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d8d2416d | 1 | /* |
c0c0989a | 2 | * SPDX-License-Identifier: LGPL-2.1-only |
d8d2416d FD |
3 | * |
4 | * Copyright (C) 2020 Francis Deslauriers <francis.deslauriers@efficios.com> | |
d8d2416d FD |
5 | */ |
6 | ||
7 | #define _LGPL_SOURCE | |
8 | ||
b9f82a28 | 9 | #include <assert.h> |
d8d2416d | 10 | #include <errno.h> |
9af5d97a MJ |
11 | #include <limits.h> |
12 | ||
f03092d7 | 13 | #include <lttng/ust-endian.h> |
9d315d6d | 14 | #include "common/logging.h" |
a2e4d05e | 15 | #include <urcu/rculist.h> |
d8d2416d | 16 | |
4b4a1337 | 17 | #include "lttng-tracer-core.h" |
36c52fff | 18 | #include "lib/lttng-ust/events.h" |
c3ba99c2 | 19 | #include "common/msgpack/msgpack.h" |
b9f82a28 | 20 | #include "lttng-bytecode.h" |
9d315d6d | 21 | #include "common/patient.h" |
d8d2416d | 22 | |
d37ecb3f FD |
23 | /* |
24 | * We want this write to be atomic AND non-blocking, meaning that we | |
25 | * want to write either everything OR nothing. | |
26 | * According to `pipe(7)`, writes that are less than `PIPE_BUF` bytes must be | |
27 | * atomic, so we bound the capture buffer size to the `PIPE_BUF` minus the size | |
28 | * of the notification struct we are sending alongside the capture buffer. | |
29 | */ | |
30 | #define CAPTURE_BUFFER_SIZE \ | |
fd17d7ce | 31 | (PIPE_BUF - sizeof(struct lttng_ust_abi_event_notifier_notification) - 1) |
d37ecb3f | 32 | |
65c955a5 MD |
33 | #define MSG_WRITE_NIL_LEN 1 |
34 | ||
d37ecb3f FD |
35 | struct lttng_event_notifier_notification { |
36 | int notification_fd; | |
37 | uint64_t event_notifier_token; | |
38 | uint8_t capture_buf[CAPTURE_BUFFER_SIZE]; | |
39 | struct lttng_msgpack_writer writer; | |
40 | bool has_captures; | |
41 | }; | |
42 | ||
b9f82a28 | 43 | static |
c651e872 | 44 | int capture_enum(struct lttng_msgpack_writer *writer, |
b9f82a28 FD |
45 | struct lttng_interpreter_output *output) |
46 | { | |
c651e872 | 47 | int ret; |
b9f82a28 | 48 | |
c651e872 MD |
49 | ret = lttng_msgpack_begin_map(writer, 2); |
50 | if (ret) { | |
51 | goto end; | |
52 | } | |
53 | ret = lttng_msgpack_write_str(writer, "type"); | |
54 | if (ret) { | |
55 | goto end; | |
56 | } | |
57 | ret = lttng_msgpack_write_str(writer, "enum"); | |
58 | if (ret) { | |
59 | goto end; | |
60 | } | |
61 | ret = lttng_msgpack_write_str(writer, "value"); | |
62 | if (ret) { | |
63 | goto end; | |
64 | } | |
b9f82a28 FD |
65 | |
66 | switch (output->type) { | |
67 | case LTTNG_INTERPRETER_TYPE_SIGNED_ENUM: | |
c651e872 MD |
68 | ret = lttng_msgpack_write_signed_integer(writer, output->u.s); |
69 | if (ret) { | |
70 | goto end; | |
71 | } | |
b9f82a28 FD |
72 | break; |
73 | case LTTNG_INTERPRETER_TYPE_UNSIGNED_ENUM: | |
c651e872 MD |
74 | ret = lttng_msgpack_write_signed_integer(writer, output->u.u); |
75 | if (ret) { | |
76 | goto end; | |
77 | } | |
b9f82a28 FD |
78 | break; |
79 | default: | |
c651e872 MD |
80 | CRIT("Unknown enum output type\n"); |
81 | ret = -1; | |
82 | goto end; | |
b9f82a28 FD |
83 | } |
84 | ||
c651e872 MD |
85 | ret = lttng_msgpack_end_map(writer); |
86 | end: | |
87 | return ret; | |
b9f82a28 FD |
88 | } |
89 | ||
90 | static | |
91 | int64_t capture_sequence_element_signed(uint8_t *ptr, | |
4e48b5d2 | 92 | const struct lttng_ust_type_integer *integer_type) |
b9f82a28 FD |
93 | { |
94 | int64_t value; | |
a084756d MD |
95 | unsigned int size = integer_type->size; |
96 | bool byte_order_reversed = integer_type->reverse_byte_order; | |
b9f82a28 FD |
97 | |
98 | switch (size) { | |
99 | case 8: | |
100 | value = *ptr; | |
101 | break; | |
102 | case 16: | |
103 | { | |
104 | int16_t tmp; | |
105 | tmp = *(int16_t *) ptr; | |
106 | if (byte_order_reversed) | |
baa8acf3 | 107 | tmp = lttng_ust_bswap_16(tmp); |
b9f82a28 FD |
108 | |
109 | value = tmp; | |
110 | break; | |
111 | } | |
112 | case 32: | |
113 | { | |
114 | int32_t tmp; | |
115 | tmp = *(int32_t *) ptr; | |
116 | if (byte_order_reversed) | |
baa8acf3 | 117 | tmp = lttng_ust_bswap_32(tmp); |
b9f82a28 FD |
118 | |
119 | value = tmp; | |
120 | break; | |
121 | } | |
122 | case 64: | |
123 | { | |
124 | int64_t tmp; | |
125 | tmp = *(int64_t *) ptr; | |
126 | if (byte_order_reversed) | |
baa8acf3 | 127 | tmp = lttng_ust_bswap_64(tmp); |
b9f82a28 FD |
128 | |
129 | value = tmp; | |
130 | break; | |
131 | } | |
132 | default: | |
c651e872 MD |
133 | CRIT("Unknown sequence element size\n"); |
134 | value = 0; | |
b9f82a28 FD |
135 | } |
136 | ||
137 | return value; | |
138 | } | |
139 | ||
140 | static | |
141 | uint64_t capture_sequence_element_unsigned(uint8_t *ptr, | |
4e48b5d2 | 142 | const struct lttng_ust_type_integer *integer_type) |
b9f82a28 FD |
143 | { |
144 | uint64_t value; | |
a084756d MD |
145 | unsigned int size = integer_type->size; |
146 | bool byte_order_reversed = integer_type->reverse_byte_order; | |
b9f82a28 FD |
147 | |
148 | switch (size) { | |
149 | case 8: | |
150 | value = *ptr; | |
151 | break; | |
152 | case 16: | |
153 | { | |
154 | uint16_t tmp; | |
155 | tmp = *(uint16_t *) ptr; | |
156 | if (byte_order_reversed) | |
baa8acf3 | 157 | tmp = lttng_ust_bswap_16(tmp); |
b9f82a28 FD |
158 | |
159 | value = tmp; | |
160 | break; | |
161 | } | |
162 | case 32: | |
163 | { | |
164 | uint32_t tmp; | |
165 | tmp = *(uint32_t *) ptr; | |
166 | if (byte_order_reversed) | |
baa8acf3 | 167 | tmp = lttng_ust_bswap_32(tmp); |
b9f82a28 FD |
168 | |
169 | value = tmp; | |
170 | break; | |
171 | } | |
172 | case 64: | |
173 | { | |
174 | uint64_t tmp; | |
175 | tmp = *(uint64_t *) ptr; | |
176 | if (byte_order_reversed) | |
baa8acf3 | 177 | tmp = lttng_ust_bswap_64(tmp); |
b9f82a28 FD |
178 | |
179 | value = tmp; | |
180 | break; | |
181 | } | |
182 | default: | |
c651e872 MD |
183 | CRIT("Unknown sequence element size\n"); |
184 | value = 0; | |
b9f82a28 FD |
185 | } |
186 | ||
187 | return value; | |
188 | } | |
189 | ||
b9f82a28 | 190 | static |
c651e872 | 191 | int capture_sequence(struct lttng_msgpack_writer *writer, |
b9f82a28 FD |
192 | struct lttng_interpreter_output *output) |
193 | { | |
4e48b5d2 MD |
194 | const struct lttng_ust_type_integer *integer_type; |
195 | const struct lttng_ust_type_common *nested_type; | |
b9f82a28 FD |
196 | uint8_t *ptr; |
197 | bool signedness; | |
c651e872 | 198 | int i, ret; |
b9f82a28 | 199 | |
c651e872 MD |
200 | ret = lttng_msgpack_begin_array(writer, output->u.sequence.nr_elem); |
201 | if (ret) { | |
202 | goto end; | |
203 | } | |
b9f82a28 FD |
204 | ptr = (uint8_t *) output->u.sequence.ptr; |
205 | nested_type = output->u.sequence.nested_type; | |
a084756d MD |
206 | switch (nested_type->type) { |
207 | case lttng_ust_type_integer: | |
208 | integer_type = lttng_ust_get_type_integer(nested_type); | |
b9f82a28 | 209 | break; |
a084756d | 210 | case lttng_ust_type_enum: |
b9f82a28 | 211 | /* Treat enumeration as an integer. */ |
a084756d | 212 | integer_type = lttng_ust_get_type_integer(lttng_ust_get_type_enum(nested_type)->container_type); |
b9f82a28 FD |
213 | break; |
214 | default: | |
c651e872 MD |
215 | CRIT("Capture of array of non-integer are not supported\n"); |
216 | ret = -1; | |
217 | goto end; | |
b9f82a28 FD |
218 | } |
219 | signedness = integer_type->signedness; | |
220 | for (i = 0; i < output->u.sequence.nr_elem; i++) { | |
221 | if (signedness) { | |
c651e872 | 222 | ret = lttng_msgpack_write_signed_integer(writer, |
b9f82a28 FD |
223 | capture_sequence_element_signed(ptr, integer_type)); |
224 | } else { | |
c651e872 | 225 | ret = lttng_msgpack_write_unsigned_integer(writer, |
b9f82a28 FD |
226 | capture_sequence_element_unsigned(ptr, integer_type)); |
227 | } | |
c651e872 MD |
228 | if (ret) { |
229 | goto end; | |
230 | } | |
b9f82a28 FD |
231 | |
232 | /* | |
233 | * We assume that alignment is smaller or equal to the size. | |
234 | * This currently holds true but if it changes in the future, | |
2fbda51c | 235 | * we will want to change the pointer arithmetic below to |
b9f82a28 FD |
236 | * take into account that the next element might be further |
237 | * away. | |
238 | */ | |
239 | assert(integer_type->alignment <= integer_type->size); | |
240 | ||
241 | /* Size is in number of bits. */ | |
242 | ptr += (integer_type->size / CHAR_BIT) ; | |
243 | } | |
244 | ||
c651e872 MD |
245 | ret = lttng_msgpack_end_array(writer); |
246 | end: | |
247 | return ret; | |
b9f82a28 FD |
248 | } |
249 | ||
d37ecb3f | 250 | static |
c651e872 | 251 | int notification_init(struct lttng_event_notifier_notification *notif, |
cda77256 | 252 | const struct lttng_ust_event_notifier *event_notifier) |
d8d2416d | 253 | { |
d37ecb3f | 254 | struct lttng_msgpack_writer *writer = ¬if->writer; |
c651e872 | 255 | int ret = 0; |
d37ecb3f | 256 | |
115db533 MD |
257 | notif->event_notifier_token = event_notifier->priv->parent.user_token; |
258 | notif->notification_fd = event_notifier->priv->group->notification_fd; | |
d37ecb3f FD |
259 | notif->has_captures = false; |
260 | ||
115db533 | 261 | if (event_notifier->priv->num_captures > 0) { |
d37ecb3f FD |
262 | lttng_msgpack_writer_init(writer, notif->capture_buf, |
263 | CAPTURE_BUFFER_SIZE); | |
264 | ||
c651e872 MD |
265 | ret = lttng_msgpack_begin_array(writer, event_notifier->priv->num_captures); |
266 | if (ret) { | |
267 | goto end; | |
268 | } | |
d37ecb3f FD |
269 | notif->has_captures = true; |
270 | } | |
c651e872 MD |
271 | end: |
272 | return ret; | |
d37ecb3f FD |
273 | } |
274 | ||
275 | static | |
c651e872 | 276 | int notification_append_capture( |
d37ecb3f FD |
277 | struct lttng_event_notifier_notification *notif, |
278 | struct lttng_interpreter_output *output) | |
279 | { | |
280 | struct lttng_msgpack_writer *writer = ¬if->writer; | |
c651e872 | 281 | int ret; |
d37ecb3f FD |
282 | |
283 | switch (output->type) { | |
284 | case LTTNG_INTERPRETER_TYPE_S64: | |
c651e872 | 285 | ret = lttng_msgpack_write_signed_integer(writer, output->u.s); |
d37ecb3f FD |
286 | break; |
287 | case LTTNG_INTERPRETER_TYPE_U64: | |
c651e872 | 288 | ret = lttng_msgpack_write_unsigned_integer(writer, output->u.u); |
d37ecb3f FD |
289 | break; |
290 | case LTTNG_INTERPRETER_TYPE_DOUBLE: | |
c651e872 | 291 | ret = lttng_msgpack_write_double(writer, output->u.d); |
d37ecb3f FD |
292 | break; |
293 | case LTTNG_INTERPRETER_TYPE_STRING: | |
c651e872 | 294 | ret = lttng_msgpack_write_str(writer, output->u.str.str); |
d37ecb3f FD |
295 | break; |
296 | case LTTNG_INTERPRETER_TYPE_SEQUENCE: | |
c651e872 | 297 | ret = capture_sequence(writer, output); |
d37ecb3f FD |
298 | break; |
299 | case LTTNG_INTERPRETER_TYPE_SIGNED_ENUM: | |
300 | case LTTNG_INTERPRETER_TYPE_UNSIGNED_ENUM: | |
c651e872 | 301 | ret = capture_enum(writer, output); |
d37ecb3f FD |
302 | break; |
303 | default: | |
c651e872 MD |
304 | CRIT("Unknown capture output type\n"); |
305 | ret = -1; | |
d37ecb3f | 306 | } |
c651e872 | 307 | return ret; |
d37ecb3f FD |
308 | } |
309 | ||
310 | static | |
c651e872 | 311 | int notification_append_empty_capture( |
d37ecb3f FD |
312 | struct lttng_event_notifier_notification *notif) |
313 | { | |
c651e872 | 314 | return lttng_msgpack_write_nil(¬if->writer); |
d37ecb3f FD |
315 | } |
316 | ||
cda77256 | 317 | static void record_error(const struct lttng_ust_event_notifier *event_notifier) |
6566528b FD |
318 | { |
319 | struct lttng_event_notifier_group *event_notifier_group = | |
115db533 | 320 | event_notifier->priv->group; |
b187bcd5 | 321 | struct lttng_ust_channel_counter *error_counter; |
6566528b FD |
322 | size_t dimension_index[1]; |
323 | int ret; | |
324 | ||
33f43caa MD |
325 | error_counter = CMM_LOAD_SHARED(event_notifier_group->error_counter); |
326 | /* | |
327 | * load-acquire paired with store-release orders creation of the | |
328 | * error counter and setting error_counter_len before the | |
329 | * error_counter is used. | |
330 | * Currently a full memory barrier is used, which could be | |
331 | * turned into acquire-release barriers. | |
332 | */ | |
333 | cmm_smp_mb(); | |
c30ad764 | 334 | /* This group may not have an error counter attached to it. */ |
33f43caa | 335 | if (!error_counter) |
c30ad764 MD |
336 | return; |
337 | ||
115db533 | 338 | dimension_index[0] = event_notifier->priv->error_counter_index; |
b187bcd5 MD |
339 | ret = event_notifier_group->error_counter->ops->priv->counter_add( |
340 | error_counter, dimension_index, 1); | |
6566528b FD |
341 | if (ret) |
342 | WARN_ON_ONCE(1); | |
343 | } | |
344 | ||
d37ecb3f | 345 | static |
6566528b | 346 | void notification_send(struct lttng_event_notifier_notification *notif, |
cda77256 | 347 | const struct lttng_ust_event_notifier *event_notifier) |
d37ecb3f FD |
348 | { |
349 | ssize_t ret; | |
350 | size_t content_len; | |
351 | int iovec_count = 1; | |
fd17d7ce | 352 | struct lttng_ust_abi_event_notifier_notification ust_notif = {0}; |
d37ecb3f FD |
353 | struct iovec iov[2]; |
354 | ||
355 | assert(notif); | |
356 | ||
115db533 | 357 | ust_notif.token = event_notifier->priv->parent.user_token; |
d37ecb3f | 358 | |
d8d2416d | 359 | /* |
d37ecb3f FD |
360 | * Prepare sending the notification from multiple buffers using an |
361 | * array of `struct iovec`. The first buffer of the vector is | |
362 | * notification structure itself and is always present. | |
d8d2416d | 363 | */ |
d37ecb3f FD |
364 | iov[0].iov_base = &ust_notif; |
365 | iov[0].iov_len = sizeof(ust_notif); | |
366 | ||
367 | if (notif->has_captures) { | |
368 | /* | |
369 | * If captures were requested, the second buffer of the array | |
370 | * is the capture buffer. | |
371 | */ | |
372 | assert(notif->writer.buffer); | |
373 | content_len = notif->writer.write_pos - notif->writer.buffer; | |
d8d2416d | 374 | |
d37ecb3f | 375 | assert(content_len > 0 && content_len <= CAPTURE_BUFFER_SIZE); |
d8d2416d | 376 | |
d37ecb3f FD |
377 | iov[1].iov_base = notif->capture_buf; |
378 | iov[1].iov_len = content_len; | |
379 | ||
380 | iovec_count++; | |
381 | } else { | |
382 | content_len = 0; | |
383 | } | |
384 | ||
385 | /* | |
386 | * Update the capture buffer size so that receiver of the buffer will | |
387 | * know how much to expect. | |
388 | */ | |
389 | ust_notif.capture_buf_size = content_len; | |
d8d2416d | 390 | |
d37ecb3f | 391 | /* Send all the buffers. */ |
516d12da | 392 | ret = ust_patient_writev(notif->notification_fd, iov, iovec_count); |
d8d2416d FD |
393 | if (ret == -1) { |
394 | if (errno == EAGAIN) { | |
6566528b FD |
395 | record_error(event_notifier); |
396 | DBG("Cannot send event_notifier notification without blocking: %s", | |
d8d2416d FD |
397 | strerror(errno)); |
398 | } else { | |
399 | DBG("Error to sending event notifier notification: %s", | |
400 | strerror(errno)); | |
401 | abort(); | |
402 | } | |
403 | } | |
404 | } | |
d37ecb3f | 405 | |
65c955a5 MD |
406 | /* |
407 | * Validate that the buffer has enough room to hold empty capture fields. | |
408 | */ | |
409 | static | |
410 | bool validate_buffer_len(struct lttng_event_notifier_notification *notif, size_t captures_left) | |
411 | { | |
412 | if (notif->writer.end_write_pos - notif->writer.write_pos < MSG_WRITE_NIL_LEN * captures_left) | |
413 | return false; | |
414 | return true; | |
415 | } | |
416 | ||
6566528b | 417 | void lttng_event_notifier_notification_send( |
cda77256 | 418 | const struct lttng_ust_event_notifier *event_notifier, |
a2e4d05e | 419 | const char *stack_data, |
b2e37d27 | 420 | struct lttng_ust_probe_ctx *probe_ctx, |
a2e4d05e | 421 | struct lttng_ust_notification_ctx *notif_ctx) |
d37ecb3f FD |
422 | { |
423 | /* | |
424 | * This function is called from the probe, we must do dynamic | |
425 | * allocation in this context. | |
426 | */ | |
427 | struct lttng_event_notifier_notification notif = {0}; | |
65c955a5 | 428 | size_t captures_left; |
d37ecb3f | 429 | |
65c955a5 MD |
430 | if (notification_init(¬if, event_notifier)) |
431 | goto error; | |
432 | ||
433 | captures_left = event_notifier->priv->num_captures; | |
434 | if (!validate_buffer_len(¬if, captures_left)) | |
435 | goto error; | |
d37ecb3f | 436 | |
a2e4d05e | 437 | if (caa_unlikely(notif_ctx->eval_capture)) { |
5469a374 | 438 | struct lttng_ust_bytecode_runtime *capture_bc_runtime; |
d37ecb3f FD |
439 | |
440 | /* | |
441 | * Iterate over all the capture bytecodes. If the interpreter | |
442 | * functions returns successfully, append the value of the | |
443 | * `output` parameter to the capture buffer. If the interpreter | |
444 | * fails, append an empty capture to the buffer. | |
445 | */ | |
a2e4d05e MD |
446 | cds_list_for_each_entry_rcu(capture_bc_runtime, |
447 | &event_notifier->priv->capture_bytecode_runtime_head, node) { | |
d37ecb3f | 448 | struct lttng_interpreter_output output; |
c651e872 | 449 | uint8_t *save_pos; |
65c955a5 | 450 | int ret = -1; |
d37ecb3f | 451 | |
c651e872 | 452 | lttng_msgpack_save_writer_pos(¬if.writer, &save_pos); |
22c30e27 | 453 | if (capture_bc_runtime->interpreter_func(capture_bc_runtime, |
b2e37d27 | 454 | stack_data, probe_ctx, &output) == LTTNG_UST_BYTECODE_INTERPRETER_OK) |
c651e872 | 455 | ret = notification_append_capture(¬if, &output); |
65c955a5 | 456 | if (ret || !validate_buffer_len(¬if, captures_left)) { |
c651e872 | 457 | /* |
65c955a5 MD |
458 | * On append capture error or if the generated |
459 | * buffer data would not leave enough room to | |
460 | * write empty capture fields for the remaining | |
461 | * fields, skip the field capture by restoring | |
462 | * the msgpack writer position and writing an | |
463 | * empty capture field. | |
c651e872 MD |
464 | */ |
465 | lttng_msgpack_restore_writer_pos(¬if.writer, save_pos); | |
65c955a5 MD |
466 | ret = notification_append_empty_capture(¬if); |
467 | if (ret) | |
468 | CRIT("Not enough space for empty capture field\n"); | |
c651e872 | 469 | } |
d37ecb3f FD |
470 | } |
471 | } | |
472 | ||
65c955a5 MD |
473 | if (notif.has_captures && lttng_msgpack_end_array(¬if.writer)) |
474 | goto error; | |
475 | ||
d37ecb3f FD |
476 | /* |
477 | * Send the notification (including the capture buffer) to the | |
478 | * sessiond. | |
479 | */ | |
6566528b | 480 | notification_send(¬if, event_notifier); |
65c955a5 MD |
481 | return; |
482 | ||
483 | error: | |
484 | record_error(event_notifier); | |
c651e872 | 485 | return; |
d37ecb3f | 486 | } |