projects / lttng-modules.git / blame
| Commit | Line | Data |
|---|---|---|
| b64bc438 | 1 | /* |
| 886d51a3 | 2 | * lttng-context-vppid.c |
| b64bc438 MD |
3 | * |
| 4 | * LTTng vPPID 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 vppid_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 vppid_record(struct lttng_ctx_field *field, | |
| 44 | struct lib_ring_buffer_ctx *ctx, | |
| a90917c3 | 45 | struct lttng_channel *chan) |
| b64bc438 | 46 | { |
| 90f96adf | 47 | struct task_struct *parent; |
| b64bc438 MD |
48 | pid_t vppid; |
| 49 | ||
| 90f96adf MD |
50 | /* |
| 51 | * nsproxy can be NULL when scheduled out of exit. | |
| 52 | */ | |
| b64bc438 | 53 | rcu_read_lock(); |
| 90f96adf MD |
54 | parent = rcu_dereference(current->real_parent); |
| 55 | if (!parent->nsproxy) | |
| 56 | vppid = 0; | |
| 57 | else | |
| 58 | vppid = task_tgid_vnr(parent); | |
| b64bc438 | 59 | rcu_read_unlock(); |
| a90917c3 | 60 | lib_ring_buffer_align_ctx(ctx, lttng_alignof(vppid)); |
| b64bc438 MD |
61 | chan->ops->event_write(ctx, &vppid, sizeof(vppid)); |
| 62 | } | |
| 63 | ||
| 64 | int lttng_add_vppid_to_ctx(struct lttng_ctx **ctx) | |
| 65 | { | |
| 66 | struct lttng_ctx_field *field; | |
| b64bc438 MD |
67 | |
| 68 | field = lttng_append_context(ctx); | |
| 69 | if (!field) | |
| 09fec6b4 | 70 | return -ENOMEM; |
| 44252f0f MD |
71 | if (lttng_find_context(*ctx, "vppid")) { |
| 72 | lttng_remove_context_field(ctx, field); | |
| 73 | return -EEXIST; | |
| 74 | } | |
| b64bc438 MD |
75 | field->event_field.name = "vppid"; |
| 76 | field->event_field.type.atype = atype_integer; | |
| 77 | field->event_field.type.u.basic.integer.size = sizeof(pid_t) * CHAR_BIT; | |
| a90917c3 | 78 | field->event_field.type.u.basic.integer.alignment = lttng_alignof(pid_t) * CHAR_BIT; |
| b64bc438 MD |
79 | field->event_field.type.u.basic.integer.signedness = is_signed_type(pid_t); |
| 80 | field->event_field.type.u.basic.integer.reverse_byte_order = 0; | |
| 81 | field->event_field.type.u.basic.integer.base = 10; | |
| 82 | field->event_field.type.u.basic.integer.encoding = lttng_encode_none; | |
| 83 | field->get_size = vppid_get_size; | |
| 84 | field->record = vppid_record; | |
| 85 | wrapper_vmalloc_sync_all(); | |
| 86 | return 0; | |
| 87 | } | |
| 88 | EXPORT_SYMBOL_GPL(lttng_add_vppid_to_ctx); | |
| 89 | ||
| 90 | MODULE_LICENSE("GPL and additional rights"); | |
| 91 | MODULE_AUTHOR("Mathieu Desnoyers"); | |
| 92 | MODULE_DESCRIPTION("Linux Trace Toolkit vPPID Context"); |