commit 567dc56b5783073d8721f13acebb3d4bab11aa72
author Maciej Żenczykowski <maze@google.com> Wed Jun 10 15:56:07 2020 -0700
committer Maciej Żenczykowski <maze@google.com> Sat Jun 13 22:41:48 2020 -0700
tree 095745fce47a0aaa8ff9a28c42081c9244d2ed71
parent 00d3a5292c9d7b5618c64b25f50253bdbc9bfbf9

only set 'bpf.progs_loaded' property on eBPF capable devices...

... which also means waitForProgsLoaded() has to be a no-op on pre-bpf devices.

This is more consistent: it's weird to have bpf.progs_loaded set on a 4.4 device.

Test: builds, atest
Bug: 150040815
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: Iddabcf56c187ea518dd2e4d8db451b2f6902aa8e

bpfloader/BpfLoader.cpp

diff --git a/bpfloader/BpfLoader.cpp b/bpfloader/BpfLoader.cpp
index 5390fb4..9e348e5 100644
--- a/bpfloader/BpfLoader.cpp
+++ b/bpfloader/BpfLoader.cpp
@@ -72,10 +72,10 @@
 }
 
 int main() {
-    if (android::bpf::isBpfSupported()) {
-        // Load all ELF objects, create programs and maps, and pin them
-        loadAllElfObjects();
-    }
+    if (!android::bpf::isBpfSupported()) return 0;
+
+    // Load all ELF objects, create programs and maps, and pin them
+    loadAllElfObjects();
 
     if (android::base::SetProperty("bpf.progs_loaded", "1") == false) {
         ALOGE("Failed to set bpf.progs_loaded property\n");

libbpf_android/Loader.cpp

diff --git a/libbpf_android/Loader.cpp b/libbpf_android/Loader.cpp
index f808dc6..4244eb7 100644
--- a/libbpf_android/Loader.cpp
+++ b/libbpf_android/Loader.cpp
@@ -650,6 +650,8 @@
 }
 
 void waitForProgsLoaded() {
+    if (!android::bpf::isBpfSupported()) return;
+
     while (!android::base::WaitForProperty("bpf.progs_loaded", "1", std::chrono::seconds(5))) {
         ALOGW("Waited 5s for bpf.progs_loaded, still waiting...");
     }