645 | hlist_del_rcu(&ap->hlist); |
1646 | return 0; | |
9861668f | 1647 | } |
3516a460 | 1648 | |
55479f64 | 1649 | static void __unregister_kprobe_bottom(struct kprobe *p) |
9861668f | 1650 | { |
6d8e40a8 | 1651 | struct kprobe *ap; |
b3e55c72 | 1652 | |
e8386a0c | 1653 | if (list_empty(&p->list)) |
6274de49 | 1654 | /* This is an independent kprobe */ |
0498b635 | 1655 | arch_remove_kprobe(p); |
e8386a0c | 1656 | else if (list_is_singular(&p->list)) { |
6274de49 | 1657 | /* This is the last child of an aggrprobe */ |
6d8e40a8 | 1658 | ap = list_entry(p->list.next, struct kprobe, list); |
e8386a0c | 1659 | list_del(&p->list); |
6d8e40a8 | 1660 | free_aggr_kprobe(ap); |
9861668f | 1661 | } |
6274de49 | 1662 | /* Otherwise, do nothing. */ |
9861668f MH |
1663 | } |
1664 | ||
55479f64 | 1665 | int register_kprobes(struct kprobe **kps, int num) |
9861668f MH |
1666 | { |
1667 | int i, ret = 0; | |
1668 | ||
1669 | if (num <= 0) | |
1670 | return -EINVAL; | |
1671 | for (i = 0; i < num; i++) { | |
49ad2fd7 | 1672 | ret = register_kprobe(kps[i]); |
67dddaad MH |
1673 | if (ret < 0) { |
1674 | if (i > 0) | |
1675 | unregister_kprobes(kps, i); | |
9861668f | 1676 | break; |
36721656 | 1677 | } |
49a2a1b8 | 1678 | } |
9861668f MH |
1679 | return ret; |
1680 | } | |
99081ab5 | 1681 | EXPORT_SYMBOL_GPL(register_kprobes); |
9861668f | 1682 | |
55479f64 | 1683 | void unregister_kprobe(struct kprobe *p) |
9861668f MH |
1684 | { |
1685 | unregister_kprobes(&p, 1); | |
1686 | } | |
99081ab5 | 1687 | EXPORT_SYMBOL_GPL(unregister_kprobe); |
9861668f | 1688 | |
55479f64 | 1689 | void unregister_kprobes(struct kprobe **kps, int num) |
9861668f MH |
1690 | { |
1691 | int i; | |
1692 | ||
1693 | if (num <= 0) | |
1694 | return; | |
1695 | mutex_lock(&kprobe_mutex); | |
1696 | for (i = 0; i < num; i++) | |
1697 | if (__unregister_kprobe_top(kps[i]) < 0) | |
1698 | kps[i]->addr = NULL; | |
1699 | mutex_unlock(&kprobe_mutex); | |
1700 | ||
1701 | synchronize_sched(); | |
1702 | for (i = 0; i < num; i++) | |
1703 | if (kps[i]->addr) | |
1704 | __unregister_kprobe_bottom(kps[i]); | |
1da177e4 | 1705 | } |
99081ab5 | 1706 | EXPORT_SYMBOL_GPL(unregister_kprobes); |
1da177e4 LT |
1707 | |
1708 | static struct notifier_block kprobe_exceptions_nb = { | |
3d5631e0 AK |
1709 | .notifier_call = kprobe_exceptions_notify, |
1710 | .priority = 0x7fffffff /* we need to be notified first */ | |
1711 | }; | |
1712 | ||
3d7e3382 ME |
1713 | unsigned long __weak arch_deref_entry_point(void *entry) |
1714 | { | |
1715 | return (unsigned long)entry; | |
1716 | } | |
1da177e4 | 1717 | |
55479f64 | 1718 | int register_jprobes(struct jprobe **jps, int num) |
1da177e4 | 1719 | { |
26b31c19 MH |
1720 | struct jprobe *jp; |
1721 | int ret = 0, i; | |
3d7e3382 | 1722 | |
26b31c19 | 1723 | if (num <= 0) |
3d7e3382 | 1724 | return -EINVAL; |
26b31c19 | 1725 | for (i = 0; i < num; i++) { |
05662bdb | 1726 | unsigned long addr, offset; |
26b31c19 MH |
1727 | jp = jps[i]; |
1728 | addr = arch_deref_entry_point(jp->entry); | |
1729 | ||
05662bdb NK |
1730 | /* Verify probepoint is a function entry point */ |
1731 | if (kallsyms_lookup_size_offset(addr, NULL, &offset) && | |
1732 | offset == 0) { | |
1733 | jp->kp.pre_handler = setjmp_pre_handler; | |
1734 | jp->kp.break_handler = longjmp_break_handler; | |
1735 | ret = register_kprobe(&jp->kp); | |
1736 | } else | |
1737 | ret = -EINVAL; | |
edbaadbe | 1738 | |
67dddaad MH |
1739 | if (ret < 0) { |
1740 | if (i > 0) | |
1741 | unregister_jprobes(jps, i); | |
26b31c19 MH |
1742 | break; |
1743 | } | |
1744 | } | |
1745 | return ret; | |
1746 | } | |
99081ab5 | 1747 | EXPORT_SYMBOL_GPL(register_jprobes); |
3d7e3382 | 1748 | |
55479f64 | 1749 | int register_jprobe(struct jprobe *jp) |
26b31c19 | 1750 | { |
49ad2fd7 | 1751 | return register_jprobes(&jp, 1); |
1da177e4 | 1752 | } |
99081ab5 | 1753 | EXPORT_SYMBOL_GPL(register_jprobe); |
1da177e4 | 1754 | |
55479f64 | 1755 | void unregister_jprobe(struct jprobe *jp) |
1da177e4 | 1756 | { |
26b31c19 MH |
1757 | unregister_jprobes(&jp, 1); |
1758 | } | |
99081ab5 | 1759 | EXPORT_SYMBOL_GPL(unregister_jprobe); |
26b31c19 | 1760 | |
55479f64 | 1761 | void unregister_jprobes(struct jprobe **jps, int num) |
26b31c19 MH |
1762 | { |
1763 | int i; | |
1764 | ||
1765 | if (num <= 0) | |
1766 | return; | |
1767 | mutex_lock(&kprobe_mutex); | |
1768 | for (i = 0; i < num; i++) | |
1769 | if (__unregister_kprobe_top(&jps[i]->kp) < 0) | |
1770 | jps[i]->kp.addr = NULL; | |
1771 | mutex_unlock(&kprobe_mutex); | |
1772 | ||
1773 | synchronize_sched(); | |
1774 | for (i = 0; i < num; i++) { | |
1775 | if (jps[i]->kp.addr) | |
1776 | __unregister_kprobe_bottom(&jps[i]->kp); | |
1777 | } | |
1da177e4 | 1778 | } |
99081ab5 | 1779 | EXPORT_SYMBOL_GPL(unregister_jprobes); |
1da177e4 | 1780 | |
9edddaa2 | 1781 | #ifdef CONFIG_KRETPROBES |
e65cefe8 AB |
1782 | /* |
1783 | * This kprobe pre_handler is registered with every kretprobe. When probe | |
1784 | * hits it will set up the return probe. | |
1785 | */ | |
820aede0 | 1786 | static int pre_handler_kretprobe(struct kprobe *p, struct pt_regs *regs) |
e65cefe8 AB |
1787 | { |
1788 | struct kretprobe *rp = container_of(p, struct kretprobe, kp); | |
ef53d9c5 S |
1789 | unsigned long hash, flags = 0; |
1790 | struct kretprobe_instance *ri; | |
e65cefe8 | 1791 | |
f96f5678 MH |
1792 | /* |
1793 | * To avoid deadlocks, prohibit return probing in NMI contexts, | |
1794 | * just skip the probe and increase the (inexact) 'nmissed' | |
1795 | * statistical counter, so that the user is informed that | |
1796 | * something happened: | |
1797 | */ | |
1798 | if (unlikely(in_nmi())) { | |
1799 | rp->nmissed++; | |
1800 | return 0; | |
1801 | } | |
1802 | ||
1803 | /* TODO: consider to only swap the RA after the last pre_handler fired */ | |
ef53d9c5 | 1804 | hash = hash_ptr(current, KPROBE_HASH_BITS); |
ec484608 | 1805 | raw_spin_lock_irqsave(&rp->lock, flags); |
4c4308cb | 1806 | if (!hlist_empty(&rp->free_instances)) { |
4c4308cb | 1807 | ri = hlist_entry(rp->free_instances.first, |
ef53d9c5 S |
1808 | struct kretprobe_instance, hlist); |
1809 | hlist_del(&ri->hlist); | |
ec484608 | 1810 | raw_spin_unlock_irqrestore(&rp->lock, flags); |
ef53d9c5 | 1811 | |
4c4308cb CH |
1812 | ri->rp = rp; |
1813 | ri->task = current; | |
f47cd9b5 | 1814 | |
55ca6140 JL |
1815 | if (rp->entry_handler && rp->entry_handler(ri, regs)) { |
1816 | raw_spin_lock_irqsave(&rp->lock, flags); | |
1817 | hlist_add_head(&ri->hlist, &rp->free_instances); | |
1818 | raw_spin_unlock_irqrestore(&rp->lock, flags); | |
f47cd9b5 | 1819 | return 0; |
55ca6140 | 1820 | } |
f47cd9b5 | 1821 | |
4c4308cb CH |
1822 | arch_prepare_kretprobe(ri, regs); |
1823 | ||
1824 | /* XXX(hch): why is there no hlist_move_head? */ | |
ef53d9c5 S |
1825 | INIT_HLIST_NODE(&ri->hlist); |
1826 | kretprobe_table_lock(hash, &flags); | |
1827 | hlist_add_head(&ri->hlist, &kretprobe_inst_table[hash]); | |
1828 | kretprobe_table_unlock(hash, &flags); | |
1829 | } else { | |
4c4308cb | 1830 | rp->nmissed++; |
ec484608 | 1831 | raw_spin_unlock_irqrestore(&rp->lock, flags); |
ef53d9c5 | 1832 | } |
e65cefe8 AB |
1833 | return 0; |
1834 | } | |
820aede0 | 1835 | NOKPROBE_SYMBOL(pre_handler_kretprobe); |
e65cefe8 | 1836 | |
55479f64 | 1837 | int register_kretprobe(struct kretprobe *rp) |
b94cce92 HN |
1838 | { |
1839 | int ret = 0; | |
1840 | struct kretprobe_instance *inst; | |
1841 | int i; | |
b2a5cd69 | 1842 | void *addr; |
f438d914 MH |
1843 | |
1844 | if (kretprobe_blacklist_size) { | |
b2a5cd69 | 1845 | addr = kprobe_addr(&rp->kp); |
bc81d48d MH |
1846 | if (IS_ERR(addr)) |
1847 | return PTR_ERR(addr); | |
f438d914 MH |
1848 | |
1849 | for (i = 0; kretprobe_blacklist[i].name != NULL; i++) { | |
1850 | if (kretprobe_blacklist[i].addr == addr) | |
1851 | return -EINVAL; | |
1852 | } | |
1853 | } | |
b94cce92 HN |
1854 | |
1855 | rp->kp.pre_handler = pre_handler_kretprobe; | |
7522a842 AM |
1856 | rp->kp.post_handler = NULL; |
1857 | rp->kp.fault_handler = NULL; | |
1858 | rp->kp.break_handler = NULL; | |
b94cce92 HN |
1859 | |
1860 | /* Pre-allocate memory for max kretprobe instances */ | |
1861 | if (rp->maxactive <= 0) { | |
1862 | #ifdef CONFIG_PREEMPT | |
c2ef6661 | 1863 | rp->maxactive = max_t(unsigned int, 10, 2*num_possible_cpus()); |
b94cce92 | 1864 | #else |
4dae560f | 1865 | rp->maxactive = num_possible_cpus(); |
b94cce92 HN |
1866 | #endif |
1867 | } | |
ec484608 | 1868 | raw_spin_lock_init(&rp->lock); |
b94cce92 HN |
1869 | INIT_HLIST_HEAD(&rp->free_instances); |
1870 | for (i = 0; i < rp->maxactive; i++) { | |
f47cd9b5 AS |
1871 | inst = kmalloc(sizeof(struct kretprobe_instance) + |
1872 | rp->data_size, GFP_KERNEL); | |
b94cce92 HN |
1873 | if (inst == NULL) { |
1874 | free_rp_inst(rp); | |
1875 | return -ENOMEM; | |
1876 | } | |
ef53d9c5 S |
1877 | INIT_HLIST_NODE(&inst->hlist); |
1878 | hlist_add_head(&inst->hlist, &rp->free_instances); | |
b94cce92 HN |
1879 | } |
1880 | ||
1881 | rp->nmissed = 0; | |
1882 | /* Establish function entry probe point */ | |
49ad2fd7 | 1883 | ret = register_kprobe(&rp->kp); |
4a296e07 | 1884 | if (ret != 0) |
b94cce92 HN |
1885 | free_rp_inst(rp); |
1886 | return ret; | |
1887 | } | |
99081ab5 | 1888 | EXPORT_SYMBOL_GPL(register_kretprobe); |
b94cce92 | 1889 | |
55479f64 | 1890 | int register_kretprobes(struct kretprobe **rps, int num) |
4a296e07 MH |
1891 | { |
1892 | int ret = 0, i; | |
1893 | ||
1894 | if (num <= 0) | |
1895 | return -EINVAL; | |
1896 | for (i = 0; i < num; i++) { | |
49ad2fd7 | 1897 | ret = register_kretprobe(rps[i]); |
67dddaad MH |
1898 | if (ret < 0) { |
1899 | if (i > 0) | |
1900 | unregister_kretprobes(rps, i); | |
4a296e07 MH |
1901 | break; |
1902 | } | |
1903 | } | |
1904 | return ret; | |
1905 | } | |
99081ab5 | 1906 | EXPORT_SYMBOL_GPL(register_kretprobes); |
4a296e07 | 1907 | |
55479f64 | 1908 | void unregister_kretprobe(struct kretprobe *rp) |
4a296e07 MH |
1909 | { |
1910 | unregister_kretprobes(&rp, 1); | |
1911 | } | |
99081ab5 | 1912 | EXPORT_SYMBOL_GPL(unregister_kretprobe); |
4a296e07 | 1913 | |
55479f64 | 1914 | void unregister_kretprobes(struct kretprobe **rps, int num) |
4a296e07 MH |
1915 | { |
1916 | int i; | |
1917 | ||
1918 | if (num <= 0) | |
1919 | return; | |
1920 | mutex_lock(&kprobe_mutex); | |
1921 | for (i = 0; i < num; i++) | |
1922 | if (__unregister_kprobe_top(&rps[i]->kp) < 0) | |
1923 | rps[i]->kp.addr = NULL; | |
1924 | mutex_unlock(&kprobe_mutex); | |
1925 | ||
1926 | synchronize_sched(); | |
1927 | for (i = 0; i < num; i++) { | |
1928 | if (rps[i]->kp.addr) { | |
1929 | __unregister_kprobe_bottom(&rps[i]->kp); | |
1930 | cleanup_rp_inst(rps[i]); | |
1931 | } | |
1932 | } | |
1933 | } | |
99081ab5 | 1934 | EXPORT_SYMBOL_GPL(unregister_kretprobes); |
4a296e07 | 1935 | |
9edddaa2 | 1936 | #else /* CONFIG_KRETPROBES */ |
55479f64 | 1937 | int register_kretprobe(struct kretprobe *rp) |
b94cce92 HN |
1938 | { |
1939 | return -ENOSYS; | |
1940 | } | |
99081ab5 | 1941 | EXPORT_SYMBOL_GPL(register_kretprobe); |
b94cce92 | 1942 | |
55479f64 | 1943 | int register_kretprobes(struct kretprobe **rps, int num) |
346fd59b | 1944 | { |
4a296e07 | 1945 | return -ENOSYS; |
346fd59b | 1946 | } |
99081ab5 MH |
1947 | EXPORT_SYMBOL_GPL(register_kretprobes); |
1948 | ||
55479f64 | 1949 | void unregister_kretprobe(struct kretprobe *rp) |
b94cce92 | 1950 | { |
4a296e07 | 1951 | } |
99081ab5 | 1952 | EXPORT_SYMBOL_GPL(unregister_kretprobe); |
b94cce92 | 1953 | |
55479f64 | 1954 | void unregister_kretprobes(struct kretprobe **rps, int num) |
4a296e07 MH |
1955 | { |
1956 | } | |
99081ab5 | 1957 | EXPORT_SYMBOL_GPL(unregister_kretprobes); |
4c4308cb | 1958 | |
820aede0 | 1959 | static int pre_handler_kretprobe(struct kprobe *p, struct pt_regs *regs) |
4a296e07 MH |
1960 | { |
1961 | return 0; | |
b94cce92 | 1962 | } |
820aede0 | 1963 | NOKPROBE_SYMBOL(pre_handler_kretprobe); |
b94cce92 | 1964 | |
4a296e07 MH |
1965 | #endif /* CONFIG_KRETPROBES */ |
1966 | ||
e8386a0c | 1967 | /* Set the kprobe gone and remove its instruction buffer. */ |
55479f64 | 1968 | static void kill_kprobe(struct kprobe *p) |
e8386a0c MH |
1969 | { |
1970 | struct kprobe *kp; | |
de5bd88d | 1971 | |
e8386a0c | 1972 | p->flags |= KPROBE_FLAG_GONE; |
afd66255 | 1973 | if (kprobe_aggrprobe(p)) { |
e8386a0c MH |
1974 | /* |
1975 | * If this is an aggr_kprobe, we have to list all the | |
1976 | * chained probes and mark them GONE. | |
1977 | */ | |
1978 | list_for_each_entry_rcu(kp, &p->list, list) | |
1979 | kp->flags |= KPROBE_FLAG_GONE; | |
1980 | p->post_handler = NULL; | |
1981 | p->break_handler = NULL; | |
afd66255 | 1982 | kill_optimized_kprobe(p); |
e8386a0c MH |
1983 | } |
1984 | /* | |
1985 | * Here, we can remove insn_slot safely, because no thread calls | |
1986 | * the original probed function (which will be freed soon) any more. | |
1987 | */ | |
1988 | arch_remove_kprobe(p); | |
1989 | } | |
1990 | ||
c0614829 | 1991 | /* Disable one kprobe */ |
55479f64 | 1992 | int disable_kprobe(struct kprobe *kp) |
c0614829 MH |
1993 | { |
1994 | int ret = 0; | |
c0614829 MH |
1995 | |
1996 | mutex_lock(&kprobe_mutex); | |
1997 | ||
6f0f1dd7 MH |
1998 | /* Disable this kprobe */ |
1999 | if (__disable_kprobe(kp) == NULL) | |
c0614829 | 2000 | ret = -EINVAL; |
c0614829 | 2001 | |
c0614829 MH |
2002 | mutex_unlock(&kprobe_mutex); |
2003 | return ret; | |
2004 | } | |
2005 | EXPORT_SYMBOL_GPL(disable_kprobe); | |
2006 | ||
2007 | /* Enable one kprobe */ | |
55479f64 | 2008 | int enable_kprobe(struct kprobe *kp) |
c0614829 MH |
2009 | { |
2010 | int ret = 0; | |
2011 | struct kprobe *p; | |
2012 | ||
2013 | mutex_lock(&kprobe_mutex); | |
2014 | ||
2015 | /* Check whether specified probe is valid. */ | |
2016 | p = __get_valid_kprobe(kp); | |
2017 | if (unlikely(p == NULL)) { | |
2018 | ret = -EINVAL; | |
2019 | goto out; | |
2020 | } | |
2021 | ||
2022 | if (kprobe_gone(kp)) { | |
2023 | /* This kprobe has gone, we couldn't enable it. */ | |
2024 | ret = -EINVAL; | |
2025 | goto out; | |
2026 | } | |
2027 | ||
2028 | if (p != kp) | |
2029 | kp->flags &= ~KPROBE_FLAG_DISABLED; | |
2030 | ||
2031 | if (!kprobes_all_disarmed && kprobe_disabled(p)) { | |
2032 | p->flags &= ~KPROBE_FLAG_DISABLED; | |
2033 | arm_kprobe(p); | |
2034 | } | |
2035 | out: | |
2036 | mutex_unlock(&kprobe_mutex); | |
2037 | return ret; | |
2038 | } | |
2039 | EXPORT_SYMBOL_GPL(enable_kprobe); | |
2040 | ||
820aede0 | 2041 | void dump_kprobe(struct kprobe *kp) |
24851d24 FW |
2042 | { |
2043 | printk(KERN_WARNING "Dumping kprobe:\n"); | |
2044 | printk(KERN_WARNING "Name: %s\nAddress: %p\nOffset: %x\n", | |
2045 | kp->symbol_name, kp->addr, kp->offset); | |
2046 | } | |
820aede0 | 2047 | NOKPROBE_SYMBOL(dump_kprobe); |
24851d24 | 2048 | |
376e2424 MH |
2049 | /* |
2050 | * Lookup and populate the kprobe_blacklist. | |
2051 | * | |
2052 | * Unlike the kretprobe blacklist, we'll need to determine | |
2053 | * the range of addresses that belong to the said functions, | |
2054 | * since a kprobe need not necessarily be at the beginning | |
2055 | * of a function. | |
2056 | */ | |
2057 | static int __init populate_kprobe_blacklist(unsigned long *start, | |
2058 | unsigned long *end) | |
2059 | { | |
2060 | unsigned long *iter; | |
2061 | struct kprobe_blacklist_entry *ent; | |
d81b4253 | 2062 | unsigned long entry, offset = 0, size = 0; |
376e2424 MH |
2063 | |
2064 | for (iter = start; iter < end; iter++) { | |
d81b4253 MH |
2065 | entry = arch_deref_entry_point((void *)*iter); |
2066 | ||
2067 | if (!kernel_text_address(entry) || | |
2068 | !kallsyms_lookup_size_offset(entry, &size, &offset)) { | |
2069 | pr_err("Failed to find blacklist at %p\n", | |
2070 | (void *)entry); | |
376e2424 MH |
2071 | continue; |
2072 | } | |
2073 | ||
2074 | ent = kmalloc(sizeof(*ent), GFP_KERNEL); | |
2075 | if (!ent) | |
2076 | return -ENOMEM; | |
d81b4253 MH |
2077 | ent->start_addr = entry; |
2078 | ent->end_addr = entry + size; | |
376e2424 MH |
2079 | INIT_LIST_HEAD(&ent->list); |
2080 | list_add_tail(&ent->list, &kprobe_blacklist); | |
2081 | } | |
2082 | return 0; | |
2083 | } | |
2084 | ||
e8386a0c | 2085 | /* Module notifier call back, checking kprobes on the module */ |
55479f64 MH |
2086 | static int kprobes_module_callback(struct notifier_block *nb, |
2087 | unsigned long val, void *data) | |
e8386a0c MH |
2088 | { |
2089 | struct module *mod = data; | |
2090 | struct hlist_head *head; | |
e8386a0c MH |
2091 | struct kprobe *p; |
2092 | unsigned int i; | |
f24659d9 | 2093 | int checkcore = (val == MODULE_STATE_GOING); |
e8386a0c | 2094 | |
f24659d9 | 2095 | if (val != MODULE_STATE_GOING && val != MODULE_STATE_LIVE) |
e8386a0c MH |
2096 | return NOTIFY_DONE; |
2097 | ||
2098 | /* | |
f24659d9 MH |
2099 | * When MODULE_STATE_GOING was notified, both of module .text and |
2100 | * .init.text sections would be freed. When MODULE_STATE_LIVE was | |
2101 | * notified, only .init.text section would be freed. We need to | |
2102 | * disable kprobes which have been inserted in the sections. | |
e8386a0c MH |
2103 | */ |
2104 | mutex_lock(&kprobe_mutex); | |
2105 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { | |
2106 | head = &kprobe_table[i]; | |
b67bfe0d | 2107 | hlist_for_each_entry_rcu(p, head, hlist) |
f24659d9 MH |
2108 | if (within_module_init((unsigned long)p->addr, mod) || |
2109 | (checkcore && | |
2110 | within_module_core((unsigned long)p->addr, mod))) { | |
e8386a0c MH |
2111 | /* |
2112 | * The vaddr this probe is installed will soon | |
2113 | * be vfreed buy not synced to disk. Hence, | |
2114 | * disarming the breakpoint isn't needed. | |
2115 | */ | |
2116 | kill_kprobe(p); | |
2117 | } | |
2118 | } | |
2119 | mutex_unlock(&kprobe_mutex); | |
2120 | return NOTIFY_DONE; | |
2121 | } | |
2122 | ||
2123 | static struct notifier_block kprobe_module_nb = { | |
2124 | .notifier_call = kprobes_module_callback, | |
2125 | .priority = 0 | |
2126 | }; | |
2127 | ||
376e2424 MH |
2128 | /* Markers of _kprobe_blacklist section */ |
2129 | extern unsigned long __start_kprobe_blacklist[]; | |
2130 | extern unsigned long __stop_kprobe_blacklist[]; | |
2131 | ||
1da177e4 LT |
2132 | static int __init init_kprobes(void) |
2133 | { | |
2134 | int i, err = 0; | |
2135 | ||
2136 | /* FIXME allocate the probe table, currently defined statically */ | |
2137 | /* initialize all list heads */ | |
b94cce92 | 2138 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
1da177e4 | 2139 | INIT_HLIST_HEAD(&kprobe_table[i]); |
b94cce92 | 2140 | INIT_HLIST_HEAD(&kretprobe_inst_table[i]); |
ec484608 | 2141 | raw_spin_lock_init(&(kretprobe_table_locks[i].lock)); |
b94cce92 | 2142 | } |
1da177e4 | 2143 | |
376e2424 MH |
2144 | err = populate_kprobe_blacklist(__start_kprobe_blacklist, |
2145 | __stop_kprobe_blacklist); | |
2146 | if (err) { | |
2147 | pr_err("kprobes: failed to populate blacklist: %d\n", err); | |
2148 | pr_err("Please take care of using kprobes.\n"); | |
3d8d996e SD |
2149 | } |
2150 | ||
f438d914 MH |
2151 | if (kretprobe_blacklist_size) { |
2152 | /* lookup the function address from its name */ | |
2153 | for (i = 0; kretprobe_blacklist[i].name != NULL; i++) { | |
2154 | kprobe_lookup_name(kretprobe_blacklist[i].name, | |
2155 | kretprobe_blacklist[i].addr); | |
2156 | if (!kretprobe_blacklist[i].addr) | |
2157 | printk("kretprobe: lookup failed: %s\n", | |
2158 | kretprobe_blacklist[i].name); | |
2159 | } | |
2160 | } | |
2161 | ||
b2be84df MH |
2162 | #if defined(CONFIG_OPTPROBES) |
2163 | #if defined(__ARCH_WANT_KPROBES_INSN_SLOT) | |
afd66255 MH |
2164 | /* Init kprobe_optinsn_slots */ |
2165 | kprobe_optinsn_slots.insn_size = MAX_OPTINSN_SIZE; | |
2166 | #endif | |
b2be84df MH |
2167 | /* By default, kprobes can be optimized */ |
2168 | kprobes_allow_optimization = true; | |
2169 | #endif | |
afd66255 | 2170 | |
e579abeb MH |
2171 | /* By default, kprobes are armed */ |
2172 | kprobes_all_disarmed = false; | |
bf8f6e5b | 2173 | |
6772926b | 2174 | err = arch_init_kprobes(); |
802eae7c RL |
2175 | if (!err) |
2176 | err = register_die_notifier(&kprobe_exceptions_nb); | |
e8386a0c MH |
2177 | if (!err) |
2178 | err = register_module_notifier(&kprobe_module_nb); | |
2179 | ||
ef53d9c5 | 2180 | kprobes_initialized = (err == 0); |
802eae7c | 2181 | |
8c1c9356 AM |
2182 | if (!err) |
2183 | init_test_probes(); | |
1da177e4 LT |
2184 | return err; |
2185 | } | |
2186 | ||
346fd59b | 2187 | #ifdef CONFIG_DEBUG_FS |
55479f64 | 2188 | static void report_probe(struct seq_file *pi, struct kprobe *p, |
afd66255 | 2189 | const char *sym, int offset, char *modname, struct kprobe *pp) |
346fd59b SD |
2190 | { |
2191 | char *kprobe_type; | |
2192 | ||
2193 | if (p->pre_handler == pre_handler_kretprobe) | |
2194 | kprobe_type = "r"; | |
2195 | else if (p->pre_handler == setjmp_pre_handler) | |
2196 | kprobe_type = "j"; | |
2197 | else | |
2198 | kprobe_type = "k"; | |
afd66255 | 2199 | |
346fd59b | 2200 | if (sym) |
afd66255 | 2201 | seq_printf(pi, "%p %s %s+0x%x %s ", |
de5bd88d | 2202 | p->addr, kprobe_type, sym, offset, |
afd66255 | 2203 | (modname ? modname : " ")); |
346fd59b | 2204 | else |
afd66255 MH |
2205 | seq_printf(pi, "%p %s %p ", |
2206 | p->addr, kprobe_type, p->addr); | |
2207 | ||
2208 | if (!pp) | |
2209 | pp = p; | |
ae6aa16f | 2210 | seq_printf(pi, "%s%s%s%s\n", |
afd66255 MH |
2211 | (kprobe_gone(p) ? "[GONE]" : ""), |
2212 | ((kprobe_disabled(p) && !kprobe_gone(p)) ? "[DISABLED]" : ""), | |
ae6aa16f MH |
2213 | (kprobe_optimized(pp) ? "[OPTIMIZED]" : ""), |
2214 | (kprobe_ftrace(pp) ? "[FTRACE]" : "")); | |
346fd59b SD |
2215 | } |
2216 | ||
55479f64 | 2217 | static void *kprobe_seq_start(struct seq_file *f, loff_t *pos) |
346fd59b SD |
2218 | { |
2219 | return (*pos < KPROBE_TABLE_SIZE) ? pos : NULL; | |
2220 | } | |
2221 | ||
55479f64 | 2222 | static void *kprobe_seq_next(struct seq_file *f, void *v, loff_t *pos) |
346fd59b SD |
2223 | { |
2224 | (*pos)++; | |
2225 | if (*pos >= KPROBE_TABLE_SIZE) | |
2226 | return NULL; | |
2227 | return pos; | |
2228 | } | |
2229 | ||
55479f64 | 2230 | static void kprobe_seq_stop(struct seq_file *f, void *v) |
346fd59b SD |
2231 | { |
2232 | /* Nothing to do */ | |
2233 | } | |
2234 | ||
55479f64 | 2235 | static int show_kprobe_addr(struct seq_file *pi, void *v) |
346fd59b SD |
2236 | { |
2237 | struct hlist_head *head; | |
346fd59b SD |
2238 | struct kprobe *p, *kp; |
2239 | const char *sym = NULL; | |
2240 | unsigned int i = *(loff_t *) v; | |
ffb45122 | 2241 | unsigned long offset = 0; |
ab767865 | 2242 | char *modname, namebuf[KSYM_NAME_LEN]; |
346fd59b SD |
2243 | |
2244 | head = &kprobe_table[i]; | |
2245 | preempt_disable(); | |
b67bfe0d | 2246 | hlist_for_each_entry_rcu(p, head, hlist) { |
ffb45122 | 2247 | sym = kallsyms_lookup((unsigned long)p->addr, NULL, |
346fd59b | 2248 | &offset, &modname, namebuf); |
afd66255 | 2249 | if (kprobe_aggrprobe(p)) { |
346fd59b | 2250 | list_for_each_entry_rcu(kp, &p->list, list) |
afd66255 | 2251 | report_probe(pi, kp, sym, offset, modname, p); |
346fd59b | 2252 | } else |
afd66255 | 2253 | report_probe(pi, p, sym, offset, modname, NULL); |
346fd59b SD |
2254 | } |
2255 | preempt_enable(); | |
2256 | return 0; | |
2257 | } | |
2258 | ||
88e9d34c | 2259 | static const struct seq_operations kprobes_seq_ops = { |
346fd59b SD |
2260 | .start = kprobe_seq_start, |
2261 | .next = kprobe_seq_next, | |
2262 | .stop = kprobe_seq_stop, | |
2263 | .show = show_kprobe_addr | |
2264 | }; | |
2265 | ||
55479f64 | 2266 | static int kprobes_open(struct inode *inode, struct file *filp) |
346fd59b SD |
2267 | { |
2268 | return seq_open(filp, &kprobes_seq_ops); | |
2269 | } | |
2270 | ||
828c0950 | 2271 | static const struct file_operations debugfs_kprobes_operations = { |
346fd59b SD |
2272 | .open = kprobes_open, |
2273 | .read = seq_read, | |
2274 | .llseek = seq_lseek, | |
2275 | .release = seq_release, | |
2276 | }; | |
2277 | ||
63724740 MH |
2278 | /* kprobes/blacklist -- shows which functions can not be probed */ |
2279 | static void *kprobe_blacklist_seq_start(struct seq_file *m, loff_t *pos) | |
2280 | { | |
2281 | return seq_list_start(&kprobe_blacklist, *pos); | |
2282 | } | |
2283 | ||
2284 | static void *kprobe_blacklist_seq_next(struct seq_file *m, void *v, loff_t *pos) | |
2285 | { | |
2286 | return seq_list_next(v, &kprobe_blacklist, pos); | |
2287 | } | |
2288 | ||
2289 | static int kprobe_blacklist_seq_show(struct seq_file *m, void *v) | |
2290 | { | |
2291 | struct kprobe_blacklist_entry *ent = | |
2292 | list_entry(v, struct kprobe_blacklist_entry, list); | |
2293 | ||
2294 | seq_printf(m, "0x%p-0x%p\t%ps\n", (void *)ent->start_addr, | |
2295 | (void *)ent->end_addr, (void *)ent->start_addr); | |
2296 | return 0; | |
2297 | } | |
2298 | ||
2299 | static const struct seq_operations kprobe_blacklist_seq_ops = { | |
2300 | .start = kprobe_blacklist_seq_start, | |
2301 | .next = kprobe_blacklist_seq_next, | |
2302 | .stop = kprobe_seq_stop, /* Reuse void function */ | |
2303 | .show = kprobe_blacklist_seq_show, | |
2304 | }; | |
2305 | ||
2306 | static int kprobe_blacklist_open(struct inode *inode, struct file *filp) | |
2307 | { | |
2308 | return seq_open(filp, &kprobe_blacklist_seq_ops); | |
2309 | } | |
2310 | ||
2311 | static const struct file_operations debugfs_kprobe_blacklist_ops = { | |
2312 | .open = kprobe_blacklist_open, | |
2313 | .read = seq_read, | |
2314 | .llseek = seq_lseek, | |
2315 | .release = seq_release, | |
2316 | }; | |
2317 | ||
55479f64 | 2318 | static void arm_all_kprobes(void) |
bf8f6e5b AM |
2319 | { |
2320 | struct hlist_head *head; | |
bf8f6e5b AM |
2321 | struct kprobe *p; |
2322 | unsigned int i; | |
2323 | ||
2324 | mutex_lock(&kprobe_mutex); | |
2325 | ||
e579abeb MH |
2326 | /* If kprobes are armed, just return */ |
2327 | if (!kprobes_all_disarmed) | |
bf8f6e5b AM |
2328 | goto already_enabled; |
2329 | ||
977ad481 WN |
2330 | /* |
2331 | * optimize_kprobe() called by arm_kprobe() checks | |
2332 | * kprobes_all_disarmed, so set kprobes_all_disarmed before | |
2333 | * arm_kprobe. | |
2334 | */ | |
2335 | kprobes_all_disarmed = false; | |
afd66255 | 2336 | /* Arming kprobes doesn't optimize kprobe itself */ |
bf8f6e5b AM |
2337 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
2338 | head = &kprobe_table[i]; | |
b67bfe0d | 2339 | hlist_for_each_entry_rcu(p, head, hlist) |
de5bd88d | 2340 | if (!kprobe_disabled(p)) |
ae6aa16f | 2341 | arm_kprobe(p); |
bf8f6e5b AM |
2342 | } |
2343 | ||
bf8f6e5b AM |
2344 | printk(KERN_INFO "Kprobes globally enabled\n"); |
2345 | ||
2346 | already_enabled: | |
2347 | mutex_unlock(&kprobe_mutex); | |
2348 | return; | |
2349 | } | |
2350 | ||
55479f64 | 2351 | static void disarm_all_kprobes(void) |
bf8f6e5b AM |
2352 | { |
2353 | struct hlist_head *head; | |
bf8f6e5b AM |
2354 | struct kprobe *p; |
2355 | unsigned int i; | |
2356 | ||
2357 | mutex_lock(&kprobe_mutex); | |
2358 | ||
e579abeb | 2359 | /* If kprobes are already disarmed, just return */ |
6274de49 MH |
2360 | if (kprobes_all_disarmed) { |
2361 | mutex_unlock(&kprobe_mutex); | |
2362 | return; | |
2363 | } | |
bf8f6e5b | 2364 | |
e579abeb | 2365 | kprobes_all_disarmed = true; |
bf8f6e5b | 2366 | printk(KERN_INFO "Kprobes globally disabled\n"); |
afd66255 | 2367 | |
bf8f6e5b AM |
2368 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
2369 | head = &kprobe_table[i]; | |
b67bfe0d | 2370 | hlist_for_each_entry_rcu(p, head, hlist) { |
de5bd88d | 2371 | if (!arch_trampoline_kprobe(p) && !kprobe_disabled(p)) |
ae6aa16f | 2372 | disarm_kprobe(p, false); |
bf8f6e5b AM |
2373 | } |
2374 | } | |
bf8f6e5b | 2375 | mutex_unlock(&kprobe_mutex); |
bf8f6e5b | 2376 | |
6274de49 MH |
2377 | /* Wait for disarming all kprobes by optimizer */ |
2378 | wait_for_kprobe_optimizer(); | |
bf8f6e5b AM |
2379 | } |
2380 | ||
2381 | /* | |
2382 | * XXX: The debugfs bool file interface doesn't allow for callbacks | |
2383 | * when the bool state is switched. We can reuse that facility when | |
2384 | * available | |
2385 | */ | |
2386 | static ssize_t read_enabled_file_bool(struct file *file, | |
2387 | char __user *user_buf, size_t count, loff_t *ppos) | |
2388 | { | |
2389 | char buf[3]; | |
2390 | ||
e579abeb | 2391 | if (!kprobes_all_disarmed) |
bf8f6e5b AM |
2392 | buf[0] = '1'; |
2393 | else | |
2394 | buf[0] = '0'; | |
2395 | buf[1] = '\n'; | |
2396 | buf[2] = 0x00; | |
2397 | return simple_read_from_buffer(user_buf, count, ppos, buf, 2); | |
2398 | } | |
2399 | ||
2400 | static ssize_t write_enabled_file_bool(struct file *file, | |
2401 | const char __user *user_buf, size_t count, loff_t *ppos) | |
2402 | { | |
2403 | char buf[32]; | |
efeb156e | 2404 | size_t buf_size; |
bf8f6e5b AM |
2405 | |
2406 | buf_size = min(count, (sizeof(buf)-1)); | |
2407 | if (copy_from_user(buf, user_buf, buf_size)) | |
2408 | return -EFAULT; | |
2409 | ||
10fb46d5 | 2410 | buf[buf_size] = '\0'; |
bf8f6e5b AM |
2411 | switch (buf[0]) { |
2412 | case 'y': | |
2413 | case 'Y': | |
2414 | case '1': | |
e579abeb | 2415 | arm_all_kprobes(); |
bf8f6e5b AM |
2416 | break; |
2417 | case 'n': | |
2418 | case 'N': | |
2419 | case '0': | |
e579abeb | 2420 | disarm_all_kprobes(); |
bf8f6e5b | 2421 | break; |
10fb46d5 MK |
2422 | default: |
2423 | return -EINVAL; | |
bf8f6e5b AM |
2424 | } |
2425 | ||
2426 | return count; | |
2427 | } | |
2428 | ||
828c0950 | 2429 | static const struct file_operations fops_kp = { |
bf8f6e5b AM |
2430 | .read = read_enabled_file_bool, |
2431 | .write = write_enabled_file_bool, | |
6038f373 | 2432 | .llseek = default_llseek, |
bf8f6e5b AM |
2433 | }; |
2434 | ||
55479f64 | 2435 | static int __init debugfs_kprobe_init(void) |
346fd59b SD |
2436 | { |
2437 | struct dentry *dir, *file; | |
bf8f6e5b | 2438 | unsigned int value = 1; |
346fd59b SD |
2439 | |
2440 | dir = debugfs_create_dir("kprobes", NULL); | |
2441 | if (!dir) | |
2442 | return -ENOMEM; | |
2443 | ||
e3869792 | 2444 | file = debugfs_create_file("list", 0444, dir, NULL, |
346fd59b | 2445 | &debugfs_kprobes_operations); |
63724740 MH |
2446 | if (!file) |
2447 | goto error; | |
346fd59b | 2448 | |
bf8f6e5b AM |
2449 | file = debugfs_create_file("enabled", 0600, dir, |
2450 | &value, &fops_kp); | |
63724740 MH |
2451 | if (!file) |
2452 | goto error; | |
2453 | ||
2454 | file = debugfs_create_file("blacklist", 0444, dir, NULL, | |
2455 | &debugfs_kprobe_blacklist_ops); | |
2456 | if (!file) | |
2457 | goto error; | |
bf8f6e5b | 2458 | |
346fd59b | 2459 | return 0; |
63724740 MH |
2460 | |
2461 | error: | |
2462 | debugfs_remove(dir); | |
2463 | return -ENOMEM; | |
346fd59b SD |
2464 | } |
2465 | ||
2466 | late_initcall(debugfs_kprobe_init); | |
2467 | #endif /* CONFIG_DEBUG_FS */ | |
2468 | ||
2469 | module_init(init_kprobes); | |
1da177e4 | 2470 | |
99081ab5 | 2471 | /* defined in arch/.../kernel/kprobes.c */ |
1da177e4 | 2472 | EXPORT_SYMBOL_GPL(jprobe_return); |