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

/*
 * lttng-context-pid.c
 *
 * LTTng PID 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 pid_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 pid_record(struct lttng_ctx_field *field,
		struct lib_ring_buffer_ctx *ctx,
		struct lttng_channel *chan)
{
	pid_t pid;

	pid = task_tgid_nr(current);
	lib_ring_buffer_align_ctx(ctx, lttng_alignof(pid));
	chan->ops->event_write(ctx, &pid, sizeof(pid));
}

static
void pid_get_value(struct lttng_ctx_field *field,
		struct lttng_probe_ctx *lttng_probe_ctx,
		union lttng_ctx_value *value)
{
	value->s64 = task_tgid_nr(current);
}

int lttng_add_pid_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, "pid")) {
		lttng_remove_context_field(ctx, field);
		return -EEXIST;
	}
	field->event_field.name = "pid";
	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 = pid_get_size;
	field->record = pid_record;
	field->get_value = pid_get_value;
	lttng_context_update(*ctx);
	wrapper_vmalloc_sync_all();
	return 0;
}
EXPORT_SYMBOL_GPL(lttng_add_pid_to_ctx);
Commit	Line	Data
9e7e4892	1	/*
886d51a3	2	* lttng-context-pid.c
9e7e4892 MD	3	*
	4	* LTTng PID 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
9e7e4892 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>
9e7e4892	30
f1676205 MD	31	static
	32	size_t pid_get_size(size_t offset)
	33	{
	34	size_t size = 0;
	35
a90917c3	36	size += lib_ring_buffer_align(offset, lttng_alignof(pid_t));
f1676205 MD	37	size += sizeof(pid_t);
	38	return size;
	39	}
	40
9e7e4892 MD	41	static
	42	void pid_record(struct lttng_ctx_field *field,
	43	struct lib_ring_buffer_ctx *ctx,
a90917c3	44	struct lttng_channel *chan)
9e7e4892 MD	45	{
	46	pid_t pid;
	47
b64bc438	48	pid = task_tgid_nr(current);
a90917c3	49	lib_ring_buffer_align_ctx(ctx, lttng_alignof(pid));
9e7e4892 MD	50	chan->ops->event_write(ctx, &pid, sizeof(pid));
	51	}
	52
f127e61e MD	53	static
f127e61e MD	54	void pid_get_value(struct lttng_ctx_field *field,
79150a49	55	struct lttng_probe_ctx *lttng_probe_ctx,
f127e61e MD	56	union lttng_ctx_value *value)
	57	{
	58	value->s64 = task_tgid_nr(current);
	59	}
	60
9e7e4892 MD	61	int lttng_add_pid_to_ctx(struct lttng_ctx **ctx)
	62	{
	63	struct lttng_ctx_field *field;
9e7e4892 MD	64
	65	field = lttng_append_context(ctx);
	66	if (!field)
09fec6b4	67	return -ENOMEM;
44252f0f MD	68	if (lttng_find_context(*ctx, "pid")) {
	69	lttng_remove_context_field(ctx, field);
	70	return -EEXIST;
	71	}
8070f5c0 MD	72	field->event_field.name = "pid";
	73	field->event_field.type.atype = atype_integer;
	74	field->event_field.type.u.basic.integer.size = sizeof(pid_t) * CHAR_BIT;
a90917c3	75	field->event_field.type.u.basic.integer.alignment = lttng_alignof(pid_t) * CHAR_BIT;
06254b0f	76	field->event_field.type.u.basic.integer.signedness = lttng_is_signed_type(pid_t);
8070f5c0 MD	77	field->event_field.type.u.basic.integer.reverse_byte_order = 0;
	78	field->event_field.type.u.basic.integer.base = 10;
	79	field->event_field.type.u.basic.integer.encoding = lttng_encode_none;
f1676205 MD	80	field->get_size = pid_get_size;
f1676205 MD	81	field->record = pid_record;
f127e61e	82	field->get_value = pid_get_value;
a9dd15da	83	lttng_context_update(*ctx);
9e7e4892 MD	84	wrapper_vmalloc_sync_all();
	85	return 0;
	86	}
8070f5c0	87	EXPORT_SYMBOL_GPL(lttng_add_pid_to_ctx);