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

/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
 *
 * lttng-context-pid.c
 *
 * LTTng PID 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 <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_mappings();
	return 0;
}
EXPORT_SYMBOL_GPL(lttng_add_pid_to_ctx);
Commit	Line	Data
	1	/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
	2	*
	3	* lttng-context-pid.c
	4	*
	5	* LTTng PID 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 <wrapper/vmalloc.h>
	16	#include <lttng-tracer.h>
	17
	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, lttng_alignof(pid_t));
	24	size += sizeof(pid_t);
	25	return size;
	26	}
	27
	28	static
	29	void pid_record(struct lttng_ctx_field *field,
	30	struct lib_ring_buffer_ctx *ctx,
	31	struct lttng_channel *chan)
	32	{
	33	pid_t pid;
	34
	35	pid = task_tgid_nr(current);
	36	lib_ring_buffer_align_ctx(ctx, lttng_alignof(pid));
	37	chan->ops->event_write(ctx, &pid, sizeof(pid));
	38	}
	39
	40	static
	41	void pid_get_value(struct lttng_ctx_field *field,
	42	struct lttng_probe_ctx *lttng_probe_ctx,
	43	union lttng_ctx_value *value)
	44	{
	45	value->s64 = task_tgid_nr(current);
	46	}
	47
	48	int lttng_add_pid_to_ctx(struct lttng_ctx **ctx)
	49	{
	50	struct lttng_ctx_field *field;
	51
	52	field = lttng_append_context(ctx);
	53	if (!field)
	54	return -ENOMEM;
	55	if (lttng_find_context(*ctx, "pid")) {
	56	lttng_remove_context_field(ctx, field);
	57	return -EEXIST;
	58	}
	59	field->event_field.name = "pid";
	60	field->event_field.type.atype = atype_integer;
	61	field->event_field.type.u.basic.integer.size = sizeof(pid_t) * CHAR_BIT;
	62	field->event_field.type.u.basic.integer.alignment = lttng_alignof(pid_t) * CHAR_BIT;
	63	field->event_field.type.u.basic.integer.signedness = lttng_is_signed_type(pid_t);
	64	field->event_field.type.u.basic.integer.reverse_byte_order = 0;
	65	field->event_field.type.u.basic.integer.base = 10;
	66	field->event_field.type.u.basic.integer.encoding = lttng_encode_none;
	67	field->get_size = pid_get_size;
	68	field->record = pid_record;
	69	field->get_value = pid_get_value;
	70	lttng_context_update(*ctx);
	71	wrapper_vmalloc_sync_mappings();
	72	return 0;
	73	}
	74	EXPORT_SYMBOL_GPL(lttng_add_pid_to_ctx);