[lttng-ust.git] / liblttng-ust / event-notifier-notification.c

/*
 * SPDX-License-Identifier: LGPL-2.1-only
 *
 * Copyright (C) 2020 Francis Deslauriers <francis.deslauriers@efficios.com>
 */

#define _LGPL_SOURCE

#include <assert.h>
#include <errno.h>
#include <limits.h>

#include <lttng/ust-endian.h>
#include <usterr-signal-safe.h>
#include <urcu/rculist.h>

#include "ust-events-internal.h"
#include "../libmsgpack/msgpack.h"
#include "lttng-bytecode.h"
#include "ust-share.h"

/*
 * We want this write to be atomic AND non-blocking, meaning that we
 * want to write either everything OR nothing.
 * According to `pipe(7)`, writes that are less than `PIPE_BUF` bytes must be
 * atomic, so we bound the capture buffer size to the `PIPE_BUF` minus the size
 * of the notification struct we are sending alongside the capture buffer.
 */
#define CAPTURE_BUFFER_SIZE \
	(PIPE_BUF - sizeof(struct lttng_ust_abi_event_notifier_notification) - 1)

struct lttng_event_notifier_notification {
	int notification_fd;
	uint64_t event_notifier_token;
	uint8_t capture_buf[CAPTURE_BUFFER_SIZE];
	struct lttng_msgpack_writer writer;
	bool has_captures;
};

static
void capture_enum(struct lttng_msgpack_writer *writer,
		struct lttng_interpreter_output *output)
{
	lttng_msgpack_begin_map(writer, 2);
	lttng_msgpack_write_str(writer, "type");
	lttng_msgpack_write_str(writer, "enum");

	lttng_msgpack_write_str(writer, "value");

	switch (output->type) {
	case LTTNG_INTERPRETER_TYPE_SIGNED_ENUM:
		lttng_msgpack_write_signed_integer(writer, output->u.s);
		break;
	case LTTNG_INTERPRETER_TYPE_UNSIGNED_ENUM:
		lttng_msgpack_write_signed_integer(writer, output->u.u);
		break;
	default:
		abort();
	}

	lttng_msgpack_end_map(writer);
}

static
int64_t capture_sequence_element_signed(uint8_t *ptr,
		struct lttng_ust_type_integer *integer_type)
{
	int64_t value;
	unsigned int size = integer_type->size;
	bool byte_order_reversed = integer_type->reverse_byte_order;

	switch (size) {
	case 8:
		value = *ptr;
		break;
	case 16:
	{
		int16_t tmp;
		tmp = *(int16_t *) ptr;
		if (byte_order_reversed)
			tmp = bswap_16(tmp);

		value = tmp;
		break;
	}
	case 32:
	{
		int32_t tmp;
		tmp = *(int32_t *) ptr;
		if (byte_order_reversed)
			tmp = bswap_32(tmp);

		value = tmp;
		break;
	}
	case 64:
	{
		int64_t tmp;
		tmp = *(int64_t *) ptr;
		if (byte_order_reversed)
			tmp = bswap_64(tmp);

		value = tmp;
		break;
	}
	default:
		abort();
	}

	return value;
}

static
uint64_t capture_sequence_element_unsigned(uint8_t *ptr,
		struct lttng_ust_type_integer *integer_type)
{
	uint64_t value;
	unsigned int size = integer_type->size;
	bool byte_order_reversed = integer_type->reverse_byte_order;

	switch (size) {
	case 8:
		value = *ptr;
		break;
	case 16:
	{
		uint16_t tmp;
		tmp = *(uint16_t *) ptr;
		if (byte_order_reversed)
			tmp = bswap_16(tmp);

		value = tmp;
		break;
	}
	case 32:
	{
		uint32_t tmp;
		tmp = *(uint32_t *) ptr;
		if (byte_order_reversed)
			tmp = bswap_32(tmp);

		value = tmp;
		break;
	}
	case 64:
	{
		uint64_t tmp;
		tmp = *(uint64_t *) ptr;
		if (byte_order_reversed)
			tmp = bswap_64(tmp);

		value = tmp;
		break;
	}
	default:
		abort();
	}

	return value;
}

static
void capture_sequence(struct lttng_msgpack_writer *writer,
		struct lttng_interpreter_output *output)
{
	struct lttng_ust_type_integer *integer_type;
	struct lttng_ust_type_common *nested_type;
	uint8_t *ptr;
	bool signedness;
	int i;

	lttng_msgpack_begin_array(writer, output->u.sequence.nr_elem);

	ptr = (uint8_t *) output->u.sequence.ptr;
	nested_type = output->u.sequence.nested_type;
	switch (nested_type->type) {
	case lttng_ust_type_integer:
		integer_type = lttng_ust_get_type_integer(nested_type);
		break;
	case lttng_ust_type_enum:
		/* Treat enumeration as an integer. */
		integer_type = lttng_ust_get_type_integer(lttng_ust_get_type_enum(nested_type)->container_type);
		break;
	default:
		/* Capture of array of non-integer are not supported. */
		abort();
	}
	signedness = integer_type->signedness;
	for (i = 0; i < output->u.sequence.nr_elem; i++) {
		if (signedness) {
			lttng_msgpack_write_signed_integer(writer,
				capture_sequence_element_signed(ptr, integer_type));
		} else {
			lttng_msgpack_write_unsigned_integer(writer,
				capture_sequence_element_unsigned(ptr, integer_type));
		}

		/*
		 * We assume that alignment is smaller or equal to the size.
		 * This currently holds true but if it changes in the future,
		 * we will want to change the pointer arithmetics below to
		 * take into account that the next element might be further
		 * away.
		 */
		assert(integer_type->alignment <= integer_type->size);

		/* Size is in number of bits. */
		ptr += (integer_type->size / CHAR_BIT) ;
	}

	lttng_msgpack_end_array(writer);
}

static
void notification_init(struct lttng_event_notifier_notification *notif,
		struct lttng_ust_event_notifier *event_notifier)
{
	struct lttng_msgpack_writer *writer = &notif->writer;

	notif->event_notifier_token = event_notifier->priv->parent.user_token;
	notif->notification_fd = event_notifier->priv->group->notification_fd;
	notif->has_captures = false;

	if (event_notifier->priv->num_captures > 0) {
		lttng_msgpack_writer_init(writer, notif->capture_buf,
				CAPTURE_BUFFER_SIZE);

		lttng_msgpack_begin_array(writer, event_notifier->priv->num_captures);
		notif->has_captures = true;
	}
}

static
void notification_append_capture(
		struct lttng_event_notifier_notification *notif,
		struct lttng_interpreter_output *output)
{
	struct lttng_msgpack_writer *writer = &notif->writer;

	switch (output->type) {
	case LTTNG_INTERPRETER_TYPE_S64:
		lttng_msgpack_write_signed_integer(writer, output->u.s);
		break;
	case LTTNG_INTERPRETER_TYPE_U64:
		lttng_msgpack_write_unsigned_integer(writer, output->u.u);
		break;
	case LTTNG_INTERPRETER_TYPE_DOUBLE:
		lttng_msgpack_write_double(writer, output->u.d);
		break;
	case LTTNG_INTERPRETER_TYPE_STRING:
		lttng_msgpack_write_str(writer, output->u.str.str);
		break;
	case LTTNG_INTERPRETER_TYPE_SEQUENCE:
		capture_sequence(writer, output);
		break;
	case LTTNG_INTERPRETER_TYPE_SIGNED_ENUM:
	case LTTNG_INTERPRETER_TYPE_UNSIGNED_ENUM:
		capture_enum(writer, output);
		break;
	default:
		abort();
	}
}

static
void notification_append_empty_capture(
		struct lttng_event_notifier_notification *notif)
{
	lttng_msgpack_write_nil(&notif->writer);
}

static void record_error(struct lttng_ust_event_notifier *event_notifier)
{
	struct lttng_event_notifier_group *event_notifier_group =
			event_notifier->priv->group;
	struct lttng_counter *error_counter;
	size_t dimension_index[1];
	int ret;

	error_counter = CMM_LOAD_SHARED(event_notifier_group->error_counter);
	/*
	 * load-acquire paired with store-release orders creation of the
	 * error counter and setting error_counter_len before the
	 * error_counter is used.
	 * Currently a full memory barrier is used, which could be
	 * turned into acquire-release barriers.
	 */
	cmm_smp_mb();
	/* This group may not have an error counter attached to it. */
	if (!error_counter)
		return;

	dimension_index[0] = event_notifier->priv->error_counter_index;
	ret = event_notifier_group->error_counter->ops->counter_add(
			error_counter->counter, dimension_index, 1);
	if (ret)
		WARN_ON_ONCE(1);
}

static
void notification_send(struct lttng_event_notifier_notification *notif,
		struct lttng_ust_event_notifier *event_notifier)
{
	ssize_t ret;
	size_t content_len;
	int iovec_count = 1;
	struct lttng_ust_abi_event_notifier_notification ust_notif = {0};
	struct iovec iov[2];

	assert(notif);

	ust_notif.token = event_notifier->priv->parent.user_token;

	/*
	 * Prepare sending the notification from multiple buffers using an
	 * array of `struct iovec`. The first buffer of the vector is
	 * notification structure itself and is always present.
	 */
	iov[0].iov_base = &ust_notif;
	iov[0].iov_len = sizeof(ust_notif);

	if (notif->has_captures) {
		/*
		 * If captures were requested, the second buffer of the array
		 * is the capture buffer.
		 */
		assert(notif->writer.buffer);
		content_len = notif->writer.write_pos - notif->writer.buffer;

		assert(content_len > 0 && content_len <= CAPTURE_BUFFER_SIZE);

		iov[1].iov_base = notif->capture_buf;
		iov[1].iov_len = content_len;

		iovec_count++;
	} else {
		content_len = 0;
	}

	/*
	 * Update the capture buffer size so that receiver of the buffer will
	 * know how much to expect.
	 */
	ust_notif.capture_buf_size = content_len;

	/* Send all the buffers. */
	ret = ust_patient_writev(notif->notification_fd, iov, iovec_count);
	if (ret == -1) {
		if (errno == EAGAIN) {
			record_error(event_notifier);
			DBG("Cannot send event_notifier notification without blocking: %s",
				strerror(errno));
		} else {
			DBG("Error to sending event notifier notification: %s",
				strerror(errno));
			abort();
		}
	}
}

void lttng_event_notifier_notification_send(
		struct lttng_ust_event_notifier *event_notifier,
		const char *stack_data,
		struct lttng_ust_notification_ctx *notif_ctx)
{
	/*
	 * This function is called from the probe, we must do dynamic
	 * allocation in this context.
	 */
	struct lttng_event_notifier_notification notif = {0};

	notification_init(&notif, event_notifier);

	if (caa_unlikely(notif_ctx->eval_capture)) {
		struct lttng_ust_bytecode_runtime *capture_bc_runtime;

		/*
		 * Iterate over all the capture bytecodes. If the interpreter
		 * functions returns successfully, append the value of the
		 * `output` parameter to the capture buffer. If the interpreter
		 * fails, append an empty capture to the buffer.
		 */
		cds_list_for_each_entry_rcu(capture_bc_runtime,
				&event_notifier->priv->capture_bytecode_runtime_head, node) {
			struct lttng_interpreter_output output;

			if (capture_bc_runtime->interpreter_func(capture_bc_runtime,
					stack_data, &output) == LTTNG_UST_BYTECODE_INTERPRETER_OK)
				notification_append_capture(&notif, &output);
			else
				notification_append_empty_capture(&notif);
		}
	}

	/*
	 * Send the notification (including the capture buffer) to the
	 * sessiond.
	 */
	notification_send(&notif, event_notifier);
}
Commit	Line	Data
d8d2416d	1	/*
c0c0989a	2	* SPDX-License-Identifier: LGPL-2.1-only
d8d2416d FD	3	*
d8d2416d FD	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>
9af5d97a MJ	12
f03092d7	13	#include <lttng/ust-endian.h>
d8d2416d	14	#include <usterr-signal-safe.h>
a2e4d05e	15	#include <urcu/rculist.h>
d8d2416d	16
bb7ad29d	17	#include "ust-events-internal.h"
b9f82a28 FD	18	#include "../libmsgpack/msgpack.h"
b9f82a28 FD	19	#include "lttng-bytecode.h"
864a1eda	20	#include "ust-share.h"
d8d2416d	21
d37ecb3f FD	22	/*
	23	* We want this write to be atomic AND non-blocking, meaning that we
	24	* want to write either everything OR nothing.
	25	* According to `pipe(7)`, writes that are less than `PIPE_BUF` bytes must be
	26	* atomic, so we bound the capture buffer size to the `PIPE_BUF` minus the size
	27	* of the notification struct we are sending alongside the capture buffer.
	28	*/
	29	#define CAPTURE_BUFFER_SIZE \
fd17d7ce	30	(PIPE_BUF - sizeof(struct lttng_ust_abi_event_notifier_notification) - 1)
d37ecb3f FD	31
	32	struct lttng_event_notifier_notification {
	33	int notification_fd;
	34	uint64_t event_notifier_token;
	35	uint8_t capture_buf[CAPTURE_BUFFER_SIZE];
	36	struct lttng_msgpack_writer writer;
	37	bool has_captures;
	38	};
	39
b9f82a28 FD	40	static
	41	void capture_enum(struct lttng_msgpack_writer *writer,
	42	struct lttng_interpreter_output *output)
	43	{
	44	lttng_msgpack_begin_map(writer, 2);
	45	lttng_msgpack_write_str(writer, "type");
	46	lttng_msgpack_write_str(writer, "enum");
	47
	48	lttng_msgpack_write_str(writer, "value");
	49
	50	switch (output->type) {
	51	case LTTNG_INTERPRETER_TYPE_SIGNED_ENUM:
	52	lttng_msgpack_write_signed_integer(writer, output->u.s);
	53	break;
	54	case LTTNG_INTERPRETER_TYPE_UNSIGNED_ENUM:
	55	lttng_msgpack_write_signed_integer(writer, output->u.u);
	56	break;
	57	default:
	58	abort();
	59	}
	60
	61	lttng_msgpack_end_map(writer);
	62	}
	63
	64	static
	65	int64_t capture_sequence_element_signed(uint8_t *ptr,
a084756d	66	struct lttng_ust_type_integer *integer_type)
b9f82a28 FD	67	{
b9f82a28 FD	68	int64_t value;
a084756d MD	69	unsigned int size = integer_type->size;
a084756d MD	70	bool byte_order_reversed = integer_type->reverse_byte_order;
b9f82a28 FD	71
	72	switch (size) {
	73	case 8:
	74	value = *ptr;
	75	break;
	76	case 16:
	77	{
	78	int16_t tmp;
	79	tmp = (int16_t ) ptr;
	80	if (byte_order_reversed)
	81	tmp = bswap_16(tmp);
	82
	83	value = tmp;
	84	break;
	85	}
	86	case 32:
	87	{
	88	int32_t tmp;
	89	tmp = (int32_t ) ptr;
	90	if (byte_order_reversed)
	91	tmp = bswap_32(tmp);
	92
	93	value = tmp;
	94	break;
	95	}
	96	case 64:
	97	{
	98	int64_t tmp;
	99	tmp = (int64_t ) ptr;
	100	if (byte_order_reversed)
	101	tmp = bswap_64(tmp);
	102
	103	value = tmp;
	104	break;
	105	}
	106	default:
	107	abort();
	108	}
	109
	110	return value;
	111	}
	112
	113	static
	114	uint64_t capture_sequence_element_unsigned(uint8_t *ptr,
a084756d	115	struct lttng_ust_type_integer *integer_type)
b9f82a28 FD	116	{
b9f82a28 FD	117	uint64_t value;
a084756d MD	118	unsigned int size = integer_type->size;
a084756d MD	119	bool byte_order_reversed = integer_type->reverse_byte_order;
b9f82a28 FD	120
	121	switch (size) {
	122	case 8:
	123	value = *ptr;
	124	break;
	125	case 16:
	126	{
	127	uint16_t tmp;
	128	tmp = (uint16_t ) ptr;
	129	if (byte_order_reversed)
	130	tmp = bswap_16(tmp);
	131
	132	value = tmp;
	133	break;
	134	}
	135	case 32:
	136	{
	137	uint32_t tmp;
	138	tmp = (uint32_t ) ptr;
	139	if (byte_order_reversed)
	140	tmp = bswap_32(tmp);
	141
	142	value = tmp;
	143	break;
	144	}
	145	case 64:
	146	{
	147	uint64_t tmp;
	148	tmp = (uint64_t ) ptr;
	149	if (byte_order_reversed)
	150	tmp = bswap_64(tmp);
	151
	152	value = tmp;
	153	break;
	154	}
	155	default:
	156	abort();
	157	}
	158
	159	return value;
	160	}
	161
b9f82a28 FD	162	static
	163	void capture_sequence(struct lttng_msgpack_writer *writer,
	164	struct lttng_interpreter_output *output)
	165	{
a084756d MD	166	struct lttng_ust_type_integer *integer_type;
a084756d MD	167	struct lttng_ust_type_common *nested_type;
b9f82a28 FD	168	uint8_t *ptr;
	169	bool signedness;
	170	int i;
	171
	172	lttng_msgpack_begin_array(writer, output->u.sequence.nr_elem);
	173
	174	ptr = (uint8_t *) output->u.sequence.ptr;
	175	nested_type = output->u.sequence.nested_type;
a084756d MD	176	switch (nested_type->type) {
	177	case lttng_ust_type_integer:
	178	integer_type = lttng_ust_get_type_integer(nested_type);
b9f82a28	179	break;
a084756d	180	case lttng_ust_type_enum:
b9f82a28	181	/* Treat enumeration as an integer. */
a084756d	182	integer_type = lttng_ust_get_type_integer(lttng_ust_get_type_enum(nested_type)->container_type);
b9f82a28 FD	183	break;
	184	default:
	185	/* Capture of array of non-integer are not supported. */
	186	abort();
	187	}
	188	signedness = integer_type->signedness;
	189	for (i = 0; i < output->u.sequence.nr_elem; i++) {
	190	if (signedness) {
	191	lttng_msgpack_write_signed_integer(writer,
	192	capture_sequence_element_signed(ptr, integer_type));
	193	} else {
	194	lttng_msgpack_write_unsigned_integer(writer,
	195	capture_sequence_element_unsigned(ptr, integer_type));
	196	}
	197
	198	/*
	199	* We assume that alignment is smaller or equal to the size.
	200	* This currently holds true but if it changes in the future,
	201	* we will want to change the pointer arithmetics below to
	202	* take into account that the next element might be further
	203	* away.
	204	*/
	205	assert(integer_type->alignment <= integer_type->size);
	206
	207	/* Size is in number of bits. */
	208	ptr += (integer_type->size / CHAR_BIT) ;
	209	}
	210
	211	lttng_msgpack_end_array(writer);
	212	}
	213
d37ecb3f FD	214	static
d37ecb3f FD	215	void notification_init(struct lttng_event_notifier_notification *notif,
d7d45c0d	216	struct lttng_ust_event_notifier *event_notifier)
d8d2416d	217	{
d37ecb3f FD	218	struct lttng_msgpack_writer *writer = &notif->writer;
d37ecb3f FD	219
115db533 MD	220	notif->event_notifier_token = event_notifier->priv->parent.user_token;
115db533 MD	221	notif->notification_fd = event_notifier->priv->group->notification_fd;
d37ecb3f FD	222	notif->has_captures = false;
d37ecb3f FD	223
115db533	224	if (event_notifier->priv->num_captures > 0) {
d37ecb3f FD	225	lttng_msgpack_writer_init(writer, notif->capture_buf,
	226	CAPTURE_BUFFER_SIZE);
	227
115db533	228	lttng_msgpack_begin_array(writer, event_notifier->priv->num_captures);
d37ecb3f FD	229	notif->has_captures = true;
	230	}
	231	}
	232
	233	static
	234	void notification_append_capture(
	235	struct lttng_event_notifier_notification *notif,
	236	struct lttng_interpreter_output *output)
	237	{
	238	struct lttng_msgpack_writer *writer = &notif->writer;
	239
	240	switch (output->type) {
	241	case LTTNG_INTERPRETER_TYPE_S64:
	242	lttng_msgpack_write_signed_integer(writer, output->u.s);
	243	break;
	244	case LTTNG_INTERPRETER_TYPE_U64:
	245	lttng_msgpack_write_unsigned_integer(writer, output->u.u);
	246	break;
	247	case LTTNG_INTERPRETER_TYPE_DOUBLE:
	248	lttng_msgpack_write_double(writer, output->u.d);
	249	break;
	250	case LTTNG_INTERPRETER_TYPE_STRING:
	251	lttng_msgpack_write_str(writer, output->u.str.str);
	252	break;
	253	case LTTNG_INTERPRETER_TYPE_SEQUENCE:
	254	capture_sequence(writer, output);
	255	break;
	256	case LTTNG_INTERPRETER_TYPE_SIGNED_ENUM:
	257	case LTTNG_INTERPRETER_TYPE_UNSIGNED_ENUM:
	258	capture_enum(writer, output);
	259	break;
	260	default:
	261	abort();
	262	}
	263	}
	264
	265	static
	266	void notification_append_empty_capture(
	267	struct lttng_event_notifier_notification *notif)
	268	{
	269	lttng_msgpack_write_nil(&notif->writer);
	270	}
	271
d7d45c0d	272	static void record_error(struct lttng_ust_event_notifier *event_notifier)
6566528b FD	273	{
6566528b FD	274	struct lttng_event_notifier_group *event_notifier_group =
115db533	275	event_notifier->priv->group;
33f43caa	276	struct lttng_counter *error_counter;
6566528b FD	277	size_t dimension_index[1];
	278	int ret;
	279
33f43caa MD	280	error_counter = CMM_LOAD_SHARED(event_notifier_group->error_counter);
	281	/*
	282	* load-acquire paired with store-release orders creation of the
	283	* error counter and setting error_counter_len before the
	284	* error_counter is used.
	285	* Currently a full memory barrier is used, which could be
	286	* turned into acquire-release barriers.
	287	*/
	288	cmm_smp_mb();
c30ad764	289	/* This group may not have an error counter attached to it. */
33f43caa	290	if (!error_counter)
c30ad764 MD	291	return;
c30ad764 MD	292
115db533	293	dimension_index[0] = event_notifier->priv->error_counter_index;
6566528b	294	ret = event_notifier_group->error_counter->ops->counter_add(
33f43caa	295	error_counter->counter, dimension_index, 1);
6566528b FD	296	if (ret)
	297	WARN_ON_ONCE(1);
	298	}
	299
d37ecb3f	300	static
6566528b	301	void notification_send(struct lttng_event_notifier_notification *notif,
d7d45c0d	302	struct lttng_ust_event_notifier *event_notifier)
d37ecb3f FD	303	{
	304	ssize_t ret;
	305	size_t content_len;
	306	int iovec_count = 1;
fd17d7ce	307	struct lttng_ust_abi_event_notifier_notification ust_notif = {0};
d37ecb3f FD	308	struct iovec iov[2];
	309
	310	assert(notif);
	311
115db533	312	ust_notif.token = event_notifier->priv->parent.user_token;
d37ecb3f	313
d8d2416d	314	/*
d37ecb3f FD	315	* Prepare sending the notification from multiple buffers using an
	316	* array of `struct iovec`. The first buffer of the vector is
	317	* notification structure itself and is always present.
d8d2416d	318	*/
d37ecb3f FD	319	iov[0].iov_base = &ust_notif;
	320	iov[0].iov_len = sizeof(ust_notif);
	321
	322	if (notif->has_captures) {
	323	/*
	324	* If captures were requested, the second buffer of the array
	325	* is the capture buffer.
	326	*/
	327	assert(notif->writer.buffer);
	328	content_len = notif->writer.write_pos - notif->writer.buffer;
d8d2416d	329
d37ecb3f	330	assert(content_len > 0 && content_len <= CAPTURE_BUFFER_SIZE);
d8d2416d	331
d37ecb3f FD	332	iov[1].iov_base = notif->capture_buf;
	333	iov[1].iov_len = content_len;
	334
	335	iovec_count++;
	336	} else {
	337	content_len = 0;
	338	}
	339
	340	/*
	341	* Update the capture buffer size so that receiver of the buffer will
	342	* know how much to expect.
	343	*/
	344	ust_notif.capture_buf_size = content_len;
d8d2416d	345
d37ecb3f	346	/* Send all the buffers. */
516d12da	347	ret = ust_patient_writev(notif->notification_fd, iov, iovec_count);
d8d2416d FD	348	if (ret == -1) {
d8d2416d FD	349	if (errno == EAGAIN) {
6566528b FD	350	record_error(event_notifier);
6566528b FD	351	DBG("Cannot send event_notifier notification without blocking: %s",
d8d2416d FD	352	strerror(errno));
	353	} else {
	354	DBG("Error to sending event notifier notification: %s",
	355	strerror(errno));
	356	abort();
	357	}
	358	}
	359	}
d37ecb3f	360
6566528b	361	void lttng_event_notifier_notification_send(
d7d45c0d	362	struct lttng_ust_event_notifier *event_notifier,
a2e4d05e MD	363	const char *stack_data,
a2e4d05e MD	364	struct lttng_ust_notification_ctx *notif_ctx)
d37ecb3f FD	365	{
	366	/*
	367	* This function is called from the probe, we must do dynamic
	368	* allocation in this context.
	369	*/
	370	struct lttng_event_notifier_notification notif = {0};
	371
	372	notification_init(&notif, event_notifier);
	373
a2e4d05e	374	if (caa_unlikely(notif_ctx->eval_capture)) {
5469a374	375	struct lttng_ust_bytecode_runtime *capture_bc_runtime;
d37ecb3f FD	376
	377	/*
	378	* Iterate over all the capture bytecodes. If the interpreter
	379	* functions returns successfully, append the value of the
	380	* `output` parameter to the capture buffer. If the interpreter
	381	* fails, append an empty capture to the buffer.
	382	*/
a2e4d05e MD	383	cds_list_for_each_entry_rcu(capture_bc_runtime,
a2e4d05e MD	384	&event_notifier->priv->capture_bytecode_runtime_head, node) {
d37ecb3f FD	385	struct lttng_interpreter_output output;
d37ecb3f FD	386
22c30e27 MD	387	if (capture_bc_runtime->interpreter_func(capture_bc_runtime,
22c30e27 MD	388	stack_data, &output) == LTTNG_UST_BYTECODE_INTERPRETER_OK)
d37ecb3f FD	389	notification_append_capture(&notif, &output);
	390	else
	391	notification_append_empty_capture(&notif);
	392	}
	393	}
	394
	395	/*
	396	* Send the notification (including the capture buffer) to the
	397	* sessiond.
	398	*/
6566528b	399	notification_send(&notif, event_notifier);
d37ecb3f	400	}