Cleanup: Move all source files to src/
[lttng-modules.git] / src / lttng-context-vpid.c
diff --git a/src/lttng-context-vpid.c b/src/lttng-context-vpid.c
new file mode 100644 (file)
index 0000000..28178b9
--- /dev/null
@@ -0,0 +1,89 @@
+/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
+ *
+ * lttng-context-vpid.c
+ *
+ * LTTng vPID context.
+ *
+ * Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <lttng/events.h>
+#include <ringbuffer/frontend_types.h>
+#include <wrapper/vmalloc.h>
+#include <lttng/tracer.h>
+
+static
+size_t vpid_get_size(size_t offset)
+{
+       size_t size = 0;
+
+       size += lib_ring_buffer_align(offset, lttng_alignof(pid_t));
+       size += sizeof(pid_t);
+       return size;
+}
+
+static
+void vpid_record(struct lttng_ctx_field *field,
+                struct lib_ring_buffer_ctx *ctx,
+                struct lttng_channel *chan)
+{
+       pid_t vpid;
+
+       /*
+        * nsproxy can be NULL when scheduled out of exit.
+        */
+       if (!current->nsproxy)
+               vpid = 0;
+       else
+               vpid = task_tgid_vnr(current);
+       lib_ring_buffer_align_ctx(ctx, lttng_alignof(vpid));
+       chan->ops->event_write(ctx, &vpid, sizeof(vpid));
+}
+
+static
+void vpid_get_value(struct lttng_ctx_field *field,
+               struct lttng_probe_ctx *lttng_probe_ctx,
+               union lttng_ctx_value *value)
+{
+       pid_t vpid;
+
+       /*
+        * nsproxy can be NULL when scheduled out of exit.
+        */
+       if (!current->nsproxy)
+               vpid = 0;
+       else
+               vpid = task_tgid_vnr(current);
+       value->s64 = vpid;
+}
+
+int lttng_add_vpid_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, "vpid")) {
+               lttng_remove_context_field(ctx, field);
+               return -EEXIST;
+       }
+       field->event_field.name = "vpid";
+       field->event_field.type.atype = atype_integer;
+       field->event_field.type.u.integer.size = sizeof(pid_t) * CHAR_BIT;
+       field->event_field.type.u.integer.alignment = lttng_alignof(pid_t) * CHAR_BIT;
+       field->event_field.type.u.integer.signedness = lttng_is_signed_type(pid_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 = vpid_get_size;
+       field->record = vpid_record;
+       field->get_value = vpid_get_value;
+       lttng_context_update(*ctx);
+       wrapper_vmalloc_sync_mappings();
+       return 0;
+}
+EXPORT_SYMBOL_GPL(lttng_add_vpid_to_ctx);
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