[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>
 *
 */

#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>

#if defined(CONFIG_USER_NS) && \
	(LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,8,0))

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	#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 <lttng/events-internal.h>
	18	#include <ringbuffer/frontend_types.h>
	19	#include <wrapper/vmalloc.h>
	20	#include <lttng/tracer.h>
	21
	22	#if defined(CONFIG_USER_NS) && \
	23	(LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,8,0))
	24
	25	static
	26	size_t user_ns_get_size(void priv, struct lttng_kernel_probe_ctx probe_ctx, size_t offset)
	27	{
	28	size_t size = 0;
	29
	30	size += lib_ring_buffer_align(offset, lttng_alignof(unsigned int));
	31	size += sizeof(unsigned int);
	32	return size;
	33	}
	34
	35	static
	36	void user_ns_record(void priv, struct lttng_kernel_probe_ctx probe_ctx,
	37	struct lttng_kernel_ring_buffer_ctx *ctx,
	38	struct lttng_kernel_channel_buffer *chan)
	39	{
	40	unsigned int user_ns_inum = 0;
	41
	42	if (current_user_ns())
	43	user_ns_inum = current_user_ns()->ns.inum;
	44
	45	chan->ops->event_write(ctx, &user_ns_inum, sizeof(user_ns_inum), lttng_alignof(user_ns_inum));
	46	}
	47
	48	static
	49	void user_ns_get_value(void *priv,
	50	struct lttng_kernel_probe_ctx *lttng_probe_ctx,
	51	struct 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()->ns.inum;
	57
	58	value->u.s64 = user_ns_inum;
	59	}
	60
	61	static const struct lttng_kernel_ctx_field *ctx_field = lttng_kernel_static_ctx_field(
	62	lttng_kernel_static_event_field("user_ns",
	63	lttng_kernel_static_type_integer_from_type(unsigned int, __BYTE_ORDER, 10),
	64	false, false),
	65	user_ns_get_size,
	66	user_ns_record,
	67	user_ns_get_value,
	68	NULL, NULL);
	69
	70	int lttng_add_user_ns_to_ctx(struct lttng_kernel_ctx **ctx)
	71	{
	72	int ret;
	73
	74	if (lttng_kernel_find_context(*ctx, ctx_field->event_field->name))
	75	return -EEXIST;
	76	ret = lttng_kernel_context_append(ctx, ctx_field);
	77	wrapper_vmalloc_sync_mappings();
	78	return ret;
	79	}
	80	EXPORT_SYMBOL_GPL(lttng_add_user_ns_to_ctx);
	81
	82	#endif