[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));
}

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

	/*
	 * nsproxy can be NULL when scheduled out of exit.
	 */
	if (!current->nsproxy)
		vtid = 0;
	else
		vtid = task_pid_vnr(current);
	value->s64 = 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;
	field->get_value = vtid_get_value;
	lttng_context_update(*ctx);
	wrapper_vmalloc_sync_all();
	return 0;
}
EXPORT_SYMBOL_GPL(lttng_add_vtid_to_ctx);
Commit	Line	Data
b64bc438	1	/*
886d51a3	2	* lttng-context-vtid.c
b64bc438 MD	3	*
	4	* LTTng vTID context.
	5	*
886d51a3 MD	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
b64bc438 MD	21	*/
	22
	23	#include <linux/module.h>
	24	#include <linux/slab.h>
	25	#include <linux/sched.h>
241ae9a8 MD	26	#include <lttng-events.h>
	27	#include <wrapper/ringbuffer/frontend_types.h>
	28	#include <wrapper/vmalloc.h>
	29	#include <lttng-tracer.h>
b64bc438 MD	30
	31	static
	32	size_t vtid_get_size(size_t offset)
	33	{
	34	size_t size = 0;
	35
a90917c3	36	size += lib_ring_buffer_align(offset, lttng_alignof(pid_t));
b64bc438 MD	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,
a90917c3	44	struct lttng_channel *chan)
b64bc438 MD	45	{
	46	pid_t vtid;
	47
90f96adf MD	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);
a90917c3	55	lib_ring_buffer_align_ctx(ctx, lttng_alignof(vtid));
b64bc438 MD	56	chan->ops->event_write(ctx, &vtid, sizeof(vtid));
	57	}
	58
f127e61e MD	59	static
f127e61e MD	60	void vtid_get_value(struct lttng_ctx_field *field,
79150a49	61	struct lttng_probe_ctx *lttng_probe_ctx,
f127e61e MD	62	union lttng_ctx_value *value)
	63	{
	64	pid_t vtid;
	65
	66	/*
	67	* nsproxy can be NULL when scheduled out of exit.
	68	*/
	69	if (!current->nsproxy)
	70	vtid = 0;
	71	else
	72	vtid = task_pid_vnr(current);
	73	value->s64 = vtid;
	74	}
	75
b64bc438 MD	76	int lttng_add_vtid_to_ctx(struct lttng_ctx **ctx)
	77	{
	78	struct lttng_ctx_field *field;
b64bc438 MD	79
	80	field = lttng_append_context(ctx);
	81	if (!field)
09fec6b4	82	return -ENOMEM;
44252f0f MD	83	if (lttng_find_context(*ctx, "vtid")) {
	84	lttng_remove_context_field(ctx, field);
	85	return -EEXIST;
	86	}
b64bc438 MD	87	field->event_field.name = "vtid";
	88	field->event_field.type.atype = atype_integer;
	89	field->event_field.type.u.basic.integer.size = sizeof(pid_t) * CHAR_BIT;
a90917c3	90	field->event_field.type.u.basic.integer.alignment = lttng_alignof(pid_t) * CHAR_BIT;
06254b0f	91	field->event_field.type.u.basic.integer.signedness = lttng_is_signed_type(pid_t);
b64bc438 MD	92	field->event_field.type.u.basic.integer.reverse_byte_order = 0;
	93	field->event_field.type.u.basic.integer.base = 10;
	94	field->event_field.type.u.basic.integer.encoding = lttng_encode_none;
	95	field->get_size = vtid_get_size;
	96	field->record = vtid_record;
f127e61e	97	field->get_value = vtid_get_value;
a9dd15da	98	lttng_context_update(*ctx);
b64bc438 MD	99	wrapper_vmalloc_sync_all();
	100	return 0;
	101	}
	102	EXPORT_SYMBOL_GPL(lttng_add_vtid_to_ctx);