/*

* lttng-context-vpid.c

*

* LTTng vPID context.

*

* Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

*

* This library is free software; you can redistribute it and/or

* modify it under the terms of the GNU Lesser General Public

* License as published by the Free Software Foundation; only

* version 2.1 of the License.

*

* This library is distributed in the hope that it will be useful,

* but WITHOUT ANY WARRANTY; without even the implied warranty of

* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

* Lesser General Public License for more details.

*

* You should have received a copy of the GNU Lesser General Public

* License along with this library; if not, write to the Free Software

* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

*/

#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 vpid_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 vpid_record(struct lttng_ctx_field *field,

struct lib_ring_buffer_ctx *ctx,

struct lttng_channel *chan)

{

pid_t vpid;

/*

* nsproxy can be NULL when scheduled out of exit.

*/

if (!current->nsproxy)

vpid = 0;

else

vpid = task_tgid_vnr(current);

lib_ring_buffer_align_ctx(ctx, lttng_alignof(vpid));

chan->ops->event_write(ctx, &vpid, sizeof(vpid));

}

static

void vpid_get_value(struct lttng_ctx_field *field,

struct lttng_probe_ctx *lttng_probe_ctx,

union lttng_ctx_value *value)

{

pid_t vpid;

/*

* nsproxy can be NULL when scheduled out of exit.

*/

if (!current->nsproxy)

vpid = 0;

else

vpid = task_tgid_vnr(current);

value->s64 = vpid;

}

int lttng_add_vpid_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, "vpid")) {

lttng_remove_context_field(ctx, field);

return -EEXIST;

}

field->event_field.name = "vpid";

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 = vpid_get_size;

field->record = vpid_record;

field->get_value = vpid_get_value;

lttng_context_update(*ctx);

wrapper_vmalloc_sync_all();

return 0;

}

EXPORT_SYMBOL_GPL(lttng_add_vpid_to_ctx);