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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> |
e8c0bbd3 | 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 | ||
e20c0fec | 31 | static const struct lttng_kernel_ring_buffer_config client_config; |
250c663f MD |
32 | |
33 | static inline | |
860c213b | 34 | u64 lib_ring_buffer_clock_read(struct lttng_kernel_ring_buffer_channel *chan) |
250c663f MD |
35 | { |
36 | return 0; | |
37 | } | |
38 | ||
39 | static inline | |
e20c0fec | 40 | size_t record_header_size(const struct lttng_kernel_ring_buffer_config *config, |
860c213b | 41 | struct lttng_kernel_ring_buffer_channel *chan, size_t offset, |
250c663f | 42 | size_t *pre_header_padding, |
8a57ec02 | 43 | struct lttng_kernel_ring_buffer_ctx *ctx, |
250c663f MD |
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 | ||
860c213b | 61 | static u64 client_ring_buffer_clock_read(struct lttng_kernel_ring_buffer_channel *chan) |
250c663f MD |
62 | { |
63 | return 0; | |
64 | } | |
65 | ||
66 | static | |
e20c0fec | 67 | size_t client_record_header_size(const struct lttng_kernel_ring_buffer_config *config, |
860c213b | 68 | struct lttng_kernel_ring_buffer_channel *chan, size_t offset, |
250c663f | 69 | size_t *pre_header_padding, |
8a57ec02 | 70 | struct lttng_kernel_ring_buffer_ctx *ctx, |
250c663f MD |
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 | ||
e20c0fec | 89 | static void client_buffer_begin(struct lttng_kernel_ring_buffer *buf, u64 tsc, |
250c663f MD |
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 | */ | |
e20c0fec | 98 | static void client_buffer_end(struct lttng_kernel_ring_buffer *buf, u64 tsc, |
b2cf5e0b MD |
99 | unsigned int subbuf_idx, unsigned long data_size, |
100 | const struct lttng_kernel_ring_buffer_ctx *ctx) | |
250c663f MD |
101 | { |
102 | } | |
103 | ||
e20c0fec | 104 | static int client_buffer_create(struct lttng_kernel_ring_buffer *buf, void *priv, |
250c663f MD |
105 | int cpu, const char *name) |
106 | { | |
107 | return 0; | |
108 | } | |
109 | ||
e20c0fec | 110 | static void client_buffer_finalize(struct lttng_kernel_ring_buffer *buf, void *priv, int cpu) |
250c663f MD |
111 | { |
112 | } | |
113 | ||
e20c0fec MD |
114 | static int client_timestamp_begin(const struct lttng_kernel_ring_buffer_config *config, |
115 | struct lttng_kernel_ring_buffer *buf, uint64_t *timestamp_begin) | |
250c663f MD |
116 | { |
117 | return -ENOSYS; | |
118 | } | |
119 | ||
e20c0fec MD |
120 | static int client_timestamp_end(const struct lttng_kernel_ring_buffer_config *config, |
121 | struct lttng_kernel_ring_buffer *bufb, | |
250c663f MD |
122 | uint64_t *timestamp_end) |
123 | { | |
124 | return -ENOSYS; | |
125 | } | |
126 | ||
e20c0fec MD |
127 | static int client_events_discarded(const struct lttng_kernel_ring_buffer_config *config, |
128 | struct lttng_kernel_ring_buffer *bufb, | |
250c663f MD |
129 | uint64_t *events_discarded) |
130 | { | |
131 | return -ENOSYS; | |
132 | } | |
133 | ||
e20c0fec MD |
134 | static int client_current_timestamp(const struct lttng_kernel_ring_buffer_config *config, |
135 | struct lttng_kernel_ring_buffer *bufb, | |
250c663f MD |
136 | uint64_t *ts) |
137 | { | |
138 | return -ENOSYS; | |
139 | } | |
140 | ||
e20c0fec MD |
141 | static int client_content_size(const struct lttng_kernel_ring_buffer_config *config, |
142 | struct lttng_kernel_ring_buffer *bufb, | |
250c663f MD |
143 | uint64_t *content_size) |
144 | { | |
145 | return -ENOSYS; | |
146 | } | |
147 | ||
e20c0fec MD |
148 | static int client_packet_size(const struct lttng_kernel_ring_buffer_config *config, |
149 | struct lttng_kernel_ring_buffer *bufb, | |
250c663f MD |
150 | uint64_t *packet_size) |
151 | { | |
152 | return -ENOSYS; | |
153 | } | |
154 | ||
e20c0fec MD |
155 | static int client_stream_id(const struct lttng_kernel_ring_buffer_config *config, |
156 | struct lttng_kernel_ring_buffer *bufb, | |
250c663f MD |
157 | uint64_t *stream_id) |
158 | { | |
159 | return -ENOSYS; | |
160 | } | |
161 | ||
e20c0fec MD |
162 | static int client_sequence_number(const struct lttng_kernel_ring_buffer_config *config, |
163 | struct lttng_kernel_ring_buffer *bufb, | |
250c663f MD |
164 | uint64_t *seq) |
165 | { | |
166 | return -ENOSYS; | |
167 | } | |
168 | ||
169 | static | |
e20c0fec MD |
170 | int client_instance_id(const struct lttng_kernel_ring_buffer_config *config, |
171 | struct lttng_kernel_ring_buffer *bufb, | |
250c663f MD |
172 | uint64_t *id) |
173 | { | |
174 | return -ENOSYS; | |
175 | } | |
176 | ||
e20c0fec MD |
177 | static void client_record_get(const struct lttng_kernel_ring_buffer_config *config, |
178 | struct lttng_kernel_ring_buffer_channel *chan, struct lttng_kernel_ring_buffer *buf, | |
250c663f MD |
179 | size_t offset, size_t *header_len, |
180 | size_t *payload_len, u64 *timestamp) | |
181 | { | |
182 | struct event_notifier_record_header header; | |
183 | int ret; | |
184 | ||
185 | ret = lib_ring_buffer_read(&buf->backend, offset, &header, | |
186 | offsetof(struct event_notifier_record_header, header_end)); | |
187 | CHAN_WARN_ON(chan, ret != offsetof(struct event_notifier_record_header, header_end)); | |
188 | *header_len = offsetof(struct event_notifier_record_header, header_end); | |
99d223ad | 189 | *payload_len = header.payload_len; |
250c663f MD |
190 | *timestamp = 0; |
191 | } | |
192 | ||
e20c0fec | 193 | static const struct lttng_kernel_ring_buffer_config client_config = { |
250c663f MD |
194 | .cb.ring_buffer_clock_read = client_ring_buffer_clock_read, |
195 | .cb.record_header_size = client_record_header_size, | |
196 | .cb.subbuffer_header_size = client_packet_header_size, | |
197 | .cb.buffer_begin = client_buffer_begin, | |
198 | .cb.buffer_end = client_buffer_end, | |
199 | .cb.buffer_create = client_buffer_create, | |
200 | .cb.buffer_finalize = client_buffer_finalize, | |
201 | .cb.record_get = client_record_get, | |
202 | ||
203 | .tsc_bits = 0, | |
204 | .alloc = RING_BUFFER_ALLOC_GLOBAL, | |
205 | .sync = RING_BUFFER_SYNC_GLOBAL, | |
206 | .mode = RING_BUFFER_MODE_TEMPLATE, | |
207 | .backend = RING_BUFFER_PAGE, | |
208 | .output = RING_BUFFER_OUTPUT_TEMPLATE, | |
209 | .oops = RING_BUFFER_OOPS_CONSISTENCY, | |
210 | .ipi = RING_BUFFER_NO_IPI_BARRIER, | |
211 | .wakeup = RING_BUFFER_WAKEUP_BY_WRITER, | |
212 | }; | |
213 | ||
214 | static | |
215 | void release_priv_ops(void *priv_ops) | |
216 | { | |
217 | module_put(THIS_MODULE); | |
218 | } | |
219 | ||
220 | static | |
860c213b | 221 | void lttng_channel_destroy(struct lttng_kernel_ring_buffer_channel *chan) |
250c663f MD |
222 | { |
223 | channel_destroy(chan); | |
224 | } | |
225 | ||
226 | static | |
860c213b | 227 | struct lttng_kernel_ring_buffer_channel *_channel_create(const char *name, |
250c663f MD |
228 | void *priv, void *buf_addr, |
229 | size_t subbuf_size, size_t num_subbuf, | |
230 | unsigned int switch_timer_interval, | |
231 | unsigned int read_timer_interval) | |
232 | { | |
233 | struct lttng_event_notifier_group *event_notifier_group = priv; | |
860c213b | 234 | struct lttng_kernel_ring_buffer_channel *chan; |
250c663f MD |
235 | |
236 | chan = channel_create(&client_config, name, | |
237 | event_notifier_group, buf_addr, | |
238 | subbuf_size, num_subbuf, switch_timer_interval, | |
239 | read_timer_interval); | |
240 | if (chan) { | |
241 | /* | |
242 | * Ensure this module is not unloaded before we finish | |
243 | * using lttng_relay_transport.ops. | |
244 | */ | |
245 | if (!try_module_get(THIS_MODULE)) { | |
246 | printk(KERN_WARNING "LTTng: Can't lock event_notifier transport module.\n"); | |
247 | goto error; | |
248 | } | |
249 | chan->backend.priv_ops = <tng_relay_transport.ops; | |
250 | chan->backend.release_priv_ops = release_priv_ops; | |
251 | } | |
252 | return chan; | |
253 | ||
254 | error: | |
255 | lttng_channel_destroy(chan); | |
256 | return NULL; | |
257 | } | |
258 | ||
259 | static | |
e20c0fec | 260 | struct lttng_kernel_ring_buffer *lttng_buffer_read_open(struct lttng_kernel_ring_buffer_channel *chan) |
250c663f | 261 | { |
e20c0fec | 262 | struct lttng_kernel_ring_buffer *buf; |
250c663f MD |
263 | |
264 | buf = channel_get_ring_buffer(&client_config, chan, 0); | |
265 | if (!lib_ring_buffer_open_read(buf)) | |
266 | return buf; | |
267 | return NULL; | |
268 | } | |
269 | ||
270 | static | |
860c213b | 271 | int lttng_buffer_has_read_closed_stream(struct lttng_kernel_ring_buffer_channel *chan) |
250c663f | 272 | { |
e20c0fec | 273 | struct lttng_kernel_ring_buffer *buf; |
250c663f MD |
274 | int cpu; |
275 | ||
276 | for_each_channel_cpu(cpu, chan) { | |
277 | buf = channel_get_ring_buffer(&client_config, chan, cpu); | |
278 | if (!atomic_long_read(&buf->active_readers)) | |
279 | return 1; | |
280 | } | |
281 | return 0; | |
282 | } | |
283 | ||
284 | static | |
e20c0fec | 285 | void lttng_buffer_read_close(struct lttng_kernel_ring_buffer *buf) |
250c663f MD |
286 | { |
287 | lib_ring_buffer_release_read(buf); | |
288 | } | |
289 | ||
99d223ad | 290 | static |
e20c0fec | 291 | void lttng_write_event_notifier_header(const struct lttng_kernel_ring_buffer_config *config, |
8a57ec02 | 292 | struct lttng_kernel_ring_buffer_ctx *ctx) |
99d223ad FD |
293 | { |
294 | uint32_t data_size; | |
295 | ||
296 | WARN_ON_ONCE(ctx->data_size > U32_MAX); | |
297 | ||
298 | data_size = (uint32_t) ctx->data_size; | |
299 | ||
300 | lib_ring_buffer_write(config, ctx, &data_size, sizeof(data_size)); | |
301 | ||
302 | lib_ring_buffer_align_ctx(ctx, ctx->largest_align); | |
303 | } | |
304 | ||
250c663f | 305 | static |
8a57ec02 | 306 | int lttng_event_reserve(struct lttng_kernel_ring_buffer_ctx *ctx) |
250c663f | 307 | { |
860c213b | 308 | struct lttng_kernel_ring_buffer_channel *chan = ctx->client_priv; |
250c663f MD |
309 | int ret; |
310 | ||
b1199bd3 MD |
311 | memset(&ctx->priv, 0, sizeof(ctx->priv)); |
312 | ctx->priv.chan = chan; | |
313 | ||
250c663f MD |
314 | ret = lib_ring_buffer_reserve(&client_config, ctx, NULL); |
315 | if (ret) | |
316 | return ret; | |
317 | lib_ring_buffer_backend_get_pages(&client_config, ctx, | |
b1199bd3 | 318 | &ctx->priv.backend_pages); |
99d223ad FD |
319 | |
320 | lttng_write_event_notifier_header(&client_config, ctx); | |
250c663f MD |
321 | return 0; |
322 | } | |
323 | ||
324 | static | |
8a57ec02 | 325 | void lttng_event_commit(struct lttng_kernel_ring_buffer_ctx *ctx) |
250c663f MD |
326 | { |
327 | lib_ring_buffer_commit(&client_config, ctx); | |
328 | } | |
329 | ||
330 | static | |
8a57ec02 | 331 | void lttng_event_write(struct lttng_kernel_ring_buffer_ctx *ctx, const void *src, |
f5ffbd77 | 332 | size_t len, size_t alignment) |
250c663f | 333 | { |
f5ffbd77 | 334 | lib_ring_buffer_align_ctx(ctx, alignment); |
250c663f MD |
335 | lib_ring_buffer_write(&client_config, ctx, src, len); |
336 | } | |
337 | ||
338 | static | |
8a57ec02 | 339 | void lttng_event_write_from_user(struct lttng_kernel_ring_buffer_ctx *ctx, |
f5ffbd77 | 340 | const void __user *src, size_t len, size_t alignment) |
250c663f | 341 | { |
f5ffbd77 | 342 | lib_ring_buffer_align_ctx(ctx, alignment); |
250c663f MD |
343 | lib_ring_buffer_copy_from_user_inatomic(&client_config, ctx, src, len); |
344 | } | |
345 | ||
346 | static | |
8a57ec02 | 347 | void lttng_event_memset(struct lttng_kernel_ring_buffer_ctx *ctx, |
250c663f MD |
348 | int c, size_t len) |
349 | { | |
350 | lib_ring_buffer_memset(&client_config, ctx, c, len); | |
351 | } | |
352 | ||
353 | static | |
8a57ec02 | 354 | void lttng_event_strcpy(struct lttng_kernel_ring_buffer_ctx *ctx, const char *src, |
250c663f MD |
355 | size_t len) |
356 | { | |
357 | lib_ring_buffer_strcpy(&client_config, ctx, src, len, '#'); | |
358 | } | |
359 | ||
360 | static | |
860c213b | 361 | size_t lttng_packet_avail_size(struct lttng_kernel_ring_buffer_channel *chan) |
250c663f MD |
362 | { |
363 | unsigned long o_begin; | |
e20c0fec | 364 | struct lttng_kernel_ring_buffer *buf; |
250c663f MD |
365 | |
366 | buf = chan->backend.buf; /* Only for global buffer ! */ | |
367 | o_begin = v_read(&client_config, &buf->offset); | |
368 | if (subbuf_offset(o_begin, chan) != 0) { | |
369 | return chan->backend.subbuf_size - subbuf_offset(o_begin, chan); | |
370 | } else { | |
371 | return chan->backend.subbuf_size - subbuf_offset(o_begin, chan) | |
372 | - sizeof(struct event_notifier_packet_header); | |
373 | } | |
374 | } | |
375 | ||
376 | static | |
860c213b | 377 | wait_queue_head_t *lttng_get_writer_buf_wait_queue(struct lttng_kernel_ring_buffer_channel *chan, int cpu) |
250c663f | 378 | { |
e20c0fec | 379 | struct lttng_kernel_ring_buffer *buf = channel_get_ring_buffer(&client_config, |
250c663f MD |
380 | chan, cpu); |
381 | return &buf->write_wait; | |
382 | } | |
383 | ||
384 | static | |
860c213b | 385 | wait_queue_head_t *lttng_get_hp_wait_queue(struct lttng_kernel_ring_buffer_channel *chan) |
250c663f MD |
386 | { |
387 | return &chan->hp_wait; | |
388 | } | |
389 | ||
390 | static | |
860c213b | 391 | int lttng_is_finalized(struct lttng_kernel_ring_buffer_channel *chan) |
250c663f MD |
392 | { |
393 | return lib_ring_buffer_channel_is_finalized(chan); | |
394 | } | |
395 | ||
396 | static | |
860c213b | 397 | int lttng_is_disabled(struct lttng_kernel_ring_buffer_channel *chan) |
250c663f MD |
398 | { |
399 | return lib_ring_buffer_channel_is_disabled(chan); | |
400 | } | |
401 | ||
402 | static struct lttng_transport lttng_relay_transport = { | |
403 | .name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING, | |
404 | .owner = THIS_MODULE, | |
405 | .ops = { | |
4a399b76 MD |
406 | .priv = __LTTNG_COMPOUND_LITERAL(struct lttng_kernel_channel_buffer_ops_private, { |
407 | .pub = <tng_relay_transport.ops, | |
408 | .channel_create = _channel_create, | |
409 | .channel_destroy = lttng_channel_destroy, | |
410 | .buffer_read_open = lttng_buffer_read_open, | |
411 | .buffer_has_read_closed_stream = | |
412 | lttng_buffer_has_read_closed_stream, | |
413 | .buffer_read_close = lttng_buffer_read_close, | |
414 | .packet_avail_size = lttng_packet_avail_size, | |
415 | .get_writer_buf_wait_queue = lttng_get_writer_buf_wait_queue, | |
416 | .get_hp_wait_queue = lttng_get_hp_wait_queue, | |
417 | .is_finalized = lttng_is_finalized, | |
418 | .is_disabled = lttng_is_disabled, | |
419 | .timestamp_begin = client_timestamp_begin, | |
420 | .timestamp_end = client_timestamp_end, | |
421 | .events_discarded = client_events_discarded, | |
422 | .content_size = client_content_size, | |
423 | .packet_size = client_packet_size, | |
424 | .stream_id = client_stream_id, | |
425 | .current_timestamp = client_current_timestamp, | |
426 | .sequence_number = client_sequence_number, | |
427 | .instance_id = client_instance_id, | |
428 | }), | |
250c663f MD |
429 | .event_reserve = lttng_event_reserve, |
430 | .event_commit = lttng_event_commit, | |
431 | .event_write_from_user = lttng_event_write_from_user, | |
432 | .event_memset = lttng_event_memset, | |
433 | .event_write = lttng_event_write, | |
434 | .event_strcpy = lttng_event_strcpy, | |
250c663f MD |
435 | }, |
436 | }; | |
437 | ||
438 | static int __init lttng_ring_buffer_event_notifier_client_init(void) | |
439 | { | |
440 | /* | |
441 | * This vmalloc sync all also takes care of the lib ring buffer | |
442 | * vmalloc'd module pages when it is built as a module into LTTng. | |
443 | */ | |
444 | wrapper_vmalloc_sync_mappings(); | |
445 | lttng_transport_register(<tng_relay_transport); | |
446 | return 0; | |
447 | } | |
448 | ||
449 | module_init(lttng_ring_buffer_event_notifier_client_init); | |
450 | ||
451 | static void __exit lttng_ring_buffer_event_notifier_client_exit(void) | |
452 | { | |
453 | lttng_transport_unregister(<tng_relay_transport); | |
454 | } | |
455 | ||
456 | module_exit(lttng_ring_buffer_event_notifier_client_exit); | |
457 | ||
458 | MODULE_LICENSE("GPL and additional rights"); | |
459 | MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>"); | |
460 | MODULE_DESCRIPTION("LTTng ring buffer " RING_BUFFER_MODE_TEMPLATE_STRING | |
461 | " client"); | |
462 | MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "." | |
463 | __stringify(LTTNG_MODULES_MINOR_VERSION) "." | |
464 | __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION) | |
465 | LTTNG_MODULES_EXTRAVERSION); |