commit b648a8a57ee42533a5bf127225a252f73ca2cbbc
author Dmitriy Ivanov <dimitry@google.com> Mon May 19 15:06:58 2014 -0700
committer Dmitriy Ivanov <dimitry@google.com> Tue May 20 12:02:24 2014 -0700
tree 09fdf06c6e8d5e6985107f4e8fdb2055c5bb6a6f
parent 0b9a72ce1124f17d514b93c0d26dea76ce8069f0

Add RTLD_NOLOAD support and some related changes.

 * Aligned RTLD_ values with glibc for lp64
 * dlopen supports RTLD_NOLOAD flag
 * soinfo_unload calls find_library(.., RTLD_NOLOAD)
   instead of naive find_loaded_library_by_name()
 * dlopen changed to add child to caller soinfo instead
   of somain.

Bug: https://code.google.com/p/android/issues/detail?id=64069
Change-Id: I1a65f2c34f3e0edc6d2c41a2e408b58195feb640

linker/dlfcn.cpp

diff --git a/linker/dlfcn.cpp b/linker/dlfcn.cpp
index 85e91c3..8ef1212 100644
--- a/linker/dlfcn.cpp
+++ b/linker/dlfcn.cpp
@@ -65,10 +65,10 @@
   do_android_update_LD_LIBRARY_PATH(ld_library_path);
 }
 
-void* android_dlopen_ext(const char* filename, int flags, const android_dlextinfo* extinfo)
-{
+static void* dlopen_ext(const char* filename, int flags, const android_dlextinfo* extinfo, const void* caller_addr) {
   ScopedPthreadMutexLocker locker(&g_dl_mutex);
-  soinfo* result = do_dlopen(filename, flags, extinfo);
+  soinfo* caller_soinfo = find_containing_library(caller_addr);
+  soinfo* result = do_dlopen(filename, flags, caller_soinfo, extinfo);
   if (result == NULL) {
     __bionic_format_dlerror("dlopen failed", linker_get_error_buffer());
     return NULL;
@@ -76,8 +76,14 @@
   return result;
 }
 
+void* android_dlopen_ext(const char* filename, int flags, const android_dlextinfo* extinfo) {
+  void* caller_addr = __builtin_return_address(0);
+  return dlopen_ext(filename, flags, extinfo, caller_addr);
+}
+
 void* dlopen(const char* filename, int flags) {
-  return android_dlopen_ext(filename, flags, NULL);
+  void* caller_addr = __builtin_return_address(0);
+  return dlopen_ext(filename, flags, NULL, caller_addr);
 }
 
 void* dlsym(void* handle, const char* symbol) {
@@ -97,8 +103,8 @@
   if (handle == RTLD_DEFAULT) {
     sym = dlsym_linear_lookup(symbol, &found, NULL);
   } else if (handle == RTLD_NEXT) {
-    void* ret_addr = __builtin_return_address(0);
-    soinfo* si = find_containing_library(ret_addr);
+    void* caller_addr = __builtin_return_address(0);
+    soinfo* si = find_containing_library(caller_addr);
 
     sym = NULL;
     if (si && si->next) {
@@ -151,7 +157,9 @@
 
 int dlclose(void* handle) {
   ScopedPthreadMutexLocker locker(&g_dl_mutex);
-  return do_dlclose(reinterpret_cast<soinfo*>(handle));
+  do_dlclose(reinterpret_cast<soinfo*>(handle));
+  // dlclose has no defined errors.
+  return 0;
 }
 
 // name_offset: starting index of the name in libdl_info.strtab