Commit | Line | Data |
---|---|---|
8020ceb5 | 1 | /* |
e92f3e28 | 2 | * lttng-context.c |
8020ceb5 | 3 | * |
8173ec7c | 4 | * LTTng UST trace/channel/event context management. |
8020ceb5 | 5 | * |
e92f3e28 MD |
6 | * Copyright (C) 2011 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 | |
8020ceb5 MD |
21 | */ |
22 | ||
3fbec7dc | 23 | #define _LGPL_SOURCE |
4318ae1b MD |
24 | #include <lttng/ust-events.h> |
25 | #include <lttng/ust-tracer.h> | |
53569322 MD |
26 | #include <lttng/ust-context-provider.h> |
27 | #include <urcu-pointer.h> | |
a0a3bef9 | 28 | #include <usterr-signal-safe.h> |
35897f8b | 29 | #include <helper.h> |
b4051ad8 | 30 | #include <stddef.h> |
8d8a24c8 | 31 | #include <string.h> |
8173ec7c MD |
32 | #include <assert.h> |
33 | ||
51f804ec FD |
34 | #include "context-internal.h" |
35 | ||
77aa5901 MD |
36 | /* |
37 | * The filter implementation requires that two consecutive "get" for the | |
38 | * same context performed by the same thread return the same result. | |
39 | */ | |
40 | ||
8173ec7c MD |
41 | int lttng_find_context(struct lttng_ctx *ctx, const char *name) |
42 | { | |
43 | unsigned int i; | |
53569322 | 44 | const char *subname; |
8173ec7c | 45 | |
53569322 MD |
46 | if (strncmp(name, "$ctx.", strlen("$ctx.")) == 0) { |
47 | subname = name + strlen("$ctx."); | |
48 | } else { | |
49 | subname = name; | |
50 | } | |
8173ec7c MD |
51 | for (i = 0; i < ctx->nr_fields; i++) { |
52 | /* Skip allocated (but non-initialized) contexts */ | |
53 | if (!ctx->fields[i].event_field.name) | |
54 | continue; | |
53569322 | 55 | if (!strcmp(ctx->fields[i].event_field.name, subname)) |
8173ec7c MD |
56 | return 1; |
57 | } | |
58 | return 0; | |
59 | } | |
8020ceb5 | 60 | |
77aa5901 MD |
61 | int lttng_get_context_index(struct lttng_ctx *ctx, const char *name) |
62 | { | |
63 | unsigned int i; | |
53569322 | 64 | const char *subname; |
77aa5901 MD |
65 | |
66 | if (!ctx) | |
67 | return -1; | |
53569322 MD |
68 | if (strncmp(name, "$ctx.", strlen("$ctx.")) == 0) { |
69 | subname = name + strlen("$ctx."); | |
70 | } else { | |
71 | subname = name; | |
72 | } | |
77aa5901 MD |
73 | for (i = 0; i < ctx->nr_fields; i++) { |
74 | /* Skip allocated (but non-initialized) contexts */ | |
75 | if (!ctx->fields[i].event_field.name) | |
76 | continue; | |
53569322 | 77 | if (!strcmp(ctx->fields[i].event_field.name, subname)) |
77aa5901 MD |
78 | return i; |
79 | } | |
80 | return -1; | |
81 | } | |
82 | ||
53569322 MD |
83 | static int lttng_find_context_provider(struct lttng_ctx *ctx, const char *name) |
84 | { | |
85 | unsigned int i; | |
86 | ||
87 | for (i = 0; i < ctx->nr_fields; i++) { | |
88 | /* Skip allocated (but non-initialized) contexts */ | |
89 | if (!ctx->fields[i].event_field.name) | |
90 | continue; | |
91 | if (!strncmp(ctx->fields[i].event_field.name, name, | |
92 | strlen(name))) | |
93 | return 1; | |
94 | } | |
95 | return 0; | |
96 | } | |
97 | ||
a0a748b8 MD |
98 | /* |
99 | * Note: as we append context information, the pointer location may change. | |
100 | */ | |
8020ceb5 MD |
101 | struct lttng_ctx_field *lttng_append_context(struct lttng_ctx **ctx_p) |
102 | { | |
103 | struct lttng_ctx_field *field; | |
104 | struct lttng_ctx *ctx; | |
105 | ||
106 | if (!*ctx_p) { | |
8d8a24c8 | 107 | *ctx_p = zmalloc(sizeof(struct lttng_ctx)); |
8020ceb5 MD |
108 | if (!*ctx_p) |
109 | return NULL; | |
b2cc986a | 110 | (*ctx_p)->largest_align = 1; |
8020ceb5 MD |
111 | } |
112 | ctx = *ctx_p; | |
113 | if (ctx->nr_fields + 1 > ctx->allocated_fields) { | |
114 | struct lttng_ctx_field *new_fields; | |
115 | ||
116 | ctx->allocated_fields = max_t(size_t, 1, 2 * ctx->allocated_fields); | |
8d8a24c8 | 117 | new_fields = zmalloc(ctx->allocated_fields * sizeof(struct lttng_ctx_field)); |
8020ceb5 MD |
118 | if (!new_fields) |
119 | return NULL; | |
120 | if (ctx->fields) | |
121 | memcpy(new_fields, ctx->fields, sizeof(*ctx->fields) * ctx->nr_fields); | |
8d8a24c8 | 122 | free(ctx->fields); |
8020ceb5 MD |
123 | ctx->fields = new_fields; |
124 | } | |
125 | field = &ctx->fields[ctx->nr_fields]; | |
126 | ctx->nr_fields++; | |
127 | return field; | |
128 | } | |
8020ceb5 | 129 | |
53569322 MD |
130 | int lttng_context_add_rcu(struct lttng_ctx **ctx_p, |
131 | const struct lttng_ctx_field *f) | |
132 | { | |
133 | struct lttng_ctx *old_ctx = *ctx_p, *new_ctx = NULL; | |
134 | struct lttng_ctx_field *new_fields = NULL; | |
135 | struct lttng_ctx_field *nf; | |
136 | ||
137 | if (old_ctx) { | |
138 | new_ctx = zmalloc(sizeof(struct lttng_ctx)); | |
139 | if (!new_ctx) | |
140 | return -ENOMEM; | |
141 | *new_ctx = *old_ctx; | |
142 | new_fields = zmalloc(new_ctx->allocated_fields | |
143 | * sizeof(struct lttng_ctx_field)); | |
144 | if (!new_fields) { | |
145 | free(new_ctx); | |
146 | return -ENOMEM; | |
147 | } | |
148 | memcpy(new_fields, old_ctx->fields, | |
149 | sizeof(*old_ctx->fields) * old_ctx->nr_fields); | |
150 | new_ctx->fields = new_fields; | |
151 | } | |
152 | nf = lttng_append_context(&new_ctx); | |
153 | if (!nf) { | |
154 | free(new_fields); | |
155 | free(new_ctx); | |
156 | return -ENOMEM; | |
157 | } | |
158 | *nf = *f; | |
159 | lttng_context_update(new_ctx); | |
160 | rcu_assign_pointer(*ctx_p, new_ctx); | |
161 | synchronize_trace(); | |
162 | if (old_ctx) { | |
163 | free(old_ctx->fields); | |
164 | free(old_ctx); | |
165 | } | |
166 | return 0; | |
167 | } | |
168 | ||
b2cc986a MD |
169 | /* |
170 | * lttng_context_update() should be called at least once between context | |
171 | * modification and trace start. | |
172 | */ | |
173 | void lttng_context_update(struct lttng_ctx *ctx) | |
174 | { | |
175 | int i; | |
176 | size_t largest_align = 8; /* in bits */ | |
177 | ||
178 | for (i = 0; i < ctx->nr_fields; i++) { | |
179 | struct lttng_type *type; | |
180 | size_t field_align = 8; | |
181 | ||
182 | type = &ctx->fields[i].event_field.type; | |
183 | switch (type->atype) { | |
184 | case atype_integer: | |
218deb69 | 185 | field_align = type->u.integer.alignment; |
b2cc986a MD |
186 | break; |
187 | case atype_array: | |
188 | { | |
189 | struct lttng_basic_type *btype; | |
190 | ||
218deb69 | 191 | btype = &type->u.legacy.array.elem_type; |
b2cc986a MD |
192 | switch (btype->atype) { |
193 | case atype_integer: | |
194 | field_align = btype->u.basic.integer.alignment; | |
195 | break; | |
196 | case atype_string: | |
197 | break; | |
198 | ||
199 | case atype_array: | |
218deb69 | 200 | case atype_array_nestable: |
b2cc986a | 201 | case atype_sequence: |
218deb69 | 202 | case atype_sequence_nestable: |
b2cc986a MD |
203 | default: |
204 | WARN_ON_ONCE(1); | |
205 | break; | |
206 | } | |
207 | break; | |
208 | } | |
218deb69 MD |
209 | case atype_array_nestable: |
210 | { | |
211 | const struct lttng_type *nested_type; | |
212 | ||
213 | nested_type = type->u.array_nestable.elem_type; | |
214 | switch (nested_type->atype) { | |
215 | case atype_integer: | |
216 | field_align = nested_type->u.integer.alignment; | |
217 | break; | |
218 | case atype_string: | |
219 | break; | |
220 | ||
221 | case atype_array: | |
222 | case atype_array_nestable: | |
223 | case atype_sequence: | |
224 | case atype_sequence_nestable: | |
225 | default: | |
226 | WARN_ON_ONCE(1); | |
227 | break; | |
228 | } | |
229 | field_align = max_t(size_t, field_align, | |
230 | type->u.array_nestable.alignment); | |
231 | break; | |
232 | } | |
b2cc986a MD |
233 | case atype_sequence: |
234 | { | |
235 | struct lttng_basic_type *btype; | |
236 | ||
218deb69 | 237 | btype = &type->u.legacy.sequence.length_type; |
b2cc986a MD |
238 | switch (btype->atype) { |
239 | case atype_integer: | |
240 | field_align = btype->u.basic.integer.alignment; | |
241 | break; | |
242 | ||
243 | case atype_string: | |
244 | case atype_array: | |
218deb69 | 245 | case atype_array_nestable: |
b2cc986a | 246 | case atype_sequence: |
218deb69 | 247 | case atype_sequence_nestable: |
b2cc986a MD |
248 | default: |
249 | WARN_ON_ONCE(1); | |
250 | break; | |
251 | } | |
252 | ||
218deb69 | 253 | btype = &type->u.legacy.sequence.elem_type; |
b2cc986a MD |
254 | switch (btype->atype) { |
255 | case atype_integer: | |
256 | field_align = max_t(size_t, | |
257 | field_align, | |
258 | btype->u.basic.integer.alignment); | |
259 | break; | |
260 | ||
261 | case atype_string: | |
262 | break; | |
263 | ||
264 | case atype_array: | |
218deb69 MD |
265 | case atype_array_nestable: |
266 | case atype_sequence: | |
267 | case atype_sequence_nestable: | |
268 | default: | |
269 | WARN_ON_ONCE(1); | |
270 | break; | |
271 | } | |
272 | break; | |
273 | } | |
274 | case atype_sequence_nestable: | |
275 | { | |
276 | const struct lttng_type *nested_type; | |
277 | ||
278 | nested_type = type->u.sequence_nestable.elem_type; | |
279 | switch (nested_type->atype) { | |
280 | case atype_integer: | |
281 | field_align = nested_type->u.integer.alignment; | |
282 | break; | |
283 | ||
284 | case atype_string: | |
285 | break; | |
286 | ||
287 | case atype_array: | |
288 | case atype_array_nestable: | |
b2cc986a | 289 | case atype_sequence: |
218deb69 | 290 | case atype_sequence_nestable: |
b2cc986a MD |
291 | default: |
292 | WARN_ON_ONCE(1); | |
293 | break; | |
294 | } | |
218deb69 MD |
295 | field_align = max_t(size_t, field_align, |
296 | type->u.sequence_nestable.alignment); | |
b2cc986a MD |
297 | break; |
298 | } | |
299 | case atype_string: | |
300 | break; | |
53569322 MD |
301 | case atype_dynamic: |
302 | break; | |
b2cc986a | 303 | case atype_enum: |
218deb69 | 304 | case atype_enum_nestable: |
b2cc986a MD |
305 | default: |
306 | WARN_ON_ONCE(1); | |
307 | break; | |
308 | } | |
309 | largest_align = max_t(size_t, largest_align, field_align); | |
310 | } | |
311 | ctx->largest_align = largest_align >> 3; /* bits to bytes */ | |
312 | } | |
313 | ||
b13d13b1 MD |
314 | /* |
315 | * Remove last context field. | |
316 | */ | |
8020ceb5 MD |
317 | void lttng_remove_context_field(struct lttng_ctx **ctx_p, |
318 | struct lttng_ctx_field *field) | |
319 | { | |
320 | struct lttng_ctx *ctx; | |
321 | ||
322 | ctx = *ctx_p; | |
323 | ctx->nr_fields--; | |
8173ec7c | 324 | assert(&ctx->fields[ctx->nr_fields] == field); |
53569322 | 325 | assert(field->field_name == NULL); |
8020ceb5 MD |
326 | memset(&ctx->fields[ctx->nr_fields], 0, sizeof(struct lttng_ctx_field)); |
327 | } | |
8020ceb5 MD |
328 | |
329 | void lttng_destroy_context(struct lttng_ctx *ctx) | |
330 | { | |
331 | int i; | |
332 | ||
333 | if (!ctx) | |
334 | return; | |
335 | for (i = 0; i < ctx->nr_fields; i++) { | |
336 | if (ctx->fields[i].destroy) | |
337 | ctx->fields[i].destroy(&ctx->fields[i]); | |
53569322 | 338 | free(ctx->fields[i].field_name); |
8020ceb5 | 339 | } |
8d8a24c8 MD |
340 | free(ctx->fields); |
341 | free(ctx); | |
8020ceb5 | 342 | } |
a0a3bef9 | 343 | |
53569322 MD |
344 | /* |
345 | * Can be safely performed concurrently with tracing using the struct | |
346 | * lttng_ctx. Using RCU update. Needs to match RCU read-side handling of | |
347 | * contexts. | |
348 | * | |
349 | * This does not allow adding, removing, or changing typing of the | |
350 | * contexts, since this needs to stay invariant for metadata. However, | |
351 | * it allows updating the handlers associated with all contexts matching | |
352 | * a provider (by name) while tracing is using it, in a way that ensures | |
353 | * a single RCU read-side critical section see either all old, or all | |
354 | * new handlers. | |
355 | */ | |
356 | int lttng_ust_context_set_provider_rcu(struct lttng_ctx **_ctx, | |
357 | const char *name, | |
358 | size_t (*get_size)(struct lttng_ctx_field *field, size_t offset), | |
359 | void (*record)(struct lttng_ctx_field *field, | |
360 | struct lttng_ust_lib_ring_buffer_ctx *ctx, | |
361 | struct lttng_channel *chan), | |
362 | void (*get_value)(struct lttng_ctx_field *field, | |
363 | struct lttng_ctx_value *value)) | |
364 | { | |
365 | int i, ret; | |
366 | struct lttng_ctx *ctx = *_ctx, *new_ctx; | |
367 | struct lttng_ctx_field *new_fields; | |
368 | ||
369 | if (!ctx || !lttng_find_context_provider(ctx, name)) | |
370 | return 0; | |
371 | /* | |
372 | * We have at least one instance of context for the provider. | |
373 | */ | |
374 | new_ctx = zmalloc(sizeof(*new_ctx)); | |
375 | if (!new_ctx) | |
376 | return -ENOMEM; | |
377 | *new_ctx = *ctx; | |
378 | new_fields = zmalloc(sizeof(*new_fields) * ctx->allocated_fields); | |
379 | if (!new_fields) { | |
380 | ret = -ENOMEM; | |
381 | goto field_error; | |
382 | } | |
383 | memcpy(new_fields, ctx->fields, | |
384 | sizeof(*new_fields) * ctx->allocated_fields); | |
385 | for (i = 0; i < ctx->nr_fields; i++) { | |
386 | if (strncmp(new_fields[i].event_field.name, | |
387 | name, strlen(name)) != 0) | |
388 | continue; | |
389 | new_fields[i].get_size = get_size; | |
390 | new_fields[i].record = record; | |
391 | new_fields[i].get_value = get_value; | |
392 | } | |
393 | new_ctx->fields = new_fields; | |
394 | rcu_assign_pointer(*_ctx, new_ctx); | |
395 | synchronize_trace(); | |
396 | free(ctx->fields); | |
397 | free(ctx); | |
398 | return 0; | |
399 | ||
400 | field_error: | |
401 | free(new_ctx); | |
402 | return ret; | |
403 | } | |
404 | ||
51f804ec | 405 | int lttng_context_init_all(struct lttng_ctx **ctx) |
a0a3bef9 MD |
406 | { |
407 | int ret; | |
408 | ||
53569322 | 409 | ret = lttng_add_pthread_id_to_ctx(ctx); |
a0a3bef9 MD |
410 | if (ret) { |
411 | WARN("Cannot add context lttng_add_pthread_id_to_ctx"); | |
53569322 | 412 | goto error; |
a0a3bef9 | 413 | } |
53569322 | 414 | ret = lttng_add_vtid_to_ctx(ctx); |
a0a3bef9 MD |
415 | if (ret) { |
416 | WARN("Cannot add context lttng_add_vtid_to_ctx"); | |
53569322 | 417 | goto error; |
a0a3bef9 | 418 | } |
53569322 | 419 | ret = lttng_add_vpid_to_ctx(ctx); |
a0a3bef9 MD |
420 | if (ret) { |
421 | WARN("Cannot add context lttng_add_vpid_to_ctx"); | |
53569322 | 422 | goto error; |
a0a3bef9 | 423 | } |
53569322 | 424 | ret = lttng_add_procname_to_ctx(ctx); |
a0a3bef9 MD |
425 | if (ret) { |
426 | WARN("Cannot add context lttng_add_procname_to_ctx"); | |
53569322 | 427 | goto error; |
a0a3bef9 | 428 | } |
53569322 | 429 | ret = lttng_add_cpu_id_to_ctx(ctx); |
c7ea8487 MD |
430 | if (ret) { |
431 | WARN("Cannot add context lttng_add_cpu_id_to_ctx"); | |
53569322 | 432 | goto error; |
c7ea8487 | 433 | } |
735bef47 MJ |
434 | ret = lttng_add_cgroup_ns_to_ctx(ctx); |
435 | if (ret) { | |
436 | WARN("Cannot add context lttng_add_cgroup_ns_to_ctx"); | |
437 | goto error; | |
438 | } | |
439 | ret = lttng_add_ipc_ns_to_ctx(ctx); | |
440 | if (ret) { | |
441 | WARN("Cannot add context lttng_add_ipc_ns_to_ctx"); | |
442 | goto error; | |
443 | } | |
444 | ret = lttng_add_mnt_ns_to_ctx(ctx); | |
445 | if (ret) { | |
446 | WARN("Cannot add context lttng_add_mnt_ns_to_ctx"); | |
447 | goto error; | |
448 | } | |
449 | ret = lttng_add_net_ns_to_ctx(ctx); | |
450 | if (ret) { | |
451 | WARN("Cannot add context lttng_add_net_ns_to_ctx"); | |
452 | goto error; | |
453 | } | |
454 | ret = lttng_add_pid_ns_to_ctx(ctx); | |
455 | if (ret) { | |
456 | WARN("Cannot add context lttng_add_pid_ns_to_ctx"); | |
457 | goto error; | |
458 | } | |
cefef7a7 MJ |
459 | ret = lttng_add_time_ns_to_ctx(ctx); |
460 | if (ret) { | |
461 | WARN("Cannot add context lttng_add_time_ns_to_ctx"); | |
462 | goto error; | |
463 | } | |
735bef47 MJ |
464 | ret = lttng_add_user_ns_to_ctx(ctx); |
465 | if (ret) { | |
466 | WARN("Cannot add context lttng_add_user_ns_to_ctx"); | |
467 | goto error; | |
468 | } | |
469 | ret = lttng_add_uts_ns_to_ctx(ctx); | |
470 | if (ret) { | |
471 | WARN("Cannot add context lttng_add_uts_ns_to_ctx"); | |
472 | goto error; | |
473 | } | |
fca2f191 MJ |
474 | ret = lttng_add_vuid_to_ctx(ctx); |
475 | if (ret) { | |
476 | WARN("Cannot add context lttng_add_vuid_to_ctx"); | |
477 | goto error; | |
478 | } | |
479 | ret = lttng_add_veuid_to_ctx(ctx); | |
480 | if (ret) { | |
481 | WARN("Cannot add context lttng_add_veuid_to_ctx"); | |
482 | goto error; | |
483 | } | |
484 | ret = lttng_add_vsuid_to_ctx(ctx); | |
485 | if (ret) { | |
486 | WARN("Cannot add context lttng_add_vsuid_to_ctx"); | |
487 | goto error; | |
488 | } | |
489 | ret = lttng_add_vgid_to_ctx(ctx); | |
490 | if (ret) { | |
491 | WARN("Cannot add context lttng_add_vgid_to_ctx"); | |
492 | goto error; | |
493 | } | |
494 | ret = lttng_add_vegid_to_ctx(ctx); | |
495 | if (ret) { | |
496 | WARN("Cannot add context lttng_add_vegid_to_ctx"); | |
497 | goto error; | |
498 | } | |
499 | ret = lttng_add_vsgid_to_ctx(ctx); | |
500 | if (ret) { | |
501 | WARN("Cannot add context lttng_add_vsgid_to_ctx"); | |
502 | goto error; | |
503 | } | |
53569322 MD |
504 | lttng_context_update(*ctx); |
505 | return 0; | |
a0a3bef9 | 506 | |
53569322 MD |
507 | error: |
508 | lttng_destroy_context(*ctx); | |
509 | return ret; | |
a0a3bef9 | 510 | } |
4a1f7569 MD |
511 | |
512 | /* For backward compatibility. Leave those exported symbols in place. */ | |
513 | struct lttng_ctx *lttng_static_ctx; | |
514 | ||
515 | void lttng_context_init(void) | |
516 | { | |
517 | } | |
518 | ||
519 | void lttng_context_exit(void) | |
520 | { | |
521 | } | |
51f804ec FD |
522 | |
523 | int lttng_session_context_init(struct lttng_ctx **ctx) | |
524 | { | |
525 | return 0; | |
526 | } |