1 /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
3 * lttng-event-notifier-notification.c
5 * Copyright (C) 2020 Francis Deslauriers <francis.deslauriers@efficios.com>
10 #include <lttng/lttng-bytecode.h>
11 #include <lttng/events.h>
12 #include <lttng/msgpack.h>
13 #include <lttng/event-notifier-notification.h>
16 * FIXME: this probably too low but it needs to be below 1024 bytes to avoid
17 * the frame to be larger than the 1024 limit enforced by the kernel.
19 #define CAPTURE_BUFFER_SIZE 512
21 struct lttng_event_notifier_notification
{
23 uint64_t event_notifier_token
;
24 uint8_t capture_buf
[CAPTURE_BUFFER_SIZE
];
25 struct lttng_msgpack_writer writer
;
30 int capture_enum(struct lttng_msgpack_writer
*writer
,
31 struct lttng_interpreter_output
*output
)
36 * Enums are captured as a map containing 2 key-value pairs. Such as:
40 ret
= lttng_msgpack_begin_map(writer
, 2);
46 ret
= lttng_msgpack_write_str(writer
, "type");
52 ret
= lttng_msgpack_write_str(writer
, "enum");
58 ret
= lttng_msgpack_write_str(writer
, "value");
64 switch (output
->type
) {
65 case LTTNG_INTERPRETER_TYPE_SIGNED_ENUM
:
66 ret
= lttng_msgpack_write_signed_integer(writer
, output
->u
.s
);
72 case LTTNG_INTERPRETER_TYPE_UNSIGNED_ENUM
:
73 ret
= lttng_msgpack_write_signed_integer(writer
, output
->u
.u
);
83 ret
= lttng_msgpack_end_map(writer
);
92 int64_t capture_sequence_element_signed(uint8_t *ptr
,
93 const struct lttng_integer_type
*type
)
96 unsigned int size
= type
->size
;
97 bool byte_order_reversed
= type
->reverse_byte_order
;
106 tmp
= *(int16_t *) ptr
;
107 if (byte_order_reversed
)
116 tmp
= *(int32_t *) ptr
;
117 if (byte_order_reversed
)
126 tmp
= *(int64_t *) ptr
;
127 if (byte_order_reversed
)
141 uint64_t capture_sequence_element_unsigned(uint8_t *ptr
,
142 const struct lttng_integer_type
*type
)
145 unsigned int size
= type
->size
;
146 bool byte_order_reversed
= type
->reverse_byte_order
;
155 tmp
= *(uint16_t *) ptr
;
156 if (byte_order_reversed
)
165 tmp
= *(uint32_t *) ptr
;
166 if (byte_order_reversed
)
175 tmp
= *(uint64_t *) ptr
;
176 if (byte_order_reversed
)
189 int capture_sequence(struct lttng_msgpack_writer
*writer
,
190 struct lttng_interpreter_output
*output
)
192 const struct lttng_integer_type
*integer_type
= NULL
;
193 const struct lttng_type
*nested_type
;
198 ret
= lttng_msgpack_begin_array(writer
, output
->u
.sequence
.nr_elem
);
204 ptr
= (uint8_t *) output
->u
.sequence
.ptr
;
205 nested_type
= output
->u
.sequence
.nested_type
;
206 switch (nested_type
->atype
) {
208 integer_type
= &nested_type
->u
.integer
;
210 case atype_enum_nestable
:
211 /* Treat enumeration as an integer. */
212 integer_type
= &nested_type
->u
.enum_nestable
.container_type
->u
.integer
;
215 /* Capture of array of non-integer are not supported. */
218 signedness
= integer_type
->signedness
;
219 for (i
= 0; i
< output
->u
.sequence
.nr_elem
; i
++) {
221 ret
= lttng_msgpack_write_signed_integer(writer
,
222 capture_sequence_element_signed(ptr
, integer_type
));
228 ret
= lttng_msgpack_write_unsigned_integer(writer
,
229 capture_sequence_element_unsigned(ptr
, integer_type
));
237 * We assume that alignment is smaller or equal to the size.
238 * This currently holds true but if it changes in the future,
239 * we will want to change the pointer arithmetics below to
240 * take into account that the next element might be further
243 WARN_ON(integer_type
->alignment
> integer_type
->size
);
245 /* Size is in number of bits. */
246 ptr
+= (integer_type
->size
/ CHAR_BIT
) ;
249 ret
= lttng_msgpack_end_array(writer
);
257 int notification_append_capture(
258 struct lttng_event_notifier_notification
*notif
,
259 struct lttng_interpreter_output
*output
)
261 struct lttng_msgpack_writer
*writer
= ¬if
->writer
;
264 switch (output
->type
) {
265 case LTTNG_INTERPRETER_TYPE_S64
:
266 ret
= lttng_msgpack_write_signed_integer(writer
, output
->u
.s
);
272 case LTTNG_INTERPRETER_TYPE_U64
:
273 ret
= lttng_msgpack_write_unsigned_integer(writer
, output
->u
.u
);
279 case LTTNG_INTERPRETER_TYPE_STRING
:
280 ret
= lttng_msgpack_write_str(writer
, output
->u
.str
.str
);
286 case LTTNG_INTERPRETER_TYPE_SEQUENCE
:
287 ret
= capture_sequence(writer
, output
);
293 case LTTNG_INTERPRETER_TYPE_SIGNED_ENUM
:
294 case LTTNG_INTERPRETER_TYPE_UNSIGNED_ENUM
:
295 ret
= capture_enum(writer
, output
);
310 int notification_append_empty_capture(
311 struct lttng_event_notifier_notification
*notif
)
313 int ret
= lttng_msgpack_write_nil(¬if
->writer
);
321 int notification_init(struct lttng_event_notifier_notification
*notif
,
322 struct lttng_event_notifier
*event_notifier
)
324 struct lttng_msgpack_writer
*writer
= ¬if
->writer
;
327 notif
->has_captures
= false;
329 if (event_notifier
->num_captures
> 0) {
330 lttng_msgpack_writer_init(writer
, notif
->capture_buf
,
331 CAPTURE_BUFFER_SIZE
);
333 ret
= lttng_msgpack_begin_array(writer
, event_notifier
->num_captures
);
339 notif
->has_captures
= true;
347 void notification_send(struct lttng_event_notifier_notification
*notif
,
348 struct lttng_event_notifier
*event_notifier
)
350 struct lttng_event_notifier_group
*event_notifier_group
= event_notifier
->group
;
351 struct lib_ring_buffer_ctx ctx
;
352 struct lttng_kernel_event_notifier_notification kernel_notif
;
353 size_t capture_buffer_content_len
, reserve_size
;
356 reserve_size
= sizeof(kernel_notif
);
357 kernel_notif
.token
= event_notifier
->user_token
;
359 if (notif
->has_captures
) {
360 capture_buffer_content_len
= notif
->writer
.write_pos
- notif
->writer
.buffer
;
362 capture_buffer_content_len
= 0;
365 WARN_ON_ONCE(capture_buffer_content_len
> CAPTURE_BUFFER_SIZE
);
367 reserve_size
+= capture_buffer_content_len
;
368 kernel_notif
.capture_buf_size
= capture_buffer_content_len
;
370 lib_ring_buffer_ctx_init(&ctx
, event_notifier_group
->chan
, NULL
, reserve_size
,
371 lttng_alignof(kernel_notif
), -1);
372 ret
= event_notifier_group
->ops
->event_reserve(&ctx
, 0);
374 //TODO: error handling with counter maps
375 //silently drop for now.
380 lib_ring_buffer_align_ctx(&ctx
, lttng_alignof(kernel_notif
));
382 /* Write the notif structure. */
383 event_notifier_group
->ops
->event_write(&ctx
, &kernel_notif
,
384 sizeof(kernel_notif
));
387 * Write the capture buffer. No need to realigned as the below is a raw
390 event_notifier_group
->ops
->event_write(&ctx
, ¬if
->capture_buf
,
391 capture_buffer_content_len
);
393 event_notifier_group
->ops
->event_commit(&ctx
);
394 irq_work_queue(&event_notifier_group
->wakeup_pending
);
397 void lttng_event_notifier_notification_send(struct lttng_event_notifier
*event_notifier
,
398 struct lttng_probe_ctx
*lttng_probe_ctx
,
399 const char *stack_data
)
401 struct lttng_event_notifier_notification notif
= { 0 };
404 if (unlikely(!READ_ONCE(event_notifier
->enabled
)))
407 ret
= notification_init(¬if
, event_notifier
);
413 if (unlikely(!list_empty(&event_notifier
->capture_bytecode_runtime_head
))) {
414 struct lttng_bytecode_runtime
*capture_bc_runtime
;
417 * Iterate over all the capture bytecodes. If the interpreter
418 * functions returns successfully, append the value of the
419 * `output` parameter to the capture buffer. If the interpreter
420 * fails, append an empty capture to the buffer.
422 list_for_each_entry(capture_bc_runtime
,
423 &event_notifier
->capture_bytecode_runtime_head
, node
) {
424 struct lttng_interpreter_output output
;
426 if (capture_bc_runtime
->interpreter_funcs
.capture(capture_bc_runtime
,
427 lttng_probe_ctx
, stack_data
, &output
) & LTTNG_INTERPRETER_RECORD_FLAG
)
428 ret
= notification_append_capture(¬if
, &output
);
430 ret
= notification_append_empty_capture(¬if
);
433 printk(KERN_WARNING
"Error appending capture to notification");
438 * Send the notification (including the capture buffer) to the
441 notification_send(¬if
, event_notifier
);