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1a59d1b8 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1da177e4 LT |
2 | /* |
3 | * Kernel Probes (KProbes) | |
4 | * kernel/kprobes.c | |
5 | * | |
1da177e4 LT |
6 | * Copyright (C) IBM Corporation, 2002, 2004 |
7 | * | |
8 | * 2002-Oct Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel | |
9 | * Probes initial implementation (includes suggestions from | |
10 | * Rusty Russell). | |
11 | * 2004-Aug Updated by Prasanna S Panchamukhi <prasanna@in.ibm.com> with | |
12 | * hlists and exceptions notifier as suggested by Andi Kleen. | |
13 | * 2004-July Suparna Bhattacharya <suparna@in.ibm.com> added jumper probes | |
14 | * interface to access function arguments. | |
15 | * 2004-Sep Prasanna S Panchamukhi <prasanna@in.ibm.com> Changed Kprobes | |
16 | * exceptions notifier to be first on the priority list. | |
b94cce92 HN |
17 | * 2005-May Hien Nguyen <hien@us.ibm.com>, Jim Keniston |
18 | * <jkenisto@us.ibm.com> and Prasanna S Panchamukhi | |
19 | * <prasanna@in.ibm.com> added function-return probes. | |
1da177e4 LT |
20 | */ |
21 | #include <linux/kprobes.h> | |
1da177e4 LT |
22 | #include <linux/hash.h> |
23 | #include <linux/init.h> | |
4e57b681 | 24 | #include <linux/slab.h> |
e3869792 | 25 | #include <linux/stddef.h> |
9984de1a | 26 | #include <linux/export.h> |
9ec4b1f3 | 27 | #include <linux/moduleloader.h> |
3a872d89 | 28 | #include <linux/kallsyms.h> |
b4c6c34a | 29 | #include <linux/freezer.h> |
346fd59b SD |
30 | #include <linux/seq_file.h> |
31 | #include <linux/debugfs.h> | |
b2be84df | 32 | #include <linux/sysctl.h> |
1eeb66a1 | 33 | #include <linux/kdebug.h> |
4460fdad | 34 | #include <linux/memory.h> |
4554dbcb | 35 | #include <linux/ftrace.h> |
afd66255 | 36 | #include <linux/cpu.h> |
bf5438fc | 37 | #include <linux/jump_label.h> |
69e49088 | 38 | #include <linux/perf_event.h> |
6333e8f7 | 39 | #include <linux/static_call.h> |
bf8f6e5b | 40 | |
bfd45be0 | 41 | #include <asm/sections.h> |
1da177e4 LT |
42 | #include <asm/cacheflush.h> |
43 | #include <asm/errno.h> | |
7c0f6ba6 | 44 | #include <linux/uaccess.h> |
1da177e4 LT |
45 | |
46 | #define KPROBE_HASH_BITS 6 | |
47 | #define KPROBE_TABLE_SIZE (1 << KPROBE_HASH_BITS) | |
48 | ||
3a872d89 | 49 | |
ef53d9c5 | 50 | static int kprobes_initialized; |
7e6a71d8 MH |
51 | /* kprobe_table can be accessed by |
52 | * - Normal hlist traversal and RCU add/del under kprobe_mutex is held. | |
53 | * Or | |
54 | * - RCU hlist traversal under disabling preempt (breakpoint handlers) | |
55 | */ | |
1da177e4 | 56 | static struct hlist_head kprobe_table[KPROBE_TABLE_SIZE]; |
b94cce92 | 57 | static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE]; |
1da177e4 | 58 | |
bf8f6e5b | 59 | /* NOTE: change this value only with kprobe_mutex held */ |
e579abeb | 60 | static bool kprobes_all_disarmed; |
bf8f6e5b | 61 | |
43948f50 MH |
62 | /* This protects kprobe_table and optimizing_list */ |
63 | static DEFINE_MUTEX(kprobe_mutex); | |
e6584523 | 64 | static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL; |
ef53d9c5 | 65 | static struct { |
ec484608 | 66 | raw_spinlock_t lock ____cacheline_aligned_in_smp; |
ef53d9c5 S |
67 | } kretprobe_table_locks[KPROBE_TABLE_SIZE]; |
68 | ||
290e3070 NR |
69 | kprobe_opcode_t * __weak kprobe_lookup_name(const char *name, |
70 | unsigned int __unused) | |
49e0b465 NR |
71 | { |
72 | return ((kprobe_opcode_t *)(kallsyms_lookup_name(name))); | |
73 | } | |
74 | ||
ec484608 | 75 | static raw_spinlock_t *kretprobe_table_lock_ptr(unsigned long hash) |
ef53d9c5 S |
76 | { |
77 | return &(kretprobe_table_locks[hash].lock); | |
78 | } | |
1da177e4 | 79 | |
376e2424 MH |
80 | /* Blacklist -- list of struct kprobe_blacklist_entry */ |
81 | static LIST_HEAD(kprobe_blacklist); | |
3d8d996e | 82 | |
2d14e39d | 83 | #ifdef __ARCH_WANT_KPROBES_INSN_SLOT |
9ec4b1f3 AM |
84 | /* |
85 | * kprobe->ainsn.insn points to the copy of the instruction to be | |
86 | * single-stepped. x86_64, POWER4 and above have no-exec support and | |
87 | * stepping on the instruction on a vmalloced/kmalloced/data page | |
88 | * is a recipe for disaster | |
89 | */ | |
9ec4b1f3 | 90 | struct kprobe_insn_page { |
c5cb5a2d | 91 | struct list_head list; |
9ec4b1f3 | 92 | kprobe_opcode_t *insns; /* Page of instruction slots */ |
af96397d | 93 | struct kprobe_insn_cache *cache; |
9ec4b1f3 | 94 | int nused; |
b4c6c34a | 95 | int ngarbage; |
4610ee1d | 96 | char slot_used[]; |
9ec4b1f3 AM |
97 | }; |
98 | ||
4610ee1d MH |
99 | #define KPROBE_INSN_PAGE_SIZE(slots) \ |
100 | (offsetof(struct kprobe_insn_page, slot_used) + \ | |
101 | (sizeof(char) * (slots))) | |
102 | ||
4610ee1d MH |
103 | static int slots_per_page(struct kprobe_insn_cache *c) |
104 | { | |
105 | return PAGE_SIZE/(c->insn_size * sizeof(kprobe_opcode_t)); | |
106 | } | |
107 | ||
ab40c5c6 MH |
108 | enum kprobe_slot_state { |
109 | SLOT_CLEAN = 0, | |
110 | SLOT_DIRTY = 1, | |
111 | SLOT_USED = 2, | |
112 | }; | |
113 | ||
63fef14f | 114 | void __weak *alloc_insn_page(void) |
af96397d HC |
115 | { |
116 | return module_alloc(PAGE_SIZE); | |
117 | } | |
118 | ||
c93f5cf5 | 119 | void __weak free_insn_page(void *page) |
af96397d | 120 | { |
be1f221c | 121 | module_memfree(page); |
af96397d HC |
122 | } |
123 | ||
c802d64a HC |
124 | struct kprobe_insn_cache kprobe_insn_slots = { |
125 | .mutex = __MUTEX_INITIALIZER(kprobe_insn_slots.mutex), | |
af96397d HC |
126 | .alloc = alloc_insn_page, |
127 | .free = free_insn_page, | |
d002b8bc | 128 | .sym = KPROBE_INSN_PAGE_SYM, |
4610ee1d MH |
129 | .pages = LIST_HEAD_INIT(kprobe_insn_slots.pages), |
130 | .insn_size = MAX_INSN_SIZE, | |
131 | .nr_garbage = 0, | |
132 | }; | |
55479f64 | 133 | static int collect_garbage_slots(struct kprobe_insn_cache *c); |
b4c6c34a | 134 | |
9ec4b1f3 | 135 | /** |
12941560 | 136 | * __get_insn_slot() - Find a slot on an executable page for an instruction. |
9ec4b1f3 AM |
137 | * We allocate an executable page if there's no room on existing ones. |
138 | */ | |
55479f64 | 139 | kprobe_opcode_t *__get_insn_slot(struct kprobe_insn_cache *c) |
9ec4b1f3 AM |
140 | { |
141 | struct kprobe_insn_page *kip; | |
c802d64a | 142 | kprobe_opcode_t *slot = NULL; |
9ec4b1f3 | 143 | |
5b485629 | 144 | /* Since the slot array is not protected by rcu, we need a mutex */ |
c802d64a | 145 | mutex_lock(&c->mutex); |
6f716acd | 146 | retry: |
5b485629 MH |
147 | rcu_read_lock(); |
148 | list_for_each_entry_rcu(kip, &c->pages, list) { | |
4610ee1d | 149 | if (kip->nused < slots_per_page(c)) { |
9ec4b1f3 | 150 | int i; |
4610ee1d | 151 | for (i = 0; i < slots_per_page(c); i++) { |
ab40c5c6 MH |
152 | if (kip->slot_used[i] == SLOT_CLEAN) { |
153 | kip->slot_used[i] = SLOT_USED; | |
9ec4b1f3 | 154 | kip->nused++; |
c802d64a | 155 | slot = kip->insns + (i * c->insn_size); |
5b485629 | 156 | rcu_read_unlock(); |
c802d64a | 157 | goto out; |
9ec4b1f3 AM |
158 | } |
159 | } | |
4610ee1d MH |
160 | /* kip->nused is broken. Fix it. */ |
161 | kip->nused = slots_per_page(c); | |
162 | WARN_ON(1); | |
9ec4b1f3 AM |
163 | } |
164 | } | |
5b485629 | 165 | rcu_read_unlock(); |
9ec4b1f3 | 166 | |
b4c6c34a | 167 | /* If there are any garbage slots, collect it and try again. */ |
4610ee1d | 168 | if (c->nr_garbage && collect_garbage_slots(c) == 0) |
b4c6c34a | 169 | goto retry; |
4610ee1d MH |
170 | |
171 | /* All out of space. Need to allocate a new page. */ | |
172 | kip = kmalloc(KPROBE_INSN_PAGE_SIZE(slots_per_page(c)), GFP_KERNEL); | |
6f716acd | 173 | if (!kip) |
c802d64a | 174 | goto out; |
9ec4b1f3 AM |
175 | |
176 | /* | |
177 | * Use module_alloc so this page is within +/- 2GB of where the | |
178 | * kernel image and loaded module images reside. This is required | |
179 | * so x86_64 can correctly handle the %rip-relative fixups. | |
180 | */ | |
af96397d | 181 | kip->insns = c->alloc(); |
9ec4b1f3 AM |
182 | if (!kip->insns) { |
183 | kfree(kip); | |
c802d64a | 184 | goto out; |
9ec4b1f3 | 185 | } |
c5cb5a2d | 186 | INIT_LIST_HEAD(&kip->list); |
4610ee1d | 187 | memset(kip->slot_used, SLOT_CLEAN, slots_per_page(c)); |
ab40c5c6 | 188 | kip->slot_used[0] = SLOT_USED; |
9ec4b1f3 | 189 | kip->nused = 1; |
b4c6c34a | 190 | kip->ngarbage = 0; |
af96397d | 191 | kip->cache = c; |
5b485629 | 192 | list_add_rcu(&kip->list, &c->pages); |
c802d64a | 193 | slot = kip->insns; |
69e49088 AH |
194 | |
195 | /* Record the perf ksymbol register event after adding the page */ | |
196 | perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL, (unsigned long)kip->insns, | |
197 | PAGE_SIZE, false, c->sym); | |
c802d64a HC |
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)) { |
69e49088 AH |
216 | /* |
217 | * Record perf ksymbol unregister event before removing | |
218 | * the page. | |
219 | */ | |
220 | perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL, | |
221 | (unsigned long)kip->insns, PAGE_SIZE, true, | |
222 | kip->cache->sym); | |
5b485629 MH |
223 | list_del_rcu(&kip->list); |
224 | synchronize_rcu(); | |
af96397d | 225 | kip->cache->free(kip->insns); |
b4c6c34a MH |
226 | kfree(kip); |
227 | } | |
228 | return 1; | |
229 | } | |
230 | return 0; | |
231 | } | |
232 | ||
55479f64 | 233 | static int collect_garbage_slots(struct kprobe_insn_cache *c) |
b4c6c34a | 234 | { |
c5cb5a2d | 235 | struct kprobe_insn_page *kip, *next; |
b4c6c34a | 236 | |
615d0ebb | 237 | /* Ensure no-one is interrupted on the garbages */ |
ae8b7ce7 | 238 | synchronize_rcu(); |
b4c6c34a | 239 | |
4610ee1d | 240 | list_for_each_entry_safe(kip, next, &c->pages, list) { |
b4c6c34a | 241 | int i; |
b4c6c34a MH |
242 | if (kip->ngarbage == 0) |
243 | continue; | |
244 | kip->ngarbage = 0; /* we will collect all garbages */ | |
4610ee1d | 245 | for (i = 0; i < slots_per_page(c); i++) { |
5b485629 | 246 | if (kip->slot_used[i] == SLOT_DIRTY && collect_one_slot(kip, i)) |
b4c6c34a MH |
247 | break; |
248 | } | |
249 | } | |
4610ee1d | 250 | c->nr_garbage = 0; |
b4c6c34a MH |
251 | return 0; |
252 | } | |
253 | ||
55479f64 MH |
254 | void __free_insn_slot(struct kprobe_insn_cache *c, |
255 | kprobe_opcode_t *slot, int dirty) | |
9ec4b1f3 AM |
256 | { |
257 | struct kprobe_insn_page *kip; | |
5b485629 | 258 | long idx; |
9ec4b1f3 | 259 | |
c802d64a | 260 | mutex_lock(&c->mutex); |
5b485629 MH |
261 | rcu_read_lock(); |
262 | list_for_each_entry_rcu(kip, &c->pages, list) { | |
263 | idx = ((long)slot - (long)kip->insns) / | |
264 | (c->insn_size * sizeof(kprobe_opcode_t)); | |
265 | if (idx >= 0 && idx < slots_per_page(c)) | |
c802d64a | 266 | goto out; |
9ec4b1f3 | 267 | } |
5b485629 | 268 | /* Could not find this slot. */ |
4610ee1d | 269 | WARN_ON(1); |
5b485629 | 270 | kip = NULL; |
c802d64a | 271 | out: |
5b485629 MH |
272 | rcu_read_unlock(); |
273 | /* Mark and sweep: this may sleep */ | |
274 | if (kip) { | |
275 | /* Check double free */ | |
276 | WARN_ON(kip->slot_used[idx] != SLOT_USED); | |
277 | if (dirty) { | |
278 | kip->slot_used[idx] = SLOT_DIRTY; | |
279 | kip->ngarbage++; | |
280 | if (++c->nr_garbage > slots_per_page(c)) | |
281 | collect_garbage_slots(c); | |
282 | } else { | |
283 | collect_one_slot(kip, idx); | |
284 | } | |
285 | } | |
c802d64a | 286 | mutex_unlock(&c->mutex); |
4610ee1d | 287 | } |
6f716acd | 288 | |
5b485629 MH |
289 | /* |
290 | * Check given address is on the page of kprobe instruction slots. | |
291 | * This will be used for checking whether the address on a stack | |
292 | * is on a text area or not. | |
293 | */ | |
294 | bool __is_insn_slot_addr(struct kprobe_insn_cache *c, unsigned long addr) | |
295 | { | |
296 | struct kprobe_insn_page *kip; | |
297 | bool ret = false; | |
298 | ||
299 | rcu_read_lock(); | |
300 | list_for_each_entry_rcu(kip, &c->pages, list) { | |
301 | if (addr >= (unsigned long)kip->insns && | |
302 | addr < (unsigned long)kip->insns + PAGE_SIZE) { | |
303 | ret = true; | |
304 | break; | |
305 | } | |
306 | } | |
307 | rcu_read_unlock(); | |
308 | ||
309 | return ret; | |
310 | } | |
311 | ||
d002b8bc AH |
312 | int kprobe_cache_get_kallsym(struct kprobe_insn_cache *c, unsigned int *symnum, |
313 | unsigned long *value, char *type, char *sym) | |
314 | { | |
315 | struct kprobe_insn_page *kip; | |
316 | int ret = -ERANGE; | |
317 | ||
318 | rcu_read_lock(); | |
319 | list_for_each_entry_rcu(kip, &c->pages, list) { | |
320 | if ((*symnum)--) | |
321 | continue; | |
322 | strlcpy(sym, c->sym, KSYM_NAME_LEN); | |
323 | *type = 't'; | |
324 | *value = (unsigned long)kip->insns; | |
325 | ret = 0; | |
326 | break; | |
327 | } | |
328 | rcu_read_unlock(); | |
329 | ||
330 | return ret; | |
331 | } | |
332 | ||
afd66255 MH |
333 | #ifdef CONFIG_OPTPROBES |
334 | /* For optimized_kprobe buffer */ | |
c802d64a HC |
335 | struct kprobe_insn_cache kprobe_optinsn_slots = { |
336 | .mutex = __MUTEX_INITIALIZER(kprobe_optinsn_slots.mutex), | |
af96397d HC |
337 | .alloc = alloc_insn_page, |
338 | .free = free_insn_page, | |
d002b8bc | 339 | .sym = KPROBE_OPTINSN_PAGE_SYM, |
afd66255 MH |
340 | .pages = LIST_HEAD_INIT(kprobe_optinsn_slots.pages), |
341 | /* .insn_size is initialized later */ | |
342 | .nr_garbage = 0, | |
343 | }; | |
afd66255 | 344 | #endif |
2d14e39d | 345 | #endif |
9ec4b1f3 | 346 | |
e6584523 AM |
347 | /* We have preemption disabled.. so it is safe to use __ versions */ |
348 | static inline void set_kprobe_instance(struct kprobe *kp) | |
349 | { | |
b76834bc | 350 | __this_cpu_write(kprobe_instance, kp); |
e6584523 AM |
351 | } |
352 | ||
353 | static inline void reset_kprobe_instance(void) | |
354 | { | |
b76834bc | 355 | __this_cpu_write(kprobe_instance, NULL); |
e6584523 AM |
356 | } |
357 | ||
3516a460 AM |
358 | /* |
359 | * This routine is called either: | |
49a2a1b8 | 360 | * - under the kprobe_mutex - during kprobe_[un]register() |
3516a460 | 361 | * OR |
d217d545 | 362 | * - with preemption disabled - from arch/xxx/kernel/kprobes.c |
3516a460 | 363 | */ |
820aede0 | 364 | struct kprobe *get_kprobe(void *addr) |
1da177e4 LT |
365 | { |
366 | struct hlist_head *head; | |
3516a460 | 367 | struct kprobe *p; |
1da177e4 LT |
368 | |
369 | head = &kprobe_table[hash_ptr(addr, KPROBE_HASH_BITS)]; | |
6743ad43 MH |
370 | hlist_for_each_entry_rcu(p, head, hlist, |
371 | lockdep_is_held(&kprobe_mutex)) { | |
1da177e4 LT |
372 | if (p->addr == addr) |
373 | return p; | |
374 | } | |
afd66255 | 375 | |
1da177e4 LT |
376 | return NULL; |
377 | } | |
820aede0 | 378 | NOKPROBE_SYMBOL(get_kprobe); |
1da177e4 | 379 | |
820aede0 | 380 | static int aggr_pre_handler(struct kprobe *p, struct pt_regs *regs); |
afd66255 MH |
381 | |
382 | /* Return true if the kprobe is an aggregator */ | |
383 | static inline int kprobe_aggrprobe(struct kprobe *p) | |
384 | { | |
385 | return p->pre_handler == aggr_pre_handler; | |
386 | } | |
387 | ||
6274de49 MH |
388 | /* Return true(!0) if the kprobe is unused */ |
389 | static inline int kprobe_unused(struct kprobe *p) | |
390 | { | |
391 | return kprobe_aggrprobe(p) && kprobe_disabled(p) && | |
392 | list_empty(&p->list); | |
393 | } | |
394 | ||
afd66255 MH |
395 | /* |
396 | * Keep all fields in the kprobe consistent | |
397 | */ | |
6d8e40a8 | 398 | static inline void copy_kprobe(struct kprobe *ap, struct kprobe *p) |
afd66255 | 399 | { |
6d8e40a8 MH |
400 | memcpy(&p->opcode, &ap->opcode, sizeof(kprobe_opcode_t)); |
401 | memcpy(&p->ainsn, &ap->ainsn, sizeof(struct arch_specific_insn)); | |
afd66255 MH |
402 | } |
403 | ||
404 | #ifdef CONFIG_OPTPROBES | |
b2be84df MH |
405 | /* NOTE: change this value only with kprobe_mutex held */ |
406 | static bool kprobes_allow_optimization; | |
407 | ||
afd66255 MH |
408 | /* |
409 | * Call all pre_handler on the list, but ignores its return value. | |
410 | * This must be called from arch-dep optimized caller. | |
411 | */ | |
820aede0 | 412 | void opt_pre_handler(struct kprobe *p, struct pt_regs *regs) |
afd66255 MH |
413 | { |
414 | struct kprobe *kp; | |
415 | ||
416 | list_for_each_entry_rcu(kp, &p->list, list) { | |
417 | if (kp->pre_handler && likely(!kprobe_disabled(kp))) { | |
418 | set_kprobe_instance(kp); | |
4f3a8714 | 419 | kp->pre_handler(kp, regs); |
afd66255 MH |
420 | } |
421 | reset_kprobe_instance(); | |
422 | } | |
423 | } | |
820aede0 | 424 | NOKPROBE_SYMBOL(opt_pre_handler); |
afd66255 | 425 | |
6274de49 | 426 | /* Free optimized instructions and optimized_kprobe */ |
55479f64 | 427 | static void free_aggr_kprobe(struct kprobe *p) |
6274de49 MH |
428 | { |
429 | struct optimized_kprobe *op; | |
430 | ||
431 | op = container_of(p, struct optimized_kprobe, kp); | |
432 | arch_remove_optimized_kprobe(op); | |
433 | arch_remove_kprobe(p); | |
434 | kfree(op); | |
435 | } | |
436 | ||
afd66255 MH |
437 | /* Return true(!0) if the kprobe is ready for optimization. */ |
438 | static inline int kprobe_optready(struct kprobe *p) | |
439 | { | |
440 | struct optimized_kprobe *op; | |
441 | ||
442 | if (kprobe_aggrprobe(p)) { | |
443 | op = container_of(p, struct optimized_kprobe, kp); | |
444 | return arch_prepared_optinsn(&op->optinsn); | |
445 | } | |
446 | ||
447 | return 0; | |
448 | } | |
449 | ||
6274de49 MH |
450 | /* Return true(!0) if the kprobe is disarmed. Note: p must be on hash list */ |
451 | static inline int kprobe_disarmed(struct kprobe *p) | |
452 | { | |
453 | struct optimized_kprobe *op; | |
454 | ||
455 | /* If kprobe is not aggr/opt probe, just return kprobe is disabled */ | |
456 | if (!kprobe_aggrprobe(p)) | |
457 | return kprobe_disabled(p); | |
458 | ||
459 | op = container_of(p, struct optimized_kprobe, kp); | |
460 | ||
461 | return kprobe_disabled(p) && list_empty(&op->list); | |
462 | } | |
463 | ||
464 | /* Return true(!0) if the probe is queued on (un)optimizing lists */ | |
55479f64 | 465 | static int kprobe_queued(struct kprobe *p) |
6274de49 MH |
466 | { |
467 | struct optimized_kprobe *op; | |
468 | ||
469 | if (kprobe_aggrprobe(p)) { | |
470 | op = container_of(p, struct optimized_kprobe, kp); | |
471 | if (!list_empty(&op->list)) | |
472 | return 1; | |
473 | } | |
474 | return 0; | |
475 | } | |
476 | ||
afd66255 MH |
477 | /* |
478 | * Return an optimized kprobe whose optimizing code replaces | |
479 | * instructions including addr (exclude breakpoint). | |
480 | */ | |
55479f64 | 481 | static struct kprobe *get_optimized_kprobe(unsigned long addr) |
afd66255 MH |
482 | { |
483 | int i; | |
484 | struct kprobe *p = NULL; | |
485 | struct optimized_kprobe *op; | |
486 | ||
487 | /* Don't check i == 0, since that is a breakpoint case. */ | |
488 | for (i = 1; !p && i < MAX_OPTIMIZED_LENGTH; i++) | |
489 | p = get_kprobe((void *)(addr - i)); | |
490 | ||
491 | if (p && kprobe_optready(p)) { | |
492 | op = container_of(p, struct optimized_kprobe, kp); | |
493 | if (arch_within_optimized_kprobe(op, addr)) | |
494 | return p; | |
495 | } | |
496 | ||
497 | return NULL; | |
498 | } | |
499 | ||
500 | /* Optimization staging list, protected by kprobe_mutex */ | |
501 | static LIST_HEAD(optimizing_list); | |
6274de49 | 502 | static LIST_HEAD(unoptimizing_list); |
7b959fc5 | 503 | static LIST_HEAD(freeing_list); |
afd66255 MH |
504 | |
505 | static void kprobe_optimizer(struct work_struct *work); | |
506 | static DECLARE_DELAYED_WORK(optimizing_work, kprobe_optimizer); | |
507 | #define OPTIMIZE_DELAY 5 | |
508 | ||
61f4e13f MH |
509 | /* |
510 | * Optimize (replace a breakpoint with a jump) kprobes listed on | |
511 | * optimizing_list. | |
512 | */ | |
55479f64 | 513 | static void do_optimize_kprobes(void) |
afd66255 | 514 | { |
f1c6ece2 | 515 | lockdep_assert_held(&text_mutex); |
afd66255 MH |
516 | /* |
517 | * The optimization/unoptimization refers online_cpus via | |
518 | * stop_machine() and cpu-hotplug modifies online_cpus. | |
519 | * And same time, text_mutex will be held in cpu-hotplug and here. | |
520 | * This combination can cause a deadlock (cpu-hotplug try to lock | |
521 | * text_mutex but stop_machine can not be done because online_cpus | |
522 | * has been changed) | |
2d1e38f5 | 523 | * To avoid this deadlock, caller must have locked cpu hotplug |
afd66255 MH |
524 | * for preventing cpu-hotplug outside of text_mutex locking. |
525 | */ | |
2d1e38f5 TG |
526 | lockdep_assert_cpus_held(); |
527 | ||
528 | /* Optimization never be done when disarmed */ | |
529 | if (kprobes_all_disarmed || !kprobes_allow_optimization || | |
530 | list_empty(&optimizing_list)) | |
531 | return; | |
532 | ||
cd7ebe22 | 533 | arch_optimize_kprobes(&optimizing_list); |
61f4e13f MH |
534 | } |
535 | ||
6274de49 MH |
536 | /* |
537 | * Unoptimize (replace a jump with a breakpoint and remove the breakpoint | |
538 | * if need) kprobes listed on unoptimizing_list. | |
539 | */ | |
55479f64 | 540 | static void do_unoptimize_kprobes(void) |
6274de49 MH |
541 | { |
542 | struct optimized_kprobe *op, *tmp; | |
543 | ||
f1c6ece2 | 544 | lockdep_assert_held(&text_mutex); |
2d1e38f5 TG |
545 | /* See comment in do_optimize_kprobes() */ |
546 | lockdep_assert_cpus_held(); | |
547 | ||
6274de49 MH |
548 | /* Unoptimization must be done anytime */ |
549 | if (list_empty(&unoptimizing_list)) | |
550 | return; | |
551 | ||
7b959fc5 | 552 | arch_unoptimize_kprobes(&unoptimizing_list, &freeing_list); |
f984ba4e | 553 | /* Loop free_list for disarming */ |
7b959fc5 | 554 | list_for_each_entry_safe(op, tmp, &freeing_list, list) { |
f66c0447 MH |
555 | /* Switching from detour code to origin */ |
556 | op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED; | |
6274de49 MH |
557 | /* Disarm probes if marked disabled */ |
558 | if (kprobe_disabled(&op->kp)) | |
559 | arch_disarm_kprobe(&op->kp); | |
560 | if (kprobe_unused(&op->kp)) { | |
561 | /* | |
562 | * Remove unused probes from hash list. After waiting | |
563 | * for synchronization, these probes are reclaimed. | |
564 | * (reclaiming is done by do_free_cleaned_kprobes.) | |
565 | */ | |
566 | hlist_del_rcu(&op->kp.hlist); | |
6274de49 MH |
567 | } else |
568 | list_del_init(&op->list); | |
569 | } | |
6274de49 MH |
570 | } |
571 | ||
572 | /* Reclaim all kprobes on the free_list */ | |
55479f64 | 573 | static void do_free_cleaned_kprobes(void) |
6274de49 MH |
574 | { |
575 | struct optimized_kprobe *op, *tmp; | |
576 | ||
7b959fc5 | 577 | list_for_each_entry_safe(op, tmp, &freeing_list, list) { |
6274de49 | 578 | list_del_init(&op->list); |
cbdd96f5 MH |
579 | if (WARN_ON_ONCE(!kprobe_unused(&op->kp))) { |
580 | /* | |
581 | * This must not happen, but if there is a kprobe | |
582 | * still in use, keep it on kprobes hash list. | |
583 | */ | |
584 | continue; | |
585 | } | |
6274de49 MH |
586 | free_aggr_kprobe(&op->kp); |
587 | } | |
588 | } | |
589 | ||
590 | /* Start optimizer after OPTIMIZE_DELAY passed */ | |
55479f64 | 591 | static void kick_kprobe_optimizer(void) |
6274de49 | 592 | { |
ad72b3be | 593 | schedule_delayed_work(&optimizing_work, OPTIMIZE_DELAY); |
6274de49 MH |
594 | } |
595 | ||
61f4e13f | 596 | /* Kprobe jump optimizer */ |
55479f64 | 597 | static void kprobe_optimizer(struct work_struct *work) |
61f4e13f | 598 | { |
72ef3794 | 599 | mutex_lock(&kprobe_mutex); |
2d1e38f5 | 600 | cpus_read_lock(); |
f1c6ece2 | 601 | mutex_lock(&text_mutex); |
61f4e13f MH |
602 | |
603 | /* | |
6274de49 MH |
604 | * Step 1: Unoptimize kprobes and collect cleaned (unused and disarmed) |
605 | * kprobes before waiting for quiesence period. | |
606 | */ | |
7b959fc5 | 607 | do_unoptimize_kprobes(); |
6274de49 MH |
608 | |
609 | /* | |
a30b85df MH |
610 | * Step 2: Wait for quiesence period to ensure all potentially |
611 | * preempted tasks to have normally scheduled. Because optprobe | |
612 | * may modify multiple instructions, there is a chance that Nth | |
613 | * instruction is preempted. In that case, such tasks can return | |
614 | * to 2nd-Nth byte of jump instruction. This wait is for avoiding it. | |
615 | * Note that on non-preemptive kernel, this is transparently converted | |
616 | * to synchronoze_sched() to wait for all interrupts to have completed. | |
61f4e13f | 617 | */ |
a30b85df | 618 | synchronize_rcu_tasks(); |
61f4e13f | 619 | |
6274de49 | 620 | /* Step 3: Optimize kprobes after quiesence period */ |
61f4e13f | 621 | do_optimize_kprobes(); |
6274de49 MH |
622 | |
623 | /* Step 4: Free cleaned kprobes after quiesence period */ | |
7b959fc5 | 624 | do_free_cleaned_kprobes(); |
6274de49 | 625 | |
f1c6ece2 | 626 | mutex_unlock(&text_mutex); |
2d1e38f5 | 627 | cpus_read_unlock(); |
6274de49 | 628 | |
cd7ebe22 | 629 | /* Step 5: Kick optimizer again if needed */ |
f984ba4e | 630 | if (!list_empty(&optimizing_list) || !list_empty(&unoptimizing_list)) |
cd7ebe22 | 631 | kick_kprobe_optimizer(); |
1a0aa991 MH |
632 | |
633 | mutex_unlock(&kprobe_mutex); | |
6274de49 MH |
634 | } |
635 | ||
636 | /* Wait for completing optimization and unoptimization */ | |
30e7d894 | 637 | void wait_for_kprobe_optimizer(void) |
6274de49 | 638 | { |
ad72b3be TH |
639 | mutex_lock(&kprobe_mutex); |
640 | ||
641 | while (!list_empty(&optimizing_list) || !list_empty(&unoptimizing_list)) { | |
642 | mutex_unlock(&kprobe_mutex); | |
643 | ||
644 | /* this will also make optimizing_work execute immmediately */ | |
645 | flush_delayed_work(&optimizing_work); | |
646 | /* @optimizing_work might not have been queued yet, relax */ | |
647 | cpu_relax(); | |
648 | ||
649 | mutex_lock(&kprobe_mutex); | |
650 | } | |
651 | ||
652 | mutex_unlock(&kprobe_mutex); | |
afd66255 MH |
653 | } |
654 | ||
e4add247 MH |
655 | static bool optprobe_queued_unopt(struct optimized_kprobe *op) |
656 | { | |
657 | struct optimized_kprobe *_op; | |
658 | ||
659 | list_for_each_entry(_op, &unoptimizing_list, list) { | |
660 | if (op == _op) | |
661 | return true; | |
662 | } | |
663 | ||
664 | return false; | |
665 | } | |
666 | ||
afd66255 | 667 | /* Optimize kprobe if p is ready to be optimized */ |
55479f64 | 668 | static void optimize_kprobe(struct kprobe *p) |
afd66255 MH |
669 | { |
670 | struct optimized_kprobe *op; | |
671 | ||
672 | /* Check if the kprobe is disabled or not ready for optimization. */ | |
b2be84df | 673 | if (!kprobe_optready(p) || !kprobes_allow_optimization || |
afd66255 MH |
674 | (kprobe_disabled(p) || kprobes_all_disarmed)) |
675 | return; | |
676 | ||
059053a2 MH |
677 | /* kprobes with post_handler can not be optimized */ |
678 | if (p->post_handler) | |
afd66255 MH |
679 | return; |
680 | ||
681 | op = container_of(p, struct optimized_kprobe, kp); | |
682 | ||
683 | /* Check there is no other kprobes at the optimized instructions */ | |
684 | if (arch_check_optimized_kprobe(op) < 0) | |
685 | return; | |
686 | ||
687 | /* Check if it is already optimized. */ | |
e4add247 MH |
688 | if (op->kp.flags & KPROBE_FLAG_OPTIMIZED) { |
689 | if (optprobe_queued_unopt(op)) { | |
690 | /* This is under unoptimizing. Just dequeue the probe */ | |
691 | list_del_init(&op->list); | |
692 | } | |
afd66255 | 693 | return; |
e4add247 | 694 | } |
afd66255 | 695 | op->kp.flags |= KPROBE_FLAG_OPTIMIZED; |
6274de49 | 696 | |
e4add247 MH |
697 | /* On unoptimizing/optimizing_list, op must have OPTIMIZED flag */ |
698 | if (WARN_ON_ONCE(!list_empty(&op->list))) | |
699 | return; | |
700 | ||
701 | list_add(&op->list, &optimizing_list); | |
702 | kick_kprobe_optimizer(); | |
6274de49 MH |
703 | } |
704 | ||
705 | /* Short cut to direct unoptimizing */ | |
55479f64 | 706 | static void force_unoptimize_kprobe(struct optimized_kprobe *op) |
6274de49 | 707 | { |
2d1e38f5 | 708 | lockdep_assert_cpus_held(); |
6274de49 | 709 | arch_unoptimize_kprobe(op); |
f66c0447 | 710 | op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED; |
afd66255 MH |
711 | } |
712 | ||
713 | /* Unoptimize a kprobe if p is optimized */ | |
55479f64 | 714 | static void unoptimize_kprobe(struct kprobe *p, bool force) |
afd66255 MH |
715 | { |
716 | struct optimized_kprobe *op; | |
717 | ||
6274de49 MH |
718 | if (!kprobe_aggrprobe(p) || kprobe_disarmed(p)) |
719 | return; /* This is not an optprobe nor optimized */ | |
720 | ||
721 | op = container_of(p, struct optimized_kprobe, kp); | |
e4add247 | 722 | if (!kprobe_optimized(p)) |
6274de49 | 723 | return; |
6274de49 | 724 | |
6274de49 | 725 | if (!list_empty(&op->list)) { |
e4add247 MH |
726 | if (optprobe_queued_unopt(op)) { |
727 | /* Queued in unoptimizing queue */ | |
728 | if (force) { | |
729 | /* | |
730 | * Forcibly unoptimize the kprobe here, and queue it | |
731 | * in the freeing list for release afterwards. | |
732 | */ | |
733 | force_unoptimize_kprobe(op); | |
734 | list_move(&op->list, &freeing_list); | |
735 | } | |
736 | } else { | |
737 | /* Dequeue from the optimizing queue */ | |
738 | list_del_init(&op->list); | |
739 | op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED; | |
740 | } | |
6274de49 MH |
741 | return; |
742 | } | |
e4add247 | 743 | |
6274de49 | 744 | /* Optimized kprobe case */ |
e4add247 | 745 | if (force) { |
6274de49 MH |
746 | /* Forcibly update the code: this is a special case */ |
747 | force_unoptimize_kprobe(op); | |
e4add247 | 748 | } else { |
6274de49 MH |
749 | list_add(&op->list, &unoptimizing_list); |
750 | kick_kprobe_optimizer(); | |
afd66255 MH |
751 | } |
752 | } | |
753 | ||
0490cd1f | 754 | /* Cancel unoptimizing for reusing */ |
819319fc | 755 | static int reuse_unused_kprobe(struct kprobe *ap) |
0490cd1f MH |
756 | { |
757 | struct optimized_kprobe *op; | |
758 | ||
0490cd1f MH |
759 | /* |
760 | * Unused kprobe MUST be on the way of delayed unoptimizing (means | |
761 | * there is still a relative jump) and disabled. | |
762 | */ | |
763 | op = container_of(ap, struct optimized_kprobe, kp); | |
4458515b | 764 | WARN_ON_ONCE(list_empty(&op->list)); |
0490cd1f MH |
765 | /* Enable the probe again */ |
766 | ap->flags &= ~KPROBE_FLAG_DISABLED; | |
767 | /* Optimize it again (remove from op->list) */ | |
5f843ed4 MH |
768 | if (!kprobe_optready(ap)) |
769 | return -EINVAL; | |
819319fc | 770 | |
0490cd1f | 771 | optimize_kprobe(ap); |
819319fc | 772 | return 0; |
0490cd1f MH |
773 | } |
774 | ||
afd66255 | 775 | /* Remove optimized instructions */ |
55479f64 | 776 | static void kill_optimized_kprobe(struct kprobe *p) |
afd66255 MH |
777 | { |
778 | struct optimized_kprobe *op; | |
779 | ||
780 | op = container_of(p, struct optimized_kprobe, kp); | |
6274de49 MH |
781 | if (!list_empty(&op->list)) |
782 | /* Dequeue from the (un)optimization queue */ | |
afd66255 | 783 | list_del_init(&op->list); |
6274de49 | 784 | op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED; |
7b959fc5 MH |
785 | |
786 | if (kprobe_unused(p)) { | |
787 | /* Enqueue if it is unused */ | |
788 | list_add(&op->list, &freeing_list); | |
789 | /* | |
790 | * Remove unused probes from the hash list. After waiting | |
791 | * for synchronization, this probe is reclaimed. | |
792 | * (reclaiming is done by do_free_cleaned_kprobes().) | |
793 | */ | |
794 | hlist_del_rcu(&op->kp.hlist); | |
795 | } | |
796 | ||
6274de49 | 797 | /* Don't touch the code, because it is already freed. */ |
afd66255 MH |
798 | arch_remove_optimized_kprobe(op); |
799 | } | |
800 | ||
a460246c MH |
801 | static inline |
802 | void __prepare_optimized_kprobe(struct optimized_kprobe *op, struct kprobe *p) | |
803 | { | |
804 | if (!kprobe_ftrace(p)) | |
805 | arch_prepare_optimized_kprobe(op, p); | |
806 | } | |
807 | ||
afd66255 | 808 | /* Try to prepare optimized instructions */ |
55479f64 | 809 | static void prepare_optimized_kprobe(struct kprobe *p) |
afd66255 MH |
810 | { |
811 | struct optimized_kprobe *op; | |
812 | ||
813 | op = container_of(p, struct optimized_kprobe, kp); | |
a460246c | 814 | __prepare_optimized_kprobe(op, p); |
afd66255 MH |
815 | } |
816 | ||
afd66255 | 817 | /* Allocate new optimized_kprobe and try to prepare optimized instructions */ |
55479f64 | 818 | static struct kprobe *alloc_aggr_kprobe(struct kprobe *p) |
afd66255 MH |
819 | { |
820 | struct optimized_kprobe *op; | |
821 | ||
822 | op = kzalloc(sizeof(struct optimized_kprobe), GFP_KERNEL); | |
823 | if (!op) | |
824 | return NULL; | |
825 | ||
826 | INIT_LIST_HEAD(&op->list); | |
827 | op->kp.addr = p->addr; | |
a460246c | 828 | __prepare_optimized_kprobe(op, p); |
afd66255 MH |
829 | |
830 | return &op->kp; | |
831 | } | |
832 | ||
55479f64 | 833 | static void init_aggr_kprobe(struct kprobe *ap, struct kprobe *p); |
afd66255 MH |
834 | |
835 | /* | |
836 | * Prepare an optimized_kprobe and optimize it | |
837 | * NOTE: p must be a normal registered kprobe | |
838 | */ | |
55479f64 | 839 | static void try_to_optimize_kprobe(struct kprobe *p) |
afd66255 MH |
840 | { |
841 | struct kprobe *ap; | |
842 | struct optimized_kprobe *op; | |
843 | ||
ae6aa16f MH |
844 | /* Impossible to optimize ftrace-based kprobe */ |
845 | if (kprobe_ftrace(p)) | |
846 | return; | |
847 | ||
25764288 | 848 | /* For preparing optimization, jump_label_text_reserved() is called */ |
2d1e38f5 | 849 | cpus_read_lock(); |
25764288 MH |
850 | jump_label_lock(); |
851 | mutex_lock(&text_mutex); | |
852 | ||
afd66255 MH |
853 | ap = alloc_aggr_kprobe(p); |
854 | if (!ap) | |
25764288 | 855 | goto out; |
afd66255 MH |
856 | |
857 | op = container_of(ap, struct optimized_kprobe, kp); | |
858 | if (!arch_prepared_optinsn(&op->optinsn)) { | |
859 | /* If failed to setup optimizing, fallback to kprobe */ | |
6274de49 MH |
860 | arch_remove_optimized_kprobe(op); |
861 | kfree(op); | |
25764288 | 862 | goto out; |
afd66255 MH |
863 | } |
864 | ||
865 | init_aggr_kprobe(ap, p); | |
25764288 MH |
866 | optimize_kprobe(ap); /* This just kicks optimizer thread */ |
867 | ||
868 | out: | |
869 | mutex_unlock(&text_mutex); | |
870 | jump_label_unlock(); | |
2d1e38f5 | 871 | cpus_read_unlock(); |
afd66255 MH |
872 | } |
873 | ||
b2be84df | 874 | #ifdef CONFIG_SYSCTL |
55479f64 | 875 | static void optimize_all_kprobes(void) |
b2be84df MH |
876 | { |
877 | struct hlist_head *head; | |
b2be84df MH |
878 | struct kprobe *p; |
879 | unsigned int i; | |
880 | ||
5c51543b | 881 | mutex_lock(&kprobe_mutex); |
b2be84df MH |
882 | /* If optimization is already allowed, just return */ |
883 | if (kprobes_allow_optimization) | |
5c51543b | 884 | goto out; |
b2be84df | 885 | |
2d1e38f5 | 886 | cpus_read_lock(); |
b2be84df | 887 | kprobes_allow_optimization = true; |
b2be84df MH |
888 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
889 | head = &kprobe_table[i]; | |
7e6a71d8 | 890 | hlist_for_each_entry(p, head, hlist) |
b2be84df MH |
891 | if (!kprobe_disabled(p)) |
892 | optimize_kprobe(p); | |
893 | } | |
2d1e38f5 | 894 | cpus_read_unlock(); |
b2be84df | 895 | printk(KERN_INFO "Kprobes globally optimized\n"); |
5c51543b MH |
896 | out: |
897 | mutex_unlock(&kprobe_mutex); | |
b2be84df MH |
898 | } |
899 | ||
55479f64 | 900 | static void unoptimize_all_kprobes(void) |
b2be84df MH |
901 | { |
902 | struct hlist_head *head; | |
b2be84df MH |
903 | struct kprobe *p; |
904 | unsigned int i; | |
905 | ||
5c51543b | 906 | mutex_lock(&kprobe_mutex); |
b2be84df | 907 | /* If optimization is already prohibited, just return */ |
5c51543b MH |
908 | if (!kprobes_allow_optimization) { |
909 | mutex_unlock(&kprobe_mutex); | |
b2be84df | 910 | return; |
5c51543b | 911 | } |
b2be84df | 912 | |
2d1e38f5 | 913 | cpus_read_lock(); |
b2be84df | 914 | kprobes_allow_optimization = false; |
b2be84df MH |
915 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
916 | head = &kprobe_table[i]; | |
7e6a71d8 | 917 | hlist_for_each_entry(p, head, hlist) { |
b2be84df | 918 | if (!kprobe_disabled(p)) |
6274de49 | 919 | unoptimize_kprobe(p, false); |
b2be84df MH |
920 | } |
921 | } | |
2d1e38f5 | 922 | cpus_read_unlock(); |
5c51543b MH |
923 | mutex_unlock(&kprobe_mutex); |
924 | ||
6274de49 MH |
925 | /* Wait for unoptimizing completion */ |
926 | wait_for_kprobe_optimizer(); | |
927 | printk(KERN_INFO "Kprobes globally unoptimized\n"); | |
b2be84df MH |
928 | } |
929 | ||
5c51543b | 930 | static DEFINE_MUTEX(kprobe_sysctl_mutex); |
b2be84df MH |
931 | int sysctl_kprobes_optimization; |
932 | int proc_kprobes_optimization_handler(struct ctl_table *table, int write, | |
32927393 | 933 | void *buffer, size_t *length, |
b2be84df MH |
934 | loff_t *ppos) |
935 | { | |
936 | int ret; | |
937 | ||
5c51543b | 938 | mutex_lock(&kprobe_sysctl_mutex); |
b2be84df MH |
939 | sysctl_kprobes_optimization = kprobes_allow_optimization ? 1 : 0; |
940 | ret = proc_dointvec_minmax(table, write, buffer, length, ppos); | |
941 | ||
942 | if (sysctl_kprobes_optimization) | |
943 | optimize_all_kprobes(); | |
944 | else | |
945 | unoptimize_all_kprobes(); | |
5c51543b | 946 | mutex_unlock(&kprobe_sysctl_mutex); |
b2be84df MH |
947 | |
948 | return ret; | |
949 | } | |
950 | #endif /* CONFIG_SYSCTL */ | |
951 | ||
6274de49 | 952 | /* Put a breakpoint for a probe. Must be called with text_mutex locked */ |
55479f64 | 953 | static void __arm_kprobe(struct kprobe *p) |
afd66255 | 954 | { |
6d8e40a8 | 955 | struct kprobe *_p; |
afd66255 MH |
956 | |
957 | /* Check collision with other optimized kprobes */ | |
6d8e40a8 MH |
958 | _p = get_optimized_kprobe((unsigned long)p->addr); |
959 | if (unlikely(_p)) | |
6274de49 MH |
960 | /* Fallback to unoptimized kprobe */ |
961 | unoptimize_kprobe(_p, true); | |
afd66255 MH |
962 | |
963 | arch_arm_kprobe(p); | |
964 | optimize_kprobe(p); /* Try to optimize (add kprobe to a list) */ | |
965 | } | |
966 | ||
6274de49 | 967 | /* Remove the breakpoint of a probe. Must be called with text_mutex locked */ |
55479f64 | 968 | static void __disarm_kprobe(struct kprobe *p, bool reopt) |
afd66255 | 969 | { |
6d8e40a8 | 970 | struct kprobe *_p; |
afd66255 | 971 | |
69d54b91 WN |
972 | /* Try to unoptimize */ |
973 | unoptimize_kprobe(p, kprobes_all_disarmed); | |
afd66255 | 974 | |
6274de49 MH |
975 | if (!kprobe_queued(p)) { |
976 | arch_disarm_kprobe(p); | |
977 | /* If another kprobe was blocked, optimize it. */ | |
978 | _p = get_optimized_kprobe((unsigned long)p->addr); | |
979 | if (unlikely(_p) && reopt) | |
980 | optimize_kprobe(_p); | |
981 | } | |
982 | /* TODO: reoptimize others after unoptimized this probe */ | |
afd66255 MH |
983 | } |
984 | ||
985 | #else /* !CONFIG_OPTPROBES */ | |
986 | ||
987 | #define optimize_kprobe(p) do {} while (0) | |
6274de49 | 988 | #define unoptimize_kprobe(p, f) do {} while (0) |
afd66255 MH |
989 | #define kill_optimized_kprobe(p) do {} while (0) |
990 | #define prepare_optimized_kprobe(p) do {} while (0) | |
991 | #define try_to_optimize_kprobe(p) do {} while (0) | |
992 | #define __arm_kprobe(p) arch_arm_kprobe(p) | |
6274de49 MH |
993 | #define __disarm_kprobe(p, o) arch_disarm_kprobe(p) |
994 | #define kprobe_disarmed(p) kprobe_disabled(p) | |
995 | #define wait_for_kprobe_optimizer() do {} while (0) | |
afd66255 | 996 | |
819319fc | 997 | static int reuse_unused_kprobe(struct kprobe *ap) |
0490cd1f | 998 | { |
819319fc MH |
999 | /* |
1000 | * If the optimized kprobe is NOT supported, the aggr kprobe is | |
1001 | * released at the same time that the last aggregated kprobe is | |
1002 | * unregistered. | |
1003 | * Thus there should be no chance to reuse unused kprobe. | |
1004 | */ | |
0490cd1f | 1005 | printk(KERN_ERR "Error: There should be no unused kprobe here.\n"); |
819319fc | 1006 | return -EINVAL; |
0490cd1f MH |
1007 | } |
1008 | ||
55479f64 | 1009 | static void free_aggr_kprobe(struct kprobe *p) |
afd66255 | 1010 | { |
6274de49 | 1011 | arch_remove_kprobe(p); |
afd66255 MH |
1012 | kfree(p); |
1013 | } | |
1014 | ||
55479f64 | 1015 | static struct kprobe *alloc_aggr_kprobe(struct kprobe *p) |
afd66255 MH |
1016 | { |
1017 | return kzalloc(sizeof(struct kprobe), GFP_KERNEL); | |
1018 | } | |
1019 | #endif /* CONFIG_OPTPROBES */ | |
1020 | ||
e7dbfe34 | 1021 | #ifdef CONFIG_KPROBES_ON_FTRACE |
ae6aa16f | 1022 | static struct ftrace_ops kprobe_ftrace_ops __read_mostly = { |
0bc11ed5 MH |
1023 | .func = kprobe_ftrace_handler, |
1024 | .flags = FTRACE_OPS_FL_SAVE_REGS, | |
1025 | }; | |
1026 | ||
1027 | static struct ftrace_ops kprobe_ipmodify_ops __read_mostly = { | |
e5253896 | 1028 | .func = kprobe_ftrace_handler, |
1d70be34 | 1029 | .flags = FTRACE_OPS_FL_SAVE_REGS | FTRACE_OPS_FL_IPMODIFY, |
ae6aa16f | 1030 | }; |
0bc11ed5 MH |
1031 | |
1032 | static int kprobe_ipmodify_enabled; | |
ae6aa16f MH |
1033 | static int kprobe_ftrace_enabled; |
1034 | ||
1035 | /* Must ensure p->addr is really on ftrace */ | |
55479f64 | 1036 | static int prepare_kprobe(struct kprobe *p) |
ae6aa16f MH |
1037 | { |
1038 | if (!kprobe_ftrace(p)) | |
1039 | return arch_prepare_kprobe(p); | |
1040 | ||
1041 | return arch_prepare_kprobe_ftrace(p); | |
1042 | } | |
1043 | ||
1044 | /* Caller must lock kprobe_mutex */ | |
0bc11ed5 MH |
1045 | static int __arm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops, |
1046 | int *cnt) | |
ae6aa16f | 1047 | { |
12310e34 | 1048 | int ret = 0; |
ae6aa16f | 1049 | |
0bc11ed5 | 1050 | ret = ftrace_set_filter_ip(ops, (unsigned long)p->addr, 0, 0); |
12310e34 | 1051 | if (ret) { |
4458515b MH |
1052 | pr_debug("Failed to arm kprobe-ftrace at %pS (%d)\n", |
1053 | p->addr, ret); | |
12310e34 JY |
1054 | return ret; |
1055 | } | |
1056 | ||
0bc11ed5 MH |
1057 | if (*cnt == 0) { |
1058 | ret = register_ftrace_function(ops); | |
12310e34 JY |
1059 | if (ret) { |
1060 | pr_debug("Failed to init kprobe-ftrace (%d)\n", ret); | |
1061 | goto err_ftrace; | |
1062 | } | |
ae6aa16f | 1063 | } |
12310e34 | 1064 | |
0bc11ed5 | 1065 | (*cnt)++; |
12310e34 JY |
1066 | return ret; |
1067 | ||
1068 | err_ftrace: | |
1069 | /* | |
0bc11ed5 MH |
1070 | * At this point, sinec ops is not registered, we should be sefe from |
1071 | * registering empty filter. | |
12310e34 | 1072 | */ |
0bc11ed5 | 1073 | ftrace_set_filter_ip(ops, (unsigned long)p->addr, 1, 0); |
12310e34 | 1074 | return ret; |
ae6aa16f MH |
1075 | } |
1076 | ||
0bc11ed5 MH |
1077 | static int arm_kprobe_ftrace(struct kprobe *p) |
1078 | { | |
1079 | bool ipmodify = (p->post_handler != NULL); | |
1080 | ||
1081 | return __arm_kprobe_ftrace(p, | |
1082 | ipmodify ? &kprobe_ipmodify_ops : &kprobe_ftrace_ops, | |
1083 | ipmodify ? &kprobe_ipmodify_enabled : &kprobe_ftrace_enabled); | |
1084 | } | |
1085 | ||
ae6aa16f | 1086 | /* Caller must lock kprobe_mutex */ |
0bc11ed5 MH |
1087 | static int __disarm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops, |
1088 | int *cnt) | |
ae6aa16f | 1089 | { |
297f9233 | 1090 | int ret = 0; |
ae6aa16f | 1091 | |
0bc11ed5 MH |
1092 | if (*cnt == 1) { |
1093 | ret = unregister_ftrace_function(ops); | |
297f9233 JY |
1094 | if (WARN(ret < 0, "Failed to unregister kprobe-ftrace (%d)\n", ret)) |
1095 | return ret; | |
ae6aa16f | 1096 | } |
297f9233 | 1097 | |
0bc11ed5 | 1098 | (*cnt)--; |
297f9233 | 1099 | |
0bc11ed5 | 1100 | ret = ftrace_set_filter_ip(ops, (unsigned long)p->addr, 1, 0); |
4458515b MH |
1101 | WARN_ONCE(ret < 0, "Failed to disarm kprobe-ftrace at %pS (%d)\n", |
1102 | p->addr, ret); | |
297f9233 | 1103 | return ret; |
ae6aa16f | 1104 | } |
0bc11ed5 MH |
1105 | |
1106 | static int disarm_kprobe_ftrace(struct kprobe *p) | |
1107 | { | |
1108 | bool ipmodify = (p->post_handler != NULL); | |
1109 | ||
1110 | return __disarm_kprobe_ftrace(p, | |
1111 | ipmodify ? &kprobe_ipmodify_ops : &kprobe_ftrace_ops, | |
1112 | ipmodify ? &kprobe_ipmodify_enabled : &kprobe_ftrace_enabled); | |
1113 | } | |
e7dbfe34 | 1114 | #else /* !CONFIG_KPROBES_ON_FTRACE */ |
10de795a MS |
1115 | static inline int prepare_kprobe(struct kprobe *p) |
1116 | { | |
1117 | return arch_prepare_kprobe(p); | |
1118 | } | |
1119 | ||
1120 | static inline int arm_kprobe_ftrace(struct kprobe *p) | |
1121 | { | |
1122 | return -ENODEV; | |
1123 | } | |
1124 | ||
1125 | static inline int disarm_kprobe_ftrace(struct kprobe *p) | |
1126 | { | |
1127 | return -ENODEV; | |
1128 | } | |
ae6aa16f MH |
1129 | #endif |
1130 | ||
201517a7 | 1131 | /* Arm a kprobe with text_mutex */ |
12310e34 | 1132 | static int arm_kprobe(struct kprobe *kp) |
201517a7 | 1133 | { |
12310e34 JY |
1134 | if (unlikely(kprobe_ftrace(kp))) |
1135 | return arm_kprobe_ftrace(kp); | |
1136 | ||
2d1e38f5 | 1137 | cpus_read_lock(); |
201517a7 | 1138 | mutex_lock(&text_mutex); |
afd66255 | 1139 | __arm_kprobe(kp); |
201517a7 | 1140 | mutex_unlock(&text_mutex); |
2d1e38f5 | 1141 | cpus_read_unlock(); |
12310e34 JY |
1142 | |
1143 | return 0; | |
201517a7 MH |
1144 | } |
1145 | ||
1146 | /* Disarm a kprobe with text_mutex */ | |
297f9233 | 1147 | static int disarm_kprobe(struct kprobe *kp, bool reopt) |
201517a7 | 1148 | { |
297f9233 JY |
1149 | if (unlikely(kprobe_ftrace(kp))) |
1150 | return disarm_kprobe_ftrace(kp); | |
2d1e38f5 TG |
1151 | |
1152 | cpus_read_lock(); | |
201517a7 | 1153 | mutex_lock(&text_mutex); |
ae6aa16f | 1154 | __disarm_kprobe(kp, reopt); |
201517a7 | 1155 | mutex_unlock(&text_mutex); |
2d1e38f5 | 1156 | cpus_read_unlock(); |
297f9233 JY |
1157 | |
1158 | return 0; | |
201517a7 MH |
1159 | } |
1160 | ||
64f562c6 AM |
1161 | /* |
1162 | * Aggregate handlers for multiple kprobes support - these handlers | |
1163 | * take care of invoking the individual kprobe handlers on p->list | |
1164 | */ | |
820aede0 | 1165 | static int aggr_pre_handler(struct kprobe *p, struct pt_regs *regs) |
64f562c6 AM |
1166 | { |
1167 | struct kprobe *kp; | |
1168 | ||
3516a460 | 1169 | list_for_each_entry_rcu(kp, &p->list, list) { |
de5bd88d | 1170 | if (kp->pre_handler && likely(!kprobe_disabled(kp))) { |
e6584523 | 1171 | set_kprobe_instance(kp); |
8b0914ea PP |
1172 | if (kp->pre_handler(kp, regs)) |
1173 | return 1; | |
64f562c6 | 1174 | } |
e6584523 | 1175 | reset_kprobe_instance(); |
64f562c6 AM |
1176 | } |
1177 | return 0; | |
1178 | } | |
820aede0 | 1179 | NOKPROBE_SYMBOL(aggr_pre_handler); |
64f562c6 | 1180 | |
820aede0 MH |
1181 | static void aggr_post_handler(struct kprobe *p, struct pt_regs *regs, |
1182 | unsigned long flags) | |
64f562c6 AM |
1183 | { |
1184 | struct kprobe *kp; | |
1185 | ||
3516a460 | 1186 | list_for_each_entry_rcu(kp, &p->list, list) { |
de5bd88d | 1187 | if (kp->post_handler && likely(!kprobe_disabled(kp))) { |
e6584523 | 1188 | set_kprobe_instance(kp); |
64f562c6 | 1189 | kp->post_handler(kp, regs, flags); |
e6584523 | 1190 | reset_kprobe_instance(); |
64f562c6 AM |
1191 | } |
1192 | } | |
64f562c6 | 1193 | } |
820aede0 | 1194 | NOKPROBE_SYMBOL(aggr_post_handler); |
64f562c6 | 1195 | |
820aede0 MH |
1196 | static int aggr_fault_handler(struct kprobe *p, struct pt_regs *regs, |
1197 | int trapnr) | |
64f562c6 | 1198 | { |
b76834bc | 1199 | struct kprobe *cur = __this_cpu_read(kprobe_instance); |
e6584523 | 1200 | |
64f562c6 AM |
1201 | /* |
1202 | * if we faulted "during" the execution of a user specified | |
1203 | * probe handler, invoke just that probe's fault handler | |
1204 | */ | |
e6584523 AM |
1205 | if (cur && cur->fault_handler) { |
1206 | if (cur->fault_handler(cur, regs, trapnr)) | |
64f562c6 AM |
1207 | return 1; |
1208 | } | |
1209 | return 0; | |
1210 | } | |
820aede0 | 1211 | NOKPROBE_SYMBOL(aggr_fault_handler); |
64f562c6 | 1212 | |
bf8d5c52 | 1213 | /* Walks the list and increments nmissed count for multiprobe case */ |
820aede0 | 1214 | void kprobes_inc_nmissed_count(struct kprobe *p) |
bf8d5c52 KA |
1215 | { |
1216 | struct kprobe *kp; | |
afd66255 | 1217 | if (!kprobe_aggrprobe(p)) { |
bf8d5c52 KA |
1218 | p->nmissed++; |
1219 | } else { | |
1220 | list_for_each_entry_rcu(kp, &p->list, list) | |
1221 | kp->nmissed++; | |
1222 | } | |
1223 | return; | |
1224 | } | |
820aede0 | 1225 | NOKPROBE_SYMBOL(kprobes_inc_nmissed_count); |
bf8d5c52 | 1226 | |
b3388178 | 1227 | static void recycle_rp_inst(struct kretprobe_instance *ri) |
b94cce92 | 1228 | { |
ef53d9c5 S |
1229 | struct kretprobe *rp = ri->rp; |
1230 | ||
b94cce92 HN |
1231 | /* remove rp inst off the rprobe_inst_table */ |
1232 | hlist_del(&ri->hlist); | |
ef53d9c5 S |
1233 | INIT_HLIST_NODE(&ri->hlist); |
1234 | if (likely(rp)) { | |
ec484608 | 1235 | raw_spin_lock(&rp->lock); |
ef53d9c5 | 1236 | hlist_add_head(&ri->hlist, &rp->free_instances); |
ec484608 | 1237 | raw_spin_unlock(&rp->lock); |
b94cce92 | 1238 | } else |
b3388178 | 1239 | kfree_rcu(ri, rcu); |
b94cce92 | 1240 | } |
820aede0 | 1241 | NOKPROBE_SYMBOL(recycle_rp_inst); |
b94cce92 | 1242 | |
319f0ce2 | 1243 | static void kretprobe_hash_lock(struct task_struct *tsk, |
ef53d9c5 | 1244 | struct hlist_head **head, unsigned long *flags) |
635c17c2 | 1245 | __acquires(hlist_lock) |
ef53d9c5 S |
1246 | { |
1247 | unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS); | |
ec484608 | 1248 | raw_spinlock_t *hlist_lock; |
ef53d9c5 S |
1249 | |
1250 | *head = &kretprobe_inst_table[hash]; | |
1251 | hlist_lock = kretprobe_table_lock_ptr(hash); | |
645f224e SRV |
1252 | /* |
1253 | * Nested is a workaround that will soon not be needed. | |
1254 | * There's other protections that make sure the same lock | |
1255 | * is not taken on the same CPU that lockdep is unaware of. | |
1256 | * Differentiate when it is taken in NMI context. | |
1257 | */ | |
1258 | raw_spin_lock_irqsave_nested(hlist_lock, *flags, !!in_nmi()); | |
ef53d9c5 | 1259 | } |
820aede0 | 1260 | NOKPROBE_SYMBOL(kretprobe_hash_lock); |
ef53d9c5 | 1261 | |
820aede0 MH |
1262 | static void kretprobe_table_lock(unsigned long hash, |
1263 | unsigned long *flags) | |
635c17c2 | 1264 | __acquires(hlist_lock) |
b94cce92 | 1265 | { |
ec484608 | 1266 | raw_spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash); |
645f224e SRV |
1267 | /* |
1268 | * Nested is a workaround that will soon not be needed. | |
1269 | * There's other protections that make sure the same lock | |
1270 | * is not taken on the same CPU that lockdep is unaware of. | |
1271 | * Differentiate when it is taken in NMI context. | |
1272 | */ | |
1273 | raw_spin_lock_irqsave_nested(hlist_lock, *flags, !!in_nmi()); | |
ef53d9c5 | 1274 | } |
820aede0 | 1275 | NOKPROBE_SYMBOL(kretprobe_table_lock); |
ef53d9c5 | 1276 | |
319f0ce2 | 1277 | static void kretprobe_hash_unlock(struct task_struct *tsk, |
820aede0 | 1278 | unsigned long *flags) |
635c17c2 | 1279 | __releases(hlist_lock) |
ef53d9c5 S |
1280 | { |
1281 | unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS); | |
ec484608 | 1282 | raw_spinlock_t *hlist_lock; |
ef53d9c5 S |
1283 | |
1284 | hlist_lock = kretprobe_table_lock_ptr(hash); | |
ec484608 | 1285 | raw_spin_unlock_irqrestore(hlist_lock, *flags); |
ef53d9c5 | 1286 | } |
820aede0 | 1287 | NOKPROBE_SYMBOL(kretprobe_hash_unlock); |
ef53d9c5 | 1288 | |
820aede0 MH |
1289 | static void kretprobe_table_unlock(unsigned long hash, |
1290 | unsigned long *flags) | |
635c17c2 | 1291 | __releases(hlist_lock) |
ef53d9c5 | 1292 | { |
ec484608 TG |
1293 | raw_spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash); |
1294 | raw_spin_unlock_irqrestore(hlist_lock, *flags); | |
b94cce92 | 1295 | } |
820aede0 | 1296 | NOKPROBE_SYMBOL(kretprobe_table_unlock); |
b94cce92 | 1297 | |
319f0ce2 | 1298 | static struct kprobe kprobe_busy = { |
9b38cc70 JO |
1299 | .addr = (void *) get_kprobe, |
1300 | }; | |
1301 | ||
1302 | void kprobe_busy_begin(void) | |
1303 | { | |
1304 | struct kprobe_ctlblk *kcb; | |
1305 | ||
1306 | preempt_disable(); | |
1307 | __this_cpu_write(current_kprobe, &kprobe_busy); | |
1308 | kcb = get_kprobe_ctlblk(); | |
1309 | kcb->kprobe_status = KPROBE_HIT_ACTIVE; | |
1310 | } | |
1311 | ||
1312 | void kprobe_busy_end(void) | |
1313 | { | |
1314 | __this_cpu_write(current_kprobe, NULL); | |
1315 | preempt_enable(); | |
1316 | } | |
1317 | ||
b94cce92 | 1318 | /* |
c6fd91f0 | 1319 | * This function is called from finish_task_switch when task tk becomes dead, |
1320 | * so that we can recycle any function-return probe instances associated | |
1321 | * with this task. These left over instances represent probed functions | |
1322 | * that have been called but will never return. | |
b94cce92 | 1323 | */ |
820aede0 | 1324 | void kprobe_flush_task(struct task_struct *tk) |
b94cce92 | 1325 | { |
62c27be0 | 1326 | struct kretprobe_instance *ri; |
b3388178 | 1327 | struct hlist_head *head; |
b67bfe0d | 1328 | struct hlist_node *tmp; |
ef53d9c5 | 1329 | unsigned long hash, flags = 0; |
802eae7c | 1330 | |
ef53d9c5 S |
1331 | if (unlikely(!kprobes_initialized)) |
1332 | /* Early boot. kretprobe_table_locks not yet initialized. */ | |
1333 | return; | |
1334 | ||
9b38cc70 JO |
1335 | kprobe_busy_begin(); |
1336 | ||
ef53d9c5 S |
1337 | hash = hash_ptr(tk, KPROBE_HASH_BITS); |
1338 | head = &kretprobe_inst_table[hash]; | |
1339 | kretprobe_table_lock(hash, &flags); | |
b67bfe0d | 1340 | hlist_for_each_entry_safe(ri, tmp, head, hlist) { |
62c27be0 | 1341 | if (ri->task == tk) |
b3388178 | 1342 | recycle_rp_inst(ri); |
62c27be0 | 1343 | } |
ef53d9c5 | 1344 | kretprobe_table_unlock(hash, &flags); |
9b38cc70 JO |
1345 | |
1346 | kprobe_busy_end(); | |
b94cce92 | 1347 | } |
820aede0 | 1348 | NOKPROBE_SYMBOL(kprobe_flush_task); |
b94cce92 | 1349 | |
b94cce92 HN |
1350 | static inline void free_rp_inst(struct kretprobe *rp) |
1351 | { | |
1352 | struct kretprobe_instance *ri; | |
b67bfe0d | 1353 | struct hlist_node *next; |
4c4308cb | 1354 | |
b67bfe0d | 1355 | hlist_for_each_entry_safe(ri, next, &rp->free_instances, hlist) { |
ef53d9c5 | 1356 | hlist_del(&ri->hlist); |
b94cce92 HN |
1357 | kfree(ri); |
1358 | } | |
1359 | } | |
1360 | ||
820aede0 | 1361 | static void cleanup_rp_inst(struct kretprobe *rp) |
4a296e07 | 1362 | { |
ef53d9c5 | 1363 | unsigned long flags, hash; |
4a296e07 | 1364 | struct kretprobe_instance *ri; |
b67bfe0d | 1365 | struct hlist_node *next; |
ef53d9c5 S |
1366 | struct hlist_head *head; |
1367 | ||
e03b4a08 MH |
1368 | /* To avoid recursive kretprobe by NMI, set kprobe busy here */ |
1369 | kprobe_busy_begin(); | |
ef53d9c5 S |
1370 | for (hash = 0; hash < KPROBE_TABLE_SIZE; hash++) { |
1371 | kretprobe_table_lock(hash, &flags); | |
1372 | head = &kretprobe_inst_table[hash]; | |
b67bfe0d | 1373 | hlist_for_each_entry_safe(ri, next, head, hlist) { |
ef53d9c5 S |
1374 | if (ri->rp == rp) |
1375 | ri->rp = NULL; | |
1376 | } | |
1377 | kretprobe_table_unlock(hash, &flags); | |
4a296e07 | 1378 | } |
e03b4a08 MH |
1379 | kprobe_busy_end(); |
1380 | ||
4a296e07 MH |
1381 | free_rp_inst(rp); |
1382 | } | |
820aede0 | 1383 | NOKPROBE_SYMBOL(cleanup_rp_inst); |
4a296e07 | 1384 | |
059053a2 | 1385 | /* Add the new probe to ap->list */ |
55479f64 | 1386 | static int add_new_kprobe(struct kprobe *ap, struct kprobe *p) |
8b0914ea | 1387 | { |
059053a2 | 1388 | if (p->post_handler) |
6274de49 | 1389 | unoptimize_kprobe(ap, true); /* Fall back to normal kprobe */ |
afd66255 | 1390 | |
059053a2 | 1391 | list_add_rcu(&p->list, &ap->list); |
b918e5e6 MH |
1392 | if (p->post_handler && !ap->post_handler) |
1393 | ap->post_handler = aggr_post_handler; | |
de5bd88d | 1394 | |
8b0914ea PP |
1395 | return 0; |
1396 | } | |
1397 | ||
64f562c6 AM |
1398 | /* |
1399 | * Fill in the required fields of the "manager kprobe". Replace the | |
1400 | * earlier kprobe in the hlist with the manager kprobe | |
1401 | */ | |
55479f64 | 1402 | static void init_aggr_kprobe(struct kprobe *ap, struct kprobe *p) |
64f562c6 | 1403 | { |
afd66255 | 1404 | /* Copy p's insn slot to ap */ |
8b0914ea | 1405 | copy_kprobe(p, ap); |
a9ad965e | 1406 | flush_insn_slot(ap); |
64f562c6 | 1407 | ap->addr = p->addr; |
afd66255 | 1408 | ap->flags = p->flags & ~KPROBE_FLAG_OPTIMIZED; |
64f562c6 | 1409 | ap->pre_handler = aggr_pre_handler; |
64f562c6 | 1410 | ap->fault_handler = aggr_fault_handler; |
e8386a0c MH |
1411 | /* We don't care the kprobe which has gone. */ |
1412 | if (p->post_handler && !kprobe_gone(p)) | |
36721656 | 1413 | ap->post_handler = aggr_post_handler; |
64f562c6 AM |
1414 | |
1415 | INIT_LIST_HEAD(&ap->list); | |
afd66255 | 1416 | INIT_HLIST_NODE(&ap->hlist); |
64f562c6 | 1417 | |
afd66255 | 1418 | list_add_rcu(&p->list, &ap->list); |
adad0f33 | 1419 | hlist_replace_rcu(&p->hlist, &ap->hlist); |
64f562c6 AM |
1420 | } |
1421 | ||
1422 | /* | |
1423 | * This is the second or subsequent kprobe at the address - handle | |
1424 | * the intricacies | |
64f562c6 | 1425 | */ |
55479f64 | 1426 | static int register_aggr_kprobe(struct kprobe *orig_p, struct kprobe *p) |
64f562c6 AM |
1427 | { |
1428 | int ret = 0; | |
6d8e40a8 | 1429 | struct kprobe *ap = orig_p; |
64f562c6 | 1430 | |
2d1e38f5 TG |
1431 | cpus_read_lock(); |
1432 | ||
25764288 MH |
1433 | /* For preparing optimization, jump_label_text_reserved() is called */ |
1434 | jump_label_lock(); | |
25764288 MH |
1435 | mutex_lock(&text_mutex); |
1436 | ||
6d8e40a8 MH |
1437 | if (!kprobe_aggrprobe(orig_p)) { |
1438 | /* If orig_p is not an aggr_kprobe, create new aggr_kprobe. */ | |
1439 | ap = alloc_aggr_kprobe(orig_p); | |
25764288 MH |
1440 | if (!ap) { |
1441 | ret = -ENOMEM; | |
1442 | goto out; | |
1443 | } | |
6d8e40a8 | 1444 | init_aggr_kprobe(ap, orig_p); |
819319fc | 1445 | } else if (kprobe_unused(ap)) { |
0490cd1f | 1446 | /* This probe is going to die. Rescue it */ |
819319fc MH |
1447 | ret = reuse_unused_kprobe(ap); |
1448 | if (ret) | |
1449 | goto out; | |
1450 | } | |
b918e5e6 MH |
1451 | |
1452 | if (kprobe_gone(ap)) { | |
e8386a0c MH |
1453 | /* |
1454 | * Attempting to insert new probe at the same location that | |
1455 | * had a probe in the module vaddr area which already | |
1456 | * freed. So, the instruction slot has already been | |
1457 | * released. We need a new slot for the new probe. | |
1458 | */ | |
b918e5e6 | 1459 | ret = arch_prepare_kprobe(ap); |
e8386a0c | 1460 | if (ret) |
b918e5e6 MH |
1461 | /* |
1462 | * Even if fail to allocate new slot, don't need to | |
1463 | * free aggr_probe. It will be used next time, or | |
1464 | * freed by unregister_kprobe. | |
1465 | */ | |
25764288 | 1466 | goto out; |
de5bd88d | 1467 | |
afd66255 MH |
1468 | /* Prepare optimized instructions if possible. */ |
1469 | prepare_optimized_kprobe(ap); | |
1470 | ||
e8386a0c | 1471 | /* |
de5bd88d MH |
1472 | * Clear gone flag to prevent allocating new slot again, and |
1473 | * set disabled flag because it is not armed yet. | |
e8386a0c | 1474 | */ |
de5bd88d MH |
1475 | ap->flags = (ap->flags & ~KPROBE_FLAG_GONE) |
1476 | | KPROBE_FLAG_DISABLED; | |
e8386a0c | 1477 | } |
b918e5e6 | 1478 | |
afd66255 | 1479 | /* Copy ap's insn slot to p */ |
b918e5e6 | 1480 | copy_kprobe(ap, p); |
25764288 MH |
1481 | ret = add_new_kprobe(ap, p); |
1482 | ||
1483 | out: | |
1484 | mutex_unlock(&text_mutex); | |
25764288 | 1485 | jump_label_unlock(); |
2d1e38f5 | 1486 | cpus_read_unlock(); |
25764288 MH |
1487 | |
1488 | if (ret == 0 && kprobe_disabled(ap) && !kprobe_disabled(p)) { | |
1489 | ap->flags &= ~KPROBE_FLAG_DISABLED; | |
12310e34 | 1490 | if (!kprobes_all_disarmed) { |
25764288 | 1491 | /* Arm the breakpoint again. */ |
12310e34 JY |
1492 | ret = arm_kprobe(ap); |
1493 | if (ret) { | |
1494 | ap->flags |= KPROBE_FLAG_DISABLED; | |
1495 | list_del_rcu(&p->list); | |
ae8b7ce7 | 1496 | synchronize_rcu(); |
12310e34 JY |
1497 | } |
1498 | } | |
25764288 MH |
1499 | } |
1500 | return ret; | |
64f562c6 AM |
1501 | } |
1502 | ||
be8f2743 MH |
1503 | bool __weak arch_within_kprobe_blacklist(unsigned long addr) |
1504 | { | |
1505 | /* The __kprobes marked functions and entry code must not be probed */ | |
1506 | return addr >= (unsigned long)__kprobes_text_start && | |
1507 | addr < (unsigned long)__kprobes_text_end; | |
1508 | } | |
1509 | ||
6143c6fb | 1510 | static bool __within_kprobe_blacklist(unsigned long addr) |
d0aaff97 | 1511 | { |
376e2424 | 1512 | struct kprobe_blacklist_entry *ent; |
3d8d996e | 1513 | |
be8f2743 | 1514 | if (arch_within_kprobe_blacklist(addr)) |
376e2424 | 1515 | return true; |
3d8d996e SD |
1516 | /* |
1517 | * If there exists a kprobe_blacklist, verify and | |
1518 | * fail any probe registration in the prohibited area | |
1519 | */ | |
376e2424 MH |
1520 | list_for_each_entry(ent, &kprobe_blacklist, list) { |
1521 | if (addr >= ent->start_addr && addr < ent->end_addr) | |
1522 | return true; | |
3d8d996e | 1523 | } |
6143c6fb MH |
1524 | return false; |
1525 | } | |
376e2424 | 1526 | |
6143c6fb MH |
1527 | bool within_kprobe_blacklist(unsigned long addr) |
1528 | { | |
1529 | char symname[KSYM_NAME_LEN], *p; | |
1530 | ||
1531 | if (__within_kprobe_blacklist(addr)) | |
1532 | return true; | |
1533 | ||
1534 | /* Check if the address is on a suffixed-symbol */ | |
1535 | if (!lookup_symbol_name(addr, symname)) { | |
1536 | p = strchr(symname, '.'); | |
1537 | if (!p) | |
1538 | return false; | |
1539 | *p = '\0'; | |
1540 | addr = (unsigned long)kprobe_lookup_name(symname, 0); | |
1541 | if (addr) | |
1542 | return __within_kprobe_blacklist(addr); | |
1543 | } | |
376e2424 | 1544 | return false; |
d0aaff97 PP |
1545 | } |
1546 | ||
b2a5cd69 MH |
1547 | /* |
1548 | * If we have a symbol_name argument, look it up and add the offset field | |
1549 | * to it. This way, we can specify a relative address to a symbol. | |
bc81d48d MH |
1550 | * This returns encoded errors if it fails to look up symbol or invalid |
1551 | * combination of parameters. | |
b2a5cd69 | 1552 | */ |
1d585e70 NR |
1553 | static kprobe_opcode_t *_kprobe_addr(kprobe_opcode_t *addr, |
1554 | const char *symbol_name, unsigned int offset) | |
b2a5cd69 | 1555 | { |
1d585e70 | 1556 | if ((symbol_name && addr) || (!symbol_name && !addr)) |
bc81d48d MH |
1557 | goto invalid; |
1558 | ||
1d585e70 | 1559 | if (symbol_name) { |
7246f600 | 1560 | addr = kprobe_lookup_name(symbol_name, offset); |
bc81d48d MH |
1561 | if (!addr) |
1562 | return ERR_PTR(-ENOENT); | |
b2a5cd69 MH |
1563 | } |
1564 | ||
1d585e70 | 1565 | addr = (kprobe_opcode_t *)(((char *)addr) + offset); |
bc81d48d MH |
1566 | if (addr) |
1567 | return addr; | |
1568 | ||
1569 | invalid: | |
1570 | return ERR_PTR(-EINVAL); | |
b2a5cd69 MH |
1571 | } |
1572 | ||
1d585e70 NR |
1573 | static kprobe_opcode_t *kprobe_addr(struct kprobe *p) |
1574 | { | |
1575 | return _kprobe_addr(p->addr, p->symbol_name, p->offset); | |
1576 | } | |
1577 | ||
1f0ab409 | 1578 | /* Check passed kprobe is valid and return kprobe in kprobe_table. */ |
55479f64 | 1579 | static struct kprobe *__get_valid_kprobe(struct kprobe *p) |
1f0ab409 | 1580 | { |
6d8e40a8 | 1581 | struct kprobe *ap, *list_p; |
1f0ab409 | 1582 | |
7e6a71d8 MH |
1583 | lockdep_assert_held(&kprobe_mutex); |
1584 | ||
6d8e40a8 MH |
1585 | ap = get_kprobe(p->addr); |
1586 | if (unlikely(!ap)) | |
1f0ab409 AM |
1587 | return NULL; |
1588 | ||
6d8e40a8 | 1589 | if (p != ap) { |
7e6a71d8 | 1590 | list_for_each_entry(list_p, &ap->list, list) |
1f0ab409 AM |
1591 | if (list_p == p) |
1592 | /* kprobe p is a valid probe */ | |
1593 | goto valid; | |
1594 | return NULL; | |
1595 | } | |
1596 | valid: | |
6d8e40a8 | 1597 | return ap; |
1f0ab409 AM |
1598 | } |
1599 | ||
1600 | /* Return error if the kprobe is being re-registered */ | |
1601 | static inline int check_kprobe_rereg(struct kprobe *p) | |
1602 | { | |
1603 | int ret = 0; | |
1f0ab409 AM |
1604 | |
1605 | mutex_lock(&kprobe_mutex); | |
6d8e40a8 | 1606 | if (__get_valid_kprobe(p)) |
1f0ab409 AM |
1607 | ret = -EINVAL; |
1608 | mutex_unlock(&kprobe_mutex); | |
6d8e40a8 | 1609 | |
1f0ab409 AM |
1610 | return ret; |
1611 | } | |
1612 | ||
f7f242ff | 1613 | int __weak arch_check_ftrace_location(struct kprobe *p) |
1da177e4 | 1614 | { |
ae6aa16f MH |
1615 | unsigned long ftrace_addr; |
1616 | ||
ae6aa16f MH |
1617 | ftrace_addr = ftrace_location((unsigned long)p->addr); |
1618 | if (ftrace_addr) { | |
e7dbfe34 | 1619 | #ifdef CONFIG_KPROBES_ON_FTRACE |
ae6aa16f MH |
1620 | /* Given address is not on the instruction boundary */ |
1621 | if ((unsigned long)p->addr != ftrace_addr) | |
1622 | return -EILSEQ; | |
ae6aa16f | 1623 | p->flags |= KPROBE_FLAG_FTRACE; |
e7dbfe34 | 1624 | #else /* !CONFIG_KPROBES_ON_FTRACE */ |
ae6aa16f MH |
1625 | return -EINVAL; |
1626 | #endif | |
1627 | } | |
f7f242ff HC |
1628 | return 0; |
1629 | } | |
1630 | ||
1631 | static int check_kprobe_address_safe(struct kprobe *p, | |
1632 | struct module **probed_mod) | |
1633 | { | |
1634 | int ret; | |
1f0ab409 | 1635 | |
f7f242ff HC |
1636 | ret = arch_check_ftrace_location(p); |
1637 | if (ret) | |
1638 | return ret; | |
91bad2f8 | 1639 | jump_label_lock(); |
de31c3ca | 1640 | preempt_disable(); |
f7fa6ef0 MH |
1641 | |
1642 | /* Ensure it is not in reserved area nor out of text */ | |
ec30c5f3 | 1643 | if (!kernel_text_address((unsigned long) p->addr) || |
376e2424 | 1644 | within_kprobe_blacklist((unsigned long) p->addr) || |
e336b402 | 1645 | jump_label_text_reserved(p->addr, p->addr) || |
6333e8f7 | 1646 | static_call_text_reserved(p->addr, p->addr) || |
e336b402 | 1647 | find_bug((unsigned long)p->addr)) { |
f986a499 | 1648 | ret = -EINVAL; |
f7fa6ef0 | 1649 | goto out; |
f986a499 | 1650 | } |
b3e55c72 | 1651 | |
f7fa6ef0 MH |
1652 | /* Check if are we probing a module */ |
1653 | *probed_mod = __module_text_address((unsigned long) p->addr); | |
1654 | if (*probed_mod) { | |
6f716acd | 1655 | /* |
e8386a0c MH |
1656 | * We must hold a refcount of the probed module while updating |
1657 | * its code to prohibit unexpected unloading. | |
df019b1d | 1658 | */ |
f7fa6ef0 MH |
1659 | if (unlikely(!try_module_get(*probed_mod))) { |
1660 | ret = -ENOENT; | |
1661 | goto out; | |
1662 | } | |
de31c3ca | 1663 | |
f24659d9 MH |
1664 | /* |
1665 | * If the module freed .init.text, we couldn't insert | |
1666 | * kprobes in there. | |
1667 | */ | |
f7fa6ef0 MH |
1668 | if (within_module_init((unsigned long)p->addr, *probed_mod) && |
1669 | (*probed_mod)->state != MODULE_STATE_COMING) { | |
1670 | module_put(*probed_mod); | |
1671 | *probed_mod = NULL; | |
1672 | ret = -ENOENT; | |
f24659d9 | 1673 | } |
df019b1d | 1674 | } |
f7fa6ef0 | 1675 | out: |
a189d035 | 1676 | preempt_enable(); |
de31c3ca | 1677 | jump_label_unlock(); |
1da177e4 | 1678 | |
f7fa6ef0 MH |
1679 | return ret; |
1680 | } | |
1681 | ||
55479f64 | 1682 | int register_kprobe(struct kprobe *p) |
f7fa6ef0 MH |
1683 | { |
1684 | int ret; | |
1685 | struct kprobe *old_p; | |
1686 | struct module *probed_mod; | |
1687 | kprobe_opcode_t *addr; | |
1688 | ||
1689 | /* Adjust probe address from symbol */ | |
1690 | addr = kprobe_addr(p); | |
1691 | if (IS_ERR(addr)) | |
1692 | return PTR_ERR(addr); | |
1693 | p->addr = addr; | |
1694 | ||
1695 | ret = check_kprobe_rereg(p); | |
1696 | if (ret) | |
1697 | return ret; | |
1698 | ||
1699 | /* User can pass only KPROBE_FLAG_DISABLED to register_kprobe */ | |
1700 | p->flags &= KPROBE_FLAG_DISABLED; | |
3516a460 | 1701 | p->nmissed = 0; |
9861668f | 1702 | INIT_LIST_HEAD(&p->list); |
afd66255 | 1703 | |
f7fa6ef0 MH |
1704 | ret = check_kprobe_address_safe(p, &probed_mod); |
1705 | if (ret) | |
1706 | return ret; | |
1707 | ||
1708 | mutex_lock(&kprobe_mutex); | |
afd66255 | 1709 | |
64f562c6 AM |
1710 | old_p = get_kprobe(p->addr); |
1711 | if (old_p) { | |
afd66255 | 1712 | /* Since this may unoptimize old_p, locking text_mutex. */ |
64f562c6 | 1713 | ret = register_aggr_kprobe(old_p, p); |
1da177e4 LT |
1714 | goto out; |
1715 | } | |
1da177e4 | 1716 | |
2d1e38f5 TG |
1717 | cpus_read_lock(); |
1718 | /* Prevent text modification */ | |
1719 | mutex_lock(&text_mutex); | |
ae6aa16f | 1720 | ret = prepare_kprobe(p); |
25764288 | 1721 | mutex_unlock(&text_mutex); |
2d1e38f5 | 1722 | cpus_read_unlock(); |
6f716acd | 1723 | if (ret) |
afd66255 | 1724 | goto out; |
49a2a1b8 | 1725 | |
64f562c6 | 1726 | INIT_HLIST_NODE(&p->hlist); |
3516a460 | 1727 | hlist_add_head_rcu(&p->hlist, |
1da177e4 LT |
1728 | &kprobe_table[hash_ptr(p->addr, KPROBE_HASH_BITS)]); |
1729 | ||
12310e34 JY |
1730 | if (!kprobes_all_disarmed && !kprobe_disabled(p)) { |
1731 | ret = arm_kprobe(p); | |
1732 | if (ret) { | |
1733 | hlist_del_rcu(&p->hlist); | |
ae8b7ce7 | 1734 | synchronize_rcu(); |
12310e34 JY |
1735 | goto out; |
1736 | } | |
1737 | } | |
afd66255 MH |
1738 | |
1739 | /* Try to optimize kprobe */ | |
1740 | try_to_optimize_kprobe(p); | |
1da177e4 | 1741 | out: |
7a7d1cf9 | 1742 | mutex_unlock(&kprobe_mutex); |
49a2a1b8 | 1743 | |
e8386a0c | 1744 | if (probed_mod) |
df019b1d | 1745 | module_put(probed_mod); |
e8386a0c | 1746 | |
1da177e4 LT |
1747 | return ret; |
1748 | } | |
99081ab5 | 1749 | EXPORT_SYMBOL_GPL(register_kprobe); |
1da177e4 | 1750 | |
6f0f1dd7 | 1751 | /* Check if all probes on the aggrprobe are disabled */ |
55479f64 | 1752 | static int aggr_kprobe_disabled(struct kprobe *ap) |
6f0f1dd7 MH |
1753 | { |
1754 | struct kprobe *kp; | |
1755 | ||
7e6a71d8 MH |
1756 | lockdep_assert_held(&kprobe_mutex); |
1757 | ||
1758 | list_for_each_entry(kp, &ap->list, list) | |
6f0f1dd7 MH |
1759 | if (!kprobe_disabled(kp)) |
1760 | /* | |
1761 | * There is an active probe on the list. | |
1762 | * We can't disable this ap. | |
1763 | */ | |
1764 | return 0; | |
1765 | ||
1766 | return 1; | |
1767 | } | |
1768 | ||
1769 | /* Disable one kprobe: Make sure called under kprobe_mutex is locked */ | |
55479f64 | 1770 | static struct kprobe *__disable_kprobe(struct kprobe *p) |
6f0f1dd7 MH |
1771 | { |
1772 | struct kprobe *orig_p; | |
297f9233 | 1773 | int ret; |
6f0f1dd7 MH |
1774 | |
1775 | /* Get an original kprobe for return */ | |
1776 | orig_p = __get_valid_kprobe(p); | |
1777 | if (unlikely(orig_p == NULL)) | |
297f9233 | 1778 | return ERR_PTR(-EINVAL); |
6f0f1dd7 MH |
1779 | |
1780 | if (!kprobe_disabled(p)) { | |
1781 | /* Disable probe if it is a child probe */ | |
1782 | if (p != orig_p) | |
1783 | p->flags |= KPROBE_FLAG_DISABLED; | |
1784 | ||
1785 | /* Try to disarm and disable this/parent probe */ | |
1786 | if (p == orig_p || aggr_kprobe_disabled(orig_p)) { | |
69d54b91 WN |
1787 | /* |
1788 | * If kprobes_all_disarmed is set, orig_p | |
1789 | * should have already been disarmed, so | |
1790 | * skip unneed disarming process. | |
1791 | */ | |
297f9233 JY |
1792 | if (!kprobes_all_disarmed) { |
1793 | ret = disarm_kprobe(orig_p, true); | |
1794 | if (ret) { | |
1795 | p->flags &= ~KPROBE_FLAG_DISABLED; | |
1796 | return ERR_PTR(ret); | |
1797 | } | |
1798 | } | |
6f0f1dd7 MH |
1799 | orig_p->flags |= KPROBE_FLAG_DISABLED; |
1800 | } | |
1801 | } | |
1802 | ||
1803 | return orig_p; | |
1804 | } | |
1805 | ||
de5bd88d MH |
1806 | /* |
1807 | * Unregister a kprobe without a scheduler synchronization. | |
1808 | */ | |
55479f64 | 1809 | static int __unregister_kprobe_top(struct kprobe *p) |
de5bd88d | 1810 | { |
6d8e40a8 | 1811 | struct kprobe *ap, *list_p; |
de5bd88d | 1812 | |
6f0f1dd7 MH |
1813 | /* Disable kprobe. This will disarm it if needed. */ |
1814 | ap = __disable_kprobe(p); | |
297f9233 JY |
1815 | if (IS_ERR(ap)) |
1816 | return PTR_ERR(ap); | |
de5bd88d | 1817 | |
6f0f1dd7 | 1818 | if (ap == p) |
bf8f6e5b | 1819 | /* |
6f0f1dd7 MH |
1820 | * This probe is an independent(and non-optimized) kprobe |
1821 | * (not an aggrprobe). Remove from the hash list. | |
bf8f6e5b | 1822 | */ |
6f0f1dd7 MH |
1823 | goto disarmed; |
1824 | ||
1825 | /* Following process expects this probe is an aggrprobe */ | |
1826 | WARN_ON(!kprobe_aggrprobe(ap)); | |
1827 | ||
6274de49 MH |
1828 | if (list_is_singular(&ap->list) && kprobe_disarmed(ap)) |
1829 | /* | |
1830 | * !disarmed could be happen if the probe is under delayed | |
1831 | * unoptimizing. | |
1832 | */ | |
6f0f1dd7 MH |
1833 | goto disarmed; |
1834 | else { | |
1835 | /* If disabling probe has special handlers, update aggrprobe */ | |
e8386a0c | 1836 | if (p->post_handler && !kprobe_gone(p)) { |
7e6a71d8 | 1837 | list_for_each_entry(list_p, &ap->list, list) { |
9861668f MH |
1838 | if ((list_p != p) && (list_p->post_handler)) |
1839 | goto noclean; | |
1840 | } | |
6d8e40a8 | 1841 | ap->post_handler = NULL; |
9861668f MH |
1842 | } |
1843 | noclean: | |
6f0f1dd7 MH |
1844 | /* |
1845 | * Remove from the aggrprobe: this path will do nothing in | |
1846 | * __unregister_kprobe_bottom(). | |
1847 | */ | |
49a2a1b8 | 1848 | list_del_rcu(&p->list); |
6f0f1dd7 MH |
1849 | if (!kprobe_disabled(ap) && !kprobes_all_disarmed) |
1850 | /* | |
1851 | * Try to optimize this probe again, because post | |
1852 | * handler may have been changed. | |
1853 | */ | |
1854 | optimize_kprobe(ap); | |
49a2a1b8 | 1855 | } |
9861668f | 1856 | return 0; |
6f0f1dd7 MH |
1857 | |
1858 | disarmed: | |
1859 | hlist_del_rcu(&ap->hlist); | |
1860 | return 0; | |
9861668f | 1861 | } |
3516a460 | 1862 | |
55479f64 | 1863 | static void __unregister_kprobe_bottom(struct kprobe *p) |
9861668f | 1864 | { |
6d8e40a8 | 1865 | struct kprobe *ap; |
b3e55c72 | 1866 | |
e8386a0c | 1867 | if (list_empty(&p->list)) |
6274de49 | 1868 | /* This is an independent kprobe */ |
0498b635 | 1869 | arch_remove_kprobe(p); |
e8386a0c | 1870 | else if (list_is_singular(&p->list)) { |
6274de49 | 1871 | /* This is the last child of an aggrprobe */ |
6d8e40a8 | 1872 | ap = list_entry(p->list.next, struct kprobe, list); |
e8386a0c | 1873 | list_del(&p->list); |
6d8e40a8 | 1874 | free_aggr_kprobe(ap); |
9861668f | 1875 | } |
6274de49 | 1876 | /* Otherwise, do nothing. */ |
9861668f MH |
1877 | } |
1878 | ||
55479f64 | 1879 | int register_kprobes(struct kprobe **kps, int num) |
9861668f MH |
1880 | { |
1881 | int i, ret = 0; | |
1882 | ||
1883 | if (num <= 0) | |
1884 | return -EINVAL; | |
1885 | for (i = 0; i < num; i++) { | |
49ad2fd7 | 1886 | ret = register_kprobe(kps[i]); |
67dddaad MH |
1887 | if (ret < 0) { |
1888 | if (i > 0) | |
1889 | unregister_kprobes(kps, i); | |
9861668f | 1890 | break; |
36721656 | 1891 | } |
49a2a1b8 | 1892 | } |
9861668f MH |
1893 | return ret; |
1894 | } | |
99081ab5 | 1895 | EXPORT_SYMBOL_GPL(register_kprobes); |
9861668f | 1896 | |
55479f64 | 1897 | void unregister_kprobe(struct kprobe *p) |
9861668f MH |
1898 | { |
1899 | unregister_kprobes(&p, 1); | |
1900 | } | |
99081ab5 | 1901 | EXPORT_SYMBOL_GPL(unregister_kprobe); |
9861668f | 1902 | |
55479f64 | 1903 | void unregister_kprobes(struct kprobe **kps, int num) |
9861668f MH |
1904 | { |
1905 | int i; | |
1906 | ||
1907 | if (num <= 0) | |
1908 | return; | |
1909 | mutex_lock(&kprobe_mutex); | |
1910 | for (i = 0; i < num; i++) | |
1911 | if (__unregister_kprobe_top(kps[i]) < 0) | |
1912 | kps[i]->addr = NULL; | |
1913 | mutex_unlock(&kprobe_mutex); | |
1914 | ||
ae8b7ce7 | 1915 | synchronize_rcu(); |
9861668f MH |
1916 | for (i = 0; i < num; i++) |
1917 | if (kps[i]->addr) | |
1918 | __unregister_kprobe_bottom(kps[i]); | |
1da177e4 | 1919 | } |
99081ab5 | 1920 | EXPORT_SYMBOL_GPL(unregister_kprobes); |
1da177e4 | 1921 | |
5f6bee34 NR |
1922 | int __weak kprobe_exceptions_notify(struct notifier_block *self, |
1923 | unsigned long val, void *data) | |
fc62d020 NR |
1924 | { |
1925 | return NOTIFY_DONE; | |
1926 | } | |
5f6bee34 | 1927 | NOKPROBE_SYMBOL(kprobe_exceptions_notify); |
fc62d020 | 1928 | |
1da177e4 | 1929 | static struct notifier_block kprobe_exceptions_nb = { |
3d5631e0 AK |
1930 | .notifier_call = kprobe_exceptions_notify, |
1931 | .priority = 0x7fffffff /* we need to be notified first */ | |
1932 | }; | |
1933 | ||
3d7e3382 ME |
1934 | unsigned long __weak arch_deref_entry_point(void *entry) |
1935 | { | |
1936 | return (unsigned long)entry; | |
1937 | } | |
1da177e4 | 1938 | |
9edddaa2 | 1939 | #ifdef CONFIG_KRETPROBES |
66ada2cc MH |
1940 | |
1941 | unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs, | |
1942 | void *trampoline_address, | |
1943 | void *frame_pointer) | |
1944 | { | |
1945 | struct kretprobe_instance *ri = NULL, *last = NULL; | |
b3388178 | 1946 | struct hlist_head *head; |
66ada2cc MH |
1947 | struct hlist_node *tmp; |
1948 | unsigned long flags; | |
1949 | kprobe_opcode_t *correct_ret_addr = NULL; | |
1950 | bool skipped = false; | |
1951 | ||
66ada2cc MH |
1952 | kretprobe_hash_lock(current, &head, &flags); |
1953 | ||
1954 | /* | |
1955 | * It is possible to have multiple instances associated with a given | |
1956 | * task either because multiple functions in the call path have | |
1957 | * return probes installed on them, and/or more than one | |
1958 | * return probe was registered for a target function. | |
1959 | * | |
1960 | * We can handle this because: | |
1961 | * - instances are always pushed into the head of the list | |
1962 | * - when multiple return probes are registered for the same | |
1963 | * function, the (chronologically) first instance's ret_addr | |
1964 | * will be the real return address, and all the rest will | |
1965 | * point to kretprobe_trampoline. | |
1966 | */ | |
1967 | hlist_for_each_entry(ri, head, hlist) { | |
1968 | if (ri->task != current) | |
1969 | /* another task is sharing our hash bucket */ | |
1970 | continue; | |
1971 | /* | |
1972 | * Return probes must be pushed on this hash list correct | |
1973 | * order (same as return order) so that it can be popped | |
1974 | * correctly. However, if we find it is pushed it incorrect | |
1975 | * order, this means we find a function which should not be | |
1976 | * probed, because the wrong order entry is pushed on the | |
1977 | * path of processing other kretprobe itself. | |
1978 | */ | |
1979 | if (ri->fp != frame_pointer) { | |
1980 | if (!skipped) | |
1981 | pr_warn("kretprobe is stacked incorrectly. Trying to fixup.\n"); | |
1982 | skipped = true; | |
1983 | continue; | |
1984 | } | |
1985 | ||
1986 | correct_ret_addr = ri->ret_addr; | |
1987 | if (skipped) | |
1988 | pr_warn("%ps must be blacklisted because of incorrect kretprobe order\n", | |
1989 | ri->rp->kp.addr); | |
1990 | ||
1991 | if (correct_ret_addr != trampoline_address) | |
1992 | /* | |
1993 | * This is the real return address. Any other | |
1994 | * instances associated with this task are for | |
1995 | * other calls deeper on the call stack | |
1996 | */ | |
1997 | break; | |
1998 | } | |
1999 | ||
319f0ce2 | 2000 | BUG_ON(!correct_ret_addr || (correct_ret_addr == trampoline_address)); |
66ada2cc MH |
2001 | last = ri; |
2002 | ||
2003 | hlist_for_each_entry_safe(ri, tmp, head, hlist) { | |
2004 | if (ri->task != current) | |
2005 | /* another task is sharing our hash bucket */ | |
2006 | continue; | |
2007 | if (ri->fp != frame_pointer) | |
2008 | continue; | |
2009 | ||
2010 | if (ri->rp && ri->rp->handler) { | |
2011 | struct kprobe *prev = kprobe_running(); | |
2012 | ||
2013 | __this_cpu_write(current_kprobe, &ri->rp->kp); | |
2014 | ri->ret_addr = correct_ret_addr; | |
2015 | ri->rp->handler(ri, regs); | |
2016 | __this_cpu_write(current_kprobe, prev); | |
2017 | } | |
2018 | ||
b3388178 | 2019 | recycle_rp_inst(ri); |
66ada2cc MH |
2020 | |
2021 | if (ri == last) | |
2022 | break; | |
2023 | } | |
2024 | ||
2025 | kretprobe_hash_unlock(current, &flags); | |
2026 | ||
66ada2cc MH |
2027 | return (unsigned long)correct_ret_addr; |
2028 | } | |
2029 | NOKPROBE_SYMBOL(__kretprobe_trampoline_handler) | |
2030 | ||
e65cefe8 AB |
2031 | /* |
2032 | * This kprobe pre_handler is registered with every kretprobe. When probe | |
2033 | * hits it will set up the return probe. | |
2034 | */ | |
820aede0 | 2035 | static int pre_handler_kretprobe(struct kprobe *p, struct pt_regs *regs) |
e65cefe8 AB |
2036 | { |
2037 | struct kretprobe *rp = container_of(p, struct kretprobe, kp); | |
ef53d9c5 S |
2038 | unsigned long hash, flags = 0; |
2039 | struct kretprobe_instance *ri; | |
e65cefe8 | 2040 | |
f96f5678 | 2041 | /* TODO: consider to only swap the RA after the last pre_handler fired */ |
ef53d9c5 | 2042 | hash = hash_ptr(current, KPROBE_HASH_BITS); |
645f224e SRV |
2043 | /* |
2044 | * Nested is a workaround that will soon not be needed. | |
2045 | * There's other protections that make sure the same lock | |
2046 | * is not taken on the same CPU that lockdep is unaware of. | |
2047 | */ | |
2048 | raw_spin_lock_irqsave_nested(&rp->lock, flags, 1); | |
4c4308cb | 2049 | if (!hlist_empty(&rp->free_instances)) { |
4c4308cb | 2050 | ri = hlist_entry(rp->free_instances.first, |
ef53d9c5 S |
2051 | struct kretprobe_instance, hlist); |
2052 | hlist_del(&ri->hlist); | |
ec484608 | 2053 | raw_spin_unlock_irqrestore(&rp->lock, flags); |
ef53d9c5 | 2054 | |
4c4308cb CH |
2055 | ri->rp = rp; |
2056 | ri->task = current; | |
f47cd9b5 | 2057 | |
55ca6140 | 2058 | if (rp->entry_handler && rp->entry_handler(ri, regs)) { |
645f224e | 2059 | raw_spin_lock_irqsave_nested(&rp->lock, flags, 1); |
55ca6140 JL |
2060 | hlist_add_head(&ri->hlist, &rp->free_instances); |
2061 | raw_spin_unlock_irqrestore(&rp->lock, flags); | |
f47cd9b5 | 2062 | return 0; |
55ca6140 | 2063 | } |
f47cd9b5 | 2064 | |
4c4308cb CH |
2065 | arch_prepare_kretprobe(ri, regs); |
2066 | ||
2067 | /* XXX(hch): why is there no hlist_move_head? */ | |
ef53d9c5 S |
2068 | INIT_HLIST_NODE(&ri->hlist); |
2069 | kretprobe_table_lock(hash, &flags); | |
2070 | hlist_add_head(&ri->hlist, &kretprobe_inst_table[hash]); | |
2071 | kretprobe_table_unlock(hash, &flags); | |
2072 | } else { | |
4c4308cb | 2073 | rp->nmissed++; |
ec484608 | 2074 | raw_spin_unlock_irqrestore(&rp->lock, flags); |
ef53d9c5 | 2075 | } |
e65cefe8 AB |
2076 | return 0; |
2077 | } | |
820aede0 | 2078 | NOKPROBE_SYMBOL(pre_handler_kretprobe); |
e65cefe8 | 2079 | |
659b957f | 2080 | bool __weak arch_kprobe_on_func_entry(unsigned long offset) |
90ec5e89 NR |
2081 | { |
2082 | return !offset; | |
2083 | } | |
2084 | ||
659b957f | 2085 | bool kprobe_on_func_entry(kprobe_opcode_t *addr, const char *sym, unsigned long offset) |
1d585e70 NR |
2086 | { |
2087 | kprobe_opcode_t *kp_addr = _kprobe_addr(addr, sym, offset); | |
2088 | ||
2089 | if (IS_ERR(kp_addr)) | |
2090 | return false; | |
2091 | ||
2092 | if (!kallsyms_lookup_size_offset((unsigned long)kp_addr, NULL, &offset) || | |
659b957f | 2093 | !arch_kprobe_on_func_entry(offset)) |
1d585e70 NR |
2094 | return false; |
2095 | ||
2096 | return true; | |
2097 | } | |
2098 | ||
55479f64 | 2099 | int register_kretprobe(struct kretprobe *rp) |
b94cce92 HN |
2100 | { |
2101 | int ret = 0; | |
2102 | struct kretprobe_instance *inst; | |
2103 | int i; | |
b2a5cd69 | 2104 | void *addr; |
90ec5e89 | 2105 | |
659b957f | 2106 | if (!kprobe_on_func_entry(rp->kp.addr, rp->kp.symbol_name, rp->kp.offset)) |
90ec5e89 | 2107 | return -EINVAL; |
f438d914 MH |
2108 | |
2109 | if (kretprobe_blacklist_size) { | |
b2a5cd69 | 2110 | addr = kprobe_addr(&rp->kp); |
bc81d48d MH |
2111 | if (IS_ERR(addr)) |
2112 | return PTR_ERR(addr); | |
f438d914 MH |
2113 | |
2114 | for (i = 0; kretprobe_blacklist[i].name != NULL; i++) { | |
2115 | if (kretprobe_blacklist[i].addr == addr) | |
2116 | return -EINVAL; | |
2117 | } | |
2118 | } | |
b94cce92 HN |
2119 | |
2120 | rp->kp.pre_handler = pre_handler_kretprobe; | |
7522a842 AM |
2121 | rp->kp.post_handler = NULL; |
2122 | rp->kp.fault_handler = NULL; | |
b94cce92 HN |
2123 | |
2124 | /* Pre-allocate memory for max kretprobe instances */ | |
2125 | if (rp->maxactive <= 0) { | |
92616606 | 2126 | #ifdef CONFIG_PREEMPTION |
c2ef6661 | 2127 | rp->maxactive = max_t(unsigned int, 10, 2*num_possible_cpus()); |
b94cce92 | 2128 | #else |
4dae560f | 2129 | rp->maxactive = num_possible_cpus(); |
b94cce92 HN |
2130 | #endif |
2131 | } | |
ec484608 | 2132 | raw_spin_lock_init(&rp->lock); |
b94cce92 HN |
2133 | INIT_HLIST_HEAD(&rp->free_instances); |
2134 | for (i = 0; i < rp->maxactive; i++) { | |
f47cd9b5 AS |
2135 | inst = kmalloc(sizeof(struct kretprobe_instance) + |
2136 | rp->data_size, GFP_KERNEL); | |
b94cce92 HN |
2137 | if (inst == NULL) { |
2138 | free_rp_inst(rp); | |
2139 | return -ENOMEM; | |
2140 | } | |
ef53d9c5 S |
2141 | INIT_HLIST_NODE(&inst->hlist); |
2142 | hlist_add_head(&inst->hlist, &rp->free_instances); | |
b94cce92 HN |
2143 | } |
2144 | ||
2145 | rp->nmissed = 0; | |
2146 | /* Establish function entry probe point */ | |
49ad2fd7 | 2147 | ret = register_kprobe(&rp->kp); |
4a296e07 | 2148 | if (ret != 0) |
b94cce92 HN |
2149 | free_rp_inst(rp); |
2150 | return ret; | |
2151 | } | |
99081ab5 | 2152 | EXPORT_SYMBOL_GPL(register_kretprobe); |
b94cce92 | 2153 | |
55479f64 | 2154 | int register_kretprobes(struct kretprobe **rps, int num) |
4a296e07 MH |
2155 | { |
2156 | int ret = 0, i; | |
2157 | ||
2158 | if (num <= 0) | |
2159 | return -EINVAL; | |
2160 | for (i = 0; i < num; i++) { | |
49ad2fd7 | 2161 | ret = register_kretprobe(rps[i]); |
67dddaad MH |
2162 | if (ret < 0) { |
2163 | if (i > 0) | |
2164 | unregister_kretprobes(rps, i); | |
4a296e07 MH |
2165 | break; |
2166 | } | |
2167 | } | |
2168 | return ret; | |
2169 | } | |
99081ab5 | 2170 | EXPORT_SYMBOL_GPL(register_kretprobes); |
4a296e07 | 2171 | |
55479f64 | 2172 | void unregister_kretprobe(struct kretprobe *rp) |
4a296e07 MH |
2173 | { |
2174 | unregister_kretprobes(&rp, 1); | |
2175 | } | |
99081ab5 | 2176 | EXPORT_SYMBOL_GPL(unregister_kretprobe); |
4a296e07 | 2177 | |
55479f64 | 2178 | void unregister_kretprobes(struct kretprobe **rps, int num) |
4a296e07 MH |
2179 | { |
2180 | int i; | |
2181 | ||
2182 | if (num <= 0) | |
2183 | return; | |
2184 | mutex_lock(&kprobe_mutex); | |
2185 | for (i = 0; i < num; i++) | |
2186 | if (__unregister_kprobe_top(&rps[i]->kp) < 0) | |
2187 | rps[i]->kp.addr = NULL; | |
2188 | mutex_unlock(&kprobe_mutex); | |
2189 | ||
ae8b7ce7 | 2190 | synchronize_rcu(); |
4a296e07 MH |
2191 | for (i = 0; i < num; i++) { |
2192 | if (rps[i]->kp.addr) { | |
2193 | __unregister_kprobe_bottom(&rps[i]->kp); | |
2194 | cleanup_rp_inst(rps[i]); | |
2195 | } | |
2196 | } | |
2197 | } | |
99081ab5 | 2198 | EXPORT_SYMBOL_GPL(unregister_kretprobes); |
4a296e07 | 2199 | |
9edddaa2 | 2200 | #else /* CONFIG_KRETPROBES */ |
55479f64 | 2201 | int register_kretprobe(struct kretprobe *rp) |
b94cce92 HN |
2202 | { |
2203 | return -ENOSYS; | |
2204 | } | |
99081ab5 | 2205 | EXPORT_SYMBOL_GPL(register_kretprobe); |
b94cce92 | 2206 | |
55479f64 | 2207 | int register_kretprobes(struct kretprobe **rps, int num) |
346fd59b | 2208 | { |
4a296e07 | 2209 | return -ENOSYS; |
346fd59b | 2210 | } |
99081ab5 MH |
2211 | EXPORT_SYMBOL_GPL(register_kretprobes); |
2212 | ||
55479f64 | 2213 | void unregister_kretprobe(struct kretprobe *rp) |
b94cce92 | 2214 | { |
4a296e07 | 2215 | } |
99081ab5 | 2216 | EXPORT_SYMBOL_GPL(unregister_kretprobe); |
b94cce92 | 2217 | |
55479f64 | 2218 | void unregister_kretprobes(struct kretprobe **rps, int num) |
4a296e07 MH |
2219 | { |
2220 | } | |
99081ab5 | 2221 | EXPORT_SYMBOL_GPL(unregister_kretprobes); |
4c4308cb | 2222 | |
820aede0 | 2223 | static int pre_handler_kretprobe(struct kprobe *p, struct pt_regs *regs) |
4a296e07 MH |
2224 | { |
2225 | return 0; | |
b94cce92 | 2226 | } |
820aede0 | 2227 | NOKPROBE_SYMBOL(pre_handler_kretprobe); |
b94cce92 | 2228 | |
4a296e07 MH |
2229 | #endif /* CONFIG_KRETPROBES */ |
2230 | ||
e8386a0c | 2231 | /* Set the kprobe gone and remove its instruction buffer. */ |
55479f64 | 2232 | static void kill_kprobe(struct kprobe *p) |
e8386a0c MH |
2233 | { |
2234 | struct kprobe *kp; | |
de5bd88d | 2235 | |
7e6a71d8 MH |
2236 | lockdep_assert_held(&kprobe_mutex); |
2237 | ||
b0399092 MS |
2238 | if (WARN_ON_ONCE(kprobe_gone(p))) |
2239 | return; | |
2240 | ||
e8386a0c | 2241 | p->flags |= KPROBE_FLAG_GONE; |
afd66255 | 2242 | if (kprobe_aggrprobe(p)) { |
e8386a0c MH |
2243 | /* |
2244 | * If this is an aggr_kprobe, we have to list all the | |
2245 | * chained probes and mark them GONE. | |
2246 | */ | |
7e6a71d8 | 2247 | list_for_each_entry(kp, &p->list, list) |
e8386a0c MH |
2248 | kp->flags |= KPROBE_FLAG_GONE; |
2249 | p->post_handler = NULL; | |
afd66255 | 2250 | kill_optimized_kprobe(p); |
e8386a0c MH |
2251 | } |
2252 | /* | |
2253 | * Here, we can remove insn_slot safely, because no thread calls | |
2254 | * the original probed function (which will be freed soon) any more. | |
2255 | */ | |
2256 | arch_remove_kprobe(p); | |
0cb2f137 MS |
2257 | |
2258 | /* | |
2259 | * The module is going away. We should disarm the kprobe which | |
3031313e MH |
2260 | * is using ftrace, because ftrace framework is still available at |
2261 | * MODULE_STATE_GOING notification. | |
0cb2f137 | 2262 | */ |
3031313e | 2263 | if (kprobe_ftrace(p) && !kprobe_disabled(p) && !kprobes_all_disarmed) |
0cb2f137 | 2264 | disarm_kprobe_ftrace(p); |
e8386a0c MH |
2265 | } |
2266 | ||
c0614829 | 2267 | /* Disable one kprobe */ |
55479f64 | 2268 | int disable_kprobe(struct kprobe *kp) |
c0614829 MH |
2269 | { |
2270 | int ret = 0; | |
297f9233 | 2271 | struct kprobe *p; |
c0614829 MH |
2272 | |
2273 | mutex_lock(&kprobe_mutex); | |
2274 | ||
6f0f1dd7 | 2275 | /* Disable this kprobe */ |
297f9233 JY |
2276 | p = __disable_kprobe(kp); |
2277 | if (IS_ERR(p)) | |
2278 | ret = PTR_ERR(p); | |
c0614829 | 2279 | |
c0614829 MH |
2280 | mutex_unlock(&kprobe_mutex); |
2281 | return ret; | |
2282 | } | |
2283 | EXPORT_SYMBOL_GPL(disable_kprobe); | |
2284 | ||
2285 | /* Enable one kprobe */ | |
55479f64 | 2286 | int enable_kprobe(struct kprobe *kp) |
c0614829 MH |
2287 | { |
2288 | int ret = 0; | |
2289 | struct kprobe *p; | |
2290 | ||
2291 | mutex_lock(&kprobe_mutex); | |
2292 | ||
2293 | /* Check whether specified probe is valid. */ | |
2294 | p = __get_valid_kprobe(kp); | |
2295 | if (unlikely(p == NULL)) { | |
2296 | ret = -EINVAL; | |
2297 | goto out; | |
2298 | } | |
2299 | ||
2300 | if (kprobe_gone(kp)) { | |
2301 | /* This kprobe has gone, we couldn't enable it. */ | |
2302 | ret = -EINVAL; | |
2303 | goto out; | |
2304 | } | |
2305 | ||
2306 | if (p != kp) | |
2307 | kp->flags &= ~KPROBE_FLAG_DISABLED; | |
2308 | ||
2309 | if (!kprobes_all_disarmed && kprobe_disabled(p)) { | |
2310 | p->flags &= ~KPROBE_FLAG_DISABLED; | |
12310e34 JY |
2311 | ret = arm_kprobe(p); |
2312 | if (ret) | |
2313 | p->flags |= KPROBE_FLAG_DISABLED; | |
c0614829 MH |
2314 | } |
2315 | out: | |
2316 | mutex_unlock(&kprobe_mutex); | |
2317 | return ret; | |
2318 | } | |
2319 | EXPORT_SYMBOL_GPL(enable_kprobe); | |
2320 | ||
4458515b | 2321 | /* Caller must NOT call this in usual path. This is only for critical case */ |
820aede0 | 2322 | void dump_kprobe(struct kprobe *kp) |
24851d24 | 2323 | { |
4458515b MH |
2324 | pr_err("Dumping kprobe:\n"); |
2325 | pr_err("Name: %s\nOffset: %x\nAddress: %pS\n", | |
2326 | kp->symbol_name, kp->offset, kp->addr); | |
24851d24 | 2327 | } |
820aede0 | 2328 | NOKPROBE_SYMBOL(dump_kprobe); |
24851d24 | 2329 | |
fb1a59fa MH |
2330 | int kprobe_add_ksym_blacklist(unsigned long entry) |
2331 | { | |
2332 | struct kprobe_blacklist_entry *ent; | |
2333 | unsigned long offset = 0, size = 0; | |
2334 | ||
2335 | if (!kernel_text_address(entry) || | |
2336 | !kallsyms_lookup_size_offset(entry, &size, &offset)) | |
2337 | return -EINVAL; | |
2338 | ||
2339 | ent = kmalloc(sizeof(*ent), GFP_KERNEL); | |
2340 | if (!ent) | |
2341 | return -ENOMEM; | |
2342 | ent->start_addr = entry; | |
2343 | ent->end_addr = entry + size; | |
2344 | INIT_LIST_HEAD(&ent->list); | |
2345 | list_add_tail(&ent->list, &kprobe_blacklist); | |
2346 | ||
2347 | return (int)size; | |
2348 | } | |
2349 | ||
2350 | /* Add all symbols in given area into kprobe blacklist */ | |
2351 | int kprobe_add_area_blacklist(unsigned long start, unsigned long end) | |
2352 | { | |
2353 | unsigned long entry; | |
2354 | int ret = 0; | |
2355 | ||
2356 | for (entry = start; entry < end; entry += ret) { | |
2357 | ret = kprobe_add_ksym_blacklist(entry); | |
2358 | if (ret < 0) | |
2359 | return ret; | |
2360 | if (ret == 0) /* In case of alias symbol */ | |
2361 | ret = 1; | |
2362 | } | |
2363 | return 0; | |
2364 | } | |
2365 | ||
1e6769b0 MH |
2366 | /* Remove all symbols in given area from kprobe blacklist */ |
2367 | static void kprobe_remove_area_blacklist(unsigned long start, unsigned long end) | |
2368 | { | |
2369 | struct kprobe_blacklist_entry *ent, *n; | |
2370 | ||
2371 | list_for_each_entry_safe(ent, n, &kprobe_blacklist, list) { | |
2372 | if (ent->start_addr < start || ent->start_addr >= end) | |
2373 | continue; | |
2374 | list_del(&ent->list); | |
2375 | kfree(ent); | |
2376 | } | |
2377 | } | |
2378 | ||
16db6264 MH |
2379 | static void kprobe_remove_ksym_blacklist(unsigned long entry) |
2380 | { | |
2381 | kprobe_remove_area_blacklist(entry, entry + 1); | |
2382 | } | |
2383 | ||
d002b8bc AH |
2384 | int __weak arch_kprobe_get_kallsym(unsigned int *symnum, unsigned long *value, |
2385 | char *type, char *sym) | |
2386 | { | |
2387 | return -ERANGE; | |
2388 | } | |
2389 | ||
2390 | int kprobe_get_kallsym(unsigned int symnum, unsigned long *value, char *type, | |
2391 | char *sym) | |
2392 | { | |
2393 | #ifdef __ARCH_WANT_KPROBES_INSN_SLOT | |
2394 | if (!kprobe_cache_get_kallsym(&kprobe_insn_slots, &symnum, value, type, sym)) | |
2395 | return 0; | |
2396 | #ifdef CONFIG_OPTPROBES | |
2397 | if (!kprobe_cache_get_kallsym(&kprobe_optinsn_slots, &symnum, value, type, sym)) | |
2398 | return 0; | |
2399 | #endif | |
2400 | #endif | |
2401 | if (!arch_kprobe_get_kallsym(&symnum, value, type, sym)) | |
2402 | return 0; | |
2403 | return -ERANGE; | |
2404 | } | |
2405 | ||
fb1a59fa MH |
2406 | int __init __weak arch_populate_kprobe_blacklist(void) |
2407 | { | |
2408 | return 0; | |
2409 | } | |
2410 | ||
376e2424 MH |
2411 | /* |
2412 | * Lookup and populate the kprobe_blacklist. | |
2413 | * | |
2414 | * Unlike the kretprobe blacklist, we'll need to determine | |
2415 | * the range of addresses that belong to the said functions, | |
2416 | * since a kprobe need not necessarily be at the beginning | |
2417 | * of a function. | |
2418 | */ | |
2419 | static int __init populate_kprobe_blacklist(unsigned long *start, | |
2420 | unsigned long *end) | |
2421 | { | |
fb1a59fa | 2422 | unsigned long entry; |
376e2424 | 2423 | unsigned long *iter; |
fb1a59fa | 2424 | int ret; |
376e2424 MH |
2425 | |
2426 | for (iter = start; iter < end; iter++) { | |
d81b4253 | 2427 | entry = arch_deref_entry_point((void *)*iter); |
fb1a59fa MH |
2428 | ret = kprobe_add_ksym_blacklist(entry); |
2429 | if (ret == -EINVAL) | |
376e2424 | 2430 | continue; |
fb1a59fa MH |
2431 | if (ret < 0) |
2432 | return ret; | |
376e2424 | 2433 | } |
fb1a59fa MH |
2434 | |
2435 | /* Symbols in __kprobes_text are blacklisted */ | |
2436 | ret = kprobe_add_area_blacklist((unsigned long)__kprobes_text_start, | |
2437 | (unsigned long)__kprobes_text_end); | |
66e9b071 TG |
2438 | if (ret) |
2439 | return ret; | |
2440 | ||
2441 | /* Symbols in noinstr section are blacklisted */ | |
2442 | ret = kprobe_add_area_blacklist((unsigned long)__noinstr_text_start, | |
2443 | (unsigned long)__noinstr_text_end); | |
fb1a59fa MH |
2444 | |
2445 | return ret ? : arch_populate_kprobe_blacklist(); | |
376e2424 MH |
2446 | } |
2447 | ||
1e6769b0 MH |
2448 | static void add_module_kprobe_blacklist(struct module *mod) |
2449 | { | |
2450 | unsigned long start, end; | |
16db6264 MH |
2451 | int i; |
2452 | ||
2453 | if (mod->kprobe_blacklist) { | |
2454 | for (i = 0; i < mod->num_kprobe_blacklist; i++) | |
2455 | kprobe_add_ksym_blacklist(mod->kprobe_blacklist[i]); | |
2456 | } | |
1e6769b0 MH |
2457 | |
2458 | start = (unsigned long)mod->kprobes_text_start; | |
2459 | if (start) { | |
2460 | end = start + mod->kprobes_text_size; | |
2461 | kprobe_add_area_blacklist(start, end); | |
2462 | } | |
66e9b071 TG |
2463 | |
2464 | start = (unsigned long)mod->noinstr_text_start; | |
2465 | if (start) { | |
2466 | end = start + mod->noinstr_text_size; | |
2467 | kprobe_add_area_blacklist(start, end); | |
2468 | } | |
1e6769b0 MH |
2469 | } |
2470 | ||
2471 | static void remove_module_kprobe_blacklist(struct module *mod) | |
2472 | { | |
2473 | unsigned long start, end; | |
16db6264 MH |
2474 | int i; |
2475 | ||
2476 | if (mod->kprobe_blacklist) { | |
2477 | for (i = 0; i < mod->num_kprobe_blacklist; i++) | |
2478 | kprobe_remove_ksym_blacklist(mod->kprobe_blacklist[i]); | |
2479 | } | |
1e6769b0 MH |
2480 | |
2481 | start = (unsigned long)mod->kprobes_text_start; | |
2482 | if (start) { | |
2483 | end = start + mod->kprobes_text_size; | |
2484 | kprobe_remove_area_blacklist(start, end); | |
2485 | } | |
66e9b071 TG |
2486 | |
2487 | start = (unsigned long)mod->noinstr_text_start; | |
2488 | if (start) { | |
2489 | end = start + mod->noinstr_text_size; | |
2490 | kprobe_remove_area_blacklist(start, end); | |
2491 | } | |
1e6769b0 MH |
2492 | } |
2493 | ||
e8386a0c | 2494 | /* Module notifier call back, checking kprobes on the module */ |
55479f64 MH |
2495 | static int kprobes_module_callback(struct notifier_block *nb, |
2496 | unsigned long val, void *data) | |
e8386a0c MH |
2497 | { |
2498 | struct module *mod = data; | |
2499 | struct hlist_head *head; | |
e8386a0c MH |
2500 | struct kprobe *p; |
2501 | unsigned int i; | |
f24659d9 | 2502 | int checkcore = (val == MODULE_STATE_GOING); |
e8386a0c | 2503 | |
1e6769b0 MH |
2504 | if (val == MODULE_STATE_COMING) { |
2505 | mutex_lock(&kprobe_mutex); | |
2506 | add_module_kprobe_blacklist(mod); | |
2507 | mutex_unlock(&kprobe_mutex); | |
2508 | } | |
f24659d9 | 2509 | if (val != MODULE_STATE_GOING && val != MODULE_STATE_LIVE) |
e8386a0c MH |
2510 | return NOTIFY_DONE; |
2511 | ||
2512 | /* | |
f24659d9 MH |
2513 | * When MODULE_STATE_GOING was notified, both of module .text and |
2514 | * .init.text sections would be freed. When MODULE_STATE_LIVE was | |
2515 | * notified, only .init.text section would be freed. We need to | |
2516 | * disable kprobes which have been inserted in the sections. | |
e8386a0c MH |
2517 | */ |
2518 | mutex_lock(&kprobe_mutex); | |
2519 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { | |
2520 | head = &kprobe_table[i]; | |
b0399092 MS |
2521 | hlist_for_each_entry(p, head, hlist) { |
2522 | if (kprobe_gone(p)) | |
2523 | continue; | |
2524 | ||
f24659d9 MH |
2525 | if (within_module_init((unsigned long)p->addr, mod) || |
2526 | (checkcore && | |
2527 | within_module_core((unsigned long)p->addr, mod))) { | |
e8386a0c MH |
2528 | /* |
2529 | * The vaddr this probe is installed will soon | |
2530 | * be vfreed buy not synced to disk. Hence, | |
2531 | * disarming the breakpoint isn't needed. | |
545a0281 SRV |
2532 | * |
2533 | * Note, this will also move any optimized probes | |
2534 | * that are pending to be removed from their | |
2535 | * corresponding lists to the freeing_list and | |
2536 | * will not be touched by the delayed | |
2537 | * kprobe_optimizer work handler. | |
e8386a0c MH |
2538 | */ |
2539 | kill_kprobe(p); | |
2540 | } | |
b0399092 | 2541 | } |
e8386a0c | 2542 | } |
1e6769b0 MH |
2543 | if (val == MODULE_STATE_GOING) |
2544 | remove_module_kprobe_blacklist(mod); | |
e8386a0c MH |
2545 | mutex_unlock(&kprobe_mutex); |
2546 | return NOTIFY_DONE; | |
2547 | } | |
2548 | ||
2549 | static struct notifier_block kprobe_module_nb = { | |
2550 | .notifier_call = kprobes_module_callback, | |
2551 | .priority = 0 | |
2552 | }; | |
2553 | ||
376e2424 MH |
2554 | /* Markers of _kprobe_blacklist section */ |
2555 | extern unsigned long __start_kprobe_blacklist[]; | |
2556 | extern unsigned long __stop_kprobe_blacklist[]; | |
2557 | ||
82d083ab MH |
2558 | void kprobe_free_init_mem(void) |
2559 | { | |
2560 | void *start = (void *)(&__init_begin); | |
2561 | void *end = (void *)(&__init_end); | |
2562 | struct hlist_head *head; | |
2563 | struct kprobe *p; | |
2564 | int i; | |
2565 | ||
2566 | mutex_lock(&kprobe_mutex); | |
2567 | ||
2568 | /* Kill all kprobes on initmem */ | |
2569 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { | |
2570 | head = &kprobe_table[i]; | |
2571 | hlist_for_each_entry(p, head, hlist) { | |
2572 | if (start <= (void *)p->addr && (void *)p->addr < end) | |
2573 | kill_kprobe(p); | |
2574 | } | |
2575 | } | |
2576 | ||
2577 | mutex_unlock(&kprobe_mutex); | |
2578 | } | |
2579 | ||
1da177e4 LT |
2580 | static int __init init_kprobes(void) |
2581 | { | |
2582 | int i, err = 0; | |
2583 | ||
2584 | /* FIXME allocate the probe table, currently defined statically */ | |
2585 | /* initialize all list heads */ | |
b94cce92 | 2586 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
1da177e4 | 2587 | INIT_HLIST_HEAD(&kprobe_table[i]); |
b94cce92 | 2588 | INIT_HLIST_HEAD(&kretprobe_inst_table[i]); |
ec484608 | 2589 | raw_spin_lock_init(&(kretprobe_table_locks[i].lock)); |
b94cce92 | 2590 | } |
1da177e4 | 2591 | |
376e2424 MH |
2592 | err = populate_kprobe_blacklist(__start_kprobe_blacklist, |
2593 | __stop_kprobe_blacklist); | |
2594 | if (err) { | |
2595 | pr_err("kprobes: failed to populate blacklist: %d\n", err); | |
2596 | pr_err("Please take care of using kprobes.\n"); | |
3d8d996e SD |
2597 | } |
2598 | ||
f438d914 MH |
2599 | if (kretprobe_blacklist_size) { |
2600 | /* lookup the function address from its name */ | |
2601 | for (i = 0; kretprobe_blacklist[i].name != NULL; i++) { | |
49e0b465 | 2602 | kretprobe_blacklist[i].addr = |
290e3070 | 2603 | kprobe_lookup_name(kretprobe_blacklist[i].name, 0); |
f438d914 MH |
2604 | if (!kretprobe_blacklist[i].addr) |
2605 | printk("kretprobe: lookup failed: %s\n", | |
2606 | kretprobe_blacklist[i].name); | |
2607 | } | |
2608 | } | |
2609 | ||
b2be84df MH |
2610 | #if defined(CONFIG_OPTPROBES) |
2611 | #if defined(__ARCH_WANT_KPROBES_INSN_SLOT) | |
afd66255 MH |
2612 | /* Init kprobe_optinsn_slots */ |
2613 | kprobe_optinsn_slots.insn_size = MAX_OPTINSN_SIZE; | |
2614 | #endif | |
b2be84df MH |
2615 | /* By default, kprobes can be optimized */ |
2616 | kprobes_allow_optimization = true; | |
2617 | #endif | |
afd66255 | 2618 | |
e579abeb MH |
2619 | /* By default, kprobes are armed */ |
2620 | kprobes_all_disarmed = false; | |
bf8f6e5b | 2621 | |
6772926b | 2622 | err = arch_init_kprobes(); |
802eae7c RL |
2623 | if (!err) |
2624 | err = register_die_notifier(&kprobe_exceptions_nb); | |
e8386a0c MH |
2625 | if (!err) |
2626 | err = register_module_notifier(&kprobe_module_nb); | |
2627 | ||
ef53d9c5 | 2628 | kprobes_initialized = (err == 0); |
802eae7c | 2629 | |
8c1c9356 AM |
2630 | if (!err) |
2631 | init_test_probes(); | |
1da177e4 LT |
2632 | return err; |
2633 | } | |
36dadef2 | 2634 | early_initcall(init_kprobes); |
1da177e4 | 2635 | |
346fd59b | 2636 | #ifdef CONFIG_DEBUG_FS |
55479f64 | 2637 | static void report_probe(struct seq_file *pi, struct kprobe *p, |
afd66255 | 2638 | const char *sym, int offset, char *modname, struct kprobe *pp) |
346fd59b SD |
2639 | { |
2640 | char *kprobe_type; | |
81365a94 | 2641 | void *addr = p->addr; |
346fd59b SD |
2642 | |
2643 | if (p->pre_handler == pre_handler_kretprobe) | |
2644 | kprobe_type = "r"; | |
346fd59b SD |
2645 | else |
2646 | kprobe_type = "k"; | |
afd66255 | 2647 | |
60f7bb66 | 2648 | if (!kallsyms_show_value(pi->file->f_cred)) |
81365a94 MH |
2649 | addr = NULL; |
2650 | ||
346fd59b | 2651 | if (sym) |
81365a94 MH |
2652 | seq_printf(pi, "%px %s %s+0x%x %s ", |
2653 | addr, kprobe_type, sym, offset, | |
afd66255 | 2654 | (modname ? modname : " ")); |
81365a94 MH |
2655 | else /* try to use %pS */ |
2656 | seq_printf(pi, "%px %s %pS ", | |
2657 | addr, kprobe_type, p->addr); | |
afd66255 MH |
2658 | |
2659 | if (!pp) | |
2660 | pp = p; | |
ae6aa16f | 2661 | seq_printf(pi, "%s%s%s%s\n", |
afd66255 MH |
2662 | (kprobe_gone(p) ? "[GONE]" : ""), |
2663 | ((kprobe_disabled(p) && !kprobe_gone(p)) ? "[DISABLED]" : ""), | |
ae6aa16f MH |
2664 | (kprobe_optimized(pp) ? "[OPTIMIZED]" : ""), |
2665 | (kprobe_ftrace(pp) ? "[FTRACE]" : "")); | |
346fd59b SD |
2666 | } |
2667 | ||
55479f64 | 2668 | static void *kprobe_seq_start(struct seq_file *f, loff_t *pos) |
346fd59b SD |
2669 | { |
2670 | return (*pos < KPROBE_TABLE_SIZE) ? pos : NULL; | |
2671 | } | |
2672 | ||
55479f64 | 2673 | static void *kprobe_seq_next(struct seq_file *f, void *v, loff_t *pos) |
346fd59b SD |
2674 | { |
2675 | (*pos)++; | |
2676 | if (*pos >= KPROBE_TABLE_SIZE) | |
2677 | return NULL; | |
2678 | return pos; | |
2679 | } | |
2680 | ||
55479f64 | 2681 | static void kprobe_seq_stop(struct seq_file *f, void *v) |
346fd59b SD |
2682 | { |
2683 | /* Nothing to do */ | |
2684 | } | |
2685 | ||
55479f64 | 2686 | static int show_kprobe_addr(struct seq_file *pi, void *v) |
346fd59b SD |
2687 | { |
2688 | struct hlist_head *head; | |
346fd59b SD |
2689 | struct kprobe *p, *kp; |
2690 | const char *sym = NULL; | |
2691 | unsigned int i = *(loff_t *) v; | |
ffb45122 | 2692 | unsigned long offset = 0; |
ab767865 | 2693 | char *modname, namebuf[KSYM_NAME_LEN]; |
346fd59b SD |
2694 | |
2695 | head = &kprobe_table[i]; | |
2696 | preempt_disable(); | |
b67bfe0d | 2697 | hlist_for_each_entry_rcu(p, head, hlist) { |
ffb45122 | 2698 | sym = kallsyms_lookup((unsigned long)p->addr, NULL, |
346fd59b | 2699 | &offset, &modname, namebuf); |
afd66255 | 2700 | if (kprobe_aggrprobe(p)) { |
346fd59b | 2701 | list_for_each_entry_rcu(kp, &p->list, list) |
afd66255 | 2702 | report_probe(pi, kp, sym, offset, modname, p); |
346fd59b | 2703 | } else |
afd66255 | 2704 | report_probe(pi, p, sym, offset, modname, NULL); |
346fd59b SD |
2705 | } |
2706 | preempt_enable(); | |
2707 | return 0; | |
2708 | } | |
2709 | ||
eac2cece | 2710 | static const struct seq_operations kprobes_sops = { |
346fd59b SD |
2711 | .start = kprobe_seq_start, |
2712 | .next = kprobe_seq_next, | |
2713 | .stop = kprobe_seq_stop, | |
2714 | .show = show_kprobe_addr | |
2715 | }; | |
2716 | ||
eac2cece | 2717 | DEFINE_SEQ_ATTRIBUTE(kprobes); |
346fd59b | 2718 | |
63724740 MH |
2719 | /* kprobes/blacklist -- shows which functions can not be probed */ |
2720 | static void *kprobe_blacklist_seq_start(struct seq_file *m, loff_t *pos) | |
2721 | { | |
4fdd8887 | 2722 | mutex_lock(&kprobe_mutex); |
63724740 MH |
2723 | return seq_list_start(&kprobe_blacklist, *pos); |
2724 | } | |
2725 | ||
2726 | static void *kprobe_blacklist_seq_next(struct seq_file *m, void *v, loff_t *pos) | |
2727 | { | |
2728 | return seq_list_next(v, &kprobe_blacklist, pos); | |
2729 | } | |
2730 | ||
2731 | static int kprobe_blacklist_seq_show(struct seq_file *m, void *v) | |
2732 | { | |
2733 | struct kprobe_blacklist_entry *ent = | |
2734 | list_entry(v, struct kprobe_blacklist_entry, list); | |
2735 | ||
ffb9bd68 MH |
2736 | /* |
2737 | * If /proc/kallsyms is not showing kernel address, we won't | |
2738 | * show them here either. | |
2739 | */ | |
60f7bb66 | 2740 | if (!kallsyms_show_value(m->file->f_cred)) |
ffb9bd68 MH |
2741 | seq_printf(m, "0x%px-0x%px\t%ps\n", NULL, NULL, |
2742 | (void *)ent->start_addr); | |
2743 | else | |
2744 | seq_printf(m, "0x%px-0x%px\t%ps\n", (void *)ent->start_addr, | |
2745 | (void *)ent->end_addr, (void *)ent->start_addr); | |
63724740 MH |
2746 | return 0; |
2747 | } | |
2748 | ||
4fdd8887 MH |
2749 | static void kprobe_blacklist_seq_stop(struct seq_file *f, void *v) |
2750 | { | |
2751 | mutex_unlock(&kprobe_mutex); | |
2752 | } | |
2753 | ||
eac2cece | 2754 | static const struct seq_operations kprobe_blacklist_sops = { |
63724740 MH |
2755 | .start = kprobe_blacklist_seq_start, |
2756 | .next = kprobe_blacklist_seq_next, | |
4fdd8887 | 2757 | .stop = kprobe_blacklist_seq_stop, |
63724740 MH |
2758 | .show = kprobe_blacklist_seq_show, |
2759 | }; | |
eac2cece | 2760 | DEFINE_SEQ_ATTRIBUTE(kprobe_blacklist); |
63724740 | 2761 | |
12310e34 | 2762 | static int arm_all_kprobes(void) |
bf8f6e5b AM |
2763 | { |
2764 | struct hlist_head *head; | |
bf8f6e5b | 2765 | struct kprobe *p; |
12310e34 JY |
2766 | unsigned int i, total = 0, errors = 0; |
2767 | int err, ret = 0; | |
bf8f6e5b AM |
2768 | |
2769 | mutex_lock(&kprobe_mutex); | |
2770 | ||
e579abeb MH |
2771 | /* If kprobes are armed, just return */ |
2772 | if (!kprobes_all_disarmed) | |
bf8f6e5b AM |
2773 | goto already_enabled; |
2774 | ||
977ad481 WN |
2775 | /* |
2776 | * optimize_kprobe() called by arm_kprobe() checks | |
2777 | * kprobes_all_disarmed, so set kprobes_all_disarmed before | |
2778 | * arm_kprobe. | |
2779 | */ | |
2780 | kprobes_all_disarmed = false; | |
afd66255 | 2781 | /* Arming kprobes doesn't optimize kprobe itself */ |
bf8f6e5b AM |
2782 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
2783 | head = &kprobe_table[i]; | |
12310e34 | 2784 | /* Arm all kprobes on a best-effort basis */ |
7e6a71d8 | 2785 | hlist_for_each_entry(p, head, hlist) { |
12310e34 JY |
2786 | if (!kprobe_disabled(p)) { |
2787 | err = arm_kprobe(p); | |
2788 | if (err) { | |
2789 | errors++; | |
2790 | ret = err; | |
2791 | } | |
2792 | total++; | |
2793 | } | |
2794 | } | |
bf8f6e5b AM |
2795 | } |
2796 | ||
12310e34 JY |
2797 | if (errors) |
2798 | pr_warn("Kprobes globally enabled, but failed to arm %d out of %d probes\n", | |
2799 | errors, total); | |
2800 | else | |
2801 | pr_info("Kprobes globally enabled\n"); | |
bf8f6e5b AM |
2802 | |
2803 | already_enabled: | |
2804 | mutex_unlock(&kprobe_mutex); | |
12310e34 | 2805 | return ret; |
bf8f6e5b AM |
2806 | } |
2807 | ||
297f9233 | 2808 | static int disarm_all_kprobes(void) |
bf8f6e5b AM |
2809 | { |
2810 | struct hlist_head *head; | |
bf8f6e5b | 2811 | struct kprobe *p; |
297f9233 JY |
2812 | unsigned int i, total = 0, errors = 0; |
2813 | int err, ret = 0; | |
bf8f6e5b AM |
2814 | |
2815 | mutex_lock(&kprobe_mutex); | |
2816 | ||
e579abeb | 2817 | /* If kprobes are already disarmed, just return */ |
6274de49 MH |
2818 | if (kprobes_all_disarmed) { |
2819 | mutex_unlock(&kprobe_mutex); | |
297f9233 | 2820 | return 0; |
6274de49 | 2821 | } |
bf8f6e5b | 2822 | |
e579abeb | 2823 | kprobes_all_disarmed = true; |
afd66255 | 2824 | |
bf8f6e5b AM |
2825 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
2826 | head = &kprobe_table[i]; | |
297f9233 | 2827 | /* Disarm all kprobes on a best-effort basis */ |
7e6a71d8 | 2828 | hlist_for_each_entry(p, head, hlist) { |
297f9233 JY |
2829 | if (!arch_trampoline_kprobe(p) && !kprobe_disabled(p)) { |
2830 | err = disarm_kprobe(p, false); | |
2831 | if (err) { | |
2832 | errors++; | |
2833 | ret = err; | |
2834 | } | |
2835 | total++; | |
2836 | } | |
bf8f6e5b AM |
2837 | } |
2838 | } | |
297f9233 JY |
2839 | |
2840 | if (errors) | |
2841 | pr_warn("Kprobes globally disabled, but failed to disarm %d out of %d probes\n", | |
2842 | errors, total); | |
2843 | else | |
2844 | pr_info("Kprobes globally disabled\n"); | |
2845 | ||
bf8f6e5b | 2846 | mutex_unlock(&kprobe_mutex); |
bf8f6e5b | 2847 | |
6274de49 MH |
2848 | /* Wait for disarming all kprobes by optimizer */ |
2849 | wait_for_kprobe_optimizer(); | |
297f9233 JY |
2850 | |
2851 | return ret; | |
bf8f6e5b AM |
2852 | } |
2853 | ||
2854 | /* | |
2855 | * XXX: The debugfs bool file interface doesn't allow for callbacks | |
2856 | * when the bool state is switched. We can reuse that facility when | |
2857 | * available | |
2858 | */ | |
2859 | static ssize_t read_enabled_file_bool(struct file *file, | |
2860 | char __user *user_buf, size_t count, loff_t *ppos) | |
2861 | { | |
2862 | char buf[3]; | |
2863 | ||
e579abeb | 2864 | if (!kprobes_all_disarmed) |
bf8f6e5b AM |
2865 | buf[0] = '1'; |
2866 | else | |
2867 | buf[0] = '0'; | |
2868 | buf[1] = '\n'; | |
2869 | buf[2] = 0x00; | |
2870 | return simple_read_from_buffer(user_buf, count, ppos, buf, 2); | |
2871 | } | |
2872 | ||
2873 | static ssize_t write_enabled_file_bool(struct file *file, | |
2874 | const char __user *user_buf, size_t count, loff_t *ppos) | |
2875 | { | |
2876 | char buf[32]; | |
efeb156e | 2877 | size_t buf_size; |
12310e34 | 2878 | int ret = 0; |
bf8f6e5b AM |
2879 | |
2880 | buf_size = min(count, (sizeof(buf)-1)); | |
2881 | if (copy_from_user(buf, user_buf, buf_size)) | |
2882 | return -EFAULT; | |
2883 | ||
10fb46d5 | 2884 | buf[buf_size] = '\0'; |
bf8f6e5b AM |
2885 | switch (buf[0]) { |
2886 | case 'y': | |
2887 | case 'Y': | |
2888 | case '1': | |
12310e34 | 2889 | ret = arm_all_kprobes(); |
bf8f6e5b AM |
2890 | break; |
2891 | case 'n': | |
2892 | case 'N': | |
2893 | case '0': | |
297f9233 | 2894 | ret = disarm_all_kprobes(); |
bf8f6e5b | 2895 | break; |
10fb46d5 MK |
2896 | default: |
2897 | return -EINVAL; | |
bf8f6e5b AM |
2898 | } |
2899 | ||
12310e34 JY |
2900 | if (ret) |
2901 | return ret; | |
2902 | ||
bf8f6e5b AM |
2903 | return count; |
2904 | } | |
2905 | ||
828c0950 | 2906 | static const struct file_operations fops_kp = { |
bf8f6e5b AM |
2907 | .read = read_enabled_file_bool, |
2908 | .write = write_enabled_file_bool, | |
6038f373 | 2909 | .llseek = default_llseek, |
bf8f6e5b AM |
2910 | }; |
2911 | ||
55479f64 | 2912 | static int __init debugfs_kprobe_init(void) |
346fd59b | 2913 | { |
8c0fd1fa | 2914 | struct dentry *dir; |
bf8f6e5b | 2915 | unsigned int value = 1; |
346fd59b SD |
2916 | |
2917 | dir = debugfs_create_dir("kprobes", NULL); | |
346fd59b | 2918 | |
eac2cece | 2919 | debugfs_create_file("list", 0400, dir, NULL, &kprobes_fops); |
346fd59b | 2920 | |
8c0fd1fa | 2921 | debugfs_create_file("enabled", 0600, dir, &value, &fops_kp); |
63724740 | 2922 | |
8c0fd1fa | 2923 | debugfs_create_file("blacklist", 0400, dir, NULL, |
eac2cece | 2924 | &kprobe_blacklist_fops); |
bf8f6e5b | 2925 | |
346fd59b SD |
2926 | return 0; |
2927 | } | |
2928 | ||
2929 | late_initcall(debugfs_kprobe_init); | |
2930 | #endif /* CONFIG_DEBUG_FS */ |