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

/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
 *
 * lttng-context-prio.c
 *
 * LTTng priority 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 <wrapper/kallsyms.h>
#include <lttng-tracer.h>

static
int (*wrapper_task_prio_sym)(struct task_struct *t);

int wrapper_task_prio_init(void)
{
	wrapper_task_prio_sym = (void *) kallsyms_lookup_funcptr("task_prio");
	if (!wrapper_task_prio_sym) {
		printk(KERN_WARNING "LTTng: task_prio symbol lookup failed.\n");
		return -EINVAL;
	}
	return 0;
}

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

	size += lib_ring_buffer_align(offset, lttng_alignof(int));
	size += sizeof(int);
	return size;
}

static
void prio_record(struct lttng_ctx_field *field,
		struct lib_ring_buffer_ctx *ctx,
		struct lttng_channel *chan)
{
	int prio;

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

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

int lttng_add_prio_to_ctx(struct lttng_ctx **ctx)
{
	struct lttng_ctx_field *field;
	int ret;

	if (!wrapper_task_prio_sym) {
		ret = wrapper_task_prio_init();
		if (ret)
			return ret;
	}

	field = lttng_append_context(ctx);
	if (!field)
		return -ENOMEM;
	if (lttng_find_context(*ctx, "prio")) {
		lttng_remove_context_field(ctx, field);
		return -EEXIST;
	}
	field->event_field.name = "prio";
	field->event_field.type.atype = atype_integer;
	field->event_field.type.u.basic.integer.size = sizeof(int) * CHAR_BIT;
	field->event_field.type.u.basic.integer.alignment = lttng_alignof(int) * CHAR_BIT;
	field->event_field.type.u.basic.integer.signedness = lttng_is_signed_type(int);
	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 = prio_get_size;
	field->record = prio_record;
	field->get_value = prio_get_value;
	lttng_context_update(*ctx);
	wrapper_vmalloc_sync_all();
	return 0;
}
EXPORT_SYMBOL_GPL(lttng_add_prio_to_ctx);
Commit	Line	Data
b7cdc182	1	/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
9f36eaed	2	*
886d51a3	3	* lttng-context-prio.c
a8ad3613 MD	4	*
	5	* LTTng priority context.
	6	*
886d51a3	7	* Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
a8ad3613 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 <wrapper/kallsyms.h>
	17	#include <lttng-tracer.h>
a8ad3613	18
979133c5 MD	19	static
	20	int (wrapper_task_prio_sym)(struct task_struct t);
	21
	22	int wrapper_task_prio_init(void)
	23	{
c539a324	24	wrapper_task_prio_sym = (void *) kallsyms_lookup_funcptr("task_prio");
979133c5 MD	25	if (!wrapper_task_prio_sym) {
	26	printk(KERN_WARNING "LTTng: task_prio symbol lookup failed.\n");
	27	return -EINVAL;
	28	}
	29	return 0;
	30	}
	31
a8ad3613 MD	32	static
	33	size_t prio_get_size(size_t offset)
	34	{
	35	size_t size = 0;
	36
a90917c3	37	size += lib_ring_buffer_align(offset, lttng_alignof(int));
a8ad3613 MD	38	size += sizeof(int);
	39	return size;
	40	}
	41
	42	static
	43	void prio_record(struct lttng_ctx_field *field,
	44	struct lib_ring_buffer_ctx *ctx,
a90917c3	45	struct lttng_channel *chan)
a8ad3613 MD	46	{
	47	int prio;
	48
8fefc8a2	49	prio = wrapper_task_prio_sym(current);
a90917c3	50	lib_ring_buffer_align_ctx(ctx, lttng_alignof(prio));
53f1f0ca	51	chan->ops->event_write(ctx, &prio, sizeof(prio));
a8ad3613 MD	52	}
a8ad3613 MD	53
f127e61e MD	54	static
f127e61e MD	55	void prio_get_value(struct lttng_ctx_field *field,
79150a49	56	struct lttng_probe_ctx *lttng_probe_ctx,
f127e61e MD	57	union lttng_ctx_value *value)
	58	{
	59	value->s64 = wrapper_task_prio_sym(current);
	60	}
	61
a8ad3613 MD	62	int lttng_add_prio_to_ctx(struct lttng_ctx **ctx)
	63	{
	64	struct lttng_ctx_field *field;
	65	int ret;
	66
979133c5 MD	67	if (!wrapper_task_prio_sym) {
	68	ret = wrapper_task_prio_init();
	69	if (ret)
	70	return ret;
	71	}
	72
a8ad3613 MD	73	field = lttng_append_context(ctx);
a8ad3613 MD	74	if (!field)
09fec6b4	75	return -ENOMEM;
44252f0f MD	76	if (lttng_find_context(*ctx, "prio")) {
	77	lttng_remove_context_field(ctx, field);
	78	return -EEXIST;
	79	}
a8ad3613 MD	80	field->event_field.name = "prio";
	81	field->event_field.type.atype = atype_integer;
	82	field->event_field.type.u.basic.integer.size = sizeof(int) * CHAR_BIT;
a90917c3	83	field->event_field.type.u.basic.integer.alignment = lttng_alignof(int) * CHAR_BIT;
06254b0f	84	field->event_field.type.u.basic.integer.signedness = lttng_is_signed_type(int);
a8ad3613 MD	85	field->event_field.type.u.basic.integer.reverse_byte_order = 0;
	86	field->event_field.type.u.basic.integer.base = 10;
	87	field->event_field.type.u.basic.integer.encoding = lttng_encode_none;
	88	field->get_size = prio_get_size;
	89	field->record = prio_record;
f127e61e	90	field->get_value = prio_get_value;
a9dd15da	91	lttng_context_update(*ctx);
a8ad3613 MD	92	wrapper_vmalloc_sync_all();
	93	return 0;
	94	}
	95	EXPORT_SYMBOL_GPL(lttng_add_prio_to_ctx);