Fix greylist exception to account for linked namespaces
Do not load second copy of libraries that are supposed to
be provided by linked namespaces. Also do not print
error in the log if caller tries to open shared library
using absolute path for apps targeting N+.
Bug: http://b/35454141
Bug: http://b/26833548
Bug: http://b/35338922
Test: run bionic-unit-tests --gtest_filter=dl*
Change-Id: Icf3aeedff18d287d2ba0b3df3808b100f3ef5f7a
diff --git a/linker/linker.cpp b/linker/linker.cpp
index 136c2b6..a3d1db2 100644
--- a/linker/linker.cpp
+++ b/linker/linker.cpp
@@ -132,9 +132,34 @@
return S_ISREG(s.st_mode);
}
+static std::string resolve_soname(const std::string& name) {
+ // We assume that soname equals to basename here
+
+ // TODO(dimitry): consider having honest absolute-path -> soname resolution
+ // note that since we might end up refusing to load this library because
+ // it is not in shared libs list we need to get the soname without actually loading
+ // the library.
+ //
+ // On the other hand there are several places where we already assume that
+ // soname == basename in particular for any not-loaded library mentioned
+ // in DT_NEEDED list.
+ return basename(name.c_str());
+}
+
+static bool maybe_accessible_via_namespace_links(android_namespace_t* ns, const char* name) {
+ std::string soname = resolve_soname(name);
+ for (auto& ns_link : ns->linked_namespaces()) {
+ if (ns_link.is_accessible(soname.c_str())) {
+ return true;
+ }
+ }
+
+ return false;
+}
+
// TODO(dimitry): The grey-list is a workaround for http://b/26394120 ---
// gradually remove libraries from this list until it is gone.
-static bool is_greylisted(const char* name, const soinfo* needed_by) {
+static bool is_greylisted(android_namespace_t* ns, const char* name, const soinfo* needed_by) {
static const char* const kLibraryGreyList[] = {
"libandroid_runtime.so",
"libbinder.so",
@@ -160,10 +185,10 @@
}
// if the library needed by a system library - implicitly assume it
- // is greylisted
-
+ // is greylisted unless it is in the list of shared libraries for one or
+ // more linked namespaces
if (needed_by != nullptr && is_system_library(needed_by->get_realpath())) {
- return true;
+ return !maybe_accessible_via_namespace_links(ns, name);
}
// if this is an absolute path - make sure it points to /system/lib(64)
@@ -1048,7 +1073,7 @@
}
// TODO(dimitry): workaround for http://b/26394120 (the grey-list)
- if (fd == -1 && ns != &g_default_namespace && is_greylisted(name, needed_by)) {
+ if (fd == -1 && ns != &g_default_namespace && is_greylisted(ns, name, needed_by)) {
// try searching for it on default_namespace default_library_path
fd = open_library_on_paths(zip_archive_cache, name, file_offset,
g_default_namespace.get_default_library_paths(), realpath);
@@ -1144,7 +1169,7 @@
// TODO(dimitry) before O release: add a namespace attribute to have this enabled
// only for classloader-namespaces
const soinfo* needed_by = task->is_dt_needed() ? task->get_needed_by() : nullptr;
- if (is_greylisted(name, needed_by)) {
+ if (is_greylisted(ns, name, needed_by)) {
// print warning only if needed by non-system library
if (needed_by == nullptr || !is_system_library(needed_by->get_realpath())) {
const soinfo* needed_or_dlopened_by = task->get_needed_by();
@@ -1165,15 +1190,18 @@
DL_ERR("library \"%s\" needed or dlopened by \"%s\" is not accessible for the namespace \"%s\"",
name, needed_or_dlopened_by, ns->get_name());
- PRINT("library \"%s\" (\"%s\") needed or dlopened by \"%s\" is not accessible for the"
- " namespace: [name=\"%s\", ld_library_paths=\"%s\", default_library_paths=\"%s\","
- " permitted_paths=\"%s\"]",
- name, realpath.c_str(),
- needed_or_dlopened_by,
- ns->get_name(),
- android::base::Join(ns->get_ld_library_paths(), ':').c_str(),
- android::base::Join(ns->get_default_library_paths(), ':').c_str(),
- android::base::Join(ns->get_permitted_paths(), ':').c_str());
+ // do not print this if a library is in the list of shared libraries for linked namespaces
+ if (!maybe_accessible_via_namespace_links(ns, name)) {
+ PRINT("library \"%s\" (\"%s\") needed or dlopened by \"%s\" is not accessible for the"
+ " namespace: [name=\"%s\", ld_library_paths=\"%s\", default_library_paths=\"%s\","
+ " permitted_paths=\"%s\"]",
+ name, realpath.c_str(),
+ needed_or_dlopened_by,
+ ns->get_name(),
+ android::base::Join(ns->get_ld_library_paths(), ':').c_str(),
+ android::base::Join(ns->get_default_library_paths(), ':').c_str(),
+ android::base::Join(ns->get_permitted_paths(), ':').c_str());
+ }
return false;
}
}
@@ -1275,21 +1303,6 @@
});
}
-static std::string resolve_soname(const std::string& name) {
- // We assume that soname equals to basename here
-
- // TODO(dimitry): consider having honest absolute-path -> soname resolution
- // note that since we might end up refusing to load this library because
- // it is not in shared libs list we need to get the soname without actually loading
- // the library.
- //
- // On the other hand there are several places where we already assume that
- // soname == basename in particular for any not-loaded library mentioned
- // in DT_NEEDED list.
- return basename(name.c_str());
-}
-
-
static bool find_library_in_linked_namespace(const android_namespace_link_t& namespace_link,
LoadTask* task,
int rtld_flags) {
diff --git a/tests/dlext_test.cpp b/tests/dlext_test.cpp
index 17e1a48..808b708 100644
--- a/tests/dlext_test.cpp
+++ b/tests/dlext_test.cpp
@@ -917,12 +917,19 @@
extinfo.flags = ANDROID_DLEXT_USE_NAMESPACE;
extinfo.library_namespace = ns;
+ // An app targeting M can open libnativehelper.so because it's on the greylist.
android_set_application_target_sdk_version(__ANDROID_API_M__);
void* handle = android_dlopen_ext("libnativehelper.so", RTLD_NOW, &extinfo);
ASSERT_TRUE(handle != nullptr) << dlerror();
+ // Check that loader did not load another copy of libdl.so while loading greylisted library.
+ void* dlsym_ptr = dlsym(handle, "dlsym");
+ ASSERT_TRUE(dlsym_ptr != nullptr) << dlerror();
+ ASSERT_EQ(&dlsym, dlsym_ptr);
+
dlclose(handle);
+ // An app targeting N no longer has the greylist.
android_set_application_target_sdk_version(__ANDROID_API_N__);
handle = android_dlopen_ext("libnativehelper.so", RTLD_NOW, &extinfo);
ASSERT_TRUE(handle == nullptr);
diff --git a/tests/dlfcn_test.cpp b/tests/dlfcn_test.cpp
index 48fb6d1..0f24170 100644
--- a/tests/dlfcn_test.cpp
+++ b/tests/dlfcn_test.cpp
@@ -916,11 +916,6 @@
#endif
}
-#if defined(__LP64__)
-#define PATH_TO_SYSTEM_LIB "/system/lib64/"
-#else
-#define PATH_TO_SYSTEM_LIB "/system/lib/"
-#endif
#if defined (__aarch64__)
#define ALTERNATE_PATH_TO_SYSTEM_LIB "/system/lib/arm64/"
#elif defined (__arm__)
diff --git a/tests/utils.h b/tests/utils.h
index eac6f31..31974d0 100644
--- a/tests/utils.h
+++ b/tests/utils.h
@@ -32,6 +32,12 @@
#include "private/ScopeGuard.h"
+#if defined(__LP64__)
+#define PATH_TO_SYSTEM_LIB "/system/lib64/"
+#else
+#define PATH_TO_SYSTEM_LIB "/system/lib/"
+#endif
+
#if defined(__BIONIC__)
#define KNOWN_FAILURE_ON_BIONIC(x) xfail_ ## x
#else