Fix relocation to look for symbols in local group
The local group is a sequence of libraries in default (breadth-first)
order. It allows RTLD_LOCALLY loaded library to correctly relocate
symbols within its group (see test-cases).
Local group lookup is performed after main executable and ld_preloads.
Bug: 2643900
Bug: 15432753
Change-Id: I9bb013b46d17dbb5cbdfb8fef26f552748385541
diff --git a/tests/dlfcn_test.cpp b/tests/dlfcn_test.cpp
index 1d7c29a..2ab3dc1 100644
--- a/tests/dlfcn_test.cpp
+++ b/tests/dlfcn_test.cpp
@@ -162,39 +162,39 @@
ASSERT_EQ(1, fn());
}
-TEST(dlfcn, dlopen_check_order) {
+TEST(dlfcn, dlopen_check_order_dlsym) {
// Here is how the test library and its dt_needed
// libraries are arranged
//
- // libtest_check_order.so
+ // libtest_check_order_children.so
// |
- // +-> libtest_check_order_1_left.so
+ // +-> ..._1_left.so
// | |
- // | +-> libtest_check_order_a.so
+ // | +-> ..._a.so
// | |
- // | +-> libtest_check_order_b.so
+ // | +-> ...r_b.so
// |
- // +-> libtest_check_order_2_right.so
+ // +-> ..._2_right.so
// | |
- // | +-> libtest_check_order_d.so
+ // | +-> ..._d.so
// | |
- // | +-> libtest_check_order_b.so
+ // | +-> ..._b.so
// |
- // +-> libtest_check_order_3_c.so
+ // +-> ..._3_c.so
//
// load order should be (1, 2, 3, a, b, d)
//
// get_answer() is defined in (2, 3, a, b, c)
// get_answer2() is defined in (b, d)
- void* sym = dlsym(RTLD_DEFAULT, "dlopen_test_get_answer");
+ void* sym = dlsym(RTLD_DEFAULT, "check_order_dlsym_get_answer");
ASSERT_TRUE(sym == nullptr);
- void* handle = dlopen("libtest_check_order.so", RTLD_NOW | RTLD_GLOBAL);
- ASSERT_TRUE(handle != nullptr);
+ void* handle = dlopen("libtest_check_order_dlsym.so", RTLD_NOW | RTLD_GLOBAL);
+ ASSERT_TRUE(handle != nullptr) << dlerror();
typedef int (*fn_t) (void);
fn_t fn, fn2;
- fn = reinterpret_cast<fn_t>(dlsym(RTLD_DEFAULT, "dlopen_test_get_answer"));
+ fn = reinterpret_cast<fn_t>(dlsym(RTLD_DEFAULT, "check_order_dlsym_get_answer"));
ASSERT_TRUE(fn != NULL) << dlerror();
- fn2 = reinterpret_cast<fn_t>(dlsym(RTLD_DEFAULT, "dlopen_test_get_answer2"));
+ fn2 = reinterpret_cast<fn_t>(dlsym(RTLD_DEFAULT, "check_order_dlsym_get_answer2"));
ASSERT_TRUE(fn2 != NULL) << dlerror();
ASSERT_EQ(42, fn());
@@ -202,6 +202,163 @@
dlclose(handle);
}
+TEST(dlfcn, dlopen_check_order_reloc_siblings) {
+ // This is how this one works:
+ // we lookup and call get_answer which is defined in '_2.so'
+ // and in turn calls external get_answer_impl() defined in _1.so and in '_[a-f].so'
+ // the correct _impl() is implemented by '_a.so';
+ //
+ // Note that this is test for RTLD_LOCAL (TODO: test for GLOBAL?)
+ //
+ // Here is the picture:
+ //
+ // libtest_check_order_reloc_siblings.so
+ // |
+ // +-> ..._1.so <- empty
+ // | |
+ // | +-> ..._a.so <- exports correct answer_impl()
+ // | |
+ // | +-> ..._b.so <- every other letter exporting incorrect one.
+ // |
+ // +-> ..._2.so <- empty
+ // | |
+ // | +-> ..._c.so
+ // | |
+ // | +-> ..._d.so
+ // |
+ // +-> ..._3.so <- empty
+ // |
+ // +-> ..._e.so
+ // |
+ // +-> ..._f.so <- exports get_answer() that calls get_anser_impl();
+ // implements incorrect get_answer_impl()
+
+ void* handle = dlopen("libtest_check_order_reloc_siblings.so", RTLD_NOW | RTLD_NOLOAD);
+ ASSERT_TRUE(handle == nullptr);
+#ifdef __BIONIC__
+ // TODO: glibc returns nullptr on dlerror() here. Is it bug?
+ ASSERT_STREQ("dlopen failed: library \"libtest_check_order_reloc_siblings.so\" wasn't loaded and RTLD_NOLOAD prevented it", dlerror());
+#endif
+
+ handle = dlopen("libtest_check_order_reloc_siblings.so", RTLD_NOW | RTLD_LOCAL);
+ ASSERT_TRUE(handle != nullptr) << dlerror();
+
+ typedef int (*fn_t) (void);
+ fn_t fn = reinterpret_cast<fn_t>(dlsym(handle, "check_order_reloc_get_answer"));
+ ASSERT_TRUE(fn != nullptr) << dlerror();
+ ASSERT_EQ(42, fn());
+
+ ASSERT_EQ(0, dlclose(handle));
+}
+
+TEST(dlfcn, dlopen_check_order_reloc_siblings_with_preload) {
+ // This test uses the same library as dlopen_check_order_reloc_siblings.
+ // Unlike dlopen_check_order_reloc_siblings it preloads
+ // libtest_check_order_reloc_siblings_1.so (first dependency) prior to
+ // dlopen(libtest_check_order_reloc_siblings.so)
+
+ void* handle = dlopen("libtest_check_order_reloc_siblings.so", RTLD_NOW | RTLD_NOLOAD);
+ ASSERT_TRUE(handle == nullptr);
+ handle = dlopen("libtest_check_order_reloc_siblings_1.so", RTLD_NOW | RTLD_NOLOAD);
+ ASSERT_TRUE(handle == nullptr);
+
+ void* handle_for_1 = dlopen("libtest_check_order_reloc_siblings_1.so", RTLD_NOW | RTLD_LOCAL);
+ ASSERT_TRUE(handle_for_1 != nullptr) << dlerror();
+
+ handle = dlopen("libtest_check_order_reloc_siblings.so", RTLD_NOW | RTLD_LOCAL);
+ ASSERT_TRUE(handle != nullptr) << dlerror();
+
+ ASSERT_EQ(0, dlclose(handle_for_1));
+
+ typedef int (*fn_t) (void);
+ fn_t fn = reinterpret_cast<fn_t>(dlsym(handle, "check_order_reloc_get_answer"));
+ ASSERT_TRUE(fn != nullptr) << dlerror();
+ ASSERT_EQ(42, fn());
+
+ ASSERT_EQ(0, dlclose(handle));
+}
+
+TEST(dlfcn, dlopen_check_order_reloc_nephew) {
+ // This is how this one works:
+ // we lookup and call nephew_get_answer which is defined in '_2.so'
+ // and in turn calls external get_answer_impl() defined in '_[a-f].so'
+ // the correct _impl() is implemented by '_a.so';
+ //
+ // Here is the picture:
+ //
+ // libtest_check_order_reloc_siblings.so
+ // |
+ // +-> ..._1.so <- empty
+ // | |
+ // | +-> ..._a.so <- exports correct answer_impl()
+ // | |
+ // | +-> ..._b.so <- every other letter exporting incorrect one.
+ // |
+ // +-> ..._2.so <- empty
+ // | |
+ // | +-> ..._c.so
+ // | |
+ // | +-> ..._d.so
+ // |
+ // +-> ..._3.so <- nephew_get_answer() that calls get_answer_impl();
+ // |
+ // +-> ..._e.so
+ // |
+ // +-> ..._f.so
+
+ void* handle = dlopen("libtest_check_order_reloc_siblings.so", RTLD_NOW | RTLD_NOLOAD);
+ ASSERT_TRUE(handle == nullptr);
+#ifdef __BIONIC__
+ // TODO: glibc returns nullptr on dlerror() here. Is it bug?
+ ASSERT_STREQ("dlopen failed: library \"libtest_check_order_reloc_siblings.so\" wasn't loaded and RTLD_NOLOAD prevented it", dlerror());
+#endif
+
+ handle = dlopen("libtest_check_order_reloc_siblings.so", RTLD_NOW | RTLD_LOCAL);
+ ASSERT_TRUE(handle != nullptr) << dlerror();
+
+ typedef int (*fn_t) (void);
+ fn_t fn = reinterpret_cast<fn_t>(dlsym(handle, "check_order_reloc_nephew_get_answer"));
+ ASSERT_TRUE(fn != nullptr) << dlerror();
+ ASSERT_EQ(42, fn());
+
+ ASSERT_EQ(0, dlclose(handle));
+}
+
+extern "C" int check_order_reloc_root_get_answer_impl() {
+ return 42;
+}
+
+TEST(dlfcn, dlopen_check_order_reloc_main_executable) {
+ // This is how this one works:
+ // we lookup and call get_answer3 which is defined in 'root.so'
+ // and in turn calls external root_get_answer_impl() defined in _2.so and
+ // above the correct _impl() is one in the executable.
+ //
+ // libtest_check_order_reloc_root.so
+ // |
+ // +-> ..._1.so <- empty
+ // |
+ // +-> ..._2.so <- gives incorrect answer for answer_main_impl()
+ //
+
+ void* handle = dlopen("libtest_check_order_reloc_root.so", RTLD_NOW | RTLD_NOLOAD);
+ ASSERT_TRUE(handle == nullptr);
+#ifdef __BIONIC__
+ // TODO: glibc returns nullptr on dlerror() here. Is it bug?
+ ASSERT_STREQ("dlopen failed: library \"libtest_check_order_reloc_root.so\" wasn't loaded and RTLD_NOLOAD prevented it", dlerror());
+#endif
+
+ handle = dlopen("libtest_check_order_reloc_root.so", RTLD_NOW | RTLD_LOCAL);
+ ASSERT_TRUE(handle != nullptr) << dlerror();
+
+ typedef int (*fn_t) (void);
+ fn_t fn = reinterpret_cast<fn_t>(dlsym(handle, "check_order_reloc_root_get_answer"));
+ ASSERT_TRUE(fn != nullptr) << dlerror();
+ ASSERT_EQ(42, fn());
+
+ ASSERT_EQ(0, dlclose(handle));
+}
+
TEST(dlfcn, dlopen_check_rtld_local) {
void* sym = dlsym(RTLD_DEFAULT, "dlopen_testlib_simple_func");
ASSERT_TRUE(sym == nullptr);
@@ -342,7 +499,6 @@
ASSERT_TRUE(!is_unloaded);
}
-
TEST(dlfcn, dlopen_failure) {
void* self = dlopen("/does/not/exist", RTLD_NOW);
ASSERT_TRUE(self == NULL);