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

/*
 * (C) Copyright	2009-2011 -
 * 		Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * LTTng PID context.
 *
 * Dual LGPL v2.1/GPL v2 license.
 */

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

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

	size += lib_ring_buffer_align(offset, ltt_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 ltt_channel *chan)
{
	pid_t pid;

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

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 = ltt_alignof(pid_t) * CHAR_BIT;
	field->event_field.type.u.basic.integer.signedness = 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;
	wrapper_vmalloc_sync_all();
	return 0;
}
EXPORT_SYMBOL_GPL(lttng_add_pid_to_ctx);

MODULE_LICENSE("GPL and additional rights");
MODULE_AUTHOR("Mathieu Desnoyers");
MODULE_DESCRIPTION("Linux Trace Toolkit PID Context");
Commit	Line	Data
9e7e4892 MD	1	/*
	2	* (C) Copyright 2009-2011 -
	3	* Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	4	*
	5	* LTTng PID context.
	6	*
	7	* Dual LGPL v2.1/GPL v2 license.
	8	*/
	9
	10	#include <linux/module.h>
	11	#include <linux/slab.h>
	12	#include <linux/sched.h>
becb1a77 MD	13	#include "ltt-events.h"
	14	#include "wrapper/ringbuffer/frontend_types.h"
	15	#include "wrapper/vmalloc.h"
	16	#include "ltt-tracer.h"
9e7e4892	17
f1676205 MD	18	static
	19	size_t pid_get_size(size_t offset)
	20	{
	21	size_t size = 0;
	22
	23	size += lib_ring_buffer_align(offset, ltt_alignof(pid_t));
	24	size += sizeof(pid_t);
	25	return size;
	26	}
	27
9e7e4892 MD	28	static
	29	void pid_record(struct lttng_ctx_field *field,
	30	struct lib_ring_buffer_ctx *ctx,
	31	struct ltt_channel *chan)
	32	{
	33	pid_t pid;
	34
b64bc438	35	pid = task_tgid_nr(current);
9e7e4892 MD	36	lib_ring_buffer_align_ctx(ctx, ltt_alignof(pid));
	37	chan->ops->event_write(ctx, &pid, sizeof(pid));
	38	}
	39
	40	int lttng_add_pid_to_ctx(struct lttng_ctx **ctx)
	41	{
	42	struct lttng_ctx_field *field;
9e7e4892 MD	43
	44	field = lttng_append_context(ctx);
	45	if (!field)
09fec6b4	46	return -ENOMEM;
44252f0f MD	47	if (lttng_find_context(*ctx, "pid")) {
	48	lttng_remove_context_field(ctx, field);
	49	return -EEXIST;
	50	}
8070f5c0 MD	51	field->event_field.name = "pid";
	52	field->event_field.type.atype = atype_integer;
	53	field->event_field.type.u.basic.integer.size = sizeof(pid_t) * CHAR_BIT;
	54	field->event_field.type.u.basic.integer.alignment = ltt_alignof(pid_t) * CHAR_BIT;
	55	field->event_field.type.u.basic.integer.signedness = is_signed_type(pid_t);
	56	field->event_field.type.u.basic.integer.reverse_byte_order = 0;
	57	field->event_field.type.u.basic.integer.base = 10;
	58	field->event_field.type.u.basic.integer.encoding = lttng_encode_none;
f1676205 MD	59	field->get_size = pid_get_size;
f1676205 MD	60	field->record = pid_record;
9e7e4892 MD	61	wrapper_vmalloc_sync_all();
	62	return 0;
	63	}
8070f5c0	64	EXPORT_SYMBOL_GPL(lttng_add_pid_to_ctx);
9e7e4892 MD	65
	66	MODULE_LICENSE("GPL and additional rights");
	67	MODULE_AUTHOR("Mathieu Desnoyers");
53f1f0ca	68	MODULE_DESCRIPTION("Linux Trace Toolkit PID Context");