Make android_load_sphal_library thread-safe
Also: remove an obsolete comment from linker_test.cpp. The test program is
at /data/nativetest[64]/libvndksupport-tests/libvndksupport-tests, which
may will be in the system or legacy configuration, and either the "sphal"
or "default" namespace will be visible.
Bug: none
Test: run libvndksupport-tests, device boots
Change-Id: I5e33e5bf1402a0368e046b03827c216789b02c96
diff --git a/libvndksupport/linker.cpp b/libvndksupport/linker.cpp
index 057e5b1..cf0f618 100644
--- a/libvndksupport/linker.cpp
+++ b/libvndksupport/linker.cpp
@@ -13,40 +13,44 @@
* See the License for the specific language governing permissions and
* limitations under the License.
*/
+
+#define LOG_TAG "vndksupport"
+
#include "linker.h"
#include <android/dlext.h>
#include <dlfcn.h>
-
-#define LOG_TAG "vndksupport"
#include <log/log.h>
#include <sys/types.h>
#include <unistd.h>
-__attribute__((weak)) extern "C" struct android_namespace_t* android_get_exported_namespace(
- const char*);
+#include <initializer_list>
+
+__attribute__((weak)) extern "C" android_namespace_t* android_get_exported_namespace(const char*);
__attribute__((weak)) extern "C" void* android_dlopen_ext(const char*, int,
const android_dlextinfo*);
-static const char* namespace_name = NULL;
+namespace {
-static struct android_namespace_t* get_vendor_namespace() {
- const char* namespace_names[] = {"sphal", "default", NULL};
- static struct android_namespace_t* vendor_namespace = NULL;
- if (vendor_namespace == NULL) {
- int name_idx = 0;
- while (namespace_names[name_idx] != NULL) {
- if (android_get_exported_namespace != NULL) {
- vendor_namespace = android_get_exported_namespace(namespace_names[name_idx]);
+struct VendorNamespace {
+ android_namespace_t* ptr = nullptr;
+ const char* name = nullptr;
+};
+
+} // anonymous namespace
+
+static VendorNamespace get_vendor_namespace() {
+ static VendorNamespace result = ([] {
+ for (const char* name : {"sphal", "default"}) {
+ if (android_get_exported_namespace != nullptr) {
+ if (android_namespace_t* ns = android_get_exported_namespace(name)) {
+ return VendorNamespace{ns, name};
+ }
}
- if (vendor_namespace != NULL) {
- namespace_name = namespace_names[name_idx];
- break;
- }
- name_idx++;
}
- }
- return vendor_namespace;
+ return VendorNamespace{};
+ })();
+ return result;
}
int android_is_in_vendor_process() {
@@ -55,29 +59,30 @@
if (getpid() == 1) {
return 0;
}
- if (android_get_exported_namespace == NULL) {
+ if (android_get_exported_namespace == nullptr) {
ALOGD("android_get_exported_namespace() not available. Assuming system process.");
return 0;
}
// In vendor process, 'vndk' namespace is not visible, whereas in system
// process, it is.
- return android_get_exported_namespace("vndk") == NULL;
+ return android_get_exported_namespace("vndk") == nullptr;
}
void* android_load_sphal_library(const char* name, int flag) {
- struct android_namespace_t* vendor_namespace = get_vendor_namespace();
- if (vendor_namespace != NULL) {
+ VendorNamespace vendor_namespace = get_vendor_namespace();
+ if (vendor_namespace.ptr != nullptr) {
const android_dlextinfo dlextinfo = {
.flags = ANDROID_DLEXT_USE_NAMESPACE,
- .library_namespace = vendor_namespace,
+ .library_namespace = vendor_namespace.ptr,
};
- void* handle = NULL;
- if (android_dlopen_ext != NULL) {
+ void* handle = nullptr;
+ if (android_dlopen_ext != nullptr) {
handle = android_dlopen_ext(name, flag, &dlextinfo);
}
if (!handle) {
- ALOGE("Could not load %s from %s namespace: %s.", name, namespace_name, dlerror());
+ ALOGE("Could not load %s from %s namespace: %s.", name, vendor_namespace.name,
+ dlerror());
}
return handle;
} else {
diff --git a/libvndksupport/tests/linker_test.cpp b/libvndksupport/tests/linker_test.cpp
index 7ce27d4..d0c8ef7 100644
--- a/libvndksupport/tests/linker_test.cpp
+++ b/libvndksupport/tests/linker_test.cpp
@@ -21,11 +21,6 @@
#include <vndksupport/linker.h>
#include <string>
-// Since the test executable will be in /data and ld.config.txt does not
-// configure sphal namespace for executables in /data, the call to
-// android_load_sphal_library will always fallback to the plain dlopen from the
-// default namespace.
-
// Let's use libEGL_<chipset>.so as a SP-HAL in test
static std::string find_sphal_lib() {
const char* path =