/*
- * (C) Copyright 2009-2011 -
- * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * lttng-context-vppid.c
*
* LTTng vPPID context.
*
- * Dual LGPL v2.1/GPL v2 license.
+ * 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 <linux/syscalls.h>
-#include "ltt-events.h"
+#include "lttng-events.h"
#include "wrapper/ringbuffer/frontend_types.h"
#include "wrapper/vmalloc.h"
-#include "ltt-tracer.h"
+#include "lttng-tracer.h"
static
size_t vppid_get_size(size_t offset)
{
size_t size = 0;
- size += lib_ring_buffer_align(offset, ltt_alignof(pid_t));
+ size += lib_ring_buffer_align(offset, lttng_alignof(pid_t));
size += sizeof(pid_t);
return size;
}
static
void vppid_record(struct lttng_ctx_field *field,
struct lib_ring_buffer_ctx *ctx,
- struct ltt_channel *chan)
+ struct lttng_channel *chan)
{
+ struct task_struct *parent;
pid_t vppid;
+ /*
+ * current nsproxy can be NULL when scheduled out of exit. pid_vnr uses
+ * the current thread nsproxy to perform the lookup.
+ */
+
+ /*
+ * TODO: when we eventually add RCU subsystem instrumentation,
+ * taking the rcu read lock here will trigger RCU tracing
+ * recursively. We should modify the kernel synchronization so
+ * it synchronizes both for RCU and RCU sched, and rely on
+ * rcu_read_lock_sched_notrace.
+ */
+
rcu_read_lock();
- vppid = task_tgid_vnr(current->real_parent);
+ parent = rcu_dereference(current->real_parent);
+ if (!current->nsproxy)
+ vppid = 0;
+ else
+ vppid = task_tgid_vnr(parent);
rcu_read_unlock();
- lib_ring_buffer_align_ctx(ctx, ltt_alignof(vppid));
+ lib_ring_buffer_align_ctx(ctx, lttng_alignof(vppid));
chan->ops->event_write(ctx, &vppid, sizeof(vppid));
}
field->event_field.name = "vppid";
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 = ltt_alignof(pid_t) * CHAR_BIT;
- field->event_field.type.u.basic.integer.signedness = is_signed_type(pid_t);
+ 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;