Commit | Line | Data |
---|---|---|
7f5a08c7 BB |
1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* | |
3 | * Copyright (c) 2021, Microsoft Corporation. | |
4 | * | |
5 | * Authors: | |
6 | * Beau Belgrave <beaub@linux.microsoft.com> | |
7 | */ | |
8 | ||
9 | #include <linux/bitmap.h> | |
10 | #include <linux/cdev.h> | |
11 | #include <linux/hashtable.h> | |
12 | #include <linux/list.h> | |
13 | #include <linux/io.h> | |
14 | #include <linux/uio.h> | |
15 | #include <linux/ioctl.h> | |
16 | #include <linux/jhash.h> | |
d401b724 | 17 | #include <linux/refcount.h> |
7f5a08c7 BB |
18 | #include <linux/trace_events.h> |
19 | #include <linux/tracefs.h> | |
20 | #include <linux/types.h> | |
21 | #include <linux/uaccess.h> | |
5cfff569 SRG |
22 | /* Reminder to move to uapi when everything works */ |
23 | #ifdef CONFIG_COMPILE_TEST | |
24 | #include <linux/user_events.h> | |
25 | #else | |
7f5a08c7 | 26 | #include <uapi/linux/user_events.h> |
5cfff569 | 27 | #endif |
7f5a08c7 BB |
28 | #include "trace.h" |
29 | #include "trace_dynevent.h" | |
30 | ||
31 | #define USER_EVENTS_PREFIX_LEN (sizeof(USER_EVENTS_PREFIX)-1) | |
32 | ||
33 | #define FIELD_DEPTH_TYPE 0 | |
34 | #define FIELD_DEPTH_NAME 1 | |
35 | #define FIELD_DEPTH_SIZE 2 | |
36 | ||
37 | /* | |
38 | * Limits how many trace_event calls user processes can create: | |
bc47ee48 | 39 | * Must be a power of two of PAGE_SIZE. |
7f5a08c7 | 40 | */ |
bc47ee48 SRG |
41 | #define MAX_PAGE_ORDER 0 |
42 | #define MAX_PAGES (1 << MAX_PAGE_ORDER) | |
39d6d08b BB |
43 | #define MAX_BYTES (MAX_PAGES * PAGE_SIZE) |
44 | #define MAX_EVENTS (MAX_BYTES * 8) | |
7f5a08c7 BB |
45 | |
46 | /* Limit how long of an event name plus args within the subsystem. */ | |
47 | #define MAX_EVENT_DESC 512 | |
48 | #define EVENT_NAME(user_event) ((user_event)->tracepoint.name) | |
49 | #define MAX_FIELD_ARRAY_SIZE 1024 | |
50 | ||
39d6d08b BB |
51 | /* |
52 | * The MAP_STATUS_* macros are used for taking a index and determining the | |
53 | * appropriate byte and the bit in the byte to set/reset for an event. | |
54 | * | |
55 | * The lower 3 bits of the index decide which bit to set. | |
56 | * The remaining upper bits of the index decide which byte to use for the bit. | |
57 | * | |
58 | * This is used when an event has a probe attached/removed to reflect live | |
59 | * status of the event wanting tracing or not to user-programs via shared | |
60 | * memory maps. | |
61 | */ | |
62 | #define MAP_STATUS_BYTE(index) ((index) >> 3) | |
63 | #define MAP_STATUS_MASK(index) BIT((index) & 7) | |
64 | ||
65 | /* | |
66 | * Internal bits (kernel side only) to keep track of connected probes: | |
67 | * These are used when status is requested in text form about an event. These | |
68 | * bits are compared against an internal byte on the event to determine which | |
69 | * probes to print out to the user. | |
70 | * | |
71 | * These do not reflect the mapped bytes between the user and kernel space. | |
72 | */ | |
73 | #define EVENT_STATUS_FTRACE BIT(0) | |
74 | #define EVENT_STATUS_PERF BIT(1) | |
75 | #define EVENT_STATUS_OTHER BIT(7) | |
76 | ||
e5d27181 BB |
77 | /* |
78 | * Stores the pages, tables, and locks for a group of events. | |
79 | * Each logical grouping of events has its own group, with a | |
80 | * matching page for status checks within user programs. This | |
81 | * allows for isolation of events to user programs by various | |
82 | * means. | |
83 | */ | |
84 | struct user_event_group { | |
85 | struct page *pages; | |
86 | char *register_page_data; | |
87 | char *system_name; | |
88 | struct hlist_node node; | |
89 | struct mutex reg_mutex; | |
90 | DECLARE_HASHTABLE(register_table, 8); | |
91 | DECLARE_BITMAP(page_bitmap, MAX_EVENTS); | |
92 | }; | |
7f5a08c7 | 93 | |
e5d27181 BB |
94 | /* Group for init_user_ns mapping, top-most group */ |
95 | static struct user_event_group *init_group; | |
7f5a08c7 BB |
96 | |
97 | /* | |
98 | * Stores per-event properties, as users register events | |
99 | * within a file a user_event might be created if it does not | |
100 | * already exist. These are globally used and their lifetime | |
101 | * is tied to the refcnt member. These cannot go away until the | |
d401b724 | 102 | * refcnt reaches one. |
7f5a08c7 BB |
103 | */ |
104 | struct user_event { | |
e5d27181 | 105 | struct user_event_group *group; |
7f5a08c7 BB |
106 | struct tracepoint tracepoint; |
107 | struct trace_event_call call; | |
108 | struct trace_event_class class; | |
109 | struct dyn_event devent; | |
110 | struct hlist_node node; | |
111 | struct list_head fields; | |
2467cda1 | 112 | struct list_head validators; |
d401b724 | 113 | refcount_t refcnt; |
7f5a08c7 BB |
114 | int index; |
115 | int flags; | |
2467cda1 | 116 | int min_size; |
39d6d08b | 117 | char status; |
7f5a08c7 BB |
118 | }; |
119 | ||
120 | /* | |
121 | * Stores per-file events references, as users register events | |
122 | * within a file this structure is modified and freed via RCU. | |
123 | * The lifetime of this struct is tied to the lifetime of the file. | |
124 | * These are not shared and only accessible by the file that created it. | |
125 | */ | |
126 | struct user_event_refs { | |
127 | struct rcu_head rcu; | |
128 | int count; | |
129 | struct user_event *events[]; | |
130 | }; | |
131 | ||
e5d27181 BB |
132 | struct user_event_file_info { |
133 | struct user_event_group *group; | |
134 | struct user_event_refs *refs; | |
135 | }; | |
136 | ||
2467cda1 BB |
137 | #define VALIDATOR_ENSURE_NULL (1 << 0) |
138 | #define VALIDATOR_REL (1 << 1) | |
139 | ||
140 | struct user_event_validator { | |
141 | struct list_head link; | |
142 | int offset; | |
143 | int flags; | |
144 | }; | |
145 | ||
0279400a | 146 | typedef void (*user_event_func_t) (struct user_event *user, struct iov_iter *i, |
2467cda1 | 147 | void *tpdata, bool *faulted); |
7f5a08c7 | 148 | |
e5d27181 BB |
149 | static int user_event_parse(struct user_event_group *group, char *name, |
150 | char *args, char *flags, | |
7f5a08c7 BB |
151 | struct user_event **newuser); |
152 | ||
153 | static u32 user_event_key(char *name) | |
154 | { | |
155 | return jhash(name, strlen(name), 0); | |
156 | } | |
157 | ||
e5d27181 BB |
158 | static void set_page_reservations(char *pages, bool set) |
159 | { | |
160 | int page; | |
161 | ||
162 | for (page = 0; page < MAX_PAGES; ++page) { | |
163 | void *addr = pages + (PAGE_SIZE * page); | |
164 | ||
165 | if (set) | |
166 | SetPageReserved(virt_to_page(addr)); | |
167 | else | |
168 | ClearPageReserved(virt_to_page(addr)); | |
169 | } | |
170 | } | |
171 | ||
172 | static void user_event_group_destroy(struct user_event_group *group) | |
173 | { | |
174 | if (group->register_page_data) | |
175 | set_page_reservations(group->register_page_data, false); | |
176 | ||
177 | if (group->pages) | |
178 | __free_pages(group->pages, MAX_PAGE_ORDER); | |
179 | ||
180 | kfree(group->system_name); | |
181 | kfree(group); | |
182 | } | |
183 | ||
184 | static char *user_event_group_system_name(struct user_namespace *user_ns) | |
185 | { | |
186 | char *system_name; | |
187 | int len = sizeof(USER_EVENTS_SYSTEM) + 1; | |
188 | ||
189 | if (user_ns != &init_user_ns) { | |
190 | /* | |
191 | * Unexpected at this point: | |
192 | * We only currently support init_user_ns. | |
193 | * When we enable more, this will trigger a failure so log. | |
194 | */ | |
195 | pr_warn("user_events: Namespace other than init_user_ns!\n"); | |
196 | return NULL; | |
197 | } | |
198 | ||
199 | system_name = kmalloc(len, GFP_KERNEL); | |
200 | ||
201 | if (!system_name) | |
202 | return NULL; | |
203 | ||
204 | snprintf(system_name, len, "%s", USER_EVENTS_SYSTEM); | |
205 | ||
206 | return system_name; | |
207 | } | |
208 | ||
209 | static inline struct user_event_group | |
210 | *user_event_group_from_user_ns(struct user_namespace *user_ns) | |
211 | { | |
212 | if (user_ns == &init_user_ns) | |
213 | return init_group; | |
214 | ||
215 | return NULL; | |
216 | } | |
217 | ||
218 | static struct user_event_group *current_user_event_group(void) | |
219 | { | |
220 | struct user_namespace *user_ns = current_user_ns(); | |
221 | struct user_event_group *group = NULL; | |
222 | ||
223 | while (user_ns) { | |
224 | group = user_event_group_from_user_ns(user_ns); | |
225 | ||
226 | if (group) | |
227 | break; | |
228 | ||
229 | user_ns = user_ns->parent; | |
230 | } | |
231 | ||
232 | return group; | |
233 | } | |
234 | ||
235 | static struct user_event_group | |
236 | *user_event_group_create(struct user_namespace *user_ns) | |
237 | { | |
238 | struct user_event_group *group; | |
239 | ||
240 | group = kzalloc(sizeof(*group), GFP_KERNEL); | |
241 | ||
242 | if (!group) | |
243 | return NULL; | |
244 | ||
245 | group->system_name = user_event_group_system_name(user_ns); | |
246 | ||
247 | if (!group->system_name) | |
248 | goto error; | |
249 | ||
250 | group->pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, MAX_PAGE_ORDER); | |
251 | ||
252 | if (!group->pages) | |
253 | goto error; | |
254 | ||
255 | group->register_page_data = page_address(group->pages); | |
256 | ||
257 | set_page_reservations(group->register_page_data, true); | |
258 | ||
259 | /* Zero all bits beside 0 (which is reserved for failures) */ | |
260 | bitmap_zero(group->page_bitmap, MAX_EVENTS); | |
261 | set_bit(0, group->page_bitmap); | |
262 | ||
263 | mutex_init(&group->reg_mutex); | |
264 | hash_init(group->register_table); | |
265 | ||
266 | return group; | |
267 | error: | |
268 | if (group) | |
269 | user_event_group_destroy(group); | |
270 | ||
271 | return NULL; | |
272 | }; | |
273 | ||
39d6d08b BB |
274 | static __always_inline |
275 | void user_event_register_set(struct user_event *user) | |
276 | { | |
277 | int i = user->index; | |
278 | ||
e5d27181 | 279 | user->group->register_page_data[MAP_STATUS_BYTE(i)] |= MAP_STATUS_MASK(i); |
39d6d08b BB |
280 | } |
281 | ||
282 | static __always_inline | |
283 | void user_event_register_clear(struct user_event *user) | |
284 | { | |
285 | int i = user->index; | |
286 | ||
e5d27181 | 287 | user->group->register_page_data[MAP_STATUS_BYTE(i)] &= ~MAP_STATUS_MASK(i); |
39d6d08b BB |
288 | } |
289 | ||
d401b724 BB |
290 | static __always_inline __must_check |
291 | bool user_event_last_ref(struct user_event *user) | |
292 | { | |
293 | return refcount_read(&user->refcnt) == 1; | |
294 | } | |
295 | ||
0279400a BB |
296 | static __always_inline __must_check |
297 | size_t copy_nofault(void *addr, size_t bytes, struct iov_iter *i) | |
298 | { | |
299 | size_t ret; | |
300 | ||
301 | pagefault_disable(); | |
302 | ||
303 | ret = copy_from_iter_nocache(addr, bytes, i); | |
304 | ||
305 | pagefault_enable(); | |
306 | ||
307 | return ret; | |
308 | } | |
309 | ||
7f5a08c7 BB |
310 | static struct list_head *user_event_get_fields(struct trace_event_call *call) |
311 | { | |
312 | struct user_event *user = (struct user_event *)call->data; | |
313 | ||
314 | return &user->fields; | |
315 | } | |
316 | ||
317 | /* | |
318 | * Parses a register command for user_events | |
319 | * Format: event_name[:FLAG1[,FLAG2...]] [field1[;field2...]] | |
320 | * | |
321 | * Example event named 'test' with a 20 char 'msg' field with an unsigned int | |
322 | * 'id' field after: | |
323 | * test char[20] msg;unsigned int id | |
324 | * | |
325 | * NOTE: Offsets are from the user data perspective, they are not from the | |
326 | * trace_entry/buffer perspective. We automatically add the common properties | |
327 | * sizes to the offset for the user. | |
7e348b32 BB |
328 | * |
329 | * Upon success user_event has its ref count increased by 1. | |
7f5a08c7 | 330 | */ |
e5d27181 BB |
331 | static int user_event_parse_cmd(struct user_event_group *group, |
332 | char *raw_command, struct user_event **newuser) | |
7f5a08c7 BB |
333 | { |
334 | char *name = raw_command; | |
335 | char *args = strpbrk(name, " "); | |
336 | char *flags; | |
337 | ||
338 | if (args) | |
339 | *args++ = '\0'; | |
340 | ||
341 | flags = strpbrk(name, ":"); | |
342 | ||
343 | if (flags) | |
344 | *flags++ = '\0'; | |
345 | ||
e5d27181 | 346 | return user_event_parse(group, name, args, flags, newuser); |
7f5a08c7 BB |
347 | } |
348 | ||
349 | static int user_field_array_size(const char *type) | |
350 | { | |
351 | const char *start = strchr(type, '['); | |
352 | char val[8]; | |
353 | char *bracket; | |
354 | int size = 0; | |
355 | ||
356 | if (start == NULL) | |
357 | return -EINVAL; | |
358 | ||
359 | if (strscpy(val, start + 1, sizeof(val)) <= 0) | |
360 | return -EINVAL; | |
361 | ||
362 | bracket = strchr(val, ']'); | |
363 | ||
364 | if (!bracket) | |
365 | return -EINVAL; | |
366 | ||
367 | *bracket = '\0'; | |
368 | ||
369 | if (kstrtouint(val, 0, &size)) | |
370 | return -EINVAL; | |
371 | ||
372 | if (size > MAX_FIELD_ARRAY_SIZE) | |
373 | return -EINVAL; | |
374 | ||
375 | return size; | |
376 | } | |
377 | ||
378 | static int user_field_size(const char *type) | |
379 | { | |
380 | /* long is not allowed from a user, since it's ambigious in size */ | |
381 | if (strcmp(type, "s64") == 0) | |
382 | return sizeof(s64); | |
383 | if (strcmp(type, "u64") == 0) | |
384 | return sizeof(u64); | |
385 | if (strcmp(type, "s32") == 0) | |
386 | return sizeof(s32); | |
387 | if (strcmp(type, "u32") == 0) | |
388 | return sizeof(u32); | |
389 | if (strcmp(type, "int") == 0) | |
390 | return sizeof(int); | |
391 | if (strcmp(type, "unsigned int") == 0) | |
392 | return sizeof(unsigned int); | |
393 | if (strcmp(type, "s16") == 0) | |
394 | return sizeof(s16); | |
395 | if (strcmp(type, "u16") == 0) | |
396 | return sizeof(u16); | |
397 | if (strcmp(type, "short") == 0) | |
398 | return sizeof(short); | |
399 | if (strcmp(type, "unsigned short") == 0) | |
400 | return sizeof(unsigned short); | |
401 | if (strcmp(type, "s8") == 0) | |
402 | return sizeof(s8); | |
403 | if (strcmp(type, "u8") == 0) | |
404 | return sizeof(u8); | |
405 | if (strcmp(type, "char") == 0) | |
406 | return sizeof(char); | |
407 | if (strcmp(type, "unsigned char") == 0) | |
408 | return sizeof(unsigned char); | |
409 | if (str_has_prefix(type, "char[")) | |
410 | return user_field_array_size(type); | |
411 | if (str_has_prefix(type, "unsigned char[")) | |
412 | return user_field_array_size(type); | |
413 | if (str_has_prefix(type, "__data_loc ")) | |
414 | return sizeof(u32); | |
415 | if (str_has_prefix(type, "__rel_loc ")) | |
416 | return sizeof(u32); | |
417 | ||
418 | /* Uknown basic type, error */ | |
419 | return -EINVAL; | |
420 | } | |
421 | ||
2467cda1 BB |
422 | static void user_event_destroy_validators(struct user_event *user) |
423 | { | |
424 | struct user_event_validator *validator, *next; | |
425 | struct list_head *head = &user->validators; | |
426 | ||
427 | list_for_each_entry_safe(validator, next, head, link) { | |
428 | list_del(&validator->link); | |
429 | kfree(validator); | |
430 | } | |
431 | } | |
432 | ||
7f5a08c7 BB |
433 | static void user_event_destroy_fields(struct user_event *user) |
434 | { | |
435 | struct ftrace_event_field *field, *next; | |
436 | struct list_head *head = &user->fields; | |
437 | ||
438 | list_for_each_entry_safe(field, next, head, link) { | |
439 | list_del(&field->link); | |
440 | kfree(field); | |
441 | } | |
442 | } | |
443 | ||
444 | static int user_event_add_field(struct user_event *user, const char *type, | |
445 | const char *name, int offset, int size, | |
446 | int is_signed, int filter_type) | |
447 | { | |
2467cda1 | 448 | struct user_event_validator *validator; |
7f5a08c7 | 449 | struct ftrace_event_field *field; |
2467cda1 | 450 | int validator_flags = 0; |
7f5a08c7 BB |
451 | |
452 | field = kmalloc(sizeof(*field), GFP_KERNEL); | |
453 | ||
454 | if (!field) | |
455 | return -ENOMEM; | |
456 | ||
2467cda1 BB |
457 | if (str_has_prefix(type, "__data_loc ")) |
458 | goto add_validator; | |
459 | ||
460 | if (str_has_prefix(type, "__rel_loc ")) { | |
461 | validator_flags |= VALIDATOR_REL; | |
462 | goto add_validator; | |
463 | } | |
464 | ||
465 | goto add_field; | |
466 | ||
467 | add_validator: | |
9cbf1234 | 468 | if (strstr(type, "char") != NULL) |
2467cda1 BB |
469 | validator_flags |= VALIDATOR_ENSURE_NULL; |
470 | ||
471 | validator = kmalloc(sizeof(*validator), GFP_KERNEL); | |
472 | ||
473 | if (!validator) { | |
474 | kfree(field); | |
475 | return -ENOMEM; | |
476 | } | |
477 | ||
478 | validator->flags = validator_flags; | |
479 | validator->offset = offset; | |
480 | ||
481 | /* Want sequential access when validating */ | |
482 | list_add_tail(&validator->link, &user->validators); | |
483 | ||
484 | add_field: | |
7f5a08c7 BB |
485 | field->type = type; |
486 | field->name = name; | |
487 | field->offset = offset; | |
488 | field->size = size; | |
489 | field->is_signed = is_signed; | |
490 | field->filter_type = filter_type; | |
491 | ||
492 | list_add(&field->link, &user->fields); | |
493 | ||
2467cda1 BB |
494 | /* |
495 | * Min size from user writes that are required, this does not include | |
496 | * the size of trace_entry (common fields). | |
497 | */ | |
498 | user->min_size = (offset + size) - sizeof(struct trace_entry); | |
499 | ||
7f5a08c7 BB |
500 | return 0; |
501 | } | |
502 | ||
503 | /* | |
504 | * Parses the values of a field within the description | |
505 | * Format: type name [size] | |
506 | */ | |
507 | static int user_event_parse_field(char *field, struct user_event *user, | |
508 | u32 *offset) | |
509 | { | |
510 | char *part, *type, *name; | |
511 | u32 depth = 0, saved_offset = *offset; | |
512 | int len, size = -EINVAL; | |
513 | bool is_struct = false; | |
514 | ||
515 | field = skip_spaces(field); | |
516 | ||
517 | if (*field == '\0') | |
518 | return 0; | |
519 | ||
520 | /* Handle types that have a space within */ | |
521 | len = str_has_prefix(field, "unsigned "); | |
522 | if (len) | |
523 | goto skip_next; | |
524 | ||
525 | len = str_has_prefix(field, "struct "); | |
526 | if (len) { | |
527 | is_struct = true; | |
528 | goto skip_next; | |
529 | } | |
530 | ||
531 | len = str_has_prefix(field, "__data_loc unsigned "); | |
532 | if (len) | |
533 | goto skip_next; | |
534 | ||
535 | len = str_has_prefix(field, "__data_loc "); | |
536 | if (len) | |
537 | goto skip_next; | |
538 | ||
539 | len = str_has_prefix(field, "__rel_loc unsigned "); | |
540 | if (len) | |
541 | goto skip_next; | |
542 | ||
543 | len = str_has_prefix(field, "__rel_loc "); | |
544 | if (len) | |
545 | goto skip_next; | |
546 | ||
547 | goto parse; | |
548 | skip_next: | |
549 | type = field; | |
550 | field = strpbrk(field + len, " "); | |
551 | ||
552 | if (field == NULL) | |
553 | return -EINVAL; | |
554 | ||
555 | *field++ = '\0'; | |
556 | depth++; | |
557 | parse: | |
173c2049 BB |
558 | name = NULL; |
559 | ||
7f5a08c7 BB |
560 | while ((part = strsep(&field, " ")) != NULL) { |
561 | switch (depth++) { | |
562 | case FIELD_DEPTH_TYPE: | |
563 | type = part; | |
564 | break; | |
565 | case FIELD_DEPTH_NAME: | |
566 | name = part; | |
567 | break; | |
568 | case FIELD_DEPTH_SIZE: | |
569 | if (!is_struct) | |
570 | return -EINVAL; | |
571 | ||
572 | if (kstrtou32(part, 10, &size)) | |
573 | return -EINVAL; | |
574 | break; | |
575 | default: | |
576 | return -EINVAL; | |
577 | } | |
578 | } | |
579 | ||
173c2049 | 580 | if (depth < FIELD_DEPTH_SIZE || !name) |
7f5a08c7 BB |
581 | return -EINVAL; |
582 | ||
583 | if (depth == FIELD_DEPTH_SIZE) | |
584 | size = user_field_size(type); | |
585 | ||
586 | if (size == 0) | |
587 | return -EINVAL; | |
588 | ||
589 | if (size < 0) | |
590 | return size; | |
591 | ||
592 | *offset = saved_offset + size; | |
593 | ||
594 | return user_event_add_field(user, type, name, saved_offset, size, | |
595 | type[0] != 'u', FILTER_OTHER); | |
596 | } | |
597 | ||
7f5a08c7 BB |
598 | static int user_event_parse_fields(struct user_event *user, char *args) |
599 | { | |
600 | char *field; | |
601 | u32 offset = sizeof(struct trace_entry); | |
602 | int ret = -EINVAL; | |
603 | ||
604 | if (args == NULL) | |
605 | return 0; | |
606 | ||
607 | while ((field = strsep(&args, ";")) != NULL) { | |
608 | ret = user_event_parse_field(field, user, &offset); | |
609 | ||
610 | if (ret) | |
611 | break; | |
612 | } | |
613 | ||
614 | return ret; | |
615 | } | |
616 | ||
617 | static struct trace_event_fields user_event_fields_array[1]; | |
618 | ||
aa3b2b4c BB |
619 | static const char *user_field_format(const char *type) |
620 | { | |
621 | if (strcmp(type, "s64") == 0) | |
622 | return "%lld"; | |
623 | if (strcmp(type, "u64") == 0) | |
624 | return "%llu"; | |
625 | if (strcmp(type, "s32") == 0) | |
626 | return "%d"; | |
627 | if (strcmp(type, "u32") == 0) | |
628 | return "%u"; | |
629 | if (strcmp(type, "int") == 0) | |
630 | return "%d"; | |
631 | if (strcmp(type, "unsigned int") == 0) | |
632 | return "%u"; | |
633 | if (strcmp(type, "s16") == 0) | |
634 | return "%d"; | |
635 | if (strcmp(type, "u16") == 0) | |
636 | return "%u"; | |
637 | if (strcmp(type, "short") == 0) | |
638 | return "%d"; | |
639 | if (strcmp(type, "unsigned short") == 0) | |
640 | return "%u"; | |
641 | if (strcmp(type, "s8") == 0) | |
642 | return "%d"; | |
643 | if (strcmp(type, "u8") == 0) | |
644 | return "%u"; | |
645 | if (strcmp(type, "char") == 0) | |
646 | return "%d"; | |
647 | if (strcmp(type, "unsigned char") == 0) | |
648 | return "%u"; | |
9cbf1234 | 649 | if (strstr(type, "char[") != NULL) |
aa3b2b4c BB |
650 | return "%s"; |
651 | ||
652 | /* Unknown, likely struct, allowed treat as 64-bit */ | |
653 | return "%llu"; | |
654 | } | |
655 | ||
656 | static bool user_field_is_dyn_string(const char *type, const char **str_func) | |
657 | { | |
658 | if (str_has_prefix(type, "__data_loc ")) { | |
659 | *str_func = "__get_str"; | |
660 | goto check; | |
661 | } | |
662 | ||
663 | if (str_has_prefix(type, "__rel_loc ")) { | |
664 | *str_func = "__get_rel_str"; | |
665 | goto check; | |
666 | } | |
667 | ||
668 | return false; | |
669 | check: | |
9cbf1234 | 670 | return strstr(type, "char") != NULL; |
aa3b2b4c BB |
671 | } |
672 | ||
673 | #define LEN_OR_ZERO (len ? len - pos : 0) | |
e6f89a14 BB |
674 | static int user_dyn_field_set_string(int argc, const char **argv, int *iout, |
675 | char *buf, int len, bool *colon) | |
676 | { | |
677 | int pos = 0, i = *iout; | |
678 | ||
679 | *colon = false; | |
680 | ||
681 | for (; i < argc; ++i) { | |
682 | if (i != *iout) | |
683 | pos += snprintf(buf + pos, LEN_OR_ZERO, " "); | |
684 | ||
685 | pos += snprintf(buf + pos, LEN_OR_ZERO, "%s", argv[i]); | |
686 | ||
687 | if (strchr(argv[i], ';')) { | |
688 | ++i; | |
689 | *colon = true; | |
690 | break; | |
691 | } | |
692 | } | |
693 | ||
694 | /* Actual set, advance i */ | |
695 | if (len != 0) | |
696 | *iout = i; | |
697 | ||
698 | return pos + 1; | |
699 | } | |
700 | ||
701 | static int user_field_set_string(struct ftrace_event_field *field, | |
702 | char *buf, int len, bool colon) | |
703 | { | |
704 | int pos = 0; | |
705 | ||
706 | pos += snprintf(buf + pos, LEN_OR_ZERO, "%s", field->type); | |
707 | pos += snprintf(buf + pos, LEN_OR_ZERO, " "); | |
708 | pos += snprintf(buf + pos, LEN_OR_ZERO, "%s", field->name); | |
709 | ||
710 | if (colon) | |
711 | pos += snprintf(buf + pos, LEN_OR_ZERO, ";"); | |
712 | ||
713 | return pos + 1; | |
714 | } | |
715 | ||
aa3b2b4c BB |
716 | static int user_event_set_print_fmt(struct user_event *user, char *buf, int len) |
717 | { | |
718 | struct ftrace_event_field *field, *next; | |
719 | struct list_head *head = &user->fields; | |
720 | int pos = 0, depth = 0; | |
721 | const char *str_func; | |
722 | ||
723 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); | |
724 | ||
725 | list_for_each_entry_safe_reverse(field, next, head, link) { | |
726 | if (depth != 0) | |
727 | pos += snprintf(buf + pos, LEN_OR_ZERO, " "); | |
728 | ||
729 | pos += snprintf(buf + pos, LEN_OR_ZERO, "%s=%s", | |
730 | field->name, user_field_format(field->type)); | |
731 | ||
732 | depth++; | |
733 | } | |
734 | ||
735 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); | |
736 | ||
737 | list_for_each_entry_safe_reverse(field, next, head, link) { | |
738 | if (user_field_is_dyn_string(field->type, &str_func)) | |
739 | pos += snprintf(buf + pos, LEN_OR_ZERO, | |
740 | ", %s(%s)", str_func, field->name); | |
741 | else | |
742 | pos += snprintf(buf + pos, LEN_OR_ZERO, | |
743 | ", REC->%s", field->name); | |
744 | } | |
745 | ||
746 | return pos + 1; | |
747 | } | |
748 | #undef LEN_OR_ZERO | |
749 | ||
750 | static int user_event_create_print_fmt(struct user_event *user) | |
751 | { | |
752 | char *print_fmt; | |
753 | int len; | |
754 | ||
755 | len = user_event_set_print_fmt(user, NULL, 0); | |
756 | ||
757 | print_fmt = kmalloc(len, GFP_KERNEL); | |
758 | ||
759 | if (!print_fmt) | |
760 | return -ENOMEM; | |
761 | ||
762 | user_event_set_print_fmt(user, print_fmt, len); | |
763 | ||
764 | user->call.print_fmt = print_fmt; | |
765 | ||
766 | return 0; | |
767 | } | |
768 | ||
7f5a08c7 BB |
769 | static enum print_line_t user_event_print_trace(struct trace_iterator *iter, |
770 | int flags, | |
771 | struct trace_event *event) | |
772 | { | |
773 | /* Unsafe to try to decode user provided print_fmt, use hex */ | |
774 | trace_print_hex_dump_seq(&iter->seq, "", DUMP_PREFIX_OFFSET, 16, | |
775 | 1, iter->ent, iter->ent_size, true); | |
776 | ||
777 | return trace_handle_return(&iter->seq); | |
778 | } | |
779 | ||
780 | static struct trace_event_functions user_event_funcs = { | |
781 | .trace = user_event_print_trace, | |
782 | }; | |
783 | ||
089331d4 BB |
784 | static int user_event_set_call_visible(struct user_event *user, bool visible) |
785 | { | |
786 | int ret; | |
787 | const struct cred *old_cred; | |
788 | struct cred *cred; | |
789 | ||
790 | cred = prepare_creds(); | |
791 | ||
792 | if (!cred) | |
793 | return -ENOMEM; | |
794 | ||
795 | /* | |
796 | * While by default tracefs is locked down, systems can be configured | |
797 | * to allow user_event files to be less locked down. The extreme case | |
798 | * being "other" has read/write access to user_events_data/status. | |
799 | * | |
94c255ac | 800 | * When not locked down, processes may not have permissions to |
089331d4 BB |
801 | * add/remove calls themselves to tracefs. We need to temporarily |
802 | * switch to root file permission to allow for this scenario. | |
803 | */ | |
804 | cred->fsuid = GLOBAL_ROOT_UID; | |
805 | ||
806 | old_cred = override_creds(cred); | |
807 | ||
808 | if (visible) | |
809 | ret = trace_add_event_call(&user->call); | |
810 | else | |
811 | ret = trace_remove_event_call(&user->call); | |
812 | ||
813 | revert_creds(old_cred); | |
814 | put_cred(cred); | |
815 | ||
816 | return ret; | |
817 | } | |
818 | ||
7f5a08c7 BB |
819 | static int destroy_user_event(struct user_event *user) |
820 | { | |
821 | int ret = 0; | |
822 | ||
823 | /* Must destroy fields before call removal */ | |
824 | user_event_destroy_fields(user); | |
825 | ||
089331d4 | 826 | ret = user_event_set_call_visible(user, false); |
7f5a08c7 BB |
827 | |
828 | if (ret) | |
829 | return ret; | |
830 | ||
831 | dyn_event_remove(&user->devent); | |
832 | ||
39d6d08b | 833 | user_event_register_clear(user); |
e5d27181 | 834 | clear_bit(user->index, user->group->page_bitmap); |
7f5a08c7 BB |
835 | hash_del(&user->node); |
836 | ||
2467cda1 | 837 | user_event_destroy_validators(user); |
aa3b2b4c | 838 | kfree(user->call.print_fmt); |
7f5a08c7 BB |
839 | kfree(EVENT_NAME(user)); |
840 | kfree(user); | |
841 | ||
842 | return ret; | |
843 | } | |
844 | ||
e5d27181 BB |
845 | static struct user_event *find_user_event(struct user_event_group *group, |
846 | char *name, u32 *outkey) | |
7f5a08c7 BB |
847 | { |
848 | struct user_event *user; | |
849 | u32 key = user_event_key(name); | |
850 | ||
851 | *outkey = key; | |
852 | ||
e5d27181 | 853 | hash_for_each_possible(group->register_table, user, node, key) |
7e348b32 | 854 | if (!strcmp(EVENT_NAME(user), name)) { |
d401b724 | 855 | refcount_inc(&user->refcnt); |
7f5a08c7 | 856 | return user; |
7e348b32 | 857 | } |
7f5a08c7 BB |
858 | |
859 | return NULL; | |
860 | } | |
861 | ||
2467cda1 BB |
862 | static int user_event_validate(struct user_event *user, void *data, int len) |
863 | { | |
864 | struct list_head *head = &user->validators; | |
865 | struct user_event_validator *validator; | |
866 | void *pos, *end = data + len; | |
867 | u32 loc, offset, size; | |
868 | ||
869 | list_for_each_entry(validator, head, link) { | |
870 | pos = data + validator->offset; | |
871 | ||
872 | /* Already done min_size check, no bounds check here */ | |
873 | loc = *(u32 *)pos; | |
874 | offset = loc & 0xffff; | |
875 | size = loc >> 16; | |
876 | ||
877 | if (likely(validator->flags & VALIDATOR_REL)) | |
878 | pos += offset + sizeof(loc); | |
879 | else | |
880 | pos = data + offset; | |
881 | ||
882 | pos += size; | |
883 | ||
884 | if (unlikely(pos > end)) | |
885 | return -EFAULT; | |
886 | ||
887 | if (likely(validator->flags & VALIDATOR_ENSURE_NULL)) | |
888 | if (unlikely(*(char *)(pos - 1) != '\0')) | |
889 | return -EFAULT; | |
890 | } | |
891 | ||
892 | return 0; | |
893 | } | |
894 | ||
7f5a08c7 BB |
895 | /* |
896 | * Writes the user supplied payload out to a trace file. | |
897 | */ | |
0279400a | 898 | static void user_event_ftrace(struct user_event *user, struct iov_iter *i, |
2467cda1 | 899 | void *tpdata, bool *faulted) |
7f5a08c7 BB |
900 | { |
901 | struct trace_event_file *file; | |
902 | struct trace_entry *entry; | |
903 | struct trace_event_buffer event_buffer; | |
2467cda1 | 904 | size_t size = sizeof(*entry) + i->count; |
7f5a08c7 BB |
905 | |
906 | file = (struct trace_event_file *)tpdata; | |
907 | ||
908 | if (!file || | |
909 | !(file->flags & EVENT_FILE_FL_ENABLED) || | |
910 | trace_trigger_soft_disabled(file)) | |
911 | return; | |
912 | ||
913 | /* Allocates and fills trace_entry, + 1 of this is data payload */ | |
2467cda1 | 914 | entry = trace_event_buffer_reserve(&event_buffer, file, size); |
7f5a08c7 BB |
915 | |
916 | if (unlikely(!entry)) | |
917 | return; | |
918 | ||
0279400a | 919 | if (unlikely(!copy_nofault(entry + 1, i->count, i))) |
2467cda1 BB |
920 | goto discard; |
921 | ||
922 | if (!list_empty(&user->validators) && | |
923 | unlikely(user_event_validate(user, entry, size))) | |
924 | goto discard; | |
925 | ||
926 | trace_event_buffer_commit(&event_buffer); | |
927 | ||
928 | return; | |
929 | discard: | |
930 | *faulted = true; | |
931 | __trace_event_discard_commit(event_buffer.buffer, | |
932 | event_buffer.event); | |
7f5a08c7 BB |
933 | } |
934 | ||
3207d045 BB |
935 | #ifdef CONFIG_PERF_EVENTS |
936 | /* | |
768c1e7f | 937 | * Writes the user supplied payload out to perf ring buffer. |
3207d045 | 938 | */ |
0279400a | 939 | static void user_event_perf(struct user_event *user, struct iov_iter *i, |
2467cda1 | 940 | void *tpdata, bool *faulted) |
3207d045 BB |
941 | { |
942 | struct hlist_head *perf_head; | |
943 | ||
3207d045 BB |
944 | perf_head = this_cpu_ptr(user->call.perf_events); |
945 | ||
946 | if (perf_head && !hlist_empty(perf_head)) { | |
947 | struct trace_entry *perf_entry; | |
948 | struct pt_regs *regs; | |
0279400a | 949 | size_t size = sizeof(*perf_entry) + i->count; |
3207d045 BB |
950 | int context; |
951 | ||
952 | perf_entry = perf_trace_buf_alloc(ALIGN(size, 8), | |
953 | ®s, &context); | |
954 | ||
955 | if (unlikely(!perf_entry)) | |
956 | return; | |
957 | ||
958 | perf_fetch_caller_regs(regs); | |
959 | ||
2467cda1 BB |
960 | if (unlikely(!copy_nofault(perf_entry + 1, i->count, i))) |
961 | goto discard; | |
962 | ||
963 | if (!list_empty(&user->validators) && | |
964 | unlikely(user_event_validate(user, perf_entry, size))) | |
965 | goto discard; | |
3207d045 BB |
966 | |
967 | perf_trace_buf_submit(perf_entry, size, context, | |
968 | user->call.event.type, 1, regs, | |
969 | perf_head, NULL); | |
2467cda1 BB |
970 | |
971 | return; | |
972 | discard: | |
973 | *faulted = true; | |
974 | perf_swevent_put_recursion_context(context); | |
3207d045 BB |
975 | } |
976 | } | |
977 | #endif | |
978 | ||
7f5a08c7 BB |
979 | /* |
980 | * Update the register page that is shared between user processes. | |
981 | */ | |
982 | static void update_reg_page_for(struct user_event *user) | |
983 | { | |
984 | struct tracepoint *tp = &user->tracepoint; | |
985 | char status = 0; | |
986 | ||
987 | if (atomic_read(&tp->key.enabled) > 0) { | |
988 | struct tracepoint_func *probe_func_ptr; | |
989 | user_event_func_t probe_func; | |
990 | ||
991 | rcu_read_lock_sched(); | |
992 | ||
993 | probe_func_ptr = rcu_dereference_sched(tp->funcs); | |
994 | ||
995 | if (probe_func_ptr) { | |
996 | do { | |
997 | probe_func = probe_func_ptr->func; | |
998 | ||
999 | if (probe_func == user_event_ftrace) | |
1000 | status |= EVENT_STATUS_FTRACE; | |
3207d045 BB |
1001 | #ifdef CONFIG_PERF_EVENTS |
1002 | else if (probe_func == user_event_perf) | |
1003 | status |= EVENT_STATUS_PERF; | |
1004 | #endif | |
7f5a08c7 BB |
1005 | else |
1006 | status |= EVENT_STATUS_OTHER; | |
1007 | } while ((++probe_func_ptr)->func); | |
1008 | } | |
1009 | ||
1010 | rcu_read_unlock_sched(); | |
1011 | } | |
1012 | ||
39d6d08b BB |
1013 | if (status) |
1014 | user_event_register_set(user); | |
1015 | else | |
1016 | user_event_register_clear(user); | |
1017 | ||
1018 | user->status = status; | |
7f5a08c7 BB |
1019 | } |
1020 | ||
1021 | /* | |
1022 | * Register callback for our events from tracing sub-systems. | |
1023 | */ | |
1024 | static int user_event_reg(struct trace_event_call *call, | |
1025 | enum trace_reg type, | |
1026 | void *data) | |
1027 | { | |
1028 | struct user_event *user = (struct user_event *)call->data; | |
1029 | int ret = 0; | |
1030 | ||
1031 | if (!user) | |
1032 | return -ENOENT; | |
1033 | ||
1034 | switch (type) { | |
1035 | case TRACE_REG_REGISTER: | |
1036 | ret = tracepoint_probe_register(call->tp, | |
1037 | call->class->probe, | |
1038 | data); | |
1039 | if (!ret) | |
1040 | goto inc; | |
1041 | break; | |
1042 | ||
1043 | case TRACE_REG_UNREGISTER: | |
1044 | tracepoint_probe_unregister(call->tp, | |
1045 | call->class->probe, | |
1046 | data); | |
1047 | goto dec; | |
1048 | ||
3207d045 BB |
1049 | #ifdef CONFIG_PERF_EVENTS |
1050 | case TRACE_REG_PERF_REGISTER: | |
1051 | ret = tracepoint_probe_register(call->tp, | |
1052 | call->class->perf_probe, | |
1053 | data); | |
1054 | if (!ret) | |
1055 | goto inc; | |
1056 | break; | |
1057 | ||
1058 | case TRACE_REG_PERF_UNREGISTER: | |
1059 | tracepoint_probe_unregister(call->tp, | |
1060 | call->class->perf_probe, | |
1061 | data); | |
1062 | goto dec; | |
1063 | ||
1064 | case TRACE_REG_PERF_OPEN: | |
1065 | case TRACE_REG_PERF_CLOSE: | |
1066 | case TRACE_REG_PERF_ADD: | |
1067 | case TRACE_REG_PERF_DEL: | |
7f5a08c7 | 1068 | break; |
3207d045 | 1069 | #endif |
7f5a08c7 BB |
1070 | } |
1071 | ||
1072 | return ret; | |
1073 | inc: | |
d401b724 | 1074 | refcount_inc(&user->refcnt); |
7f5a08c7 BB |
1075 | update_reg_page_for(user); |
1076 | return 0; | |
1077 | dec: | |
1078 | update_reg_page_for(user); | |
d401b724 | 1079 | refcount_dec(&user->refcnt); |
7f5a08c7 BB |
1080 | return 0; |
1081 | } | |
1082 | ||
1083 | static int user_event_create(const char *raw_command) | |
1084 | { | |
e5d27181 | 1085 | struct user_event_group *group; |
7f5a08c7 BB |
1086 | struct user_event *user; |
1087 | char *name; | |
1088 | int ret; | |
1089 | ||
1090 | if (!str_has_prefix(raw_command, USER_EVENTS_PREFIX)) | |
1091 | return -ECANCELED; | |
1092 | ||
1093 | raw_command += USER_EVENTS_PREFIX_LEN; | |
1094 | raw_command = skip_spaces(raw_command); | |
1095 | ||
1096 | name = kstrdup(raw_command, GFP_KERNEL); | |
1097 | ||
1098 | if (!name) | |
1099 | return -ENOMEM; | |
1100 | ||
e5d27181 BB |
1101 | group = current_user_event_group(); |
1102 | ||
ccc6e590 XJ |
1103 | if (!group) { |
1104 | kfree(name); | |
e5d27181 | 1105 | return -ENOENT; |
ccc6e590 | 1106 | } |
e5d27181 BB |
1107 | |
1108 | mutex_lock(&group->reg_mutex); | |
7e348b32 | 1109 | |
e5d27181 | 1110 | ret = user_event_parse_cmd(group, name, &user); |
7e348b32 BB |
1111 | |
1112 | if (!ret) | |
d401b724 | 1113 | refcount_dec(&user->refcnt); |
7e348b32 | 1114 | |
e5d27181 | 1115 | mutex_unlock(&group->reg_mutex); |
7f5a08c7 BB |
1116 | |
1117 | if (ret) | |
1118 | kfree(name); | |
1119 | ||
1120 | return ret; | |
1121 | } | |
1122 | ||
1123 | static int user_event_show(struct seq_file *m, struct dyn_event *ev) | |
1124 | { | |
1125 | struct user_event *user = container_of(ev, struct user_event, devent); | |
1126 | struct ftrace_event_field *field, *next; | |
1127 | struct list_head *head; | |
1128 | int depth = 0; | |
1129 | ||
1130 | seq_printf(m, "%s%s", USER_EVENTS_PREFIX, EVENT_NAME(user)); | |
1131 | ||
1132 | head = trace_get_fields(&user->call); | |
1133 | ||
1134 | list_for_each_entry_safe_reverse(field, next, head, link) { | |
1135 | if (depth == 0) | |
1136 | seq_puts(m, " "); | |
1137 | else | |
1138 | seq_puts(m, "; "); | |
1139 | ||
1140 | seq_printf(m, "%s %s", field->type, field->name); | |
1141 | ||
1142 | if (str_has_prefix(field->type, "struct ")) | |
1143 | seq_printf(m, " %d", field->size); | |
1144 | ||
1145 | depth++; | |
1146 | } | |
1147 | ||
1148 | seq_puts(m, "\n"); | |
1149 | ||
1150 | return 0; | |
1151 | } | |
1152 | ||
1153 | static bool user_event_is_busy(struct dyn_event *ev) | |
1154 | { | |
1155 | struct user_event *user = container_of(ev, struct user_event, devent); | |
1156 | ||
d401b724 | 1157 | return !user_event_last_ref(user); |
7f5a08c7 BB |
1158 | } |
1159 | ||
1160 | static int user_event_free(struct dyn_event *ev) | |
1161 | { | |
1162 | struct user_event *user = container_of(ev, struct user_event, devent); | |
1163 | ||
d401b724 | 1164 | if (!user_event_last_ref(user)) |
7f5a08c7 BB |
1165 | return -EBUSY; |
1166 | ||
1167 | return destroy_user_event(user); | |
1168 | } | |
1169 | ||
9aed4e15 BB |
1170 | static bool user_field_match(struct ftrace_event_field *field, int argc, |
1171 | const char **argv, int *iout) | |
1172 | { | |
e6f89a14 | 1173 | char *field_name = NULL, *dyn_field_name = NULL; |
9aed4e15 | 1174 | bool colon = false, match = false; |
e6f89a14 | 1175 | int dyn_len, len; |
9aed4e15 | 1176 | |
e6f89a14 | 1177 | if (*iout >= argc) |
9aed4e15 BB |
1178 | return false; |
1179 | ||
e6f89a14 BB |
1180 | dyn_len = user_dyn_field_set_string(argc, argv, iout, dyn_field_name, |
1181 | 0, &colon); | |
9aed4e15 | 1182 | |
e6f89a14 | 1183 | len = user_field_set_string(field, field_name, 0, colon); |
9aed4e15 | 1184 | |
e6f89a14 BB |
1185 | if (dyn_len != len) |
1186 | return false; | |
9aed4e15 | 1187 | |
e6f89a14 BB |
1188 | dyn_field_name = kmalloc(dyn_len, GFP_KERNEL); |
1189 | field_name = kmalloc(len, GFP_KERNEL); | |
9aed4e15 | 1190 | |
e6f89a14 BB |
1191 | if (!dyn_field_name || !field_name) |
1192 | goto out; | |
9aed4e15 | 1193 | |
e6f89a14 BB |
1194 | user_dyn_field_set_string(argc, argv, iout, dyn_field_name, |
1195 | dyn_len, &colon); | |
9aed4e15 | 1196 | |
e6f89a14 | 1197 | user_field_set_string(field, field_name, len, colon); |
9aed4e15 | 1198 | |
e6f89a14 | 1199 | match = strcmp(dyn_field_name, field_name) == 0; |
9aed4e15 | 1200 | out: |
e6f89a14 | 1201 | kfree(dyn_field_name); |
9aed4e15 BB |
1202 | kfree(field_name); |
1203 | ||
1204 | return match; | |
1205 | } | |
1206 | ||
1207 | static bool user_fields_match(struct user_event *user, int argc, | |
1208 | const char **argv) | |
1209 | { | |
1210 | struct ftrace_event_field *field, *next; | |
1211 | struct list_head *head = &user->fields; | |
1212 | int i = 0; | |
1213 | ||
1214 | list_for_each_entry_safe_reverse(field, next, head, link) | |
1215 | if (!user_field_match(field, argc, argv, &i)) | |
1216 | return false; | |
1217 | ||
1218 | if (i != argc) | |
1219 | return false; | |
1220 | ||
1221 | return true; | |
1222 | } | |
1223 | ||
7f5a08c7 BB |
1224 | static bool user_event_match(const char *system, const char *event, |
1225 | int argc, const char **argv, struct dyn_event *ev) | |
1226 | { | |
1227 | struct user_event *user = container_of(ev, struct user_event, devent); | |
9aed4e15 | 1228 | bool match; |
7f5a08c7 | 1229 | |
9aed4e15 | 1230 | match = strcmp(EVENT_NAME(user), event) == 0 && |
7f5a08c7 | 1231 | (!system || strcmp(system, USER_EVENTS_SYSTEM) == 0); |
9aed4e15 BB |
1232 | |
1233 | if (match && argc > 0) | |
1234 | match = user_fields_match(user, argc, argv); | |
1235 | ||
1236 | return match; | |
7f5a08c7 BB |
1237 | } |
1238 | ||
1239 | static struct dyn_event_operations user_event_dops = { | |
1240 | .create = user_event_create, | |
1241 | .show = user_event_show, | |
1242 | .is_busy = user_event_is_busy, | |
1243 | .free = user_event_free, | |
1244 | .match = user_event_match, | |
1245 | }; | |
1246 | ||
1247 | static int user_event_trace_register(struct user_event *user) | |
1248 | { | |
1249 | int ret; | |
1250 | ||
1251 | ret = register_trace_event(&user->call.event); | |
1252 | ||
1253 | if (!ret) | |
1254 | return -ENODEV; | |
1255 | ||
089331d4 | 1256 | ret = user_event_set_call_visible(user, true); |
7f5a08c7 BB |
1257 | |
1258 | if (ret) | |
1259 | unregister_trace_event(&user->call.event); | |
1260 | ||
1261 | return ret; | |
1262 | } | |
1263 | ||
1264 | /* | |
1265 | * Parses the event name, arguments and flags then registers if successful. | |
1266 | * The name buffer lifetime is owned by this method for success cases only. | |
7e348b32 | 1267 | * Upon success the returned user_event has its ref count increased by 1. |
7f5a08c7 | 1268 | */ |
e5d27181 BB |
1269 | static int user_event_parse(struct user_event_group *group, char *name, |
1270 | char *args, char *flags, | |
7f5a08c7 BB |
1271 | struct user_event **newuser) |
1272 | { | |
1273 | int ret; | |
1274 | int index; | |
1275 | u32 key; | |
7e348b32 BB |
1276 | struct user_event *user; |
1277 | ||
1278 | /* Prevent dyn_event from racing */ | |
1279 | mutex_lock(&event_mutex); | |
e5d27181 | 1280 | user = find_user_event(group, name, &key); |
7e348b32 | 1281 | mutex_unlock(&event_mutex); |
7f5a08c7 BB |
1282 | |
1283 | if (user) { | |
1284 | *newuser = user; | |
1285 | /* | |
1286 | * Name is allocated by caller, free it since it already exists. | |
1287 | * Caller only worries about failure cases for freeing. | |
1288 | */ | |
1289 | kfree(name); | |
1290 | return 0; | |
1291 | } | |
1292 | ||
e5d27181 | 1293 | index = find_first_zero_bit(group->page_bitmap, MAX_EVENTS); |
7f5a08c7 BB |
1294 | |
1295 | if (index == MAX_EVENTS) | |
1296 | return -EMFILE; | |
1297 | ||
1298 | user = kzalloc(sizeof(*user), GFP_KERNEL); | |
1299 | ||
1300 | if (!user) | |
1301 | return -ENOMEM; | |
1302 | ||
1303 | INIT_LIST_HEAD(&user->class.fields); | |
1304 | INIT_LIST_HEAD(&user->fields); | |
2467cda1 | 1305 | INIT_LIST_HEAD(&user->validators); |
7f5a08c7 | 1306 | |
e5d27181 | 1307 | user->group = group; |
7f5a08c7 BB |
1308 | user->tracepoint.name = name; |
1309 | ||
7f5a08c7 BB |
1310 | ret = user_event_parse_fields(user, args); |
1311 | ||
1312 | if (ret) | |
1313 | goto put_user; | |
1314 | ||
aa3b2b4c BB |
1315 | ret = user_event_create_print_fmt(user); |
1316 | ||
1317 | if (ret) | |
1318 | goto put_user; | |
7f5a08c7 BB |
1319 | |
1320 | user->call.data = user; | |
1321 | user->call.class = &user->class; | |
1322 | user->call.name = name; | |
1323 | user->call.flags = TRACE_EVENT_FL_TRACEPOINT; | |
1324 | user->call.tp = &user->tracepoint; | |
1325 | user->call.event.funcs = &user_event_funcs; | |
e5d27181 | 1326 | user->class.system = group->system_name; |
7f5a08c7 | 1327 | |
7f5a08c7 BB |
1328 | user->class.fields_array = user_event_fields_array; |
1329 | user->class.get_fields = user_event_get_fields; | |
1330 | user->class.reg = user_event_reg; | |
1331 | user->class.probe = user_event_ftrace; | |
3207d045 BB |
1332 | #ifdef CONFIG_PERF_EVENTS |
1333 | user->class.perf_probe = user_event_perf; | |
1334 | #endif | |
7f5a08c7 BB |
1335 | |
1336 | mutex_lock(&event_mutex); | |
efe34e99 | 1337 | |
7f5a08c7 | 1338 | ret = user_event_trace_register(user); |
7f5a08c7 BB |
1339 | |
1340 | if (ret) | |
efe34e99 | 1341 | goto put_user_lock; |
7f5a08c7 BB |
1342 | |
1343 | user->index = index; | |
7e348b32 | 1344 | |
d401b724 BB |
1345 | /* Ensure we track self ref and caller ref (2) */ |
1346 | refcount_set(&user->refcnt, 2); | |
7e348b32 | 1347 | |
7f5a08c7 BB |
1348 | dyn_event_init(&user->devent, &user_event_dops); |
1349 | dyn_event_add(&user->devent, &user->call); | |
e5d27181 BB |
1350 | set_bit(user->index, group->page_bitmap); |
1351 | hash_add(group->register_table, &user->node, key); | |
7f5a08c7 | 1352 | |
efe34e99 BB |
1353 | mutex_unlock(&event_mutex); |
1354 | ||
7f5a08c7 BB |
1355 | *newuser = user; |
1356 | return 0; | |
efe34e99 BB |
1357 | put_user_lock: |
1358 | mutex_unlock(&event_mutex); | |
7f5a08c7 BB |
1359 | put_user: |
1360 | user_event_destroy_fields(user); | |
2467cda1 | 1361 | user_event_destroy_validators(user); |
4bded7af | 1362 | kfree(user->call.print_fmt); |
7f5a08c7 BB |
1363 | kfree(user); |
1364 | return ret; | |
1365 | } | |
1366 | ||
1367 | /* | |
1368 | * Deletes a previously created event if it is no longer being used. | |
1369 | */ | |
e5d27181 | 1370 | static int delete_user_event(struct user_event_group *group, char *name) |
7f5a08c7 BB |
1371 | { |
1372 | u32 key; | |
e5d27181 | 1373 | struct user_event *user = find_user_event(group, name, &key); |
7f5a08c7 BB |
1374 | |
1375 | if (!user) | |
1376 | return -ENOENT; | |
1377 | ||
d401b724 | 1378 | refcount_dec(&user->refcnt); |
7e348b32 | 1379 | |
d401b724 BB |
1380 | if (!user_event_last_ref(user)) |
1381 | return -EBUSY; | |
7f5a08c7 | 1382 | |
d401b724 | 1383 | return destroy_user_event(user); |
7f5a08c7 BB |
1384 | } |
1385 | ||
1386 | /* | |
1387 | * Validates the user payload and writes via iterator. | |
1388 | */ | |
1389 | static ssize_t user_events_write_core(struct file *file, struct iov_iter *i) | |
1390 | { | |
e5d27181 | 1391 | struct user_event_file_info *info = file->private_data; |
7f5a08c7 BB |
1392 | struct user_event_refs *refs; |
1393 | struct user_event *user = NULL; | |
1394 | struct tracepoint *tp; | |
1395 | ssize_t ret = i->count; | |
1396 | int idx; | |
1397 | ||
1398 | if (unlikely(copy_from_iter(&idx, sizeof(idx), i) != sizeof(idx))) | |
1399 | return -EFAULT; | |
1400 | ||
1401 | rcu_read_lock_sched(); | |
1402 | ||
e5d27181 | 1403 | refs = rcu_dereference_sched(info->refs); |
7f5a08c7 BB |
1404 | |
1405 | /* | |
1406 | * The refs->events array is protected by RCU, and new items may be | |
1407 | * added. But the user retrieved from indexing into the events array | |
1408 | * shall be immutable while the file is opened. | |
1409 | */ | |
1410 | if (likely(refs && idx < refs->count)) | |
1411 | user = refs->events[idx]; | |
1412 | ||
1413 | rcu_read_unlock_sched(); | |
1414 | ||
1415 | if (unlikely(user == NULL)) | |
1416 | return -ENOENT; | |
1417 | ||
2467cda1 BB |
1418 | if (unlikely(i->count < user->min_size)) |
1419 | return -EINVAL; | |
1420 | ||
7f5a08c7 BB |
1421 | tp = &user->tracepoint; |
1422 | ||
1423 | /* | |
1424 | * It's possible key.enabled disables after this check, however | |
1425 | * we don't mind if a few events are included in this condition. | |
1426 | */ | |
1427 | if (likely(atomic_read(&tp->key.enabled) > 0)) { | |
1428 | struct tracepoint_func *probe_func_ptr; | |
1429 | user_event_func_t probe_func; | |
0279400a | 1430 | struct iov_iter copy; |
7f5a08c7 | 1431 | void *tpdata; |
2467cda1 | 1432 | bool faulted; |
7f5a08c7 | 1433 | |
0279400a BB |
1434 | if (unlikely(fault_in_iov_iter_readable(i, i->count))) |
1435 | return -EFAULT; | |
7f5a08c7 | 1436 | |
2467cda1 BB |
1437 | faulted = false; |
1438 | ||
7f5a08c7 BB |
1439 | rcu_read_lock_sched(); |
1440 | ||
1441 | probe_func_ptr = rcu_dereference_sched(tp->funcs); | |
1442 | ||
1443 | if (probe_func_ptr) { | |
1444 | do { | |
0279400a | 1445 | copy = *i; |
7f5a08c7 BB |
1446 | probe_func = probe_func_ptr->func; |
1447 | tpdata = probe_func_ptr->data; | |
2467cda1 | 1448 | probe_func(user, ©, tpdata, &faulted); |
7f5a08c7 BB |
1449 | } while ((++probe_func_ptr)->func); |
1450 | } | |
1451 | ||
1452 | rcu_read_unlock_sched(); | |
2467cda1 BB |
1453 | |
1454 | if (unlikely(faulted)) | |
1455 | return -EFAULT; | |
7f5a08c7 BB |
1456 | } |
1457 | ||
1458 | return ret; | |
1459 | } | |
1460 | ||
e5d27181 BB |
1461 | static int user_events_open(struct inode *node, struct file *file) |
1462 | { | |
1463 | struct user_event_group *group; | |
1464 | struct user_event_file_info *info; | |
1465 | ||
1466 | group = current_user_event_group(); | |
1467 | ||
1468 | if (!group) | |
1469 | return -ENOENT; | |
1470 | ||
1471 | info = kzalloc(sizeof(*info), GFP_KERNEL); | |
1472 | ||
1473 | if (!info) | |
1474 | return -ENOMEM; | |
1475 | ||
1476 | info->group = group; | |
1477 | ||
1478 | file->private_data = info; | |
1479 | ||
1480 | return 0; | |
1481 | } | |
1482 | ||
7f5a08c7 BB |
1483 | static ssize_t user_events_write(struct file *file, const char __user *ubuf, |
1484 | size_t count, loff_t *ppos) | |
1485 | { | |
1486 | struct iovec iov; | |
1487 | struct iov_iter i; | |
1488 | ||
1489 | if (unlikely(*ppos != 0)) | |
1490 | return -EFAULT; | |
1491 | ||
de4eda9d | 1492 | if (unlikely(import_single_range(ITER_SOURCE, (char __user *)ubuf, |
95f18760 | 1493 | count, &iov, &i))) |
7f5a08c7 BB |
1494 | return -EFAULT; |
1495 | ||
1496 | return user_events_write_core(file, &i); | |
1497 | } | |
1498 | ||
1499 | static ssize_t user_events_write_iter(struct kiocb *kp, struct iov_iter *i) | |
1500 | { | |
1501 | return user_events_write_core(kp->ki_filp, i); | |
1502 | } | |
1503 | ||
e5d27181 BB |
1504 | static int user_events_ref_add(struct user_event_file_info *info, |
1505 | struct user_event *user) | |
7f5a08c7 | 1506 | { |
e5d27181 | 1507 | struct user_event_group *group = info->group; |
7f5a08c7 BB |
1508 | struct user_event_refs *refs, *new_refs; |
1509 | int i, size, count = 0; | |
1510 | ||
e5d27181 BB |
1511 | refs = rcu_dereference_protected(info->refs, |
1512 | lockdep_is_held(&group->reg_mutex)); | |
7f5a08c7 BB |
1513 | |
1514 | if (refs) { | |
1515 | count = refs->count; | |
1516 | ||
1517 | for (i = 0; i < count; ++i) | |
1518 | if (refs->events[i] == user) | |
1519 | return i; | |
1520 | } | |
1521 | ||
1522 | size = struct_size(refs, events, count + 1); | |
1523 | ||
1524 | new_refs = kzalloc(size, GFP_KERNEL); | |
1525 | ||
1526 | if (!new_refs) | |
1527 | return -ENOMEM; | |
1528 | ||
1529 | new_refs->count = count + 1; | |
1530 | ||
1531 | for (i = 0; i < count; ++i) | |
1532 | new_refs->events[i] = refs->events[i]; | |
1533 | ||
1534 | new_refs->events[i] = user; | |
1535 | ||
d401b724 | 1536 | refcount_inc(&user->refcnt); |
7f5a08c7 | 1537 | |
e5d27181 | 1538 | rcu_assign_pointer(info->refs, new_refs); |
7f5a08c7 BB |
1539 | |
1540 | if (refs) | |
1541 | kfree_rcu(refs, rcu); | |
1542 | ||
1543 | return i; | |
1544 | } | |
1545 | ||
1546 | static long user_reg_get(struct user_reg __user *ureg, struct user_reg *kreg) | |
1547 | { | |
1548 | u32 size; | |
1549 | long ret; | |
1550 | ||
1551 | ret = get_user(size, &ureg->size); | |
1552 | ||
1553 | if (ret) | |
1554 | return ret; | |
1555 | ||
1556 | if (size > PAGE_SIZE) | |
1557 | return -E2BIG; | |
1558 | ||
39d6d08b BB |
1559 | if (size < offsetofend(struct user_reg, write_index)) |
1560 | return -EINVAL; | |
1561 | ||
1562 | ret = copy_struct_from_user(kreg, sizeof(*kreg), ureg, size); | |
1563 | ||
1564 | if (ret) | |
1565 | return ret; | |
1566 | ||
1567 | kreg->size = size; | |
1568 | ||
1569 | return 0; | |
7f5a08c7 BB |
1570 | } |
1571 | ||
1572 | /* | |
1573 | * Registers a user_event on behalf of a user process. | |
1574 | */ | |
e5d27181 BB |
1575 | static long user_events_ioctl_reg(struct user_event_file_info *info, |
1576 | unsigned long uarg) | |
7f5a08c7 BB |
1577 | { |
1578 | struct user_reg __user *ureg = (struct user_reg __user *)uarg; | |
1579 | struct user_reg reg; | |
1580 | struct user_event *user; | |
1581 | char *name; | |
1582 | long ret; | |
1583 | ||
1584 | ret = user_reg_get(ureg, ®); | |
1585 | ||
1586 | if (ret) | |
1587 | return ret; | |
1588 | ||
1589 | name = strndup_user((const char __user *)(uintptr_t)reg.name_args, | |
1590 | MAX_EVENT_DESC); | |
1591 | ||
1592 | if (IS_ERR(name)) { | |
1593 | ret = PTR_ERR(name); | |
1594 | return ret; | |
1595 | } | |
1596 | ||
e5d27181 | 1597 | ret = user_event_parse_cmd(info->group, name, &user); |
7f5a08c7 BB |
1598 | |
1599 | if (ret) { | |
1600 | kfree(name); | |
1601 | return ret; | |
1602 | } | |
1603 | ||
e5d27181 | 1604 | ret = user_events_ref_add(info, user); |
7f5a08c7 | 1605 | |
7e348b32 | 1606 | /* No longer need parse ref, ref_add either worked or not */ |
d401b724 | 1607 | refcount_dec(&user->refcnt); |
7e348b32 | 1608 | |
7f5a08c7 BB |
1609 | /* Positive number is index and valid */ |
1610 | if (ret < 0) | |
1611 | return ret; | |
1612 | ||
1613 | put_user((u32)ret, &ureg->write_index); | |
39d6d08b | 1614 | put_user(user->index, &ureg->status_bit); |
7f5a08c7 BB |
1615 | |
1616 | return 0; | |
1617 | } | |
1618 | ||
1619 | /* | |
1620 | * Deletes a user_event on behalf of a user process. | |
1621 | */ | |
e5d27181 BB |
1622 | static long user_events_ioctl_del(struct user_event_file_info *info, |
1623 | unsigned long uarg) | |
7f5a08c7 BB |
1624 | { |
1625 | void __user *ubuf = (void __user *)uarg; | |
1626 | char *name; | |
1627 | long ret; | |
1628 | ||
1629 | name = strndup_user(ubuf, MAX_EVENT_DESC); | |
1630 | ||
1631 | if (IS_ERR(name)) | |
1632 | return PTR_ERR(name); | |
1633 | ||
7e348b32 BB |
1634 | /* event_mutex prevents dyn_event from racing */ |
1635 | mutex_lock(&event_mutex); | |
e5d27181 | 1636 | ret = delete_user_event(info->group, name); |
7e348b32 | 1637 | mutex_unlock(&event_mutex); |
7f5a08c7 BB |
1638 | |
1639 | kfree(name); | |
1640 | ||
1641 | return ret; | |
1642 | } | |
1643 | ||
1644 | /* | |
1645 | * Handles the ioctl from user mode to register or alter operations. | |
1646 | */ | |
1647 | static long user_events_ioctl(struct file *file, unsigned int cmd, | |
1648 | unsigned long uarg) | |
1649 | { | |
e5d27181 BB |
1650 | struct user_event_file_info *info = file->private_data; |
1651 | struct user_event_group *group = info->group; | |
7f5a08c7 BB |
1652 | long ret = -ENOTTY; |
1653 | ||
1654 | switch (cmd) { | |
1655 | case DIAG_IOCSREG: | |
e5d27181 BB |
1656 | mutex_lock(&group->reg_mutex); |
1657 | ret = user_events_ioctl_reg(info, uarg); | |
1658 | mutex_unlock(&group->reg_mutex); | |
7f5a08c7 BB |
1659 | break; |
1660 | ||
1661 | case DIAG_IOCSDEL: | |
e5d27181 BB |
1662 | mutex_lock(&group->reg_mutex); |
1663 | ret = user_events_ioctl_del(info, uarg); | |
1664 | mutex_unlock(&group->reg_mutex); | |
7f5a08c7 BB |
1665 | break; |
1666 | } | |
1667 | ||
1668 | return ret; | |
1669 | } | |
1670 | ||
1671 | /* | |
1672 | * Handles the final close of the file from user mode. | |
1673 | */ | |
1674 | static int user_events_release(struct inode *node, struct file *file) | |
1675 | { | |
e5d27181 BB |
1676 | struct user_event_file_info *info = file->private_data; |
1677 | struct user_event_group *group; | |
7f5a08c7 BB |
1678 | struct user_event_refs *refs; |
1679 | struct user_event *user; | |
1680 | int i; | |
1681 | ||
e5d27181 BB |
1682 | if (!info) |
1683 | return -EINVAL; | |
1684 | ||
1685 | group = info->group; | |
1686 | ||
7f5a08c7 BB |
1687 | /* |
1688 | * Ensure refs cannot change under any situation by taking the | |
1689 | * register mutex during the final freeing of the references. | |
1690 | */ | |
e5d27181 | 1691 | mutex_lock(&group->reg_mutex); |
7f5a08c7 | 1692 | |
e5d27181 | 1693 | refs = info->refs; |
7f5a08c7 BB |
1694 | |
1695 | if (!refs) | |
1696 | goto out; | |
1697 | ||
1698 | /* | |
1699 | * The lifetime of refs has reached an end, it's tied to this file. | |
1700 | * The underlying user_events are ref counted, and cannot be freed. | |
1701 | * After this decrement, the user_events may be freed elsewhere. | |
1702 | */ | |
1703 | for (i = 0; i < refs->count; ++i) { | |
1704 | user = refs->events[i]; | |
1705 | ||
1706 | if (user) | |
d401b724 | 1707 | refcount_dec(&user->refcnt); |
7f5a08c7 BB |
1708 | } |
1709 | out: | |
1710 | file->private_data = NULL; | |
1711 | ||
e5d27181 | 1712 | mutex_unlock(&group->reg_mutex); |
7f5a08c7 BB |
1713 | |
1714 | kfree(refs); | |
e5d27181 | 1715 | kfree(info); |
7f5a08c7 BB |
1716 | |
1717 | return 0; | |
1718 | } | |
1719 | ||
1720 | static const struct file_operations user_data_fops = { | |
e5d27181 | 1721 | .open = user_events_open, |
7f5a08c7 BB |
1722 | .write = user_events_write, |
1723 | .write_iter = user_events_write_iter, | |
1724 | .unlocked_ioctl = user_events_ioctl, | |
1725 | .release = user_events_release, | |
1726 | }; | |
1727 | ||
e5d27181 BB |
1728 | static struct user_event_group *user_status_group(struct file *file) |
1729 | { | |
1730 | struct seq_file *m = file->private_data; | |
1731 | ||
1732 | if (!m) | |
1733 | return NULL; | |
1734 | ||
1735 | return m->private; | |
1736 | } | |
1737 | ||
7f5a08c7 BB |
1738 | /* |
1739 | * Maps the shared page into the user process for checking if event is enabled. | |
1740 | */ | |
1741 | static int user_status_mmap(struct file *file, struct vm_area_struct *vma) | |
1742 | { | |
e5d27181 BB |
1743 | char *pages; |
1744 | struct user_event_group *group = user_status_group(file); | |
7f5a08c7 BB |
1745 | unsigned long size = vma->vm_end - vma->vm_start; |
1746 | ||
39d6d08b | 1747 | if (size != MAX_BYTES) |
7f5a08c7 BB |
1748 | return -EINVAL; |
1749 | ||
e5d27181 BB |
1750 | if (!group) |
1751 | return -EINVAL; | |
1752 | ||
1753 | pages = group->register_page_data; | |
1754 | ||
7f5a08c7 | 1755 | return remap_pfn_range(vma, vma->vm_start, |
e5d27181 | 1756 | virt_to_phys(pages) >> PAGE_SHIFT, |
7f5a08c7 BB |
1757 | size, vm_get_page_prot(VM_READ)); |
1758 | } | |
1759 | ||
1760 | static void *user_seq_start(struct seq_file *m, loff_t *pos) | |
1761 | { | |
1762 | if (*pos) | |
1763 | return NULL; | |
1764 | ||
1765 | return (void *)1; | |
1766 | } | |
1767 | ||
1768 | static void *user_seq_next(struct seq_file *m, void *p, loff_t *pos) | |
1769 | { | |
1770 | ++*pos; | |
1771 | return NULL; | |
1772 | } | |
1773 | ||
1774 | static void user_seq_stop(struct seq_file *m, void *p) | |
1775 | { | |
1776 | } | |
1777 | ||
1778 | static int user_seq_show(struct seq_file *m, void *p) | |
1779 | { | |
e5d27181 | 1780 | struct user_event_group *group = m->private; |
7f5a08c7 BB |
1781 | struct user_event *user; |
1782 | char status; | |
1783 | int i, active = 0, busy = 0, flags; | |
1784 | ||
e5d27181 BB |
1785 | if (!group) |
1786 | return -EINVAL; | |
1787 | ||
1788 | mutex_lock(&group->reg_mutex); | |
7f5a08c7 | 1789 | |
e5d27181 | 1790 | hash_for_each(group->register_table, i, user, node) { |
39d6d08b | 1791 | status = user->status; |
7f5a08c7 BB |
1792 | flags = user->flags; |
1793 | ||
1794 | seq_printf(m, "%d:%s", user->index, EVENT_NAME(user)); | |
1795 | ||
1796 | if (flags != 0 || status != 0) | |
1797 | seq_puts(m, " #"); | |
1798 | ||
1799 | if (status != 0) { | |
1800 | seq_puts(m, " Used by"); | |
1801 | if (status & EVENT_STATUS_FTRACE) | |
1802 | seq_puts(m, " ftrace"); | |
1803 | if (status & EVENT_STATUS_PERF) | |
1804 | seq_puts(m, " perf"); | |
1805 | if (status & EVENT_STATUS_OTHER) | |
1806 | seq_puts(m, " other"); | |
1807 | busy++; | |
1808 | } | |
1809 | ||
7f5a08c7 BB |
1810 | seq_puts(m, "\n"); |
1811 | active++; | |
1812 | } | |
1813 | ||
e5d27181 | 1814 | mutex_unlock(&group->reg_mutex); |
7f5a08c7 BB |
1815 | |
1816 | seq_puts(m, "\n"); | |
1817 | seq_printf(m, "Active: %d\n", active); | |
1818 | seq_printf(m, "Busy: %d\n", busy); | |
1819 | seq_printf(m, "Max: %ld\n", MAX_EVENTS); | |
1820 | ||
1821 | return 0; | |
1822 | } | |
1823 | ||
1824 | static const struct seq_operations user_seq_ops = { | |
1825 | .start = user_seq_start, | |
1826 | .next = user_seq_next, | |
1827 | .stop = user_seq_stop, | |
1828 | .show = user_seq_show, | |
1829 | }; | |
1830 | ||
1831 | static int user_status_open(struct inode *node, struct file *file) | |
1832 | { | |
e5d27181 BB |
1833 | struct user_event_group *group; |
1834 | int ret; | |
1835 | ||
1836 | group = current_user_event_group(); | |
1837 | ||
1838 | if (!group) | |
1839 | return -ENOENT; | |
1840 | ||
1841 | ret = seq_open(file, &user_seq_ops); | |
1842 | ||
1843 | if (!ret) { | |
1844 | /* Chain group to seq_file */ | |
1845 | struct seq_file *m = file->private_data; | |
1846 | ||
1847 | m->private = group; | |
1848 | } | |
1849 | ||
1850 | return ret; | |
7f5a08c7 BB |
1851 | } |
1852 | ||
1853 | static const struct file_operations user_status_fops = { | |
1854 | .open = user_status_open, | |
1855 | .mmap = user_status_mmap, | |
1856 | .read = seq_read, | |
1857 | .llseek = seq_lseek, | |
1858 | .release = seq_release, | |
1859 | }; | |
1860 | ||
1861 | /* | |
1862 | * Creates a set of tracefs files to allow user mode interactions. | |
1863 | */ | |
1864 | static int create_user_tracefs(void) | |
1865 | { | |
1866 | struct dentry *edata, *emmap; | |
1867 | ||
1868 | edata = tracefs_create_file("user_events_data", TRACE_MODE_WRITE, | |
1869 | NULL, NULL, &user_data_fops); | |
1870 | ||
1871 | if (!edata) { | |
1872 | pr_warn("Could not create tracefs 'user_events_data' entry\n"); | |
1873 | goto err; | |
1874 | } | |
1875 | ||
1876 | /* mmap with MAP_SHARED requires writable fd */ | |
1877 | emmap = tracefs_create_file("user_events_status", TRACE_MODE_WRITE, | |
1878 | NULL, NULL, &user_status_fops); | |
1879 | ||
1880 | if (!emmap) { | |
1881 | tracefs_remove(edata); | |
1882 | pr_warn("Could not create tracefs 'user_events_mmap' entry\n"); | |
1883 | goto err; | |
1884 | } | |
1885 | ||
1886 | return 0; | |
1887 | err: | |
1888 | return -ENODEV; | |
1889 | } | |
1890 | ||
7f5a08c7 BB |
1891 | static int __init trace_events_user_init(void) |
1892 | { | |
1893 | int ret; | |
1894 | ||
e5d27181 | 1895 | init_group = user_event_group_create(&init_user_ns); |
7f5a08c7 | 1896 | |
e5d27181 | 1897 | if (!init_group) |
7f5a08c7 | 1898 | return -ENOMEM; |
7f5a08c7 BB |
1899 | |
1900 | ret = create_user_tracefs(); | |
1901 | ||
1902 | if (ret) { | |
1903 | pr_warn("user_events could not register with tracefs\n"); | |
e5d27181 BB |
1904 | user_event_group_destroy(init_group); |
1905 | init_group = NULL; | |
7f5a08c7 BB |
1906 | return ret; |
1907 | } | |
1908 | ||
1909 | if (dyn_event_register(&user_event_dops)) | |
1910 | pr_warn("user_events could not register with dyn_events\n"); | |
1911 | ||
1912 | return 0; | |
1913 | } | |
1914 | ||
1915 | fs_initcall(trace_events_user_init); |