Merge "detect inability to write to index != 0 of bpf map array" am: 515bf77a8a

Original change: https://android-review.googlesource.com/c/platform/system/bpf/+/2168142

Change-Id: I8a42f7b60e5939637d1e3aee4054e2124fc196e2
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
diff --git a/bpfloader/BpfLoader.cpp b/bpfloader/BpfLoader.cpp
index f0ff413..fd261b5 100644
--- a/bpfloader/BpfLoader.cpp
+++ b/bpfloader/BpfLoader.cpp
@@ -275,6 +275,15 @@
         }
     }
 
+    int key = 1;
+    int value = 123;
+    android::base::unique_fd map(
+            android::bpf::createMap(BPF_MAP_TYPE_ARRAY, sizeof(key), sizeof(value), 2, 0));
+    if (android::bpf::writeToMapEntry(map, &key, &value, BPF_ANY)) {
+        ALOGE("Critical kernel bug - failure to write into index 1 of 2 element bpf map array.");
+        return 1;
+    }
+
     if (android::base::SetProperty("bpf.progs_loaded", "1") == false) {
         ALOGE("Failed to set bpf.progs_loaded property");
         return 1;