Initial checkin for relocatable ELF loader and link with bcc
* Wrote a relocatable ELF loader from scratch. The loader library loads
all objects in /system/etc/bpf/, parses and fixes up eBPF instructions
based on relocation information, creates maps and programs and pins
them. A single API call without arguments is made which results in this
operation. The API has all the information it needs from the filesystem
and the ELF objects, so there is no configuration stored in the code
calling the loader API essentially making it zero conf. Initially this
will be used by time_in_state statistics collection using tracepoints.
In the future, netd's eBPF C code should be rewritten to use this
infrastructure and the old ELF loader can be gotten rid off. This is the
first step.
* Link libbpf with libbpf_android which will come from the external/ bcc
project. This will be used for tracepoint and perf eBPF support. In the
future it can be used for other things as kernel eBPF support advances.
This patch will be merged only after bcc is cloned into external/ to
prevent build breakage.
Bug: 112334572
Change-Id: Ic0fd9504e18031132d40bb627c5e44058d59c9f8
Signed-off-by: Joel Fernandes <joelaf@google.com>
diff --git a/libbpf_android/include/libbpf_android.h b/libbpf_android/include/libbpf_android.h
new file mode 100644
index 0000000..cea707c
--- /dev/null
+++ b/libbpf_android/include/libbpf_android.h
@@ -0,0 +1,31 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ * Android BPF library - public API
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef LIBBPF_SYSTEM_H
+#define LIBBPF_SYSTEM_H
+
+#include <libbpf.h>
+#include <linux/bpf.h>
+
+namespace android {
+namespace bpf {
+// BPF loader implementation. Loads an eBPF ELF object
+int loadProg(const char* elfpath);
+} // namespace bpf
+} // namespace android
+
+#endif