X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=lttng-context-vsgid.c;fp=lttng-context-vsgid.c;h=aca5eda04ef6686d5b94e3506f6b04ec3bc1a7a4;hb=dc923e75c174ee4e7a80e5f9af1dfd39fb8346ea;hp=0000000000000000000000000000000000000000;hpb=a6cf40a4491954d6f81052f8bbce757f73727f16;p=lttng-modules.git

diff --git a/lttng-context-vsgid.c b/lttng-context-vsgid.c
new file mode 100644
index 00000000..aca5eda0
--- /dev/null
+++ b/lttng-context-vsgid.c
@@ -0,0 +1,76 @@
+/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
+ *
+ * lttng-context-vsgid.c
+ *
+ * LTTng namespaced saved set-group-ID context.
+ *
+ * Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *               2019 Michael Jeanson <mjeanson@efficios.com>
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <lttng-events.h>
+#include <lttng-tracer.h>
+#include <wrapper/ringbuffer/frontend_types.h>
+#include <wrapper/vmalloc.h>
+#include <wrapper/user_namespace.h>
+
+static
+size_t vsgid_get_size(size_t offset)
+{
+	size_t size = 0;
+
+	size += lib_ring_buffer_align(offset, lttng_alignof(gid_t));
+	size += sizeof(gid_t);
+	return size;
+}
+
+static
+void vsgid_record(struct lttng_ctx_field *field,
+		 struct lib_ring_buffer_ctx *ctx,
+		 struct lttng_channel *chan)
+{
+	gid_t vsgid;
+
+	vsgid = lttng_current_vsgid();
+	lib_ring_buffer_align_ctx(ctx, lttng_alignof(vsgid));
+	chan->ops->event_write(ctx, &vsgid, sizeof(vsgid));
+}
+
+static
+void vsgid_get_value(struct lttng_ctx_field *field,
+		struct lttng_probe_ctx *lttng_probe_ctx,
+		union lttng_ctx_value *value)
+{
+	value->s64 = lttng_current_vsgid();
+}
+
+int lttng_add_vsgid_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, "vsgid")) {
+		lttng_remove_context_field(ctx, field);
+		return -EEXIST;
+	}
+	field->event_field.name = "vsgid";
+	field->event_field.type.atype = atype_integer;
+	field->event_field.type.u.basic.integer.size = sizeof(gid_t) * CHAR_BIT;
+	field->event_field.type.u.basic.integer.alignment = lttng_alignof(gid_t) * CHAR_BIT;
+	field->event_field.type.u.basic.integer.signedness = lttng_is_signed_type(gid_t);
+	field->event_field.type.u.basic.integer.reverse_byte_order = 0;
+	field->event_field.type.u.basic.integer.base = 10;
+	field->event_field.type.u.basic.integer.encoding = lttng_encode_none;
+	field->get_size = vsgid_get_size;
+	field->record = vsgid_record;
+	field->get_value = vsgid_get_value;
+	lttng_context_update(*ctx);
+	wrapper_vmalloc_sync_all();
+	return 0;
+}
+EXPORT_SYMBOL_GPL(lttng_add_vsgid_to_ctx);