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250c663f MD |
1 | /* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1) |
2 | * | |
3 | * lttng-ring-buffer-event-notifier-client.h | |
4 | * | |
5 | * LTTng lib ring buffer event notifier client template. | |
6 | * | |
7 | * Copyright (C) 2010-2020 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
8 | */ | |
9 | ||
99d223ad | 10 | #include <linux/limits.h> |
250c663f MD |
11 | #include <linux/module.h> |
12 | #include <linux/types.h> | |
13 | #include <wrapper/vmalloc.h> /* for wrapper_vmalloc_sync_mappings() */ | |
99d223ad | 14 | #include <lttng/abi.h> |
250c663f | 15 | #include <lttng/events.h> |
17f90b04 | 16 | #include <lttng/events-internal.h> |
250c663f | 17 | #include <lttng/tracer.h> |
236233f7 | 18 | #include <wrapper/limits.h> |
250c663f MD |
19 | |
20 | static struct lttng_transport lttng_relay_transport; | |
21 | ||
22 | struct event_notifier_packet_header { | |
23 | uint8_t header_end[0]; | |
24 | }; | |
25 | ||
26 | struct event_notifier_record_header { | |
99d223ad | 27 | uint32_t payload_len; /* in bytes */ |
250c663f MD |
28 | uint8_t header_end[0]; /* End of header */ |
29 | }; | |
30 | ||
31 | static const struct lib_ring_buffer_config client_config; | |
32 | ||
33 | static inline | |
34 | u64 lib_ring_buffer_clock_read(struct channel *chan) | |
35 | { | |
36 | return 0; | |
37 | } | |
38 | ||
39 | static inline | |
40 | size_t record_header_size(const struct lib_ring_buffer_config *config, | |
41 | struct channel *chan, size_t offset, | |
42 | size_t *pre_header_padding, | |
43 | struct lib_ring_buffer_ctx *ctx, | |
44 | void *client_ctx) | |
45 | { | |
99d223ad FD |
46 | size_t orig_offset = offset; |
47 | size_t padding; | |
48 | ||
49 | padding = lib_ring_buffer_align(offset, lttng_alignof(uint32_t)); | |
50 | offset += padding; | |
51 | ||
52 | offset += sizeof(uint32_t); | |
53 | ||
54 | *pre_header_padding = padding; | |
55 | ||
56 | return offset - orig_offset; | |
250c663f MD |
57 | } |
58 | ||
59 | #include <ringbuffer/api.h> | |
60 | ||
61 | static u64 client_ring_buffer_clock_read(struct channel *chan) | |
62 | { | |
63 | return 0; | |
64 | } | |
65 | ||
66 | static | |
67 | size_t client_record_header_size(const struct lib_ring_buffer_config *config, | |
68 | struct channel *chan, size_t offset, | |
69 | size_t *pre_header_padding, | |
70 | struct lib_ring_buffer_ctx *ctx, | |
71 | void *client_ctx) | |
72 | { | |
99d223ad FD |
73 | return record_header_size(config, chan, offset, |
74 | pre_header_padding, ctx, client_ctx); | |
250c663f MD |
75 | } |
76 | ||
77 | /** | |
78 | * client_packet_header_size - called on buffer-switch to a new sub-buffer | |
79 | * | |
80 | * Return header size without padding after the structure. Don't use packed | |
81 | * structure because gcc generates inefficient code on some architectures | |
82 | * (powerpc, mips..) | |
83 | */ | |
84 | static size_t client_packet_header_size(void) | |
85 | { | |
86 | return offsetof(struct event_notifier_packet_header, header_end); | |
87 | } | |
88 | ||
89 | static void client_buffer_begin(struct lib_ring_buffer *buf, u64 tsc, | |
90 | unsigned int subbuf_idx) | |
91 | { | |
92 | } | |
93 | ||
94 | /* | |
95 | * offset is assumed to never be 0 here : never deliver a completely empty | |
96 | * subbuffer. data_size is between 1 and subbuf_size. | |
97 | */ | |
98 | static void client_buffer_end(struct lib_ring_buffer *buf, u64 tsc, | |
99 | unsigned int subbuf_idx, unsigned long data_size) | |
100 | { | |
101 | } | |
102 | ||
103 | static int client_buffer_create(struct lib_ring_buffer *buf, void *priv, | |
104 | int cpu, const char *name) | |
105 | { | |
106 | return 0; | |
107 | } | |
108 | ||
109 | static void client_buffer_finalize(struct lib_ring_buffer *buf, void *priv, int cpu) | |
110 | { | |
111 | } | |
112 | ||
113 | static int client_timestamp_begin(const struct lib_ring_buffer_config *config, | |
114 | struct lib_ring_buffer *buf, uint64_t *timestamp_begin) | |
115 | { | |
116 | return -ENOSYS; | |
117 | } | |
118 | ||
119 | static int client_timestamp_end(const struct lib_ring_buffer_config *config, | |
120 | struct lib_ring_buffer *bufb, | |
121 | uint64_t *timestamp_end) | |
122 | { | |
123 | return -ENOSYS; | |
124 | } | |
125 | ||
126 | static int client_events_discarded(const struct lib_ring_buffer_config *config, | |
127 | struct lib_ring_buffer *bufb, | |
128 | uint64_t *events_discarded) | |
129 | { | |
130 | return -ENOSYS; | |
131 | } | |
132 | ||
133 | static int client_current_timestamp(const struct lib_ring_buffer_config *config, | |
134 | struct lib_ring_buffer *bufb, | |
135 | uint64_t *ts) | |
136 | { | |
137 | return -ENOSYS; | |
138 | } | |
139 | ||
140 | static int client_content_size(const struct lib_ring_buffer_config *config, | |
141 | struct lib_ring_buffer *bufb, | |
142 | uint64_t *content_size) | |
143 | { | |
144 | return -ENOSYS; | |
145 | } | |
146 | ||
147 | static int client_packet_size(const struct lib_ring_buffer_config *config, | |
148 | struct lib_ring_buffer *bufb, | |
149 | uint64_t *packet_size) | |
150 | { | |
151 | return -ENOSYS; | |
152 | } | |
153 | ||
154 | static int client_stream_id(const struct lib_ring_buffer_config *config, | |
155 | struct lib_ring_buffer *bufb, | |
156 | uint64_t *stream_id) | |
157 | { | |
158 | return -ENOSYS; | |
159 | } | |
160 | ||
161 | static int client_sequence_number(const struct lib_ring_buffer_config *config, | |
162 | struct lib_ring_buffer *bufb, | |
163 | uint64_t *seq) | |
164 | { | |
165 | return -ENOSYS; | |
166 | } | |
167 | ||
168 | static | |
169 | int client_instance_id(const struct lib_ring_buffer_config *config, | |
170 | struct lib_ring_buffer *bufb, | |
171 | uint64_t *id) | |
172 | { | |
173 | return -ENOSYS; | |
174 | } | |
175 | ||
176 | static void client_record_get(const struct lib_ring_buffer_config *config, | |
177 | struct channel *chan, struct lib_ring_buffer *buf, | |
178 | size_t offset, size_t *header_len, | |
179 | size_t *payload_len, u64 *timestamp) | |
180 | { | |
181 | struct event_notifier_record_header header; | |
182 | int ret; | |
183 | ||
184 | ret = lib_ring_buffer_read(&buf->backend, offset, &header, | |
185 | offsetof(struct event_notifier_record_header, header_end)); | |
186 | CHAN_WARN_ON(chan, ret != offsetof(struct event_notifier_record_header, header_end)); | |
187 | *header_len = offsetof(struct event_notifier_record_header, header_end); | |
99d223ad | 188 | *payload_len = header.payload_len; |
250c663f MD |
189 | *timestamp = 0; |
190 | } | |
191 | ||
192 | static const struct lib_ring_buffer_config client_config = { | |
193 | .cb.ring_buffer_clock_read = client_ring_buffer_clock_read, | |
194 | .cb.record_header_size = client_record_header_size, | |
195 | .cb.subbuffer_header_size = client_packet_header_size, | |
196 | .cb.buffer_begin = client_buffer_begin, | |
197 | .cb.buffer_end = client_buffer_end, | |
198 | .cb.buffer_create = client_buffer_create, | |
199 | .cb.buffer_finalize = client_buffer_finalize, | |
200 | .cb.record_get = client_record_get, | |
201 | ||
202 | .tsc_bits = 0, | |
203 | .alloc = RING_BUFFER_ALLOC_GLOBAL, | |
204 | .sync = RING_BUFFER_SYNC_GLOBAL, | |
205 | .mode = RING_BUFFER_MODE_TEMPLATE, | |
206 | .backend = RING_BUFFER_PAGE, | |
207 | .output = RING_BUFFER_OUTPUT_TEMPLATE, | |
208 | .oops = RING_BUFFER_OOPS_CONSISTENCY, | |
209 | .ipi = RING_BUFFER_NO_IPI_BARRIER, | |
210 | .wakeup = RING_BUFFER_WAKEUP_BY_WRITER, | |
211 | }; | |
212 | ||
213 | static | |
214 | void release_priv_ops(void *priv_ops) | |
215 | { | |
216 | module_put(THIS_MODULE); | |
217 | } | |
218 | ||
219 | static | |
220 | void lttng_channel_destroy(struct channel *chan) | |
221 | { | |
222 | channel_destroy(chan); | |
223 | } | |
224 | ||
225 | static | |
226 | struct channel *_channel_create(const char *name, | |
227 | void *priv, void *buf_addr, | |
228 | size_t subbuf_size, size_t num_subbuf, | |
229 | unsigned int switch_timer_interval, | |
230 | unsigned int read_timer_interval) | |
231 | { | |
232 | struct lttng_event_notifier_group *event_notifier_group = priv; | |
233 | struct channel *chan; | |
234 | ||
235 | chan = channel_create(&client_config, name, | |
236 | event_notifier_group, buf_addr, | |
237 | subbuf_size, num_subbuf, switch_timer_interval, | |
238 | read_timer_interval); | |
239 | if (chan) { | |
240 | /* | |
241 | * Ensure this module is not unloaded before we finish | |
242 | * using lttng_relay_transport.ops. | |
243 | */ | |
244 | if (!try_module_get(THIS_MODULE)) { | |
245 | printk(KERN_WARNING "LTTng: Can't lock event_notifier transport module.\n"); | |
246 | goto error; | |
247 | } | |
248 | chan->backend.priv_ops = <tng_relay_transport.ops; | |
249 | chan->backend.release_priv_ops = release_priv_ops; | |
250 | } | |
251 | return chan; | |
252 | ||
253 | error: | |
254 | lttng_channel_destroy(chan); | |
255 | return NULL; | |
256 | } | |
257 | ||
258 | static | |
259 | struct lib_ring_buffer *lttng_buffer_read_open(struct channel *chan) | |
260 | { | |
261 | struct lib_ring_buffer *buf; | |
262 | ||
263 | buf = channel_get_ring_buffer(&client_config, chan, 0); | |
264 | if (!lib_ring_buffer_open_read(buf)) | |
265 | return buf; | |
266 | return NULL; | |
267 | } | |
268 | ||
269 | static | |
270 | int lttng_buffer_has_read_closed_stream(struct channel *chan) | |
271 | { | |
272 | struct lib_ring_buffer *buf; | |
273 | int cpu; | |
274 | ||
275 | for_each_channel_cpu(cpu, chan) { | |
276 | buf = channel_get_ring_buffer(&client_config, chan, cpu); | |
277 | if (!atomic_long_read(&buf->active_readers)) | |
278 | return 1; | |
279 | } | |
280 | return 0; | |
281 | } | |
282 | ||
283 | static | |
284 | void lttng_buffer_read_close(struct lib_ring_buffer *buf) | |
285 | { | |
286 | lib_ring_buffer_release_read(buf); | |
287 | } | |
288 | ||
99d223ad FD |
289 | static |
290 | void lttng_write_event_notifier_header(const struct lib_ring_buffer_config *config, | |
291 | struct lib_ring_buffer_ctx *ctx) | |
292 | { | |
293 | uint32_t data_size; | |
294 | ||
295 | WARN_ON_ONCE(ctx->data_size > U32_MAX); | |
296 | ||
297 | data_size = (uint32_t) ctx->data_size; | |
298 | ||
299 | lib_ring_buffer_write(config, ctx, &data_size, sizeof(data_size)); | |
300 | ||
301 | lib_ring_buffer_align_ctx(ctx, ctx->largest_align); | |
302 | } | |
303 | ||
250c663f | 304 | static |
cefd899f | 305 | int lttng_event_reserve(struct lib_ring_buffer_ctx *ctx) |
250c663f | 306 | { |
c7d9db61 | 307 | struct channel *chan = ctx->client_priv; |
250c663f MD |
308 | int ret; |
309 | ||
c7d9db61 MD |
310 | memset(&ctx->priv, 0, sizeof(ctx->priv)); |
311 | ctx->priv.chan = chan; | |
312 | ||
250c663f MD |
313 | ret = lib_ring_buffer_reserve(&client_config, ctx, NULL); |
314 | if (ret) | |
315 | return ret; | |
316 | lib_ring_buffer_backend_get_pages(&client_config, ctx, | |
c7d9db61 | 317 | &ctx->priv.backend_pages); |
99d223ad FD |
318 | |
319 | lttng_write_event_notifier_header(&client_config, ctx); | |
250c663f MD |
320 | return 0; |
321 | } | |
322 | ||
323 | static | |
324 | void lttng_event_commit(struct lib_ring_buffer_ctx *ctx) | |
325 | { | |
326 | lib_ring_buffer_commit(&client_config, ctx); | |
327 | } | |
328 | ||
329 | static | |
330 | void lttng_event_write(struct lib_ring_buffer_ctx *ctx, const void *src, | |
331 | size_t len) | |
332 | { | |
333 | lib_ring_buffer_write(&client_config, ctx, src, len); | |
334 | } | |
335 | ||
336 | static | |
337 | void lttng_event_write_from_user(struct lib_ring_buffer_ctx *ctx, | |
338 | const void __user *src, size_t len) | |
339 | { | |
340 | lib_ring_buffer_copy_from_user_inatomic(&client_config, ctx, src, len); | |
341 | } | |
342 | ||
343 | static | |
344 | void lttng_event_memset(struct lib_ring_buffer_ctx *ctx, | |
345 | int c, size_t len) | |
346 | { | |
347 | lib_ring_buffer_memset(&client_config, ctx, c, len); | |
348 | } | |
349 | ||
350 | static | |
351 | void lttng_event_strcpy(struct lib_ring_buffer_ctx *ctx, const char *src, | |
352 | size_t len) | |
353 | { | |
354 | lib_ring_buffer_strcpy(&client_config, ctx, src, len, '#'); | |
355 | } | |
356 | ||
357 | static | |
358 | size_t lttng_packet_avail_size(struct channel *chan) | |
359 | { | |
360 | unsigned long o_begin; | |
361 | struct lib_ring_buffer *buf; | |
362 | ||
363 | buf = chan->backend.buf; /* Only for global buffer ! */ | |
364 | o_begin = v_read(&client_config, &buf->offset); | |
365 | if (subbuf_offset(o_begin, chan) != 0) { | |
366 | return chan->backend.subbuf_size - subbuf_offset(o_begin, chan); | |
367 | } else { | |
368 | return chan->backend.subbuf_size - subbuf_offset(o_begin, chan) | |
369 | - sizeof(struct event_notifier_packet_header); | |
370 | } | |
371 | } | |
372 | ||
373 | static | |
374 | wait_queue_head_t *lttng_get_writer_buf_wait_queue(struct channel *chan, int cpu) | |
375 | { | |
376 | struct lib_ring_buffer *buf = channel_get_ring_buffer(&client_config, | |
377 | chan, cpu); | |
378 | return &buf->write_wait; | |
379 | } | |
380 | ||
381 | static | |
382 | wait_queue_head_t *lttng_get_hp_wait_queue(struct channel *chan) | |
383 | { | |
384 | return &chan->hp_wait; | |
385 | } | |
386 | ||
387 | static | |
388 | int lttng_is_finalized(struct channel *chan) | |
389 | { | |
390 | return lib_ring_buffer_channel_is_finalized(chan); | |
391 | } | |
392 | ||
393 | static | |
394 | int lttng_is_disabled(struct channel *chan) | |
395 | { | |
396 | return lib_ring_buffer_channel_is_disabled(chan); | |
397 | } | |
398 | ||
399 | static struct lttng_transport lttng_relay_transport = { | |
400 | .name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING, | |
401 | .owner = THIS_MODULE, | |
402 | .ops = { | |
403 | .channel_create = _channel_create, | |
404 | .channel_destroy = lttng_channel_destroy, | |
405 | .buffer_read_open = lttng_buffer_read_open, | |
406 | .buffer_has_read_closed_stream = | |
407 | lttng_buffer_has_read_closed_stream, | |
408 | .buffer_read_close = lttng_buffer_read_close, | |
409 | .event_reserve = lttng_event_reserve, | |
410 | .event_commit = lttng_event_commit, | |
411 | .event_write_from_user = lttng_event_write_from_user, | |
412 | .event_memset = lttng_event_memset, | |
413 | .event_write = lttng_event_write, | |
414 | .event_strcpy = lttng_event_strcpy, | |
415 | .packet_avail_size = lttng_packet_avail_size, | |
416 | .get_writer_buf_wait_queue = lttng_get_writer_buf_wait_queue, | |
417 | .get_hp_wait_queue = lttng_get_hp_wait_queue, | |
418 | .is_finalized = lttng_is_finalized, | |
419 | .is_disabled = lttng_is_disabled, | |
420 | .timestamp_begin = client_timestamp_begin, | |
421 | .timestamp_end = client_timestamp_end, | |
422 | .events_discarded = client_events_discarded, | |
423 | .content_size = client_content_size, | |
424 | .packet_size = client_packet_size, | |
425 | .stream_id = client_stream_id, | |
426 | .current_timestamp = client_current_timestamp, | |
427 | .sequence_number = client_sequence_number, | |
428 | .instance_id = client_instance_id, | |
429 | }, | |
430 | }; | |
431 | ||
432 | static int __init lttng_ring_buffer_event_notifier_client_init(void) | |
433 | { | |
434 | /* | |
435 | * This vmalloc sync all also takes care of the lib ring buffer | |
436 | * vmalloc'd module pages when it is built as a module into LTTng. | |
437 | */ | |
438 | wrapper_vmalloc_sync_mappings(); | |
439 | lttng_transport_register(<tng_relay_transport); | |
440 | return 0; | |
441 | } | |
442 | ||
443 | module_init(lttng_ring_buffer_event_notifier_client_init); | |
444 | ||
445 | static void __exit lttng_ring_buffer_event_notifier_client_exit(void) | |
446 | { | |
447 | lttng_transport_unregister(<tng_relay_transport); | |
448 | } | |
449 | ||
450 | module_exit(lttng_ring_buffer_event_notifier_client_exit); | |
451 | ||
452 | MODULE_LICENSE("GPL and additional rights"); | |
453 | MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>"); | |
454 | MODULE_DESCRIPTION("LTTng ring buffer " RING_BUFFER_MODE_TEMPLATE_STRING | |
455 | " client"); | |
456 | MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "." | |
457 | __stringify(LTTNG_MODULES_MINOR_VERSION) "." | |
458 | __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION) | |
459 | LTTNG_MODULES_EXTRAVERSION); |