[lttng-modules.git] / src / probes / lttng-kretprobes.c

/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
 *
 * probes/lttng-kretprobes.c
 *
 * LTTng kretprobes integration module.
 *
 * Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 */

#include <linux/module.h>
#include <wrapper/kprobes.h>
#include <linux/slab.h>
#include <linux/kref.h>
#include <lttng/events.h>
#include <lttng/events-internal.h>
#include <ringbuffer/frontend_types.h>
#include <wrapper/vmalloc.h>
#include <wrapper/irqflags.h>
#include <lttng/tracer.h>
#include <blacklist/kprobes.h>

enum lttng_kretprobe_type {
	EVENT_ENTRY	= 0,
	EVENT_EXIT	= 1,
};

struct lttng_krp {
	struct kretprobe krp;
	struct lttng_kernel_event_common *event[2];	/* ENTRY and EXIT */
	struct kref kref_register;
	struct kref kref_alloc;
};

static
int _lttng_kretprobes_handler(struct kretprobe_instance *krpi,
			      struct pt_regs *regs,
			      enum lttng_kretprobe_type type)
{
	struct lttng_krp *lttng_krp =
		container_of(lttng_get_kretprobe(krpi), struct lttng_krp, krp);
	struct lttng_kernel_event_common *event = lttng_krp->event[type];
	struct lttng_kernel_probe_ctx lttng_probe_ctx = {
		.event = event,
		.interruptible = !lttng_regs_irqs_disabled(regs),
	};
	struct {
		unsigned long ip;
		unsigned long parent_ip;
	} payload;

	switch (event->type) {
	case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
	{
		struct lttng_kernel_event_recorder *event_recorder =
			container_of(event, struct lttng_kernel_event_recorder, parent);
		struct lttng_channel *chan = event_recorder->chan;

		if (unlikely(!LTTNG_READ_ONCE(chan->session->active)))
			return 0;
		if (unlikely(!LTTNG_READ_ONCE(chan->enabled)))
			return 0;
		break;
	}
	case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:	/* Fall-through. */
	default:
		WARN_ON_ONCE(1);
	}

	if (unlikely(!LTTNG_READ_ONCE(event->enabled)))
		return 0;

	switch (event->type) {
	case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
	{
		struct lttng_kernel_event_recorder *event_recorder =
			container_of(event, struct lttng_kernel_event_recorder, parent);
		struct lttng_channel *chan = event_recorder->chan;
		struct lttng_kernel_ring_buffer_ctx ctx;
		int ret;

		payload.ip = (unsigned long) lttng_get_kretprobe(krpi)->kp.addr;
		payload.parent_ip = (unsigned long) krpi->ret_addr;

		lib_ring_buffer_ctx_init(&ctx, event_recorder, sizeof(payload),
					 lttng_alignof(payload), &lttng_probe_ctx);
		ret = chan->ops->event_reserve(&ctx);
		if (ret < 0)
			return 0;
		lib_ring_buffer_align_ctx(&ctx, lttng_alignof(payload));
		chan->ops->event_write(&ctx, &payload, sizeof(payload));
		chan->ops->event_commit(&ctx);
		break;
	}
	case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:	/* Fall-through. */
	default:
		WARN_ON_ONCE(1);
	}
	return 0;
}

static
int lttng_kretprobes_handler_entry(struct kretprobe_instance *krpi,
				   struct pt_regs *regs)
{
	return _lttng_kretprobes_handler(krpi, regs, EVENT_ENTRY);
}

static
int lttng_kretprobes_handler_exit(struct kretprobe_instance *krpi,
				  struct pt_regs *regs)
{
	return _lttng_kretprobes_handler(krpi, regs, EVENT_EXIT);
}

static const struct lttng_kernel_event_field *event_fields[] = {
	lttng_kernel_static_event_field("ip",
		lttng_kernel_static_type_integer_from_type(unsigned long, __BYTE_ORDER, 16),
		false, false, false),
	lttng_kernel_static_event_field("parent_ip",
		lttng_kernel_static_type_integer_from_type(unsigned long, __BYTE_ORDER, 16),
		false, false, false),
};

static const struct lttng_kernel_tracepoint_class tp_class = {
	.nr_fields = ARRAY_SIZE(event_fields),
	.fields = event_fields,
};

/*
 * Create event description
 */
static
int lttng_create_kprobe_event(const char *name, struct lttng_kernel_event_recorder *event_recorder,
			      enum lttng_kretprobe_type type)
{
	struct lttng_kernel_event_desc *desc;
	char *alloc_name;
	size_t name_len;
	const char *suffix = NULL;
	int ret;

	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
	if (!desc)
		return -ENOMEM;
	name_len = strlen(name);
	switch (type) {
	case EVENT_ENTRY:
		suffix = "_entry";
		break;
	case EVENT_EXIT:
		suffix = "_exit";
		break;
	}
	name_len += strlen(suffix);
	alloc_name = kmalloc(name_len + 1, GFP_KERNEL);
	if (!alloc_name) {
		ret = -ENOMEM;
		goto error_str;
	}
	strcpy(alloc_name, name);
	strcat(alloc_name, suffix);
	desc->event_name = alloc_name;
	desc->tp_class = &tp_class;
	desc->owner = THIS_MODULE;
	event_recorder->priv->parent.desc = desc;

	return 0;

error_str:
	kfree(desc);
	return ret;
}

int lttng_kretprobes_register(const char *name,
			   const char *symbol_name,
			   uint64_t offset,
			   uint64_t addr,
			   struct lttng_kernel_event_recorder *event_recorder_entry,
			   struct lttng_kernel_event_recorder *event_recorder_exit)
{
	int ret;
	struct lttng_krp *lttng_krp;

	/* Kprobes expects a NULL symbol name if unused */
	if (symbol_name[0] == '\0')
		symbol_name = NULL;

	ret = lttng_create_kprobe_event(name, event_recorder_entry, EVENT_ENTRY);
	if (ret)
		goto error;
	ret = lttng_create_kprobe_event(name, event_recorder_exit, EVENT_EXIT);
	if (ret)
		goto event_exit_error;
	lttng_krp = kzalloc(sizeof(*lttng_krp), GFP_KERNEL);
	if (!lttng_krp)
		goto krp_error;
	lttng_krp->krp.entry_handler = lttng_kretprobes_handler_entry;
	lttng_krp->krp.handler = lttng_kretprobes_handler_exit;
	if (symbol_name) {
		char *alloc_symbol;

		alloc_symbol = kstrdup(symbol_name, GFP_KERNEL);
		if (!alloc_symbol) {
			ret = -ENOMEM;
			goto name_error;
		}
		lttng_krp->krp.kp.symbol_name =
			alloc_symbol;
		event_recorder_entry->priv->parent.u.kretprobe.symbol_name =
			alloc_symbol;
		event_recorder_exit->priv->parent.u.kretprobe.symbol_name =
			alloc_symbol;
	}
	lttng_krp->krp.kp.offset = offset;
	lttng_krp->krp.kp.addr = (void *) (unsigned long) addr;

	/* Allow probe handler to find event structures */
	lttng_krp->event[EVENT_ENTRY] = &event_recorder_entry->parent;
	lttng_krp->event[EVENT_EXIT] = &event_recorder_exit->parent;
	event_recorder_entry->priv->parent.u.kretprobe.lttng_krp = lttng_krp;
	event_recorder_exit->priv->parent.u.kretprobe.lttng_krp = lttng_krp;

	/*
	 * Both events must be unregistered before the kretprobe is
	 * unregistered. Same for memory allocation.
	 */
	kref_init(&lttng_krp->kref_alloc);
	kref_get(&lttng_krp->kref_alloc);	/* inc refcount to 2, no overflow. */
	kref_init(&lttng_krp->kref_register);
	kref_get(&lttng_krp->kref_register);	/* inc refcount to 2, no overflow. */

	/*
	 * Ensure the memory we just allocated don't trigger page faults.
	 * Well.. kprobes itself puts the page fault handler on the blacklist,
	 * but we can never be too careful.
	 */
	wrapper_vmalloc_sync_mappings();

	ret = register_kretprobe(&lttng_krp->krp);
	if (ret)
		goto register_error;
	return 0;

register_error:
	kfree(lttng_krp->krp.kp.symbol_name);
name_error:
	kfree(lttng_krp);
krp_error:
	kfree(event_recorder_exit->priv->parent.desc->event_name);
	kfree(event_recorder_exit->priv->parent.desc);
event_exit_error:
	kfree(event_recorder_entry->priv->parent.desc->event_name);
	kfree(event_recorder_entry->priv->parent.desc);
error:
	return ret;
}
EXPORT_SYMBOL_GPL(lttng_kretprobes_register);

static
void _lttng_kretprobes_unregister_release(struct kref *kref)
{
	struct lttng_krp *lttng_krp =
		container_of(kref, struct lttng_krp, kref_register);
	unregister_kretprobe(&lttng_krp->krp);
}

void lttng_kretprobes_unregister(struct lttng_kernel_event_recorder *event_recorder)
{
	kref_put(&event_recorder->priv->parent.u.kretprobe.lttng_krp->kref_register,
		_lttng_kretprobes_unregister_release);
}
EXPORT_SYMBOL_GPL(lttng_kretprobes_unregister);

static
void _lttng_kretprobes_release(struct kref *kref)
{
	struct lttng_krp *lttng_krp =
		container_of(kref, struct lttng_krp, kref_alloc);
	kfree(lttng_krp->krp.kp.symbol_name);
}

void lttng_kretprobes_destroy_private(struct lttng_kernel_event_recorder *event_recorder)
{
	kfree(event_recorder->priv->parent.desc->event_name);
	kfree(event_recorder->priv->parent.desc);
	kref_put(&event_recorder->priv->parent.u.kretprobe.lttng_krp->kref_alloc,
		_lttng_kretprobes_release);
}
EXPORT_SYMBOL_GPL(lttng_kretprobes_destroy_private);

int lttng_kretprobes_event_enable_state(struct lttng_kernel_event_common *event,
		int enable)
{
	struct lttng_kernel_event_common *event_exit;
	struct lttng_krp *lttng_krp;

	if (event->priv->instrumentation != LTTNG_KERNEL_ABI_KRETPROBE) {
		return -EINVAL;
	}
	if (event->enabled == enable) {
		return -EBUSY;
	}
	lttng_krp = event->priv->u.kretprobe.lttng_krp;
	event_exit = lttng_krp->event[EVENT_EXIT];
	WRITE_ONCE(event->enabled, enable);
	WRITE_ONCE(event_exit->enabled, enable);
	return 0;
}
EXPORT_SYMBOL_GPL(lttng_kretprobes_event_enable_state);

MODULE_LICENSE("GPL and additional rights");
MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
MODULE_DESCRIPTION("LTTng kretprobes probes");
MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
	__stringify(LTTNG_MODULES_MINOR_VERSION) "."
	__stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
	LTTNG_MODULES_EXTRAVERSION);
Commit	Line	Data
b7cdc182	1	/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
9f36eaed MJ	2	*
9f36eaed MJ	3	* probes/lttng-kretprobes.c
7371f44c MD	4	*
	5	* LTTng kretprobes integration module.
	6	*
886d51a3	7	* Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
7371f44c MD	8	*/
	9
	10	#include <linux/module.h>
08726907	11	#include <wrapper/kprobes.h>
7371f44c MD	12	#include <linux/slab.h>
7371f44c MD	13	#include <linux/kref.h>
2df37e95	14	#include <lttng/events.h>
a67ba386	15	#include <lttng/events-internal.h>
24591303	16	#include <ringbuffer/frontend_types.h>
156a3977 MD	17	#include <wrapper/vmalloc.h>
156a3977 MD	18	#include <wrapper/irqflags.h>
2df37e95	19	#include <lttng/tracer.h>
caa068b5	20	#include <blacklist/kprobes.h>
7371f44c MD	21
7371f44c MD	22	enum lttng_kretprobe_type {
1b6cc48a MD	23	EVENT_ENTRY = 0,
1b6cc48a MD	24	EVENT_EXIT = 1,
7371f44c MD	25	};
	26
	27	struct lttng_krp {
	28	struct kretprobe krp;
e2d5dbc7	29	struct lttng_kernel_event_common event[2]; / ENTRY and EXIT */
7371f44c MD	30	struct kref kref_register;
	31	struct kref kref_alloc;
	32	};
	33
	34	static
	35	int _lttng_kretprobes_handler(struct kretprobe_instance *krpi,
	36	struct pt_regs *regs,
	37	enum lttng_kretprobe_type type)
	38	{
	39	struct lttng_krp *lttng_krp =
08726907	40	container_of(lttng_get_kretprobe(krpi), struct lttng_krp, krp);
e2d5dbc7	41	struct lttng_kernel_event_common *event = lttng_krp->event[type];
a92e844e	42	struct lttng_kernel_probe_ctx lttng_probe_ctx = {
e2d5dbc7	43	.event = event,
ccecf3fb	44	.interruptible = !lttng_regs_irqs_disabled(regs),
79150a49	45	};
7371f44c MD	46	struct {
	47	unsigned long ip;
	48	unsigned long parent_ip;
	49	} payload;
	50
e2d5dbc7 MD	51	switch (event->type) {
	52	case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
	53	{
	54	struct lttng_kernel_event_recorder *event_recorder =
	55	container_of(event, struct lttng_kernel_event_recorder, parent);
	56	struct lttng_channel *chan = event_recorder->chan;
	57
	58	if (unlikely(!LTTNG_READ_ONCE(chan->session->active)))
	59	return 0;
	60	if (unlikely(!LTTNG_READ_ONCE(chan->enabled)))
	61	return 0;
	62	break;
	63	}
	64	case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER: /* Fall-through. */
	65	default:
	66	WARN_ON_ONCE(1);
	67	}
7371f44c	68
e2d5dbc7	69	if (unlikely(!LTTNG_READ_ONCE(event->enabled)))
7371f44c	70	return 0;
e2d5dbc7 MD	71
	72	switch (event->type) {
	73	case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
	74	{
	75	struct lttng_kernel_event_recorder *event_recorder =
	76	container_of(event, struct lttng_kernel_event_recorder, parent);
	77	struct lttng_channel *chan = event_recorder->chan;
8a57ec02	78	struct lttng_kernel_ring_buffer_ctx ctx;
e2d5dbc7 MD	79	int ret;
	80
	81	payload.ip = (unsigned long) lttng_get_kretprobe(krpi)->kp.addr;
	82	payload.parent_ip = (unsigned long) krpi->ret_addr;
	83
b1199bd3 MD	84	lib_ring_buffer_ctx_init(&ctx, event_recorder, sizeof(payload),
b1199bd3 MD	85	lttng_alignof(payload), &lttng_probe_ctx);
c2fb9c1c	86	ret = chan->ops->event_reserve(&ctx);
e2d5dbc7 MD	87	if (ret < 0)
	88	return 0;
	89	lib_ring_buffer_align_ctx(&ctx, lttng_alignof(payload));
	90	chan->ops->event_write(&ctx, &payload, sizeof(payload));
	91	chan->ops->event_commit(&ctx);
	92	break;
	93	}
	94	case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER: /* Fall-through. */
	95	default:
	96	WARN_ON_ONCE(1);
	97	}
7371f44c MD	98	return 0;
	99	}
	100
	101	static
	102	int lttng_kretprobes_handler_entry(struct kretprobe_instance *krpi,
	103	struct pt_regs *regs)
	104	{
	105	return _lttng_kretprobes_handler(krpi, regs, EVENT_ENTRY);
	106	}
	107
	108	static
1b6cc48a MD	109	int lttng_kretprobes_handler_exit(struct kretprobe_instance *krpi,
1b6cc48a MD	110	struct pt_regs *regs)
7371f44c	111	{
1b6cc48a	112	return _lttng_kretprobes_handler(krpi, regs, EVENT_EXIT);
7371f44c MD	113	}
7371f44c MD	114
6c8c025b MD	115	static const struct lttng_kernel_event_field *event_fields[] = {
	116	lttng_kernel_static_event_field("ip",
	117	lttng_kernel_static_type_integer_from_type(unsigned long, __BYTE_ORDER, 16),
	118	false, false, false),
	119	lttng_kernel_static_event_field("parent_ip",
	120	lttng_kernel_static_type_integer_from_type(unsigned long, __BYTE_ORDER, 16),
	121	false, false, false),
	122	};
	123
	124	static const struct lttng_kernel_tracepoint_class tp_class = {
	125	.nr_fields = ARRAY_SIZE(event_fields),
	126	.fields = event_fields,
	127	};
437d5aa5	128
7371f44c MD	129	/*
	130	* Create event description
	131	*/
	132	static
a67ba386	133	int lttng_create_kprobe_event(const char name, struct lttng_kernel_event_recorder event_recorder,
7371f44c MD	134	enum lttng_kretprobe_type type)
7371f44c MD	135	{
437d5aa5	136	struct lttng_kernel_event_desc *desc;
7371f44c MD	137	char *alloc_name;
	138	size_t name_len;
	139	const char *suffix = NULL;
437d5aa5	140	int ret;
7371f44c	141
437d5aa5	142	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
7371f44c MD	143	if (!desc)
	144	return -ENOMEM;
	145	name_len = strlen(name);
	146	switch (type) {
	147	case EVENT_ENTRY:
	148	suffix = "_entry";
	149	break;
1b6cc48a MD	150	case EVENT_EXIT:
1b6cc48a MD	151	suffix = "_exit";
7371f44c MD	152	break;
	153	}
	154	name_len += strlen(suffix);
	155	alloc_name = kmalloc(name_len + 1, GFP_KERNEL);
	156	if (!alloc_name) {
	157	ret = -ENOMEM;
	158	goto error_str;
	159	}
	160	strcpy(alloc_name, name);
	161	strcat(alloc_name, suffix);
437d5aa5	162	desc->event_name = alloc_name;
6c8c025b	163	desc->tp_class = &tp_class;
7371f44c	164	desc->owner = THIS_MODULE;
a67ba386	165	event_recorder->priv->parent.desc = desc;
7371f44c MD	166
	167	return 0;
	168
7371f44c MD	169	error_str:
	170	kfree(desc);
	171	return ret;
	172	}
	173
	174	int lttng_kretprobes_register(const char *name,
	175	const char *symbol_name,
	176	uint64_t offset,
	177	uint64_t addr,
a67ba386 MD	178	struct lttng_kernel_event_recorder *event_recorder_entry,
a67ba386 MD	179	struct lttng_kernel_event_recorder *event_recorder_exit)
7371f44c MD	180	{
	181	int ret;
	182	struct lttng_krp *lttng_krp;
	183
	184	/* Kprobes expects a NULL symbol name if unused */
	185	if (symbol_name[0] == '\0')
	186	symbol_name = NULL;
	187
a67ba386	188	ret = lttng_create_kprobe_event(name, event_recorder_entry, EVENT_ENTRY);
7371f44c MD	189	if (ret)
7371f44c MD	190	goto error;
a67ba386	191	ret = lttng_create_kprobe_event(name, event_recorder_exit, EVENT_EXIT);
7371f44c	192	if (ret)
1b6cc48a	193	goto event_exit_error;
7371f44c MD	194	lttng_krp = kzalloc(sizeof(*lttng_krp), GFP_KERNEL);
	195	if (!lttng_krp)
	196	goto krp_error;
	197	lttng_krp->krp.entry_handler = lttng_kretprobes_handler_entry;
1b6cc48a	198	lttng_krp->krp.handler = lttng_kretprobes_handler_exit;
7371f44c MD	199	if (symbol_name) {
	200	char *alloc_symbol;
	201
	202	alloc_symbol = kstrdup(symbol_name, GFP_KERNEL);
	203	if (!alloc_symbol) {
	204	ret = -ENOMEM;
	205	goto name_error;
	206	}
	207	lttng_krp->krp.kp.symbol_name =
	208	alloc_symbol;
a67ba386	209	event_recorder_entry->priv->parent.u.kretprobe.symbol_name =
7371f44c	210	alloc_symbol;
a67ba386	211	event_recorder_exit->priv->parent.u.kretprobe.symbol_name =
7371f44c MD	212	alloc_symbol;
	213	}
	214	lttng_krp->krp.kp.offset = offset;
b2c4e8fb	215	lttng_krp->krp.kp.addr = (void *) (unsigned long) addr;
7371f44c MD	216
7371f44c MD	217	/* Allow probe handler to find event structures */
e2d5dbc7 MD	218	lttng_krp->event[EVENT_ENTRY] = &event_recorder_entry->parent;
e2d5dbc7 MD	219	lttng_krp->event[EVENT_EXIT] = &event_recorder_exit->parent;
a67ba386 MD	220	event_recorder_entry->priv->parent.u.kretprobe.lttng_krp = lttng_krp;
a67ba386 MD	221	event_recorder_exit->priv->parent.u.kretprobe.lttng_krp = lttng_krp;
7371f44c MD	222
	223	/*
	224	* Both events must be unregistered before the kretprobe is
	225	* unregistered. Same for memory allocation.
	226	*/
	227	kref_init(&lttng_krp->kref_alloc);
9c1f4643	228	kref_get(&lttng_krp->kref_alloc); /* inc refcount to 2, no overflow. */
7371f44c	229	kref_init(&lttng_krp->kref_register);
9c1f4643	230	kref_get(&lttng_krp->kref_register); /* inc refcount to 2, no overflow. */
7371f44c MD	231
	232	/*
	233	* Ensure the memory we just allocated don't trigger page faults.
	234	* Well.. kprobes itself puts the page fault handler on the blacklist,
	235	* but we can never be too careful.
	236	*/
263b6c88	237	wrapper_vmalloc_sync_mappings();
7371f44c MD	238
	239	ret = register_kretprobe(&lttng_krp->krp);
	240	if (ret)
	241	goto register_error;
	242	return 0;
	243
	244	register_error:
	245	kfree(lttng_krp->krp.kp.symbol_name);
	246	name_error:
	247	kfree(lttng_krp);
	248	krp_error:
a67ba386 MD	249	kfree(event_recorder_exit->priv->parent.desc->event_name);
a67ba386 MD	250	kfree(event_recorder_exit->priv->parent.desc);
1b6cc48a	251	event_exit_error:
a67ba386 MD	252	kfree(event_recorder_entry->priv->parent.desc->event_name);
a67ba386 MD	253	kfree(event_recorder_entry->priv->parent.desc);
7371f44c MD	254	error:
	255	return ret;
	256	}
	257	EXPORT_SYMBOL_GPL(lttng_kretprobes_register);
	258
	259	static
	260	void _lttng_kretprobes_unregister_release(struct kref *kref)
	261	{
	262	struct lttng_krp *lttng_krp =
	263	container_of(kref, struct lttng_krp, kref_register);
	264	unregister_kretprobe(&lttng_krp->krp);
	265	}
	266
a67ba386	267	void lttng_kretprobes_unregister(struct lttng_kernel_event_recorder *event_recorder)
7371f44c	268	{
a67ba386	269	kref_put(&event_recorder->priv->parent.u.kretprobe.lttng_krp->kref_register,
7371f44c MD	270	_lttng_kretprobes_unregister_release);
	271	}
	272	EXPORT_SYMBOL_GPL(lttng_kretprobes_unregister);
	273
	274	static
	275	void _lttng_kretprobes_release(struct kref *kref)
	276	{
	277	struct lttng_krp *lttng_krp =
	278	container_of(kref, struct lttng_krp, kref_alloc);
	279	kfree(lttng_krp->krp.kp.symbol_name);
	280	}
	281
a67ba386	282	void lttng_kretprobes_destroy_private(struct lttng_kernel_event_recorder *event_recorder)
7371f44c	283	{
a67ba386 MD	284	kfree(event_recorder->priv->parent.desc->event_name);
	285	kfree(event_recorder->priv->parent.desc);
	286	kref_put(&event_recorder->priv->parent.u.kretprobe.lttng_krp->kref_alloc,
7371f44c MD	287	_lttng_kretprobes_release);
	288	}
	289	EXPORT_SYMBOL_GPL(lttng_kretprobes_destroy_private);
	290
e2d5dbc7	291	int lttng_kretprobes_event_enable_state(struct lttng_kernel_event_common *event,
a0493bef MD	292	int enable)
a0493bef MD	293	{
e2d5dbc7	294	struct lttng_kernel_event_common *event_exit;
a0493bef MD	295	struct lttng_krp *lttng_krp;
a0493bef MD	296
e2d5dbc7	297	if (event->priv->instrumentation != LTTNG_KERNEL_ABI_KRETPROBE) {
a0493bef MD	298	return -EINVAL;
a0493bef MD	299	}
e2d5dbc7	300	if (event->enabled == enable) {
a0493bef MD	301	return -EBUSY;
a0493bef MD	302	}
e2d5dbc7 MD	303	lttng_krp = event->priv->u.kretprobe.lttng_krp;
	304	event_exit = lttng_krp->event[EVENT_EXIT];
	305	WRITE_ONCE(event->enabled, enable);
	306	WRITE_ONCE(event_exit->enabled, enable);
a0493bef MD	307	return 0;
	308	}
	309	EXPORT_SYMBOL_GPL(lttng_kretprobes_event_enable_state);
	310
7371f44c	311	MODULE_LICENSE("GPL and additional rights");
1c124020 MJ	312	MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
1c124020 MJ	313	MODULE_DESCRIPTION("LTTng kretprobes probes");
13ab8b0a MD	314	MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
	315	__stringify(LTTNG_MODULES_MINOR_VERSION) "."
	316	__stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
	317	LTTNG_MODULES_EXTRAVERSION);