Commit | Line | Data |
---|---|---|
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; | |
736288ba | 54 | struct trace_uprobe_filter filter; |
a932b738 | 55 | struct uprobe_consumer consumer; |
f3f096cf SD |
56 | struct inode *inode; |
57 | char *filename; | |
58 | unsigned long offset; | |
59 | unsigned long nhit; | |
14577c39 | 60 | struct trace_probe tp; |
f3f096cf SD |
61 | }; |
62 | ||
14577c39 NK |
63 | #define SIZEOF_TRACE_UPROBE(n) \ |
64 | (offsetof(struct trace_uprobe, tp.args) + \ | |
f3f096cf SD |
65 | (sizeof(struct probe_arg) * (n))) |
66 | ||
67 | static int register_uprobe_event(struct trace_uprobe *tu); | |
c6c2401d | 68 | static int unregister_uprobe_event(struct trace_uprobe *tu); |
f3f096cf SD |
69 | |
70 | static DEFINE_MUTEX(uprobe_lock); | |
71 | static LIST_HEAD(uprobe_list); | |
72 | ||
73 | static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs); | |
c1ae5c75 ON |
74 | static int uretprobe_dispatcher(struct uprobe_consumer *con, |
75 | unsigned long func, struct pt_regs *regs); | |
f3f096cf | 76 | |
736288ba ON |
77 | static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter) |
78 | { | |
79 | rwlock_init(&filter->rwlock); | |
80 | filter->nr_systemwide = 0; | |
81 | INIT_LIST_HEAD(&filter->perf_events); | |
82 | } | |
83 | ||
84 | static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter) | |
85 | { | |
86 | return !filter->nr_systemwide && list_empty(&filter->perf_events); | |
87 | } | |
88 | ||
c1ae5c75 ON |
89 | static inline bool is_ret_probe(struct trace_uprobe *tu) |
90 | { | |
91 | return tu->consumer.ret_handler != NULL; | |
92 | } | |
93 | ||
f3f096cf SD |
94 | /* |
95 | * Allocate new trace_uprobe and initialize it (including uprobes). | |
96 | */ | |
97 | static struct trace_uprobe * | |
c1ae5c75 | 98 | alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret) |
f3f096cf SD |
99 | { |
100 | struct trace_uprobe *tu; | |
101 | ||
102 | if (!event || !is_good_name(event)) | |
103 | return ERR_PTR(-EINVAL); | |
104 | ||
105 | if (!group || !is_good_name(group)) | |
106 | return ERR_PTR(-EINVAL); | |
107 | ||
108 | tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL); | |
109 | if (!tu) | |
110 | return ERR_PTR(-ENOMEM); | |
111 | ||
14577c39 NK |
112 | tu->tp.call.class = &tu->tp.class; |
113 | tu->tp.call.name = kstrdup(event, GFP_KERNEL); | |
114 | if (!tu->tp.call.name) | |
f3f096cf SD |
115 | goto error; |
116 | ||
14577c39 NK |
117 | tu->tp.class.system = kstrdup(group, GFP_KERNEL); |
118 | if (!tu->tp.class.system) | |
f3f096cf SD |
119 | goto error; |
120 | ||
121 | INIT_LIST_HEAD(&tu->list); | |
a932b738 | 122 | tu->consumer.handler = uprobe_dispatcher; |
c1ae5c75 ON |
123 | if (is_ret) |
124 | tu->consumer.ret_handler = uretprobe_dispatcher; | |
736288ba | 125 | init_trace_uprobe_filter(&tu->filter); |
14577c39 | 126 | tu->tp.call.flags |= TRACE_EVENT_FL_USE_CALL_FILTER; |
f3f096cf SD |
127 | return tu; |
128 | ||
129 | error: | |
14577c39 | 130 | kfree(tu->tp.call.name); |
f3f096cf SD |
131 | kfree(tu); |
132 | ||
133 | return ERR_PTR(-ENOMEM); | |
134 | } | |
135 | ||
136 | static void free_trace_uprobe(struct trace_uprobe *tu) | |
137 | { | |
138 | int i; | |
139 | ||
14577c39 NK |
140 | for (i = 0; i < tu->tp.nr_args; i++) |
141 | traceprobe_free_probe_arg(&tu->tp.args[i]); | |
f3f096cf SD |
142 | |
143 | iput(tu->inode); | |
14577c39 NK |
144 | kfree(tu->tp.call.class->system); |
145 | kfree(tu->tp.call.name); | |
f3f096cf SD |
146 | kfree(tu->filename); |
147 | kfree(tu); | |
148 | } | |
149 | ||
150 | static struct trace_uprobe *find_probe_event(const char *event, const char *group) | |
151 | { | |
152 | struct trace_uprobe *tu; | |
153 | ||
154 | list_for_each_entry(tu, &uprobe_list, list) | |
14577c39 NK |
155 | if (strcmp(tu->tp.call.name, event) == 0 && |
156 | strcmp(tu->tp.call.class->system, group) == 0) | |
f3f096cf SD |
157 | return tu; |
158 | ||
159 | return NULL; | |
160 | } | |
161 | ||
162 | /* Unregister a trace_uprobe and probe_event: call with locking uprobe_lock */ | |
c6c2401d | 163 | static int unregister_trace_uprobe(struct trace_uprobe *tu) |
f3f096cf | 164 | { |
c6c2401d SRRH |
165 | int ret; |
166 | ||
167 | ret = unregister_uprobe_event(tu); | |
168 | if (ret) | |
169 | return ret; | |
170 | ||
f3f096cf | 171 | list_del(&tu->list); |
f3f096cf | 172 | free_trace_uprobe(tu); |
c6c2401d | 173 | return 0; |
f3f096cf SD |
174 | } |
175 | ||
176 | /* Register a trace_uprobe and probe_event */ | |
177 | static int register_trace_uprobe(struct trace_uprobe *tu) | |
178 | { | |
14577c39 | 179 | struct trace_uprobe *old_tu; |
f3f096cf SD |
180 | int ret; |
181 | ||
182 | mutex_lock(&uprobe_lock); | |
183 | ||
184 | /* register as an event */ | |
14577c39 NK |
185 | old_tu = find_probe_event(tu->tp.call.name, tu->tp.call.class->system); |
186 | if (old_tu) { | |
f3f096cf | 187 | /* delete old event */ |
14577c39 | 188 | ret = unregister_trace_uprobe(old_tu); |
c6c2401d SRRH |
189 | if (ret) |
190 | goto end; | |
191 | } | |
f3f096cf SD |
192 | |
193 | ret = register_uprobe_event(tu); | |
194 | if (ret) { | |
195 | pr_warning("Failed to register probe event(%d)\n", ret); | |
196 | goto end; | |
197 | } | |
198 | ||
199 | list_add_tail(&tu->list, &uprobe_list); | |
200 | ||
201 | end: | |
202 | mutex_unlock(&uprobe_lock); | |
203 | ||
204 | return ret; | |
205 | } | |
206 | ||
207 | /* | |
208 | * Argument syntax: | |
306cfe20 | 209 | * - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS] |
f3f096cf SD |
210 | * |
211 | * - Remove uprobe: -:[GRP/]EVENT | |
212 | */ | |
213 | static int create_trace_uprobe(int argc, char **argv) | |
214 | { | |
215 | struct trace_uprobe *tu; | |
216 | struct inode *inode; | |
217 | char *arg, *event, *group, *filename; | |
218 | char buf[MAX_EVENT_NAME_LEN]; | |
219 | struct path path; | |
220 | unsigned long offset; | |
4ee5a52e | 221 | bool is_delete, is_return; |
f3f096cf SD |
222 | int i, ret; |
223 | ||
224 | inode = NULL; | |
225 | ret = 0; | |
226 | is_delete = false; | |
4ee5a52e | 227 | is_return = false; |
f3f096cf SD |
228 | event = NULL; |
229 | group = NULL; | |
230 | ||
231 | /* argc must be >= 1 */ | |
232 | if (argv[0][0] == '-') | |
233 | is_delete = true; | |
4ee5a52e ON |
234 | else if (argv[0][0] == 'r') |
235 | is_return = true; | |
f3f096cf | 236 | else if (argv[0][0] != 'p') { |
4ee5a52e | 237 | pr_info("Probe definition must be started with 'p', 'r' or '-'.\n"); |
f3f096cf SD |
238 | return -EINVAL; |
239 | } | |
240 | ||
241 | if (argv[0][1] == ':') { | |
242 | event = &argv[0][2]; | |
243 | arg = strchr(event, '/'); | |
244 | ||
245 | if (arg) { | |
246 | group = event; | |
247 | event = arg + 1; | |
248 | event[-1] = '\0'; | |
249 | ||
250 | if (strlen(group) == 0) { | |
251 | pr_info("Group name is not specified\n"); | |
252 | return -EINVAL; | |
253 | } | |
254 | } | |
255 | if (strlen(event) == 0) { | |
256 | pr_info("Event name is not specified\n"); | |
257 | return -EINVAL; | |
258 | } | |
259 | } | |
260 | if (!group) | |
261 | group = UPROBE_EVENT_SYSTEM; | |
262 | ||
263 | if (is_delete) { | |
c6c2401d SRRH |
264 | int ret; |
265 | ||
f3f096cf SD |
266 | if (!event) { |
267 | pr_info("Delete command needs an event name.\n"); | |
268 | return -EINVAL; | |
269 | } | |
270 | mutex_lock(&uprobe_lock); | |
271 | tu = find_probe_event(event, group); | |
272 | ||
273 | if (!tu) { | |
274 | mutex_unlock(&uprobe_lock); | |
275 | pr_info("Event %s/%s doesn't exist.\n", group, event); | |
276 | return -ENOENT; | |
277 | } | |
278 | /* delete an event */ | |
c6c2401d | 279 | ret = unregister_trace_uprobe(tu); |
f3f096cf | 280 | mutex_unlock(&uprobe_lock); |
c6c2401d | 281 | return ret; |
f3f096cf SD |
282 | } |
283 | ||
284 | if (argc < 2) { | |
285 | pr_info("Probe point is not specified.\n"); | |
286 | return -EINVAL; | |
287 | } | |
288 | if (isdigit(argv[1][0])) { | |
289 | pr_info("probe point must be have a filename.\n"); | |
290 | return -EINVAL; | |
291 | } | |
292 | arg = strchr(argv[1], ':'); | |
fa44063f J |
293 | if (!arg) { |
294 | ret = -EINVAL; | |
f3f096cf | 295 | goto fail_address_parse; |
fa44063f | 296 | } |
f3f096cf SD |
297 | |
298 | *arg++ = '\0'; | |
299 | filename = argv[1]; | |
300 | ret = kern_path(filename, LOOKUP_FOLLOW, &path); | |
301 | if (ret) | |
302 | goto fail_address_parse; | |
303 | ||
f3f096cf | 304 | inode = igrab(path.dentry->d_inode); |
84d7ed79 ON |
305 | path_put(&path); |
306 | ||
7e4e28c5 | 307 | if (!inode || !S_ISREG(inode->i_mode)) { |
d24d7dbf JZ |
308 | ret = -EINVAL; |
309 | goto fail_address_parse; | |
310 | } | |
f3f096cf | 311 | |
84d7ed79 ON |
312 | ret = kstrtoul(arg, 0, &offset); |
313 | if (ret) | |
314 | goto fail_address_parse; | |
315 | ||
f3f096cf SD |
316 | argc -= 2; |
317 | argv += 2; | |
318 | ||
319 | /* setup a probe */ | |
320 | if (!event) { | |
b2e902f0 | 321 | char *tail; |
f3f096cf SD |
322 | char *ptr; |
323 | ||
b2e902f0 AS |
324 | tail = kstrdup(kbasename(filename), GFP_KERNEL); |
325 | if (!tail) { | |
f3f096cf SD |
326 | ret = -ENOMEM; |
327 | goto fail_address_parse; | |
328 | } | |
329 | ||
f3f096cf SD |
330 | ptr = strpbrk(tail, ".-_"); |
331 | if (ptr) | |
332 | *ptr = '\0'; | |
333 | ||
334 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset); | |
335 | event = buf; | |
336 | kfree(tail); | |
337 | } | |
338 | ||
4ee5a52e | 339 | tu = alloc_trace_uprobe(group, event, argc, is_return); |
f3f096cf SD |
340 | if (IS_ERR(tu)) { |
341 | pr_info("Failed to allocate trace_uprobe.(%d)\n", (int)PTR_ERR(tu)); | |
342 | ret = PTR_ERR(tu); | |
343 | goto fail_address_parse; | |
344 | } | |
345 | tu->offset = offset; | |
346 | tu->inode = inode; | |
347 | tu->filename = kstrdup(filename, GFP_KERNEL); | |
348 | ||
349 | if (!tu->filename) { | |
350 | pr_info("Failed to allocate filename.\n"); | |
351 | ret = -ENOMEM; | |
352 | goto error; | |
353 | } | |
354 | ||
355 | /* parse arguments */ | |
356 | ret = 0; | |
357 | for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { | |
14577c39 NK |
358 | struct probe_arg *parg = &tu->tp.args[i]; |
359 | ||
f3f096cf | 360 | /* Increment count for freeing args in error case */ |
14577c39 | 361 | tu->tp.nr_args++; |
f3f096cf SD |
362 | |
363 | /* Parse argument name */ | |
364 | arg = strchr(argv[i], '='); | |
365 | if (arg) { | |
366 | *arg++ = '\0'; | |
14577c39 | 367 | parg->name = kstrdup(argv[i], GFP_KERNEL); |
f3f096cf SD |
368 | } else { |
369 | arg = argv[i]; | |
370 | /* If argument name is omitted, set "argN" */ | |
371 | snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1); | |
14577c39 | 372 | parg->name = kstrdup(buf, GFP_KERNEL); |
f3f096cf SD |
373 | } |
374 | ||
14577c39 | 375 | if (!parg->name) { |
f3f096cf SD |
376 | pr_info("Failed to allocate argument[%d] name.\n", i); |
377 | ret = -ENOMEM; | |
378 | goto error; | |
379 | } | |
380 | ||
14577c39 NK |
381 | if (!is_good_name(parg->name)) { |
382 | pr_info("Invalid argument[%d] name: %s\n", i, parg->name); | |
f3f096cf SD |
383 | ret = -EINVAL; |
384 | goto error; | |
385 | } | |
386 | ||
14577c39 | 387 | if (traceprobe_conflict_field_name(parg->name, tu->tp.args, i)) { |
f3f096cf SD |
388 | pr_info("Argument[%d] name '%s' conflicts with " |
389 | "another field.\n", i, argv[i]); | |
390 | ret = -EINVAL; | |
391 | goto error; | |
392 | } | |
393 | ||
394 | /* Parse fetch argument */ | |
14577c39 NK |
395 | ret = traceprobe_parse_probe_arg(arg, &tu->tp.size, parg, |
396 | false, false); | |
f3f096cf SD |
397 | if (ret) { |
398 | pr_info("Parse error at argument[%d]. (%d)\n", i, ret); | |
399 | goto error; | |
400 | } | |
401 | } | |
402 | ||
403 | ret = register_trace_uprobe(tu); | |
404 | if (ret) | |
405 | goto error; | |
406 | return 0; | |
407 | ||
408 | error: | |
409 | free_trace_uprobe(tu); | |
410 | return ret; | |
411 | ||
412 | fail_address_parse: | |
413 | if (inode) | |
414 | iput(inode); | |
415 | ||
d24d7dbf | 416 | pr_info("Failed to parse address or file.\n"); |
f3f096cf SD |
417 | |
418 | return ret; | |
419 | } | |
420 | ||
c6c2401d | 421 | static int cleanup_all_probes(void) |
f3f096cf SD |
422 | { |
423 | struct trace_uprobe *tu; | |
c6c2401d | 424 | int ret = 0; |
f3f096cf SD |
425 | |
426 | mutex_lock(&uprobe_lock); | |
427 | while (!list_empty(&uprobe_list)) { | |
428 | tu = list_entry(uprobe_list.next, struct trace_uprobe, list); | |
c6c2401d SRRH |
429 | ret = unregister_trace_uprobe(tu); |
430 | if (ret) | |
431 | break; | |
f3f096cf SD |
432 | } |
433 | mutex_unlock(&uprobe_lock); | |
c6c2401d | 434 | return ret; |
f3f096cf SD |
435 | } |
436 | ||
437 | /* Probes listing interfaces */ | |
438 | static void *probes_seq_start(struct seq_file *m, loff_t *pos) | |
439 | { | |
440 | mutex_lock(&uprobe_lock); | |
441 | return seq_list_start(&uprobe_list, *pos); | |
442 | } | |
443 | ||
444 | static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos) | |
445 | { | |
446 | return seq_list_next(v, &uprobe_list, pos); | |
447 | } | |
448 | ||
449 | static void probes_seq_stop(struct seq_file *m, void *v) | |
450 | { | |
451 | mutex_unlock(&uprobe_lock); | |
452 | } | |
453 | ||
454 | static int probes_seq_show(struct seq_file *m, void *v) | |
455 | { | |
456 | struct trace_uprobe *tu = v; | |
3ede82dd | 457 | char c = is_ret_probe(tu) ? 'r' : 'p'; |
f3f096cf SD |
458 | int i; |
459 | ||
14577c39 | 460 | seq_printf(m, "%c:%s/%s", c, tu->tp.call.class->system, tu->tp.call.name); |
f3f096cf SD |
461 | seq_printf(m, " %s:0x%p", tu->filename, (void *)tu->offset); |
462 | ||
14577c39 NK |
463 | for (i = 0; i < tu->tp.nr_args; i++) |
464 | seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm); | |
f3f096cf SD |
465 | |
466 | seq_printf(m, "\n"); | |
467 | return 0; | |
468 | } | |
469 | ||
470 | static const struct seq_operations probes_seq_op = { | |
471 | .start = probes_seq_start, | |
472 | .next = probes_seq_next, | |
473 | .stop = probes_seq_stop, | |
474 | .show = probes_seq_show | |
475 | }; | |
476 | ||
477 | static int probes_open(struct inode *inode, struct file *file) | |
478 | { | |
c6c2401d SRRH |
479 | int ret; |
480 | ||
481 | if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { | |
482 | ret = cleanup_all_probes(); | |
483 | if (ret) | |
484 | return ret; | |
485 | } | |
f3f096cf SD |
486 | |
487 | return seq_open(file, &probes_seq_op); | |
488 | } | |
489 | ||
490 | static ssize_t probes_write(struct file *file, const char __user *buffer, | |
491 | size_t count, loff_t *ppos) | |
492 | { | |
493 | return traceprobe_probes_write(file, buffer, count, ppos, create_trace_uprobe); | |
494 | } | |
495 | ||
496 | static const struct file_operations uprobe_events_ops = { | |
497 | .owner = THIS_MODULE, | |
498 | .open = probes_open, | |
499 | .read = seq_read, | |
500 | .llseek = seq_lseek, | |
501 | .release = seq_release, | |
502 | .write = probes_write, | |
503 | }; | |
504 | ||
505 | /* Probes profiling interfaces */ | |
506 | static int probes_profile_seq_show(struct seq_file *m, void *v) | |
507 | { | |
508 | struct trace_uprobe *tu = v; | |
509 | ||
14577c39 | 510 | seq_printf(m, " %s %-44s %15lu\n", tu->filename, tu->tp.call.name, tu->nhit); |
f3f096cf SD |
511 | return 0; |
512 | } | |
513 | ||
514 | static const struct seq_operations profile_seq_op = { | |
515 | .start = probes_seq_start, | |
516 | .next = probes_seq_next, | |
517 | .stop = probes_seq_stop, | |
518 | .show = probes_profile_seq_show | |
519 | }; | |
520 | ||
521 | static int profile_open(struct inode *inode, struct file *file) | |
522 | { | |
523 | return seq_open(file, &profile_seq_op); | |
524 | } | |
525 | ||
526 | static const struct file_operations uprobe_profile_ops = { | |
527 | .owner = THIS_MODULE, | |
528 | .open = profile_open, | |
529 | .read = seq_read, | |
530 | .llseek = seq_lseek, | |
531 | .release = seq_release, | |
532 | }; | |
533 | ||
a51cc604 ON |
534 | static void uprobe_trace_print(struct trace_uprobe *tu, |
535 | unsigned long func, struct pt_regs *regs) | |
f3f096cf SD |
536 | { |
537 | struct uprobe_trace_entry_head *entry; | |
538 | struct ring_buffer_event *event; | |
539 | struct ring_buffer *buffer; | |
457d1772 | 540 | void *data; |
0e3853d2 | 541 | int size, i; |
14577c39 | 542 | struct ftrace_event_call *call = &tu->tp.call; |
f3f096cf | 543 | |
393a736c | 544 | size = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); |
f3f096cf | 545 | event = trace_current_buffer_lock_reserve(&buffer, call->event.type, |
14577c39 | 546 | size + tu->tp.size, 0, 0); |
f3f096cf | 547 | if (!event) |
a51cc604 | 548 | return; |
f3f096cf SD |
549 | |
550 | entry = ring_buffer_event_data(event); | |
393a736c ON |
551 | if (is_ret_probe(tu)) { |
552 | entry->vaddr[0] = func; | |
553 | entry->vaddr[1] = instruction_pointer(regs); | |
554 | data = DATAOF_TRACE_ENTRY(entry, true); | |
555 | } else { | |
556 | entry->vaddr[0] = instruction_pointer(regs); | |
557 | data = DATAOF_TRACE_ENTRY(entry, false); | |
558 | } | |
559 | ||
14577c39 NK |
560 | for (i = 0; i < tu->tp.nr_args; i++) { |
561 | call_fetch(&tu->tp.args[i].fetch, regs, | |
562 | data + tu->tp.args[i].offset); | |
563 | } | |
f3f096cf | 564 | |
f306cc82 | 565 | if (!call_filter_check_discard(call, entry, buffer, event)) |
0e3853d2 | 566 | trace_buffer_unlock_commit(buffer, event, 0, 0); |
a51cc604 | 567 | } |
f42d24a1 | 568 | |
a51cc604 ON |
569 | /* uprobe handler */ |
570 | static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs) | |
571 | { | |
393a736c ON |
572 | if (!is_ret_probe(tu)) |
573 | uprobe_trace_print(tu, 0, regs); | |
f42d24a1 | 574 | return 0; |
f3f096cf SD |
575 | } |
576 | ||
c1ae5c75 ON |
577 | static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func, |
578 | struct pt_regs *regs) | |
579 | { | |
580 | uprobe_trace_print(tu, func, regs); | |
581 | } | |
582 | ||
f3f096cf SD |
583 | /* Event entry printers */ |
584 | static enum print_line_t | |
585 | print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event) | |
586 | { | |
457d1772 | 587 | struct uprobe_trace_entry_head *entry; |
f3f096cf SD |
588 | struct trace_seq *s = &iter->seq; |
589 | struct trace_uprobe *tu; | |
590 | u8 *data; | |
591 | int i; | |
592 | ||
457d1772 | 593 | entry = (struct uprobe_trace_entry_head *)iter->ent; |
14577c39 | 594 | tu = container_of(event, struct trace_uprobe, tp.call.event); |
f3f096cf | 595 | |
3ede82dd | 596 | if (is_ret_probe(tu)) { |
14577c39 | 597 | if (!trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)", tu->tp.call.name, |
3ede82dd ON |
598 | entry->vaddr[1], entry->vaddr[0])) |
599 | goto partial; | |
600 | data = DATAOF_TRACE_ENTRY(entry, true); | |
601 | } else { | |
14577c39 | 602 | if (!trace_seq_printf(s, "%s: (0x%lx)", tu->tp.call.name, |
3ede82dd ON |
603 | entry->vaddr[0])) |
604 | goto partial; | |
605 | data = DATAOF_TRACE_ENTRY(entry, false); | |
606 | } | |
f3f096cf | 607 | |
14577c39 NK |
608 | for (i = 0; i < tu->tp.nr_args; i++) { |
609 | struct probe_arg *parg = &tu->tp.args[i]; | |
610 | ||
611 | if (!parg->type->print(s, parg->name, data + parg->offset, entry)) | |
f3f096cf SD |
612 | goto partial; |
613 | } | |
614 | ||
615 | if (trace_seq_puts(s, "\n")) | |
616 | return TRACE_TYPE_HANDLED; | |
617 | ||
618 | partial: | |
619 | return TRACE_TYPE_PARTIAL_LINE; | |
620 | } | |
621 | ||
31ba3348 ON |
622 | typedef bool (*filter_func_t)(struct uprobe_consumer *self, |
623 | enum uprobe_filter_ctx ctx, | |
624 | struct mm_struct *mm); | |
625 | ||
626 | static int | |
627 | probe_event_enable(struct trace_uprobe *tu, int flag, filter_func_t filter) | |
f3f096cf | 628 | { |
f3f096cf SD |
629 | int ret = 0; |
630 | ||
14577c39 | 631 | if (trace_probe_is_enabled(&tu->tp)) |
f3f096cf SD |
632 | return -EINTR; |
633 | ||
736288ba ON |
634 | WARN_ON(!uprobe_filter_is_empty(&tu->filter)); |
635 | ||
14577c39 | 636 | tu->tp.flags |= flag; |
31ba3348 | 637 | tu->consumer.filter = filter; |
a932b738 ON |
638 | ret = uprobe_register(tu->inode, tu->offset, &tu->consumer); |
639 | if (ret) | |
14577c39 | 640 | tu->tp.flags &= ~flag; |
f3f096cf | 641 | |
4161824f | 642 | return ret; |
f3f096cf SD |
643 | } |
644 | ||
645 | static void probe_event_disable(struct trace_uprobe *tu, int flag) | |
646 | { | |
14577c39 | 647 | if (!trace_probe_is_enabled(&tu->tp)) |
f3f096cf SD |
648 | return; |
649 | ||
736288ba ON |
650 | WARN_ON(!uprobe_filter_is_empty(&tu->filter)); |
651 | ||
a932b738 | 652 | uprobe_unregister(tu->inode, tu->offset, &tu->consumer); |
14577c39 | 653 | tu->tp.flags &= ~flag; |
f3f096cf SD |
654 | } |
655 | ||
656 | static int uprobe_event_define_fields(struct ftrace_event_call *event_call) | |
657 | { | |
457d1772 | 658 | int ret, i, size; |
f3f096cf | 659 | struct uprobe_trace_entry_head field; |
457d1772 | 660 | struct trace_uprobe *tu = event_call->data; |
f3f096cf | 661 | |
4d1298e2 ON |
662 | if (is_ret_probe(tu)) { |
663 | DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0); | |
664 | DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0); | |
665 | size = SIZEOF_TRACE_ENTRY(true); | |
666 | } else { | |
667 | DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0); | |
668 | size = SIZEOF_TRACE_ENTRY(false); | |
669 | } | |
f3f096cf | 670 | /* Set argument names as fields */ |
14577c39 NK |
671 | for (i = 0; i < tu->tp.nr_args; i++) { |
672 | struct probe_arg *parg = &tu->tp.args[i]; | |
673 | ||
674 | ret = trace_define_field(event_call, parg->type->fmttype, | |
675 | parg->name, size + parg->offset, | |
676 | parg->type->size, parg->type->is_signed, | |
f3f096cf SD |
677 | FILTER_OTHER); |
678 | ||
679 | if (ret) | |
680 | return ret; | |
681 | } | |
682 | return 0; | |
683 | } | |
684 | ||
685 | #define LEN_OR_ZERO (len ? len - pos : 0) | |
686 | static int __set_print_fmt(struct trace_uprobe *tu, char *buf, int len) | |
687 | { | |
688 | const char *fmt, *arg; | |
689 | int i; | |
690 | int pos = 0; | |
691 | ||
4d1298e2 ON |
692 | if (is_ret_probe(tu)) { |
693 | fmt = "(%lx <- %lx)"; | |
694 | arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP; | |
695 | } else { | |
696 | fmt = "(%lx)"; | |
697 | arg = "REC->" FIELD_STRING_IP; | |
698 | } | |
f3f096cf SD |
699 | |
700 | /* When len=0, we just calculate the needed length */ | |
701 | ||
702 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt); | |
703 | ||
14577c39 | 704 | for (i = 0; i < tu->tp.nr_args; i++) { |
f3f096cf | 705 | pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s", |
14577c39 | 706 | tu->tp.args[i].name, tu->tp.args[i].type->fmt); |
f3f096cf SD |
707 | } |
708 | ||
709 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg); | |
710 | ||
14577c39 | 711 | for (i = 0; i < tu->tp.nr_args; i++) { |
f3f096cf | 712 | pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s", |
14577c39 | 713 | tu->tp.args[i].name); |
f3f096cf SD |
714 | } |
715 | ||
716 | return pos; /* return the length of print_fmt */ | |
717 | } | |
718 | #undef LEN_OR_ZERO | |
719 | ||
720 | static int set_print_fmt(struct trace_uprobe *tu) | |
721 | { | |
722 | char *print_fmt; | |
723 | int len; | |
724 | ||
725 | /* First: called with 0 length to calculate the needed length */ | |
726 | len = __set_print_fmt(tu, NULL, 0); | |
727 | print_fmt = kmalloc(len + 1, GFP_KERNEL); | |
728 | if (!print_fmt) | |
729 | return -ENOMEM; | |
730 | ||
731 | /* Second: actually write the @print_fmt */ | |
732 | __set_print_fmt(tu, print_fmt, len + 1); | |
14577c39 | 733 | tu->tp.call.print_fmt = print_fmt; |
f3f096cf SD |
734 | |
735 | return 0; | |
736 | } | |
737 | ||
738 | #ifdef CONFIG_PERF_EVENTS | |
31ba3348 ON |
739 | static bool |
740 | __uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm) | |
741 | { | |
742 | struct perf_event *event; | |
743 | ||
744 | if (filter->nr_systemwide) | |
745 | return true; | |
746 | ||
747 | list_for_each_entry(event, &filter->perf_events, hw.tp_list) { | |
748 | if (event->hw.tp_target->mm == mm) | |
749 | return true; | |
750 | } | |
751 | ||
752 | return false; | |
753 | } | |
754 | ||
b2fe8ba6 ON |
755 | static inline bool |
756 | uprobe_filter_event(struct trace_uprobe *tu, struct perf_event *event) | |
757 | { | |
758 | return __uprobe_perf_filter(&tu->filter, event->hw.tp_target->mm); | |
759 | } | |
760 | ||
736288ba ON |
761 | static int uprobe_perf_open(struct trace_uprobe *tu, struct perf_event *event) |
762 | { | |
b2fe8ba6 ON |
763 | bool done; |
764 | ||
736288ba | 765 | write_lock(&tu->filter.rwlock); |
b2fe8ba6 ON |
766 | if (event->hw.tp_target) { |
767 | /* | |
768 | * event->parent != NULL means copy_process(), we can avoid | |
769 | * uprobe_apply(). current->mm must be probed and we can rely | |
770 | * on dup_mmap() which preserves the already installed bp's. | |
771 | * | |
772 | * attr.enable_on_exec means that exec/mmap will install the | |
773 | * breakpoints we need. | |
774 | */ | |
775 | done = tu->filter.nr_systemwide || | |
776 | event->parent || event->attr.enable_on_exec || | |
777 | uprobe_filter_event(tu, event); | |
736288ba | 778 | list_add(&event->hw.tp_list, &tu->filter.perf_events); |
b2fe8ba6 ON |
779 | } else { |
780 | done = tu->filter.nr_systemwide; | |
736288ba | 781 | tu->filter.nr_systemwide++; |
b2fe8ba6 | 782 | } |
736288ba ON |
783 | write_unlock(&tu->filter.rwlock); |
784 | ||
b2fe8ba6 ON |
785 | if (!done) |
786 | uprobe_apply(tu->inode, tu->offset, &tu->consumer, true); | |
31ba3348 | 787 | |
736288ba ON |
788 | return 0; |
789 | } | |
790 | ||
791 | static int uprobe_perf_close(struct trace_uprobe *tu, struct perf_event *event) | |
792 | { | |
b2fe8ba6 ON |
793 | bool done; |
794 | ||
736288ba | 795 | write_lock(&tu->filter.rwlock); |
b2fe8ba6 | 796 | if (event->hw.tp_target) { |
736288ba | 797 | list_del(&event->hw.tp_list); |
b2fe8ba6 ON |
798 | done = tu->filter.nr_systemwide || |
799 | (event->hw.tp_target->flags & PF_EXITING) || | |
800 | uprobe_filter_event(tu, event); | |
801 | } else { | |
736288ba | 802 | tu->filter.nr_systemwide--; |
b2fe8ba6 ON |
803 | done = tu->filter.nr_systemwide; |
804 | } | |
736288ba ON |
805 | write_unlock(&tu->filter.rwlock); |
806 | ||
b2fe8ba6 ON |
807 | if (!done) |
808 | uprobe_apply(tu->inode, tu->offset, &tu->consumer, false); | |
31ba3348 | 809 | |
736288ba ON |
810 | return 0; |
811 | } | |
812 | ||
31ba3348 ON |
813 | static bool uprobe_perf_filter(struct uprobe_consumer *uc, |
814 | enum uprobe_filter_ctx ctx, struct mm_struct *mm) | |
815 | { | |
816 | struct trace_uprobe *tu; | |
817 | int ret; | |
818 | ||
819 | tu = container_of(uc, struct trace_uprobe, consumer); | |
820 | read_lock(&tu->filter.rwlock); | |
821 | ret = __uprobe_perf_filter(&tu->filter, mm); | |
822 | read_unlock(&tu->filter.rwlock); | |
823 | ||
824 | return ret; | |
825 | } | |
826 | ||
a51cc604 ON |
827 | static void uprobe_perf_print(struct trace_uprobe *tu, |
828 | unsigned long func, struct pt_regs *regs) | |
f3f096cf | 829 | { |
14577c39 | 830 | struct ftrace_event_call *call = &tu->tp.call; |
f3f096cf SD |
831 | struct uprobe_trace_entry_head *entry; |
832 | struct hlist_head *head; | |
457d1772 ON |
833 | void *data; |
834 | int size, rctx, i; | |
f3f096cf | 835 | |
393a736c | 836 | size = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); |
14577c39 | 837 | size = ALIGN(size + tu->tp.size + sizeof(u32), sizeof(u64)) - sizeof(u32); |
f3f096cf SD |
838 | |
839 | preempt_disable(); | |
515619f2 ON |
840 | head = this_cpu_ptr(call->perf_events); |
841 | if (hlist_empty(head)) | |
842 | goto out; | |
843 | ||
f3f096cf SD |
844 | entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx); |
845 | if (!entry) | |
846 | goto out; | |
847 | ||
393a736c ON |
848 | if (is_ret_probe(tu)) { |
849 | entry->vaddr[0] = func; | |
32520b2c | 850 | entry->vaddr[1] = instruction_pointer(regs); |
393a736c ON |
851 | data = DATAOF_TRACE_ENTRY(entry, true); |
852 | } else { | |
32520b2c | 853 | entry->vaddr[0] = instruction_pointer(regs); |
393a736c ON |
854 | data = DATAOF_TRACE_ENTRY(entry, false); |
855 | } | |
856 | ||
14577c39 NK |
857 | for (i = 0; i < tu->tp.nr_args; i++) { |
858 | struct probe_arg *parg = &tu->tp.args[i]; | |
859 | ||
860 | call_fetch(&parg->fetch, regs, data + parg->offset); | |
861 | } | |
f3f096cf | 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 | 927 | |
14577c39 | 928 | if (tu->tp.flags & TP_FLAG_TRACE) |
f42d24a1 | 929 | ret |= uprobe_trace_func(tu, regs); |
f3f096cf SD |
930 | |
931 | #ifdef CONFIG_PERF_EVENTS | |
14577c39 | 932 | if (tu->tp.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 | ||
14577c39 | 945 | if (tu->tp.flags & TP_FLAG_TRACE) |
c1ae5c75 ON |
946 | uretprobe_trace_func(tu, func, regs); |
947 | ||
948 | #ifdef CONFIG_PERF_EVENTS | |
14577c39 | 949 | if (tu->tp.flags & TP_FLAG_PROFILE) |
c1ae5c75 ON |
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 | { | |
14577c39 | 961 | struct ftrace_event_call *call = &tu->tp.call; |
f3f096cf SD |
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() */ |
14577c39 | 996 | ret = trace_remove_event_call(&tu->tp.call); |
c6c2401d SRRH |
997 | if (ret) |
998 | return ret; | |
14577c39 NK |
999 | kfree(tu->tp.call.print_fmt); |
1000 | tu->tp.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); |