Commit | Line | Data |
---|---|---|
ce5aef0b | 1 | /* |
7dd08bec | 2 | * lttng-probes.c |
ce5aef0b | 3 | * |
ce5aef0b MD |
4 | * Holds LTTng probes registry. |
5 | * | |
e92f3e28 MD |
6 | * Copyright 2010-2012 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
7 | * | |
8 | * This library is free software; you can redistribute it and/or | |
9 | * modify it under the terms of the GNU Lesser General Public | |
10 | * License as published by the Free Software Foundation; only | |
11 | * version 2.1 of the License. | |
12 | * | |
13 | * This library is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | * Lesser General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU Lesser General Public | |
19 | * License along with this library; if not, write to the Free Software | |
20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
ce5aef0b MD |
21 | */ |
22 | ||
3fbec7dc | 23 | #define _LGPL_SOURCE |
8d8a24c8 MD |
24 | #include <string.h> |
25 | #include <errno.h> | |
26 | #include <urcu/list.h> | |
1f18504e | 27 | #include <urcu/hlist.h> |
4318ae1b | 28 | #include <lttng/ust-events.h> |
902e1379 | 29 | #include <lttng/tracepoint.h> |
d8de1354 | 30 | #include "tracepoint-internal.h" |
a3bb4b27 | 31 | #include <assert.h> |
c8fcf224 | 32 | #include <helper.h> |
48740cab | 33 | #include <ctype.h> |
ce5aef0b | 34 | |
7dd08bec | 35 | #include "lttng-tracer-core.h" |
1f18504e MD |
36 | #include "jhash.h" |
37 | #include "error.h" | |
d8d2416d | 38 | #include "ust-events-internal.h" |
8165c8da MD |
39 | |
40 | /* | |
17dfb34b | 41 | * probe list is protected by ust_lock()/ust_unlock(). |
8165c8da | 42 | */ |
ac69b35b | 43 | static CDS_LIST_HEAD(_probe_list); |
e58095ef | 44 | |
6715d7d1 MD |
45 | /* |
46 | * List of probes registered by not yet processed. | |
47 | */ | |
48 | static CDS_LIST_HEAD(lazy_probe_init); | |
df854e41 | 49 | |
6715d7d1 MD |
50 | /* |
51 | * lazy_nesting counter ensures we don't trigger lazy probe registration | |
52 | * fixup while we are performing the fixup. It is protected by the ust | |
53 | * mutex. | |
54 | */ | |
55 | static int lazy_nesting; | |
df854e41 | 56 | |
6715d7d1 MD |
57 | /* |
58 | * Called under ust lock. | |
59 | */ | |
ce5aef0b | 60 | static |
48205d60 | 61 | int check_event_provider(struct lttng_probe_desc *desc) |
ce5aef0b | 62 | { |
ce5aef0b | 63 | int i; |
48205d60 | 64 | size_t provider_name_len; |
ce5aef0b | 65 | |
48205d60 MD |
66 | provider_name_len = strnlen(desc->provider, |
67 | LTTNG_UST_SYM_NAME_LEN - 1); | |
68 | for (i = 0; i < desc->nr_events; i++) { | |
69 | if (strncmp(desc->event_desc[i]->name, | |
70 | desc->provider, | |
71 | provider_name_len)) | |
72 | return 0; /* provider mismatch */ | |
ce5aef0b | 73 | } |
48205d60 | 74 | return 1; |
ce5aef0b MD |
75 | } |
76 | ||
6715d7d1 MD |
77 | /* |
78 | * Called under ust lock. | |
79 | */ | |
80 | static | |
81 | void lttng_lazy_probe_register(struct lttng_probe_desc *desc) | |
ce5aef0b | 82 | { |
df854e41 | 83 | struct lttng_probe_desc *iter; |
ac69b35b | 84 | struct cds_list_head *probe_list; |
48205d60 | 85 | |
ce5aef0b | 86 | /* |
48205d60 MD |
87 | * Each provider enforce that every event name begins with the |
88 | * provider name. Check this in an assertion for extra | |
89 | * carefulness. This ensures we cannot have duplicate event | |
90 | * names across providers. | |
91 | */ | |
92 | assert(check_event_provider(desc)); | |
93 | ||
94 | /* | |
95 | * The provider ensures there are no duplicate event names. | |
96 | * Duplicated TRACEPOINT_EVENT event names would generate a | |
97 | * compile-time error due to duplicated symbol names. | |
ce5aef0b | 98 | */ |
df854e41 MD |
99 | |
100 | /* | |
101 | * We sort the providers by struct lttng_probe_desc pointer | |
102 | * address. | |
103 | */ | |
6715d7d1 | 104 | probe_list = &_probe_list; |
ac69b35b | 105 | cds_list_for_each_entry_reverse(iter, probe_list, head) { |
df854e41 MD |
106 | BUG_ON(iter == desc); /* Should never be in the list twice */ |
107 | if (iter < desc) { | |
108 | /* We belong to the location right after iter. */ | |
109 | cds_list_add(&desc->head, &iter->head); | |
110 | goto desc_added; | |
111 | } | |
112 | } | |
113 | /* We should be added at the head of the list */ | |
ac69b35b | 114 | cds_list_add(&desc->head, probe_list); |
df854e41 | 115 | desc_added: |
e81a53af MD |
116 | DBG("just registered probe %s containing %u events", |
117 | desc->provider, desc->nr_events); | |
6715d7d1 MD |
118 | } |
119 | ||
120 | /* | |
121 | * Called under ust lock. | |
122 | */ | |
123 | static | |
124 | void fixup_lazy_probes(void) | |
125 | { | |
126 | struct lttng_probe_desc *iter, *tmp; | |
5f733922 | 127 | int ret; |
6715d7d1 MD |
128 | |
129 | lazy_nesting++; | |
130 | cds_list_for_each_entry_safe(iter, tmp, | |
131 | &lazy_probe_init, lazy_init_head) { | |
132 | lttng_lazy_probe_register(iter); | |
133 | iter->lazy = 0; | |
134 | cds_list_del(&iter->lazy_init_head); | |
135 | } | |
5f733922 MD |
136 | ret = lttng_fix_pending_events(); |
137 | assert(!ret); | |
6715d7d1 MD |
138 | lazy_nesting--; |
139 | } | |
140 | ||
141 | /* | |
142 | * Called under ust lock. | |
143 | */ | |
144 | struct cds_list_head *lttng_get_probe_list_head(void) | |
145 | { | |
146 | if (!lazy_nesting && !cds_list_empty(&lazy_probe_init)) | |
147 | fixup_lazy_probes(); | |
148 | return &_probe_list; | |
149 | } | |
150 | ||
71d31690 MD |
151 | static |
152 | int check_provider_version(struct lttng_probe_desc *desc) | |
153 | { | |
154 | /* | |
155 | * Check tracepoint provider version compatibility. | |
156 | */ | |
157 | if (desc->major <= LTTNG_UST_PROVIDER_MAJOR) { | |
158 | DBG("Provider \"%s\" accepted, version %u.%u is compatible " | |
159 | "with LTTng UST provider version %u.%u.", | |
160 | desc->provider, desc->major, desc->minor, | |
161 | LTTNG_UST_PROVIDER_MAJOR, | |
162 | LTTNG_UST_PROVIDER_MINOR); | |
163 | if (desc->major < LTTNG_UST_PROVIDER_MAJOR) { | |
164 | DBG("However, some LTTng UST features might not be " | |
165 | "available for this provider unless it is " | |
166 | "recompiled against a more recent LTTng UST."); | |
167 | } | |
168 | return 1; /* accept */ | |
169 | } else { | |
170 | ERR("Provider \"%s\" rejected, version %u.%u is incompatible " | |
171 | "with LTTng UST provider version %u.%u. Please upgrade " | |
172 | "LTTng UST.", | |
173 | desc->provider, desc->major, desc->minor, | |
174 | LTTNG_UST_PROVIDER_MAJOR, | |
175 | LTTNG_UST_PROVIDER_MINOR); | |
176 | return 0; /* reject */ | |
177 | } | |
178 | } | |
179 | ||
180 | ||
6715d7d1 MD |
181 | int lttng_probe_register(struct lttng_probe_desc *desc) |
182 | { | |
183 | int ret = 0; | |
184 | ||
c362addf MD |
185 | lttng_ust_fixup_tls(); |
186 | ||
71d31690 MD |
187 | /* |
188 | * If version mismatch, don't register, but don't trigger assert | |
189 | * on caller. The version check just prints an error. | |
190 | */ | |
191 | if (!check_provider_version(desc)) | |
192 | return 0; | |
193 | ||
3327ac33 | 194 | ust_lock_nocheck(); |
6715d7d1 | 195 | |
6715d7d1 MD |
196 | cds_list_add(&desc->lazy_init_head, &lazy_probe_init); |
197 | desc->lazy = 1; | |
198 | DBG("adding probe %s containing %u events to lazy registration list", | |
199 | desc->provider, desc->nr_events); | |
200 | /* | |
201 | * If there is at least one active session, we need to register | |
202 | * the probe immediately, since we cannot delay event | |
203 | * registration because they are needed ASAP. | |
204 | */ | |
205 | if (lttng_session_active()) | |
206 | fixup_lazy_probes(); | |
0fdd0b89 | 207 | |
d8d2416d FD |
208 | lttng_fix_pending_event_notifiers(); |
209 | ||
17dfb34b | 210 | ust_unlock(); |
ce5aef0b MD |
211 | return ret; |
212 | } | |
ce5aef0b | 213 | |
7dd08bec | 214 | void lttng_probe_unregister(struct lttng_probe_desc *desc) |
ce5aef0b | 215 | { |
c362addf MD |
216 | lttng_ust_fixup_tls(); |
217 | ||
71d31690 MD |
218 | if (!check_provider_version(desc)) |
219 | return; | |
220 | ||
3327ac33 | 221 | ust_lock_nocheck(); |
6715d7d1 MD |
222 | if (!desc->lazy) |
223 | cds_list_del(&desc->head); | |
224 | else | |
225 | cds_list_del(&desc->lazy_init_head); | |
2c05c691 FD |
226 | |
227 | lttng_probe_provider_unregister_events(desc); | |
228 | DBG("just unregistered probes of provider %s", desc->provider); | |
229 | ||
17dfb34b | 230 | ust_unlock(); |
ce5aef0b | 231 | } |
ce5aef0b | 232 | |
7dd08bec | 233 | void lttng_probes_prune_event_list(struct lttng_ust_tracepoint_list *list) |
c8fcf224 MD |
234 | { |
235 | struct tp_list_entry *list_entry, *tmp; | |
236 | ||
237 | cds_list_for_each_entry_safe(list_entry, tmp, &list->head, head) { | |
238 | cds_list_del(&list_entry->head); | |
239 | free(list_entry); | |
240 | } | |
241 | } | |
242 | ||
243 | /* | |
244 | * called with UST lock held. | |
245 | */ | |
7dd08bec | 246 | int lttng_probes_get_event_list(struct lttng_ust_tracepoint_list *list) |
c8fcf224 MD |
247 | { |
248 | struct lttng_probe_desc *probe_desc; | |
249 | int i; | |
ac69b35b | 250 | struct cds_list_head *probe_list; |
c8fcf224 | 251 | |
ac69b35b | 252 | probe_list = lttng_get_probe_list_head(); |
c8fcf224 | 253 | CDS_INIT_LIST_HEAD(&list->head); |
ac69b35b | 254 | cds_list_for_each_entry(probe_desc, probe_list, head) { |
c8fcf224 MD |
255 | for (i = 0; i < probe_desc->nr_events; i++) { |
256 | struct tp_list_entry *list_entry; | |
257 | ||
258 | list_entry = zmalloc(sizeof(*list_entry)); | |
259 | if (!list_entry) | |
260 | goto err_nomem; | |
261 | cds_list_add(&list_entry->head, &list->head); | |
262 | strncpy(list_entry->tp.name, | |
263 | probe_desc->event_desc[i]->name, | |
264 | LTTNG_UST_SYM_NAME_LEN); | |
265 | list_entry->tp.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0'; | |
266 | if (!probe_desc->event_desc[i]->loglevel) { | |
882a56d7 | 267 | list_entry->tp.loglevel = TRACE_DEFAULT; |
c8fcf224 | 268 | } else { |
882a56d7 | 269 | list_entry->tp.loglevel = *(*probe_desc->event_desc[i]->loglevel); |
c8fcf224 MD |
270 | } |
271 | } | |
272 | } | |
273 | if (cds_list_empty(&list->head)) | |
274 | list->iter = NULL; | |
275 | else | |
276 | list->iter = | |
277 | cds_list_first_entry(&list->head, struct tp_list_entry, head); | |
278 | return 0; | |
279 | ||
280 | err_nomem: | |
7dd08bec | 281 | lttng_probes_prune_event_list(list); |
c8fcf224 MD |
282 | return -ENOMEM; |
283 | } | |
284 | ||
285 | /* | |
286 | * Return current iteration position, advance internal iterator to next. | |
287 | * Return NULL if end of list. | |
288 | */ | |
289 | struct lttng_ust_tracepoint_iter * | |
290 | lttng_ust_tracepoint_list_get_iter_next(struct lttng_ust_tracepoint_list *list) | |
291 | { | |
292 | struct tp_list_entry *entry; | |
293 | ||
294 | if (!list->iter) | |
295 | return NULL; | |
296 | entry = list->iter; | |
297 | if (entry->head.next == &list->head) | |
298 | list->iter = NULL; | |
299 | else | |
300 | list->iter = cds_list_entry(entry->head.next, | |
301 | struct tp_list_entry, head); | |
302 | return &entry->tp; | |
303 | } | |
1f18504e | 304 | |
7dd08bec | 305 | void lttng_probes_prune_field_list(struct lttng_ust_field_list *list) |
06d4f27e MD |
306 | { |
307 | struct tp_field_list_entry *list_entry, *tmp; | |
308 | ||
309 | cds_list_for_each_entry_safe(list_entry, tmp, &list->head, head) { | |
310 | cds_list_del(&list_entry->head); | |
311 | free(list_entry); | |
312 | } | |
313 | } | |
314 | ||
315 | /* | |
316 | * called with UST lock held. | |
317 | */ | |
7dd08bec | 318 | int lttng_probes_get_field_list(struct lttng_ust_field_list *list) |
06d4f27e MD |
319 | { |
320 | struct lttng_probe_desc *probe_desc; | |
321 | int i; | |
ac69b35b | 322 | struct cds_list_head *probe_list; |
06d4f27e | 323 | |
ac69b35b | 324 | probe_list = lttng_get_probe_list_head(); |
06d4f27e | 325 | CDS_INIT_LIST_HEAD(&list->head); |
ac69b35b | 326 | cds_list_for_each_entry(probe_desc, probe_list, head) { |
06d4f27e MD |
327 | for (i = 0; i < probe_desc->nr_events; i++) { |
328 | const struct lttng_event_desc *event_desc = | |
329 | probe_desc->event_desc[i]; | |
330 | int j; | |
331 | ||
26329f26 MD |
332 | if (event_desc->nr_fields == 0) { |
333 | /* Events without fields. */ | |
334 | struct tp_field_list_entry *list_entry; | |
335 | ||
336 | list_entry = zmalloc(sizeof(*list_entry)); | |
337 | if (!list_entry) | |
338 | goto err_nomem; | |
339 | cds_list_add(&list_entry->head, &list->head); | |
340 | strncpy(list_entry->field.event_name, | |
341 | event_desc->name, | |
342 | LTTNG_UST_SYM_NAME_LEN); | |
343 | list_entry->field.event_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0'; | |
344 | list_entry->field.field_name[0] = '\0'; | |
345 | list_entry->field.type = LTTNG_UST_FIELD_OTHER; | |
346 | if (!event_desc->loglevel) { | |
347 | list_entry->field.loglevel = TRACE_DEFAULT; | |
348 | } else { | |
349 | list_entry->field.loglevel = *(*event_desc->loglevel); | |
350 | } | |
351 | list_entry->field.nowrite = 1; | |
352 | } | |
353 | ||
06d4f27e MD |
354 | for (j = 0; j < event_desc->nr_fields; j++) { |
355 | const struct lttng_event_field *event_field = | |
356 | &event_desc->fields[j]; | |
357 | struct tp_field_list_entry *list_entry; | |
358 | ||
359 | list_entry = zmalloc(sizeof(*list_entry)); | |
360 | if (!list_entry) | |
361 | goto err_nomem; | |
362 | cds_list_add(&list_entry->head, &list->head); | |
363 | strncpy(list_entry->field.event_name, | |
364 | event_desc->name, | |
365 | LTTNG_UST_SYM_NAME_LEN); | |
366 | list_entry->field.event_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0'; | |
367 | strncpy(list_entry->field.field_name, | |
368 | event_field->name, | |
369 | LTTNG_UST_SYM_NAME_LEN); | |
370 | list_entry->field.field_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0'; | |
40003310 MD |
371 | switch (event_field->type.atype) { |
372 | case atype_integer: | |
373 | list_entry->field.type = LTTNG_UST_FIELD_INTEGER; | |
374 | break; | |
375 | case atype_string: | |
376 | list_entry->field.type = LTTNG_UST_FIELD_STRING; | |
377 | break; | |
378 | case atype_array: | |
218deb69 MD |
379 | if (event_field->type.u.legacy.array.elem_type.atype != atype_integer |
380 | || event_field->type.u.legacy.array.elem_type.u.basic.integer.encoding == lttng_encode_none) | |
381 | list_entry->field.type = LTTNG_UST_FIELD_OTHER; | |
382 | else | |
383 | list_entry->field.type = LTTNG_UST_FIELD_STRING; | |
384 | break; | |
385 | case atype_array_nestable: | |
386 | if (event_field->type.u.array_nestable.elem_type->atype != atype_integer | |
387 | || event_field->type.u.array_nestable.elem_type->u.integer.encoding == lttng_encode_none) | |
40003310 MD |
388 | list_entry->field.type = LTTNG_UST_FIELD_OTHER; |
389 | else | |
390 | list_entry->field.type = LTTNG_UST_FIELD_STRING; | |
391 | break; | |
392 | case atype_sequence: | |
218deb69 MD |
393 | if (event_field->type.u.legacy.sequence.elem_type.atype != atype_integer |
394 | || event_field->type.u.legacy.sequence.elem_type.u.basic.integer.encoding == lttng_encode_none) | |
395 | list_entry->field.type = LTTNG_UST_FIELD_OTHER; | |
396 | else | |
397 | list_entry->field.type = LTTNG_UST_FIELD_STRING; | |
398 | break; | |
399 | case atype_sequence_nestable: | |
400 | if (event_field->type.u.sequence_nestable.elem_type->atype != atype_integer | |
401 | || event_field->type.u.sequence_nestable.elem_type->u.integer.encoding == lttng_encode_none) | |
40003310 MD |
402 | list_entry->field.type = LTTNG_UST_FIELD_OTHER; |
403 | else | |
404 | list_entry->field.type = LTTNG_UST_FIELD_STRING; | |
405 | break; | |
406 | case atype_float: | |
407 | list_entry->field.type = LTTNG_UST_FIELD_FLOAT; | |
408 | break; | |
218deb69 MD |
409 | case atype_enum: /* Fall-through */ |
410 | case atype_enum_nestable: | |
40003310 MD |
411 | list_entry->field.type = LTTNG_UST_FIELD_ENUM; |
412 | break; | |
413 | default: | |
414 | list_entry->field.type = LTTNG_UST_FIELD_OTHER; | |
415 | } | |
06d4f27e MD |
416 | if (!event_desc->loglevel) { |
417 | list_entry->field.loglevel = TRACE_DEFAULT; | |
418 | } else { | |
419 | list_entry->field.loglevel = *(*event_desc->loglevel); | |
420 | } | |
180901e6 | 421 | list_entry->field.nowrite = event_field->nowrite; |
06d4f27e MD |
422 | } |
423 | } | |
424 | } | |
425 | if (cds_list_empty(&list->head)) | |
426 | list->iter = NULL; | |
427 | else | |
428 | list->iter = | |
429 | cds_list_first_entry(&list->head, | |
430 | struct tp_field_list_entry, head); | |
431 | return 0; | |
432 | ||
433 | err_nomem: | |
7dd08bec | 434 | lttng_probes_prune_field_list(list); |
06d4f27e MD |
435 | return -ENOMEM; |
436 | } | |
437 | ||
438 | /* | |
439 | * Return current iteration position, advance internal iterator to next. | |
440 | * Return NULL if end of list. | |
441 | */ | |
442 | struct lttng_ust_field_iter * | |
443 | lttng_ust_field_list_get_iter_next(struct lttng_ust_field_list *list) | |
444 | { | |
445 | struct tp_field_list_entry *entry; | |
446 | ||
447 | if (!list->iter) | |
448 | return NULL; | |
449 | entry = list->iter; | |
450 | if (entry->head.next == &list->head) | |
451 | list->iter = NULL; | |
452 | else | |
453 | list->iter = cds_list_entry(entry->head.next, | |
454 | struct tp_field_list_entry, head); | |
455 | return &entry->field; | |
456 | } |