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Commit | Line | Data |
---|---|---|
413d37d1 | 1 | /* |
77b44d1b | 2 | * Kprobes-based tracing events |
413d37d1 MH |
3 | * |
4 | * Created by Masami Hiramatsu <mhiramat@redhat.com> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
18 | */ | |
72576341 | 19 | #define pr_fmt(fmt) "trace_kprobe: " fmt |
413d37d1 MH |
20 | |
21 | #include <linux/module.h> | |
22 | #include <linux/uaccess.h> | |
b2d09103 | 23 | #include <linux/rculist.h> |
413d37d1 | 24 | |
8ab83f56 | 25 | #include "trace_probe.h" |
1ff511e3 | 26 | |
8ab83f56 | 27 | #define KPROBE_EVENT_SYSTEM "kprobes" |
696ced4f | 28 | #define KRETPROBE_MAXACTIVE_MAX 4096 |
e09c8614 | 29 | |
413d37d1 | 30 | /** |
77b44d1b | 31 | * Kprobe event core functions |
413d37d1 | 32 | */ |
c31ffb3f | 33 | struct trace_kprobe { |
413d37d1 | 34 | struct list_head list; |
4a846b44 | 35 | struct kretprobe rp; /* Use rp.kp for kprobe use */ |
a7636d9e | 36 | unsigned long __percpu *nhit; |
413d37d1 | 37 | const char *symbol; /* symbol name */ |
c31ffb3f | 38 | struct trace_probe tp; |
413d37d1 MH |
39 | }; |
40 | ||
c31ffb3f NK |
41 | #define SIZEOF_TRACE_KPROBE(n) \ |
42 | (offsetof(struct trace_kprobe, tp.args) + \ | |
eca0d916 | 43 | (sizeof(struct probe_arg) * (n))) |
a82378d8 | 44 | |
93ccae7a | 45 | |
3da0f180 | 46 | static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk) |
413d37d1 | 47 | { |
c31ffb3f | 48 | return tk->rp.handler != NULL; |
413d37d1 MH |
49 | } |
50 | ||
3da0f180 | 51 | static nokprobe_inline const char *trace_kprobe_symbol(struct trace_kprobe *tk) |
413d37d1 | 52 | { |
c31ffb3f | 53 | return tk->symbol ? tk->symbol : "unknown"; |
413d37d1 MH |
54 | } |
55 | ||
3da0f180 | 56 | static nokprobe_inline unsigned long trace_kprobe_offset(struct trace_kprobe *tk) |
61424318 | 57 | { |
c31ffb3f | 58 | return tk->rp.kp.offset; |
61424318 MH |
59 | } |
60 | ||
3da0f180 | 61 | static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk) |
61424318 | 62 | { |
c31ffb3f | 63 | return !!(kprobe_gone(&tk->rp.kp)); |
61424318 MH |
64 | } |
65 | ||
3da0f180 | 66 | static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk, |
c31ffb3f | 67 | struct module *mod) |
61424318 MH |
68 | { |
69 | int len = strlen(mod->name); | |
c31ffb3f | 70 | const char *name = trace_kprobe_symbol(tk); |
61424318 MH |
71 | return strncmp(mod->name, name, len) == 0 && name[len] == ':'; |
72 | } | |
73 | ||
7782046e | 74 | static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk) |
61424318 | 75 | { |
7782046e MH |
76 | char *p; |
77 | bool ret; | |
78 | ||
79 | if (!tk->symbol) | |
80 | return false; | |
81 | p = strchr(tk->symbol, ':'); | |
82 | if (!p) | |
83 | return true; | |
84 | *p = '\0'; | |
85 | mutex_lock(&module_mutex); | |
86 | ret = !!find_module(tk->symbol); | |
87 | mutex_unlock(&module_mutex); | |
88 | *p = ':'; | |
89 | ||
90 | return ret; | |
61424318 MH |
91 | } |
92 | ||
f18f97ac MN |
93 | static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk) |
94 | { | |
95 | unsigned long nhit = 0; | |
96 | int cpu; | |
97 | ||
98 | for_each_possible_cpu(cpu) | |
99 | nhit += *per_cpu_ptr(tk->nhit, cpu); | |
100 | ||
101 | return nhit; | |
102 | } | |
103 | ||
c31ffb3f NK |
104 | static int register_kprobe_event(struct trace_kprobe *tk); |
105 | static int unregister_kprobe_event(struct trace_kprobe *tk); | |
413d37d1 MH |
106 | |
107 | static DEFINE_MUTEX(probe_lock); | |
108 | static LIST_HEAD(probe_list); | |
109 | ||
50d78056 MH |
110 | static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); |
111 | static int kretprobe_dispatcher(struct kretprobe_instance *ri, | |
112 | struct pt_regs *regs); | |
113 | ||
1301a44e NK |
114 | /* Memory fetching by symbol */ |
115 | struct symbol_cache { | |
116 | char *symbol; | |
117 | long offset; | |
118 | unsigned long addr; | |
119 | }; | |
120 | ||
121 | unsigned long update_symbol_cache(struct symbol_cache *sc) | |
122 | { | |
123 | sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol); | |
124 | ||
125 | if (sc->addr) | |
126 | sc->addr += sc->offset; | |
127 | ||
128 | return sc->addr; | |
129 | } | |
130 | ||
131 | void free_symbol_cache(struct symbol_cache *sc) | |
132 | { | |
133 | kfree(sc->symbol); | |
134 | kfree(sc); | |
135 | } | |
136 | ||
137 | struct symbol_cache *alloc_symbol_cache(const char *sym, long offset) | |
138 | { | |
139 | struct symbol_cache *sc; | |
140 | ||
141 | if (!sym || strlen(sym) == 0) | |
142 | return NULL; | |
143 | ||
144 | sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL); | |
145 | if (!sc) | |
146 | return NULL; | |
147 | ||
148 | sc->symbol = kstrdup(sym, GFP_KERNEL); | |
149 | if (!sc->symbol) { | |
150 | kfree(sc); | |
151 | return NULL; | |
152 | } | |
153 | sc->offset = offset; | |
154 | update_symbol_cache(sc); | |
155 | ||
156 | return sc; | |
157 | } | |
158 | ||
3fd996a2 NK |
159 | /* |
160 | * Kprobes-specific fetch functions | |
161 | */ | |
162 | #define DEFINE_FETCH_stack(type) \ | |
3da0f180 | 163 | static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs, \ |
3fd996a2 NK |
164 | void *offset, void *dest) \ |
165 | { \ | |
166 | *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \ | |
167 | (unsigned int)((unsigned long)offset)); \ | |
3da0f180 MH |
168 | } \ |
169 | NOKPROBE_SYMBOL(FETCH_FUNC_NAME(stack, type)); | |
170 | ||
3fd996a2 NK |
171 | DEFINE_BASIC_FETCH_FUNCS(stack) |
172 | /* No string on the stack entry */ | |
173 | #define fetch_stack_string NULL | |
174 | #define fetch_stack_string_size NULL | |
175 | ||
5baaa59e | 176 | #define DEFINE_FETCH_memory(type) \ |
3da0f180 | 177 | static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs, \ |
5baaa59e NK |
178 | void *addr, void *dest) \ |
179 | { \ | |
180 | type retval; \ | |
181 | if (probe_kernel_address(addr, retval)) \ | |
182 | *(type *)dest = 0; \ | |
183 | else \ | |
184 | *(type *)dest = retval; \ | |
3da0f180 MH |
185 | } \ |
186 | NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, type)); | |
187 | ||
5baaa59e NK |
188 | DEFINE_BASIC_FETCH_FUNCS(memory) |
189 | /* | |
190 | * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max | |
191 | * length and relative data location. | |
192 | */ | |
3da0f180 MH |
193 | static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, |
194 | void *addr, void *dest) | |
5baaa59e | 195 | { |
5baaa59e NK |
196 | int maxlen = get_rloc_len(*(u32 *)dest); |
197 | u8 *dst = get_rloc_data(dest); | |
1a6877b9 | 198 | long ret; |
5baaa59e NK |
199 | |
200 | if (!maxlen) | |
201 | return; | |
202 | ||
203 | /* | |
204 | * Try to get string again, since the string can be changed while | |
205 | * probing. | |
206 | */ | |
1a6877b9 | 207 | ret = strncpy_from_unsafe(dst, addr, maxlen); |
5baaa59e NK |
208 | |
209 | if (ret < 0) { /* Failed to fetch string */ | |
1a6877b9 | 210 | dst[0] = '\0'; |
5baaa59e NK |
211 | *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest)); |
212 | } else { | |
1a6877b9 | 213 | *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(*(u32 *)dest)); |
5baaa59e NK |
214 | } |
215 | } | |
3da0f180 | 216 | NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string)); |
5baaa59e NK |
217 | |
218 | /* Return the length of string -- including null terminal byte */ | |
3da0f180 MH |
219 | static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, |
220 | void *addr, void *dest) | |
5baaa59e NK |
221 | { |
222 | mm_segment_t old_fs; | |
223 | int ret, len = 0; | |
224 | u8 c; | |
225 | ||
226 | old_fs = get_fs(); | |
227 | set_fs(KERNEL_DS); | |
228 | pagefault_disable(); | |
229 | ||
230 | do { | |
231 | ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1); | |
232 | len++; | |
233 | } while (c && ret == 0 && len < MAX_STRING_SIZE); | |
234 | ||
235 | pagefault_enable(); | |
236 | set_fs(old_fs); | |
237 | ||
238 | if (ret < 0) /* Failed to check the length */ | |
239 | *(u32 *)dest = 0; | |
240 | else | |
241 | *(u32 *)dest = len; | |
242 | } | |
3da0f180 | 243 | NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string_size)); |
5baaa59e | 244 | |
1301a44e | 245 | #define DEFINE_FETCH_symbol(type) \ |
3da0f180 | 246 | void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs, void *data, void *dest)\ |
1301a44e NK |
247 | { \ |
248 | struct symbol_cache *sc = data; \ | |
249 | if (sc->addr) \ | |
250 | fetch_memory_##type(regs, (void *)sc->addr, dest); \ | |
251 | else \ | |
252 | *(type *)dest = 0; \ | |
3da0f180 MH |
253 | } \ |
254 | NOKPROBE_SYMBOL(FETCH_FUNC_NAME(symbol, type)); | |
255 | ||
1301a44e NK |
256 | DEFINE_BASIC_FETCH_FUNCS(symbol) |
257 | DEFINE_FETCH_symbol(string) | |
258 | DEFINE_FETCH_symbol(string_size) | |
259 | ||
b7e0bf34 NK |
260 | /* kprobes don't support file_offset fetch methods */ |
261 | #define fetch_file_offset_u8 NULL | |
262 | #define fetch_file_offset_u16 NULL | |
263 | #define fetch_file_offset_u32 NULL | |
264 | #define fetch_file_offset_u64 NULL | |
265 | #define fetch_file_offset_string NULL | |
266 | #define fetch_file_offset_string_size NULL | |
267 | ||
34fee3a1 | 268 | /* Fetch type information table */ |
d9a16d3a | 269 | static const struct fetch_type kprobes_fetch_type_table[] = { |
34fee3a1 NK |
270 | /* Special types */ |
271 | [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string, | |
272 | sizeof(u32), 1, "__data_loc char[]"), | |
273 | [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32, | |
274 | string_size, sizeof(u32), 0, "u32"), | |
275 | /* Basic types */ | |
276 | ASSIGN_FETCH_TYPE(u8, u8, 0), | |
277 | ASSIGN_FETCH_TYPE(u16, u16, 0), | |
278 | ASSIGN_FETCH_TYPE(u32, u32, 0), | |
279 | ASSIGN_FETCH_TYPE(u64, u64, 0), | |
280 | ASSIGN_FETCH_TYPE(s8, u8, 1), | |
281 | ASSIGN_FETCH_TYPE(s16, u16, 1), | |
282 | ASSIGN_FETCH_TYPE(s32, u32, 1), | |
283 | ASSIGN_FETCH_TYPE(s64, u64, 1), | |
17ce3dc7 MH |
284 | ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0), |
285 | ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0), | |
286 | ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0), | |
287 | ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0), | |
34fee3a1 NK |
288 | |
289 | ASSIGN_FETCH_TYPE_END | |
290 | }; | |
291 | ||
4a846b44 MH |
292 | /* |
293 | * Allocate new trace_probe and initialize it (including kprobes). | |
294 | */ | |
c31ffb3f | 295 | static struct trace_kprobe *alloc_trace_kprobe(const char *group, |
f52487e9 | 296 | const char *event, |
4a846b44 MH |
297 | void *addr, |
298 | const char *symbol, | |
299 | unsigned long offs, | |
696ced4f | 300 | int maxactive, |
3a6b7666 | 301 | int nargs, bool is_return) |
413d37d1 | 302 | { |
c31ffb3f | 303 | struct trace_kprobe *tk; |
6f3cf440 | 304 | int ret = -ENOMEM; |
413d37d1 | 305 | |
c31ffb3f NK |
306 | tk = kzalloc(SIZEOF_TRACE_KPROBE(nargs), GFP_KERNEL); |
307 | if (!tk) | |
6f3cf440 | 308 | return ERR_PTR(ret); |
413d37d1 | 309 | |
a7636d9e MKL |
310 | tk->nhit = alloc_percpu(unsigned long); |
311 | if (!tk->nhit) | |
312 | goto error; | |
313 | ||
413d37d1 | 314 | if (symbol) { |
c31ffb3f NK |
315 | tk->symbol = kstrdup(symbol, GFP_KERNEL); |
316 | if (!tk->symbol) | |
413d37d1 | 317 | goto error; |
c31ffb3f NK |
318 | tk->rp.kp.symbol_name = tk->symbol; |
319 | tk->rp.kp.offset = offs; | |
4a846b44 | 320 | } else |
c31ffb3f | 321 | tk->rp.kp.addr = addr; |
4a846b44 MH |
322 | |
323 | if (is_return) | |
c31ffb3f | 324 | tk->rp.handler = kretprobe_dispatcher; |
4a846b44 | 325 | else |
c31ffb3f | 326 | tk->rp.kp.pre_handler = kprobe_dispatcher; |
4a846b44 | 327 | |
696ced4f AC |
328 | tk->rp.maxactive = maxactive; |
329 | ||
da34634f | 330 | if (!event || !is_good_name(event)) { |
6f3cf440 | 331 | ret = -EINVAL; |
4263565d | 332 | goto error; |
6f3cf440 MH |
333 | } |
334 | ||
c31ffb3f NK |
335 | tk->tp.call.class = &tk->tp.class; |
336 | tk->tp.call.name = kstrdup(event, GFP_KERNEL); | |
337 | if (!tk->tp.call.name) | |
4263565d | 338 | goto error; |
413d37d1 | 339 | |
da34634f | 340 | if (!group || !is_good_name(group)) { |
6f3cf440 | 341 | ret = -EINVAL; |
f52487e9 | 342 | goto error; |
6f3cf440 MH |
343 | } |
344 | ||
c31ffb3f NK |
345 | tk->tp.class.system = kstrdup(group, GFP_KERNEL); |
346 | if (!tk->tp.class.system) | |
f52487e9 MH |
347 | goto error; |
348 | ||
c31ffb3f NK |
349 | INIT_LIST_HEAD(&tk->list); |
350 | INIT_LIST_HEAD(&tk->tp.files); | |
351 | return tk; | |
413d37d1 | 352 | error: |
c31ffb3f NK |
353 | kfree(tk->tp.call.name); |
354 | kfree(tk->symbol); | |
a7636d9e | 355 | free_percpu(tk->nhit); |
c31ffb3f | 356 | kfree(tk); |
6f3cf440 | 357 | return ERR_PTR(ret); |
413d37d1 MH |
358 | } |
359 | ||
c31ffb3f | 360 | static void free_trace_kprobe(struct trace_kprobe *tk) |
413d37d1 MH |
361 | { |
362 | int i; | |
363 | ||
c31ffb3f NK |
364 | for (i = 0; i < tk->tp.nr_args; i++) |
365 | traceprobe_free_probe_arg(&tk->tp.args[i]); | |
413d37d1 | 366 | |
c31ffb3f NK |
367 | kfree(tk->tp.call.class->system); |
368 | kfree(tk->tp.call.name); | |
369 | kfree(tk->symbol); | |
a7636d9e | 370 | free_percpu(tk->nhit); |
c31ffb3f | 371 | kfree(tk); |
413d37d1 MH |
372 | } |
373 | ||
c31ffb3f NK |
374 | static struct trace_kprobe *find_trace_kprobe(const char *event, |
375 | const char *group) | |
413d37d1 | 376 | { |
c31ffb3f | 377 | struct trace_kprobe *tk; |
413d37d1 | 378 | |
c31ffb3f | 379 | list_for_each_entry(tk, &probe_list, list) |
687fcc4a | 380 | if (strcmp(trace_event_name(&tk->tp.call), event) == 0 && |
c31ffb3f NK |
381 | strcmp(tk->tp.call.class->system, group) == 0) |
382 | return tk; | |
413d37d1 MH |
383 | return NULL; |
384 | } | |
385 | ||
41a7dd42 MH |
386 | /* |
387 | * Enable trace_probe | |
388 | * if the file is NULL, enable "perf" handler, or enable "trace" handler. | |
389 | */ | |
390 | static int | |
7f1d2f82 | 391 | enable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) |
1538f888 | 392 | { |
9da1cac2 | 393 | struct event_file_link *link = NULL; |
1538f888 MH |
394 | int ret = 0; |
395 | ||
41a7dd42 | 396 | if (file) { |
b04d52e3 ON |
397 | link = kmalloc(sizeof(*link), GFP_KERNEL); |
398 | if (!link) { | |
41a7dd42 | 399 | ret = -ENOMEM; |
3fe3d619 | 400 | goto out; |
41a7dd42 | 401 | } |
41a7dd42 | 402 | |
b04d52e3 | 403 | link->file = file; |
c31ffb3f | 404 | list_add_tail_rcu(&link->list, &tk->tp.files); |
41a7dd42 | 405 | |
c31ffb3f | 406 | tk->tp.flags |= TP_FLAG_TRACE; |
41a7dd42 | 407 | } else |
c31ffb3f | 408 | tk->tp.flags |= TP_FLAG_PROFILE; |
41a7dd42 | 409 | |
c31ffb3f NK |
410 | if (trace_probe_is_registered(&tk->tp) && !trace_kprobe_has_gone(tk)) { |
411 | if (trace_kprobe_is_return(tk)) | |
412 | ret = enable_kretprobe(&tk->rp); | |
1538f888 | 413 | else |
c31ffb3f | 414 | ret = enable_kprobe(&tk->rp.kp); |
1538f888 | 415 | } |
1f9ea57f AS |
416 | |
417 | if (ret) { | |
418 | if (file) { | |
9da1cac2 SRV |
419 | /* Notice the if is true on not WARN() */ |
420 | if (!WARN_ON_ONCE(!link)) | |
421 | list_del_rcu(&link->list); | |
1f9ea57f AS |
422 | kfree(link); |
423 | tk->tp.flags &= ~TP_FLAG_TRACE; | |
424 | } else { | |
425 | tk->tp.flags &= ~TP_FLAG_PROFILE; | |
426 | } | |
427 | } | |
3fe3d619 | 428 | out: |
1538f888 MH |
429 | return ret; |
430 | } | |
431 | ||
41a7dd42 MH |
432 | /* |
433 | * Disable trace_probe | |
434 | * if the file is NULL, disable "perf" handler, or disable "trace" handler. | |
435 | */ | |
436 | static int | |
7f1d2f82 | 437 | disable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) |
1538f888 | 438 | { |
a232e270 MH |
439 | struct event_file_link *link = NULL; |
440 | int wait = 0; | |
41a7dd42 MH |
441 | int ret = 0; |
442 | ||
41a7dd42 | 443 | if (file) { |
c31ffb3f | 444 | link = find_event_file_link(&tk->tp, file); |
b04d52e3 | 445 | if (!link) { |
41a7dd42 | 446 | ret = -EINVAL; |
3fe3d619 | 447 | goto out; |
41a7dd42 MH |
448 | } |
449 | ||
b04d52e3 | 450 | list_del_rcu(&link->list); |
a232e270 | 451 | wait = 1; |
c31ffb3f | 452 | if (!list_empty(&tk->tp.files)) |
b04d52e3 | 453 | goto out; |
41a7dd42 | 454 | |
c31ffb3f | 455 | tk->tp.flags &= ~TP_FLAG_TRACE; |
41a7dd42 | 456 | } else |
c31ffb3f | 457 | tk->tp.flags &= ~TP_FLAG_PROFILE; |
41a7dd42 | 458 | |
c31ffb3f NK |
459 | if (!trace_probe_is_enabled(&tk->tp) && trace_probe_is_registered(&tk->tp)) { |
460 | if (trace_kprobe_is_return(tk)) | |
461 | disable_kretprobe(&tk->rp); | |
1538f888 | 462 | else |
c31ffb3f | 463 | disable_kprobe(&tk->rp.kp); |
a232e270 | 464 | wait = 1; |
1538f888 | 465 | } |
3fe3d619 | 466 | out: |
a232e270 MH |
467 | if (wait) { |
468 | /* | |
469 | * Synchronize with kprobe_trace_func/kretprobe_trace_func | |
470 | * to ensure disabled (all running handlers are finished). | |
471 | * This is not only for kfree(), but also the caller, | |
472 | * trace_remove_event_call() supposes it for releasing | |
473 | * event_call related objects, which will be accessed in | |
474 | * the kprobe_trace_func/kretprobe_trace_func. | |
475 | */ | |
476 | synchronize_sched(); | |
477 | kfree(link); /* Ignored if link == NULL */ | |
478 | } | |
479 | ||
41a7dd42 | 480 | return ret; |
1538f888 MH |
481 | } |
482 | ||
61424318 | 483 | /* Internal register function - just handle k*probes and flags */ |
c31ffb3f | 484 | static int __register_trace_kprobe(struct trace_kprobe *tk) |
413d37d1 | 485 | { |
7f6878a3 | 486 | int i, ret; |
61424318 | 487 | |
c31ffb3f | 488 | if (trace_probe_is_registered(&tk->tp)) |
61424318 MH |
489 | return -EINVAL; |
490 | ||
c31ffb3f NK |
491 | for (i = 0; i < tk->tp.nr_args; i++) |
492 | traceprobe_update_arg(&tk->tp.args[i]); | |
7f6878a3 | 493 | |
61424318 | 494 | /* Set/clear disabled flag according to tp->flag */ |
c31ffb3f NK |
495 | if (trace_probe_is_enabled(&tk->tp)) |
496 | tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED; | |
61424318 | 497 | else |
c31ffb3f | 498 | tk->rp.kp.flags |= KPROBE_FLAG_DISABLED; |
61424318 | 499 | |
c31ffb3f NK |
500 | if (trace_kprobe_is_return(tk)) |
501 | ret = register_kretprobe(&tk->rp); | |
413d37d1 | 502 | else |
c31ffb3f | 503 | ret = register_kprobe(&tk->rp.kp); |
61424318 | 504 | |
7782046e | 505 | if (ret == 0) { |
c31ffb3f | 506 | tk->tp.flags |= TP_FLAG_REGISTERED; |
7782046e MH |
507 | } else if (ret == -EILSEQ) { |
508 | pr_warn("Probing address(0x%p) is not an instruction boundary.\n", | |
509 | tk->rp.kp.addr); | |
510 | ret = -EINVAL; | |
61424318 | 511 | } |
61424318 MH |
512 | return ret; |
513 | } | |
514 | ||
515 | /* Internal unregister function - just handle k*probes and flags */ | |
c31ffb3f | 516 | static void __unregister_trace_kprobe(struct trace_kprobe *tk) |
61424318 | 517 | { |
c31ffb3f NK |
518 | if (trace_probe_is_registered(&tk->tp)) { |
519 | if (trace_kprobe_is_return(tk)) | |
520 | unregister_kretprobe(&tk->rp); | |
61424318 | 521 | else |
c31ffb3f NK |
522 | unregister_kprobe(&tk->rp.kp); |
523 | tk->tp.flags &= ~TP_FLAG_REGISTERED; | |
61424318 | 524 | /* Cleanup kprobe for reuse */ |
c31ffb3f NK |
525 | if (tk->rp.kp.symbol_name) |
526 | tk->rp.kp.addr = NULL; | |
61424318 MH |
527 | } |
528 | } | |
529 | ||
530 | /* Unregister a trace_probe and probe_event: call with locking probe_lock */ | |
c31ffb3f | 531 | static int unregister_trace_kprobe(struct trace_kprobe *tk) |
61424318 | 532 | { |
02ca1521 | 533 | /* Enabled event can not be unregistered */ |
c31ffb3f | 534 | if (trace_probe_is_enabled(&tk->tp)) |
02ca1521 MH |
535 | return -EBUSY; |
536 | ||
40c32592 | 537 | /* Will fail if probe is being used by ftrace or perf */ |
c31ffb3f | 538 | if (unregister_kprobe_event(tk)) |
40c32592 SRRH |
539 | return -EBUSY; |
540 | ||
c31ffb3f NK |
541 | __unregister_trace_kprobe(tk); |
542 | list_del(&tk->list); | |
02ca1521 MH |
543 | |
544 | return 0; | |
413d37d1 MH |
545 | } |
546 | ||
547 | /* Register a trace_probe and probe_event */ | |
c31ffb3f | 548 | static int register_trace_kprobe(struct trace_kprobe *tk) |
413d37d1 | 549 | { |
c31ffb3f | 550 | struct trace_kprobe *old_tk; |
413d37d1 MH |
551 | int ret; |
552 | ||
553 | mutex_lock(&probe_lock); | |
554 | ||
61424318 | 555 | /* Delete old (same name) event if exist */ |
687fcc4a | 556 | old_tk = find_trace_kprobe(trace_event_name(&tk->tp.call), |
de7b2973 | 557 | tk->tp.call.class->system); |
c31ffb3f NK |
558 | if (old_tk) { |
559 | ret = unregister_trace_kprobe(old_tk); | |
02ca1521 MH |
560 | if (ret < 0) |
561 | goto end; | |
c31ffb3f | 562 | free_trace_kprobe(old_tk); |
2d5e067e | 563 | } |
61424318 MH |
564 | |
565 | /* Register new event */ | |
c31ffb3f | 566 | ret = register_kprobe_event(tk); |
2d5e067e | 567 | if (ret) { |
a395d6a7 | 568 | pr_warn("Failed to register probe event(%d)\n", ret); |
2d5e067e MH |
569 | goto end; |
570 | } | |
571 | ||
61424318 | 572 | /* Register k*probe */ |
c31ffb3f | 573 | ret = __register_trace_kprobe(tk); |
7782046e MH |
574 | if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) { |
575 | pr_warn("This probe might be able to register after target module is loaded. Continue.\n"); | |
576 | ret = 0; | |
577 | } | |
578 | ||
61424318 | 579 | if (ret < 0) |
c31ffb3f | 580 | unregister_kprobe_event(tk); |
61424318 | 581 | else |
c31ffb3f | 582 | list_add_tail(&tk->list, &probe_list); |
61424318 | 583 | |
413d37d1 MH |
584 | end: |
585 | mutex_unlock(&probe_lock); | |
586 | return ret; | |
587 | } | |
588 | ||
61424318 | 589 | /* Module notifier call back, checking event on the module */ |
c31ffb3f | 590 | static int trace_kprobe_module_callback(struct notifier_block *nb, |
61424318 MH |
591 | unsigned long val, void *data) |
592 | { | |
593 | struct module *mod = data; | |
c31ffb3f | 594 | struct trace_kprobe *tk; |
61424318 MH |
595 | int ret; |
596 | ||
597 | if (val != MODULE_STATE_COMING) | |
598 | return NOTIFY_DONE; | |
599 | ||
600 | /* Update probes on coming module */ | |
601 | mutex_lock(&probe_lock); | |
c31ffb3f NK |
602 | list_for_each_entry(tk, &probe_list, list) { |
603 | if (trace_kprobe_within_module(tk, mod)) { | |
02ca1521 | 604 | /* Don't need to check busy - this should have gone. */ |
c31ffb3f NK |
605 | __unregister_trace_kprobe(tk); |
606 | ret = __register_trace_kprobe(tk); | |
61424318 | 607 | if (ret) |
a395d6a7 JP |
608 | pr_warn("Failed to re-register probe %s on %s: %d\n", |
609 | trace_event_name(&tk->tp.call), | |
610 | mod->name, ret); | |
61424318 MH |
611 | } |
612 | } | |
613 | mutex_unlock(&probe_lock); | |
614 | ||
615 | return NOTIFY_DONE; | |
616 | } | |
617 | ||
c31ffb3f NK |
618 | static struct notifier_block trace_kprobe_module_nb = { |
619 | .notifier_call = trace_kprobe_module_callback, | |
61424318 MH |
620 | .priority = 1 /* Invoked after kprobe module callback */ |
621 | }; | |
622 | ||
fca18a47 NR |
623 | /* Convert certain expected symbols into '_' when generating event names */ |
624 | static inline void sanitize_event_name(char *name) | |
625 | { | |
626 | while (*name++ != '\0') | |
627 | if (*name == ':' || *name == '.') | |
628 | *name = '_'; | |
629 | } | |
630 | ||
c31ffb3f | 631 | static int create_trace_kprobe(int argc, char **argv) |
413d37d1 MH |
632 | { |
633 | /* | |
634 | * Argument syntax: | |
696ced4f AC |
635 | * - Add kprobe: |
636 | * p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS] | |
637 | * - Add kretprobe: | |
638 | * r[MAXACTIVE][:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS] | |
413d37d1 | 639 | * Fetch args: |
2e06ff63 MH |
640 | * $retval : fetch return value |
641 | * $stack : fetch stack address | |
642 | * $stackN : fetch Nth of stack (N:0-) | |
35abb67d | 643 | * $comm : fetch current task comm |
413d37d1 MH |
644 | * @ADDR : fetch memory at ADDR (ADDR should be in kernel) |
645 | * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol) | |
646 | * %REG : fetch register REG | |
93ccae7a | 647 | * Dereferencing memory fetch: |
413d37d1 | 648 | * +|-offs(ARG) : fetch memory at ARG +|- offs address. |
eca0d916 MH |
649 | * Alias name of args: |
650 | * NAME=FETCHARG : set NAME as alias of FETCHARG. | |
93ccae7a MH |
651 | * Type of args: |
652 | * FETCHARG:TYPE : use TYPE instead of unsigned long. | |
413d37d1 | 653 | */ |
c31ffb3f | 654 | struct trace_kprobe *tk; |
413d37d1 | 655 | int i, ret = 0; |
3a6b7666 | 656 | bool is_return = false, is_delete = false; |
93ccae7a | 657 | char *symbol = NULL, *event = NULL, *group = NULL; |
696ced4f | 658 | int maxactive = 0; |
da34634f | 659 | char *arg; |
a35ee0b0 | 660 | long offset = 0; |
413d37d1 | 661 | void *addr = NULL; |
4a846b44 | 662 | char buf[MAX_EVENT_NAME_LEN]; |
413d37d1 | 663 | |
a7c312be | 664 | /* argc must be >= 1 */ |
413d37d1 | 665 | if (argv[0][0] == 'p') |
3a6b7666 | 666 | is_return = false; |
413d37d1 | 667 | else if (argv[0][0] == 'r') |
3a6b7666 | 668 | is_return = true; |
a7c312be | 669 | else if (argv[0][0] == '-') |
3a6b7666 | 670 | is_delete = true; |
e63cc239 | 671 | else { |
a7c312be MH |
672 | pr_info("Probe definition must be started with 'p', 'r' or" |
673 | " '-'.\n"); | |
413d37d1 | 674 | return -EINVAL; |
e63cc239 | 675 | } |
413d37d1 | 676 | |
696ced4f AC |
677 | event = strchr(&argv[0][1], ':'); |
678 | if (event) { | |
679 | event[0] = '\0'; | |
680 | event++; | |
681 | } | |
682 | if (is_return && isdigit(argv[0][1])) { | |
683 | ret = kstrtouint(&argv[0][1], 0, &maxactive); | |
684 | if (ret) { | |
685 | pr_info("Failed to parse maxactive.\n"); | |
686 | return ret; | |
687 | } | |
688 | /* kretprobes instances are iterated over via a list. The | |
689 | * maximum should stay reasonable. | |
690 | */ | |
691 | if (maxactive > KRETPROBE_MAXACTIVE_MAX) { | |
692 | pr_info("Maxactive is too big (%d > %d).\n", | |
693 | maxactive, KRETPROBE_MAXACTIVE_MAX); | |
694 | return -E2BIG; | |
695 | } | |
696 | } | |
697 | ||
698 | if (event) { | |
f52487e9 MH |
699 | if (strchr(event, '/')) { |
700 | group = event; | |
701 | event = strchr(group, '/') + 1; | |
702 | event[-1] = '\0'; | |
703 | if (strlen(group) == 0) { | |
a5efd925 | 704 | pr_info("Group name is not specified\n"); |
f52487e9 MH |
705 | return -EINVAL; |
706 | } | |
707 | } | |
413d37d1 | 708 | if (strlen(event) == 0) { |
a5efd925 | 709 | pr_info("Event name is not specified\n"); |
413d37d1 MH |
710 | return -EINVAL; |
711 | } | |
712 | } | |
a7c312be MH |
713 | if (!group) |
714 | group = KPROBE_EVENT_SYSTEM; | |
413d37d1 | 715 | |
a7c312be MH |
716 | if (is_delete) { |
717 | if (!event) { | |
718 | pr_info("Delete command needs an event name.\n"); | |
719 | return -EINVAL; | |
720 | } | |
9da79ab8 | 721 | mutex_lock(&probe_lock); |
c31ffb3f NK |
722 | tk = find_trace_kprobe(event, group); |
723 | if (!tk) { | |
9da79ab8 | 724 | mutex_unlock(&probe_lock); |
a7c312be MH |
725 | pr_info("Event %s/%s doesn't exist.\n", group, event); |
726 | return -ENOENT; | |
727 | } | |
728 | /* delete an event */ | |
c31ffb3f | 729 | ret = unregister_trace_kprobe(tk); |
02ca1521 | 730 | if (ret == 0) |
c31ffb3f | 731 | free_trace_kprobe(tk); |
9da79ab8 | 732 | mutex_unlock(&probe_lock); |
02ca1521 | 733 | return ret; |
a7c312be MH |
734 | } |
735 | ||
736 | if (argc < 2) { | |
737 | pr_info("Probe point is not specified.\n"); | |
738 | return -EINVAL; | |
739 | } | |
9e52b325 SD |
740 | |
741 | /* try to parse an address. if that fails, try to read the | |
742 | * input as a symbol. */ | |
743 | if (kstrtoul(argv[1], 0, (unsigned long *)&addr)) { | |
413d37d1 MH |
744 | /* a symbol specified */ |
745 | symbol = argv[1]; | |
746 | /* TODO: support .init module functions */ | |
8ab83f56 | 747 | ret = traceprobe_split_symbol_offset(symbol, &offset); |
a35ee0b0 | 748 | if (ret || offset < 0 || offset > UINT_MAX) { |
9e52b325 | 749 | pr_info("Failed to parse either an address or a symbol.\n"); |
413d37d1 | 750 | return ret; |
e63cc239 | 751 | } |
d0e02579 | 752 | if (offset && is_return && |
659b957f | 753 | !kprobe_on_func_entry(NULL, symbol, offset)) { |
d0e02579 | 754 | pr_info("Given offset is not valid for return probe.\n"); |
413d37d1 | 755 | return -EINVAL; |
e63cc239 | 756 | } |
413d37d1 | 757 | } |
a82378d8 | 758 | argc -= 2; argv += 2; |
413d37d1 MH |
759 | |
760 | /* setup a probe */ | |
4263565d MH |
761 | if (!event) { |
762 | /* Make a new event name */ | |
4263565d | 763 | if (symbol) |
6f3cf440 | 764 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld", |
4263565d MH |
765 | is_return ? 'r' : 'p', symbol, offset); |
766 | else | |
6f3cf440 | 767 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p", |
4263565d | 768 | is_return ? 'r' : 'p', addr); |
fca18a47 | 769 | sanitize_event_name(buf); |
4a846b44 MH |
770 | event = buf; |
771 | } | |
696ced4f AC |
772 | tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive, |
773 | argc, is_return); | |
c31ffb3f | 774 | if (IS_ERR(tk)) { |
e63cc239 | 775 | pr_info("Failed to allocate trace_probe.(%d)\n", |
c31ffb3f NK |
776 | (int)PTR_ERR(tk)); |
777 | return PTR_ERR(tk); | |
e63cc239 | 778 | } |
413d37d1 | 779 | |
413d37d1 | 780 | /* parse arguments */ |
a82378d8 MH |
781 | ret = 0; |
782 | for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { | |
c31ffb3f NK |
783 | struct probe_arg *parg = &tk->tp.args[i]; |
784 | ||
61a52736 | 785 | /* Increment count for freeing args in error case */ |
c31ffb3f | 786 | tk->tp.nr_args++; |
61a52736 | 787 | |
eca0d916 MH |
788 | /* Parse argument name */ |
789 | arg = strchr(argv[i], '='); | |
aba91595 | 790 | if (arg) { |
eca0d916 | 791 | *arg++ = '\0'; |
c31ffb3f | 792 | parg->name = kstrdup(argv[i], GFP_KERNEL); |
aba91595 | 793 | } else { |
eca0d916 | 794 | arg = argv[i]; |
aba91595 MH |
795 | /* If argument name is omitted, set "argN" */ |
796 | snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1); | |
c31ffb3f | 797 | parg->name = kstrdup(buf, GFP_KERNEL); |
aba91595 | 798 | } |
a703d946 | 799 | |
c31ffb3f | 800 | if (!parg->name) { |
aba91595 | 801 | pr_info("Failed to allocate argument[%d] name.\n", i); |
ba8665d7 | 802 | ret = -ENOMEM; |
413d37d1 MH |
803 | goto error; |
804 | } | |
da34634f | 805 | |
c31ffb3f | 806 | if (!is_good_name(parg->name)) { |
da34634f | 807 | pr_info("Invalid argument[%d] name: %s\n", |
c31ffb3f | 808 | i, parg->name); |
da34634f MH |
809 | ret = -EINVAL; |
810 | goto error; | |
811 | } | |
93ccae7a | 812 | |
c31ffb3f NK |
813 | if (traceprobe_conflict_field_name(parg->name, |
814 | tk->tp.args, i)) { | |
aba91595 | 815 | pr_info("Argument[%d] name '%s' conflicts with " |
93ccae7a MH |
816 | "another field.\n", i, argv[i]); |
817 | ret = -EINVAL; | |
818 | goto error; | |
819 | } | |
ba8665d7 MH |
820 | |
821 | /* Parse fetch argument */ | |
c31ffb3f | 822 | ret = traceprobe_parse_probe_arg(arg, &tk->tp.size, parg, |
d9a16d3a SR |
823 | is_return, true, |
824 | kprobes_fetch_type_table); | |
e63cc239 | 825 | if (ret) { |
aba91595 | 826 | pr_info("Parse error at argument[%d]. (%d)\n", i, ret); |
413d37d1 | 827 | goto error; |
e63cc239 | 828 | } |
413d37d1 | 829 | } |
413d37d1 | 830 | |
c31ffb3f | 831 | ret = register_trace_kprobe(tk); |
413d37d1 MH |
832 | if (ret) |
833 | goto error; | |
834 | return 0; | |
835 | ||
836 | error: | |
c31ffb3f | 837 | free_trace_kprobe(tk); |
413d37d1 MH |
838 | return ret; |
839 | } | |
840 | ||
c31ffb3f | 841 | static int release_all_trace_kprobes(void) |
413d37d1 | 842 | { |
c31ffb3f | 843 | struct trace_kprobe *tk; |
02ca1521 | 844 | int ret = 0; |
413d37d1 MH |
845 | |
846 | mutex_lock(&probe_lock); | |
02ca1521 | 847 | /* Ensure no probe is in use. */ |
c31ffb3f NK |
848 | list_for_each_entry(tk, &probe_list, list) |
849 | if (trace_probe_is_enabled(&tk->tp)) { | |
02ca1521 MH |
850 | ret = -EBUSY; |
851 | goto end; | |
852 | } | |
413d37d1 MH |
853 | /* TODO: Use batch unregistration */ |
854 | while (!list_empty(&probe_list)) { | |
c31ffb3f NK |
855 | tk = list_entry(probe_list.next, struct trace_kprobe, list); |
856 | ret = unregister_trace_kprobe(tk); | |
40c32592 SRRH |
857 | if (ret) |
858 | goto end; | |
c31ffb3f | 859 | free_trace_kprobe(tk); |
413d37d1 | 860 | } |
02ca1521 MH |
861 | |
862 | end: | |
413d37d1 | 863 | mutex_unlock(&probe_lock); |
02ca1521 MH |
864 | |
865 | return ret; | |
413d37d1 MH |
866 | } |
867 | ||
413d37d1 MH |
868 | /* Probes listing interfaces */ |
869 | static void *probes_seq_start(struct seq_file *m, loff_t *pos) | |
870 | { | |
871 | mutex_lock(&probe_lock); | |
872 | return seq_list_start(&probe_list, *pos); | |
873 | } | |
874 | ||
875 | static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos) | |
876 | { | |
877 | return seq_list_next(v, &probe_list, pos); | |
878 | } | |
879 | ||
880 | static void probes_seq_stop(struct seq_file *m, void *v) | |
881 | { | |
882 | mutex_unlock(&probe_lock); | |
883 | } | |
884 | ||
885 | static int probes_seq_show(struct seq_file *m, void *v) | |
886 | { | |
c31ffb3f | 887 | struct trace_kprobe *tk = v; |
93ccae7a | 888 | int i; |
413d37d1 | 889 | |
fa6f0cc7 | 890 | seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p'); |
de7b2973 | 891 | seq_printf(m, ":%s/%s", tk->tp.call.class->system, |
687fcc4a | 892 | trace_event_name(&tk->tp.call)); |
413d37d1 | 893 | |
c31ffb3f NK |
894 | if (!tk->symbol) |
895 | seq_printf(m, " 0x%p", tk->rp.kp.addr); | |
896 | else if (tk->rp.kp.offset) | |
897 | seq_printf(m, " %s+%u", trace_kprobe_symbol(tk), | |
898 | tk->rp.kp.offset); | |
413d37d1 | 899 | else |
c31ffb3f | 900 | seq_printf(m, " %s", trace_kprobe_symbol(tk)); |
413d37d1 | 901 | |
c31ffb3f NK |
902 | for (i = 0; i < tk->tp.nr_args; i++) |
903 | seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm); | |
fa6f0cc7 | 904 | seq_putc(m, '\n'); |
93ccae7a | 905 | |
413d37d1 MH |
906 | return 0; |
907 | } | |
908 | ||
909 | static const struct seq_operations probes_seq_op = { | |
910 | .start = probes_seq_start, | |
911 | .next = probes_seq_next, | |
912 | .stop = probes_seq_stop, | |
913 | .show = probes_seq_show | |
914 | }; | |
915 | ||
916 | static int probes_open(struct inode *inode, struct file *file) | |
917 | { | |
02ca1521 MH |
918 | int ret; |
919 | ||
920 | if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { | |
c31ffb3f | 921 | ret = release_all_trace_kprobes(); |
02ca1521 MH |
922 | if (ret < 0) |
923 | return ret; | |
924 | } | |
413d37d1 MH |
925 | |
926 | return seq_open(file, &probes_seq_op); | |
927 | } | |
928 | ||
413d37d1 MH |
929 | static ssize_t probes_write(struct file *file, const char __user *buffer, |
930 | size_t count, loff_t *ppos) | |
931 | { | |
7e465baa TZ |
932 | return trace_parse_run_command(file, buffer, count, ppos, |
933 | create_trace_kprobe); | |
413d37d1 MH |
934 | } |
935 | ||
936 | static const struct file_operations kprobe_events_ops = { | |
937 | .owner = THIS_MODULE, | |
938 | .open = probes_open, | |
939 | .read = seq_read, | |
940 | .llseek = seq_lseek, | |
941 | .release = seq_release, | |
942 | .write = probes_write, | |
943 | }; | |
944 | ||
cd7e7bd5 MH |
945 | /* Probes profiling interfaces */ |
946 | static int probes_profile_seq_show(struct seq_file *m, void *v) | |
947 | { | |
c31ffb3f | 948 | struct trace_kprobe *tk = v; |
cd7e7bd5 | 949 | |
de7b2973 | 950 | seq_printf(m, " %-44s %15lu %15lu\n", |
f18f97ac MN |
951 | trace_event_name(&tk->tp.call), |
952 | trace_kprobe_nhit(tk), | |
c31ffb3f | 953 | tk->rp.kp.nmissed); |
cd7e7bd5 MH |
954 | |
955 | return 0; | |
956 | } | |
957 | ||
958 | static const struct seq_operations profile_seq_op = { | |
959 | .start = probes_seq_start, | |
960 | .next = probes_seq_next, | |
961 | .stop = probes_seq_stop, | |
962 | .show = probes_profile_seq_show | |
963 | }; | |
964 | ||
965 | static int profile_open(struct inode *inode, struct file *file) | |
966 | { | |
967 | return seq_open(file, &profile_seq_op); | |
968 | } | |
969 | ||
970 | static const struct file_operations kprobe_profile_ops = { | |
971 | .owner = THIS_MODULE, | |
972 | .open = profile_open, | |
973 | .read = seq_read, | |
974 | .llseek = seq_lseek, | |
975 | .release = seq_release, | |
976 | }; | |
977 | ||
413d37d1 | 978 | /* Kprobe handler */ |
3da0f180 | 979 | static nokprobe_inline void |
c31ffb3f | 980 | __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs, |
7f1d2f82 | 981 | struct trace_event_file *trace_file) |
413d37d1 | 982 | { |
93ccae7a | 983 | struct kprobe_trace_entry_head *entry; |
413d37d1 | 984 | struct ring_buffer_event *event; |
8f8ffe24 | 985 | struct ring_buffer *buffer; |
e09c8614 | 986 | int size, dsize, pc; |
413d37d1 | 987 | unsigned long irq_flags; |
2425bcb9 | 988 | struct trace_event_call *call = &tk->tp.call; |
413d37d1 | 989 | |
7f1d2f82 | 990 | WARN_ON(call != trace_file->event_call); |
41a7dd42 | 991 | |
09a5059a | 992 | if (trace_trigger_soft_disabled(trace_file)) |
13a1e4ae | 993 | return; |
b8820084 | 994 | |
413d37d1 MH |
995 | local_save_flags(irq_flags); |
996 | pc = preempt_count(); | |
997 | ||
c31ffb3f NK |
998 | dsize = __get_data_size(&tk->tp, regs); |
999 | size = sizeof(*entry) + tk->tp.size + dsize; | |
413d37d1 | 1000 | |
7f1d2f82 | 1001 | event = trace_event_buffer_lock_reserve(&buffer, trace_file, |
41a7dd42 MH |
1002 | call->event.type, |
1003 | size, irq_flags, pc); | |
413d37d1 | 1004 | if (!event) |
1e12a4a7 | 1005 | return; |
413d37d1 MH |
1006 | |
1007 | entry = ring_buffer_event_data(event); | |
c31ffb3f NK |
1008 | entry->ip = (unsigned long)tk->rp.kp.addr; |
1009 | store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); | |
413d37d1 | 1010 | |
7f1d2f82 | 1011 | event_trigger_unlock_commit_regs(trace_file, buffer, event, |
13a1e4ae | 1012 | entry, irq_flags, pc, regs); |
413d37d1 MH |
1013 | } |
1014 | ||
3da0f180 | 1015 | static void |
c31ffb3f | 1016 | kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs) |
41a7dd42 | 1017 | { |
b04d52e3 | 1018 | struct event_file_link *link; |
41a7dd42 | 1019 | |
c31ffb3f NK |
1020 | list_for_each_entry_rcu(link, &tk->tp.files, list) |
1021 | __kprobe_trace_func(tk, regs, link->file); | |
41a7dd42 | 1022 | } |
3da0f180 | 1023 | NOKPROBE_SYMBOL(kprobe_trace_func); |
41a7dd42 | 1024 | |
413d37d1 | 1025 | /* Kretprobe handler */ |
3da0f180 | 1026 | static nokprobe_inline void |
c31ffb3f | 1027 | __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, |
41a7dd42 | 1028 | struct pt_regs *regs, |
7f1d2f82 | 1029 | struct trace_event_file *trace_file) |
413d37d1 | 1030 | { |
93ccae7a | 1031 | struct kretprobe_trace_entry_head *entry; |
413d37d1 | 1032 | struct ring_buffer_event *event; |
8f8ffe24 | 1033 | struct ring_buffer *buffer; |
e09c8614 | 1034 | int size, pc, dsize; |
413d37d1 | 1035 | unsigned long irq_flags; |
2425bcb9 | 1036 | struct trace_event_call *call = &tk->tp.call; |
413d37d1 | 1037 | |
7f1d2f82 | 1038 | WARN_ON(call != trace_file->event_call); |
41a7dd42 | 1039 | |
09a5059a | 1040 | if (trace_trigger_soft_disabled(trace_file)) |
13a1e4ae | 1041 | return; |
b8820084 | 1042 | |
413d37d1 MH |
1043 | local_save_flags(irq_flags); |
1044 | pc = preempt_count(); | |
1045 | ||
c31ffb3f NK |
1046 | dsize = __get_data_size(&tk->tp, regs); |
1047 | size = sizeof(*entry) + tk->tp.size + dsize; | |
413d37d1 | 1048 | |
7f1d2f82 | 1049 | event = trace_event_buffer_lock_reserve(&buffer, trace_file, |
41a7dd42 MH |
1050 | call->event.type, |
1051 | size, irq_flags, pc); | |
413d37d1 | 1052 | if (!event) |
1e12a4a7 | 1053 | return; |
413d37d1 MH |
1054 | |
1055 | entry = ring_buffer_event_data(event); | |
c31ffb3f | 1056 | entry->func = (unsigned long)tk->rp.kp.addr; |
413d37d1 | 1057 | entry->ret_ip = (unsigned long)ri->ret_addr; |
c31ffb3f | 1058 | store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); |
413d37d1 | 1059 | |
7f1d2f82 | 1060 | event_trigger_unlock_commit_regs(trace_file, buffer, event, |
13a1e4ae | 1061 | entry, irq_flags, pc, regs); |
413d37d1 MH |
1062 | } |
1063 | ||
3da0f180 | 1064 | static void |
c31ffb3f | 1065 | kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, |
41a7dd42 MH |
1066 | struct pt_regs *regs) |
1067 | { | |
b04d52e3 | 1068 | struct event_file_link *link; |
41a7dd42 | 1069 | |
c31ffb3f NK |
1070 | list_for_each_entry_rcu(link, &tk->tp.files, list) |
1071 | __kretprobe_trace_func(tk, ri, regs, link->file); | |
41a7dd42 | 1072 | } |
3da0f180 | 1073 | NOKPROBE_SYMBOL(kretprobe_trace_func); |
41a7dd42 | 1074 | |
413d37d1 | 1075 | /* Event entry printers */ |
b62fdd97 | 1076 | static enum print_line_t |
a9a57763 SR |
1077 | print_kprobe_event(struct trace_iterator *iter, int flags, |
1078 | struct trace_event *event) | |
413d37d1 | 1079 | { |
93ccae7a | 1080 | struct kprobe_trace_entry_head *field; |
413d37d1 | 1081 | struct trace_seq *s = &iter->seq; |
eca0d916 | 1082 | struct trace_probe *tp; |
93ccae7a | 1083 | u8 *data; |
413d37d1 MH |
1084 | int i; |
1085 | ||
93ccae7a | 1086 | field = (struct kprobe_trace_entry_head *)iter->ent; |
80decc70 | 1087 | tp = container_of(event, struct trace_probe, call.event); |
413d37d1 | 1088 | |
687fcc4a | 1089 | trace_seq_printf(s, "%s: (", trace_event_name(&tp->call)); |
6e9f23d1 | 1090 | |
413d37d1 | 1091 | if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) |
85224da0 | 1092 | goto out; |
413d37d1 | 1093 | |
85224da0 | 1094 | trace_seq_putc(s, ')'); |
413d37d1 | 1095 | |
93ccae7a MH |
1096 | data = (u8 *)&field[1]; |
1097 | for (i = 0; i < tp->nr_args; i++) | |
1098 | if (!tp->args[i].type->print(s, tp->args[i].name, | |
e09c8614 | 1099 | data + tp->args[i].offset, field)) |
85224da0 | 1100 | goto out; |
413d37d1 | 1101 | |
85224da0 SRRH |
1102 | trace_seq_putc(s, '\n'); |
1103 | out: | |
1104 | return trace_handle_return(s); | |
413d37d1 MH |
1105 | } |
1106 | ||
b62fdd97 | 1107 | static enum print_line_t |
a9a57763 SR |
1108 | print_kretprobe_event(struct trace_iterator *iter, int flags, |
1109 | struct trace_event *event) | |
413d37d1 | 1110 | { |
93ccae7a | 1111 | struct kretprobe_trace_entry_head *field; |
413d37d1 | 1112 | struct trace_seq *s = &iter->seq; |
eca0d916 | 1113 | struct trace_probe *tp; |
93ccae7a | 1114 | u8 *data; |
413d37d1 MH |
1115 | int i; |
1116 | ||
93ccae7a | 1117 | field = (struct kretprobe_trace_entry_head *)iter->ent; |
80decc70 | 1118 | tp = container_of(event, struct trace_probe, call.event); |
413d37d1 | 1119 | |
687fcc4a | 1120 | trace_seq_printf(s, "%s: (", trace_event_name(&tp->call)); |
6e9f23d1 | 1121 | |
413d37d1 | 1122 | if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET)) |
85224da0 | 1123 | goto out; |
413d37d1 | 1124 | |
85224da0 | 1125 | trace_seq_puts(s, " <- "); |
413d37d1 MH |
1126 | |
1127 | if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET)) | |
85224da0 | 1128 | goto out; |
413d37d1 | 1129 | |
85224da0 | 1130 | trace_seq_putc(s, ')'); |
413d37d1 | 1131 | |
93ccae7a MH |
1132 | data = (u8 *)&field[1]; |
1133 | for (i = 0; i < tp->nr_args; i++) | |
1134 | if (!tp->args[i].type->print(s, tp->args[i].name, | |
e09c8614 | 1135 | data + tp->args[i].offset, field)) |
85224da0 | 1136 | goto out; |
413d37d1 | 1137 | |
85224da0 | 1138 | trace_seq_putc(s, '\n'); |
413d37d1 | 1139 | |
85224da0 SRRH |
1140 | out: |
1141 | return trace_handle_return(s); | |
413d37d1 MH |
1142 | } |
1143 | ||
413d37d1 | 1144 | |
2425bcb9 | 1145 | static int kprobe_event_define_fields(struct trace_event_call *event_call) |
413d37d1 MH |
1146 | { |
1147 | int ret, i; | |
93ccae7a | 1148 | struct kprobe_trace_entry_head field; |
c31ffb3f | 1149 | struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data; |
413d37d1 | 1150 | |
a703d946 | 1151 | DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); |
eca0d916 | 1152 | /* Set argument names as fields */ |
c31ffb3f NK |
1153 | for (i = 0; i < tk->tp.nr_args; i++) { |
1154 | struct probe_arg *parg = &tk->tp.args[i]; | |
1155 | ||
1156 | ret = trace_define_field(event_call, parg->type->fmttype, | |
1157 | parg->name, | |
1158 | sizeof(field) + parg->offset, | |
1159 | parg->type->size, | |
1160 | parg->type->is_signed, | |
93ccae7a MH |
1161 | FILTER_OTHER); |
1162 | if (ret) | |
1163 | return ret; | |
1164 | } | |
413d37d1 MH |
1165 | return 0; |
1166 | } | |
1167 | ||
2425bcb9 | 1168 | static int kretprobe_event_define_fields(struct trace_event_call *event_call) |
413d37d1 MH |
1169 | { |
1170 | int ret, i; | |
93ccae7a | 1171 | struct kretprobe_trace_entry_head field; |
c31ffb3f | 1172 | struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data; |
413d37d1 | 1173 | |
a703d946 MH |
1174 | DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0); |
1175 | DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0); | |
eca0d916 | 1176 | /* Set argument names as fields */ |
c31ffb3f NK |
1177 | for (i = 0; i < tk->tp.nr_args; i++) { |
1178 | struct probe_arg *parg = &tk->tp.args[i]; | |
1179 | ||
1180 | ret = trace_define_field(event_call, parg->type->fmttype, | |
1181 | parg->name, | |
1182 | sizeof(field) + parg->offset, | |
1183 | parg->type->size, | |
1184 | parg->type->is_signed, | |
93ccae7a MH |
1185 | FILTER_OTHER); |
1186 | if (ret) | |
1187 | return ret; | |
1188 | } | |
413d37d1 MH |
1189 | return 0; |
1190 | } | |
1191 | ||
07b139c8 | 1192 | #ifdef CONFIG_PERF_EVENTS |
e08d1c65 MH |
1193 | |
1194 | /* Kprobe profile handler */ | |
f3edacbd | 1195 | static void |
c31ffb3f | 1196 | kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs) |
e08d1c65 | 1197 | { |
2425bcb9 | 1198 | struct trace_event_call *call = &tk->tp.call; |
93ccae7a | 1199 | struct kprobe_trace_entry_head *entry; |
1c024eca | 1200 | struct hlist_head *head; |
e09c8614 | 1201 | int size, __size, dsize; |
4ed7c92d | 1202 | int rctx; |
e08d1c65 | 1203 | |
f3edacbd DM |
1204 | if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs)) |
1205 | return; | |
2541517c | 1206 | |
288e984e ON |
1207 | head = this_cpu_ptr(call->perf_events); |
1208 | if (hlist_empty(head)) | |
f3edacbd | 1209 | return; |
288e984e | 1210 | |
c31ffb3f NK |
1211 | dsize = __get_data_size(&tk->tp, regs); |
1212 | __size = sizeof(*entry) + tk->tp.size + dsize; | |
74ebb63e MH |
1213 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); |
1214 | size -= sizeof(u32); | |
ce71b9df | 1215 | |
1e1dcd93 | 1216 | entry = perf_trace_buf_alloc(size, NULL, &rctx); |
430ad5a6 | 1217 | if (!entry) |
f3edacbd | 1218 | return; |
a1a138d0 | 1219 | |
c31ffb3f | 1220 | entry->ip = (unsigned long)tk->rp.kp.addr; |
e09c8614 | 1221 | memset(&entry[1], 0, dsize); |
c31ffb3f | 1222 | store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); |
1e1dcd93 | 1223 | perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, |
8fd0fbbe | 1224 | head, NULL); |
e08d1c65 | 1225 | } |
3da0f180 | 1226 | NOKPROBE_SYMBOL(kprobe_perf_func); |
e08d1c65 MH |
1227 | |
1228 | /* Kretprobe profile handler */ | |
3da0f180 | 1229 | static void |
c31ffb3f | 1230 | kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, |
2b106aab | 1231 | struct pt_regs *regs) |
e08d1c65 | 1232 | { |
2425bcb9 | 1233 | struct trace_event_call *call = &tk->tp.call; |
93ccae7a | 1234 | struct kretprobe_trace_entry_head *entry; |
1c024eca | 1235 | struct hlist_head *head; |
e09c8614 | 1236 | int size, __size, dsize; |
4ed7c92d | 1237 | int rctx; |
e08d1c65 | 1238 | |
e87c6bc3 | 1239 | if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs)) |
2541517c AS |
1240 | return; |
1241 | ||
288e984e ON |
1242 | head = this_cpu_ptr(call->perf_events); |
1243 | if (hlist_empty(head)) | |
1244 | return; | |
1245 | ||
c31ffb3f NK |
1246 | dsize = __get_data_size(&tk->tp, regs); |
1247 | __size = sizeof(*entry) + tk->tp.size + dsize; | |
74ebb63e MH |
1248 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); |
1249 | size -= sizeof(u32); | |
444a2a3b | 1250 | |
1e1dcd93 | 1251 | entry = perf_trace_buf_alloc(size, NULL, &rctx); |
430ad5a6 | 1252 | if (!entry) |
1e12a4a7 | 1253 | return; |
e08d1c65 | 1254 | |
c31ffb3f | 1255 | entry->func = (unsigned long)tk->rp.kp.addr; |
a1a138d0 | 1256 | entry->ret_ip = (unsigned long)ri->ret_addr; |
c31ffb3f | 1257 | store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); |
1e1dcd93 | 1258 | perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, |
8fd0fbbe | 1259 | head, NULL); |
e08d1c65 | 1260 | } |
3da0f180 | 1261 | NOKPROBE_SYMBOL(kretprobe_perf_func); |
07b139c8 | 1262 | #endif /* CONFIG_PERF_EVENTS */ |
50d78056 | 1263 | |
3fe3d619 ON |
1264 | /* |
1265 | * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex. | |
1266 | * | |
1267 | * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe | |
1268 | * lockless, but we can't race with this __init function. | |
1269 | */ | |
2425bcb9 | 1270 | static int kprobe_register(struct trace_event_call *event, |
fbc1963d | 1271 | enum trace_reg type, void *data) |
2239291a | 1272 | { |
c31ffb3f | 1273 | struct trace_kprobe *tk = (struct trace_kprobe *)event->data; |
7f1d2f82 | 1274 | struct trace_event_file *file = data; |
1538f888 | 1275 | |
2239291a SR |
1276 | switch (type) { |
1277 | case TRACE_REG_REGISTER: | |
c31ffb3f | 1278 | return enable_trace_kprobe(tk, file); |
2239291a | 1279 | case TRACE_REG_UNREGISTER: |
c31ffb3f | 1280 | return disable_trace_kprobe(tk, file); |
2239291a SR |
1281 | |
1282 | #ifdef CONFIG_PERF_EVENTS | |
1283 | case TRACE_REG_PERF_REGISTER: | |
c31ffb3f | 1284 | return enable_trace_kprobe(tk, NULL); |
2239291a | 1285 | case TRACE_REG_PERF_UNREGISTER: |
c31ffb3f | 1286 | return disable_trace_kprobe(tk, NULL); |
ceec0b6f JO |
1287 | case TRACE_REG_PERF_OPEN: |
1288 | case TRACE_REG_PERF_CLOSE: | |
489c75c3 JO |
1289 | case TRACE_REG_PERF_ADD: |
1290 | case TRACE_REG_PERF_DEL: | |
ceec0b6f | 1291 | return 0; |
2239291a SR |
1292 | #endif |
1293 | } | |
1294 | return 0; | |
1295 | } | |
50d78056 | 1296 | |
3da0f180 | 1297 | static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) |
50d78056 | 1298 | { |
c31ffb3f | 1299 | struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp); |
e08d1c65 | 1300 | |
a7636d9e | 1301 | raw_cpu_inc(*tk->nhit); |
48182bd2 | 1302 | |
c31ffb3f NK |
1303 | if (tk->tp.flags & TP_FLAG_TRACE) |
1304 | kprobe_trace_func(tk, regs); | |
07b139c8 | 1305 | #ifdef CONFIG_PERF_EVENTS |
c31ffb3f | 1306 | if (tk->tp.flags & TP_FLAG_PROFILE) |
f3edacbd | 1307 | kprobe_perf_func(tk, regs); |
07b139c8 | 1308 | #endif |
f3edacbd | 1309 | return 0; /* We don't tweek kernel, so just return 0 */ |
50d78056 | 1310 | } |
3da0f180 | 1311 | NOKPROBE_SYMBOL(kprobe_dispatcher); |
50d78056 | 1312 | |
3da0f180 MH |
1313 | static int |
1314 | kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) | |
50d78056 | 1315 | { |
c31ffb3f | 1316 | struct trace_kprobe *tk = container_of(ri->rp, struct trace_kprobe, rp); |
50d78056 | 1317 | |
a7636d9e | 1318 | raw_cpu_inc(*tk->nhit); |
48182bd2 | 1319 | |
c31ffb3f NK |
1320 | if (tk->tp.flags & TP_FLAG_TRACE) |
1321 | kretprobe_trace_func(tk, ri, regs); | |
07b139c8 | 1322 | #ifdef CONFIG_PERF_EVENTS |
c31ffb3f NK |
1323 | if (tk->tp.flags & TP_FLAG_PROFILE) |
1324 | kretprobe_perf_func(tk, ri, regs); | |
07b139c8 | 1325 | #endif |
50d78056 MH |
1326 | return 0; /* We don't tweek kernel, so just return 0 */ |
1327 | } | |
3da0f180 | 1328 | NOKPROBE_SYMBOL(kretprobe_dispatcher); |
e08d1c65 | 1329 | |
a9a57763 SR |
1330 | static struct trace_event_functions kretprobe_funcs = { |
1331 | .trace = print_kretprobe_event | |
1332 | }; | |
1333 | ||
1334 | static struct trace_event_functions kprobe_funcs = { | |
1335 | .trace = print_kprobe_event | |
1336 | }; | |
1337 | ||
c31ffb3f | 1338 | static int register_kprobe_event(struct trace_kprobe *tk) |
413d37d1 | 1339 | { |
2425bcb9 | 1340 | struct trace_event_call *call = &tk->tp.call; |
413d37d1 MH |
1341 | int ret; |
1342 | ||
2425bcb9 | 1343 | /* Initialize trace_event_call */ |
ffb9f995 | 1344 | INIT_LIST_HEAD(&call->class->fields); |
c31ffb3f | 1345 | if (trace_kprobe_is_return(tk)) { |
80decc70 | 1346 | call->event.funcs = &kretprobe_funcs; |
2e33af02 | 1347 | call->class->define_fields = kretprobe_event_define_fields; |
413d37d1 | 1348 | } else { |
80decc70 | 1349 | call->event.funcs = &kprobe_funcs; |
2e33af02 | 1350 | call->class->define_fields = kprobe_event_define_fields; |
413d37d1 | 1351 | } |
5bf652aa | 1352 | if (set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) |
a342a028 | 1353 | return -ENOMEM; |
9023c930 | 1354 | ret = register_trace_event(&call->event); |
32c0edae | 1355 | if (!ret) { |
a342a028 | 1356 | kfree(call->print_fmt); |
ff50d991 | 1357 | return -ENODEV; |
a342a028 | 1358 | } |
72cbbc89 | 1359 | call->flags = TRACE_EVENT_FL_KPROBE; |
2239291a | 1360 | call->class->reg = kprobe_register; |
c31ffb3f | 1361 | call->data = tk; |
413d37d1 | 1362 | ret = trace_add_event_call(call); |
ff50d991 | 1363 | if (ret) { |
de7b2973 | 1364 | pr_info("Failed to register kprobe event: %s\n", |
687fcc4a | 1365 | trace_event_name(call)); |
a342a028 | 1366 | kfree(call->print_fmt); |
9023c930 | 1367 | unregister_trace_event(&call->event); |
ff50d991 | 1368 | } |
413d37d1 MH |
1369 | return ret; |
1370 | } | |
1371 | ||
c31ffb3f | 1372 | static int unregister_kprobe_event(struct trace_kprobe *tk) |
413d37d1 | 1373 | { |
40c32592 SRRH |
1374 | int ret; |
1375 | ||
ff50d991 | 1376 | /* tp->event is unregistered in trace_remove_event_call() */ |
c31ffb3f | 1377 | ret = trace_remove_event_call(&tk->tp.call); |
40c32592 | 1378 | if (!ret) |
c31ffb3f | 1379 | kfree(tk->tp.call.print_fmt); |
40c32592 | 1380 | return ret; |
413d37d1 MH |
1381 | } |
1382 | ||
8434dc93 | 1383 | /* Make a tracefs interface for controlling probe points */ |
413d37d1 MH |
1384 | static __init int init_kprobe_trace(void) |
1385 | { | |
1386 | struct dentry *d_tracer; | |
1387 | struct dentry *entry; | |
413d37d1 | 1388 | |
c31ffb3f | 1389 | if (register_module_notifier(&trace_kprobe_module_nb)) |
61424318 MH |
1390 | return -EINVAL; |
1391 | ||
413d37d1 | 1392 | d_tracer = tracing_init_dentry(); |
14a5ae40 | 1393 | if (IS_ERR(d_tracer)) |
413d37d1 MH |
1394 | return 0; |
1395 | ||
8434dc93 | 1396 | entry = tracefs_create_file("kprobe_events", 0644, d_tracer, |
413d37d1 MH |
1397 | NULL, &kprobe_events_ops); |
1398 | ||
cd7e7bd5 | 1399 | /* Event list interface */ |
413d37d1 | 1400 | if (!entry) |
a395d6a7 | 1401 | pr_warn("Could not create tracefs 'kprobe_events' entry\n"); |
cd7e7bd5 MH |
1402 | |
1403 | /* Profile interface */ | |
8434dc93 | 1404 | entry = tracefs_create_file("kprobe_profile", 0444, d_tracer, |
cd7e7bd5 MH |
1405 | NULL, &kprobe_profile_ops); |
1406 | ||
1407 | if (!entry) | |
a395d6a7 | 1408 | pr_warn("Could not create tracefs 'kprobe_profile' entry\n"); |
413d37d1 MH |
1409 | return 0; |
1410 | } | |
1411 | fs_initcall(init_kprobe_trace); | |
1412 | ||
1413 | ||
1414 | #ifdef CONFIG_FTRACE_STARTUP_TEST | |
265a5b7e SR |
1415 | /* |
1416 | * The "__used" keeps gcc from removing the function symbol | |
d4d7ccc8 MN |
1417 | * from the kallsyms table. 'noinline' makes sure that there |
1418 | * isn't an inlined version used by the test method below | |
265a5b7e | 1419 | */ |
d4d7ccc8 MN |
1420 | static __used __init noinline int |
1421 | kprobe_trace_selftest_target(int a1, int a2, int a3, int a4, int a5, int a6) | |
413d37d1 MH |
1422 | { |
1423 | return a1 + a2 + a3 + a4 + a5 + a6; | |
1424 | } | |
1425 | ||
26a346f2 | 1426 | static __init struct trace_event_file * |
c31ffb3f | 1427 | find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr) |
41a7dd42 | 1428 | { |
7f1d2f82 | 1429 | struct trace_event_file *file; |
41a7dd42 MH |
1430 | |
1431 | list_for_each_entry(file, &tr->events, list) | |
c31ffb3f | 1432 | if (file->event_call == &tk->tp.call) |
41a7dd42 MH |
1433 | return file; |
1434 | ||
1435 | return NULL; | |
1436 | } | |
1437 | ||
3fe3d619 | 1438 | /* |
c31ffb3f | 1439 | * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this |
3fe3d619 ON |
1440 | * stage, we can do this lockless. |
1441 | */ | |
413d37d1 MH |
1442 | static __init int kprobe_trace_self_tests_init(void) |
1443 | { | |
231e36f4 | 1444 | int ret, warn = 0; |
413d37d1 | 1445 | int (*target)(int, int, int, int, int, int); |
c31ffb3f | 1446 | struct trace_kprobe *tk; |
7f1d2f82 | 1447 | struct trace_event_file *file; |
413d37d1 | 1448 | |
748ec3a2 YY |
1449 | if (tracing_is_disabled()) |
1450 | return -ENODEV; | |
1451 | ||
413d37d1 MH |
1452 | target = kprobe_trace_selftest_target; |
1453 | ||
1454 | pr_info("Testing kprobe tracing: "); | |
1455 | ||
7e465baa TZ |
1456 | ret = trace_run_command("p:testprobe kprobe_trace_selftest_target " |
1457 | "$stack $stack0 +0($stack)", | |
1458 | create_trace_kprobe); | |
231e36f4 | 1459 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1460 | pr_warn("error on probing function entry.\n"); |
231e36f4 MH |
1461 | warn++; |
1462 | } else { | |
1463 | /* Enable trace point */ | |
c31ffb3f NK |
1464 | tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); |
1465 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1466 | pr_warn("error on getting new probe.\n"); |
231e36f4 | 1467 | warn++; |
41a7dd42 | 1468 | } else { |
c31ffb3f | 1469 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1470 | if (WARN_ON_ONCE(file == NULL)) { |
1471 | pr_warn("error on getting probe file.\n"); | |
1472 | warn++; | |
1473 | } else | |
c31ffb3f | 1474 | enable_trace_kprobe(tk, file); |
41a7dd42 | 1475 | } |
231e36f4 | 1476 | } |
413d37d1 | 1477 | |
7e465baa TZ |
1478 | ret = trace_run_command("r:testprobe2 kprobe_trace_selftest_target " |
1479 | "$retval", create_trace_kprobe); | |
231e36f4 | 1480 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1481 | pr_warn("error on probing function return.\n"); |
231e36f4 MH |
1482 | warn++; |
1483 | } else { | |
1484 | /* Enable trace point */ | |
c31ffb3f NK |
1485 | tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); |
1486 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1487 | pr_warn("error on getting 2nd new probe.\n"); |
231e36f4 | 1488 | warn++; |
41a7dd42 | 1489 | } else { |
c31ffb3f | 1490 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1491 | if (WARN_ON_ONCE(file == NULL)) { |
1492 | pr_warn("error on getting probe file.\n"); | |
1493 | warn++; | |
1494 | } else | |
c31ffb3f | 1495 | enable_trace_kprobe(tk, file); |
41a7dd42 | 1496 | } |
231e36f4 MH |
1497 | } |
1498 | ||
1499 | if (warn) | |
1500 | goto end; | |
413d37d1 MH |
1501 | |
1502 | ret = target(1, 2, 3, 4, 5, 6); | |
1503 | ||
d4d7ccc8 MN |
1504 | /* |
1505 | * Not expecting an error here, the check is only to prevent the | |
1506 | * optimizer from removing the call to target() as otherwise there | |
1507 | * are no side-effects and the call is never performed. | |
1508 | */ | |
1509 | if (ret != 21) | |
1510 | warn++; | |
1511 | ||
02ca1521 | 1512 | /* Disable trace points before removing it */ |
c31ffb3f NK |
1513 | tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); |
1514 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1515 | pr_warn("error on getting test probe.\n"); |
02ca1521 | 1516 | warn++; |
41a7dd42 | 1517 | } else { |
d4d7ccc8 MN |
1518 | if (trace_kprobe_nhit(tk) != 1) { |
1519 | pr_warn("incorrect number of testprobe hits\n"); | |
1520 | warn++; | |
1521 | } | |
1522 | ||
c31ffb3f | 1523 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1524 | if (WARN_ON_ONCE(file == NULL)) { |
1525 | pr_warn("error on getting probe file.\n"); | |
1526 | warn++; | |
1527 | } else | |
c31ffb3f | 1528 | disable_trace_kprobe(tk, file); |
41a7dd42 | 1529 | } |
02ca1521 | 1530 | |
c31ffb3f NK |
1531 | tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); |
1532 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1533 | pr_warn("error on getting 2nd test probe.\n"); |
02ca1521 | 1534 | warn++; |
41a7dd42 | 1535 | } else { |
d4d7ccc8 MN |
1536 | if (trace_kprobe_nhit(tk) != 1) { |
1537 | pr_warn("incorrect number of testprobe2 hits\n"); | |
1538 | warn++; | |
1539 | } | |
1540 | ||
c31ffb3f | 1541 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1542 | if (WARN_ON_ONCE(file == NULL)) { |
1543 | pr_warn("error on getting probe file.\n"); | |
1544 | warn++; | |
1545 | } else | |
c31ffb3f | 1546 | disable_trace_kprobe(tk, file); |
41a7dd42 | 1547 | } |
02ca1521 | 1548 | |
7e465baa | 1549 | ret = trace_run_command("-:testprobe", create_trace_kprobe); |
231e36f4 | 1550 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1551 | pr_warn("error on deleting a probe.\n"); |
231e36f4 MH |
1552 | warn++; |
1553 | } | |
1554 | ||
7e465baa | 1555 | ret = trace_run_command("-:testprobe2", create_trace_kprobe); |
231e36f4 | 1556 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1557 | pr_warn("error on deleting a probe.\n"); |
231e36f4 MH |
1558 | warn++; |
1559 | } | |
413d37d1 | 1560 | |
231e36f4 | 1561 | end: |
c31ffb3f | 1562 | release_all_trace_kprobes(); |
30e7d894 TG |
1563 | /* |
1564 | * Wait for the optimizer work to finish. Otherwise it might fiddle | |
1565 | * with probes in already freed __init text. | |
1566 | */ | |
1567 | wait_for_kprobe_optimizer(); | |
231e36f4 MH |
1568 | if (warn) |
1569 | pr_cont("NG: Some tests are failed. Please check them.\n"); | |
1570 | else | |
1571 | pr_cont("OK\n"); | |
413d37d1 MH |
1572 | return 0; |
1573 | } | |
1574 | ||
1575 | late_initcall(kprobe_trace_self_tests_init); | |
1576 | ||
1577 | #endif |