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

/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
 *
 * lttng-context-vtid.c
 *
 * LTTng vTID 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 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_mappings();
	return 0;
}
EXPORT_SYMBOL_GPL(lttng_add_vtid_to_ctx);
Commit	Line	Data
9f36eaed MJ	1	/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
9f36eaed MJ	2	*
886d51a3	3	* lttng-context-vtid.c
b64bc438 MD	4	*
	5	* LTTng vTID context.
	6	*
886d51a3	7	* Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
b64bc438 MD	8	*/
	9
	10	#include <linux/module.h>
	11	#include <linux/slab.h>
	12	#include <linux/sched.h>
241ae9a8 MD	13	#include <lttng-events.h>
	14	#include <wrapper/ringbuffer/frontend_types.h>
	15	#include <wrapper/vmalloc.h>
	16	#include <lttng-tracer.h>
b64bc438 MD	17
	18	static
	19	size_t vtid_get_size(size_t offset)
	20	{
	21	size_t size = 0;
	22
a90917c3	23	size += lib_ring_buffer_align(offset, lttng_alignof(pid_t));
b64bc438 MD	24	size += sizeof(pid_t);
	25	return size;
	26	}
	27
	28	static
	29	void vtid_record(struct lttng_ctx_field *field,
	30	struct lib_ring_buffer_ctx *ctx,
a90917c3	31	struct lttng_channel *chan)
b64bc438 MD	32	{
	33	pid_t vtid;
	34
90f96adf MD	35	/*
	36	* nsproxy can be NULL when scheduled out of exit.
	37	*/
	38	if (!current->nsproxy)
	39	vtid = 0;
	40	else
	41	vtid = task_pid_vnr(current);
a90917c3	42	lib_ring_buffer_align_ctx(ctx, lttng_alignof(vtid));
b64bc438 MD	43	chan->ops->event_write(ctx, &vtid, sizeof(vtid));
	44	}
	45
f127e61e MD	46	static
f127e61e MD	47	void vtid_get_value(struct lttng_ctx_field *field,
79150a49	48	struct lttng_probe_ctx *lttng_probe_ctx,
f127e61e MD	49	union lttng_ctx_value *value)
	50	{
	51	pid_t vtid;
	52
	53	/*
	54	* nsproxy can be NULL when scheduled out of exit.
	55	*/
	56	if (!current->nsproxy)
	57	vtid = 0;
	58	else
	59	vtid = task_pid_vnr(current);
	60	value->s64 = vtid;
	61	}
	62
b64bc438 MD	63	int lttng_add_vtid_to_ctx(struct lttng_ctx **ctx)
	64	{
	65	struct lttng_ctx_field *field;
b64bc438 MD	66
	67	field = lttng_append_context(ctx);
	68	if (!field)
09fec6b4	69	return -ENOMEM;
44252f0f MD	70	if (lttng_find_context(*ctx, "vtid")) {
	71	lttng_remove_context_field(ctx, field);
	72	return -EEXIST;
	73	}
b64bc438 MD	74	field->event_field.name = "vtid";
	75	field->event_field.type.atype = atype_integer;
	76	field->event_field.type.u.basic.integer.size = sizeof(pid_t) * CHAR_BIT;
a90917c3	77	field->event_field.type.u.basic.integer.alignment = lttng_alignof(pid_t) * CHAR_BIT;
06254b0f	78	field->event_field.type.u.basic.integer.signedness = lttng_is_signed_type(pid_t);
b64bc438 MD	79	field->event_field.type.u.basic.integer.reverse_byte_order = 0;
	80	field->event_field.type.u.basic.integer.base = 10;
	81	field->event_field.type.u.basic.integer.encoding = lttng_encode_none;
	82	field->get_size = vtid_get_size;
	83	field->record = vtid_record;
f127e61e	84	field->get_value = vtid_get_value;
a9dd15da	85	lttng_context_update(*ctx);
da0fcb14	86	wrapper_vmalloc_sync_mappings();
b64bc438 MD	87	return 0;
	88	}
	89	EXPORT_SYMBOL_GPL(lttng_add_vtid_to_ctx);