[lttng-modules.git] / src / 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>
 *
 */

#ifdef CONFIG_USER_NS

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

static
size_t user_ns_get_size(void *priv, struct lttng_kernel_probe_ctx *probe_ctx, 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(void *priv, struct lttng_kernel_probe_ctx *probe_ctx,
		 struct lttng_kernel_ring_buffer_ctx *ctx,
		 struct lttng_kernel_channel_buffer *chan)
{
	unsigned int user_ns_inum = 0;

	if (current_user_ns())
		user_ns_inum = current_user_ns()->ns.inum;

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

static
void user_ns_get_value(void *priv,
		struct lttng_kernel_probe_ctx *lttng_probe_ctx,
		struct lttng_ctx_value *value)
{
	unsigned int user_ns_inum = 0;

	if (current_user_ns())
		user_ns_inum = current_user_ns()->ns.inum;

	value->u.s64 = user_ns_inum;
}

static const struct lttng_kernel_ctx_field *ctx_field = lttng_kernel_static_ctx_field(
	lttng_kernel_static_event_field("user_ns",
		lttng_kernel_static_type_integer_from_type(unsigned int, __BYTE_ORDER, 10),
		false, false),
	user_ns_get_size,
	user_ns_record,
	user_ns_get_value,
	NULL, NULL);

int lttng_add_user_ns_to_ctx(struct lttng_kernel_ctx **ctx)
{
	int ret;

	if (lttng_kernel_find_context(*ctx, ctx_field->event_field->name))
		return -EEXIST;
	ret = lttng_kernel_context_append(ctx, ctx_field);
	wrapper_vmalloc_sync_mappings();
	return ret;
}
EXPORT_SYMBOL_GPL(lttng_add_user_ns_to_ctx);

#endif
Commit	Line	Data
	1	/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
	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	#ifdef CONFIG_USER_NS
	13
	14	#include <linux/module.h>
	15	#include <linux/slab.h>
	16	#include <linux/sched.h>
	17	#include <linux/user_namespace.h>
	18	#include <lttng/events.h>
	19	#include <lttng/events-internal.h>
	20	#include <ringbuffer/frontend_types.h>
	21	#include <wrapper/vmalloc.h>
	22	#include <lttng/tracer.h>
	23
	24	static
	25	size_t user_ns_get_size(void priv, struct lttng_kernel_probe_ctx probe_ctx, 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(void priv, struct lttng_kernel_probe_ctx probe_ctx,
	36	struct lttng_kernel_ring_buffer_ctx *ctx,
	37	struct lttng_kernel_channel_buffer *chan)
	38	{
	39	unsigned int user_ns_inum = 0;
	40
	41	if (current_user_ns())
	42	user_ns_inum = current_user_ns()->ns.inum;
	43
	44	chan->ops->event_write(ctx, &user_ns_inum, sizeof(user_ns_inum), lttng_alignof(user_ns_inum));
	45	}
	46
	47	static
	48	void user_ns_get_value(void *priv,
	49	struct lttng_kernel_probe_ctx *lttng_probe_ctx,
	50	struct lttng_ctx_value *value)
	51	{
	52	unsigned int user_ns_inum = 0;
	53
	54	if (current_user_ns())
	55	user_ns_inum = current_user_ns()->ns.inum;
	56
	57	value->u.s64 = user_ns_inum;
	58	}
	59
	60	static const struct lttng_kernel_ctx_field *ctx_field = lttng_kernel_static_ctx_field(
	61	lttng_kernel_static_event_field("user_ns",
	62	lttng_kernel_static_type_integer_from_type(unsigned int, __BYTE_ORDER, 10),
	63	false, false),
	64	user_ns_get_size,
	65	user_ns_record,
	66	user_ns_get_value,
	67	NULL, NULL);
	68
	69	int lttng_add_user_ns_to_ctx(struct lttng_kernel_ctx **ctx)
	70	{
	71	int ret;
	72
	73	if (lttng_kernel_find_context(*ctx, ctx_field->event_field->name))
	74	return -EEXIST;
	75	ret = lttng_kernel_context_append(ctx, ctx_field);
	76	wrapper_vmalloc_sync_mappings();
	77	return ret;
	78	}
	79	EXPORT_SYMBOL_GPL(lttng_add_user_ns_to_ctx);
	80
	81	#endif