Minimize calls to mprotect
Implement refcounter based data protection guard
to avoid unnecessary calls to mprotect when dlopen/dlclose
is called from a constructor.
Bug: 19124318
Big: 7941716
Change-Id: Id221b84ce75443094f99756dc9950b0a1dc87222
diff --git a/tests/dlfcn_test.cpp b/tests/dlfcn_test.cpp
index 6fdfdc7..3b1001a 100644
--- a/tests/dlfcn_test.cpp
+++ b/tests/dlfcn_test.cpp
@@ -850,3 +850,17 @@
dlclose(handle1);
dlclose(handle2);
}
+
+// libtest_dlopen_from_ctor_main.so depends on
+// libtest_dlopen_from_ctor.so which has a constructor
+// that calls dlopen(libc...). This is to test the situation
+// described in b/7941716.
+TEST(dlfcn, dlopen_dlopen_from_ctor) {
+#if defined(__BIONIC__)
+ void* handle = dlopen("libtest_dlopen_from_ctor_main.so", RTLD_NOW);
+ ASSERT_TRUE(handle != nullptr) << dlerror();
+ dlclose(handle);
+#else
+ GTEST_LOG_(INFO) << "This test is disabled for glibc (glibc segfaults if you try to call dlopen from a constructor).\n";
+#endif
+}
diff --git a/tests/libs/Android.mk b/tests/libs/Android.mk
index 50d96b2..7ca856c 100644
--- a/tests/libs/Android.mk
+++ b/tests/libs/Android.mk
@@ -367,3 +367,29 @@
module := libtest_dlopen_weak_undefined_func
include $(LOCAL_PATH)/Android.build.testlib.mk
+
+# -----------------------------------------------------------------------------
+# Library with constructor that calls dlopen() b/7941716
+# -----------------------------------------------------------------------------
+libtest_dlopen_from_ctor_src_files := \
+ dlopen_testlib_dlopen_from_ctor.cpp
+
+module := libtest_dlopen_from_ctor
+
+build_target := SHARED_LIBRARY
+build_type := host
+include $(TEST_PATH)/Android.build.mk
+
+libtest_dlopen_from_ctor_shared_libraries := libdl
+build_type := target
+include $(TEST_PATH)/Android.build.mk
+
+# -----------------------------------------------------------------------------
+# Library that depends on the library with constructor that calls dlopen() b/7941716
+# -----------------------------------------------------------------------------
+
+libtest_dlopen_from_ctor_main_src_files := empty.cpp
+libtest_dlopen_from_ctor_main_shared_libraries := libtest_dlopen_from_ctor
+
+module := libtest_dlopen_from_ctor_main
+include $(LOCAL_PATH)/Android.build.testlib.mk
diff --git a/tests/libs/dlopen_testlib_dlopen_from_ctor.cpp b/tests/libs/dlopen_testlib_dlopen_from_ctor.cpp
new file mode 100644
index 0000000..95233f7
--- /dev/null
+++ b/tests/libs/dlopen_testlib_dlopen_from_ctor.cpp
@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <dlfcn.h>
+
+static void __attribute__((constructor)) call_dlopen_from_ctor() {
+ void* handle = dlopen("libc.so", RTLD_NOW);
+ dlclose(handle);
+}
+