From 7fb8b546e3d6476727d79771ede5bd945cd24980 Mon Sep 17 00:00:00 2001
From: Paul Lawrence <paullawrence@google.com>
Date: Tue, 19 Jul 2022 16:13:49 -0700
Subject: [PATCH] Add fuse prog types to allowed prog types from system

Until fuse-bpf is upstreamed, the value BPF_PROG_TYPE_FUSE is
dynamically defined, so use BPF_PROG_TYPE_UNSPEC as a placeholder and read
the actual value from sys/fs/fuse

Bug: 202785178
Test: fuse bpf can be enabled successfully
Change-Id: I67d3ff45768b581a6b239e235edaa6e46a2f6fe0
---
 bpfloader/BpfLoader.cpp   |  1 +
 libbpf_android/Loader.cpp | 17 +++++++++++------
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/bpfloader/BpfLoader.cpp b/bpfloader/BpfLoader.cpp
index b8dd504..f0ff413 100644
--- a/bpfloader/BpfLoader.cpp
+++ b/bpfloader/BpfLoader.cpp
@@ -107,6 +107,7 @@ constexpr bpf_prog_type kPlatformAllowedProgTypes[] = {
         BPF_PROG_TYPE_PERF_EVENT,
         BPF_PROG_TYPE_SOCKET_FILTER,
         BPF_PROG_TYPE_TRACEPOINT,
+        BPF_PROG_TYPE_UNSPEC,  // Will be replaced with fuse bpf program type
 };
 
 // see b/162057235. For arbitrary program types, the concern is that due to the lack of
diff --git a/libbpf_android/Loader.cpp b/libbpf_android/Loader.cpp
index d68f407..ba0ed4c 100644
--- a/libbpf_android/Loader.cpp
+++ b/libbpf_android/Loader.cpp
@@ -354,16 +354,18 @@ static int readSymTab(ifstream& elfFile, int sort, vector<Elf64_Sym>& data) {
     return 0;
 }
 
+static enum bpf_prog_type getFuseProgType() {
+    int result = BPF_PROG_TYPE_UNSPEC;
+    ifstream("/sys/fs/fuse/bpf_prog_type_fuse") >> result;
+    return static_cast<bpf_prog_type>(result);
+}
+
 static enum bpf_prog_type getSectionType(string& name) {
     for (auto& snt : sectionNameTypes)
         if (StartsWith(name, snt.name)) return snt.type;
 
     // TODO Remove this code when fuse-bpf is upstream and this BPF_PROG_TYPE_FUSE is fixed
-    if (StartsWith(name, "fuse/")) {
-        int result = BPF_PROG_TYPE_UNSPEC;
-        ifstream("/sys/fs/fuse/bpf_prog_type_fuse") >> result;
-        return static_cast<bpf_prog_type>(result);
-    }
+    if (StartsWith(name, "fuse/")) return getFuseProgType();
 
     return BPF_PROG_TYPE_UNSPEC;
 }
@@ -465,7 +467,10 @@ static bool IsAllowed(bpf_prog_type type, const bpf_prog_type* allowed, size_t n
     if (allowed == nullptr) return true;
 
     for (size_t i = 0; i < numAllowed; i++) {
-        if (type == allowed[i]) return true;
+        if (allowed[i] == BPF_PROG_TYPE_UNSPEC) {
+            if (type == getFuseProgType()) return true;
+        } else if (type == allowed[i])
+            return true;
     }
 
     return false;