/usr/src/lttng-modules-2.5.1/lttng-context-vppid.c is in lttng-modules-dkms 2.5.1-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 | /*
* lttng-context-vppid.c
*
* LTTng vPPID 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 <linux/syscalls.h>
#include "lttng-events.h"
#include "wrapper/ringbuffer/frontend_types.h"
#include "wrapper/vmalloc.h"
#include "lttng-tracer.h"
static
size_t vppid_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 vppid_record(struct lttng_ctx_field *field,
struct lib_ring_buffer_ctx *ctx,
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();
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, lttng_alignof(vppid));
chan->ops->event_write(ctx, &vppid, sizeof(vppid));
}
int lttng_add_vppid_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, "vppid")) {
lttng_remove_context_field(ctx, field);
return -EEXIST;
}
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 = 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 = vppid_get_size;
field->record = vppid_record;
wrapper_vmalloc_sync_all();
return 0;
}
EXPORT_SYMBOL_GPL(lttng_add_vppid_to_ctx);
MODULE_LICENSE("GPL and additional rights");
MODULE_AUTHOR("Mathieu Desnoyers");
MODULE_DESCRIPTION("Linux Trace Toolkit vPPID Context");
MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
__stringify(LTTNG_MODULES_MINOR_VERSION) "."
__stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
LTTNG_MODULES_EXTRAVERSION);
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