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 <lttng/events-internal.h>
16 #include <ringbuffer/frontend_types.h>
17 #include <wrapper/vmalloc.h>
18 #include <lttng/tracer.h>
21 size_t migratable_get_size(void *priv
, struct lttng_kernel_probe_ctx
*probe_ctx
, size_t offset
)
25 size
+= lib_ring_buffer_align(offset
, lttng_alignof(uint8_t));
26 size
+= sizeof(uint8_t);
31 void migratable_record(void *priv
, struct lttng_kernel_probe_ctx
*probe_ctx
,
32 struct lttng_kernel_ring_buffer_ctx
*ctx
,
33 struct lttng_channel
*chan
)
35 uint8_t migratable
= !current
->migrate_disable
;
37 lib_ring_buffer_align_ctx(ctx
, lttng_alignof(migratable
));
38 chan
->ops
->event_write(ctx
, &migratable
, sizeof(migratable
));
42 void migratable_get_value(void *priv
,
43 struct lttng_kernel_probe_ctx
*lttng_probe_ctx
,
44 struct lttng_ctx_value
*value
)
46 value
->u
.s64
= !current
->migrate_disable
;
49 static const struct lttng_kernel_ctx_field
*ctx_field
= lttng_kernel_static_ctx_field(
50 lttng_kernel_static_event_field("migratable",
51 lttng_kernel_static_type_integer_from_type(uint8_t, __BYTE_ORDER
, 10),
58 int lttng_add_migratable_to_ctx(struct lttng_kernel_ctx
**ctx
)
62 if (lttng_kernel_find_context(*ctx
, ctx_field
->event_field
->name
))
64 ret
= lttng_kernel_context_append(ctx
, ctx_field
);
65 wrapper_vmalloc_sync_mappings();
68 EXPORT_SYMBOL_GPL(lttng_add_migratable_to_ctx
);