[lttng-modules.git] / lttng-context-vpid.c

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

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

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

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

static
void vpid_record(struct lttng_ctx_field *field,
		 struct lib_ring_buffer_ctx *ctx,
		 struct lttng_channel *chan)
{
	pid_t vpid;

	/*
	 * nsproxy can be NULL when scheduled out of exit.
	 */
	if (!current->nsproxy)
		vpid = 0;
	else
		vpid = task_tgid_vnr(current);
	lib_ring_buffer_align_ctx(ctx, lttng_alignof(vpid));
	chan->ops->event_write(ctx, &vpid, sizeof(vpid));
}

static
void vpid_get_value(struct lttng_ctx_field *field,
		struct lttng_probe_ctx *lttng_probe_ctx,
		union lttng_ctx_value *value)
{
	pid_t vpid;

	/*
	 * nsproxy can be NULL when scheduled out of exit.
	 */
	if (!current->nsproxy)
		vpid = 0;
	else
		vpid = task_tgid_vnr(current);
	value->s64 = vpid;
}

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