Commit | Line | Data |
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b7cdc182 | 1 | /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only) |
9f36eaed | 2 | * |
886d51a3 | 3 | * lttng-context-pid.c |
9e7e4892 MD |
4 | * |
5 | * LTTng PID context. | |
6 | * | |
886d51a3 | 7 | * Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
9e7e4892 MD |
8 | */ |
9 | ||
10 | #include <linux/module.h> | |
11 | #include <linux/slab.h> | |
12 | #include <linux/sched.h> | |
241ae9a8 MD |
13 | #include <lttng-events.h> |
14 | #include <wrapper/ringbuffer/frontend_types.h> | |
241ae9a8 | 15 | #include <lttng-tracer.h> |
9e7e4892 | 16 | |
f1676205 MD |
17 | static |
18 | size_t pid_get_size(size_t offset) | |
19 | { | |
20 | size_t size = 0; | |
21 | ||
a90917c3 | 22 | size += lib_ring_buffer_align(offset, lttng_alignof(pid_t)); |
f1676205 MD |
23 | size += sizeof(pid_t); |
24 | return size; | |
25 | } | |
26 | ||
9e7e4892 MD |
27 | static |
28 | void pid_record(struct lttng_ctx_field *field, | |
29 | struct lib_ring_buffer_ctx *ctx, | |
a90917c3 | 30 | struct lttng_channel *chan) |
9e7e4892 MD |
31 | { |
32 | pid_t pid; | |
33 | ||
b64bc438 | 34 | pid = task_tgid_nr(current); |
a90917c3 | 35 | lib_ring_buffer_align_ctx(ctx, lttng_alignof(pid)); |
9e7e4892 MD |
36 | chan->ops->event_write(ctx, &pid, sizeof(pid)); |
37 | } | |
38 | ||
f127e61e MD |
39 | static |
40 | void pid_get_value(struct lttng_ctx_field *field, | |
79150a49 | 41 | struct lttng_probe_ctx *lttng_probe_ctx, |
f127e61e MD |
42 | union lttng_ctx_value *value) |
43 | { | |
44 | value->s64 = task_tgid_nr(current); | |
45 | } | |
46 | ||
9e7e4892 MD |
47 | int lttng_add_pid_to_ctx(struct lttng_ctx **ctx) |
48 | { | |
49 | struct lttng_ctx_field *field; | |
9e7e4892 MD |
50 | |
51 | field = lttng_append_context(ctx); | |
52 | if (!field) | |
09fec6b4 | 53 | return -ENOMEM; |
44252f0f MD |
54 | if (lttng_find_context(*ctx, "pid")) { |
55 | lttng_remove_context_field(ctx, field); | |
56 | return -EEXIST; | |
57 | } | |
8070f5c0 MD |
58 | field->event_field.name = "pid"; |
59 | field->event_field.type.atype = atype_integer; | |
ceabb767 MD |
60 | field->event_field.type.u.integer.size = sizeof(pid_t) * CHAR_BIT; |
61 | field->event_field.type.u.integer.alignment = lttng_alignof(pid_t) * CHAR_BIT; | |
62 | field->event_field.type.u.integer.signedness = lttng_is_signed_type(pid_t); | |
63 | field->event_field.type.u.integer.reverse_byte_order = 0; | |
64 | field->event_field.type.u.integer.base = 10; | |
65 | field->event_field.type.u.integer.encoding = lttng_encode_none; | |
f1676205 MD |
66 | field->get_size = pid_get_size; |
67 | field->record = pid_record; | |
f127e61e | 68 | field->get_value = pid_get_value; |
a9dd15da | 69 | lttng_context_update(*ctx); |
9e7e4892 MD |
70 | return 0; |
71 | } | |
8070f5c0 | 72 | EXPORT_SYMBOL_GPL(lttng_add_pid_to_ctx); |