Improved dlsym tests and fixes to linker
Answers the question: what if dependent library
was preloaded with RTLD_LOCAL flag.
Also add test for RTLD_NEXT within local_group.
Bug: http://b/17512583
Change-Id: I79e081e68b3a8c0ed8980d4275a06515fea94ec9
(cherry picked from commit 697bd9fd38ab078a117ad9a5777cf286c467b9b9)
diff --git a/linker/linker.cpp b/linker/linker.cpp
index c6decee..64b6d4d 100644
--- a/linker/linker.cpp
+++ b/linker/linker.cpp
@@ -933,13 +933,17 @@
}
-// This is used by dlsym(3). It performs symbol lookup only within the
-// specified soinfo object and its dependencies in breadth first order.
-const ElfW(Sym)* dlsym_handle_lookup(soinfo* si, soinfo** found, const char* name) {
+static const ElfW(Sym)* dlsym_handle_lookup(soinfo* root, soinfo* skip_until,
+ soinfo** found, SymbolName& symbol_name) {
const ElfW(Sym)* result = nullptr;
- SymbolName symbol_name(name);
+ bool skip_lookup = skip_until != nullptr;
- walk_dependencies_tree(&si, 1, [&](soinfo* current_soinfo) {
+ walk_dependencies_tree(&root, 1, [&](soinfo* current_soinfo) {
+ if (skip_lookup) {
+ skip_lookup = current_soinfo != skip_until;
+ return true;
+ }
+
if (!current_soinfo->find_symbol_by_name(symbol_name, nullptr, &result)) {
result = nullptr;
return false;
@@ -956,6 +960,13 @@
return result;
}
+// This is used by dlsym(3). It performs symbol lookup only within the
+// specified soinfo object and its dependencies in breadth first order.
+const ElfW(Sym)* dlsym_handle_lookup(soinfo* si, soinfo** found, const char* name) {
+ SymbolName symbol_name(name);
+ return dlsym_handle_lookup(si, nullptr, found, symbol_name);
+}
+
/* This is used by dlsym(3) to performs a global symbol lookup. If the
start value is null (for RTLD_DEFAULT), the search starts at the
beginning of the global solist. Otherwise the search starts at the
@@ -993,31 +1004,13 @@
}
}
- // If not found - look into local_group unless
- // caller is part of the global group in which
+ // If not found - use dlsym_handle_lookup for caller's
+ // local_group unless it is part of the global group in which
// case we already did it.
if (s == nullptr && caller != nullptr &&
(caller->get_rtld_flags() & RTLD_GLOBAL) == 0) {
- soinfo* local_group_root = caller->get_local_group_root();
-
- if (handle == RTLD_DEFAULT) {
- start = local_group_root;
- }
-
- for (soinfo* si = start; si != nullptr; si = si->next) {
- if (si->get_local_group_root() != local_group_root) {
- break;
- }
-
- if (!si->find_symbol_by_name(symbol_name, nullptr, &s)) {
- return nullptr;
- }
-
- if (s != nullptr) {
- *found = si;
- break;
- }
- }
+ return dlsym_handle_lookup(caller->get_local_group_root(),
+ (handle == RTLD_NEXT) ? caller : nullptr, found, symbol_name);
}
if (s != nullptr) {
diff --git a/tests/dlfcn_test.cpp b/tests/dlfcn_test.cpp
index 6b1f109..a5abda7 100644
--- a/tests/dlfcn_test.cpp
+++ b/tests/dlfcn_test.cpp
@@ -71,23 +71,80 @@
void* handle = dlopen("libtest_dlsym_from_this.so", RTLD_LAZY | RTLD_LOCAL);
ASSERT_TRUE(handle != nullptr) << dlerror();
- // check that we cant find '_test_dlsym_symbol' via dlsym(RTLD_DEFAULT)
+ // check that we can't find '_test_dlsym_symbol' via dlsym(RTLD_DEFAULT)
void* symbol = dlsym(RTLD_DEFAULT, "test_dlsym_symbol");
ASSERT_TRUE(symbol == nullptr);
ASSERT_SUBSTR("undefined symbol: test_dlsym_symbol", dlerror());
typedef int* (*fn_t)();
- fn_t fn = reinterpret_cast<fn_t>(dlsym(handle, "lookup_dlsym_symbol_using_RTLD_DEFAULT"));
+ fn_t lookup_dlsym_symbol_using_RTLD_DEFAULT =
+ reinterpret_cast<fn_t>(dlsym(handle, "lookup_dlsym_symbol_using_RTLD_DEFAULT"));
+ ASSERT_TRUE(lookup_dlsym_symbol_using_RTLD_DEFAULT != nullptr) << dlerror();
- ASSERT_TRUE(fn != nullptr) << dlerror();
-
- int* ptr = fn();
+ int* ptr = lookup_dlsym_symbol_using_RTLD_DEFAULT();
ASSERT_TRUE(ptr != nullptr) << dlerror();
ASSERT_EQ(42, *ptr);
+ fn_t lookup_dlsym_symbol2_using_RTLD_DEFAULT =
+ reinterpret_cast<fn_t>(dlsym(handle, "lookup_dlsym_symbol2_using_RTLD_DEFAULT"));
+ ASSERT_TRUE(lookup_dlsym_symbol2_using_RTLD_DEFAULT != nullptr) << dlerror();
+
+ ptr = lookup_dlsym_symbol2_using_RTLD_DEFAULT();
+ ASSERT_TRUE(ptr != nullptr) << dlerror();
+ ASSERT_EQ(44, *ptr);
+
+ fn_t lookup_dlsym_symbol_using_RTLD_NEXT =
+ reinterpret_cast<fn_t>(dlsym(handle, "lookup_dlsym_symbol_using_RTLD_NEXT"));
+ ASSERT_TRUE(lookup_dlsym_symbol_using_RTLD_NEXT != nullptr) << dlerror();
+
+ ptr = lookup_dlsym_symbol_using_RTLD_NEXT();
+ ASSERT_TRUE(ptr != nullptr) << dlerror();
+ ASSERT_EQ(43, *ptr);
+
dlclose(handle);
}
+TEST(dlfcn, dlsym_from_sofile_with_preload) {
+ void* preload = dlopen("libtest_dlsym_from_this_grandchild.so", RTLD_NOW | RTLD_LOCAL);
+ ASSERT_TRUE(preload != nullptr) << dlerror();
+
+ void* handle = dlopen("libtest_dlsym_from_this.so", RTLD_NOW | RTLD_LOCAL);
+ ASSERT_TRUE(handle != nullptr) << dlerror();
+
+ // check that we can't find '_test_dlsym_symbol' via dlsym(RTLD_DEFAULT)
+ void* symbol = dlsym(RTLD_DEFAULT, "test_dlsym_symbol");
+ ASSERT_TRUE(symbol == nullptr);
+ ASSERT_SUBSTR("undefined symbol: test_dlsym_symbol", dlerror());
+
+ typedef int* (*fn_t)();
+ fn_t lookup_dlsym_symbol_using_RTLD_DEFAULT =
+ reinterpret_cast<fn_t>(dlsym(handle, "lookup_dlsym_symbol_using_RTLD_DEFAULT"));
+ ASSERT_TRUE(lookup_dlsym_symbol_using_RTLD_DEFAULT != nullptr) << dlerror();
+
+ int* ptr = lookup_dlsym_symbol_using_RTLD_DEFAULT();
+ ASSERT_TRUE(ptr != nullptr) << dlerror();
+ ASSERT_EQ(42, *ptr);
+
+ fn_t lookup_dlsym_symbol2_using_RTLD_DEFAULT =
+ reinterpret_cast<fn_t>(dlsym(handle, "lookup_dlsym_symbol2_using_RTLD_DEFAULT"));
+ ASSERT_TRUE(lookup_dlsym_symbol2_using_RTLD_DEFAULT != nullptr) << dlerror();
+
+ ptr = lookup_dlsym_symbol2_using_RTLD_DEFAULT();
+ ASSERT_TRUE(ptr != nullptr) << dlerror();
+ ASSERT_EQ(44, *ptr);
+
+ fn_t lookup_dlsym_symbol_using_RTLD_NEXT =
+ reinterpret_cast<fn_t>(dlsym(handle, "lookup_dlsym_symbol_using_RTLD_NEXT"));
+ ASSERT_TRUE(lookup_dlsym_symbol_using_RTLD_NEXT != nullptr) << dlerror();
+
+ ptr = lookup_dlsym_symbol_using_RTLD_NEXT();
+ ASSERT_TRUE(ptr != nullptr) << dlerror();
+ ASSERT_EQ(43, *ptr);
+
+ dlclose(handle);
+ dlclose(preload);
+}
+
TEST(dlfcn, dlsym_with_dependencies) {
void* handle = dlopen("libtest_with_dependency.so", RTLD_NOW);
ASSERT_TRUE(handle != NULL);
diff --git a/tests/libs/Android.mk b/tests/libs/Android.mk
index c432c2e..4e275ed 100644
--- a/tests/libs/Android.mk
+++ b/tests/libs/Android.mk
@@ -385,11 +385,26 @@
# -----------------------------------------------------------------------------
# Library to check RTLD_LOCAL with dlsym in 'this'
# -----------------------------------------------------------------------------
-libtest_dlsym_from_this_src_files := dlsym_from_this.cpp
+libtest_dlsym_from_this_src_files := dlsym_from_this_symbol.cpp
+
+libtest_dlsym_from_this_shared_libraries_target := libdl
+libtest_dlsym_from_this_shared_libraries := libtest_dlsym_from_this_child
module := libtest_dlsym_from_this
-libtest_dlsym_from_this_shared_libraries_target := libdl
+include $(LOCAL_PATH)/Android.build.testlib.mk
+# -----------------------------------------------------------------------------
+libtest_dlsym_from_this_child_src_files := dlsym_from_this_functions.cpp
+
+libtest_dlsym_from_this_child_shared_libraries := libtest_dlsym_from_this_grandchild
+
+module := libtest_dlsym_from_this_child
+include $(LOCAL_PATH)/Android.build.testlib.mk
+
+# -----------------------------------------------------------------------------
+libtest_dlsym_from_this_grandchild_src_files := dlsym_from_this_symbol2.cpp
+
+module := libtest_dlsym_from_this_grandchild
include $(LOCAL_PATH)/Android.build.testlib.mk
# -----------------------------------------------------------------------------
diff --git a/tests/libs/dlsym_from_this_functions.cpp b/tests/libs/dlsym_from_this_functions.cpp
new file mode 100644
index 0000000..1f357e0
--- /dev/null
+++ b/tests/libs/dlsym_from_this_functions.cpp
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include <dlfcn.h>
+#include <stdio.h>
+
+extern int test_dlsym_symbol;
+
+int test_dlsym_symbol = -1;
+
+extern "C" int* lookup_dlsym_symbol_using_RTLD_DEFAULT() {
+ dlerror();
+ int* result = static_cast<int*>(dlsym(RTLD_DEFAULT, "test_dlsym_symbol"));
+ // TODO: remove this once b/20049306 is fixed
+ if (result == nullptr) {
+ printf("Cannot find the answer\n");
+ }
+ return result;
+}
+
+extern "C" int* lookup_dlsym_symbol2_using_RTLD_DEFAULT() {
+ dlerror();
+ int* result = static_cast<int*>(dlsym(RTLD_DEFAULT, "test_dlsym_symbol2"));
+ // TODO: remove this once b/20049306 is fixed
+ if (result == nullptr) {
+ printf("Cannot find the answer\n");
+ }
+ return result;
+}
+
+extern "C" int* lookup_dlsym_symbol_using_RTLD_NEXT() {
+ dlerror();
+ int* result = static_cast<int*>(dlsym(RTLD_NEXT, "test_dlsym_symbol"));
+ // TODO: remove this once b/20049306 is fixed
+ if (result == nullptr) {
+ printf("Cannot find the answer\n");
+ }
+ return result;
+}
+
diff --git a/tests/libs/dlsym_from_this.cpp b/tests/libs/dlsym_from_this_symbol.cpp
similarity index 60%
rename from tests/libs/dlsym_from_this.cpp
rename to tests/libs/dlsym_from_this_symbol.cpp
index b5215c9..c3ec255 100644
--- a/tests/libs/dlsym_from_this.cpp
+++ b/tests/libs/dlsym_from_this_symbol.cpp
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2014 The Android Open Source Project
+ * Copyright (C) 2015 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
@@ -13,18 +13,5 @@
* See the License for the specific language governing permissions and
* limitations under the License.
*/
-#include <dlfcn.h>
-#include <stdio.h>
int test_dlsym_symbol = 42;
-
-extern "C" int* lookup_dlsym_symbol_using_RTLD_DEFAULT() {
- dlerror();
- int* result = static_cast<int*>(dlsym(RTLD_DEFAULT, "test_dlsym_symbol"));
- // TODO: remove this once b/20049306 is fixed
- if (result == nullptr) {
- printf("Cannot find the answer\n");
- }
- return result;
-}
-
diff --git a/tests/libs/dlsym_from_this_symbol2.cpp b/tests/libs/dlsym_from_this_symbol2.cpp
new file mode 100644
index 0000000..20da1d5
--- /dev/null
+++ b/tests/libs/dlsym_from_this_symbol2.cpp
@@ -0,0 +1,18 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+int test_dlsym_symbol = 43;
+int test_dlsym_symbol2 = 44;