1 /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
3 * lttng-context-migratable.c
5 * LTTng migratable context.
7 * Copyright (C) 2009-2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
10 #include <linux/module.h>
11 #include <linux/slab.h>
12 #include <linux/sched.h>
13 #include <linux/irqflags.h>
14 #include <lttng-events.h>
15 #include <ringbuffer/frontend_types.h>
16 #include <wrapper/vmalloc.h>
17 #include <lttng-tracer.h>
20 size_t migratable_get_size(size_t offset
)
24 size
+= lib_ring_buffer_align(offset
, lttng_alignof(uint8_t));
25 size
+= sizeof(uint8_t);
30 void migratable_record(struct lttng_ctx_field
*field
,
31 struct lib_ring_buffer_ctx
*ctx
,
32 struct lttng_channel
*chan
)
34 uint8_t migratable
= !current
->migrate_disable
;
36 lib_ring_buffer_align_ctx(ctx
, lttng_alignof(migratable
));
37 chan
->ops
->event_write(ctx
, &migratable
, sizeof(migratable
));
41 void migratable_get_value(struct lttng_ctx_field
*field
,
42 struct lttng_probe_ctx
*lttng_probe_ctx
,
43 union lttng_ctx_value
*value
)
45 value
->s64
= !current
->migrate_disable
;
48 int lttng_add_migratable_to_ctx(struct lttng_ctx
**ctx
)
50 struct lttng_ctx_field
*field
;
52 field
= lttng_append_context(ctx
);
55 if (lttng_find_context(*ctx
, "migratable")) {
56 lttng_remove_context_field(ctx
, field
);
59 field
->event_field
.name
= "migratable";
60 field
->event_field
.type
.atype
= atype_integer
;
61 field
->event_field
.type
.u
.integer
.size
= sizeof(uint8_t) * CHAR_BIT
;
62 field
->event_field
.type
.u
.integer
.alignment
= lttng_alignof(uint8_t) * CHAR_BIT
;
63 field
->event_field
.type
.u
.integer
.signedness
= lttng_is_signed_type(uint8_t);
64 field
->event_field
.type
.u
.integer
.reverse_byte_order
= 0;
65 field
->event_field
.type
.u
.integer
.base
= 10;
66 field
->event_field
.type
.u
.integer
.encoding
= lttng_encode_none
;
67 field
->get_size
= migratable_get_size
;
68 field
->record
= migratable_record
;
69 field
->get_value
= migratable_get_value
;
70 lttng_context_update(*ctx
);
71 wrapper_vmalloc_sync_mappings();
74 EXPORT_SYMBOL_GPL(lttng_add_migratable_to_ctx
);