[lttng-modules.git] / src / lttng-context-pid-ns.c

/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
 *
 * lttng-context-pid-ns.c
 *
 * LTTng pid 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/pid_namespace.h>
#include <lttng/events.h>
#include <lttng/events-internal.h>
#include <ringbuffer/frontend_types.h>
#include <wrapper/vmalloc.h>
#include <wrapper/namespace.h>
#include <lttng/tracer.h>

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

static
size_t pid_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 pid_ns_record(void *priv, struct lttng_kernel_probe_ctx *probe_ctx,
		 struct lttng_kernel_ring_buffer_ctx *ctx,
		 struct lttng_kernel_channel_buffer *chan)
{
	struct pid_namespace *ns;
	unsigned int pid_ns_inum = 0;

	/*
	 * The pid namespace is an exception -- it's accessed using
	 * task_active_pid_ns. The pid namespace in nsproxy is the
	 * namespace that children will use.
	 */
	ns = task_active_pid_ns(current);

	if (ns)
		pid_ns_inum = ns->lttng_ns_inum;

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

static
void pid_ns_get_value(void *priv,
		struct lttng_kernel_probe_ctx *lttng_probe_ctx,
		struct lttng_ctx_value *value)
{
	struct pid_namespace *ns;
	unsigned int pid_ns_inum = 0;

	/*
	 * The pid namespace is an exception -- it's accessed using
	 * task_active_pid_ns. The pid namespace in nsproxy is the
	 * namespace that children will use.
	 */
	ns = task_active_pid_ns(current);

	if (ns)
		pid_ns_inum = ns->lttng_ns_inum;

	value->u.s64 = pid_ns_inum;
}

static const struct lttng_kernel_ctx_field *ctx_field = lttng_kernel_static_ctx_field(
	lttng_kernel_static_event_field("pid_ns",
		lttng_kernel_static_type_integer_from_type(unsigned int, __BYTE_ORDER, 10),
		false, false, false),
	pid_ns_get_size,
	pid_ns_record,
	pid_ns_get_value,
	NULL, NULL);

int lttng_add_pid_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_pid_ns_to_ctx);

#endif
Commit	Line	Data
	1	/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
	2	*
	3	* lttng-context-pid-ns.c
	4	*
	5	* LTTng pid 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/pid_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 <wrapper/namespace.h>
	21	#include <lttng/tracer.h>
	22
	23	#if defined(CONFIG_PID_NS) && \
	24	(LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,8,0))
	25
	26	static
	27	size_t pid_ns_get_size(void priv, struct lttng_kernel_probe_ctx probe_ctx, size_t offset)
	28	{
	29	size_t size = 0;
	30
	31	size += lib_ring_buffer_align(offset, lttng_alignof(unsigned int));
	32	size += sizeof(unsigned int);
	33	return size;
	34	}
	35
	36	static
	37	void pid_ns_record(void priv, struct lttng_kernel_probe_ctx probe_ctx,
	38	struct lttng_kernel_ring_buffer_ctx *ctx,
	39	struct lttng_kernel_channel_buffer *chan)
	40	{
	41	struct pid_namespace *ns;
	42	unsigned int pid_ns_inum = 0;
	43
	44	/*
	45	* The pid namespace is an exception -- it's accessed using
	46	* task_active_pid_ns. The pid namespace in nsproxy is the
	47	* namespace that children will use.
	48	*/
	49	ns = task_active_pid_ns(current);
	50
	51	if (ns)
	52	pid_ns_inum = ns->lttng_ns_inum;
	53
	54	chan->ops->event_write(ctx, &pid_ns_inum, sizeof(pid_ns_inum), lttng_alignof(pid_ns_inum));
	55	}
	56
	57	static
	58	void pid_ns_get_value(void *priv,
	59	struct lttng_kernel_probe_ctx *lttng_probe_ctx,
	60	struct lttng_ctx_value *value)
	61	{
	62	struct pid_namespace *ns;
	63	unsigned int pid_ns_inum = 0;
	64
	65	/*
	66	* The pid namespace is an exception -- it's accessed using
	67	* task_active_pid_ns. The pid namespace in nsproxy is the
	68	* namespace that children will use.
	69	*/
	70	ns = task_active_pid_ns(current);
	71
	72	if (ns)
	73	pid_ns_inum = ns->lttng_ns_inum;
	74
	75	value->u.s64 = pid_ns_inum;
	76	}
	77
	78	static const struct lttng_kernel_ctx_field *ctx_field = lttng_kernel_static_ctx_field(
	79	lttng_kernel_static_event_field("pid_ns",
	80	lttng_kernel_static_type_integer_from_type(unsigned int, __BYTE_ORDER, 10),
	81	false, false, false),
	82	pid_ns_get_size,
	83	pid_ns_record,
	84	pid_ns_get_value,
	85	NULL, NULL);
	86
	87	int lttng_add_pid_ns_to_ctx(struct lttng_kernel_ctx **ctx)
	88	{
	89	int ret;
	90
	91	if (lttng_kernel_find_context(*ctx, ctx_field->event_field->name))
	92	return -EEXIST;
	93	ret = lttng_kernel_context_append(ctx, ctx_field);
	94	wrapper_vmalloc_sync_mappings();
	95	return ret;
	96	}
	97	EXPORT_SYMBOL_GPL(lttng_add_pid_ns_to_ctx);
	98
	99	#endif