Commit | Line | Data |
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9e7e4892 | 1 | /* |
886d51a3 | 2 | * lttng-context-pid.c |
9e7e4892 MD |
3 | * |
4 | * LTTng PID 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 | |
9e7e4892 MD |
21 | */ |
22 | ||
23 | #include <linux/module.h> | |
24 | #include <linux/slab.h> | |
25 | #include <linux/sched.h> | |
a90917c3 | 26 | #include "lttng-events.h" |
becb1a77 MD |
27 | #include "wrapper/ringbuffer/frontend_types.h" |
28 | #include "wrapper/vmalloc.h" | |
a90917c3 | 29 | #include "lttng-tracer.h" |
9e7e4892 | 30 | |
f1676205 MD |
31 | static |
32 | size_t pid_get_size(size_t offset) | |
33 | { | |
34 | size_t size = 0; | |
35 | ||
a90917c3 | 36 | size += lib_ring_buffer_align(offset, lttng_alignof(pid_t)); |
f1676205 MD |
37 | size += sizeof(pid_t); |
38 | return size; | |
39 | } | |
40 | ||
9e7e4892 MD |
41 | static |
42 | void pid_record(struct lttng_ctx_field *field, | |
43 | struct lib_ring_buffer_ctx *ctx, | |
a90917c3 | 44 | struct lttng_channel *chan) |
9e7e4892 MD |
45 | { |
46 | pid_t pid; | |
47 | ||
b64bc438 | 48 | pid = task_tgid_nr(current); |
a90917c3 | 49 | lib_ring_buffer_align_ctx(ctx, lttng_alignof(pid)); |
9e7e4892 MD |
50 | chan->ops->event_write(ctx, &pid, sizeof(pid)); |
51 | } | |
52 | ||
53 | int lttng_add_pid_to_ctx(struct lttng_ctx **ctx) | |
54 | { | |
55 | struct lttng_ctx_field *field; | |
9e7e4892 MD |
56 | |
57 | field = lttng_append_context(ctx); | |
58 | if (!field) | |
09fec6b4 | 59 | return -ENOMEM; |
44252f0f MD |
60 | if (lttng_find_context(*ctx, "pid")) { |
61 | lttng_remove_context_field(ctx, field); | |
62 | return -EEXIST; | |
63 | } | |
8070f5c0 MD |
64 | field->event_field.name = "pid"; |
65 | field->event_field.type.atype = atype_integer; | |
66 | field->event_field.type.u.basic.integer.size = sizeof(pid_t) * CHAR_BIT; | |
a90917c3 | 67 | field->event_field.type.u.basic.integer.alignment = lttng_alignof(pid_t) * CHAR_BIT; |
8070f5c0 MD |
68 | field->event_field.type.u.basic.integer.signedness = is_signed_type(pid_t); |
69 | field->event_field.type.u.basic.integer.reverse_byte_order = 0; | |
70 | field->event_field.type.u.basic.integer.base = 10; | |
71 | field->event_field.type.u.basic.integer.encoding = lttng_encode_none; | |
f1676205 MD |
72 | field->get_size = pid_get_size; |
73 | field->record = pid_record; | |
9e7e4892 MD |
74 | wrapper_vmalloc_sync_all(); |
75 | return 0; | |
76 | } | |
8070f5c0 | 77 | EXPORT_SYMBOL_GPL(lttng_add_pid_to_ctx); |
9e7e4892 MD |
78 | |
79 | MODULE_LICENSE("GPL and additional rights"); | |
80 | MODULE_AUTHOR("Mathieu Desnoyers"); | |
53f1f0ca | 81 | MODULE_DESCRIPTION("Linux Trace Toolkit PID Context"); |