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; | |
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 | |
3fd996a2 NK |
77 | #ifdef CONFIG_STACK_GROWSUP |
78 | static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n) | |
79 | { | |
80 | return addr - (n * sizeof(long)); | |
81 | } | |
82 | #else | |
83 | static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n) | |
84 | { | |
85 | return addr + (n * sizeof(long)); | |
86 | } | |
87 | #endif | |
88 | ||
89 | static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n) | |
90 | { | |
91 | unsigned long ret; | |
92 | unsigned long addr = user_stack_pointer(regs); | |
93 | ||
94 | addr = adjust_stack_addr(addr, n); | |
95 | ||
96 | if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret))) | |
97 | return 0; | |
98 | ||
99 | return ret; | |
100 | } | |
101 | ||
102 | /* | |
103 | * Uprobes-specific fetch functions | |
104 | */ | |
105 | #define DEFINE_FETCH_stack(type) \ | |
106 | static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\ | |
107 | void *offset, void *dest) \ | |
108 | { \ | |
109 | *(type *)dest = (type)get_user_stack_nth(regs, \ | |
110 | ((unsigned long)offset)); \ | |
111 | } | |
112 | DEFINE_BASIC_FETCH_FUNCS(stack) | |
113 | /* No string on the stack entry */ | |
114 | #define fetch_stack_string NULL | |
115 | #define fetch_stack_string_size NULL | |
116 | ||
117 | ||
1301a44e NK |
118 | /* uprobes do not support symbol fetch methods */ |
119 | #define fetch_symbol_u8 NULL | |
120 | #define fetch_symbol_u16 NULL | |
121 | #define fetch_symbol_u32 NULL | |
122 | #define fetch_symbol_u64 NULL | |
123 | #define fetch_symbol_string NULL | |
124 | #define fetch_symbol_string_size NULL | |
125 | ||
34fee3a1 NK |
126 | /* Fetch type information table */ |
127 | const struct fetch_type uprobes_fetch_type_table[] = { | |
128 | /* Special types */ | |
129 | [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string, | |
130 | sizeof(u32), 1, "__data_loc char[]"), | |
131 | [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32, | |
132 | string_size, sizeof(u32), 0, "u32"), | |
133 | /* Basic types */ | |
134 | ASSIGN_FETCH_TYPE(u8, u8, 0), | |
135 | ASSIGN_FETCH_TYPE(u16, u16, 0), | |
136 | ASSIGN_FETCH_TYPE(u32, u32, 0), | |
137 | ASSIGN_FETCH_TYPE(u64, u64, 0), | |
138 | ASSIGN_FETCH_TYPE(s8, u8, 1), | |
139 | ASSIGN_FETCH_TYPE(s16, u16, 1), | |
140 | ASSIGN_FETCH_TYPE(s32, u32, 1), | |
141 | ASSIGN_FETCH_TYPE(s64, u64, 1), | |
142 | ||
143 | ASSIGN_FETCH_TYPE_END | |
144 | }; | |
145 | ||
736288ba ON |
146 | static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter) |
147 | { | |
148 | rwlock_init(&filter->rwlock); | |
149 | filter->nr_systemwide = 0; | |
150 | INIT_LIST_HEAD(&filter->perf_events); | |
151 | } | |
152 | ||
153 | static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter) | |
154 | { | |
155 | return !filter->nr_systemwide && list_empty(&filter->perf_events); | |
156 | } | |
157 | ||
c1ae5c75 ON |
158 | static inline bool is_ret_probe(struct trace_uprobe *tu) |
159 | { | |
160 | return tu->consumer.ret_handler != NULL; | |
161 | } | |
162 | ||
f3f096cf SD |
163 | /* |
164 | * Allocate new trace_uprobe and initialize it (including uprobes). | |
165 | */ | |
166 | static struct trace_uprobe * | |
c1ae5c75 | 167 | alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret) |
f3f096cf SD |
168 | { |
169 | struct trace_uprobe *tu; | |
170 | ||
171 | if (!event || !is_good_name(event)) | |
172 | return ERR_PTR(-EINVAL); | |
173 | ||
174 | if (!group || !is_good_name(group)) | |
175 | return ERR_PTR(-EINVAL); | |
176 | ||
177 | tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL); | |
178 | if (!tu) | |
179 | return ERR_PTR(-ENOMEM); | |
180 | ||
14577c39 NK |
181 | tu->tp.call.class = &tu->tp.class; |
182 | tu->tp.call.name = kstrdup(event, GFP_KERNEL); | |
183 | if (!tu->tp.call.name) | |
f3f096cf SD |
184 | goto error; |
185 | ||
14577c39 NK |
186 | tu->tp.class.system = kstrdup(group, GFP_KERNEL); |
187 | if (!tu->tp.class.system) | |
f3f096cf SD |
188 | goto error; |
189 | ||
190 | INIT_LIST_HEAD(&tu->list); | |
a932b738 | 191 | tu->consumer.handler = uprobe_dispatcher; |
c1ae5c75 ON |
192 | if (is_ret) |
193 | tu->consumer.ret_handler = uretprobe_dispatcher; | |
736288ba | 194 | init_trace_uprobe_filter(&tu->filter); |
14577c39 | 195 | tu->tp.call.flags |= TRACE_EVENT_FL_USE_CALL_FILTER; |
f3f096cf SD |
196 | return tu; |
197 | ||
198 | error: | |
14577c39 | 199 | kfree(tu->tp.call.name); |
f3f096cf SD |
200 | kfree(tu); |
201 | ||
202 | return ERR_PTR(-ENOMEM); | |
203 | } | |
204 | ||
205 | static void free_trace_uprobe(struct trace_uprobe *tu) | |
206 | { | |
207 | int i; | |
208 | ||
14577c39 NK |
209 | for (i = 0; i < tu->tp.nr_args; i++) |
210 | traceprobe_free_probe_arg(&tu->tp.args[i]); | |
f3f096cf SD |
211 | |
212 | iput(tu->inode); | |
14577c39 NK |
213 | kfree(tu->tp.call.class->system); |
214 | kfree(tu->tp.call.name); | |
f3f096cf SD |
215 | kfree(tu->filename); |
216 | kfree(tu); | |
217 | } | |
218 | ||
219 | static struct trace_uprobe *find_probe_event(const char *event, const char *group) | |
220 | { | |
221 | struct trace_uprobe *tu; | |
222 | ||
223 | list_for_each_entry(tu, &uprobe_list, list) | |
14577c39 NK |
224 | if (strcmp(tu->tp.call.name, event) == 0 && |
225 | strcmp(tu->tp.call.class->system, group) == 0) | |
f3f096cf SD |
226 | return tu; |
227 | ||
228 | return NULL; | |
229 | } | |
230 | ||
231 | /* Unregister a trace_uprobe and probe_event: call with locking uprobe_lock */ | |
c6c2401d | 232 | static int unregister_trace_uprobe(struct trace_uprobe *tu) |
f3f096cf | 233 | { |
c6c2401d SRRH |
234 | int ret; |
235 | ||
236 | ret = unregister_uprobe_event(tu); | |
237 | if (ret) | |
238 | return ret; | |
239 | ||
f3f096cf | 240 | list_del(&tu->list); |
f3f096cf | 241 | free_trace_uprobe(tu); |
c6c2401d | 242 | return 0; |
f3f096cf SD |
243 | } |
244 | ||
245 | /* Register a trace_uprobe and probe_event */ | |
246 | static int register_trace_uprobe(struct trace_uprobe *tu) | |
247 | { | |
14577c39 | 248 | struct trace_uprobe *old_tu; |
f3f096cf SD |
249 | int ret; |
250 | ||
251 | mutex_lock(&uprobe_lock); | |
252 | ||
253 | /* register as an event */ | |
14577c39 NK |
254 | old_tu = find_probe_event(tu->tp.call.name, tu->tp.call.class->system); |
255 | if (old_tu) { | |
f3f096cf | 256 | /* delete old event */ |
14577c39 | 257 | ret = unregister_trace_uprobe(old_tu); |
c6c2401d SRRH |
258 | if (ret) |
259 | goto end; | |
260 | } | |
f3f096cf SD |
261 | |
262 | ret = register_uprobe_event(tu); | |
263 | if (ret) { | |
264 | pr_warning("Failed to register probe event(%d)\n", ret); | |
265 | goto end; | |
266 | } | |
267 | ||
268 | list_add_tail(&tu->list, &uprobe_list); | |
269 | ||
270 | end: | |
271 | mutex_unlock(&uprobe_lock); | |
272 | ||
273 | return ret; | |
274 | } | |
275 | ||
276 | /* | |
277 | * Argument syntax: | |
306cfe20 | 278 | * - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS] |
f3f096cf SD |
279 | * |
280 | * - Remove uprobe: -:[GRP/]EVENT | |
281 | */ | |
282 | static int create_trace_uprobe(int argc, char **argv) | |
283 | { | |
284 | struct trace_uprobe *tu; | |
285 | struct inode *inode; | |
286 | char *arg, *event, *group, *filename; | |
287 | char buf[MAX_EVENT_NAME_LEN]; | |
288 | struct path path; | |
289 | unsigned long offset; | |
4ee5a52e | 290 | bool is_delete, is_return; |
f3f096cf SD |
291 | int i, ret; |
292 | ||
293 | inode = NULL; | |
294 | ret = 0; | |
295 | is_delete = false; | |
4ee5a52e | 296 | is_return = false; |
f3f096cf SD |
297 | event = NULL; |
298 | group = NULL; | |
299 | ||
300 | /* argc must be >= 1 */ | |
301 | if (argv[0][0] == '-') | |
302 | is_delete = true; | |
4ee5a52e ON |
303 | else if (argv[0][0] == 'r') |
304 | is_return = true; | |
f3f096cf | 305 | else if (argv[0][0] != 'p') { |
4ee5a52e | 306 | pr_info("Probe definition must be started with 'p', 'r' or '-'.\n"); |
f3f096cf SD |
307 | return -EINVAL; |
308 | } | |
309 | ||
310 | if (argv[0][1] == ':') { | |
311 | event = &argv[0][2]; | |
312 | arg = strchr(event, '/'); | |
313 | ||
314 | if (arg) { | |
315 | group = event; | |
316 | event = arg + 1; | |
317 | event[-1] = '\0'; | |
318 | ||
319 | if (strlen(group) == 0) { | |
320 | pr_info("Group name is not specified\n"); | |
321 | return -EINVAL; | |
322 | } | |
323 | } | |
324 | if (strlen(event) == 0) { | |
325 | pr_info("Event name is not specified\n"); | |
326 | return -EINVAL; | |
327 | } | |
328 | } | |
329 | if (!group) | |
330 | group = UPROBE_EVENT_SYSTEM; | |
331 | ||
332 | if (is_delete) { | |
c6c2401d SRRH |
333 | int ret; |
334 | ||
f3f096cf SD |
335 | if (!event) { |
336 | pr_info("Delete command needs an event name.\n"); | |
337 | return -EINVAL; | |
338 | } | |
339 | mutex_lock(&uprobe_lock); | |
340 | tu = find_probe_event(event, group); | |
341 | ||
342 | if (!tu) { | |
343 | mutex_unlock(&uprobe_lock); | |
344 | pr_info("Event %s/%s doesn't exist.\n", group, event); | |
345 | return -ENOENT; | |
346 | } | |
347 | /* delete an event */ | |
c6c2401d | 348 | ret = unregister_trace_uprobe(tu); |
f3f096cf | 349 | mutex_unlock(&uprobe_lock); |
c6c2401d | 350 | return ret; |
f3f096cf SD |
351 | } |
352 | ||
353 | if (argc < 2) { | |
354 | pr_info("Probe point is not specified.\n"); | |
355 | return -EINVAL; | |
356 | } | |
357 | if (isdigit(argv[1][0])) { | |
358 | pr_info("probe point must be have a filename.\n"); | |
359 | return -EINVAL; | |
360 | } | |
361 | arg = strchr(argv[1], ':'); | |
fa44063f J |
362 | if (!arg) { |
363 | ret = -EINVAL; | |
f3f096cf | 364 | goto fail_address_parse; |
fa44063f | 365 | } |
f3f096cf SD |
366 | |
367 | *arg++ = '\0'; | |
368 | filename = argv[1]; | |
369 | ret = kern_path(filename, LOOKUP_FOLLOW, &path); | |
370 | if (ret) | |
371 | goto fail_address_parse; | |
372 | ||
f3f096cf | 373 | inode = igrab(path.dentry->d_inode); |
84d7ed79 ON |
374 | path_put(&path); |
375 | ||
7e4e28c5 | 376 | if (!inode || !S_ISREG(inode->i_mode)) { |
d24d7dbf JZ |
377 | ret = -EINVAL; |
378 | goto fail_address_parse; | |
379 | } | |
f3f096cf | 380 | |
84d7ed79 ON |
381 | ret = kstrtoul(arg, 0, &offset); |
382 | if (ret) | |
383 | goto fail_address_parse; | |
384 | ||
f3f096cf SD |
385 | argc -= 2; |
386 | argv += 2; | |
387 | ||
388 | /* setup a probe */ | |
389 | if (!event) { | |
b2e902f0 | 390 | char *tail; |
f3f096cf SD |
391 | char *ptr; |
392 | ||
b2e902f0 AS |
393 | tail = kstrdup(kbasename(filename), GFP_KERNEL); |
394 | if (!tail) { | |
f3f096cf SD |
395 | ret = -ENOMEM; |
396 | goto fail_address_parse; | |
397 | } | |
398 | ||
f3f096cf SD |
399 | ptr = strpbrk(tail, ".-_"); |
400 | if (ptr) | |
401 | *ptr = '\0'; | |
402 | ||
403 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset); | |
404 | event = buf; | |
405 | kfree(tail); | |
406 | } | |
407 | ||
4ee5a52e | 408 | tu = alloc_trace_uprobe(group, event, argc, is_return); |
f3f096cf SD |
409 | if (IS_ERR(tu)) { |
410 | pr_info("Failed to allocate trace_uprobe.(%d)\n", (int)PTR_ERR(tu)); | |
411 | ret = PTR_ERR(tu); | |
412 | goto fail_address_parse; | |
413 | } | |
414 | tu->offset = offset; | |
415 | tu->inode = inode; | |
416 | tu->filename = kstrdup(filename, GFP_KERNEL); | |
417 | ||
418 | if (!tu->filename) { | |
419 | pr_info("Failed to allocate filename.\n"); | |
420 | ret = -ENOMEM; | |
421 | goto error; | |
422 | } | |
423 | ||
424 | /* parse arguments */ | |
425 | ret = 0; | |
426 | for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { | |
14577c39 NK |
427 | struct probe_arg *parg = &tu->tp.args[i]; |
428 | ||
f3f096cf | 429 | /* Increment count for freeing args in error case */ |
14577c39 | 430 | tu->tp.nr_args++; |
f3f096cf SD |
431 | |
432 | /* Parse argument name */ | |
433 | arg = strchr(argv[i], '='); | |
434 | if (arg) { | |
435 | *arg++ = '\0'; | |
14577c39 | 436 | parg->name = kstrdup(argv[i], GFP_KERNEL); |
f3f096cf SD |
437 | } else { |
438 | arg = argv[i]; | |
439 | /* If argument name is omitted, set "argN" */ | |
440 | snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1); | |
14577c39 | 441 | parg->name = kstrdup(buf, GFP_KERNEL); |
f3f096cf SD |
442 | } |
443 | ||
14577c39 | 444 | if (!parg->name) { |
f3f096cf SD |
445 | pr_info("Failed to allocate argument[%d] name.\n", i); |
446 | ret = -ENOMEM; | |
447 | goto error; | |
448 | } | |
449 | ||
14577c39 NK |
450 | if (!is_good_name(parg->name)) { |
451 | pr_info("Invalid argument[%d] name: %s\n", i, parg->name); | |
f3f096cf SD |
452 | ret = -EINVAL; |
453 | goto error; | |
454 | } | |
455 | ||
14577c39 | 456 | if (traceprobe_conflict_field_name(parg->name, tu->tp.args, i)) { |
f3f096cf SD |
457 | pr_info("Argument[%d] name '%s' conflicts with " |
458 | "another field.\n", i, argv[i]); | |
459 | ret = -EINVAL; | |
460 | goto error; | |
461 | } | |
462 | ||
463 | /* Parse fetch argument */ | |
14577c39 NK |
464 | ret = traceprobe_parse_probe_arg(arg, &tu->tp.size, parg, |
465 | false, false); | |
f3f096cf SD |
466 | if (ret) { |
467 | pr_info("Parse error at argument[%d]. (%d)\n", i, ret); | |
468 | goto error; | |
469 | } | |
470 | } | |
471 | ||
472 | ret = register_trace_uprobe(tu); | |
473 | if (ret) | |
474 | goto error; | |
475 | return 0; | |
476 | ||
477 | error: | |
478 | free_trace_uprobe(tu); | |
479 | return ret; | |
480 | ||
481 | fail_address_parse: | |
482 | if (inode) | |
483 | iput(inode); | |
484 | ||
d24d7dbf | 485 | pr_info("Failed to parse address or file.\n"); |
f3f096cf SD |
486 | |
487 | return ret; | |
488 | } | |
489 | ||
c6c2401d | 490 | static int cleanup_all_probes(void) |
f3f096cf SD |
491 | { |
492 | struct trace_uprobe *tu; | |
c6c2401d | 493 | int ret = 0; |
f3f096cf SD |
494 | |
495 | mutex_lock(&uprobe_lock); | |
496 | while (!list_empty(&uprobe_list)) { | |
497 | tu = list_entry(uprobe_list.next, struct trace_uprobe, list); | |
c6c2401d SRRH |
498 | ret = unregister_trace_uprobe(tu); |
499 | if (ret) | |
500 | break; | |
f3f096cf SD |
501 | } |
502 | mutex_unlock(&uprobe_lock); | |
c6c2401d | 503 | return ret; |
f3f096cf SD |
504 | } |
505 | ||
506 | /* Probes listing interfaces */ | |
507 | static void *probes_seq_start(struct seq_file *m, loff_t *pos) | |
508 | { | |
509 | mutex_lock(&uprobe_lock); | |
510 | return seq_list_start(&uprobe_list, *pos); | |
511 | } | |
512 | ||
513 | static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos) | |
514 | { | |
515 | return seq_list_next(v, &uprobe_list, pos); | |
516 | } | |
517 | ||
518 | static void probes_seq_stop(struct seq_file *m, void *v) | |
519 | { | |
520 | mutex_unlock(&uprobe_lock); | |
521 | } | |
522 | ||
523 | static int probes_seq_show(struct seq_file *m, void *v) | |
524 | { | |
525 | struct trace_uprobe *tu = v; | |
3ede82dd | 526 | char c = is_ret_probe(tu) ? 'r' : 'p'; |
f3f096cf SD |
527 | int i; |
528 | ||
14577c39 | 529 | seq_printf(m, "%c:%s/%s", c, tu->tp.call.class->system, tu->tp.call.name); |
f3f096cf SD |
530 | seq_printf(m, " %s:0x%p", tu->filename, (void *)tu->offset); |
531 | ||
14577c39 NK |
532 | for (i = 0; i < tu->tp.nr_args; i++) |
533 | seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm); | |
f3f096cf SD |
534 | |
535 | seq_printf(m, "\n"); | |
536 | return 0; | |
537 | } | |
538 | ||
539 | static const struct seq_operations probes_seq_op = { | |
540 | .start = probes_seq_start, | |
541 | .next = probes_seq_next, | |
542 | .stop = probes_seq_stop, | |
543 | .show = probes_seq_show | |
544 | }; | |
545 | ||
546 | static int probes_open(struct inode *inode, struct file *file) | |
547 | { | |
c6c2401d SRRH |
548 | int ret; |
549 | ||
550 | if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { | |
551 | ret = cleanup_all_probes(); | |
552 | if (ret) | |
553 | return ret; | |
554 | } | |
f3f096cf SD |
555 | |
556 | return seq_open(file, &probes_seq_op); | |
557 | } | |
558 | ||
559 | static ssize_t probes_write(struct file *file, const char __user *buffer, | |
560 | size_t count, loff_t *ppos) | |
561 | { | |
562 | return traceprobe_probes_write(file, buffer, count, ppos, create_trace_uprobe); | |
563 | } | |
564 | ||
565 | static const struct file_operations uprobe_events_ops = { | |
566 | .owner = THIS_MODULE, | |
567 | .open = probes_open, | |
568 | .read = seq_read, | |
569 | .llseek = seq_lseek, | |
570 | .release = seq_release, | |
571 | .write = probes_write, | |
572 | }; | |
573 | ||
574 | /* Probes profiling interfaces */ | |
575 | static int probes_profile_seq_show(struct seq_file *m, void *v) | |
576 | { | |
577 | struct trace_uprobe *tu = v; | |
578 | ||
14577c39 | 579 | seq_printf(m, " %s %-44s %15lu\n", tu->filename, tu->tp.call.name, tu->nhit); |
f3f096cf SD |
580 | return 0; |
581 | } | |
582 | ||
583 | static const struct seq_operations profile_seq_op = { | |
584 | .start = probes_seq_start, | |
585 | .next = probes_seq_next, | |
586 | .stop = probes_seq_stop, | |
587 | .show = probes_profile_seq_show | |
588 | }; | |
589 | ||
590 | static int profile_open(struct inode *inode, struct file *file) | |
591 | { | |
592 | return seq_open(file, &profile_seq_op); | |
593 | } | |
594 | ||
595 | static const struct file_operations uprobe_profile_ops = { | |
596 | .owner = THIS_MODULE, | |
597 | .open = profile_open, | |
598 | .read = seq_read, | |
599 | .llseek = seq_lseek, | |
600 | .release = seq_release, | |
601 | }; | |
602 | ||
a51cc604 ON |
603 | static void uprobe_trace_print(struct trace_uprobe *tu, |
604 | unsigned long func, struct pt_regs *regs) | |
f3f096cf SD |
605 | { |
606 | struct uprobe_trace_entry_head *entry; | |
607 | struct ring_buffer_event *event; | |
608 | struct ring_buffer *buffer; | |
457d1772 | 609 | void *data; |
0e3853d2 | 610 | int size, i; |
14577c39 | 611 | struct ftrace_event_call *call = &tu->tp.call; |
f3f096cf | 612 | |
393a736c | 613 | size = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); |
f3f096cf | 614 | event = trace_current_buffer_lock_reserve(&buffer, call->event.type, |
14577c39 | 615 | size + tu->tp.size, 0, 0); |
f3f096cf | 616 | if (!event) |
a51cc604 | 617 | return; |
f3f096cf SD |
618 | |
619 | entry = ring_buffer_event_data(event); | |
393a736c ON |
620 | if (is_ret_probe(tu)) { |
621 | entry->vaddr[0] = func; | |
622 | entry->vaddr[1] = instruction_pointer(regs); | |
623 | data = DATAOF_TRACE_ENTRY(entry, true); | |
624 | } else { | |
625 | entry->vaddr[0] = instruction_pointer(regs); | |
626 | data = DATAOF_TRACE_ENTRY(entry, false); | |
627 | } | |
628 | ||
14577c39 NK |
629 | for (i = 0; i < tu->tp.nr_args; i++) { |
630 | call_fetch(&tu->tp.args[i].fetch, regs, | |
631 | data + tu->tp.args[i].offset); | |
632 | } | |
f3f096cf | 633 | |
f306cc82 | 634 | if (!call_filter_check_discard(call, entry, buffer, event)) |
0e3853d2 | 635 | trace_buffer_unlock_commit(buffer, event, 0, 0); |
a51cc604 | 636 | } |
f42d24a1 | 637 | |
a51cc604 ON |
638 | /* uprobe handler */ |
639 | static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs) | |
640 | { | |
393a736c ON |
641 | if (!is_ret_probe(tu)) |
642 | uprobe_trace_print(tu, 0, regs); | |
f42d24a1 | 643 | return 0; |
f3f096cf SD |
644 | } |
645 | ||
c1ae5c75 ON |
646 | static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func, |
647 | struct pt_regs *regs) | |
648 | { | |
649 | uprobe_trace_print(tu, func, regs); | |
650 | } | |
651 | ||
f3f096cf SD |
652 | /* Event entry printers */ |
653 | static enum print_line_t | |
654 | print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event) | |
655 | { | |
457d1772 | 656 | struct uprobe_trace_entry_head *entry; |
f3f096cf SD |
657 | struct trace_seq *s = &iter->seq; |
658 | struct trace_uprobe *tu; | |
659 | u8 *data; | |
660 | int i; | |
661 | ||
457d1772 | 662 | entry = (struct uprobe_trace_entry_head *)iter->ent; |
14577c39 | 663 | tu = container_of(event, struct trace_uprobe, tp.call.event); |
f3f096cf | 664 | |
3ede82dd | 665 | if (is_ret_probe(tu)) { |
14577c39 | 666 | if (!trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)", tu->tp.call.name, |
3ede82dd ON |
667 | entry->vaddr[1], entry->vaddr[0])) |
668 | goto partial; | |
669 | data = DATAOF_TRACE_ENTRY(entry, true); | |
670 | } else { | |
14577c39 | 671 | if (!trace_seq_printf(s, "%s: (0x%lx)", tu->tp.call.name, |
3ede82dd ON |
672 | entry->vaddr[0])) |
673 | goto partial; | |
674 | data = DATAOF_TRACE_ENTRY(entry, false); | |
675 | } | |
f3f096cf | 676 | |
14577c39 NK |
677 | for (i = 0; i < tu->tp.nr_args; i++) { |
678 | struct probe_arg *parg = &tu->tp.args[i]; | |
679 | ||
680 | if (!parg->type->print(s, parg->name, data + parg->offset, entry)) | |
f3f096cf SD |
681 | goto partial; |
682 | } | |
683 | ||
684 | if (trace_seq_puts(s, "\n")) | |
685 | return TRACE_TYPE_HANDLED; | |
686 | ||
687 | partial: | |
688 | return TRACE_TYPE_PARTIAL_LINE; | |
689 | } | |
690 | ||
31ba3348 ON |
691 | typedef bool (*filter_func_t)(struct uprobe_consumer *self, |
692 | enum uprobe_filter_ctx ctx, | |
693 | struct mm_struct *mm); | |
694 | ||
695 | static int | |
696 | probe_event_enable(struct trace_uprobe *tu, int flag, filter_func_t filter) | |
f3f096cf | 697 | { |
f3f096cf SD |
698 | int ret = 0; |
699 | ||
14577c39 | 700 | if (trace_probe_is_enabled(&tu->tp)) |
f3f096cf SD |
701 | return -EINTR; |
702 | ||
736288ba ON |
703 | WARN_ON(!uprobe_filter_is_empty(&tu->filter)); |
704 | ||
14577c39 | 705 | tu->tp.flags |= flag; |
31ba3348 | 706 | tu->consumer.filter = filter; |
a932b738 ON |
707 | ret = uprobe_register(tu->inode, tu->offset, &tu->consumer); |
708 | if (ret) | |
14577c39 | 709 | tu->tp.flags &= ~flag; |
f3f096cf | 710 | |
4161824f | 711 | return ret; |
f3f096cf SD |
712 | } |
713 | ||
714 | static void probe_event_disable(struct trace_uprobe *tu, int flag) | |
715 | { | |
14577c39 | 716 | if (!trace_probe_is_enabled(&tu->tp)) |
f3f096cf SD |
717 | return; |
718 | ||
736288ba ON |
719 | WARN_ON(!uprobe_filter_is_empty(&tu->filter)); |
720 | ||
a932b738 | 721 | uprobe_unregister(tu->inode, tu->offset, &tu->consumer); |
14577c39 | 722 | tu->tp.flags &= ~flag; |
f3f096cf SD |
723 | } |
724 | ||
725 | static int uprobe_event_define_fields(struct ftrace_event_call *event_call) | |
726 | { | |
457d1772 | 727 | int ret, i, size; |
f3f096cf | 728 | struct uprobe_trace_entry_head field; |
457d1772 | 729 | struct trace_uprobe *tu = event_call->data; |
f3f096cf | 730 | |
4d1298e2 ON |
731 | if (is_ret_probe(tu)) { |
732 | DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0); | |
733 | DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0); | |
734 | size = SIZEOF_TRACE_ENTRY(true); | |
735 | } else { | |
736 | DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0); | |
737 | size = SIZEOF_TRACE_ENTRY(false); | |
738 | } | |
f3f096cf | 739 | /* Set argument names as fields */ |
14577c39 NK |
740 | for (i = 0; i < tu->tp.nr_args; i++) { |
741 | struct probe_arg *parg = &tu->tp.args[i]; | |
742 | ||
743 | ret = trace_define_field(event_call, parg->type->fmttype, | |
744 | parg->name, size + parg->offset, | |
745 | parg->type->size, parg->type->is_signed, | |
f3f096cf SD |
746 | FILTER_OTHER); |
747 | ||
748 | if (ret) | |
749 | return ret; | |
750 | } | |
751 | return 0; | |
752 | } | |
753 | ||
f3f096cf | 754 | #ifdef CONFIG_PERF_EVENTS |
31ba3348 ON |
755 | static bool |
756 | __uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm) | |
757 | { | |
758 | struct perf_event *event; | |
759 | ||
760 | if (filter->nr_systemwide) | |
761 | return true; | |
762 | ||
763 | list_for_each_entry(event, &filter->perf_events, hw.tp_list) { | |
764 | if (event->hw.tp_target->mm == mm) | |
765 | return true; | |
766 | } | |
767 | ||
768 | return false; | |
769 | } | |
770 | ||
b2fe8ba6 ON |
771 | static inline bool |
772 | uprobe_filter_event(struct trace_uprobe *tu, struct perf_event *event) | |
773 | { | |
774 | return __uprobe_perf_filter(&tu->filter, event->hw.tp_target->mm); | |
775 | } | |
776 | ||
736288ba ON |
777 | static int uprobe_perf_open(struct trace_uprobe *tu, struct perf_event *event) |
778 | { | |
b2fe8ba6 ON |
779 | bool done; |
780 | ||
736288ba | 781 | write_lock(&tu->filter.rwlock); |
b2fe8ba6 ON |
782 | if (event->hw.tp_target) { |
783 | /* | |
784 | * event->parent != NULL means copy_process(), we can avoid | |
785 | * uprobe_apply(). current->mm must be probed and we can rely | |
786 | * on dup_mmap() which preserves the already installed bp's. | |
787 | * | |
788 | * attr.enable_on_exec means that exec/mmap will install the | |
789 | * breakpoints we need. | |
790 | */ | |
791 | done = tu->filter.nr_systemwide || | |
792 | event->parent || event->attr.enable_on_exec || | |
793 | uprobe_filter_event(tu, event); | |
736288ba | 794 | list_add(&event->hw.tp_list, &tu->filter.perf_events); |
b2fe8ba6 ON |
795 | } else { |
796 | done = tu->filter.nr_systemwide; | |
736288ba | 797 | tu->filter.nr_systemwide++; |
b2fe8ba6 | 798 | } |
736288ba ON |
799 | write_unlock(&tu->filter.rwlock); |
800 | ||
b2fe8ba6 ON |
801 | if (!done) |
802 | uprobe_apply(tu->inode, tu->offset, &tu->consumer, true); | |
31ba3348 | 803 | |
736288ba ON |
804 | return 0; |
805 | } | |
806 | ||
807 | static int uprobe_perf_close(struct trace_uprobe *tu, struct perf_event *event) | |
808 | { | |
b2fe8ba6 ON |
809 | bool done; |
810 | ||
736288ba | 811 | write_lock(&tu->filter.rwlock); |
b2fe8ba6 | 812 | if (event->hw.tp_target) { |
736288ba | 813 | list_del(&event->hw.tp_list); |
b2fe8ba6 ON |
814 | done = tu->filter.nr_systemwide || |
815 | (event->hw.tp_target->flags & PF_EXITING) || | |
816 | uprobe_filter_event(tu, event); | |
817 | } else { | |
736288ba | 818 | tu->filter.nr_systemwide--; |
b2fe8ba6 ON |
819 | done = tu->filter.nr_systemwide; |
820 | } | |
736288ba ON |
821 | write_unlock(&tu->filter.rwlock); |
822 | ||
b2fe8ba6 ON |
823 | if (!done) |
824 | uprobe_apply(tu->inode, tu->offset, &tu->consumer, false); | |
31ba3348 | 825 | |
736288ba ON |
826 | return 0; |
827 | } | |
828 | ||
31ba3348 ON |
829 | static bool uprobe_perf_filter(struct uprobe_consumer *uc, |
830 | enum uprobe_filter_ctx ctx, struct mm_struct *mm) | |
831 | { | |
832 | struct trace_uprobe *tu; | |
833 | int ret; | |
834 | ||
835 | tu = container_of(uc, struct trace_uprobe, consumer); | |
836 | read_lock(&tu->filter.rwlock); | |
837 | ret = __uprobe_perf_filter(&tu->filter, mm); | |
838 | read_unlock(&tu->filter.rwlock); | |
839 | ||
840 | return ret; | |
841 | } | |
842 | ||
a51cc604 ON |
843 | static void uprobe_perf_print(struct trace_uprobe *tu, |
844 | unsigned long func, struct pt_regs *regs) | |
f3f096cf | 845 | { |
14577c39 | 846 | struct ftrace_event_call *call = &tu->tp.call; |
f3f096cf SD |
847 | struct uprobe_trace_entry_head *entry; |
848 | struct hlist_head *head; | |
457d1772 ON |
849 | void *data; |
850 | int size, rctx, i; | |
f3f096cf | 851 | |
393a736c | 852 | size = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); |
14577c39 | 853 | size = ALIGN(size + tu->tp.size + sizeof(u32), sizeof(u64)) - sizeof(u32); |
f3f096cf SD |
854 | |
855 | preempt_disable(); | |
515619f2 ON |
856 | head = this_cpu_ptr(call->perf_events); |
857 | if (hlist_empty(head)) | |
858 | goto out; | |
859 | ||
f3f096cf SD |
860 | entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx); |
861 | if (!entry) | |
862 | goto out; | |
863 | ||
393a736c ON |
864 | if (is_ret_probe(tu)) { |
865 | entry->vaddr[0] = func; | |
32520b2c | 866 | entry->vaddr[1] = instruction_pointer(regs); |
393a736c ON |
867 | data = DATAOF_TRACE_ENTRY(entry, true); |
868 | } else { | |
32520b2c | 869 | entry->vaddr[0] = instruction_pointer(regs); |
393a736c ON |
870 | data = DATAOF_TRACE_ENTRY(entry, false); |
871 | } | |
872 | ||
14577c39 NK |
873 | for (i = 0; i < tu->tp.nr_args; i++) { |
874 | struct probe_arg *parg = &tu->tp.args[i]; | |
875 | ||
876 | call_fetch(&parg->fetch, regs, data + parg->offset); | |
877 | } | |
f3f096cf | 878 | |
32520b2c | 879 | perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL); |
f3f096cf SD |
880 | out: |
881 | preempt_enable(); | |
a51cc604 ON |
882 | } |
883 | ||
884 | /* uprobe profile handler */ | |
885 | static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs) | |
886 | { | |
887 | if (!uprobe_perf_filter(&tu->consumer, 0, current->mm)) | |
888 | return UPROBE_HANDLER_REMOVE; | |
889 | ||
393a736c ON |
890 | if (!is_ret_probe(tu)) |
891 | uprobe_perf_print(tu, 0, regs); | |
f42d24a1 | 892 | return 0; |
f3f096cf | 893 | } |
c1ae5c75 ON |
894 | |
895 | static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func, | |
896 | struct pt_regs *regs) | |
897 | { | |
898 | uprobe_perf_print(tu, func, regs); | |
899 | } | |
f3f096cf SD |
900 | #endif /* CONFIG_PERF_EVENTS */ |
901 | ||
902 | static | |
903 | int trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type, void *data) | |
904 | { | |
457d1772 | 905 | struct trace_uprobe *tu = event->data; |
f3f096cf SD |
906 | |
907 | switch (type) { | |
908 | case TRACE_REG_REGISTER: | |
31ba3348 | 909 | return probe_event_enable(tu, TP_FLAG_TRACE, NULL); |
f3f096cf SD |
910 | |
911 | case TRACE_REG_UNREGISTER: | |
912 | probe_event_disable(tu, TP_FLAG_TRACE); | |
913 | return 0; | |
914 | ||
915 | #ifdef CONFIG_PERF_EVENTS | |
916 | case TRACE_REG_PERF_REGISTER: | |
31ba3348 | 917 | return probe_event_enable(tu, TP_FLAG_PROFILE, uprobe_perf_filter); |
f3f096cf SD |
918 | |
919 | case TRACE_REG_PERF_UNREGISTER: | |
920 | probe_event_disable(tu, TP_FLAG_PROFILE); | |
921 | return 0; | |
736288ba ON |
922 | |
923 | case TRACE_REG_PERF_OPEN: | |
924 | return uprobe_perf_open(tu, data); | |
925 | ||
926 | case TRACE_REG_PERF_CLOSE: | |
927 | return uprobe_perf_close(tu, data); | |
928 | ||
f3f096cf SD |
929 | #endif |
930 | default: | |
931 | return 0; | |
932 | } | |
933 | return 0; | |
934 | } | |
935 | ||
936 | static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs) | |
937 | { | |
f3f096cf | 938 | struct trace_uprobe *tu; |
f42d24a1 | 939 | int ret = 0; |
f3f096cf | 940 | |
a932b738 | 941 | tu = container_of(con, struct trace_uprobe, consumer); |
1b47aefd | 942 | tu->nhit++; |
f3f096cf | 943 | |
14577c39 | 944 | if (tu->tp.flags & TP_FLAG_TRACE) |
f42d24a1 | 945 | ret |= uprobe_trace_func(tu, regs); |
f3f096cf SD |
946 | |
947 | #ifdef CONFIG_PERF_EVENTS | |
14577c39 | 948 | if (tu->tp.flags & TP_FLAG_PROFILE) |
f42d24a1 | 949 | ret |= uprobe_perf_func(tu, regs); |
f3f096cf | 950 | #endif |
f42d24a1 | 951 | return ret; |
f3f096cf SD |
952 | } |
953 | ||
c1ae5c75 ON |
954 | static int uretprobe_dispatcher(struct uprobe_consumer *con, |
955 | unsigned long func, struct pt_regs *regs) | |
956 | { | |
957 | struct trace_uprobe *tu; | |
958 | ||
959 | tu = container_of(con, struct trace_uprobe, consumer); | |
960 | ||
14577c39 | 961 | if (tu->tp.flags & TP_FLAG_TRACE) |
c1ae5c75 ON |
962 | uretprobe_trace_func(tu, func, regs); |
963 | ||
964 | #ifdef CONFIG_PERF_EVENTS | |
14577c39 | 965 | if (tu->tp.flags & TP_FLAG_PROFILE) |
c1ae5c75 ON |
966 | uretprobe_perf_func(tu, func, regs); |
967 | #endif | |
968 | return 0; | |
969 | } | |
970 | ||
f3f096cf SD |
971 | static struct trace_event_functions uprobe_funcs = { |
972 | .trace = print_uprobe_event | |
973 | }; | |
974 | ||
975 | static int register_uprobe_event(struct trace_uprobe *tu) | |
976 | { | |
14577c39 | 977 | struct ftrace_event_call *call = &tu->tp.call; |
f3f096cf SD |
978 | int ret; |
979 | ||
980 | /* Initialize ftrace_event_call */ | |
981 | INIT_LIST_HEAD(&call->class->fields); | |
982 | call->event.funcs = &uprobe_funcs; | |
983 | call->class->define_fields = uprobe_event_define_fields; | |
984 | ||
5bf652aa | 985 | if (set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) |
f3f096cf SD |
986 | return -ENOMEM; |
987 | ||
988 | ret = register_ftrace_event(&call->event); | |
989 | if (!ret) { | |
990 | kfree(call->print_fmt); | |
991 | return -ENODEV; | |
992 | } | |
993 | call->flags = 0; | |
994 | call->class->reg = trace_uprobe_register; | |
995 | call->data = tu; | |
996 | ret = trace_add_event_call(call); | |
997 | ||
998 | if (ret) { | |
999 | pr_info("Failed to register uprobe event: %s\n", call->name); | |
1000 | kfree(call->print_fmt); | |
1001 | unregister_ftrace_event(&call->event); | |
1002 | } | |
1003 | ||
1004 | return ret; | |
1005 | } | |
1006 | ||
c6c2401d | 1007 | static int unregister_uprobe_event(struct trace_uprobe *tu) |
f3f096cf | 1008 | { |
c6c2401d SRRH |
1009 | int ret; |
1010 | ||
f3f096cf | 1011 | /* tu->event is unregistered in trace_remove_event_call() */ |
14577c39 | 1012 | ret = trace_remove_event_call(&tu->tp.call); |
c6c2401d SRRH |
1013 | if (ret) |
1014 | return ret; | |
14577c39 NK |
1015 | kfree(tu->tp.call.print_fmt); |
1016 | tu->tp.call.print_fmt = NULL; | |
c6c2401d | 1017 | return 0; |
f3f096cf SD |
1018 | } |
1019 | ||
1020 | /* Make a trace interface for controling probe points */ | |
1021 | static __init int init_uprobe_trace(void) | |
1022 | { | |
1023 | struct dentry *d_tracer; | |
1024 | ||
1025 | d_tracer = tracing_init_dentry(); | |
1026 | if (!d_tracer) | |
1027 | return 0; | |
1028 | ||
1029 | trace_create_file("uprobe_events", 0644, d_tracer, | |
1030 | NULL, &uprobe_events_ops); | |
1031 | /* Profile interface */ | |
1032 | trace_create_file("uprobe_profile", 0444, d_tracer, | |
1033 | NULL, &uprobe_profile_ops); | |
1034 | return 0; | |
1035 | } | |
1036 | ||
1037 | fs_initcall(init_uprobe_trace); |