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Rename linker greylist to exempt-list

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Update a comment in android-changes-for-ndk-developers.md about the
removed debug.ld.greylist_disabled system property.

Update language to comply with Android's inclusive language guidance

  #inclusivefixit

See https://source.android.com/setup/contribute/respectful-code for reference

Bug: http://b/162536543
Test: bionic-unit-tests
Change-Id: I760ee14bce14d9d799926c43d2c14fd8ffbc6968
This commit is contained in:
Ryan Prichard 2020-08-03 15:29:12 -07:00
parent 95dbcfaf04
commit aff9a34bd8
6 changed files with 35 additions and 37 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

8
android-changes-for-ndk-developers.md
View file

@ -175,11 +175,9 @@ and libssl.so). In order to give you more time to transition, we will
temporarily support these libraries; so if you see a warning that means
your code will not work in a future release -- please fix it now!
In O and later, the system property `debug.ld.greylist_disabled` can be
used to deny access to the greylist even to an app that would normally
be allowed it. This allows you to test compatibility without bumping the
app's `targetSdkVersion`. Use `setprop debug.ld.greylist_disabled true`
to turn this on (any other value leaves the greylist enabled).
Between O and R, this compatibility mode could be disabled by setting a
system property (`debug.ld.greylist_disabled`). This property is ignored
in S and later.
```
$ readelf --dynamic libBroken.so | grep NEEDED

36
linker/linker.cpp
View file

@ -186,10 +186,10 @@ static bool maybe_accessible_via_namespace_links(android_namespace_t* ns, const
return false;
}
// TODO(dimitry): The grey-list is a workaround for http://b/26394120 ---
// TODO(dimitry): The exempt-list is a workaround for http://b/26394120 ---
// gradually remove libraries from this list until it is gone.
static bool is_greylisted(android_namespace_t* ns, const char* name, const soinfo* needed_by) {
static const char* const kLibraryGreyList[] = {
static bool is_exempt_lib(android_namespace_t* ns, const char* name, const soinfo* needed_by) {
static const char* const kLibraryExemptList[] = {
"libandroid_runtime.so",
"libbinder.so",
"libcrypto.so",
@ -206,13 +206,13 @@ static bool is_greylisted(android_namespace_t* ns, const char* name, const soinf
nullptr
};
// If you're targeting N, you don't get the greylist.
// If you're targeting N, you don't get the exempt-list.
if (get_application_target_sdk_version() >= 24) {
return false;
}
// if the library needed by a system library - implicitly assume it
// is greylisted unless it is in the list of shared libraries for one or
// is exempt 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 !maybe_accessible_via_namespace_links(ns, name);
@ -224,8 +224,8 @@ static bool is_greylisted(android_namespace_t* ns, const char* name, const soinf
name = basename(name);
}
for (size_t i = 0; kLibraryGreyList[i] != nullptr; ++i) {
if (strcmp(name, kLibraryGreyList[i]) == 0) {
for (size_t i = 0; kLibraryExemptList[i] != nullptr; ++i) {
if (strcmp(name, kLibraryExemptList[i]) == 0) {
return true;
}
}
@ -632,7 +632,7 @@ class LoadTask {
bool close_fd_;
off64_t file_offset_;
std::unordered_map<const soinfo*, ElfReader>* elf_readers_map_;
// TODO(dimitry): needed by workaround for http://b/26394120 (the grey-list)
// TODO(dimitry): needed by workaround for http://b/26394120 (the exempt-list)
bool is_dt_needed_;
// END OF WORKAROUND
const android_namespace_t* const start_from_;
@ -1187,12 +1187,12 @@ static bool load_library(android_namespace_t* ns,
// do not check accessibility using realpath if fd is located on tmpfs
// this enables use of memfd_create() for apps
if ((fs_stat.f_type != TMPFS_MAGIC) && (!ns->is_accessible(realpath))) {
// TODO(dimitry): workaround for http://b/26394120 - the grey-list
// TODO(dimitry): workaround for http://b/26394120 - the exempt-list
// 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(ns, name, needed_by)) {
if (is_exempt_lib(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();
@ -1446,14 +1446,14 @@ static bool find_library_internal(android_namespace_t* ns,
return true;
}
// TODO(dimitry): workaround for http://b/26394120 (the grey-list)
if (ns->is_greylist_enabled() && is_greylisted(ns, task->get_name(), task->get_needed_by())) {
// For the libs in the greylist, switch to the default namespace and then
// TODO(dimitry): workaround for http://b/26394120 (the exempt-list)
if (ns->is_exempt_list_enabled() && is_exempt_lib(ns, task->get_name(), task->get_needed_by())) {
// For the libs in the exempt-list, switch to the default namespace and then
// try the load again from there. The library could be loaded from the
// default namespace or from another namespace (e.g. runtime) that is linked
// from the default namespace.
LD_LOG(kLogDlopen,
"find_library_internal(ns=%s, task=%s): Greylisted library - trying namespace %s",
"find_library_internal(ns=%s, task=%s): Exempt system library - trying namespace %s",
ns->get_name(), task->get_name(), g_default_namespace.get_name());
ns = &g_default_namespace;
if (load_library(ns, task, zip_archive_cache, load_tasks, rtld_flags,
@ -1473,9 +1473,9 @@ static bool find_library_internal(android_namespace_t* ns,
// Library is already loaded.
if (task->get_soinfo() != nullptr) {
// n.b. This code path runs when find_library_in_linked_namespace found an already-loaded
// library by soname. That should only be possible with a greylist lookup, where we switch
// the namespace, because otherwise, find_library_in_linked_namespace is duplicating the
// soname scan done in this function's first call to find_loaded_library_by_soname.
// library by soname. That should only be possible with a exempt-list lookup, where we
// switch the namespace, because otherwise, find_library_in_linked_namespace is duplicating
// the soname scan done in this function's first call to find_loaded_library_by_soname.
return true;
}
@ -2426,7 +2426,7 @@ android_namespace_t* create_namespace(const void* caller_addr,
android_namespace_t* ns = new (g_namespace_allocator.alloc()) android_namespace_t();
ns->set_name(name);
ns->set_isolated((type & ANDROID_NAMESPACE_TYPE_ISOLATED) != 0);
ns->set_greylist_enabled((type & ANDROID_NAMESPACE_TYPE_GREYLIST_ENABLED) != 0);
ns->set_exempt_list_enabled((type & ANDROID_NAMESPACE_TYPE_EXEMPT_LIST_ENABLED) != 0);
ns->set_also_used_as_anonymous((type & ANDROID_NAMESPACE_TYPE_ALSO_USED_AS_ANONYMOUS) != 0);
if ((type & ANDROID_NAMESPACE_TYPE_SHARED) != 0) {

4
linker/linker.h
View file

@ -133,10 +133,10 @@ enum {
*/
ANDROID_NAMESPACE_TYPE_SHARED = 2,
/* This flag instructs linker to enable grey-list workaround for the namespace.
/* This flag instructs linker to enable exempt-list workaround for the namespace.
* See http://b/26394120 for details.
*/
ANDROID_NAMESPACE_TYPE_GREYLIST_ENABLED = 0x08000000,
ANDROID_NAMESPACE_TYPE_EXEMPT_LIST_ENABLED = 0x08000000,
/* This flag instructs linker to use this namespace as the anonymous
* namespace. There can be only one anonymous namespace in a process. If there

8
linker/linker_namespaces.h
View file

@ -76,7 +76,7 @@ struct android_namespace_t {
public:
android_namespace_t() :
is_isolated_(false),
is_greylist_enabled_(false),
is_exempt_list_enabled_(false),
is_also_used_as_anonymous_(false) {}
const char* get_name() const { return name_.c_str(); }
@ -85,8 +85,8 @@ struct android_namespace_t {
bool is_isolated() const { return is_isolated_; }
void set_isolated(bool isolated) { is_isolated_ = isolated; }
bool is_greylist_enabled() const { return is_greylist_enabled_; }
void set_greylist_enabled(bool enabled) { is_greylist_enabled_ = enabled; }
bool is_exempt_list_enabled() const { return is_exempt_list_enabled_; }
void set_exempt_list_enabled(bool enabled) { is_exempt_list_enabled_ = enabled; }
bool is_also_used_as_anonymous() const { return is_also_used_as_anonymous_; }
void set_also_used_as_anonymous(bool yes) { is_also_used_as_anonymous_ = yes; }
@ -169,7 +169,7 @@ struct android_namespace_t {
private:
std::string name_;
bool is_isolated_;
bool is_greylist_enabled_;
bool is_exempt_list_enabled_;
bool is_also_used_as_anonymous_;
std::vector<std::string> ld_library_paths_;
std::vector<std::string> default_library_paths_;

4
tests/dlext_private.h
View file

@ -56,10 +56,10 @@ enum {
*/
ANDROID_NAMESPACE_TYPE_SHARED = 2,
/* This flag instructs linker to enable grey-list workaround for the namespace.
/* This flag instructs linker to enable exempt-list workaround for the namespace.
* See http://b/26394120 for details.
*/
ANDROID_NAMESPACE_TYPE_GREYLIST_ENABLED = 0x08000000,
ANDROID_NAMESPACE_TYPE_EXEMPT_LIST_ENABLED = 0x08000000,
ANDROID_NAMESPACE_TYPE_SHARED_ISOLATED = ANDROID_NAMESPACE_TYPE_SHARED |
ANDROID_NAMESPACE_TYPE_ISOLATED,

12
tests/dlext_test.cpp
View file

@ -1228,7 +1228,7 @@ TEST(dlext, ns_unload_between_namespaces_missing_symbol_indirect) {
dlerror());
}
TEST(dlext, ns_greylist_enabled) {
TEST(dlext, ns_exempt_list_enabled) {
ASSERT_TRUE(android_init_anonymous_namespace(g_core_shared_libs.c_str(), nullptr));
const std::string ns_search_path = GetTestlibRoot() + "/private_namespace_libs";
@ -1237,7 +1237,7 @@ TEST(dlext, ns_greylist_enabled) {
android_create_namespace("namespace",
nullptr,
ns_search_path.c_str(),
ANDROID_NAMESPACE_TYPE_ISOLATED | ANDROID_NAMESPACE_TYPE_GREYLIST_ENABLED,
ANDROID_NAMESPACE_TYPE_ISOLATED | ANDROID_NAMESPACE_TYPE_EXEMPT_LIST_ENABLED,
nullptr,
nullptr);
@ -1247,26 +1247,26 @@ TEST(dlext, ns_greylist_enabled) {
extinfo.flags = ANDROID_DLEXT_USE_NAMESPACE;
extinfo.library_namespace = ns;
// An app targeting M can open libnativehelper.so because it's on the greylist.
// An app targeting M can open libnativehelper.so because it's on the exempt-list.
android_set_application_target_sdk_version(23);
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.
// Check that loader did not load another copy of libdl.so while loading exempted 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.
// An app targeting N no longer has the exempt-list.
android_set_application_target_sdk_version(24);
handle = android_dlopen_ext("libnativehelper.so", RTLD_NOW, &extinfo);
ASSERT_TRUE(handle == nullptr);
ASSERT_STREQ("dlopen failed: library \"libnativehelper.so\" not found", dlerror());
}
TEST(dlext, ns_greylist_disabled_by_default) {
TEST(dlext, ns_exempt_list_disabled_by_default) {
ASSERT_TRUE(android_init_anonymous_namespace(g_core_shared_libs.c_str(), nullptr));
const std::string ns_search_path = GetTestlibRoot() + "/private_namespace_libs";