Commit | Line | Data |
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b64bc438 | 1 | /* |
886d51a3 | 2 | * lttng-context-ppid.c |
b64bc438 MD |
3 | * |
4 | * LTTng PPID context. | |
5 | * | |
886d51a3 MD |
6 | * Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
7 | * | |
8 | * This library is free software; you can redistribute it and/or | |
9 | * modify it under the terms of the GNU Lesser General Public | |
10 | * License as published by the Free Software Foundation; only | |
11 | * version 2.1 of the License. | |
12 | * | |
13 | * This library is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | * Lesser General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU Lesser General Public | |
19 | * License along with this library; if not, write to the Free Software | |
20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
b64bc438 MD |
21 | */ |
22 | ||
23 | #include <linux/module.h> | |
24 | #include <linux/slab.h> | |
25 | #include <linux/sched.h> | |
26 | #include <linux/syscalls.h> | |
a90917c3 | 27 | #include "lttng-events.h" |
b64bc438 MD |
28 | #include "wrapper/ringbuffer/frontend_types.h" |
29 | #include "wrapper/vmalloc.h" | |
a90917c3 | 30 | #include "lttng-tracer.h" |
b64bc438 MD |
31 | |
32 | static | |
33 | size_t ppid_get_size(size_t offset) | |
34 | { | |
35 | size_t size = 0; | |
36 | ||
a90917c3 | 37 | size += lib_ring_buffer_align(offset, lttng_alignof(pid_t)); |
b64bc438 MD |
38 | size += sizeof(pid_t); |
39 | return size; | |
40 | } | |
41 | ||
42 | static | |
43 | void ppid_record(struct lttng_ctx_field *field, | |
44 | struct lib_ring_buffer_ctx *ctx, | |
a90917c3 | 45 | struct lttng_channel *chan) |
b64bc438 MD |
46 | { |
47 | pid_t ppid; | |
48 | ||
49 | rcu_read_lock(); | |
50 | ppid = task_tgid_nr(current->real_parent); | |
51 | rcu_read_unlock(); | |
a90917c3 | 52 | lib_ring_buffer_align_ctx(ctx, lttng_alignof(ppid)); |
b64bc438 MD |
53 | chan->ops->event_write(ctx, &ppid, sizeof(ppid)); |
54 | } | |
55 | ||
56 | int lttng_add_ppid_to_ctx(struct lttng_ctx **ctx) | |
57 | { | |
58 | struct lttng_ctx_field *field; | |
b64bc438 MD |
59 | |
60 | field = lttng_append_context(ctx); | |
61 | if (!field) | |
09fec6b4 | 62 | return -ENOMEM; |
44252f0f MD |
63 | if (lttng_find_context(*ctx, "ppid")) { |
64 | lttng_remove_context_field(ctx, field); | |
65 | return -EEXIST; | |
66 | } | |
b64bc438 MD |
67 | field->event_field.name = "ppid"; |
68 | field->event_field.type.atype = atype_integer; | |
69 | field->event_field.type.u.basic.integer.size = sizeof(pid_t) * CHAR_BIT; | |
a90917c3 | 70 | field->event_field.type.u.basic.integer.alignment = lttng_alignof(pid_t) * CHAR_BIT; |
b64bc438 MD |
71 | field->event_field.type.u.basic.integer.signedness = is_signed_type(pid_t); |
72 | field->event_field.type.u.basic.integer.reverse_byte_order = 0; | |
73 | field->event_field.type.u.basic.integer.base = 10; | |
74 | field->event_field.type.u.basic.integer.encoding = lttng_encode_none; | |
75 | field->get_size = ppid_get_size; | |
76 | field->record = ppid_record; | |
77 | wrapper_vmalloc_sync_all(); | |
78 | return 0; | |
79 | } | |
80 | EXPORT_SYMBOL_GPL(lttng_add_ppid_to_ctx); | |
81 | ||
82 | MODULE_LICENSE("GPL and additional rights"); | |
83 | MODULE_AUTHOR("Mathieu Desnoyers"); | |
84 | MODULE_DESCRIPTION("Linux Trace Toolkit PPID Context"); |