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 PPID 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> | |
| a90917c3 | 14 | #include "lttng-events.h" |
| b64bc438 MD |
15 | #include "wrapper/ringbuffer/frontend_types.h" |
| 16 | #include "wrapper/vmalloc.h" | |
| a90917c3 | 17 | #include "lttng-tracer.h" |
| b64bc438 MD |
18 | |
| 19 | static | |
| 20 | size_t ppid_get_size(size_t offset) | |
| 21 | { | |
| 22 | size_t size = 0; | |
| 23 | ||
| a90917c3 | 24 | size += lib_ring_buffer_align(offset, lttng_alignof(pid_t)); |
| b64bc438 MD |
25 | size += sizeof(pid_t); |
| 26 | return size; | |
| 27 | } | |
| 28 | ||
| 29 | static | |
| 30 | void ppid_record(struct lttng_ctx_field *field, | |
| 31 | struct lib_ring_buffer_ctx *ctx, | |
| a90917c3 | 32 | struct lttng_channel *chan) |
| b64bc438 MD |
33 | { |
| 34 | pid_t ppid; | |
| 35 | ||
| 36 | rcu_read_lock(); | |
| 37 | ppid = task_tgid_nr(current->real_parent); | |
| 38 | rcu_read_unlock(); | |
| a90917c3 | 39 | lib_ring_buffer_align_ctx(ctx, lttng_alignof(ppid)); |
| b64bc438 MD |
40 | chan->ops->event_write(ctx, &ppid, sizeof(ppid)); |
| 41 | } | |
| 42 | ||
| 43 | int lttng_add_ppid_to_ctx(struct lttng_ctx **ctx) | |
| 44 | { | |
| 45 | struct lttng_ctx_field *field; | |
| b64bc438 MD |
46 | |
| 47 | field = lttng_append_context(ctx); | |
| 48 | if (!field) | |
| 09fec6b4 | 49 | return -ENOMEM; |
| 44252f0f MD |
50 | if (lttng_find_context(*ctx, "ppid")) { |
| 51 | lttng_remove_context_field(ctx, field); | |
| 52 | return -EEXIST; | |
| 53 | } | |
| b64bc438 MD |
54 | field->event_field.name = "ppid"; |
| 55 | field->event_field.type.atype = atype_integer; | |
| 56 | field->event_field.type.u.basic.integer.size = sizeof(pid_t) * CHAR_BIT; | |
| a90917c3 | 57 | field->event_field.type.u.basic.integer.alignment = lttng_alignof(pid_t) * CHAR_BIT; |
| b64bc438 MD |
58 | field->event_field.type.u.basic.integer.signedness = is_signed_type(pid_t); |
| 59 | field->event_field.type.u.basic.integer.reverse_byte_order = 0; | |
| 60 | field->event_field.type.u.basic.integer.base = 10; | |
| 61 | field->event_field.type.u.basic.integer.encoding = lttng_encode_none; | |
| 62 | field->get_size = ppid_get_size; | |
| 63 | field->record = ppid_record; | |
| 64 | wrapper_vmalloc_sync_all(); | |
| 65 | return 0; | |
| 66 | } | |
| 67 | EXPORT_SYMBOL_GPL(lttng_add_ppid_to_ctx); | |
| 68 | ||
| 69 | MODULE_LICENSE("GPL and additional rights"); | |
| 70 | MODULE_AUTHOR("Mathieu Desnoyers"); | |
| 71 | MODULE_DESCRIPTION("Linux Trace Toolkit PPID Context"); |