Add UMA for testing whether device supports memory mapping APK files with executable permissions.

base/android/linker/linker_jni.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This is the Android-specific Chromium linker, a tiny shared library
 // implementing a custom dynamic linker that can be used to load the
 // real Chromium libraries (e.g. libcontentshell.so).
 
 // The main point of this linker is to be able to share the RELRO
 // section of libcontentshell.so (or equivalent) between the browser and
@@ skipping 556 matching lines @@
       mmap(NULL, bytes, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
   if (address == MAP_FAILED) {
     LOG_INFO("%s: Random base load address not determinable\n", __FUNCTION__);
     return 0;
   }
   munmap(address, bytes);
   LOG_INFO("%s: Random base load address is %p\n", __FUNCTION__, address);
   return static_cast<jlong>(reinterpret_cast<uintptr_t>(address));
 }
 
+// Test whether the device supports memory mapping APK files with executable
+// permissions.
+//
+// |env| is the current JNI environment handle and is ignored here.
+// |clazz| is the static class handle for org.chromium.base.Linker,
+// and is ignored here.
+// |apkfile_name| is the filename of the APK.
+// Returns true if supported.
+jboolean TestLoadFromApk(JNIEnv* env, jclass clazz, jstring apkfile_name) {
+  String apkfile_name_str(env, apkfile_name);
+  return crazy_linker_test_load_from_apk(apkfile_name_str.c_str());
+}
+
 const JNINativeMethod kNativeMethods[] = {
     {"nativeLoadLibrary",
      "("
      "Ljava/lang/String;"
      "J"
      "Lorg/chromium/base/library_loader/Linker$LibInfo;"
      ")"
      "Z",
      reinterpret_cast<void*>(&LoadLibrary)},
     {"nativeLoadLibraryInZipFile",
@@ skipping 29 matching lines @@
     {"nativeCanUseSharedRelro",
      "("
      ")"
      "Z",
      reinterpret_cast<void*>(&CanUseSharedRelro)},
     {"nativeGetRandomBaseLoadAddress",
      "("
      "J"
      ")"
      "J",
-     reinterpret_cast<void*>(&GetRandomBaseLoadAddress)}, };
+     reinterpret_cast<void*>(&GetRandomBaseLoadAddress)},
+     {"nativeTestLoadFromApk",
+      "("
+      "Ljava/lang/String;"
+      ")"
+      "Z",
+      reinterpret_cast<void*>(&TestLoadFromApk)}, };
 
 }  // namespace
 
 // JNI_OnLoad() hook called when the linker library is loaded through
 // the regular System.LoadLibrary) API. This shall save the Java VM
 // handle and initialize LibInfo fields.
 jint JNI_OnLoad(JavaVM* vm, void* reserved) {
   LOG_INFO("%s: Entering", __FUNCTION__);
   // Get new JNIEnv
   JNIEnv* env;
@@ skipping 30 matching lines @@
   crazy_context_t* context = GetCrazyContext();
   crazy_context_set_java_vm(context, vm, JNI_VERSION_1_4);
 
   // Register the function that the crazy linker can call to post code
   // for later execution.
   crazy_context_set_callback_poster(context, &PostForLaterExecution, NULL);
 
   LOG_INFO("%s: Done", __FUNCTION__);
   return JNI_VERSION_1_4;
 }