upload android base code part3

android/bionic/linker/linker_namespaces.cpp

@@ -0,0 +1,128 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "linker_namespaces.h"
+#include "linker_globals.h"
+#include "linker_soinfo.h"
+#include "linker_utils.h"
+
+#include <dlfcn.h>
+
+bool android_namespace_t::is_accessible(const std::string& file) {
+  if (!is_isolated_) {
+    return true;
+  }
+
+  for (const auto& dir : ld_library_paths_) {
+    if (file_is_in_dir(file, dir)) {
+      return true;
+    }
+  }
+
+  for (const auto& dir : default_library_paths_) {
+    if (file_is_in_dir(file, dir)) {
+      return true;
+    }
+  }
+
+  for (const auto& dir : permitted_paths_) {
+    if (file_is_under_dir(file, dir)) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+bool android_namespace_t::is_accessible(soinfo* s) {
+  auto is_accessible_ftor = [this] (soinfo* si) {
+    // This is workaround for apps hacking into soinfo list.
+    // and inserting their own entries into it. (http://b/37191433)
+    if (!si->has_min_version(3)) {
+      DL_WARN("invalid soinfo version for \"%s\"", si->get_soname());
+      return false;
+    }
+
+    if (si->get_primary_namespace() == this) {
+      return true;
+    }
+
+    const android_namespace_list_t& secondary_namespaces = si->get_secondary_namespaces();
+    if (secondary_namespaces.find(this) != secondary_namespaces.end()) {
+      return true;
+    }
+
+    return false;
+  };
+
+  if (is_accessible_ftor(s)) {
+    return true;
+  }
+
+  return !s->get_parents().visit([&](soinfo* si) {
+    return !is_accessible_ftor(si);
+  });
+}
+
+// TODO: this is slightly unusual way to construct
+// the global group for relocation. Not every RTLD_GLOBAL
+// library is included in this group for backwards-compatibility
+// reasons.
+//
+// This group consists of the main executable, LD_PRELOADs
+// and libraries with the DF_1_GLOBAL flag set.
+soinfo_list_t android_namespace_t::get_global_group() {
+  soinfo_list_t global_group;
+  soinfo_list().for_each([&](soinfo* si) {
+    if ((si->get_dt_flags_1() & DF_1_GLOBAL) != 0) {
+      global_group.push_back(si);
+    }
+  });
+
+  return global_group;
+}
+
+// This function provides a list of libraries to be shared
+// by the namespace. For the default namespace this is the global
+// group (see get_global_group). For all others this is a group
+// of RTLD_GLOBAL libraries (which includes the global group from
+// the default namespace).
+soinfo_list_t android_namespace_t::get_shared_group() {
+  if (this == &g_default_namespace) {
+    return get_global_group();
+  }
+
+  soinfo_list_t shared_group;
+  soinfo_list().for_each([&](soinfo* si) {
+    if ((si->get_rtld_flags() & RTLD_GLOBAL) != 0) {
+      shared_group.push_back(si);
+    }
+  });
+
+  return shared_group;
+}