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1 | /* | |
2 | * Kprobes-based tracing events | |
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 | */ | |
19 | ||
20 | #include <linux/module.h> | |
21 | #include <linux/uaccess.h> | |
22 | ||
23 | #include "trace_probe.h" | |
24 | ||
25 | #define KPROBE_EVENT_SYSTEM "kprobes" | |
26 | ||
27 | /** | |
28 | * Kprobe event core functions | |
29 | */ | |
30 | ||
31 | struct trace_probe { | |
32 | struct list_head list; | |
33 | struct kretprobe rp; /* Use rp.kp for kprobe use */ | |
34 | unsigned long nhit; | |
35 | unsigned int flags; /* For TP_FLAG_* */ | |
36 | const char *symbol; /* symbol name */ | |
37 | struct ftrace_event_class class; | |
38 | struct ftrace_event_call call; | |
39 | ssize_t size; /* trace entry size */ | |
40 | unsigned int nr_args; | |
41 | struct probe_arg args[]; | |
42 | }; | |
43 | ||
44 | #define SIZEOF_TRACE_PROBE(n) \ | |
45 | (offsetof(struct trace_probe, args) + \ | |
46 | (sizeof(struct probe_arg) * (n))) | |
47 | ||
48 | ||
49 | static __kprobes int trace_probe_is_return(struct trace_probe *tp) | |
50 | { | |
51 | return tp->rp.handler != NULL; | |
52 | } | |
53 | ||
54 | static __kprobes const char *trace_probe_symbol(struct trace_probe *tp) | |
55 | { | |
56 | return tp->symbol ? tp->symbol : "unknown"; | |
57 | } | |
58 | ||
59 | static __kprobes unsigned long trace_probe_offset(struct trace_probe *tp) | |
60 | { | |
61 | return tp->rp.kp.offset; | |
62 | } | |
63 | ||
64 | static __kprobes bool trace_probe_is_enabled(struct trace_probe *tp) | |
65 | { | |
66 | return !!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE)); | |
67 | } | |
68 | ||
69 | static __kprobes bool trace_probe_is_registered(struct trace_probe *tp) | |
70 | { | |
71 | return !!(tp->flags & TP_FLAG_REGISTERED); | |
72 | } | |
73 | ||
74 | static __kprobes bool trace_probe_has_gone(struct trace_probe *tp) | |
75 | { | |
76 | return !!(kprobe_gone(&tp->rp.kp)); | |
77 | } | |
78 | ||
79 | static __kprobes bool trace_probe_within_module(struct trace_probe *tp, | |
80 | struct module *mod) | |
81 | { | |
82 | int len = strlen(mod->name); | |
83 | const char *name = trace_probe_symbol(tp); | |
84 | return strncmp(mod->name, name, len) == 0 && name[len] == ':'; | |
85 | } | |
86 | ||
87 | static __kprobes bool trace_probe_is_on_module(struct trace_probe *tp) | |
88 | { | |
89 | return !!strchr(trace_probe_symbol(tp), ':'); | |
90 | } | |
91 | ||
92 | static int register_probe_event(struct trace_probe *tp); | |
93 | static void unregister_probe_event(struct trace_probe *tp); | |
94 | ||
95 | static DEFINE_MUTEX(probe_lock); | |
96 | static LIST_HEAD(probe_list); | |
97 | ||
98 | static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); | |
99 | static int kretprobe_dispatcher(struct kretprobe_instance *ri, | |
100 | struct pt_regs *regs); | |
101 | ||
102 | /* | |
103 | * Allocate new trace_probe and initialize it (including kprobes). | |
104 | */ | |
105 | static struct trace_probe *alloc_trace_probe(const char *group, | |
106 | const char *event, | |
107 | void *addr, | |
108 | const char *symbol, | |
109 | unsigned long offs, | |
110 | int nargs, bool is_return) | |
111 | { | |
112 | struct trace_probe *tp; | |
113 | int ret = -ENOMEM; | |
114 | ||
115 | tp = kzalloc(SIZEOF_TRACE_PROBE(nargs), GFP_KERNEL); | |
116 | if (!tp) | |
117 | return ERR_PTR(ret); | |
118 | ||
119 | if (symbol) { | |
120 | tp->symbol = kstrdup(symbol, GFP_KERNEL); | |
121 | if (!tp->symbol) | |
122 | goto error; | |
123 | tp->rp.kp.symbol_name = tp->symbol; | |
124 | tp->rp.kp.offset = offs; | |
125 | } else | |
126 | tp->rp.kp.addr = addr; | |
127 | ||
128 | if (is_return) | |
129 | tp->rp.handler = kretprobe_dispatcher; | |
130 | else | |
131 | tp->rp.kp.pre_handler = kprobe_dispatcher; | |
132 | ||
133 | if (!event || !is_good_name(event)) { | |
134 | ret = -EINVAL; | |
135 | goto error; | |
136 | } | |
137 | ||
138 | tp->call.class = &tp->class; | |
139 | tp->call.name = kstrdup(event, GFP_KERNEL); | |
140 | if (!tp->call.name) | |
141 | goto error; | |
142 | ||
143 | if (!group || !is_good_name(group)) { | |
144 | ret = -EINVAL; | |
145 | goto error; | |
146 | } | |
147 | ||
148 | tp->class.system = kstrdup(group, GFP_KERNEL); | |
149 | if (!tp->class.system) | |
150 | goto error; | |
151 | ||
152 | INIT_LIST_HEAD(&tp->list); | |
153 | return tp; | |
154 | error: | |
155 | kfree(tp->call.name); | |
156 | kfree(tp->symbol); | |
157 | kfree(tp); | |
158 | return ERR_PTR(ret); | |
159 | } | |
160 | ||
161 | static void free_trace_probe(struct trace_probe *tp) | |
162 | { | |
163 | int i; | |
164 | ||
165 | for (i = 0; i < tp->nr_args; i++) | |
166 | traceprobe_free_probe_arg(&tp->args[i]); | |
167 | ||
168 | kfree(tp->call.class->system); | |
169 | kfree(tp->call.name); | |
170 | kfree(tp->symbol); | |
171 | kfree(tp); | |
172 | } | |
173 | ||
174 | static struct trace_probe *find_trace_probe(const char *event, | |
175 | const char *group) | |
176 | { | |
177 | struct trace_probe *tp; | |
178 | ||
179 | list_for_each_entry(tp, &probe_list, list) | |
180 | if (strcmp(tp->call.name, event) == 0 && | |
181 | strcmp(tp->call.class->system, group) == 0) | |
182 | return tp; | |
183 | return NULL; | |
184 | } | |
185 | ||
186 | /* Enable trace_probe - @flag must be TP_FLAG_TRACE or TP_FLAG_PROFILE */ | |
187 | static int enable_trace_probe(struct trace_probe *tp, int flag) | |
188 | { | |
189 | int ret = 0; | |
190 | ||
191 | tp->flags |= flag; | |
192 | if (trace_probe_is_enabled(tp) && trace_probe_is_registered(tp) && | |
193 | !trace_probe_has_gone(tp)) { | |
194 | if (trace_probe_is_return(tp)) | |
195 | ret = enable_kretprobe(&tp->rp); | |
196 | else | |
197 | ret = enable_kprobe(&tp->rp.kp); | |
198 | } | |
199 | ||
200 | return ret; | |
201 | } | |
202 | ||
203 | /* Disable trace_probe - @flag must be TP_FLAG_TRACE or TP_FLAG_PROFILE */ | |
204 | static void disable_trace_probe(struct trace_probe *tp, int flag) | |
205 | { | |
206 | tp->flags &= ~flag; | |
207 | if (!trace_probe_is_enabled(tp) && trace_probe_is_registered(tp)) { | |
208 | if (trace_probe_is_return(tp)) | |
209 | disable_kretprobe(&tp->rp); | |
210 | else | |
211 | disable_kprobe(&tp->rp.kp); | |
212 | } | |
213 | } | |
214 | ||
215 | /* Internal register function - just handle k*probes and flags */ | |
216 | static int __register_trace_probe(struct trace_probe *tp) | |
217 | { | |
218 | int i, ret; | |
219 | ||
220 | if (trace_probe_is_registered(tp)) | |
221 | return -EINVAL; | |
222 | ||
223 | for (i = 0; i < tp->nr_args; i++) | |
224 | traceprobe_update_arg(&tp->args[i]); | |
225 | ||
226 | /* Set/clear disabled flag according to tp->flag */ | |
227 | if (trace_probe_is_enabled(tp)) | |
228 | tp->rp.kp.flags &= ~KPROBE_FLAG_DISABLED; | |
229 | else | |
230 | tp->rp.kp.flags |= KPROBE_FLAG_DISABLED; | |
231 | ||
232 | if (trace_probe_is_return(tp)) | |
233 | ret = register_kretprobe(&tp->rp); | |
234 | else | |
235 | ret = register_kprobe(&tp->rp.kp); | |
236 | ||
237 | if (ret == 0) | |
238 | tp->flags |= TP_FLAG_REGISTERED; | |
239 | else { | |
240 | pr_warning("Could not insert probe at %s+%lu: %d\n", | |
241 | trace_probe_symbol(tp), trace_probe_offset(tp), ret); | |
242 | if (ret == -ENOENT && trace_probe_is_on_module(tp)) { | |
243 | pr_warning("This probe might be able to register after" | |
244 | "target module is loaded. Continue.\n"); | |
245 | ret = 0; | |
246 | } else if (ret == -EILSEQ) { | |
247 | pr_warning("Probing address(0x%p) is not an " | |
248 | "instruction boundary.\n", | |
249 | tp->rp.kp.addr); | |
250 | ret = -EINVAL; | |
251 | } | |
252 | } | |
253 | ||
254 | return ret; | |
255 | } | |
256 | ||
257 | /* Internal unregister function - just handle k*probes and flags */ | |
258 | static void __unregister_trace_probe(struct trace_probe *tp) | |
259 | { | |
260 | if (trace_probe_is_registered(tp)) { | |
261 | if (trace_probe_is_return(tp)) | |
262 | unregister_kretprobe(&tp->rp); | |
263 | else | |
264 | unregister_kprobe(&tp->rp.kp); | |
265 | tp->flags &= ~TP_FLAG_REGISTERED; | |
266 | /* Cleanup kprobe for reuse */ | |
267 | if (tp->rp.kp.symbol_name) | |
268 | tp->rp.kp.addr = NULL; | |
269 | } | |
270 | } | |
271 | ||
272 | /* Unregister a trace_probe and probe_event: call with locking probe_lock */ | |
273 | static int unregister_trace_probe(struct trace_probe *tp) | |
274 | { | |
275 | /* Enabled event can not be unregistered */ | |
276 | if (trace_probe_is_enabled(tp)) | |
277 | return -EBUSY; | |
278 | ||
279 | __unregister_trace_probe(tp); | |
280 | list_del(&tp->list); | |
281 | unregister_probe_event(tp); | |
282 | ||
283 | return 0; | |
284 | } | |
285 | ||
286 | /* Register a trace_probe and probe_event */ | |
287 | static int register_trace_probe(struct trace_probe *tp) | |
288 | { | |
289 | struct trace_probe *old_tp; | |
290 | int ret; | |
291 | ||
292 | mutex_lock(&probe_lock); | |
293 | ||
294 | /* Delete old (same name) event if exist */ | |
295 | old_tp = find_trace_probe(tp->call.name, tp->call.class->system); | |
296 | if (old_tp) { | |
297 | ret = unregister_trace_probe(old_tp); | |
298 | if (ret < 0) | |
299 | goto end; | |
300 | free_trace_probe(old_tp); | |
301 | } | |
302 | ||
303 | /* Register new event */ | |
304 | ret = register_probe_event(tp); | |
305 | if (ret) { | |
306 | pr_warning("Failed to register probe event(%d)\n", ret); | |
307 | goto end; | |
308 | } | |
309 | ||
310 | /* Register k*probe */ | |
311 | ret = __register_trace_probe(tp); | |
312 | if (ret < 0) | |
313 | unregister_probe_event(tp); | |
314 | else | |
315 | list_add_tail(&tp->list, &probe_list); | |
316 | ||
317 | end: | |
318 | mutex_unlock(&probe_lock); | |
319 | return ret; | |
320 | } | |
321 | ||
322 | /* Module notifier call back, checking event on the module */ | |
323 | static int trace_probe_module_callback(struct notifier_block *nb, | |
324 | unsigned long val, void *data) | |
325 | { | |
326 | struct module *mod = data; | |
327 | struct trace_probe *tp; | |
328 | int ret; | |
329 | ||
330 | if (val != MODULE_STATE_COMING) | |
331 | return NOTIFY_DONE; | |
332 | ||
333 | /* Update probes on coming module */ | |
334 | mutex_lock(&probe_lock); | |
335 | list_for_each_entry(tp, &probe_list, list) { | |
336 | if (trace_probe_within_module(tp, mod)) { | |
337 | /* Don't need to check busy - this should have gone. */ | |
338 | __unregister_trace_probe(tp); | |
339 | ret = __register_trace_probe(tp); | |
340 | if (ret) | |
341 | pr_warning("Failed to re-register probe %s on" | |
342 | "%s: %d\n", | |
343 | tp->call.name, mod->name, ret); | |
344 | } | |
345 | } | |
346 | mutex_unlock(&probe_lock); | |
347 | ||
348 | return NOTIFY_DONE; | |
349 | } | |
350 | ||
351 | static struct notifier_block trace_probe_module_nb = { | |
352 | .notifier_call = trace_probe_module_callback, | |
353 | .priority = 1 /* Invoked after kprobe module callback */ | |
354 | }; | |
355 | ||
356 | static int create_trace_probe(int argc, char **argv) | |
357 | { | |
358 | /* | |
359 | * Argument syntax: | |
360 | * - Add kprobe: p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS] | |
361 | * - Add kretprobe: r[:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS] | |
362 | * Fetch args: | |
363 | * $retval : fetch return value | |
364 | * $stack : fetch stack address | |
365 | * $stackN : fetch Nth of stack (N:0-) | |
366 | * @ADDR : fetch memory at ADDR (ADDR should be in kernel) | |
367 | * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol) | |
368 | * %REG : fetch register REG | |
369 | * Dereferencing memory fetch: | |
370 | * +|-offs(ARG) : fetch memory at ARG +|- offs address. | |
371 | * Alias name of args: | |
372 | * NAME=FETCHARG : set NAME as alias of FETCHARG. | |
373 | * Type of args: | |
374 | * FETCHARG:TYPE : use TYPE instead of unsigned long. | |
375 | */ | |
376 | struct trace_probe *tp; | |
377 | int i, ret = 0; | |
378 | bool is_return = false, is_delete = false; | |
379 | char *symbol = NULL, *event = NULL, *group = NULL; | |
380 | char *arg; | |
381 | unsigned long offset = 0; | |
382 | void *addr = NULL; | |
383 | char buf[MAX_EVENT_NAME_LEN]; | |
384 | ||
385 | /* argc must be >= 1 */ | |
386 | if (argv[0][0] == 'p') | |
387 | is_return = false; | |
388 | else if (argv[0][0] == 'r') | |
389 | is_return = true; | |
390 | else if (argv[0][0] == '-') | |
391 | is_delete = true; | |
392 | else { | |
393 | pr_info("Probe definition must be started with 'p', 'r' or" | |
394 | " '-'.\n"); | |
395 | return -EINVAL; | |
396 | } | |
397 | ||
398 | if (argv[0][1] == ':') { | |
399 | event = &argv[0][2]; | |
400 | if (strchr(event, '/')) { | |
401 | group = event; | |
402 | event = strchr(group, '/') + 1; | |
403 | event[-1] = '\0'; | |
404 | if (strlen(group) == 0) { | |
405 | pr_info("Group name is not specified\n"); | |
406 | return -EINVAL; | |
407 | } | |
408 | } | |
409 | if (strlen(event) == 0) { | |
410 | pr_info("Event name is not specified\n"); | |
411 | return -EINVAL; | |
412 | } | |
413 | } | |
414 | if (!group) | |
415 | group = KPROBE_EVENT_SYSTEM; | |
416 | ||
417 | if (is_delete) { | |
418 | if (!event) { | |
419 | pr_info("Delete command needs an event name.\n"); | |
420 | return -EINVAL; | |
421 | } | |
422 | mutex_lock(&probe_lock); | |
423 | tp = find_trace_probe(event, group); | |
424 | if (!tp) { | |
425 | mutex_unlock(&probe_lock); | |
426 | pr_info("Event %s/%s doesn't exist.\n", group, event); | |
427 | return -ENOENT; | |
428 | } | |
429 | /* delete an event */ | |
430 | ret = unregister_trace_probe(tp); | |
431 | if (ret == 0) | |
432 | free_trace_probe(tp); | |
433 | mutex_unlock(&probe_lock); | |
434 | return ret; | |
435 | } | |
436 | ||
437 | if (argc < 2) { | |
438 | pr_info("Probe point is not specified.\n"); | |
439 | return -EINVAL; | |
440 | } | |
441 | if (isdigit(argv[1][0])) { | |
442 | if (is_return) { | |
443 | pr_info("Return probe point must be a symbol.\n"); | |
444 | return -EINVAL; | |
445 | } | |
446 | /* an address specified */ | |
447 | ret = strict_strtoul(&argv[1][0], 0, (unsigned long *)&addr); | |
448 | if (ret) { | |
449 | pr_info("Failed to parse address.\n"); | |
450 | return ret; | |
451 | } | |
452 | } else { | |
453 | /* a symbol specified */ | |
454 | symbol = argv[1]; | |
455 | /* TODO: support .init module functions */ | |
456 | ret = traceprobe_split_symbol_offset(symbol, &offset); | |
457 | if (ret) { | |
458 | pr_info("Failed to parse symbol.\n"); | |
459 | return ret; | |
460 | } | |
461 | if (offset && is_return) { | |
462 | pr_info("Return probe must be used without offset.\n"); | |
463 | return -EINVAL; | |
464 | } | |
465 | } | |
466 | argc -= 2; argv += 2; | |
467 | ||
468 | /* setup a probe */ | |
469 | if (!event) { | |
470 | /* Make a new event name */ | |
471 | if (symbol) | |
472 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld", | |
473 | is_return ? 'r' : 'p', symbol, offset); | |
474 | else | |
475 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p", | |
476 | is_return ? 'r' : 'p', addr); | |
477 | event = buf; | |
478 | } | |
479 | tp = alloc_trace_probe(group, event, addr, symbol, offset, argc, | |
480 | is_return); | |
481 | if (IS_ERR(tp)) { | |
482 | pr_info("Failed to allocate trace_probe.(%d)\n", | |
483 | (int)PTR_ERR(tp)); | |
484 | return PTR_ERR(tp); | |
485 | } | |
486 | ||
487 | /* parse arguments */ | |
488 | ret = 0; | |
489 | for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { | |
490 | /* Increment count for freeing args in error case */ | |
491 | tp->nr_args++; | |
492 | ||
493 | /* Parse argument name */ | |
494 | arg = strchr(argv[i], '='); | |
495 | if (arg) { | |
496 | *arg++ = '\0'; | |
497 | tp->args[i].name = kstrdup(argv[i], GFP_KERNEL); | |
498 | } else { | |
499 | arg = argv[i]; | |
500 | /* If argument name is omitted, set "argN" */ | |
501 | snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1); | |
502 | tp->args[i].name = kstrdup(buf, GFP_KERNEL); | |
503 | } | |
504 | ||
505 | if (!tp->args[i].name) { | |
506 | pr_info("Failed to allocate argument[%d] name.\n", i); | |
507 | ret = -ENOMEM; | |
508 | goto error; | |
509 | } | |
510 | ||
511 | if (!is_good_name(tp->args[i].name)) { | |
512 | pr_info("Invalid argument[%d] name: %s\n", | |
513 | i, tp->args[i].name); | |
514 | ret = -EINVAL; | |
515 | goto error; | |
516 | } | |
517 | ||
518 | if (traceprobe_conflict_field_name(tp->args[i].name, | |
519 | tp->args, i)) { | |
520 | pr_info("Argument[%d] name '%s' conflicts with " | |
521 | "another field.\n", i, argv[i]); | |
522 | ret = -EINVAL; | |
523 | goto error; | |
524 | } | |
525 | ||
526 | /* Parse fetch argument */ | |
527 | ret = traceprobe_parse_probe_arg(arg, &tp->size, &tp->args[i], | |
528 | is_return, true); | |
529 | if (ret) { | |
530 | pr_info("Parse error at argument[%d]. (%d)\n", i, ret); | |
531 | goto error; | |
532 | } | |
533 | } | |
534 | ||
535 | ret = register_trace_probe(tp); | |
536 | if (ret) | |
537 | goto error; | |
538 | return 0; | |
539 | ||
540 | error: | |
541 | free_trace_probe(tp); | |
542 | return ret; | |
543 | } | |
544 | ||
545 | static int release_all_trace_probes(void) | |
546 | { | |
547 | struct trace_probe *tp; | |
548 | int ret = 0; | |
549 | ||
550 | mutex_lock(&probe_lock); | |
551 | /* Ensure no probe is in use. */ | |
552 | list_for_each_entry(tp, &probe_list, list) | |
553 | if (trace_probe_is_enabled(tp)) { | |
554 | ret = -EBUSY; | |
555 | goto end; | |
556 | } | |
557 | /* TODO: Use batch unregistration */ | |
558 | while (!list_empty(&probe_list)) { | |
559 | tp = list_entry(probe_list.next, struct trace_probe, list); | |
560 | unregister_trace_probe(tp); | |
561 | free_trace_probe(tp); | |
562 | } | |
563 | ||
564 | end: | |
565 | mutex_unlock(&probe_lock); | |
566 | ||
567 | return ret; | |
568 | } | |
569 | ||
570 | /* Probes listing interfaces */ | |
571 | static void *probes_seq_start(struct seq_file *m, loff_t *pos) | |
572 | { | |
573 | mutex_lock(&probe_lock); | |
574 | return seq_list_start(&probe_list, *pos); | |
575 | } | |
576 | ||
577 | static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos) | |
578 | { | |
579 | return seq_list_next(v, &probe_list, pos); | |
580 | } | |
581 | ||
582 | static void probes_seq_stop(struct seq_file *m, void *v) | |
583 | { | |
584 | mutex_unlock(&probe_lock); | |
585 | } | |
586 | ||
587 | static int probes_seq_show(struct seq_file *m, void *v) | |
588 | { | |
589 | struct trace_probe *tp = v; | |
590 | int i; | |
591 | ||
592 | seq_printf(m, "%c", trace_probe_is_return(tp) ? 'r' : 'p'); | |
593 | seq_printf(m, ":%s/%s", tp->call.class->system, tp->call.name); | |
594 | ||
595 | if (!tp->symbol) | |
596 | seq_printf(m, " 0x%p", tp->rp.kp.addr); | |
597 | else if (tp->rp.kp.offset) | |
598 | seq_printf(m, " %s+%u", trace_probe_symbol(tp), | |
599 | tp->rp.kp.offset); | |
600 | else | |
601 | seq_printf(m, " %s", trace_probe_symbol(tp)); | |
602 | ||
603 | for (i = 0; i < tp->nr_args; i++) | |
604 | seq_printf(m, " %s=%s", tp->args[i].name, tp->args[i].comm); | |
605 | seq_printf(m, "\n"); | |
606 | ||
607 | return 0; | |
608 | } | |
609 | ||
610 | static const struct seq_operations probes_seq_op = { | |
611 | .start = probes_seq_start, | |
612 | .next = probes_seq_next, | |
613 | .stop = probes_seq_stop, | |
614 | .show = probes_seq_show | |
615 | }; | |
616 | ||
617 | static int probes_open(struct inode *inode, struct file *file) | |
618 | { | |
619 | int ret; | |
620 | ||
621 | if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { | |
622 | ret = release_all_trace_probes(); | |
623 | if (ret < 0) | |
624 | return ret; | |
625 | } | |
626 | ||
627 | return seq_open(file, &probes_seq_op); | |
628 | } | |
629 | ||
630 | static ssize_t probes_write(struct file *file, const char __user *buffer, | |
631 | size_t count, loff_t *ppos) | |
632 | { | |
633 | return traceprobe_probes_write(file, buffer, count, ppos, | |
634 | create_trace_probe); | |
635 | } | |
636 | ||
637 | static const struct file_operations kprobe_events_ops = { | |
638 | .owner = THIS_MODULE, | |
639 | .open = probes_open, | |
640 | .read = seq_read, | |
641 | .llseek = seq_lseek, | |
642 | .release = seq_release, | |
643 | .write = probes_write, | |
644 | }; | |
645 | ||
646 | /* Probes profiling interfaces */ | |
647 | static int probes_profile_seq_show(struct seq_file *m, void *v) | |
648 | { | |
649 | struct trace_probe *tp = v; | |
650 | ||
651 | seq_printf(m, " %-44s %15lu %15lu\n", tp->call.name, tp->nhit, | |
652 | tp->rp.kp.nmissed); | |
653 | ||
654 | return 0; | |
655 | } | |
656 | ||
657 | static const struct seq_operations profile_seq_op = { | |
658 | .start = probes_seq_start, | |
659 | .next = probes_seq_next, | |
660 | .stop = probes_seq_stop, | |
661 | .show = probes_profile_seq_show | |
662 | }; | |
663 | ||
664 | static int profile_open(struct inode *inode, struct file *file) | |
665 | { | |
666 | return seq_open(file, &profile_seq_op); | |
667 | } | |
668 | ||
669 | static const struct file_operations kprobe_profile_ops = { | |
670 | .owner = THIS_MODULE, | |
671 | .open = profile_open, | |
672 | .read = seq_read, | |
673 | .llseek = seq_lseek, | |
674 | .release = seq_release, | |
675 | }; | |
676 | ||
677 | /* Sum up total data length for dynamic arraies (strings) */ | |
678 | static __kprobes int __get_data_size(struct trace_probe *tp, | |
679 | struct pt_regs *regs) | |
680 | { | |
681 | int i, ret = 0; | |
682 | u32 len; | |
683 | ||
684 | for (i = 0; i < tp->nr_args; i++) | |
685 | if (unlikely(tp->args[i].fetch_size.fn)) { | |
686 | call_fetch(&tp->args[i].fetch_size, regs, &len); | |
687 | ret += len; | |
688 | } | |
689 | ||
690 | return ret; | |
691 | } | |
692 | ||
693 | /* Store the value of each argument */ | |
694 | static __kprobes void store_trace_args(int ent_size, struct trace_probe *tp, | |
695 | struct pt_regs *regs, | |
696 | u8 *data, int maxlen) | |
697 | { | |
698 | int i; | |
699 | u32 end = tp->size; | |
700 | u32 *dl; /* Data (relative) location */ | |
701 | ||
702 | for (i = 0; i < tp->nr_args; i++) { | |
703 | if (unlikely(tp->args[i].fetch_size.fn)) { | |
704 | /* | |
705 | * First, we set the relative location and | |
706 | * maximum data length to *dl | |
707 | */ | |
708 | dl = (u32 *)(data + tp->args[i].offset); | |
709 | *dl = make_data_rloc(maxlen, end - tp->args[i].offset); | |
710 | /* Then try to fetch string or dynamic array data */ | |
711 | call_fetch(&tp->args[i].fetch, regs, dl); | |
712 | /* Reduce maximum length */ | |
713 | end += get_rloc_len(*dl); | |
714 | maxlen -= get_rloc_len(*dl); | |
715 | /* Trick here, convert data_rloc to data_loc */ | |
716 | *dl = convert_rloc_to_loc(*dl, | |
717 | ent_size + tp->args[i].offset); | |
718 | } else | |
719 | /* Just fetching data normally */ | |
720 | call_fetch(&tp->args[i].fetch, regs, | |
721 | data + tp->args[i].offset); | |
722 | } | |
723 | } | |
724 | ||
725 | /* Kprobe handler */ | |
726 | static __kprobes void kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs) | |
727 | { | |
728 | struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp); | |
729 | struct kprobe_trace_entry_head *entry; | |
730 | struct ring_buffer_event *event; | |
731 | struct ring_buffer *buffer; | |
732 | int size, dsize, pc; | |
733 | unsigned long irq_flags; | |
734 | struct ftrace_event_call *call = &tp->call; | |
735 | ||
736 | tp->nhit++; | |
737 | ||
738 | local_save_flags(irq_flags); | |
739 | pc = preempt_count(); | |
740 | ||
741 | dsize = __get_data_size(tp, regs); | |
742 | size = sizeof(*entry) + tp->size + dsize; | |
743 | ||
744 | event = trace_current_buffer_lock_reserve(&buffer, call->event.type, | |
745 | size, irq_flags, pc); | |
746 | if (!event) | |
747 | return; | |
748 | ||
749 | entry = ring_buffer_event_data(event); | |
750 | entry->ip = (unsigned long)kp->addr; | |
751 | store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize); | |
752 | ||
753 | if (!filter_current_check_discard(buffer, call, entry, event)) | |
754 | trace_nowake_buffer_unlock_commit_regs(buffer, event, | |
755 | irq_flags, pc, regs); | |
756 | } | |
757 | ||
758 | /* Kretprobe handler */ | |
759 | static __kprobes void kretprobe_trace_func(struct kretprobe_instance *ri, | |
760 | struct pt_regs *regs) | |
761 | { | |
762 | struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp); | |
763 | struct kretprobe_trace_entry_head *entry; | |
764 | struct ring_buffer_event *event; | |
765 | struct ring_buffer *buffer; | |
766 | int size, pc, dsize; | |
767 | unsigned long irq_flags; | |
768 | struct ftrace_event_call *call = &tp->call; | |
769 | ||
770 | local_save_flags(irq_flags); | |
771 | pc = preempt_count(); | |
772 | ||
773 | dsize = __get_data_size(tp, regs); | |
774 | size = sizeof(*entry) + tp->size + dsize; | |
775 | ||
776 | event = trace_current_buffer_lock_reserve(&buffer, call->event.type, | |
777 | size, irq_flags, pc); | |
778 | if (!event) | |
779 | return; | |
780 | ||
781 | entry = ring_buffer_event_data(event); | |
782 | entry->func = (unsigned long)tp->rp.kp.addr; | |
783 | entry->ret_ip = (unsigned long)ri->ret_addr; | |
784 | store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize); | |
785 | ||
786 | if (!filter_current_check_discard(buffer, call, entry, event)) | |
787 | trace_nowake_buffer_unlock_commit_regs(buffer, event, | |
788 | irq_flags, pc, regs); | |
789 | } | |
790 | ||
791 | /* Event entry printers */ | |
792 | enum print_line_t | |
793 | print_kprobe_event(struct trace_iterator *iter, int flags, | |
794 | struct trace_event *event) | |
795 | { | |
796 | struct kprobe_trace_entry_head *field; | |
797 | struct trace_seq *s = &iter->seq; | |
798 | struct trace_probe *tp; | |
799 | u8 *data; | |
800 | int i; | |
801 | ||
802 | field = (struct kprobe_trace_entry_head *)iter->ent; | |
803 | tp = container_of(event, struct trace_probe, call.event); | |
804 | ||
805 | if (!trace_seq_printf(s, "%s: (", tp->call.name)) | |
806 | goto partial; | |
807 | ||
808 | if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) | |
809 | goto partial; | |
810 | ||
811 | if (!trace_seq_puts(s, ")")) | |
812 | goto partial; | |
813 | ||
814 | data = (u8 *)&field[1]; | |
815 | for (i = 0; i < tp->nr_args; i++) | |
816 | if (!tp->args[i].type->print(s, tp->args[i].name, | |
817 | data + tp->args[i].offset, field)) | |
818 | goto partial; | |
819 | ||
820 | if (!trace_seq_puts(s, "\n")) | |
821 | goto partial; | |
822 | ||
823 | return TRACE_TYPE_HANDLED; | |
824 | partial: | |
825 | return TRACE_TYPE_PARTIAL_LINE; | |
826 | } | |
827 | ||
828 | enum print_line_t | |
829 | print_kretprobe_event(struct trace_iterator *iter, int flags, | |
830 | struct trace_event *event) | |
831 | { | |
832 | struct kretprobe_trace_entry_head *field; | |
833 | struct trace_seq *s = &iter->seq; | |
834 | struct trace_probe *tp; | |
835 | u8 *data; | |
836 | int i; | |
837 | ||
838 | field = (struct kretprobe_trace_entry_head *)iter->ent; | |
839 | tp = container_of(event, struct trace_probe, call.event); | |
840 | ||
841 | if (!trace_seq_printf(s, "%s: (", tp->call.name)) | |
842 | goto partial; | |
843 | ||
844 | if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET)) | |
845 | goto partial; | |
846 | ||
847 | if (!trace_seq_puts(s, " <- ")) | |
848 | goto partial; | |
849 | ||
850 | if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET)) | |
851 | goto partial; | |
852 | ||
853 | if (!trace_seq_puts(s, ")")) | |
854 | goto partial; | |
855 | ||
856 | data = (u8 *)&field[1]; | |
857 | for (i = 0; i < tp->nr_args; i++) | |
858 | if (!tp->args[i].type->print(s, tp->args[i].name, | |
859 | data + tp->args[i].offset, field)) | |
860 | goto partial; | |
861 | ||
862 | if (!trace_seq_puts(s, "\n")) | |
863 | goto partial; | |
864 | ||
865 | return TRACE_TYPE_HANDLED; | |
866 | partial: | |
867 | return TRACE_TYPE_PARTIAL_LINE; | |
868 | } | |
869 | ||
870 | ||
871 | static int kprobe_event_define_fields(struct ftrace_event_call *event_call) | |
872 | { | |
873 | int ret, i; | |
874 | struct kprobe_trace_entry_head field; | |
875 | struct trace_probe *tp = (struct trace_probe *)event_call->data; | |
876 | ||
877 | DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); | |
878 | /* Set argument names as fields */ | |
879 | for (i = 0; i < tp->nr_args; i++) { | |
880 | ret = trace_define_field(event_call, tp->args[i].type->fmttype, | |
881 | tp->args[i].name, | |
882 | sizeof(field) + tp->args[i].offset, | |
883 | tp->args[i].type->size, | |
884 | tp->args[i].type->is_signed, | |
885 | FILTER_OTHER); | |
886 | if (ret) | |
887 | return ret; | |
888 | } | |
889 | return 0; | |
890 | } | |
891 | ||
892 | static int kretprobe_event_define_fields(struct ftrace_event_call *event_call) | |
893 | { | |
894 | int ret, i; | |
895 | struct kretprobe_trace_entry_head field; | |
896 | struct trace_probe *tp = (struct trace_probe *)event_call->data; | |
897 | ||
898 | DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0); | |
899 | DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0); | |
900 | /* Set argument names as fields */ | |
901 | for (i = 0; i < tp->nr_args; i++) { | |
902 | ret = trace_define_field(event_call, tp->args[i].type->fmttype, | |
903 | tp->args[i].name, | |
904 | sizeof(field) + tp->args[i].offset, | |
905 | tp->args[i].type->size, | |
906 | tp->args[i].type->is_signed, | |
907 | FILTER_OTHER); | |
908 | if (ret) | |
909 | return ret; | |
910 | } | |
911 | return 0; | |
912 | } | |
913 | ||
914 | static int __set_print_fmt(struct trace_probe *tp, char *buf, int len) | |
915 | { | |
916 | int i; | |
917 | int pos = 0; | |
918 | ||
919 | const char *fmt, *arg; | |
920 | ||
921 | if (!trace_probe_is_return(tp)) { | |
922 | fmt = "(%lx)"; | |
923 | arg = "REC->" FIELD_STRING_IP; | |
924 | } else { | |
925 | fmt = "(%lx <- %lx)"; | |
926 | arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP; | |
927 | } | |
928 | ||
929 | /* When len=0, we just calculate the needed length */ | |
930 | #define LEN_OR_ZERO (len ? len - pos : 0) | |
931 | ||
932 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt); | |
933 | ||
934 | for (i = 0; i < tp->nr_args; i++) { | |
935 | pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s", | |
936 | tp->args[i].name, tp->args[i].type->fmt); | |
937 | } | |
938 | ||
939 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg); | |
940 | ||
941 | for (i = 0; i < tp->nr_args; i++) { | |
942 | if (strcmp(tp->args[i].type->name, "string") == 0) | |
943 | pos += snprintf(buf + pos, LEN_OR_ZERO, | |
944 | ", __get_str(%s)", | |
945 | tp->args[i].name); | |
946 | else | |
947 | pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s", | |
948 | tp->args[i].name); | |
949 | } | |
950 | ||
951 | #undef LEN_OR_ZERO | |
952 | ||
953 | /* return the length of print_fmt */ | |
954 | return pos; | |
955 | } | |
956 | ||
957 | static int set_print_fmt(struct trace_probe *tp) | |
958 | { | |
959 | int len; | |
960 | char *print_fmt; | |
961 | ||
962 | /* First: called with 0 length to calculate the needed length */ | |
963 | len = __set_print_fmt(tp, NULL, 0); | |
964 | print_fmt = kmalloc(len + 1, GFP_KERNEL); | |
965 | if (!print_fmt) | |
966 | return -ENOMEM; | |
967 | ||
968 | /* Second: actually write the @print_fmt */ | |
969 | __set_print_fmt(tp, print_fmt, len + 1); | |
970 | tp->call.print_fmt = print_fmt; | |
971 | ||
972 | return 0; | |
973 | } | |
974 | ||
975 | #ifdef CONFIG_PERF_EVENTS | |
976 | ||
977 | /* Kprobe profile handler */ | |
978 | static __kprobes void kprobe_perf_func(struct kprobe *kp, | |
979 | struct pt_regs *regs) | |
980 | { | |
981 | struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp); | |
982 | struct ftrace_event_call *call = &tp->call; | |
983 | struct kprobe_trace_entry_head *entry; | |
984 | struct hlist_head *head; | |
985 | int size, __size, dsize; | |
986 | int rctx; | |
987 | ||
988 | dsize = __get_data_size(tp, regs); | |
989 | __size = sizeof(*entry) + tp->size + dsize; | |
990 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); | |
991 | size -= sizeof(u32); | |
992 | if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, | |
993 | "profile buffer not large enough")) | |
994 | return; | |
995 | ||
996 | entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx); | |
997 | if (!entry) | |
998 | return; | |
999 | ||
1000 | entry->ip = (unsigned long)kp->addr; | |
1001 | memset(&entry[1], 0, dsize); | |
1002 | store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize); | |
1003 | ||
1004 | head = this_cpu_ptr(call->perf_events); | |
1005 | perf_trace_buf_submit(entry, size, rctx, | |
1006 | entry->ip, 1, regs, head, NULL); | |
1007 | } | |
1008 | ||
1009 | /* Kretprobe profile handler */ | |
1010 | static __kprobes void kretprobe_perf_func(struct kretprobe_instance *ri, | |
1011 | struct pt_regs *regs) | |
1012 | { | |
1013 | struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp); | |
1014 | struct ftrace_event_call *call = &tp->call; | |
1015 | struct kretprobe_trace_entry_head *entry; | |
1016 | struct hlist_head *head; | |
1017 | int size, __size, dsize; | |
1018 | int rctx; | |
1019 | ||
1020 | dsize = __get_data_size(tp, regs); | |
1021 | __size = sizeof(*entry) + tp->size + dsize; | |
1022 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); | |
1023 | size -= sizeof(u32); | |
1024 | if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, | |
1025 | "profile buffer not large enough")) | |
1026 | return; | |
1027 | ||
1028 | entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx); | |
1029 | if (!entry) | |
1030 | return; | |
1031 | ||
1032 | entry->func = (unsigned long)tp->rp.kp.addr; | |
1033 | entry->ret_ip = (unsigned long)ri->ret_addr; | |
1034 | store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize); | |
1035 | ||
1036 | head = this_cpu_ptr(call->perf_events); | |
1037 | perf_trace_buf_submit(entry, size, rctx, | |
1038 | entry->ret_ip, 1, regs, head, NULL); | |
1039 | } | |
1040 | #endif /* CONFIG_PERF_EVENTS */ | |
1041 | ||
1042 | static __kprobes | |
1043 | int kprobe_register(struct ftrace_event_call *event, | |
1044 | enum trace_reg type, void *data) | |
1045 | { | |
1046 | struct trace_probe *tp = (struct trace_probe *)event->data; | |
1047 | ||
1048 | switch (type) { | |
1049 | case TRACE_REG_REGISTER: | |
1050 | return enable_trace_probe(tp, TP_FLAG_TRACE); | |
1051 | case TRACE_REG_UNREGISTER: | |
1052 | disable_trace_probe(tp, TP_FLAG_TRACE); | |
1053 | return 0; | |
1054 | ||
1055 | #ifdef CONFIG_PERF_EVENTS | |
1056 | case TRACE_REG_PERF_REGISTER: | |
1057 | return enable_trace_probe(tp, TP_FLAG_PROFILE); | |
1058 | case TRACE_REG_PERF_UNREGISTER: | |
1059 | disable_trace_probe(tp, TP_FLAG_PROFILE); | |
1060 | return 0; | |
1061 | case TRACE_REG_PERF_OPEN: | |
1062 | case TRACE_REG_PERF_CLOSE: | |
1063 | case TRACE_REG_PERF_ADD: | |
1064 | case TRACE_REG_PERF_DEL: | |
1065 | return 0; | |
1066 | #endif | |
1067 | } | |
1068 | return 0; | |
1069 | } | |
1070 | ||
1071 | static __kprobes | |
1072 | int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) | |
1073 | { | |
1074 | struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp); | |
1075 | ||
1076 | if (tp->flags & TP_FLAG_TRACE) | |
1077 | kprobe_trace_func(kp, regs); | |
1078 | #ifdef CONFIG_PERF_EVENTS | |
1079 | if (tp->flags & TP_FLAG_PROFILE) | |
1080 | kprobe_perf_func(kp, regs); | |
1081 | #endif | |
1082 | return 0; /* We don't tweek kernel, so just return 0 */ | |
1083 | } | |
1084 | ||
1085 | static __kprobes | |
1086 | int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) | |
1087 | { | |
1088 | struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp); | |
1089 | ||
1090 | if (tp->flags & TP_FLAG_TRACE) | |
1091 | kretprobe_trace_func(ri, regs); | |
1092 | #ifdef CONFIG_PERF_EVENTS | |
1093 | if (tp->flags & TP_FLAG_PROFILE) | |
1094 | kretprobe_perf_func(ri, regs); | |
1095 | #endif | |
1096 | return 0; /* We don't tweek kernel, so just return 0 */ | |
1097 | } | |
1098 | ||
1099 | static struct trace_event_functions kretprobe_funcs = { | |
1100 | .trace = print_kretprobe_event | |
1101 | }; | |
1102 | ||
1103 | static struct trace_event_functions kprobe_funcs = { | |
1104 | .trace = print_kprobe_event | |
1105 | }; | |
1106 | ||
1107 | static int register_probe_event(struct trace_probe *tp) | |
1108 | { | |
1109 | struct ftrace_event_call *call = &tp->call; | |
1110 | int ret; | |
1111 | ||
1112 | /* Initialize ftrace_event_call */ | |
1113 | INIT_LIST_HEAD(&call->class->fields); | |
1114 | if (trace_probe_is_return(tp)) { | |
1115 | call->event.funcs = &kretprobe_funcs; | |
1116 | call->class->define_fields = kretprobe_event_define_fields; | |
1117 | } else { | |
1118 | call->event.funcs = &kprobe_funcs; | |
1119 | call->class->define_fields = kprobe_event_define_fields; | |
1120 | } | |
1121 | if (set_print_fmt(tp) < 0) | |
1122 | return -ENOMEM; | |
1123 | ret = register_ftrace_event(&call->event); | |
1124 | if (!ret) { | |
1125 | kfree(call->print_fmt); | |
1126 | return -ENODEV; | |
1127 | } | |
1128 | call->flags = 0; | |
1129 | call->class->reg = kprobe_register; | |
1130 | call->data = tp; | |
1131 | ret = trace_add_event_call(call); | |
1132 | if (ret) { | |
1133 | pr_info("Failed to register kprobe event: %s\n", call->name); | |
1134 | kfree(call->print_fmt); | |
1135 | unregister_ftrace_event(&call->event); | |
1136 | } | |
1137 | return ret; | |
1138 | } | |
1139 | ||
1140 | static void unregister_probe_event(struct trace_probe *tp) | |
1141 | { | |
1142 | /* tp->event is unregistered in trace_remove_event_call() */ | |
1143 | trace_remove_event_call(&tp->call); | |
1144 | kfree(tp->call.print_fmt); | |
1145 | } | |
1146 | ||
1147 | /* Make a debugfs interface for controlling probe points */ | |
1148 | static __init int init_kprobe_trace(void) | |
1149 | { | |
1150 | struct dentry *d_tracer; | |
1151 | struct dentry *entry; | |
1152 | ||
1153 | if (register_module_notifier(&trace_probe_module_nb)) | |
1154 | return -EINVAL; | |
1155 | ||
1156 | d_tracer = tracing_init_dentry(); | |
1157 | if (!d_tracer) | |
1158 | return 0; | |
1159 | ||
1160 | entry = debugfs_create_file("kprobe_events", 0644, d_tracer, | |
1161 | NULL, &kprobe_events_ops); | |
1162 | ||
1163 | /* Event list interface */ | |
1164 | if (!entry) | |
1165 | pr_warning("Could not create debugfs " | |
1166 | "'kprobe_events' entry\n"); | |
1167 | ||
1168 | /* Profile interface */ | |
1169 | entry = debugfs_create_file("kprobe_profile", 0444, d_tracer, | |
1170 | NULL, &kprobe_profile_ops); | |
1171 | ||
1172 | if (!entry) | |
1173 | pr_warning("Could not create debugfs " | |
1174 | "'kprobe_profile' entry\n"); | |
1175 | return 0; | |
1176 | } | |
1177 | fs_initcall(init_kprobe_trace); | |
1178 | ||
1179 | ||
1180 | #ifdef CONFIG_FTRACE_STARTUP_TEST | |
1181 | ||
1182 | /* | |
1183 | * The "__used" keeps gcc from removing the function symbol | |
1184 | * from the kallsyms table. | |
1185 | */ | |
1186 | static __used int kprobe_trace_selftest_target(int a1, int a2, int a3, | |
1187 | int a4, int a5, int a6) | |
1188 | { | |
1189 | return a1 + a2 + a3 + a4 + a5 + a6; | |
1190 | } | |
1191 | ||
1192 | static __init int kprobe_trace_self_tests_init(void) | |
1193 | { | |
1194 | int ret, warn = 0; | |
1195 | int (*target)(int, int, int, int, int, int); | |
1196 | struct trace_probe *tp; | |
1197 | ||
1198 | target = kprobe_trace_selftest_target; | |
1199 | ||
1200 | pr_info("Testing kprobe tracing: "); | |
1201 | ||
1202 | ret = traceprobe_command("p:testprobe kprobe_trace_selftest_target " | |
1203 | "$stack $stack0 +0($stack)", | |
1204 | create_trace_probe); | |
1205 | if (WARN_ON_ONCE(ret)) { | |
1206 | pr_warning("error on probing function entry.\n"); | |
1207 | warn++; | |
1208 | } else { | |
1209 | /* Enable trace point */ | |
1210 | tp = find_trace_probe("testprobe", KPROBE_EVENT_SYSTEM); | |
1211 | if (WARN_ON_ONCE(tp == NULL)) { | |
1212 | pr_warning("error on getting new probe.\n"); | |
1213 | warn++; | |
1214 | } else | |
1215 | enable_trace_probe(tp, TP_FLAG_TRACE); | |
1216 | } | |
1217 | ||
1218 | ret = traceprobe_command("r:testprobe2 kprobe_trace_selftest_target " | |
1219 | "$retval", create_trace_probe); | |
1220 | if (WARN_ON_ONCE(ret)) { | |
1221 | pr_warning("error on probing function return.\n"); | |
1222 | warn++; | |
1223 | } else { | |
1224 | /* Enable trace point */ | |
1225 | tp = find_trace_probe("testprobe2", KPROBE_EVENT_SYSTEM); | |
1226 | if (WARN_ON_ONCE(tp == NULL)) { | |
1227 | pr_warning("error on getting new probe.\n"); | |
1228 | warn++; | |
1229 | } else | |
1230 | enable_trace_probe(tp, TP_FLAG_TRACE); | |
1231 | } | |
1232 | ||
1233 | if (warn) | |
1234 | goto end; | |
1235 | ||
1236 | ret = target(1, 2, 3, 4, 5, 6); | |
1237 | ||
1238 | /* Disable trace points before removing it */ | |
1239 | tp = find_trace_probe("testprobe", KPROBE_EVENT_SYSTEM); | |
1240 | if (WARN_ON_ONCE(tp == NULL)) { | |
1241 | pr_warning("error on getting test probe.\n"); | |
1242 | warn++; | |
1243 | } else | |
1244 | disable_trace_probe(tp, TP_FLAG_TRACE); | |
1245 | ||
1246 | tp = find_trace_probe("testprobe2", KPROBE_EVENT_SYSTEM); | |
1247 | if (WARN_ON_ONCE(tp == NULL)) { | |
1248 | pr_warning("error on getting 2nd test probe.\n"); | |
1249 | warn++; | |
1250 | } else | |
1251 | disable_trace_probe(tp, TP_FLAG_TRACE); | |
1252 | ||
1253 | ret = traceprobe_command("-:testprobe", create_trace_probe); | |
1254 | if (WARN_ON_ONCE(ret)) { | |
1255 | pr_warning("error on deleting a probe.\n"); | |
1256 | warn++; | |
1257 | } | |
1258 | ||
1259 | ret = traceprobe_command("-:testprobe2", create_trace_probe); | |
1260 | if (WARN_ON_ONCE(ret)) { | |
1261 | pr_warning("error on deleting a probe.\n"); | |
1262 | warn++; | |
1263 | } | |
1264 | ||
1265 | end: | |
1266 | release_all_trace_probes(); | |
1267 | if (warn) | |
1268 | pr_cont("NG: Some tests are failed. Please check them.\n"); | |
1269 | else | |
1270 | pr_cont("OK\n"); | |
1271 | return 0; | |
1272 | } | |
1273 | ||
1274 | late_initcall(kprobe_trace_self_tests_init); | |
1275 | ||
1276 | #endif |