Merge "Load updated graphics drivers into sphal-child namespace" into oc-dev

#include <log/log.h>

#include <nativeloader/dlext_namespaces.h>

// TODO(b/37049319) Get this from a header once one exists

extern "C" {

  android_namespace_t* android_get_exported_namespace(const char*);

}

namespace android {

/*static*/ GraphicsEnv& GraphicsEnv::getInstance() {

android_namespace_t* GraphicsEnv::getDriverNamespace() {

    static std::once_flag once;

    std::call_once(once, [this]() {

        // TODO; In the next version of Android, all graphics drivers will be

        // loaded into a custom namespace. To minimize risk for this release,

        // only updated drivers use a custom namespace.

        //

        // Additionally, the custom namespace will be

        // ANDROID_NAMESPACE_TYPE_ISOLATED, and will only have access to a

        // subset of the system.

        if (mDriverPath.empty())

            return;

        char defaultPath[PATH_MAX];

        android_get_LD_LIBRARY_PATH(defaultPath, sizeof(defaultPath));

        size_t defaultPathLen = strlen(defaultPath);

        std::string path;

        path.reserve(mDriverPath.size() + 1 + defaultPathLen);

        path.append(mDriverPath);

        path.push_back(':');

        path.append(defaultPath, defaultPathLen);

        mDriverNamespace = android_create_namespace(

                "gfx driver",

        // If the sphal namespace isn't configured for a device, don't support updatable drivers.

        // We need a parent namespace to inherit the default search path from.

        auto sphalNamespace = android_get_exported_namespace("sphal");

        if (!sphalNamespace) return;

        mDriverNamespace = android_create_namespace("gfx driver",

                                                    nullptr,             // ld_library_path

                path.c_str(),               // default_library_path

                ANDROID_NAMESPACE_TYPE_SHARED,

                                                    mDriverPath.c_str(), // default_library_path

                                                    ANDROID_NAMESPACE_TYPE_SHARED |

                                                            ANDROID_NAMESPACE_TYPE_ISOLATED,

                                                    nullptr, // permitted_when_isolated_path

                nullptr);                   // parent

                                                    sphalNamespace);

    });

    return mDriverNamespace;

}