projects / lttng-modules.git / blame
| Commit | Line | Data |
|---|---|---|
| b64bc438 MD |
1 | /* |
| 2 | * (C) Copyright 2009-2011 - | |
| 3 | * Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
| 4 | * | |
| 5 | * LTTng vPPID context. | |
| 6 | * | |
| 7 | * Dual LGPL v2.1/GPL v2 license. | |
| 8 | */ | |
| 9 | ||
| 10 | #include <linux/module.h> | |
| 11 | #include <linux/slab.h> | |
| 12 | #include <linux/sched.h> | |
| 13 | #include <linux/syscalls.h> | |
| 14 | #include "ltt-events.h" | |
| 15 | #include "wrapper/ringbuffer/frontend_types.h" | |
| 16 | #include "wrapper/vmalloc.h" | |
| 17 | #include "ltt-tracer.h" | |
| 18 | ||
| 19 | static | |
| 20 | size_t vppid_get_size(size_t offset) | |
| 21 | { | |
| 22 | size_t size = 0; | |
| 23 | ||
| 24 | size += lib_ring_buffer_align(offset, ltt_alignof(pid_t)); | |
| 25 | size += sizeof(pid_t); | |
| 26 | return size; | |
| 27 | } | |
| 28 | ||
| 29 | static | |
| 30 | void vppid_record(struct lttng_ctx_field *field, | |
| 31 | struct lib_ring_buffer_ctx *ctx, | |
| 32 | struct ltt_channel *chan) | |
| 33 | { | |
| 90f96adf | 34 | struct task_struct *parent; |
| b64bc438 MD |
35 | pid_t vppid; |
| 36 | ||
| 90f96adf MD |
37 | /* |
| 38 | * nsproxy can be NULL when scheduled out of exit. | |
| 39 | */ | |
| b64bc438 | 40 | rcu_read_lock(); |
| 90f96adf MD |
41 | parent = rcu_dereference(current->real_parent); |
| 42 | if (!parent->nsproxy) | |
| 43 | vppid = 0; | |
| 44 | else | |
| 45 | vppid = task_tgid_vnr(parent); | |
| b64bc438 MD |
46 | rcu_read_unlock(); |
| 47 | lib_ring_buffer_align_ctx(ctx, ltt_alignof(vppid)); | |
| 48 | chan->ops->event_write(ctx, &vppid, sizeof(vppid)); | |
| 49 | } | |
| 50 | ||
| 51 | int lttng_add_vppid_to_ctx(struct lttng_ctx **ctx) | |
| 52 | { | |
| 53 | struct lttng_ctx_field *field; | |
| b64bc438 MD |
54 | |
| 55 | field = lttng_append_context(ctx); | |
| 56 | if (!field) | |
| 09fec6b4 | 57 | return -ENOMEM; |
| 44252f0f MD |
58 | if (lttng_find_context(*ctx, "vppid")) { |
| 59 | lttng_remove_context_field(ctx, field); | |
| 60 | return -EEXIST; | |
| 61 | } | |
| b64bc438 MD |
62 | field->event_field.name = "vppid"; |
| 63 | field->event_field.type.atype = atype_integer; | |
| 64 | field->event_field.type.u.basic.integer.size = sizeof(pid_t) * CHAR_BIT; | |
| 65 | field->event_field.type.u.basic.integer.alignment = ltt_alignof(pid_t) * CHAR_BIT; | |
| 66 | field->event_field.type.u.basic.integer.signedness = is_signed_type(pid_t); | |
| 67 | field->event_field.type.u.basic.integer.reverse_byte_order = 0; | |
| 68 | field->event_field.type.u.basic.integer.base = 10; | |
| 69 | field->event_field.type.u.basic.integer.encoding = lttng_encode_none; | |
| 70 | field->get_size = vppid_get_size; | |
| 71 | field->record = vppid_record; | |
| 72 | wrapper_vmalloc_sync_all(); | |
| 73 | return 0; | |
| 74 | } | |
| 75 | EXPORT_SYMBOL_GPL(lttng_add_vppid_to_ctx); | |
| 76 | ||
| 77 | MODULE_LICENSE("GPL and additional rights"); | |
| 78 | MODULE_AUTHOR("Mathieu Desnoyers"); | |
| 79 | MODULE_DESCRIPTION("Linux Trace Toolkit vPPID Context"); |