init: do not impose vendor_init restrictions on old vendor images

Do not restrict vendor_init restrictions on vendor images that were
built before P, as they will not have the correct permissions.

Bug: 77732028
Test: test new devices and see vendor_init still works
Merged-In: I636a07b54fbfb248e1d1a68a8f3c4d047fd5a9e9
Change-Id: I636a07b54fbfb248e1d1a68a8f3c4d047fd5a9e9
(cherry picked from commit a1dbeb8d338017715ae7747e5a7a3999a54e7213)

3 files changed, 18 insertions, 5 deletions

diff --git a/init/host_init_stubs.h b/init/host_init_stubs.h
index f31ece60c..ddfb7ae7d 100644
--- a/init/host_init_stubs.h
+++ b/init/host_init_stubs.h
@@ -35,6 +35,11 @@ namespace base {
 
 std::string GetProperty(const std::string& key, const std::string& default_value);
 bool GetBoolProperty(const std::string& key, bool default_value);
+template <typename T>
+T GetIntProperty(const std::string&, T default_value, T = std::numeric_limits<T>::min(),
+                 T = std::numeric_limits<T>::max()) {
+    return default_value;
+}
 
 }  // namespace base
 }  // namespace android
diff --git a/init/property_service.cpp b/init/property_service.cpp
index 95ef35c30..99d3c83b1 100644
--- a/init/property_service.cpp
+++ b/init/property_service.cpp
@@ -64,6 +64,7 @@
 
 using namespace std::literals;
 
+using android::base::GetIntProperty;
 using android::base::ReadFileToString;
 using android::base::Split;
 using android::base::StartsWith;
@@ -541,9 +542,11 @@ static void LoadProperties(char* data, const char* filter, const char* filename)
     size_t flen = 0;
 
     const char* context = kInitContext.c_str();
-    for (const auto& [path_prefix, secontext] : paths_and_secontexts) {
-        if (StartsWith(filename, path_prefix)) {
-            context = secontext;
+    if (GetIntProperty("ro.vndk.version", 28) >= 28) {
+        for (const auto& [path_prefix, secontext] : paths_and_secontexts) {
+            if (StartsWith(filename, path_prefix)) {
+                context = secontext;
+            }
         }
     }
 
diff --git a/init/subcontext.cpp b/init/subcontext.cpp
index c1846f76d..9c0c0bb4f 100644
--- a/init/subcontext.cpp
+++ b/init/subcontext.cpp
@@ -30,6 +30,8 @@
 #include "util.h"
 
 #if defined(__ANDROID__)
+#include <android-base/properties.h>
+
 #include "property_service.h"
 #include "selinux.h"
 #else
@@ -37,6 +39,7 @@
 #endif
 
 using android::base::GetExecutablePath;
+using android::base::GetIntProperty;
 using android::base::Join;
 using android::base::Socketpair;
 using android::base::Split;
@@ -354,8 +357,10 @@ Result<std::vector<std::string>> Subcontext::ExpandArgs(const std::vector<std::s
 static std::vector<Subcontext> subcontexts;
 
 std::vector<Subcontext>* InitializeSubcontexts() {
-    for (const auto& [path_prefix, secontext] : paths_and_secontexts) {
-        subcontexts.emplace_back(path_prefix, secontext);
+    if (GetIntProperty("ro.vndk.version", 28) >= 28) {
+        for (const auto& [path_prefix, secontext] : paths_and_secontexts) {
+            subcontexts.emplace_back(path_prefix, secontext);
+        }
     }
     return &subcontexts;
 }