| // Copyright 2018 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| // A crazy linker test to: |
| // - Load a library (libzoo) with the crazy linker. |
| // - Find the address of the "Zoo" function in libzoo. |
| // - Load a library (libbar) with the *system* linker. |
| // - Call the Zoo() function, passing the handle for libbar to it. |
| // |
| // Zoo() will call the crazy wrapper for dlsym() with a system handle. |
| // The wrapper is supposed to recognize the handle as not one of its |
| // own and fall-back to the system dlsym(). |
| // |
| // This will allow the function to find "Bar" within libbar() |
| // then call it. After that, Zoo() wll call the crazy wrapper for |
| // dlclose() with the same handle. The wrapper should recognize |
| // this and close bar as well. |
| // |
| // Finally, Zoo() will return the address of dlclose() as it |
| // sees it, which should be the address of the crazy wrapper for |
| // it, as checked by this program at the end of main(). |
| |
| #include <crazy_linker.h> |
| #include <dlfcn.h> |
| #include <stdio.h> |
| |
| #include "test_util.h" |
| |
| using dlclose_func_t = int(void*); |
| using zoo_func_t = dlclose_func_t*(void*); |
| |
| namespace crazy { |
| extern void* GetDlCloseWrapperAddressForTesting(); |
| } // namespace crazy |
| |
| #define LIB_NAME "libcrazy_linker_tests_libzoo_with_dlopen_handle.so" |
| #define LIB2_NAME "libcrazy_linker_tests_libbar.so" |
| |
| int main() { |
| crazy_context_t* context = crazy_context_create(); |
| crazy_library_t* library; |
| |
| // Load libzoo.so |
| if (!crazy_library_open(&library, LIB_NAME, context)) { |
| Panic("Could not open library: %s\n", crazy_context_get_error(context)); |
| } |
| |
| // Find the "Zoo" symbol. |
| zoo_func_t* zoo_func; |
| if (!crazy_library_find_symbol(library, "Zoo", |
| reinterpret_cast<void**>(&zoo_func))) { |
| Panic("Could not find 'Zoo' in %s\n", LIB_NAME); |
| } |
| printf("OK: Found 'Zoo' at %p in %s\n", zoo_func, LIB_NAME); |
| |
| // Open the 2nd library with the system linker. |
| void* bar_lib = ::dlopen(LIB2_NAME, RTLD_NOW); |
| if (!bar_lib) { |
| Panic("Could not open %s: %s\n", LIB2_NAME, dlerror()); |
| } |
| |
| printf("OK: Loaded libbar @%p with system linker\n", bar_lib); |
| |
| // Call Zoo(), passing the system handle to the second library. |
| dlclose_func_t* ret = (*zoo_func)(bar_lib); |
| if (!ret) |
| Panic("'Zoo' function failed (returned nullptr)!\n"); |
| |
| auto* expected_ret = reinterpret_cast<dlclose_func_t*>( |
| crazy::GetDlCloseWrapperAddressForTesting()); |
| |
| if (ret == &::dlclose) { |
| Panic("'Zoo' returned system dlclose() @%p, expected wrapper @%p\n", |
| &::dlclose, expected_ret); |
| } |
| if (ret != expected_ret) { |
| Panic("'Zoo' returned unknown address %p, expected wrapper @%p\n", ret, |
| expected_ret); |
| } |
| |
| printf("OK: Returned address was dlclose wrapper\n"); |
| |
| // Close the 1st library. |
| printf("Closing %s\n", LIB_NAME); |
| crazy_library_close(library); |
| |
| crazy_context_destroy(context); |
| |
| return 0; |
| } |