Fix: pass private data to context callbacks
[lttng-ust.git] / liblttng-ust / lttng-probes.c
CommitLineData
ce5aef0b 1/*
c0c0989a 2 * SPDX-License-Identifier: LGPL-2.1-only
ce5aef0b 3 *
c0c0989a 4 * Copyright 2010-2012 (C) Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
e92f3e28 5 *
c0c0989a 6 * Holds LTTng probes registry.
ce5aef0b
MD
7 */
8
3fbec7dc 9#define _LGPL_SOURCE
8d8a24c8
MD
10#include <string.h>
11#include <errno.h>
12#include <urcu/list.h>
1f18504e 13#include <urcu/hlist.h>
4318ae1b 14#include <lttng/ust-events.h>
902e1379 15#include <lttng/tracepoint.h>
d8de1354 16#include "tracepoint-internal.h"
a3bb4b27 17#include <assert.h>
864a1eda 18#include <ust-helper.h>
48740cab 19#include <ctype.h>
ce5aef0b 20
7dd08bec 21#include "lttng-tracer-core.h"
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22#include "jhash.h"
23#include "error.h"
d8d2416d 24#include "ust-events-internal.h"
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25
26/*
17dfb34b 27 * probe list is protected by ust_lock()/ust_unlock().
8165c8da 28 */
ac69b35b 29static CDS_LIST_HEAD(_probe_list);
e58095ef 30
6715d7d1
MD
31/*
32 * List of probes registered by not yet processed.
33 */
34static CDS_LIST_HEAD(lazy_probe_init);
df854e41 35
6715d7d1
MD
36/*
37 * lazy_nesting counter ensures we don't trigger lazy probe registration
38 * fixup while we are performing the fixup. It is protected by the ust
39 * mutex.
40 */
41static int lazy_nesting;
df854e41 42
6715d7d1 43/*
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MD
44 * Validate that each event within the probe provider refers to the
45 * right probe, and that the resulting name is not too long.
6715d7d1 46 */
ce5aef0b 47static
4e48b5d2 48bool check_event_provider(const struct lttng_ust_probe_desc *probe_desc)
ce5aef0b 49{
ce5aef0b 50 int i;
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51
52 for (i = 0; i < probe_desc->nr_events; i++) {
53 const struct lttng_ust_event_desc *event_desc = probe_desc->event_desc[i];
54
55 if (event_desc->probe_desc != probe_desc) {
56 ERR("Error registering probe provider '%s'. Event '%s:%s' refers to the wrong provider descriptor.",
57 probe_desc->provider_name, probe_desc->provider_name, event_desc->event_name);
58 return false; /* provider mismatch */
59 }
60 if (!lttng_ust_validate_event_name(event_desc)) {
61 ERR("Error registering probe provider '%s'. Event '%s:%s' name is too long.",
62 probe_desc->provider_name, probe_desc->provider_name, event_desc->event_name);
63 return false; /* provider mismatch */
64 }
ce5aef0b 65 }
5b4c6da4 66 return true;
ce5aef0b
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67}
68
6715d7d1
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69/*
70 * Called under ust lock.
71 */
72static
4e48b5d2 73void lttng_lazy_probe_register(struct lttng_ust_registered_probe *reg_probe)
ce5aef0b 74{
4e48b5d2 75 struct lttng_ust_registered_probe *iter;
ac69b35b 76 struct cds_list_head *probe_list;
48205d60 77
48205d60
MD
78 /*
79 * The provider ensures there are no duplicate event names.
80 * Duplicated TRACEPOINT_EVENT event names would generate a
81 * compile-time error due to duplicated symbol names.
ce5aef0b 82 */
df854e41
MD
83
84 /*
dc11f93f 85 * We sort the providers by struct lttng_ust_probe_desc pointer
df854e41
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86 * address.
87 */
6715d7d1 88 probe_list = &_probe_list;
ac69b35b 89 cds_list_for_each_entry_reverse(iter, probe_list, head) {
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MD
90 BUG_ON(iter == reg_probe); /* Should never be in the list twice */
91 if (iter < reg_probe) {
df854e41 92 /* We belong to the location right after iter. */
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93 cds_list_add(&reg_probe->head, &iter->head);
94 goto probe_added;
df854e41
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95 }
96 }
97 /* We should be added at the head of the list */
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98 cds_list_add(&reg_probe->head, probe_list);
99probe_added:
e81a53af 100 DBG("just registered probe %s containing %u events",
4e48b5d2 101 reg_probe->desc->provider_name, reg_probe->desc->nr_events);
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102}
103
104/*
105 * Called under ust lock.
106 */
107static
108void fixup_lazy_probes(void)
109{
4e48b5d2 110 struct lttng_ust_registered_probe *iter, *tmp;
5f733922 111 int ret;
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112
113 lazy_nesting++;
114 cds_list_for_each_entry_safe(iter, tmp,
115 &lazy_probe_init, lazy_init_head) {
116 lttng_lazy_probe_register(iter);
117 iter->lazy = 0;
118 cds_list_del(&iter->lazy_init_head);
119 }
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120 ret = lttng_fix_pending_events();
121 assert(!ret);
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122 lazy_nesting--;
123}
124
125/*
126 * Called under ust lock.
127 */
128struct cds_list_head *lttng_get_probe_list_head(void)
129{
130 if (!lazy_nesting && !cds_list_empty(&lazy_probe_init))
131 fixup_lazy_probes();
132 return &_probe_list;
133}
134
71d31690 135static
4e48b5d2 136int check_provider_version(const struct lttng_ust_probe_desc *desc)
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137{
138 /*
139 * Check tracepoint provider version compatibility.
140 */
141 if (desc->major <= LTTNG_UST_PROVIDER_MAJOR) {
142 DBG("Provider \"%s\" accepted, version %u.%u is compatible "
143 "with LTTng UST provider version %u.%u.",
5b4c6da4 144 desc->provider_name, desc->major, desc->minor,
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145 LTTNG_UST_PROVIDER_MAJOR,
146 LTTNG_UST_PROVIDER_MINOR);
147 if (desc->major < LTTNG_UST_PROVIDER_MAJOR) {
148 DBG("However, some LTTng UST features might not be "
149 "available for this provider unless it is "
150 "recompiled against a more recent LTTng UST.");
151 }
152 return 1; /* accept */
153 } else {
154 ERR("Provider \"%s\" rejected, version %u.%u is incompatible "
155 "with LTTng UST provider version %u.%u. Please upgrade "
156 "LTTng UST.",
5b4c6da4 157 desc->provider_name, desc->major, desc->minor,
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158 LTTNG_UST_PROVIDER_MAJOR,
159 LTTNG_UST_PROVIDER_MINOR);
160 return 0; /* reject */
161 }
162}
163
4e48b5d2 164struct lttng_ust_registered_probe *lttng_ust_probe_register(const struct lttng_ust_probe_desc *desc)
6715d7d1 165{
4e48b5d2 166 struct lttng_ust_registered_probe *reg_probe = NULL;
6715d7d1 167
c362addf
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168 lttng_ust_fixup_tls();
169
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170 /*
171 * If version mismatch, don't register, but don't trigger assert
172 * on caller. The version check just prints an error.
173 */
174 if (!check_provider_version(desc))
4e48b5d2 175 return NULL;
5b4c6da4 176 if (!check_event_provider(desc))
4e48b5d2 177 return NULL;
71d31690 178
3327ac33 179 ust_lock_nocheck();
6715d7d1 180
4e48b5d2
MD
181 reg_probe = zmalloc(sizeof(struct lttng_ust_registered_probe));
182 if (!reg_probe)
183 goto end;
184 reg_probe->desc = desc;
185 cds_list_add(&reg_probe->lazy_init_head, &lazy_probe_init);
186 reg_probe->lazy = 1;
187
6715d7d1 188 DBG("adding probe %s containing %u events to lazy registration list",
5b4c6da4 189 desc->provider_name, desc->nr_events);
6715d7d1
MD
190 /*
191 * If there is at least one active session, we need to register
192 * the probe immediately, since we cannot delay event
193 * registration because they are needed ASAP.
194 */
195 if (lttng_session_active())
196 fixup_lazy_probes();
0fdd0b89 197
d8d2416d 198 lttng_fix_pending_event_notifiers();
4e48b5d2 199end:
17dfb34b 200 ust_unlock();
4e48b5d2 201 return reg_probe;
ce5aef0b 202}
ce5aef0b 203
4e48b5d2 204void lttng_ust_probe_unregister(struct lttng_ust_registered_probe *reg_probe)
ce5aef0b 205{
c362addf
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206 lttng_ust_fixup_tls();
207
4e48b5d2
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208 if (!reg_probe)
209 return;
210 if (!check_provider_version(reg_probe->desc))
71d31690
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211 return;
212
3327ac33 213 ust_lock_nocheck();
4e48b5d2
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214 if (!reg_probe->lazy)
215 cds_list_del(&reg_probe->head);
6715d7d1 216 else
4e48b5d2 217 cds_list_del(&reg_probe->lazy_init_head);
2c05c691 218
4e48b5d2
MD
219 lttng_probe_provider_unregister_events(reg_probe->desc);
220 DBG("just unregistered probes of provider %s", reg_probe->desc->provider_name);
17dfb34b 221 ust_unlock();
4e48b5d2 222 free(reg_probe);
ce5aef0b 223}
ce5aef0b 224
7dd08bec 225void lttng_probes_prune_event_list(struct lttng_ust_tracepoint_list *list)
c8fcf224
MD
226{
227 struct tp_list_entry *list_entry, *tmp;
228
229 cds_list_for_each_entry_safe(list_entry, tmp, &list->head, head) {
230 cds_list_del(&list_entry->head);
231 free(list_entry);
232 }
233}
234
235/*
236 * called with UST lock held.
237 */
7dd08bec 238int lttng_probes_get_event_list(struct lttng_ust_tracepoint_list *list)
c8fcf224 239{
4e48b5d2 240 struct lttng_ust_registered_probe *reg_probe;
ac69b35b 241 struct cds_list_head *probe_list;
4e48b5d2 242 int i;
c8fcf224 243
ac69b35b 244 probe_list = lttng_get_probe_list_head();
c8fcf224 245 CDS_INIT_LIST_HEAD(&list->head);
4e48b5d2
MD
246 cds_list_for_each_entry(reg_probe, probe_list, head) {
247 const struct lttng_ust_probe_desc *probe_desc = reg_probe->desc;
248
c8fcf224 249 for (i = 0; i < probe_desc->nr_events; i++) {
5b4c6da4
MD
250 const struct lttng_ust_event_desc *event_desc =
251 probe_desc->event_desc[i];
c8fcf224
MD
252 struct tp_list_entry *list_entry;
253
5b4c6da4
MD
254 /* Skip event if name is too long. */
255 if (!lttng_ust_validate_event_name(event_desc))
256 continue;
c8fcf224
MD
257 list_entry = zmalloc(sizeof(*list_entry));
258 if (!list_entry)
259 goto err_nomem;
260 cds_list_add(&list_entry->head, &list->head);
5b4c6da4
MD
261 lttng_ust_format_event_name(event_desc, list_entry->tp.name);
262 if (!event_desc->loglevel) {
882a56d7 263 list_entry->tp.loglevel = TRACE_DEFAULT;
c8fcf224 264 } else {
5b4c6da4 265 list_entry->tp.loglevel = *(*event_desc->loglevel);
c8fcf224
MD
266 }
267 }
268 }
269 if (cds_list_empty(&list->head))
270 list->iter = NULL;
271 else
272 list->iter =
273 cds_list_first_entry(&list->head, struct tp_list_entry, head);
274 return 0;
275
276err_nomem:
7dd08bec 277 lttng_probes_prune_event_list(list);
c8fcf224
MD
278 return -ENOMEM;
279}
280
281/*
282 * Return current iteration position, advance internal iterator to next.
283 * Return NULL if end of list.
284 */
fd17d7ce 285struct lttng_ust_abi_tracepoint_iter *
c8fcf224
MD
286 lttng_ust_tracepoint_list_get_iter_next(struct lttng_ust_tracepoint_list *list)
287{
288 struct tp_list_entry *entry;
289
290 if (!list->iter)
291 return NULL;
292 entry = list->iter;
293 if (entry->head.next == &list->head)
294 list->iter = NULL;
295 else
296 list->iter = cds_list_entry(entry->head.next,
297 struct tp_list_entry, head);
298 return &entry->tp;
299}
1f18504e 300
7dd08bec 301void lttng_probes_prune_field_list(struct lttng_ust_field_list *list)
06d4f27e
MD
302{
303 struct tp_field_list_entry *list_entry, *tmp;
304
305 cds_list_for_each_entry_safe(list_entry, tmp, &list->head, head) {
306 cds_list_del(&list_entry->head);
307 free(list_entry);
308 }
309}
310
311/*
312 * called with UST lock held.
313 */
7dd08bec 314int lttng_probes_get_field_list(struct lttng_ust_field_list *list)
06d4f27e 315{
4e48b5d2 316 struct lttng_ust_registered_probe *reg_probe;
ac69b35b 317 struct cds_list_head *probe_list;
4e48b5d2 318 int i;
06d4f27e 319
ac69b35b 320 probe_list = lttng_get_probe_list_head();
06d4f27e 321 CDS_INIT_LIST_HEAD(&list->head);
4e48b5d2
MD
322 cds_list_for_each_entry(reg_probe, probe_list, head) {
323 const struct lttng_ust_probe_desc *probe_desc = reg_probe->desc;
324
06d4f27e 325 for (i = 0; i < probe_desc->nr_events; i++) {
dc11f93f 326 const struct lttng_ust_event_desc *event_desc =
06d4f27e
MD
327 probe_desc->event_desc[i];
328 int j;
329
26329f26
MD
330 if (event_desc->nr_fields == 0) {
331 /* Events without fields. */
332 struct tp_field_list_entry *list_entry;
333
5b4c6da4
MD
334 /* Skip event if name is too long. */
335 if (!lttng_ust_validate_event_name(event_desc))
336 continue;
26329f26
MD
337 list_entry = zmalloc(sizeof(*list_entry));
338 if (!list_entry)
339 goto err_nomem;
340 cds_list_add(&list_entry->head, &list->head);
5b4c6da4 341 lttng_ust_format_event_name(event_desc, list_entry->field.event_name);
26329f26 342 list_entry->field.field_name[0] = '\0';
fd17d7ce 343 list_entry->field.type = LTTNG_UST_ABI_FIELD_OTHER;
26329f26
MD
344 if (!event_desc->loglevel) {
345 list_entry->field.loglevel = TRACE_DEFAULT;
346 } else {
347 list_entry->field.loglevel = *(*event_desc->loglevel);
348 }
349 list_entry->field.nowrite = 1;
350 }
351
06d4f27e 352 for (j = 0; j < event_desc->nr_fields; j++) {
25cff019
MD
353 const struct lttng_ust_event_field *event_field =
354 event_desc->fields[j];
06d4f27e
MD
355 struct tp_field_list_entry *list_entry;
356
5b4c6da4
MD
357 /* Skip event if name is too long. */
358 if (!lttng_ust_validate_event_name(event_desc))
359 continue;
06d4f27e
MD
360 list_entry = zmalloc(sizeof(*list_entry));
361 if (!list_entry)
362 goto err_nomem;
363 cds_list_add(&list_entry->head, &list->head);
5b4c6da4 364 lttng_ust_format_event_name(event_desc, list_entry->field.event_name);
06d4f27e
MD
365 strncpy(list_entry->field.field_name,
366 event_field->name,
fd17d7ce
MD
367 LTTNG_UST_ABI_SYM_NAME_LEN);
368 list_entry->field.field_name[LTTNG_UST_ABI_SYM_NAME_LEN - 1] = '\0';
a084756d
MD
369 switch (event_field->type->type) {
370 case lttng_ust_type_integer:
fd17d7ce 371 list_entry->field.type = LTTNG_UST_ABI_FIELD_INTEGER;
40003310 372 break;
a084756d 373 case lttng_ust_type_string:
fd17d7ce 374 list_entry->field.type = LTTNG_UST_ABI_FIELD_STRING;
40003310 375 break;
a084756d
MD
376 case lttng_ust_type_array:
377 if (lttng_ust_get_type_array(event_field->type)->encoding == lttng_ust_string_encoding_none)
fd17d7ce 378 list_entry->field.type = LTTNG_UST_ABI_FIELD_OTHER;
40003310 379 else
fd17d7ce 380 list_entry->field.type = LTTNG_UST_ABI_FIELD_STRING;
40003310 381 break;
a084756d
MD
382 case lttng_ust_type_sequence:
383 if (lttng_ust_get_type_sequence(event_field->type)->encoding == lttng_ust_string_encoding_none)
fd17d7ce 384 list_entry->field.type = LTTNG_UST_ABI_FIELD_OTHER;
40003310 385 else
fd17d7ce 386 list_entry->field.type = LTTNG_UST_ABI_FIELD_STRING;
40003310 387 break;
a084756d 388 case lttng_ust_type_float:
fd17d7ce 389 list_entry->field.type = LTTNG_UST_ABI_FIELD_FLOAT;
40003310 390 break;
a084756d 391 case lttng_ust_type_enum:
fd17d7ce 392 list_entry->field.type = LTTNG_UST_ABI_FIELD_ENUM;
40003310
MD
393 break;
394 default:
fd17d7ce 395 list_entry->field.type = LTTNG_UST_ABI_FIELD_OTHER;
40003310 396 }
06d4f27e
MD
397 if (!event_desc->loglevel) {
398 list_entry->field.loglevel = TRACE_DEFAULT;
399 } else {
400 list_entry->field.loglevel = *(*event_desc->loglevel);
401 }
180901e6 402 list_entry->field.nowrite = event_field->nowrite;
06d4f27e
MD
403 }
404 }
405 }
406 if (cds_list_empty(&list->head))
407 list->iter = NULL;
408 else
409 list->iter =
410 cds_list_first_entry(&list->head,
411 struct tp_field_list_entry, head);
412 return 0;
413
414err_nomem:
7dd08bec 415 lttng_probes_prune_field_list(list);
06d4f27e
MD
416 return -ENOMEM;
417}
418
419/*
420 * Return current iteration position, advance internal iterator to next.
421 * Return NULL if end of list.
422 */
fd17d7ce 423struct lttng_ust_abi_field_iter *
06d4f27e
MD
424 lttng_ust_field_list_get_iter_next(struct lttng_ust_field_list *list)
425{
426 struct tp_field_list_entry *entry;
427
428 if (!list->iter)
429 return NULL;
430 entry = list->iter;
431 if (entry->head.next == &list->head)
432 list->iter = NULL;
433 else
434 list->iter = cds_list_entry(entry->head.next,
435 struct tp_field_list_entry, head);
436 return &entry->field;
437}
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