[lttng-tools.git] / src / common / event-rule / kernel-kprobe.c

/*
 * Copyright (C) 2019 Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
 *
 * SPDX-License-Identifier: LGPL-2.1-only
 *
 */

#include <assert.h>
#include <common/credentials.h>
#include <common/error.h>
#include <common/hashtable/hashtable.h>
#include <common/hashtable/utils.h>
#include <common/macros.h>
#include <common/mi-lttng.h>
#include <common/payload-view.h>
#include <common/payload.h>
#include <common/runas.h>
#include <ctype.h>
#include <lttng/constant.h>
#include <lttng/event-rule/event-rule-internal.h>
#include <lttng/event-rule/event-rule.h>
#include <lttng/event-rule/kernel-kprobe-internal.h>
#include <lttng/kernel-probe-internal.h>
#include <lttng/kernel-probe.h>
#include <stdio.h>

#define IS_KPROBE_EVENT_RULE(rule) \
	(lttng_event_rule_get_type(rule) == LTTNG_EVENT_RULE_TYPE_KERNEL_KPROBE)

#if (LTTNG_SYMBOL_NAME_LEN == 256)
#define LTTNG_SYMBOL_NAME_LEN_SCANF_IS_A_BROKEN_API "255"
#endif

static void lttng_event_rule_kernel_kprobe_destroy(struct lttng_event_rule *rule)
{
	struct lttng_event_rule_kernel_kprobe *kprobe;

	kprobe = container_of(rule, struct lttng_event_rule_kernel_kprobe, parent);

	lttng_kernel_probe_location_destroy(kprobe->location);
	free(kprobe->name);
	free(kprobe);
}

static bool lttng_event_rule_kernel_kprobe_validate(
		const struct lttng_event_rule *rule)
{
	bool valid = false;
	struct lttng_event_rule_kernel_kprobe *kprobe;

	if (!rule) {
		goto end;
	}

	kprobe = container_of(rule, struct lttng_event_rule_kernel_kprobe, parent);

	/* Required field. */
	if (!kprobe->name) {
		ERR("Invalid name event rule: a name must be set.");
		goto end;
	}

	/* Required field. */
	if(!kprobe->location) {
		ERR("Invalid name event rule: a location must be set.");
		goto end;
	}

	valid = true;
end:
	return valid;
}

static int lttng_event_rule_kernel_kprobe_serialize(
		const struct lttng_event_rule *rule,
		struct lttng_payload *payload)
{
	int ret;
	size_t name_len, header_offset, size_before_location;
	struct lttng_event_rule_kernel_kprobe *kprobe;
	struct lttng_event_rule_kernel_kprobe_comm kprobe_comm;
	struct lttng_event_rule_kernel_kprobe_comm *header;

	if (!rule || !IS_KPROBE_EVENT_RULE(rule)) {
		ret = -1;
		goto end;
	}

	header_offset = payload->buffer.size;

	DBG("Serializing kprobe event rule.");
	kprobe = container_of(rule, struct lttng_event_rule_kernel_kprobe, parent);

	name_len = strlen(kprobe->name) + 1;
	kprobe_comm.name_len = name_len;

	ret = lttng_dynamic_buffer_append(
			&payload->buffer, &kprobe_comm, sizeof(kprobe_comm));
	if (ret) {
		goto end;
	}

	ret = lttng_dynamic_buffer_append(&payload->buffer, kprobe->name, name_len);
	if (ret) {
		goto end;
	}

	size_before_location = payload->buffer.size;

	ret = lttng_kernel_probe_location_serialize(kprobe->location, payload);
	if (ret < 0) {
		goto end;
	}

	/* Update the header regarding the probe size. */
	header = (struct lttng_event_rule_kernel_kprobe_comm*) (
			(char *) payload->buffer.data + header_offset);
	header->location_len = payload->buffer.size - size_before_location;

	ret = 0;

end:
	return ret;
}

static bool lttng_event_rule_kernel_kprobe_is_equal(const struct lttng_event_rule *_a,
		const struct lttng_event_rule *_b)
{
	bool is_equal = false;
	struct lttng_event_rule_kernel_kprobe *a, *b;

	a = container_of(_a, struct lttng_event_rule_kernel_kprobe, parent);
	b = container_of(_b, struct lttng_event_rule_kernel_kprobe, parent);

	/* Quick checks */
	if (!!a->name != !!b->name) {
		goto end;
	}

	/* Long check */
	assert(a->name);
	assert(b->name);
	if (strcmp(a->name, b->name)) {
		goto end;
	}

	is_equal = lttng_kernel_probe_location_is_equal(
			a->location, b->location);
end:
	return is_equal;
}

static enum lttng_error_code lttng_event_rule_kernel_kprobe_generate_filter_bytecode(
		struct lttng_event_rule *rule,
		const struct lttng_credentials *creds)
{
	/* Nothing to do. */
	return LTTNG_OK;
}

static const char *lttng_event_rule_kernel_kprobe_get_filter(
		const struct lttng_event_rule *rule)
{
	/* Not supported. */
	return NULL;
}

static const struct lttng_bytecode *
lttng_event_rule_kernel_kprobe_get_filter_bytecode(const struct lttng_event_rule *rule)
{
	/* Not supported. */
	return NULL;
}

static enum lttng_event_rule_generate_exclusions_status
lttng_event_rule_kernel_kprobe_generate_exclusions(const struct lttng_event_rule *rule,
		struct lttng_event_exclusion **exclusions)
{
	/* Not supported. */
	*exclusions = NULL;
	return LTTNG_EVENT_RULE_GENERATE_EXCLUSIONS_STATUS_NONE;
}

static unsigned long
lttng_event_rule_kernel_kprobe_hash(
		const struct lttng_event_rule *rule)
{
	unsigned long hash;
	struct lttng_event_rule_kernel_kprobe *krule =
			container_of(rule, typeof(*krule), parent);

	hash = hash_key_ulong((void *) LTTNG_EVENT_RULE_TYPE_KERNEL_KPROBE,
			lttng_ht_seed);
	hash ^= hash_key_str(krule->name, lttng_ht_seed);
	hash ^= lttng_kernel_probe_location_hash(krule->location);

	return hash;
}

static
int kernel_probe_set_location(
		struct lttng_event_rule_kernel_kprobe *kprobe,
		const struct lttng_kernel_probe_location *location)
{
	int ret;
	struct lttng_kernel_probe_location *location_copy = NULL;

	if (!kprobe || !location || kprobe->location) {
		ret = -1;
		goto end;
	}

	location_copy = lttng_kernel_probe_location_copy(location);
	if (!location_copy) {
		ret = -1;
		goto end;
	}

	kprobe->location = location_copy;
	location_copy = NULL;
	ret = 0;
end:
	lttng_kernel_probe_location_destroy(location_copy);
	return ret;
}

static
enum lttng_error_code lttng_event_rule_kernel_kprobe_mi_serialize(
		const struct lttng_event_rule *rule, struct mi_writer *writer)
{
	int ret;
	enum lttng_error_code ret_code;
	enum lttng_event_rule_status status;
	const char *event_name = NULL;
	const struct lttng_kernel_probe_location *location = NULL;

	assert(rule);
	assert(writer);
	assert(IS_KPROBE_EVENT_RULE(rule));

	status = lttng_event_rule_kernel_kprobe_get_event_name(
			rule, &event_name);
	assert(status == LTTNG_EVENT_RULE_STATUS_OK);
	assert(event_name);

	status = lttng_event_rule_kernel_kprobe_get_location(rule, &location);
	assert(status == LTTNG_EVENT_RULE_STATUS_OK);
	assert(location);

	/* Open event rule kernel kprobe element. */
	ret = mi_lttng_writer_open_element(
			writer, mi_lttng_element_event_rule_kernel_kprobe);
	if (ret) {
		goto mi_error;
	}

	/* Name. */
	ret = mi_lttng_writer_write_element_string(writer,
			mi_lttng_element_event_rule_event_name, event_name);
	if (ret) {
		goto mi_error;
	}

	/* Probe location. */
	ret_code = lttng_kernel_probe_location_mi_serialize(location, writer);
	if (ret_code != LTTNG_OK) {
		goto end;
	}

	/* Close event rule kernel kprobe element. */
	ret = mi_lttng_writer_close_element(writer);
	if (ret) {
		goto mi_error;
	}

	ret_code = LTTNG_OK;
	goto end;

mi_error:
	ret_code = LTTNG_ERR_MI_IO_FAIL;
end:
	return ret_code;
}

struct lttng_event_rule *lttng_event_rule_kernel_kprobe_create(
		const struct lttng_kernel_probe_location *location)
{
	struct lttng_event_rule *rule = NULL;
	struct lttng_event_rule_kernel_kprobe *krule;

	krule = zmalloc(sizeof(struct lttng_event_rule_kernel_kprobe));
	if (!krule) {
		goto end;
	}

	rule = &krule->parent;
	lttng_event_rule_init(&krule->parent, LTTNG_EVENT_RULE_TYPE_KERNEL_KPROBE);
	krule->parent.validate = lttng_event_rule_kernel_kprobe_validate;
	krule->parent.serialize = lttng_event_rule_kernel_kprobe_serialize;
	krule->parent.equal = lttng_event_rule_kernel_kprobe_is_equal;
	krule->parent.destroy = lttng_event_rule_kernel_kprobe_destroy;
	krule->parent.generate_filter_bytecode =
			lttng_event_rule_kernel_kprobe_generate_filter_bytecode;
	krule->parent.get_filter = lttng_event_rule_kernel_kprobe_get_filter;
	krule->parent.get_filter_bytecode =
			lttng_event_rule_kernel_kprobe_get_filter_bytecode;
	krule->parent.generate_exclusions =
			lttng_event_rule_kernel_kprobe_generate_exclusions;
	krule->parent.hash = lttng_event_rule_kernel_kprobe_hash;
	krule->parent.mi_serialize = lttng_event_rule_kernel_kprobe_mi_serialize;

	if (kernel_probe_set_location(krule, location)) {
		lttng_event_rule_destroy(rule);
		rule = NULL;
	}

end:
	return rule;
}

LTTNG_HIDDEN
ssize_t lttng_event_rule_kernel_kprobe_create_from_payload(
		struct lttng_payload_view *view,
		struct lttng_event_rule **_event_rule)
{
	ssize_t ret, offset = 0;
	enum lttng_event_rule_status status;
	const struct lttng_event_rule_kernel_kprobe_comm *kprobe_comm;
	const char *name;
	struct lttng_buffer_view current_buffer_view;
	struct lttng_event_rule *rule = NULL;
	struct lttng_kernel_probe_location *location = NULL;

	if (!_event_rule) {
		ret = -1;
		goto end;
	}

	current_buffer_view = lttng_buffer_view_from_view(
			&view->buffer, offset, sizeof(*kprobe_comm));
	if (!lttng_buffer_view_is_valid(&current_buffer_view)) {
		ERR("Failed to initialize from malformed event rule kprobe: buffer too short to contain header.");
		ret = -1;
		goto end;
	}

	kprobe_comm = (typeof(kprobe_comm)) current_buffer_view.data;

	/* Skip to payload */
	offset += current_buffer_view.size;

	{
		/* Map the name. */
		struct lttng_payload_view current_payload_view =
				lttng_payload_view_from_view(view, offset,
						kprobe_comm->name_len);

		if (!lttng_payload_view_is_valid(&current_payload_view)) {
			ret = -1;
			goto end;
		}

		name = current_payload_view.buffer.data;
		if (!lttng_buffer_view_contains_string(
				&current_payload_view.buffer, name,
				kprobe_comm->name_len)) {
			ret = -1;
			goto end;
		}
	}

	/* Skip after the name. */
	offset += kprobe_comm->name_len;

	/* Map the kernel probe location. */
	{
		struct lttng_payload_view current_payload_view =
				lttng_payload_view_from_view(view, offset,
						kprobe_comm->location_len);

		if (!lttng_payload_view_is_valid(&current_payload_view)) {
			ret = -1;
			goto end;
		}

		ret = lttng_kernel_probe_location_create_from_payload(
				&current_payload_view, &location);
		if (ret < 0) {
			ret = -1;
			goto end;
		}
	}

	if (ret != kprobe_comm->location_len) {
		ret = -1;
		goto end;
	}

	/* Skip after the location */
	offset += kprobe_comm->location_len;

	rule = lttng_event_rule_kernel_kprobe_create(location);
	if (!rule) {
		ERR("Failed to create event rule kprobe.");
		ret = -1;
		goto end;
	}

	status = lttng_event_rule_kernel_kprobe_set_event_name(rule, name);
	if (status != LTTNG_EVENT_RULE_STATUS_OK) {
		ERR("Failed to set event rule kprobe name.");
		ret = -1;
		goto end;
	}

	*_event_rule = rule;
	rule = NULL;
	ret = offset;
end:
	lttng_kernel_probe_location_destroy(location);
	lttng_event_rule_destroy(rule);
	return ret;
}

enum lttng_event_rule_status lttng_event_rule_kernel_kprobe_get_location(
		const struct lttng_event_rule *rule,
		const struct lttng_kernel_probe_location **location)
{
	enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK;
	struct lttng_event_rule_kernel_kprobe *kprobe;

	if (!rule || !IS_KPROBE_EVENT_RULE(rule) || !location) {
		status = LTTNG_EVENT_RULE_STATUS_INVALID;
		goto end;
	}

	kprobe = container_of(rule, struct lttng_event_rule_kernel_kprobe, parent);
	*location = kprobe->location;

	if (!*location) {
		status = LTTNG_EVENT_RULE_STATUS_UNSET;
		goto end;
	}

end:
	return status;
}

enum lttng_event_rule_status lttng_event_rule_kernel_kprobe_set_event_name(
		struct lttng_event_rule *rule, const char *name)
{
	char *name_copy = NULL;
	struct lttng_event_rule_kernel_kprobe *kprobe;
	enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK;

	if (!rule || !IS_KPROBE_EVENT_RULE(rule) || !name ||
			strlen(name) == 0) {
		status = LTTNG_EVENT_RULE_STATUS_INVALID;
		goto end;
	}

	kprobe = container_of(rule, struct lttng_event_rule_kernel_kprobe, parent);
	name_copy = strdup(name);
	if (!name_copy) {
		status = LTTNG_EVENT_RULE_STATUS_ERROR;
		goto end;
	}

	free(kprobe->name);

	kprobe->name = name_copy;
	name_copy = NULL;
end:
	return status;
}

enum lttng_event_rule_status lttng_event_rule_kernel_kprobe_get_event_name(
		const struct lttng_event_rule *rule, const char **name)
{
	struct lttng_event_rule_kernel_kprobe *kprobe;
	enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK;

	if (!rule || !IS_KPROBE_EVENT_RULE(rule) || !name) {
		status = LTTNG_EVENT_RULE_STATUS_INVALID;
		goto end;
	}

	kprobe = container_of(rule, struct lttng_event_rule_kernel_kprobe, parent);
	if (!kprobe->name) {
		status = LTTNG_EVENT_RULE_STATUS_UNSET;
		goto end;
	}

	*name = kprobe->name;
end:
	return status;
}
Commit	Line	Data
	1	/*
	2	* Copyright (C) 2019 Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
	3	*
	4	* SPDX-License-Identifier: LGPL-2.1-only
	5	*
	6	*/
	7
	8	#include <assert.h>
	9	#include <common/credentials.h>
	10	#include <common/error.h>
	11	#include <common/hashtable/hashtable.h>
	12	#include <common/hashtable/utils.h>
	13	#include <common/macros.h>
	14	#include <common/mi-lttng.h>
	15	#include <common/payload-view.h>
	16	#include <common/payload.h>
	17	#include <common/runas.h>
	18	#include <ctype.h>
	19	#include <lttng/constant.h>
	20	#include <lttng/event-rule/event-rule-internal.h>
	21	#include <lttng/event-rule/event-rule.h>
	22	#include <lttng/event-rule/kernel-kprobe-internal.h>
	23	#include <lttng/kernel-probe-internal.h>
	24	#include <lttng/kernel-probe.h>
	25	#include <stdio.h>
	26
	27	#define IS_KPROBE_EVENT_RULE(rule) \
	28	(lttng_event_rule_get_type(rule) == LTTNG_EVENT_RULE_TYPE_KERNEL_KPROBE)
	29
	30	#if (LTTNG_SYMBOL_NAME_LEN == 256)
	31	#define LTTNG_SYMBOL_NAME_LEN_SCANF_IS_A_BROKEN_API "255"
	32	#endif
	33
	34	static void lttng_event_rule_kernel_kprobe_destroy(struct lttng_event_rule *rule)
	35	{
	36	struct lttng_event_rule_kernel_kprobe *kprobe;
	37
	38	kprobe = container_of(rule, struct lttng_event_rule_kernel_kprobe, parent);
	39
	40	lttng_kernel_probe_location_destroy(kprobe->location);
	41	free(kprobe->name);
	42	free(kprobe);
	43	}
	44
	45	static bool lttng_event_rule_kernel_kprobe_validate(
	46	const struct lttng_event_rule *rule)
	47	{
	48	bool valid = false;
	49	struct lttng_event_rule_kernel_kprobe *kprobe;
	50
	51	if (!rule) {
	52	goto end;
	53	}
	54
	55	kprobe = container_of(rule, struct lttng_event_rule_kernel_kprobe, parent);
	56
	57	/* Required field. */
	58	if (!kprobe->name) {
	59	ERR("Invalid name event rule: a name must be set.");
	60	goto end;
	61	}
	62
	63	/* Required field. */
	64	if(!kprobe->location) {
	65	ERR("Invalid name event rule: a location must be set.");
	66	goto end;
	67	}
	68
	69	valid = true;
	70	end:
	71	return valid;
	72	}
	73
	74	static int lttng_event_rule_kernel_kprobe_serialize(
	75	const struct lttng_event_rule *rule,
	76	struct lttng_payload *payload)
	77	{
	78	int ret;
	79	size_t name_len, header_offset, size_before_location;
	80	struct lttng_event_rule_kernel_kprobe *kprobe;
	81	struct lttng_event_rule_kernel_kprobe_comm kprobe_comm;
	82	struct lttng_event_rule_kernel_kprobe_comm *header;
	83
	84	if (!rule \|\| !IS_KPROBE_EVENT_RULE(rule)) {
	85	ret = -1;
	86	goto end;
	87	}
	88
	89	header_offset = payload->buffer.size;
	90
	91	DBG("Serializing kprobe event rule.");
	92	kprobe = container_of(rule, struct lttng_event_rule_kernel_kprobe, parent);
	93
	94	name_len = strlen(kprobe->name) + 1;
	95	kprobe_comm.name_len = name_len;
	96
	97	ret = lttng_dynamic_buffer_append(
	98	&payload->buffer, &kprobe_comm, sizeof(kprobe_comm));
	99	if (ret) {
	100	goto end;
	101	}
	102
	103	ret = lttng_dynamic_buffer_append(&payload->buffer, kprobe->name, name_len);
	104	if (ret) {
	105	goto end;
	106	}
	107
	108	size_before_location = payload->buffer.size;
	109
	110	ret = lttng_kernel_probe_location_serialize(kprobe->location, payload);
	111	if (ret < 0) {
	112	goto end;
	113	}
	114
	115	/* Update the header regarding the probe size. */
	116	header = (struct lttng_event_rule_kernel_kprobe_comm*) (
	117	(char *) payload->buffer.data + header_offset);
	118	header->location_len = payload->buffer.size - size_before_location;
	119
	120	ret = 0;
	121
	122	end:
	123	return ret;
	124	}
	125
	126	static bool lttng_event_rule_kernel_kprobe_is_equal(const struct lttng_event_rule *_a,
	127	const struct lttng_event_rule *_b)
	128	{
	129	bool is_equal = false;
	130	struct lttng_event_rule_kernel_kprobe a, b;
	131
	132	a = container_of(_a, struct lttng_event_rule_kernel_kprobe, parent);
	133	b = container_of(_b, struct lttng_event_rule_kernel_kprobe, parent);
	134
	135	/* Quick checks */
	136	if (!!a->name != !!b->name) {
	137	goto end;
	138	}
	139
	140	/* Long check */
	141	assert(a->name);
	142	assert(b->name);
	143	if (strcmp(a->name, b->name)) {
	144	goto end;
	145	}
	146
	147	is_equal = lttng_kernel_probe_location_is_equal(
	148	a->location, b->location);
	149	end:
	150	return is_equal;
	151	}
	152
	153	static enum lttng_error_code lttng_event_rule_kernel_kprobe_generate_filter_bytecode(
	154	struct lttng_event_rule *rule,
	155	const struct lttng_credentials *creds)
	156	{
	157	/* Nothing to do. */
	158	return LTTNG_OK;
	159	}
	160
	161	static const char *lttng_event_rule_kernel_kprobe_get_filter(
	162	const struct lttng_event_rule *rule)
	163	{
	164	/* Not supported. */
	165	return NULL;
	166	}
	167
	168	static const struct lttng_bytecode *
	169	lttng_event_rule_kernel_kprobe_get_filter_bytecode(const struct lttng_event_rule *rule)
	170	{
	171	/* Not supported. */
	172	return NULL;
	173	}
	174
	175	static enum lttng_event_rule_generate_exclusions_status
	176	lttng_event_rule_kernel_kprobe_generate_exclusions(const struct lttng_event_rule *rule,
	177	struct lttng_event_exclusion **exclusions)
	178	{
	179	/* Not supported. */
	180	*exclusions = NULL;
	181	return LTTNG_EVENT_RULE_GENERATE_EXCLUSIONS_STATUS_NONE;
	182	}
	183
	184	static unsigned long
	185	lttng_event_rule_kernel_kprobe_hash(
	186	const struct lttng_event_rule *rule)
	187	{
	188	unsigned long hash;
	189	struct lttng_event_rule_kernel_kprobe *krule =
	190	container_of(rule, typeof(*krule), parent);
	191
	192	hash = hash_key_ulong((void *) LTTNG_EVENT_RULE_TYPE_KERNEL_KPROBE,
	193	lttng_ht_seed);
	194	hash ^= hash_key_str(krule->name, lttng_ht_seed);
	195	hash ^= lttng_kernel_probe_location_hash(krule->location);
	196
	197	return hash;
	198	}
	199
	200	static
	201	int kernel_probe_set_location(
	202	struct lttng_event_rule_kernel_kprobe *kprobe,
	203	const struct lttng_kernel_probe_location *location)
	204	{
	205	int ret;
	206	struct lttng_kernel_probe_location *location_copy = NULL;
	207
	208	if (!kprobe \|\| !location \|\| kprobe->location) {
	209	ret = -1;
	210	goto end;
	211	}
	212
	213	location_copy = lttng_kernel_probe_location_copy(location);
	214	if (!location_copy) {
	215	ret = -1;
	216	goto end;
	217	}
	218
	219	kprobe->location = location_copy;
	220	location_copy = NULL;
	221	ret = 0;
	222	end:
	223	lttng_kernel_probe_location_destroy(location_copy);
	224	return ret;
	225	}
	226
	227	static
	228	enum lttng_error_code lttng_event_rule_kernel_kprobe_mi_serialize(
	229	const struct lttng_event_rule rule, struct mi_writer writer)
	230	{
	231	int ret;
	232	enum lttng_error_code ret_code;
	233	enum lttng_event_rule_status status;
	234	const char *event_name = NULL;
	235	const struct lttng_kernel_probe_location *location = NULL;
	236
	237	assert(rule);
	238	assert(writer);
	239	assert(IS_KPROBE_EVENT_RULE(rule));
	240
	241	status = lttng_event_rule_kernel_kprobe_get_event_name(
	242	rule, &event_name);
	243	assert(status == LTTNG_EVENT_RULE_STATUS_OK);
	244	assert(event_name);
	245
	246	status = lttng_event_rule_kernel_kprobe_get_location(rule, &location);
	247	assert(status == LTTNG_EVENT_RULE_STATUS_OK);
	248	assert(location);
	249
	250	/* Open event rule kernel kprobe element. */
	251	ret = mi_lttng_writer_open_element(
	252	writer, mi_lttng_element_event_rule_kernel_kprobe);
	253	if (ret) {
	254	goto mi_error;
	255	}
	256
	257	/* Name. */
	258	ret = mi_lttng_writer_write_element_string(writer,
	259	mi_lttng_element_event_rule_event_name, event_name);
	260	if (ret) {
	261	goto mi_error;
	262	}
	263
	264	/* Probe location. */
	265	ret_code = lttng_kernel_probe_location_mi_serialize(location, writer);
	266	if (ret_code != LTTNG_OK) {
	267	goto end;
	268	}
	269
	270	/* Close event rule kernel kprobe element. */
	271	ret = mi_lttng_writer_close_element(writer);
	272	if (ret) {
	273	goto mi_error;
	274	}
	275
	276	ret_code = LTTNG_OK;
	277	goto end;
	278
	279	mi_error:
	280	ret_code = LTTNG_ERR_MI_IO_FAIL;
	281	end:
	282	return ret_code;
	283	}
	284
	285	struct lttng_event_rule *lttng_event_rule_kernel_kprobe_create(
	286	const struct lttng_kernel_probe_location *location)
	287	{
	288	struct lttng_event_rule *rule = NULL;
	289	struct lttng_event_rule_kernel_kprobe *krule;
	290
	291	krule = zmalloc(sizeof(struct lttng_event_rule_kernel_kprobe));
	292	if (!krule) {
	293	goto end;
	294	}
	295
	296	rule = &krule->parent;
	297	lttng_event_rule_init(&krule->parent, LTTNG_EVENT_RULE_TYPE_KERNEL_KPROBE);
	298	krule->parent.validate = lttng_event_rule_kernel_kprobe_validate;
	299	krule->parent.serialize = lttng_event_rule_kernel_kprobe_serialize;
	300	krule->parent.equal = lttng_event_rule_kernel_kprobe_is_equal;
	301	krule->parent.destroy = lttng_event_rule_kernel_kprobe_destroy;
	302	krule->parent.generate_filter_bytecode =
	303	lttng_event_rule_kernel_kprobe_generate_filter_bytecode;
	304	krule->parent.get_filter = lttng_event_rule_kernel_kprobe_get_filter;
	305	krule->parent.get_filter_bytecode =
	306	lttng_event_rule_kernel_kprobe_get_filter_bytecode;
	307	krule->parent.generate_exclusions =
	308	lttng_event_rule_kernel_kprobe_generate_exclusions;
	309	krule->parent.hash = lttng_event_rule_kernel_kprobe_hash;
	310	krule->parent.mi_serialize = lttng_event_rule_kernel_kprobe_mi_serialize;
	311
	312	if (kernel_probe_set_location(krule, location)) {
	313	lttng_event_rule_destroy(rule);
	314	rule = NULL;
	315	}
	316
	317	end:
	318	return rule;
	319	}
	320
	321	LTTNG_HIDDEN
	322	ssize_t lttng_event_rule_kernel_kprobe_create_from_payload(
	323	struct lttng_payload_view *view,
	324	struct lttng_event_rule **_event_rule)
	325	{
	326	ssize_t ret, offset = 0;
	327	enum lttng_event_rule_status status;
	328	const struct lttng_event_rule_kernel_kprobe_comm *kprobe_comm;
	329	const char *name;
	330	struct lttng_buffer_view current_buffer_view;
	331	struct lttng_event_rule *rule = NULL;
	332	struct lttng_kernel_probe_location *location = NULL;
	333
	334	if (!_event_rule) {
	335	ret = -1;
	336	goto end;
	337	}
	338
	339	current_buffer_view = lttng_buffer_view_from_view(
	340	&view->buffer, offset, sizeof(*kprobe_comm));
	341	if (!lttng_buffer_view_is_valid(&current_buffer_view)) {
	342	ERR("Failed to initialize from malformed event rule kprobe: buffer too short to contain header.");
	343	ret = -1;
	344	goto end;
	345	}
	346
	347	kprobe_comm = (typeof(kprobe_comm)) current_buffer_view.data;
	348
	349	/* Skip to payload */
	350	offset += current_buffer_view.size;
	351
	352	{
	353	/* Map the name. */
	354	struct lttng_payload_view current_payload_view =
	355	lttng_payload_view_from_view(view, offset,
	356	kprobe_comm->name_len);
	357
	358	if (!lttng_payload_view_is_valid(&current_payload_view)) {
	359	ret = -1;
	360	goto end;
	361	}
	362
	363	name = current_payload_view.buffer.data;
	364	if (!lttng_buffer_view_contains_string(
	365	&current_payload_view.buffer, name,
	366	kprobe_comm->name_len)) {
	367	ret = -1;
	368	goto end;
	369	}
	370	}
	371
	372	/* Skip after the name. */
	373	offset += kprobe_comm->name_len;
	374
	375	/* Map the kernel probe location. */
	376	{
	377	struct lttng_payload_view current_payload_view =
	378	lttng_payload_view_from_view(view, offset,
	379	kprobe_comm->location_len);
	380
	381	if (!lttng_payload_view_is_valid(&current_payload_view)) {
	382	ret = -1;
	383	goto end;
	384	}
	385
	386	ret = lttng_kernel_probe_location_create_from_payload(
	387	&current_payload_view, &location);
	388	if (ret < 0) {
	389	ret = -1;
	390	goto end;
	391	}
	392	}
	393
	394	if (ret != kprobe_comm->location_len) {
	395	ret = -1;
	396	goto end;
	397	}
	398
	399	/* Skip after the location */
	400	offset += kprobe_comm->location_len;
	401
	402	rule = lttng_event_rule_kernel_kprobe_create(location);
	403	if (!rule) {
	404	ERR("Failed to create event rule kprobe.");
	405	ret = -1;
	406	goto end;
	407	}
	408
	409	status = lttng_event_rule_kernel_kprobe_set_event_name(rule, name);
	410	if (status != LTTNG_EVENT_RULE_STATUS_OK) {
	411	ERR("Failed to set event rule kprobe name.");
	412	ret = -1;
	413	goto end;
	414	}
	415
	416	*_event_rule = rule;
	417	rule = NULL;
	418	ret = offset;
	419	end:
	420	lttng_kernel_probe_location_destroy(location);
	421	lttng_event_rule_destroy(rule);
	422	return ret;
	423	}
	424
	425	enum lttng_event_rule_status lttng_event_rule_kernel_kprobe_get_location(
	426	const struct lttng_event_rule *rule,
	427	const struct lttng_kernel_probe_location **location)
	428	{
	429	enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK;
	430	struct lttng_event_rule_kernel_kprobe *kprobe;
	431
	432	if (!rule \|\| !IS_KPROBE_EVENT_RULE(rule) \|\| !location) {
	433	status = LTTNG_EVENT_RULE_STATUS_INVALID;
	434	goto end;
	435	}
	436
	437	kprobe = container_of(rule, struct lttng_event_rule_kernel_kprobe, parent);
	438	*location = kprobe->location;
	439
	440	if (!*location) {
	441	status = LTTNG_EVENT_RULE_STATUS_UNSET;
	442	goto end;
	443	}
	444
	445	end:
	446	return status;
	447	}
	448
	449	enum lttng_event_rule_status lttng_event_rule_kernel_kprobe_set_event_name(
	450	struct lttng_event_rule rule, const char name)
	451	{
	452	char *name_copy = NULL;
	453	struct lttng_event_rule_kernel_kprobe *kprobe;
	454	enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK;
	455
	456	if (!rule \|\| !IS_KPROBE_EVENT_RULE(rule) \|\| !name \|\|
	457	strlen(name) == 0) {
	458	status = LTTNG_EVENT_RULE_STATUS_INVALID;
	459	goto end;
	460	}
	461
	462	kprobe = container_of(rule, struct lttng_event_rule_kernel_kprobe, parent);
	463	name_copy = strdup(name);
	464	if (!name_copy) {
	465	status = LTTNG_EVENT_RULE_STATUS_ERROR;
	466	goto end;
	467	}
	468
	469	free(kprobe->name);
	470
	471	kprobe->name = name_copy;
	472	name_copy = NULL;
	473	end:
	474	return status;
	475	}
	476
	477	enum lttng_event_rule_status lttng_event_rule_kernel_kprobe_get_event_name(
	478	const struct lttng_event_rule rule, const char *name)
	479	{
	480	struct lttng_event_rule_kernel_kprobe *kprobe;
	481	enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK;
	482
	483	if (!rule \|\| !IS_KPROBE_EVENT_RULE(rule) \|\| !name) {
	484	status = LTTNG_EVENT_RULE_STATUS_INVALID;
	485	goto end;
	486	}
	487
	488	kprobe = container_of(rule, struct lttng_event_rule_kernel_kprobe, parent);
	489	if (!kprobe->name) {
	490	status = LTTNG_EVENT_RULE_STATUS_UNSET;
	491	goto end;
	492	}
	493
	494	*name = kprobe->name;
	495	end:
	496	return status;
	497	}