[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 <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>
f03092d7	11	#include <lttng/ust-endian.h>
d8d2416d	12	#include <usterr-signal-safe.h>
a2e4d05e	13	#include <urcu/rculist.h>
d8d2416d	14
bb7ad29d	15	#include "ust-events-internal.h"
b9f82a28 FD	16	#include "../libmsgpack/msgpack.h"
b9f82a28 FD	17	#include "lttng-bytecode.h"
864a1eda	18	#include "ust-share.h"
d8d2416d	19
d37ecb3f FD	20	/*
	21	* We want this write to be atomic AND non-blocking, meaning that we
	22	* want to write either everything OR nothing.
	23	* According to `pipe(7)`, writes that are less than `PIPE_BUF` bytes must be
	24	* atomic, so we bound the capture buffer size to the `PIPE_BUF` minus the size
	25	* of the notification struct we are sending alongside the capture buffer.
	26	*/
	27	#define CAPTURE_BUFFER_SIZE \
fd17d7ce	28	(PIPE_BUF - sizeof(struct lttng_ust_abi_event_notifier_notification) - 1)
d37ecb3f FD	29
	30	struct lttng_event_notifier_notification {
	31	int notification_fd;
	32	uint64_t event_notifier_token;
	33	uint8_t capture_buf[CAPTURE_BUFFER_SIZE];
	34	struct lttng_msgpack_writer writer;
	35	bool has_captures;
	36	};
	37
b9f82a28 FD	38	static
	39	void capture_enum(struct lttng_msgpack_writer *writer,
	40	struct lttng_interpreter_output *output)
	41	{
	42	lttng_msgpack_begin_map(writer, 2);
	43	lttng_msgpack_write_str(writer, "type");
	44	lttng_msgpack_write_str(writer, "enum");
	45
	46	lttng_msgpack_write_str(writer, "value");
	47
	48	switch (output->type) {
	49	case LTTNG_INTERPRETER_TYPE_SIGNED_ENUM:
	50	lttng_msgpack_write_signed_integer(writer, output->u.s);
	51	break;
	52	case LTTNG_INTERPRETER_TYPE_UNSIGNED_ENUM:
	53	lttng_msgpack_write_signed_integer(writer, output->u.u);
	54	break;
	55	default:
	56	abort();
	57	}
	58
	59	lttng_msgpack_end_map(writer);
	60	}
	61
	62	static
	63	int64_t capture_sequence_element_signed(uint8_t *ptr,
a084756d	64	struct lttng_ust_type_integer *integer_type)
b9f82a28 FD	65	{
b9f82a28 FD	66	int64_t value;
a084756d MD	67	unsigned int size = integer_type->size;
a084756d MD	68	bool byte_order_reversed = integer_type->reverse_byte_order;
b9f82a28 FD	69
	70	switch (size) {
	71	case 8:
	72	value = *ptr;
	73	break;
	74	case 16:
	75	{
	76	int16_t tmp;
	77	tmp = (int16_t ) ptr;
	78	if (byte_order_reversed)
	79	tmp = bswap_16(tmp);
	80
	81	value = tmp;
	82	break;
	83	}
	84	case 32:
	85	{
	86	int32_t tmp;
	87	tmp = (int32_t ) ptr;
	88	if (byte_order_reversed)
	89	tmp = bswap_32(tmp);
	90
	91	value = tmp;
	92	break;
	93	}
	94	case 64:
	95	{
	96	int64_t tmp;
	97	tmp = (int64_t ) ptr;
	98	if (byte_order_reversed)
	99	tmp = bswap_64(tmp);
	100
	101	value = tmp;
	102	break;
	103	}
	104	default:
	105	abort();
	106	}
	107
	108	return value;
	109	}
	110
	111	static
	112	uint64_t capture_sequence_element_unsigned(uint8_t *ptr,
a084756d	113	struct lttng_ust_type_integer *integer_type)
b9f82a28 FD	114	{
b9f82a28 FD	115	uint64_t value;
a084756d MD	116	unsigned int size = integer_type->size;
a084756d MD	117	bool byte_order_reversed = integer_type->reverse_byte_order;
b9f82a28 FD	118
	119	switch (size) {
	120	case 8:
	121	value = *ptr;
	122	break;
	123	case 16:
	124	{
	125	uint16_t tmp;
	126	tmp = (uint16_t ) ptr;
	127	if (byte_order_reversed)
	128	tmp = bswap_16(tmp);
	129
	130	value = tmp;
	131	break;
	132	}
	133	case 32:
	134	{
	135	uint32_t tmp;
	136	tmp = (uint32_t ) ptr;
	137	if (byte_order_reversed)
	138	tmp = bswap_32(tmp);
	139
	140	value = tmp;
	141	break;
	142	}
	143	case 64:
	144	{
	145	uint64_t tmp;
	146	tmp = (uint64_t ) ptr;
	147	if (byte_order_reversed)
	148	tmp = bswap_64(tmp);
	149
	150	value = tmp;
	151	break;
	152	}
	153	default:
	154	abort();
	155	}
	156
	157	return value;
	158	}
	159
b9f82a28 FD	160	static
	161	void capture_sequence(struct lttng_msgpack_writer *writer,
	162	struct lttng_interpreter_output *output)
	163	{
a084756d MD	164	struct lttng_ust_type_integer *integer_type;
a084756d MD	165	struct lttng_ust_type_common *nested_type;
b9f82a28 FD	166	uint8_t *ptr;
	167	bool signedness;
	168	int i;
	169
	170	lttng_msgpack_begin_array(writer, output->u.sequence.nr_elem);
	171
	172	ptr = (uint8_t *) output->u.sequence.ptr;
	173	nested_type = output->u.sequence.nested_type;
a084756d MD	174	switch (nested_type->type) {
	175	case lttng_ust_type_integer:
	176	integer_type = lttng_ust_get_type_integer(nested_type);
b9f82a28	177	break;
a084756d	178	case lttng_ust_type_enum:
b9f82a28	179	/* Treat enumeration as an integer. */
a084756d	180	integer_type = lttng_ust_get_type_integer(lttng_ust_get_type_enum(nested_type)->container_type);
b9f82a28 FD	181	break;
	182	default:
	183	/* Capture of array of non-integer are not supported. */
	184	abort();
	185	}
	186	signedness = integer_type->signedness;
	187	for (i = 0; i < output->u.sequence.nr_elem; i++) {
	188	if (signedness) {
	189	lttng_msgpack_write_signed_integer(writer,
	190	capture_sequence_element_signed(ptr, integer_type));
	191	} else {
	192	lttng_msgpack_write_unsigned_integer(writer,
	193	capture_sequence_element_unsigned(ptr, integer_type));
	194	}
	195
	196	/*
	197	* We assume that alignment is smaller or equal to the size.
	198	* This currently holds true but if it changes in the future,
	199	* we will want to change the pointer arithmetics below to
	200	* take into account that the next element might be further
	201	* away.
	202	*/
	203	assert(integer_type->alignment <= integer_type->size);
	204
	205	/* Size is in number of bits. */
	206	ptr += (integer_type->size / CHAR_BIT) ;
	207	}
	208
	209	lttng_msgpack_end_array(writer);
	210	}
	211
d37ecb3f FD	212	static
d37ecb3f FD	213	void notification_init(struct lttng_event_notifier_notification *notif,
d7d45c0d	214	struct lttng_ust_event_notifier *event_notifier)
d8d2416d	215	{
d37ecb3f FD	216	struct lttng_msgpack_writer *writer = &notif->writer;
d37ecb3f FD	217
115db533 MD	218	notif->event_notifier_token = event_notifier->priv->parent.user_token;
115db533 MD	219	notif->notification_fd = event_notifier->priv->group->notification_fd;
d37ecb3f FD	220	notif->has_captures = false;
d37ecb3f FD	221
115db533	222	if (event_notifier->priv->num_captures > 0) {
d37ecb3f FD	223	lttng_msgpack_writer_init(writer, notif->capture_buf,
	224	CAPTURE_BUFFER_SIZE);
	225
115db533	226	lttng_msgpack_begin_array(writer, event_notifier->priv->num_captures);
d37ecb3f FD	227	notif->has_captures = true;
	228	}
	229	}
	230
	231	static
	232	void notification_append_capture(
	233	struct lttng_event_notifier_notification *notif,
	234	struct lttng_interpreter_output *output)
	235	{
	236	struct lttng_msgpack_writer *writer = &notif->writer;
	237
	238	switch (output->type) {
	239	case LTTNG_INTERPRETER_TYPE_S64:
	240	lttng_msgpack_write_signed_integer(writer, output->u.s);
	241	break;
	242	case LTTNG_INTERPRETER_TYPE_U64:
	243	lttng_msgpack_write_unsigned_integer(writer, output->u.u);
	244	break;
	245	case LTTNG_INTERPRETER_TYPE_DOUBLE:
	246	lttng_msgpack_write_double(writer, output->u.d);
	247	break;
	248	case LTTNG_INTERPRETER_TYPE_STRING:
	249	lttng_msgpack_write_str(writer, output->u.str.str);
	250	break;
	251	case LTTNG_INTERPRETER_TYPE_SEQUENCE:
	252	capture_sequence(writer, output);
	253	break;
	254	case LTTNG_INTERPRETER_TYPE_SIGNED_ENUM:
	255	case LTTNG_INTERPRETER_TYPE_UNSIGNED_ENUM:
	256	capture_enum(writer, output);
	257	break;
	258	default:
	259	abort();
	260	}
	261	}
	262
	263	static
	264	void notification_append_empty_capture(
	265	struct lttng_event_notifier_notification *notif)
	266	{
	267	lttng_msgpack_write_nil(&notif->writer);
	268	}
	269
d7d45c0d	270	static void record_error(struct lttng_ust_event_notifier *event_notifier)
6566528b FD	271	{
6566528b FD	272	struct lttng_event_notifier_group *event_notifier_group =
115db533	273	event_notifier->priv->group;
33f43caa	274	struct lttng_counter *error_counter;
6566528b FD	275	size_t dimension_index[1];
	276	int ret;
	277
33f43caa MD	278	error_counter = CMM_LOAD_SHARED(event_notifier_group->error_counter);
	279	/*
	280	* load-acquire paired with store-release orders creation of the
	281	* error counter and setting error_counter_len before the
	282	* error_counter is used.
	283	* Currently a full memory barrier is used, which could be
	284	* turned into acquire-release barriers.
	285	*/
	286	cmm_smp_mb();
c30ad764	287	/* This group may not have an error counter attached to it. */
33f43caa	288	if (!error_counter)
c30ad764 MD	289	return;
c30ad764 MD	290
115db533	291	dimension_index[0] = event_notifier->priv->error_counter_index;
6566528b	292	ret = event_notifier_group->error_counter->ops->counter_add(
33f43caa	293	error_counter->counter, dimension_index, 1);
6566528b FD	294	if (ret)
	295	WARN_ON_ONCE(1);
	296	}
	297
d37ecb3f	298	static
6566528b	299	void notification_send(struct lttng_event_notifier_notification *notif,
d7d45c0d	300	struct lttng_ust_event_notifier *event_notifier)
d37ecb3f FD	301	{
	302	ssize_t ret;
	303	size_t content_len;
	304	int iovec_count = 1;
fd17d7ce	305	struct lttng_ust_abi_event_notifier_notification ust_notif = {0};
d37ecb3f FD	306	struct iovec iov[2];
	307
	308	assert(notif);
	309
115db533	310	ust_notif.token = event_notifier->priv->parent.user_token;
d37ecb3f	311
d8d2416d	312	/*
d37ecb3f FD	313	* Prepare sending the notification from multiple buffers using an
	314	* array of `struct iovec`. The first buffer of the vector is
	315	* notification structure itself and is always present.
d8d2416d	316	*/
d37ecb3f FD	317	iov[0].iov_base = &ust_notif;
	318	iov[0].iov_len = sizeof(ust_notif);
	319
	320	if (notif->has_captures) {
	321	/*
	322	* If captures were requested, the second buffer of the array
	323	* is the capture buffer.
	324	*/
	325	assert(notif->writer.buffer);
	326	content_len = notif->writer.write_pos - notif->writer.buffer;
d8d2416d	327
d37ecb3f	328	assert(content_len > 0 && content_len <= CAPTURE_BUFFER_SIZE);
d8d2416d	329
d37ecb3f FD	330	iov[1].iov_base = notif->capture_buf;
	331	iov[1].iov_len = content_len;
	332
	333	iovec_count++;
	334	} else {
	335	content_len = 0;
	336	}
	337
	338	/*
	339	* Update the capture buffer size so that receiver of the buffer will
	340	* know how much to expect.
	341	*/
	342	ust_notif.capture_buf_size = content_len;
d8d2416d	343
d37ecb3f	344	/* Send all the buffers. */
516d12da	345	ret = ust_patient_writev(notif->notification_fd, iov, iovec_count);
d8d2416d FD	346	if (ret == -1) {
d8d2416d FD	347	if (errno == EAGAIN) {
6566528b FD	348	record_error(event_notifier);
6566528b FD	349	DBG("Cannot send event_notifier notification without blocking: %s",
d8d2416d FD	350	strerror(errno));
	351	} else {
	352	DBG("Error to sending event notifier notification: %s",
	353	strerror(errno));
	354	abort();
	355	}
	356	}
	357	}
d37ecb3f	358
6566528b	359	void lttng_event_notifier_notification_send(
d7d45c0d	360	struct lttng_ust_event_notifier *event_notifier,
a2e4d05e MD	361	const char *stack_data,
a2e4d05e MD	362	struct lttng_ust_notification_ctx *notif_ctx)
d37ecb3f FD	363	{
	364	/*
	365	* This function is called from the probe, we must do dynamic
	366	* allocation in this context.
	367	*/
	368	struct lttng_event_notifier_notification notif = {0};
	369
	370	notification_init(&notif, event_notifier);
	371
a2e4d05e	372	if (caa_unlikely(notif_ctx->eval_capture)) {
5469a374	373	struct lttng_ust_bytecode_runtime *capture_bc_runtime;
d37ecb3f FD	374
	375	/*
	376	* Iterate over all the capture bytecodes. If the interpreter
	377	* functions returns successfully, append the value of the
	378	* `output` parameter to the capture buffer. If the interpreter
	379	* fails, append an empty capture to the buffer.
	380	*/
a2e4d05e MD	381	cds_list_for_each_entry_rcu(capture_bc_runtime,
a2e4d05e MD	382	&event_notifier->priv->capture_bytecode_runtime_head, node) {
d37ecb3f FD	383	struct lttng_interpreter_output output;
d37ecb3f FD	384
22c30e27 MD	385	if (capture_bc_runtime->interpreter_func(capture_bc_runtime,
22c30e27 MD	386	stack_data, &output) == LTTNG_UST_BYTECODE_INTERPRETER_OK)
d37ecb3f FD	387	notification_append_capture(&notif, &output);
	388	else
	389	notification_append_empty_capture(&notif);
	390	}
	391	}
	392
	393	/*
	394	* Send the notification (including the capture buffer) to the
	395	* sessiond.
	396	*/
6566528b	397	notification_send(&notif, event_notifier);
d37ecb3f	398	}