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

/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
 *
 * 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 <lttng/events-internal.h>
#include <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_kernel_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_kernel_ctx_field *field,
		struct lttng_probe_ctx *lttng_probe_ctx,
		union lttng_ctx_value *value)
{
	value->s64 = task_tgid_nr(current);
}

static const struct lttng_kernel_ctx_field *ctx_field = lttng_kernel_static_ctx_field(
	lttng_kernel_static_event_field("pid",
		lttng_kernel_static_type_integer_from_type(pid_t, __BYTE_ORDER, 10),
		false, false, false),
	pid_get_size,
	NULL,
	pid_record,
	pid_get_value,
	NULL, NULL);

int lttng_add_pid_to_ctx(struct lttng_kernel_ctx **ctx)
{
	int ret;

	if (lttng_kernel_find_context(*ctx, ctx_field->event_field->name))
		return -EEXIST;
	ret = lttng_kernel_context_append(ctx, ctx_field);
	wrapper_vmalloc_sync_mappings();
	return ret;
}
EXPORT_SYMBOL_GPL(lttng_add_pid_to_ctx);
Commit	Line	Data
	1	/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
	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 <lttng/events-internal.h>
	15	#include <ringbuffer/frontend_types.h>
	16	#include <wrapper/vmalloc.h>
	17	#include <lttng/tracer.h>
	18
	19	static
	20	size_t pid_get_size(size_t offset)
	21	{
	22	size_t size = 0;
	23
	24	size += lib_ring_buffer_align(offset, lttng_alignof(pid_t));
	25	size += sizeof(pid_t);
	26	return size;
	27	}
	28
	29	static
	30	void pid_record(struct lttng_kernel_ctx_field *field,
	31	struct lib_ring_buffer_ctx *ctx,
	32	struct lttng_channel *chan)
	33	{
	34	pid_t pid;
	35
	36	pid = task_tgid_nr(current);
	37	lib_ring_buffer_align_ctx(ctx, lttng_alignof(pid));
	38	chan->ops->event_write(ctx, &pid, sizeof(pid));
	39	}
	40
	41	static
	42	void pid_get_value(struct lttng_kernel_ctx_field *field,
	43	struct lttng_probe_ctx *lttng_probe_ctx,
	44	union lttng_ctx_value *value)
	45	{
	46	value->s64 = task_tgid_nr(current);
	47	}
	48
	49	static const struct lttng_kernel_ctx_field *ctx_field = lttng_kernel_static_ctx_field(
	50	lttng_kernel_static_event_field("pid",
	51	lttng_kernel_static_type_integer_from_type(pid_t, __BYTE_ORDER, 10),
	52	false, false, false),
	53	pid_get_size,
	54	NULL,
	55	pid_record,
	56	pid_get_value,
	57	NULL, NULL);
	58
	59	int lttng_add_pid_to_ctx(struct lttng_kernel_ctx **ctx)
	60	{
	61	int ret;
	62
	63	if (lttng_kernel_find_context(*ctx, ctx_field->event_field->name))
	64	return -EEXIST;
	65	ret = lttng_kernel_context_append(ctx, ctx_field);
	66	wrapper_vmalloc_sync_mappings();
	67	return ret;
	68	}
	69	EXPORT_SYMBOL_GPL(lttng_add_pid_to_ctx);