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

/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
 *
 * lttng-context-veuid.c
 *
 * LTTng namespaced effective user ID context.
 *
 * Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *               2019 Michael Jeanson <mjeanson@efficios.com>
 *
 */

#include <linux/module.h>
#include <linux/sched.h>
#include <lttng-events.h>
#include <lttng-tracer.h>
#include <wrapper/ringbuffer/frontend_types.h>
#include <wrapper/vmalloc.h>
#include <wrapper/user_namespace.h>

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

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

static
void veuid_record(struct lttng_ctx_field *field,
		 struct lib_ring_buffer_ctx *ctx,
		 struct lttng_channel *chan)
{
	uid_t veuid;

	veuid = lttng_current_veuid();
	lib_ring_buffer_align_ctx(ctx, lttng_alignof(veuid));
	chan->ops->event_write(ctx, &veuid, sizeof(veuid));
}

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

int lttng_add_veuid_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, "veuid")) {
		lttng_remove_context_field(ctx, field);
		return -EEXIST;
	}
	field->event_field.name = "veuid";
	field->event_field.type.atype = atype_integer;
	field->event_field.type.u.basic.integer.size = sizeof(uid_t) * CHAR_BIT;
	field->event_field.type.u.basic.integer.alignment = lttng_alignof(uid_t) * CHAR_BIT;
	field->event_field.type.u.basic.integer.signedness = lttng_is_signed_type(uid_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 = veuid_get_size;
	field->record = veuid_record;
	field->get_value = veuid_get_value;
	lttng_context_update(*ctx);
	wrapper_vmalloc_sync_mappings();
	return 0;
}
EXPORT_SYMBOL_GPL(lttng_add_veuid_to_ctx);
Commit	Line	Data
	1	/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
	2	*
	3	* lttng-context-veuid.c
	4	*
	5	* LTTng namespaced effective user ID context.
	6	*
	7	* Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	8	* 2019 Michael Jeanson <mjeanson@efficios.com>
	9	*
	10	*/
	11
	12	#include <linux/module.h>
	13	#include <linux/sched.h>
	14	#include <lttng-events.h>
	15	#include <lttng-tracer.h>
	16	#include <wrapper/ringbuffer/frontend_types.h>
	17	#include <wrapper/vmalloc.h>
	18	#include <wrapper/user_namespace.h>
	19
	20	static
	21	size_t veuid_get_size(size_t offset)
	22	{
	23	size_t size = 0;
	24
	25	size += lib_ring_buffer_align(offset, lttng_alignof(uid_t));
	26	size += sizeof(uid_t);
	27	return size;
	28	}
	29
	30	static
	31	void veuid_record(struct lttng_ctx_field *field,
	32	struct lib_ring_buffer_ctx *ctx,
	33	struct lttng_channel *chan)
	34	{
	35	uid_t veuid;
	36
	37	veuid = lttng_current_veuid();
	38	lib_ring_buffer_align_ctx(ctx, lttng_alignof(veuid));
	39	chan->ops->event_write(ctx, &veuid, sizeof(veuid));
	40	}
	41
	42	static
	43	void veuid_get_value(struct lttng_ctx_field *field,
	44	struct lttng_probe_ctx *lttng_probe_ctx,
	45	union lttng_ctx_value *value)
	46	{
	47	value->s64 = lttng_current_veuid();
	48	}
	49
	50	int lttng_add_veuid_to_ctx(struct lttng_ctx **ctx)
	51	{
	52	struct lttng_ctx_field *field;
	53
	54	field = lttng_append_context(ctx);
	55	if (!field)
	56	return -ENOMEM;
	57	if (lttng_find_context(*ctx, "veuid")) {
	58	lttng_remove_context_field(ctx, field);
	59	return -EEXIST;
	60	}
	61	field->event_field.name = "veuid";
	62	field->event_field.type.atype = atype_integer;
	63	field->event_field.type.u.basic.integer.size = sizeof(uid_t) * CHAR_BIT;
	64	field->event_field.type.u.basic.integer.alignment = lttng_alignof(uid_t) * CHAR_BIT;
	65	field->event_field.type.u.basic.integer.signedness = lttng_is_signed_type(uid_t);
	66	field->event_field.type.u.basic.integer.reverse_byte_order = 0;
	67	field->event_field.type.u.basic.integer.base = 10;
	68	field->event_field.type.u.basic.integer.encoding = lttng_encode_none;
	69	field->get_size = veuid_get_size;
	70	field->record = veuid_record;
	71	field->get_value = veuid_get_value;
	72	lttng_context_update(*ctx);
	73	wrapper_vmalloc_sync_mappings();
	74	return 0;
	75	}
	76	EXPORT_SYMBOL_GPL(lttng_add_veuid_to_ctx);