X-Git-Url: https://git.liburcu.org/?a=blobdiff_plain;f=src%2Flttng-context-migratable.c;fp=src%2Flttng-context-migratable.c;h=207e02ffd8bee82b3ea5178718b358e58fe62119;hb=cfa6cc1d0f01c2cfcc1a679abf3a6572d411c309;hp=0000000000000000000000000000000000000000;hpb=cd4486798c2b046ea93b89439cd705e93c40b349;p=lttng-modules.git

diff --git a/src/lttng-context-migratable.c b/src/lttng-context-migratable.c
new file mode 100644
index 00000000..207e02ff
--- /dev/null
+++ b/src/lttng-context-migratable.c
@@ -0,0 +1,74 @@
+/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
+ *
+ * lttng-context-migratable.c
+ *
+ * LTTng migratable context.
+ *
+ * Copyright (C) 2009-2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/irqflags.h>
+#include <lttng/events.h>
+#include <ringbuffer/frontend_types.h>
+#include <wrapper/vmalloc.h>
+#include <lttng/tracer.h>
+
+static
+size_t migratable_get_size(size_t offset)
+{
+	size_t size = 0;
+
+	size += lib_ring_buffer_align(offset, lttng_alignof(uint8_t));
+	size += sizeof(uint8_t);
+	return size;
+}
+
+static
+void migratable_record(struct lttng_ctx_field *field,
+		struct lib_ring_buffer_ctx *ctx,
+		struct lttng_channel *chan)
+{
+	uint8_t migratable = !current->migrate_disable;
+
+	lib_ring_buffer_align_ctx(ctx, lttng_alignof(migratable));
+	chan->ops->event_write(ctx, &migratable, sizeof(migratable));
+}
+
+static
+void migratable_get_value(struct lttng_ctx_field *field,
+		struct lttng_probe_ctx *lttng_probe_ctx,
+		union lttng_ctx_value *value)
+{
+	value->s64 = !current->migrate_disable;
+}
+
+int lttng_add_migratable_to_ctx(struct lttng_ctx **ctx)
+{
+	struct lttng_ctx_field *field;
+
+	field = lttng_append_context(ctx);
+	if (!field)
+		return -ENOMEM;
+	if (lttng_find_context(*ctx, "migratable")) {
+		lttng_remove_context_field(ctx, field);
+		return -EEXIST;
+	}
+	field->event_field.name = "migratable";
+	field->event_field.type.atype = atype_integer;
+	field->event_field.type.u.integer.size = sizeof(uint8_t) * CHAR_BIT;
+	field->event_field.type.u.integer.alignment = lttng_alignof(uint8_t) * CHAR_BIT;
+	field->event_field.type.u.integer.signedness = lttng_is_signed_type(uint8_t);
+	field->event_field.type.u.integer.reverse_byte_order = 0;
+	field->event_field.type.u.integer.base = 10;
+	field->event_field.type.u.integer.encoding = lttng_encode_none;
+	field->get_size = migratable_get_size;
+	field->record = migratable_record;
+	field->get_value = migratable_get_value;
+	lttng_context_update(*ctx);
+	wrapper_vmalloc_sync_mappings();
+	return 0;
+}
+EXPORT_SYMBOL_GPL(lttng_add_migratable_to_ctx);