Commit | Line | Data |
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f3f096cf SD |
1 | /* |
2 | * uprobes-based tracing events | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License version 2 as | |
6 | * published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
11 | * GNU General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public License | |
14 | * along with this program; if not, write to the Free Software | |
15 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
16 | * | |
17 | * Copyright (C) IBM Corporation, 2010-2012 | |
18 | * Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com> | |
19 | */ | |
20 | ||
21 | #include <linux/module.h> | |
22 | #include <linux/uaccess.h> | |
23 | #include <linux/uprobes.h> | |
24 | #include <linux/namei.h> | |
b2e902f0 | 25 | #include <linux/string.h> |
f3f096cf SD |
26 | |
27 | #include "trace_probe.h" | |
28 | ||
29 | #define UPROBE_EVENT_SYSTEM "uprobes" | |
30 | ||
457d1772 ON |
31 | struct uprobe_trace_entry_head { |
32 | struct trace_entry ent; | |
33 | unsigned long vaddr[]; | |
34 | }; | |
35 | ||
36 | #define SIZEOF_TRACE_ENTRY(is_return) \ | |
37 | (sizeof(struct uprobe_trace_entry_head) + \ | |
38 | sizeof(unsigned long) * (is_return ? 2 : 1)) | |
39 | ||
40 | #define DATAOF_TRACE_ENTRY(entry, is_return) \ | |
41 | ((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return)) | |
42 | ||
736288ba ON |
43 | struct trace_uprobe_filter { |
44 | rwlock_t rwlock; | |
45 | int nr_systemwide; | |
46 | struct list_head perf_events; | |
47 | }; | |
48 | ||
f3f096cf SD |
49 | /* |
50 | * uprobe event core functions | |
51 | */ | |
f3f096cf SD |
52 | struct trace_uprobe { |
53 | struct list_head list; | |
54 | struct ftrace_event_class class; | |
55 | struct ftrace_event_call call; | |
736288ba | 56 | struct trace_uprobe_filter filter; |
a932b738 | 57 | struct uprobe_consumer consumer; |
f3f096cf SD |
58 | struct inode *inode; |
59 | char *filename; | |
60 | unsigned long offset; | |
61 | unsigned long nhit; | |
62 | unsigned int flags; /* For TP_FLAG_* */ | |
63 | ssize_t size; /* trace entry size */ | |
64 | unsigned int nr_args; | |
65 | struct probe_arg args[]; | |
66 | }; | |
67 | ||
68 | #define SIZEOF_TRACE_UPROBE(n) \ | |
69 | (offsetof(struct trace_uprobe, args) + \ | |
70 | (sizeof(struct probe_arg) * (n))) | |
71 | ||
72 | static int register_uprobe_event(struct trace_uprobe *tu); | |
c6c2401d | 73 | static int unregister_uprobe_event(struct trace_uprobe *tu); |
f3f096cf SD |
74 | |
75 | static DEFINE_MUTEX(uprobe_lock); | |
76 | static LIST_HEAD(uprobe_list); | |
77 | ||
78 | static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs); | |
c1ae5c75 ON |
79 | static int uretprobe_dispatcher(struct uprobe_consumer *con, |
80 | unsigned long func, struct pt_regs *regs); | |
f3f096cf | 81 | |
736288ba ON |
82 | static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter) |
83 | { | |
84 | rwlock_init(&filter->rwlock); | |
85 | filter->nr_systemwide = 0; | |
86 | INIT_LIST_HEAD(&filter->perf_events); | |
87 | } | |
88 | ||
89 | static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter) | |
90 | { | |
91 | return !filter->nr_systemwide && list_empty(&filter->perf_events); | |
92 | } | |
93 | ||
c1ae5c75 ON |
94 | static inline bool is_ret_probe(struct trace_uprobe *tu) |
95 | { | |
96 | return tu->consumer.ret_handler != NULL; | |
97 | } | |
98 | ||
f3f096cf SD |
99 | /* |
100 | * Allocate new trace_uprobe and initialize it (including uprobes). | |
101 | */ | |
102 | static struct trace_uprobe * | |
c1ae5c75 | 103 | alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret) |
f3f096cf SD |
104 | { |
105 | struct trace_uprobe *tu; | |
106 | ||
107 | if (!event || !is_good_name(event)) | |
108 | return ERR_PTR(-EINVAL); | |
109 | ||
110 | if (!group || !is_good_name(group)) | |
111 | return ERR_PTR(-EINVAL); | |
112 | ||
113 | tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL); | |
114 | if (!tu) | |
115 | return ERR_PTR(-ENOMEM); | |
116 | ||
117 | tu->call.class = &tu->class; | |
118 | tu->call.name = kstrdup(event, GFP_KERNEL); | |
119 | if (!tu->call.name) | |
120 | goto error; | |
121 | ||
122 | tu->class.system = kstrdup(group, GFP_KERNEL); | |
123 | if (!tu->class.system) | |
124 | goto error; | |
125 | ||
126 | INIT_LIST_HEAD(&tu->list); | |
a932b738 | 127 | tu->consumer.handler = uprobe_dispatcher; |
c1ae5c75 ON |
128 | if (is_ret) |
129 | tu->consumer.ret_handler = uretprobe_dispatcher; | |
736288ba | 130 | init_trace_uprobe_filter(&tu->filter); |
f3f096cf SD |
131 | return tu; |
132 | ||
133 | error: | |
134 | kfree(tu->call.name); | |
135 | kfree(tu); | |
136 | ||
137 | return ERR_PTR(-ENOMEM); | |
138 | } | |
139 | ||
140 | static void free_trace_uprobe(struct trace_uprobe *tu) | |
141 | { | |
142 | int i; | |
143 | ||
144 | for (i = 0; i < tu->nr_args; i++) | |
145 | traceprobe_free_probe_arg(&tu->args[i]); | |
146 | ||
147 | iput(tu->inode); | |
148 | kfree(tu->call.class->system); | |
149 | kfree(tu->call.name); | |
150 | kfree(tu->filename); | |
151 | kfree(tu); | |
152 | } | |
153 | ||
154 | static struct trace_uprobe *find_probe_event(const char *event, const char *group) | |
155 | { | |
156 | struct trace_uprobe *tu; | |
157 | ||
158 | list_for_each_entry(tu, &uprobe_list, list) | |
159 | if (strcmp(tu->call.name, event) == 0 && | |
160 | strcmp(tu->call.class->system, group) == 0) | |
161 | return tu; | |
162 | ||
163 | return NULL; | |
164 | } | |
165 | ||
166 | /* Unregister a trace_uprobe and probe_event: call with locking uprobe_lock */ | |
c6c2401d | 167 | static int unregister_trace_uprobe(struct trace_uprobe *tu) |
f3f096cf | 168 | { |
c6c2401d SRRH |
169 | int ret; |
170 | ||
171 | ret = unregister_uprobe_event(tu); | |
172 | if (ret) | |
173 | return ret; | |
174 | ||
f3f096cf | 175 | list_del(&tu->list); |
f3f096cf | 176 | free_trace_uprobe(tu); |
c6c2401d | 177 | return 0; |
f3f096cf SD |
178 | } |
179 | ||
180 | /* Register a trace_uprobe and probe_event */ | |
181 | static int register_trace_uprobe(struct trace_uprobe *tu) | |
182 | { | |
183 | struct trace_uprobe *old_tp; | |
184 | int ret; | |
185 | ||
186 | mutex_lock(&uprobe_lock); | |
187 | ||
188 | /* register as an event */ | |
189 | old_tp = find_probe_event(tu->call.name, tu->call.class->system); | |
c6c2401d | 190 | if (old_tp) { |
f3f096cf | 191 | /* delete old event */ |
c6c2401d SRRH |
192 | ret = unregister_trace_uprobe(old_tp); |
193 | if (ret) | |
194 | goto end; | |
195 | } | |
f3f096cf SD |
196 | |
197 | ret = register_uprobe_event(tu); | |
198 | if (ret) { | |
199 | pr_warning("Failed to register probe event(%d)\n", ret); | |
200 | goto end; | |
201 | } | |
202 | ||
203 | list_add_tail(&tu->list, &uprobe_list); | |
204 | ||
205 | end: | |
206 | mutex_unlock(&uprobe_lock); | |
207 | ||
208 | return ret; | |
209 | } | |
210 | ||
211 | /* | |
212 | * Argument syntax: | |
4ee5a52e | 213 | * - Add uprobe: p|r[:[GRP/]EVENT] PATH:SYMBOL [FETCHARGS] |
f3f096cf SD |
214 | * |
215 | * - Remove uprobe: -:[GRP/]EVENT | |
216 | */ | |
217 | static int create_trace_uprobe(int argc, char **argv) | |
218 | { | |
219 | struct trace_uprobe *tu; | |
220 | struct inode *inode; | |
221 | char *arg, *event, *group, *filename; | |
222 | char buf[MAX_EVENT_NAME_LEN]; | |
223 | struct path path; | |
224 | unsigned long offset; | |
4ee5a52e | 225 | bool is_delete, is_return; |
f3f096cf SD |
226 | int i, ret; |
227 | ||
228 | inode = NULL; | |
229 | ret = 0; | |
230 | is_delete = false; | |
4ee5a52e | 231 | is_return = false; |
f3f096cf SD |
232 | event = NULL; |
233 | group = NULL; | |
234 | ||
235 | /* argc must be >= 1 */ | |
236 | if (argv[0][0] == '-') | |
237 | is_delete = true; | |
4ee5a52e ON |
238 | else if (argv[0][0] == 'r') |
239 | is_return = true; | |
f3f096cf | 240 | else if (argv[0][0] != 'p') { |
4ee5a52e | 241 | pr_info("Probe definition must be started with 'p', 'r' or '-'.\n"); |
f3f096cf SD |
242 | return -EINVAL; |
243 | } | |
244 | ||
245 | if (argv[0][1] == ':') { | |
246 | event = &argv[0][2]; | |
247 | arg = strchr(event, '/'); | |
248 | ||
249 | if (arg) { | |
250 | group = event; | |
251 | event = arg + 1; | |
252 | event[-1] = '\0'; | |
253 | ||
254 | if (strlen(group) == 0) { | |
255 | pr_info("Group name is not specified\n"); | |
256 | return -EINVAL; | |
257 | } | |
258 | } | |
259 | if (strlen(event) == 0) { | |
260 | pr_info("Event name is not specified\n"); | |
261 | return -EINVAL; | |
262 | } | |
263 | } | |
264 | if (!group) | |
265 | group = UPROBE_EVENT_SYSTEM; | |
266 | ||
267 | if (is_delete) { | |
c6c2401d SRRH |
268 | int ret; |
269 | ||
f3f096cf SD |
270 | if (!event) { |
271 | pr_info("Delete command needs an event name.\n"); | |
272 | return -EINVAL; | |
273 | } | |
274 | mutex_lock(&uprobe_lock); | |
275 | tu = find_probe_event(event, group); | |
276 | ||
277 | if (!tu) { | |
278 | mutex_unlock(&uprobe_lock); | |
279 | pr_info("Event %s/%s doesn't exist.\n", group, event); | |
280 | return -ENOENT; | |
281 | } | |
282 | /* delete an event */ | |
c6c2401d | 283 | ret = unregister_trace_uprobe(tu); |
f3f096cf | 284 | mutex_unlock(&uprobe_lock); |
c6c2401d | 285 | return ret; |
f3f096cf SD |
286 | } |
287 | ||
288 | if (argc < 2) { | |
289 | pr_info("Probe point is not specified.\n"); | |
290 | return -EINVAL; | |
291 | } | |
292 | if (isdigit(argv[1][0])) { | |
293 | pr_info("probe point must be have a filename.\n"); | |
294 | return -EINVAL; | |
295 | } | |
296 | arg = strchr(argv[1], ':'); | |
fa44063f J |
297 | if (!arg) { |
298 | ret = -EINVAL; | |
f3f096cf | 299 | goto fail_address_parse; |
fa44063f | 300 | } |
f3f096cf SD |
301 | |
302 | *arg++ = '\0'; | |
303 | filename = argv[1]; | |
304 | ret = kern_path(filename, LOOKUP_FOLLOW, &path); | |
305 | if (ret) | |
306 | goto fail_address_parse; | |
307 | ||
f3f096cf | 308 | inode = igrab(path.dentry->d_inode); |
84d7ed79 ON |
309 | path_put(&path); |
310 | ||
7e4e28c5 | 311 | if (!inode || !S_ISREG(inode->i_mode)) { |
d24d7dbf JZ |
312 | ret = -EINVAL; |
313 | goto fail_address_parse; | |
314 | } | |
f3f096cf | 315 | |
84d7ed79 ON |
316 | ret = kstrtoul(arg, 0, &offset); |
317 | if (ret) | |
318 | goto fail_address_parse; | |
319 | ||
f3f096cf SD |
320 | argc -= 2; |
321 | argv += 2; | |
322 | ||
323 | /* setup a probe */ | |
324 | if (!event) { | |
b2e902f0 | 325 | char *tail; |
f3f096cf SD |
326 | char *ptr; |
327 | ||
b2e902f0 AS |
328 | tail = kstrdup(kbasename(filename), GFP_KERNEL); |
329 | if (!tail) { | |
f3f096cf SD |
330 | ret = -ENOMEM; |
331 | goto fail_address_parse; | |
332 | } | |
333 | ||
f3f096cf SD |
334 | ptr = strpbrk(tail, ".-_"); |
335 | if (ptr) | |
336 | *ptr = '\0'; | |
337 | ||
338 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset); | |
339 | event = buf; | |
340 | kfree(tail); | |
341 | } | |
342 | ||
4ee5a52e | 343 | tu = alloc_trace_uprobe(group, event, argc, is_return); |
f3f096cf SD |
344 | if (IS_ERR(tu)) { |
345 | pr_info("Failed to allocate trace_uprobe.(%d)\n", (int)PTR_ERR(tu)); | |
346 | ret = PTR_ERR(tu); | |
347 | goto fail_address_parse; | |
348 | } | |
349 | tu->offset = offset; | |
350 | tu->inode = inode; | |
351 | tu->filename = kstrdup(filename, GFP_KERNEL); | |
352 | ||
353 | if (!tu->filename) { | |
354 | pr_info("Failed to allocate filename.\n"); | |
355 | ret = -ENOMEM; | |
356 | goto error; | |
357 | } | |
358 | ||
359 | /* parse arguments */ | |
360 | ret = 0; | |
361 | for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { | |
362 | /* Increment count for freeing args in error case */ | |
363 | tu->nr_args++; | |
364 | ||
365 | /* Parse argument name */ | |
366 | arg = strchr(argv[i], '='); | |
367 | if (arg) { | |
368 | *arg++ = '\0'; | |
369 | tu->args[i].name = kstrdup(argv[i], GFP_KERNEL); | |
370 | } else { | |
371 | arg = argv[i]; | |
372 | /* If argument name is omitted, set "argN" */ | |
373 | snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1); | |
374 | tu->args[i].name = kstrdup(buf, GFP_KERNEL); | |
375 | } | |
376 | ||
377 | if (!tu->args[i].name) { | |
378 | pr_info("Failed to allocate argument[%d] name.\n", i); | |
379 | ret = -ENOMEM; | |
380 | goto error; | |
381 | } | |
382 | ||
383 | if (!is_good_name(tu->args[i].name)) { | |
384 | pr_info("Invalid argument[%d] name: %s\n", i, tu->args[i].name); | |
385 | ret = -EINVAL; | |
386 | goto error; | |
387 | } | |
388 | ||
389 | if (traceprobe_conflict_field_name(tu->args[i].name, tu->args, i)) { | |
390 | pr_info("Argument[%d] name '%s' conflicts with " | |
391 | "another field.\n", i, argv[i]); | |
392 | ret = -EINVAL; | |
393 | goto error; | |
394 | } | |
395 | ||
396 | /* Parse fetch argument */ | |
397 | ret = traceprobe_parse_probe_arg(arg, &tu->size, &tu->args[i], false, false); | |
398 | if (ret) { | |
399 | pr_info("Parse error at argument[%d]. (%d)\n", i, ret); | |
400 | goto error; | |
401 | } | |
402 | } | |
403 | ||
404 | ret = register_trace_uprobe(tu); | |
405 | if (ret) | |
406 | goto error; | |
407 | return 0; | |
408 | ||
409 | error: | |
410 | free_trace_uprobe(tu); | |
411 | return ret; | |
412 | ||
413 | fail_address_parse: | |
414 | if (inode) | |
415 | iput(inode); | |
416 | ||
d24d7dbf | 417 | pr_info("Failed to parse address or file.\n"); |
f3f096cf SD |
418 | |
419 | return ret; | |
420 | } | |
421 | ||
c6c2401d | 422 | static int cleanup_all_probes(void) |
f3f096cf SD |
423 | { |
424 | struct trace_uprobe *tu; | |
c6c2401d | 425 | int ret = 0; |
f3f096cf SD |
426 | |
427 | mutex_lock(&uprobe_lock); | |
428 | while (!list_empty(&uprobe_list)) { | |
429 | tu = list_entry(uprobe_list.next, struct trace_uprobe, list); | |
c6c2401d SRRH |
430 | ret = unregister_trace_uprobe(tu); |
431 | if (ret) | |
432 | break; | |
f3f096cf SD |
433 | } |
434 | mutex_unlock(&uprobe_lock); | |
c6c2401d | 435 | return ret; |
f3f096cf SD |
436 | } |
437 | ||
438 | /* Probes listing interfaces */ | |
439 | static void *probes_seq_start(struct seq_file *m, loff_t *pos) | |
440 | { | |
441 | mutex_lock(&uprobe_lock); | |
442 | return seq_list_start(&uprobe_list, *pos); | |
443 | } | |
444 | ||
445 | static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos) | |
446 | { | |
447 | return seq_list_next(v, &uprobe_list, pos); | |
448 | } | |
449 | ||
450 | static void probes_seq_stop(struct seq_file *m, void *v) | |
451 | { | |
452 | mutex_unlock(&uprobe_lock); | |
453 | } | |
454 | ||
455 | static int probes_seq_show(struct seq_file *m, void *v) | |
456 | { | |
457 | struct trace_uprobe *tu = v; | |
3ede82dd | 458 | char c = is_ret_probe(tu) ? 'r' : 'p'; |
f3f096cf SD |
459 | int i; |
460 | ||
3ede82dd | 461 | seq_printf(m, "%c:%s/%s", c, tu->call.class->system, tu->call.name); |
f3f096cf SD |
462 | seq_printf(m, " %s:0x%p", tu->filename, (void *)tu->offset); |
463 | ||
464 | for (i = 0; i < tu->nr_args; i++) | |
465 | seq_printf(m, " %s=%s", tu->args[i].name, tu->args[i].comm); | |
466 | ||
467 | seq_printf(m, "\n"); | |
468 | return 0; | |
469 | } | |
470 | ||
471 | static const struct seq_operations probes_seq_op = { | |
472 | .start = probes_seq_start, | |
473 | .next = probes_seq_next, | |
474 | .stop = probes_seq_stop, | |
475 | .show = probes_seq_show | |
476 | }; | |
477 | ||
478 | static int probes_open(struct inode *inode, struct file *file) | |
479 | { | |
c6c2401d SRRH |
480 | int ret; |
481 | ||
482 | if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { | |
483 | ret = cleanup_all_probes(); | |
484 | if (ret) | |
485 | return ret; | |
486 | } | |
f3f096cf SD |
487 | |
488 | return seq_open(file, &probes_seq_op); | |
489 | } | |
490 | ||
491 | static ssize_t probes_write(struct file *file, const char __user *buffer, | |
492 | size_t count, loff_t *ppos) | |
493 | { | |
494 | return traceprobe_probes_write(file, buffer, count, ppos, create_trace_uprobe); | |
495 | } | |
496 | ||
497 | static const struct file_operations uprobe_events_ops = { | |
498 | .owner = THIS_MODULE, | |
499 | .open = probes_open, | |
500 | .read = seq_read, | |
501 | .llseek = seq_lseek, | |
502 | .release = seq_release, | |
503 | .write = probes_write, | |
504 | }; | |
505 | ||
506 | /* Probes profiling interfaces */ | |
507 | static int probes_profile_seq_show(struct seq_file *m, void *v) | |
508 | { | |
509 | struct trace_uprobe *tu = v; | |
510 | ||
511 | seq_printf(m, " %s %-44s %15lu\n", tu->filename, tu->call.name, tu->nhit); | |
512 | return 0; | |
513 | } | |
514 | ||
515 | static const struct seq_operations profile_seq_op = { | |
516 | .start = probes_seq_start, | |
517 | .next = probes_seq_next, | |
518 | .stop = probes_seq_stop, | |
519 | .show = probes_profile_seq_show | |
520 | }; | |
521 | ||
522 | static int profile_open(struct inode *inode, struct file *file) | |
523 | { | |
524 | return seq_open(file, &profile_seq_op); | |
525 | } | |
526 | ||
527 | static const struct file_operations uprobe_profile_ops = { | |
528 | .owner = THIS_MODULE, | |
529 | .open = profile_open, | |
530 | .read = seq_read, | |
531 | .llseek = seq_lseek, | |
532 | .release = seq_release, | |
533 | }; | |
534 | ||
a51cc604 ON |
535 | static void uprobe_trace_print(struct trace_uprobe *tu, |
536 | unsigned long func, struct pt_regs *regs) | |
f3f096cf SD |
537 | { |
538 | struct uprobe_trace_entry_head *entry; | |
539 | struct ring_buffer_event *event; | |
540 | struct ring_buffer *buffer; | |
457d1772 | 541 | void *data; |
0e3853d2 | 542 | int size, i; |
f3f096cf SD |
543 | struct ftrace_event_call *call = &tu->call; |
544 | ||
393a736c | 545 | size = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); |
f3f096cf | 546 | event = trace_current_buffer_lock_reserve(&buffer, call->event.type, |
393a736c | 547 | size + tu->size, 0, 0); |
f3f096cf | 548 | if (!event) |
a51cc604 | 549 | return; |
f3f096cf SD |
550 | |
551 | entry = ring_buffer_event_data(event); | |
393a736c ON |
552 | if (is_ret_probe(tu)) { |
553 | entry->vaddr[0] = func; | |
554 | entry->vaddr[1] = instruction_pointer(regs); | |
555 | data = DATAOF_TRACE_ENTRY(entry, true); | |
556 | } else { | |
557 | entry->vaddr[0] = instruction_pointer(regs); | |
558 | data = DATAOF_TRACE_ENTRY(entry, false); | |
559 | } | |
560 | ||
f3f096cf SD |
561 | for (i = 0; i < tu->nr_args; i++) |
562 | call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset); | |
563 | ||
564 | if (!filter_current_check_discard(buffer, call, entry, event)) | |
0e3853d2 | 565 | trace_buffer_unlock_commit(buffer, event, 0, 0); |
a51cc604 | 566 | } |
f42d24a1 | 567 | |
a51cc604 ON |
568 | /* uprobe handler */ |
569 | static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs) | |
570 | { | |
393a736c ON |
571 | if (!is_ret_probe(tu)) |
572 | uprobe_trace_print(tu, 0, regs); | |
f42d24a1 | 573 | return 0; |
f3f096cf SD |
574 | } |
575 | ||
c1ae5c75 ON |
576 | static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func, |
577 | struct pt_regs *regs) | |
578 | { | |
579 | uprobe_trace_print(tu, func, regs); | |
580 | } | |
581 | ||
f3f096cf SD |
582 | /* Event entry printers */ |
583 | static enum print_line_t | |
584 | print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event) | |
585 | { | |
457d1772 | 586 | struct uprobe_trace_entry_head *entry; |
f3f096cf SD |
587 | struct trace_seq *s = &iter->seq; |
588 | struct trace_uprobe *tu; | |
589 | u8 *data; | |
590 | int i; | |
591 | ||
457d1772 | 592 | entry = (struct uprobe_trace_entry_head *)iter->ent; |
f3f096cf SD |
593 | tu = container_of(event, struct trace_uprobe, call.event); |
594 | ||
3ede82dd ON |
595 | if (is_ret_probe(tu)) { |
596 | if (!trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)", tu->call.name, | |
597 | entry->vaddr[1], entry->vaddr[0])) | |
598 | goto partial; | |
599 | data = DATAOF_TRACE_ENTRY(entry, true); | |
600 | } else { | |
601 | if (!trace_seq_printf(s, "%s: (0x%lx)", tu->call.name, | |
602 | entry->vaddr[0])) | |
603 | goto partial; | |
604 | data = DATAOF_TRACE_ENTRY(entry, false); | |
605 | } | |
f3f096cf | 606 | |
f3f096cf SD |
607 | for (i = 0; i < tu->nr_args; i++) { |
608 | if (!tu->args[i].type->print(s, tu->args[i].name, | |
457d1772 | 609 | data + tu->args[i].offset, entry)) |
f3f096cf SD |
610 | goto partial; |
611 | } | |
612 | ||
613 | if (trace_seq_puts(s, "\n")) | |
614 | return TRACE_TYPE_HANDLED; | |
615 | ||
616 | partial: | |
617 | return TRACE_TYPE_PARTIAL_LINE; | |
618 | } | |
619 | ||
b64b0077 ON |
620 | static inline bool is_trace_uprobe_enabled(struct trace_uprobe *tu) |
621 | { | |
622 | return tu->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE); | |
623 | } | |
624 | ||
31ba3348 ON |
625 | typedef bool (*filter_func_t)(struct uprobe_consumer *self, |
626 | enum uprobe_filter_ctx ctx, | |
627 | struct mm_struct *mm); | |
628 | ||
629 | static int | |
630 | probe_event_enable(struct trace_uprobe *tu, int flag, filter_func_t filter) | |
f3f096cf | 631 | { |
f3f096cf SD |
632 | int ret = 0; |
633 | ||
b64b0077 | 634 | if (is_trace_uprobe_enabled(tu)) |
f3f096cf SD |
635 | return -EINTR; |
636 | ||
736288ba ON |
637 | WARN_ON(!uprobe_filter_is_empty(&tu->filter)); |
638 | ||
4161824f | 639 | tu->flags |= flag; |
31ba3348 | 640 | tu->consumer.filter = filter; |
a932b738 ON |
641 | ret = uprobe_register(tu->inode, tu->offset, &tu->consumer); |
642 | if (ret) | |
4161824f | 643 | tu->flags &= ~flag; |
f3f096cf | 644 | |
4161824f | 645 | return ret; |
f3f096cf SD |
646 | } |
647 | ||
648 | static void probe_event_disable(struct trace_uprobe *tu, int flag) | |
649 | { | |
b64b0077 | 650 | if (!is_trace_uprobe_enabled(tu)) |
f3f096cf SD |
651 | return; |
652 | ||
736288ba ON |
653 | WARN_ON(!uprobe_filter_is_empty(&tu->filter)); |
654 | ||
a932b738 | 655 | uprobe_unregister(tu->inode, tu->offset, &tu->consumer); |
f3f096cf | 656 | tu->flags &= ~flag; |
f3f096cf SD |
657 | } |
658 | ||
659 | static int uprobe_event_define_fields(struct ftrace_event_call *event_call) | |
660 | { | |
457d1772 | 661 | int ret, i, size; |
f3f096cf | 662 | struct uprobe_trace_entry_head field; |
457d1772 | 663 | struct trace_uprobe *tu = event_call->data; |
f3f096cf | 664 | |
4d1298e2 ON |
665 | if (is_ret_probe(tu)) { |
666 | DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0); | |
667 | DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0); | |
668 | size = SIZEOF_TRACE_ENTRY(true); | |
669 | } else { | |
670 | DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0); | |
671 | size = SIZEOF_TRACE_ENTRY(false); | |
672 | } | |
f3f096cf SD |
673 | /* Set argument names as fields */ |
674 | for (i = 0; i < tu->nr_args; i++) { | |
675 | ret = trace_define_field(event_call, tu->args[i].type->fmttype, | |
676 | tu->args[i].name, | |
457d1772 | 677 | size + tu->args[i].offset, |
f3f096cf SD |
678 | tu->args[i].type->size, |
679 | tu->args[i].type->is_signed, | |
680 | FILTER_OTHER); | |
681 | ||
682 | if (ret) | |
683 | return ret; | |
684 | } | |
685 | return 0; | |
686 | } | |
687 | ||
688 | #define LEN_OR_ZERO (len ? len - pos : 0) | |
689 | static int __set_print_fmt(struct trace_uprobe *tu, char *buf, int len) | |
690 | { | |
691 | const char *fmt, *arg; | |
692 | int i; | |
693 | int pos = 0; | |
694 | ||
4d1298e2 ON |
695 | if (is_ret_probe(tu)) { |
696 | fmt = "(%lx <- %lx)"; | |
697 | arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP; | |
698 | } else { | |
699 | fmt = "(%lx)"; | |
700 | arg = "REC->" FIELD_STRING_IP; | |
701 | } | |
f3f096cf SD |
702 | |
703 | /* When len=0, we just calculate the needed length */ | |
704 | ||
705 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt); | |
706 | ||
707 | for (i = 0; i < tu->nr_args; i++) { | |
708 | pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s", | |
709 | tu->args[i].name, tu->args[i].type->fmt); | |
710 | } | |
711 | ||
712 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg); | |
713 | ||
714 | for (i = 0; i < tu->nr_args; i++) { | |
715 | pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s", | |
716 | tu->args[i].name); | |
717 | } | |
718 | ||
719 | return pos; /* return the length of print_fmt */ | |
720 | } | |
721 | #undef LEN_OR_ZERO | |
722 | ||
723 | static int set_print_fmt(struct trace_uprobe *tu) | |
724 | { | |
725 | char *print_fmt; | |
726 | int len; | |
727 | ||
728 | /* First: called with 0 length to calculate the needed length */ | |
729 | len = __set_print_fmt(tu, NULL, 0); | |
730 | print_fmt = kmalloc(len + 1, GFP_KERNEL); | |
731 | if (!print_fmt) | |
732 | return -ENOMEM; | |
733 | ||
734 | /* Second: actually write the @print_fmt */ | |
735 | __set_print_fmt(tu, print_fmt, len + 1); | |
736 | tu->call.print_fmt = print_fmt; | |
737 | ||
738 | return 0; | |
739 | } | |
740 | ||
741 | #ifdef CONFIG_PERF_EVENTS | |
31ba3348 ON |
742 | static bool |
743 | __uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm) | |
744 | { | |
745 | struct perf_event *event; | |
746 | ||
747 | if (filter->nr_systemwide) | |
748 | return true; | |
749 | ||
750 | list_for_each_entry(event, &filter->perf_events, hw.tp_list) { | |
751 | if (event->hw.tp_target->mm == mm) | |
752 | return true; | |
753 | } | |
754 | ||
755 | return false; | |
756 | } | |
757 | ||
b2fe8ba6 ON |
758 | static inline bool |
759 | uprobe_filter_event(struct trace_uprobe *tu, struct perf_event *event) | |
760 | { | |
761 | return __uprobe_perf_filter(&tu->filter, event->hw.tp_target->mm); | |
762 | } | |
763 | ||
736288ba ON |
764 | static int uprobe_perf_open(struct trace_uprobe *tu, struct perf_event *event) |
765 | { | |
b2fe8ba6 ON |
766 | bool done; |
767 | ||
736288ba | 768 | write_lock(&tu->filter.rwlock); |
b2fe8ba6 ON |
769 | if (event->hw.tp_target) { |
770 | /* | |
771 | * event->parent != NULL means copy_process(), we can avoid | |
772 | * uprobe_apply(). current->mm must be probed and we can rely | |
773 | * on dup_mmap() which preserves the already installed bp's. | |
774 | * | |
775 | * attr.enable_on_exec means that exec/mmap will install the | |
776 | * breakpoints we need. | |
777 | */ | |
778 | done = tu->filter.nr_systemwide || | |
779 | event->parent || event->attr.enable_on_exec || | |
780 | uprobe_filter_event(tu, event); | |
736288ba | 781 | list_add(&event->hw.tp_list, &tu->filter.perf_events); |
b2fe8ba6 ON |
782 | } else { |
783 | done = tu->filter.nr_systemwide; | |
736288ba | 784 | tu->filter.nr_systemwide++; |
b2fe8ba6 | 785 | } |
736288ba ON |
786 | write_unlock(&tu->filter.rwlock); |
787 | ||
b2fe8ba6 ON |
788 | if (!done) |
789 | uprobe_apply(tu->inode, tu->offset, &tu->consumer, true); | |
31ba3348 | 790 | |
736288ba ON |
791 | return 0; |
792 | } | |
793 | ||
794 | static int uprobe_perf_close(struct trace_uprobe *tu, struct perf_event *event) | |
795 | { | |
b2fe8ba6 ON |
796 | bool done; |
797 | ||
736288ba | 798 | write_lock(&tu->filter.rwlock); |
b2fe8ba6 | 799 | if (event->hw.tp_target) { |
736288ba | 800 | list_del(&event->hw.tp_list); |
b2fe8ba6 ON |
801 | done = tu->filter.nr_systemwide || |
802 | (event->hw.tp_target->flags & PF_EXITING) || | |
803 | uprobe_filter_event(tu, event); | |
804 | } else { | |
736288ba | 805 | tu->filter.nr_systemwide--; |
b2fe8ba6 ON |
806 | done = tu->filter.nr_systemwide; |
807 | } | |
736288ba ON |
808 | write_unlock(&tu->filter.rwlock); |
809 | ||
b2fe8ba6 ON |
810 | if (!done) |
811 | uprobe_apply(tu->inode, tu->offset, &tu->consumer, false); | |
31ba3348 | 812 | |
736288ba ON |
813 | return 0; |
814 | } | |
815 | ||
31ba3348 ON |
816 | static bool uprobe_perf_filter(struct uprobe_consumer *uc, |
817 | enum uprobe_filter_ctx ctx, struct mm_struct *mm) | |
818 | { | |
819 | struct trace_uprobe *tu; | |
820 | int ret; | |
821 | ||
822 | tu = container_of(uc, struct trace_uprobe, consumer); | |
823 | read_lock(&tu->filter.rwlock); | |
824 | ret = __uprobe_perf_filter(&tu->filter, mm); | |
825 | read_unlock(&tu->filter.rwlock); | |
826 | ||
827 | return ret; | |
828 | } | |
829 | ||
a51cc604 ON |
830 | static void uprobe_perf_print(struct trace_uprobe *tu, |
831 | unsigned long func, struct pt_regs *regs) | |
f3f096cf SD |
832 | { |
833 | struct ftrace_event_call *call = &tu->call; | |
834 | struct uprobe_trace_entry_head *entry; | |
835 | struct hlist_head *head; | |
457d1772 ON |
836 | void *data; |
837 | int size, rctx, i; | |
f3f096cf | 838 | |
393a736c | 839 | size = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); |
457d1772 | 840 | size = ALIGN(size + tu->size + sizeof(u32), sizeof(u64)) - sizeof(u32); |
f3f096cf SD |
841 | |
842 | preempt_disable(); | |
515619f2 ON |
843 | head = this_cpu_ptr(call->perf_events); |
844 | if (hlist_empty(head)) | |
845 | goto out; | |
846 | ||
f3f096cf SD |
847 | entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx); |
848 | if (!entry) | |
849 | goto out; | |
850 | ||
393a736c ON |
851 | if (is_ret_probe(tu)) { |
852 | entry->vaddr[0] = func; | |
32520b2c | 853 | entry->vaddr[1] = instruction_pointer(regs); |
393a736c ON |
854 | data = DATAOF_TRACE_ENTRY(entry, true); |
855 | } else { | |
32520b2c | 856 | entry->vaddr[0] = instruction_pointer(regs); |
393a736c ON |
857 | data = DATAOF_TRACE_ENTRY(entry, false); |
858 | } | |
859 | ||
f3f096cf SD |
860 | for (i = 0; i < tu->nr_args; i++) |
861 | call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset); | |
862 | ||
32520b2c | 863 | perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL); |
f3f096cf SD |
864 | out: |
865 | preempt_enable(); | |
a51cc604 ON |
866 | } |
867 | ||
868 | /* uprobe profile handler */ | |
869 | static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs) | |
870 | { | |
871 | if (!uprobe_perf_filter(&tu->consumer, 0, current->mm)) | |
872 | return UPROBE_HANDLER_REMOVE; | |
873 | ||
393a736c ON |
874 | if (!is_ret_probe(tu)) |
875 | uprobe_perf_print(tu, 0, regs); | |
f42d24a1 | 876 | return 0; |
f3f096cf | 877 | } |
c1ae5c75 ON |
878 | |
879 | static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func, | |
880 | struct pt_regs *regs) | |
881 | { | |
882 | uprobe_perf_print(tu, func, regs); | |
883 | } | |
f3f096cf SD |
884 | #endif /* CONFIG_PERF_EVENTS */ |
885 | ||
886 | static | |
887 | int trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type, void *data) | |
888 | { | |
457d1772 | 889 | struct trace_uprobe *tu = event->data; |
f3f096cf SD |
890 | |
891 | switch (type) { | |
892 | case TRACE_REG_REGISTER: | |
31ba3348 | 893 | return probe_event_enable(tu, TP_FLAG_TRACE, NULL); |
f3f096cf SD |
894 | |
895 | case TRACE_REG_UNREGISTER: | |
896 | probe_event_disable(tu, TP_FLAG_TRACE); | |
897 | return 0; | |
898 | ||
899 | #ifdef CONFIG_PERF_EVENTS | |
900 | case TRACE_REG_PERF_REGISTER: | |
31ba3348 | 901 | return probe_event_enable(tu, TP_FLAG_PROFILE, uprobe_perf_filter); |
f3f096cf SD |
902 | |
903 | case TRACE_REG_PERF_UNREGISTER: | |
904 | probe_event_disable(tu, TP_FLAG_PROFILE); | |
905 | return 0; | |
736288ba ON |
906 | |
907 | case TRACE_REG_PERF_OPEN: | |
908 | return uprobe_perf_open(tu, data); | |
909 | ||
910 | case TRACE_REG_PERF_CLOSE: | |
911 | return uprobe_perf_close(tu, data); | |
912 | ||
f3f096cf SD |
913 | #endif |
914 | default: | |
915 | return 0; | |
916 | } | |
917 | return 0; | |
918 | } | |
919 | ||
920 | static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs) | |
921 | { | |
f3f096cf | 922 | struct trace_uprobe *tu; |
f42d24a1 | 923 | int ret = 0; |
f3f096cf | 924 | |
a932b738 | 925 | tu = container_of(con, struct trace_uprobe, consumer); |
1b47aefd | 926 | tu->nhit++; |
f3f096cf SD |
927 | |
928 | if (tu->flags & TP_FLAG_TRACE) | |
f42d24a1 | 929 | ret |= uprobe_trace_func(tu, regs); |
f3f096cf SD |
930 | |
931 | #ifdef CONFIG_PERF_EVENTS | |
932 | if (tu->flags & TP_FLAG_PROFILE) | |
f42d24a1 | 933 | ret |= uprobe_perf_func(tu, regs); |
f3f096cf | 934 | #endif |
f42d24a1 | 935 | return ret; |
f3f096cf SD |
936 | } |
937 | ||
c1ae5c75 ON |
938 | static int uretprobe_dispatcher(struct uprobe_consumer *con, |
939 | unsigned long func, struct pt_regs *regs) | |
940 | { | |
941 | struct trace_uprobe *tu; | |
942 | ||
943 | tu = container_of(con, struct trace_uprobe, consumer); | |
944 | ||
945 | if (tu->flags & TP_FLAG_TRACE) | |
946 | uretprobe_trace_func(tu, func, regs); | |
947 | ||
948 | #ifdef CONFIG_PERF_EVENTS | |
949 | if (tu->flags & TP_FLAG_PROFILE) | |
950 | uretprobe_perf_func(tu, func, regs); | |
951 | #endif | |
952 | return 0; | |
953 | } | |
954 | ||
f3f096cf SD |
955 | static struct trace_event_functions uprobe_funcs = { |
956 | .trace = print_uprobe_event | |
957 | }; | |
958 | ||
959 | static int register_uprobe_event(struct trace_uprobe *tu) | |
960 | { | |
961 | struct ftrace_event_call *call = &tu->call; | |
962 | int ret; | |
963 | ||
964 | /* Initialize ftrace_event_call */ | |
965 | INIT_LIST_HEAD(&call->class->fields); | |
966 | call->event.funcs = &uprobe_funcs; | |
967 | call->class->define_fields = uprobe_event_define_fields; | |
968 | ||
969 | if (set_print_fmt(tu) < 0) | |
970 | return -ENOMEM; | |
971 | ||
972 | ret = register_ftrace_event(&call->event); | |
973 | if (!ret) { | |
974 | kfree(call->print_fmt); | |
975 | return -ENODEV; | |
976 | } | |
977 | call->flags = 0; | |
978 | call->class->reg = trace_uprobe_register; | |
979 | call->data = tu; | |
980 | ret = trace_add_event_call(call); | |
981 | ||
982 | if (ret) { | |
983 | pr_info("Failed to register uprobe event: %s\n", call->name); | |
984 | kfree(call->print_fmt); | |
985 | unregister_ftrace_event(&call->event); | |
986 | } | |
987 | ||
988 | return ret; | |
989 | } | |
990 | ||
c6c2401d | 991 | static int unregister_uprobe_event(struct trace_uprobe *tu) |
f3f096cf | 992 | { |
c6c2401d SRRH |
993 | int ret; |
994 | ||
f3f096cf | 995 | /* tu->event is unregistered in trace_remove_event_call() */ |
c6c2401d SRRH |
996 | ret = trace_remove_event_call(&tu->call); |
997 | if (ret) | |
998 | return ret; | |
f3f096cf SD |
999 | kfree(tu->call.print_fmt); |
1000 | tu->call.print_fmt = NULL; | |
c6c2401d | 1001 | return 0; |
f3f096cf SD |
1002 | } |
1003 | ||
1004 | /* Make a trace interface for controling probe points */ | |
1005 | static __init int init_uprobe_trace(void) | |
1006 | { | |
1007 | struct dentry *d_tracer; | |
1008 | ||
1009 | d_tracer = tracing_init_dentry(); | |
1010 | if (!d_tracer) | |
1011 | return 0; | |
1012 | ||
1013 | trace_create_file("uprobe_events", 0644, d_tracer, | |
1014 | NULL, &uprobe_events_ops); | |
1015 | /* Profile interface */ | |
1016 | trace_create_file("uprobe_profile", 0444, d_tracer, | |
1017 | NULL, &uprobe_profile_ops); | |
1018 | return 0; | |
1019 | } | |
1020 | ||
1021 | fs_initcall(init_uprobe_trace); |