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

/*
 * lttng-context-vtid.c
 *
 * LTTng vTID context.
 *
 * Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; only
 * version 2.1 of the License.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

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

static
size_t vtid_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 vtid_record(struct lttng_ctx_field *field,
		 struct lib_ring_buffer_ctx *ctx,
		 struct lttng_channel *chan)
{
	pid_t vtid;

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

int lttng_add_vtid_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, "vtid")) {
		lttng_remove_context_field(ctx, field);
		return -EEXIST;
	}
	field->event_field.name = "vtid";
	field->event_field.type.atype = atype_integer;
	field->event_field.type.u.basic.integer.size = sizeof(pid_t) * CHAR_BIT;
	field->event_field.type.u.basic.integer.alignment = lttng_alignof(pid_t) * CHAR_BIT;
	field->event_field.type.u.basic.integer.signedness = lttng_is_signed_type(pid_t);
	field->event_field.type.u.basic.integer.reverse_byte_order = 0;
	field->event_field.type.u.basic.integer.base = 10;
	field->event_field.type.u.basic.integer.encoding = lttng_encode_none;
	field->get_size = vtid_get_size;
	field->record = vtid_record;
	wrapper_vmalloc_sync_all();
	return 0;
}
EXPORT_SYMBOL_GPL(lttng_add_vtid_to_ctx);

MODULE_LICENSE("GPL and additional rights");
MODULE_AUTHOR("Mathieu Desnoyers");
MODULE_DESCRIPTION("Linux Trace Toolkit vTID Context");
MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
	__stringify(LTTNG_MODULES_MINOR_VERSION) "."
	__stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
	LTTNG_MODULES_EXTRAVERSION);
Commit	Line	Data
	1	/*
	2	* lttng-context-vtid.c
	3	*
	4	* LTTng vTID context.
	5	*
	6	* Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	7	*
	8	* This library is free software; you can redistribute it and/or
	9	* modify it under the terms of the GNU Lesser General Public
	10	* License as published by the Free Software Foundation; only
	11	* version 2.1 of the License.
	12	*
	13	* This library is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	16	* Lesser General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU Lesser General Public
	19	* License along with this library; if not, write to the Free Software
	20	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	21	*/
	22
	23	#include <linux/module.h>
	24	#include <linux/slab.h>
	25	#include <linux/sched.h>
	26	#include "lttng-events.h"
	27	#include "wrapper/ringbuffer/frontend_types.h"
	28	#include "wrapper/vmalloc.h"
	29	#include "lttng-tracer.h"
	30
	31	static
	32	size_t vtid_get_size(size_t offset)
	33	{
	34	size_t size = 0;
	35
	36	size += lib_ring_buffer_align(offset, lttng_alignof(pid_t));
	37	size += sizeof(pid_t);
	38	return size;
	39	}
	40
	41	static
	42	void vtid_record(struct lttng_ctx_field *field,
	43	struct lib_ring_buffer_ctx *ctx,
	44	struct lttng_channel *chan)
	45	{
	46	pid_t vtid;
	47
	48	/*
	49	* nsproxy can be NULL when scheduled out of exit.
	50	*/
	51	if (!current->nsproxy)
	52	vtid = 0;
	53	else
	54	vtid = task_pid_vnr(current);
	55	lib_ring_buffer_align_ctx(ctx, lttng_alignof(vtid));
	56	chan->ops->event_write(ctx, &vtid, sizeof(vtid));
	57	}
	58
	59	int lttng_add_vtid_to_ctx(struct lttng_ctx **ctx)
	60	{
	61	struct lttng_ctx_field *field;
	62
	63	field = lttng_append_context(ctx);
	64	if (!field)
	65	return -ENOMEM;
	66	if (lttng_find_context(*ctx, "vtid")) {
	67	lttng_remove_context_field(ctx, field);
	68	return -EEXIST;
	69	}
	70	field->event_field.name = "vtid";
	71	field->event_field.type.atype = atype_integer;
	72	field->event_field.type.u.basic.integer.size = sizeof(pid_t) * CHAR_BIT;
	73	field->event_field.type.u.basic.integer.alignment = lttng_alignof(pid_t) * CHAR_BIT;
	74	field->event_field.type.u.basic.integer.signedness = lttng_is_signed_type(pid_t);
	75	field->event_field.type.u.basic.integer.reverse_byte_order = 0;
	76	field->event_field.type.u.basic.integer.base = 10;
	77	field->event_field.type.u.basic.integer.encoding = lttng_encode_none;
	78	field->get_size = vtid_get_size;
	79	field->record = vtid_record;
	80	wrapper_vmalloc_sync_all();
	81	return 0;
	82	}
	83	EXPORT_SYMBOL_GPL(lttng_add_vtid_to_ctx);
	84
	85	MODULE_LICENSE("GPL and additional rights");
	86	MODULE_AUTHOR("Mathieu Desnoyers");
	87	MODULE_DESCRIPTION("Linux Trace Toolkit vTID Context");
	88	MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
	89	__stringify(LTTNG_MODULES_MINOR_VERSION) "."
	90	__stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
	91	LTTNG_MODULES_EXTRAVERSION);