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> | |
2df37e95 | 13 | #include <lttng/events.h> |
437d5aa5 | 14 | #include <lttng/events-internal.h> |
24591303 | 15 | #include <ringbuffer/frontend_types.h> |
241ae9a8 | 16 | #include <wrapper/vmalloc.h> |
2df37e95 | 17 | #include <lttng/tracer.h> |
9e7e4892 | 18 | |
f1676205 | 19 | static |
a92e844e | 20 | size_t pid_get_size(void *priv, struct lttng_kernel_probe_ctx *probe_ctx, size_t offset) |
f1676205 MD |
21 | { |
22 | size_t size = 0; | |
23 | ||
a90917c3 | 24 | size += lib_ring_buffer_align(offset, lttng_alignof(pid_t)); |
f1676205 MD |
25 | size += sizeof(pid_t); |
26 | return size; | |
27 | } | |
28 | ||
9e7e4892 | 29 | static |
a92e844e | 30 | void pid_record(void *priv, struct lttng_kernel_probe_ctx *probe_ctx, |
8a57ec02 | 31 | struct lttng_kernel_ring_buffer_ctx *ctx, |
f7d06400 | 32 | struct lttng_kernel_channel_buffer *chan) |
9e7e4892 MD |
33 | { |
34 | pid_t pid; | |
35 | ||
b64bc438 | 36 | pid = task_tgid_nr(current); |
f5ffbd77 | 37 | chan->ops->event_write(ctx, &pid, sizeof(pid), lttng_alignof(pid)); |
9e7e4892 MD |
38 | } |
39 | ||
f127e61e | 40 | static |
2dc781e0 | 41 | void pid_get_value(void *priv, |
a92e844e | 42 | struct lttng_kernel_probe_ctx *lttng_probe_ctx, |
2dc781e0 | 43 | struct lttng_ctx_value *value) |
f127e61e | 44 | { |
2dc781e0 | 45 | value->u.s64 = task_tgid_nr(current); |
f127e61e MD |
46 | } |
47 | ||
437d5aa5 MD |
48 | static const struct lttng_kernel_ctx_field *ctx_field = lttng_kernel_static_ctx_field( |
49 | lttng_kernel_static_event_field("pid", | |
50 | lttng_kernel_static_type_integer_from_type(pid_t, __BYTE_ORDER, 10), | |
4697aac7 | 51 | false, false), |
437d5aa5 | 52 | pid_get_size, |
437d5aa5 MD |
53 | pid_record, |
54 | pid_get_value, | |
55 | NULL, NULL); | |
56 | ||
57 | int lttng_add_pid_to_ctx(struct lttng_kernel_ctx **ctx) | |
9e7e4892 | 58 | { |
437d5aa5 | 59 | int ret; |
9e7e4892 | 60 | |
437d5aa5 | 61 | if (lttng_kernel_find_context(*ctx, ctx_field->event_field->name)) |
44252f0f | 62 | return -EEXIST; |
437d5aa5 | 63 | ret = lttng_kernel_context_append(ctx, ctx_field); |
263b6c88 | 64 | wrapper_vmalloc_sync_mappings(); |
437d5aa5 | 65 | return ret; |
9e7e4892 | 66 | } |
8070f5c0 | 67 | EXPORT_SYMBOL_GPL(lttng_add_pid_to_ctx); |