commit 1e487177f1a0e0dae95e4ace22e7c42da0724933
author Maciej Żenczykowski <maze@google.com> Thu Sep 05 09:27:35 2024 -0700
committer Maciej Żenczykowski <maze@google.com> Thu Sep 05 09:32:39 2024 -0700
tree 97b67b5da92ebf3459770e702b4cafdd5cc403c7
parent 3e213ffa46f40e9679d381c0ae3bd5e297b4968c

NetBpfLoad: support bpf.o without program section

Test: TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I7320cf60a8994a6c8da99293f068265f54a9ddc6

bpf/loader/NetBpfLoad.cpp

diff --git a/bpf/loader/NetBpfLoad.cpp b/bpf/loader/NetBpfLoad.cpp
index 4767dfa..31f40d6 100644
--- a/bpf/loader/NetBpfLoad.cpp
+++ b/bpf/loader/NetBpfLoad.cpp
@@ -1144,12 +1144,6 @@
     ALOGD("BpfLoader version 0x%05x processing ELF object %s with ver [0x%05x,0x%05x)",
           bpfloader_ver, elfPath, bpfLoaderMinVer, bpfLoaderMaxVer);
 
-    ret = readCodeSections(elfFile, cs);
-    if (ret) {
-        ALOGE("Couldn't read all code sections in %s", elfPath);
-        return ret;
-    }
-
     ret = createMaps(elfPath, elfFile, mapFds, prefix, bpfloader_ver);
     if (ret) {
         ALOGE("Failed to create maps: (ret=%d) in %s", ret, elfPath);
@@ -1159,6 +1153,13 @@
     for (int i = 0; i < (int)mapFds.size(); i++)
         ALOGV("map_fd found at %d is %d in %s", i, mapFds[i].get(), elfPath);
 
+    ret = readCodeSections(elfFile, cs);
+    if (ret == -ENOENT) return 0;  // no programs defined in this .o
+    if (ret) {
+        ALOGE("Couldn't read all code sections in %s", elfPath);
+        return ret;
+    }
+
     applyMapRelo(elfFile, mapFds, cs);
 
     ret = loadCodeSections(elfPath, cs, string(license.data()), prefix, bpfloader_ver);