/usr/src/lttng-modules-2.7.1/lttng-context-procname.c is in lttng-modules-dkms 2.7.1-1.
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 | /*
* lttng-context-procname.c
*
* LTTng procname 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 procname_get_size(size_t offset)
{
size_t size = 0;
size += sizeof(current->comm);
return size;
}
/*
* Racy read of procname. We simply copy its whole array size.
* Races with /proc/<task>/procname write only.
* Otherwise having to take a mutex for each event is cumbersome and
* could lead to crash in IRQ context and deadlock of the lockdep tracer.
*/
static
void procname_record(struct lttng_ctx_field *field,
struct lib_ring_buffer_ctx *ctx,
struct lttng_channel *chan)
{
chan->ops->event_write(ctx, current->comm, sizeof(current->comm));
}
static
void procname_get_value(struct lttng_ctx_field *field,
union lttng_ctx_value *value)
{
value->str = current->comm;
}
int lttng_add_procname_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, "procname")) {
lttng_remove_context_field(ctx, field);
return -EEXIST;
}
field->event_field.name = "procname";
field->event_field.type.atype = atype_array;
field->event_field.type.u.array.elem_type.atype = atype_integer;
field->event_field.type.u.array.elem_type.u.basic.integer.size = sizeof(char) * CHAR_BIT;
field->event_field.type.u.array.elem_type.u.basic.integer.alignment = lttng_alignof(char) * CHAR_BIT;
field->event_field.type.u.array.elem_type.u.basic.integer.signedness = lttng_is_signed_type(char);
field->event_field.type.u.array.elem_type.u.basic.integer.reverse_byte_order = 0;
field->event_field.type.u.array.elem_type.u.basic.integer.base = 10;
field->event_field.type.u.array.elem_type.u.basic.integer.encoding = lttng_encode_UTF8;
field->event_field.type.u.array.length = sizeof(current->comm);
field->get_size = procname_get_size;
field->record = procname_record;
field->get_value = procname_get_value;
lttng_context_update(*ctx);
wrapper_vmalloc_sync_all();
return 0;
}
EXPORT_SYMBOL_GPL(lttng_add_procname_to_ctx);
MODULE_LICENSE("GPL and additional rights");
MODULE_AUTHOR("Mathieu Desnoyers");
MODULE_DESCRIPTION("Linux Trace Toolkit Perf Support");
MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
__stringify(LTTNG_MODULES_MINOR_VERSION) "."
__stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
LTTNG_MODULES_EXTRAVERSION);
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