[lttng-modules.git] / lttng-context-user-ns.c

/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
 *
 * lttng-context-user-ns.c
 *
 * LTTng user namespace context.
 *
 * Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *               2019 Michael Jeanson <mjeanson@efficios.com>
 *
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/user_namespace.h>
#include <lttng-events.h>
#include <wrapper/ringbuffer/frontend_types.h>
#include <wrapper/namespace.h>
#include <lttng-tracer.h>

#if defined(CONFIG_USER_NS) && \
	(LINUX_VERSION_CODE >= KERNEL_VERSION(3,8,0))

static
size_t user_ns_get_size(size_t offset)
{
	size_t size = 0;

	size += lib_ring_buffer_align(offset, lttng_alignof(unsigned int));
	size += sizeof(unsigned int);
	return size;
}

static
void user_ns_record(struct lttng_ctx_field *field,
		 struct lib_ring_buffer_ctx *ctx,
		 struct lttng_channel *chan)
{
	unsigned int user_ns_inum = 0;

	if (current_user_ns())
		user_ns_inum = current_user_ns()->lttng_ns_inum;

	lib_ring_buffer_align_ctx(ctx, lttng_alignof(user_ns_inum));
	chan->ops->event_write(ctx, &user_ns_inum, sizeof(user_ns_inum));
}

static
void user_ns_get_value(struct lttng_ctx_field *field,
		struct lttng_probe_ctx *lttng_probe_ctx,
		union lttng_ctx_value *value)
{
	unsigned int user_ns_inum = 0;

	if (current_user_ns())
		user_ns_inum = current_user_ns()->lttng_ns_inum;

	value->s64 = user_ns_inum;
}

int lttng_add_user_ns_to_ctx(struct lttng_ctx **ctx)
{
	struct lttng_ctx_field *field;

	field = lttng_append_context(ctx);
	if (!field)
		return -ENOMEM;
	if (lttng_find_context(*ctx, "user_ns")) {
		lttng_remove_context_field(ctx, field);
		return -EEXIST;
	}
	field->event_field.name = "user_ns";
	field->event_field.type.atype = atype_integer;
	field->event_field.type.u.integer.size = sizeof(unsigned int) * CHAR_BIT;
	field->event_field.type.u.integer.alignment = lttng_alignof(unsigned int) * CHAR_BIT;
	field->event_field.type.u.integer.signedness = lttng_is_signed_type(unsigned int);
	field->event_field.type.u.integer.reverse_byte_order = 0;
	field->event_field.type.u.integer.base = 10;
	field->event_field.type.u.integer.encoding = lttng_encode_none;
	field->get_size = user_ns_get_size;
	field->record = user_ns_record;
	field->get_value = user_ns_get_value;
	lttng_context_update(*ctx);
	return 0;
}
EXPORT_SYMBOL_GPL(lttng_add_user_ns_to_ctx);

#endif
Commit	Line	Data
b7cdc182	1	/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
a6cf40a4 MJ	2	*
	3	* lttng-context-user-ns.c
	4	*
	5	* LTTng user namespace context.
	6	*
	7	* Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	8	* 2019 Michael Jeanson <mjeanson@efficios.com>
	9	*
	10	*/
	11
	12	#include <linux/module.h>
	13	#include <linux/slab.h>
	14	#include <linux/sched.h>
	15	#include <linux/user_namespace.h>
	16	#include <lttng-events.h>
	17	#include <wrapper/ringbuffer/frontend_types.h>
a6cf40a4 MJ	18	#include <wrapper/namespace.h>
	19	#include <lttng-tracer.h>
	20
	21	#if defined(CONFIG_USER_NS) && \
	22	(LINUX_VERSION_CODE >= KERNEL_VERSION(3,8,0))
	23
	24	static
	25	size_t user_ns_get_size(size_t offset)
	26	{
	27	size_t size = 0;
	28
	29	size += lib_ring_buffer_align(offset, lttng_alignof(unsigned int));
	30	size += sizeof(unsigned int);
	31	return size;
	32	}
	33
	34	static
	35	void user_ns_record(struct lttng_ctx_field *field,
	36	struct lib_ring_buffer_ctx *ctx,
	37	struct lttng_channel *chan)
	38	{
	39	unsigned int user_ns_inum = 0;
	40
	41	if (current_user_ns())
	42	user_ns_inum = current_user_ns()->lttng_ns_inum;
	43
	44	lib_ring_buffer_align_ctx(ctx, lttng_alignof(user_ns_inum));
	45	chan->ops->event_write(ctx, &user_ns_inum, sizeof(user_ns_inum));
	46	}
	47
	48	static
	49	void user_ns_get_value(struct lttng_ctx_field *field,
	50	struct lttng_probe_ctx *lttng_probe_ctx,
	51	union lttng_ctx_value *value)
	52	{
	53	unsigned int user_ns_inum = 0;
	54
	55	if (current_user_ns())
	56	user_ns_inum = current_user_ns()->lttng_ns_inum;
	57
	58	value->s64 = user_ns_inum;
	59	}
	60
	61	int lttng_add_user_ns_to_ctx(struct lttng_ctx **ctx)
	62	{
	63	struct lttng_ctx_field *field;
	64
	65	field = lttng_append_context(ctx);
	66	if (!field)
	67	return -ENOMEM;
	68	if (lttng_find_context(*ctx, "user_ns")) {
	69	lttng_remove_context_field(ctx, field);
	70	return -EEXIST;
	71	}
	72	field->event_field.name = "user_ns";
	73	field->event_field.type.atype = atype_integer;
ceabb767 MD	74	field->event_field.type.u.integer.size = sizeof(unsigned int) * CHAR_BIT;
	75	field->event_field.type.u.integer.alignment = lttng_alignof(unsigned int) * CHAR_BIT;
	76	field->event_field.type.u.integer.signedness = lttng_is_signed_type(unsigned int);
	77	field->event_field.type.u.integer.reverse_byte_order = 0;
	78	field->event_field.type.u.integer.base = 10;
	79	field->event_field.type.u.integer.encoding = lttng_encode_none;
a6cf40a4 MJ	80	field->get_size = user_ns_get_size;
	81	field->record = user_ns_record;
	82	field->get_value = user_ns_get_value;
	83	lttng_context_update(*ctx);
a6cf40a4 MJ	84	return 0;
	85	}
	86	EXPORT_SYMBOL_GPL(lttng_add_user_ns_to_ctx);
	87
	88	#endif