| // 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.so) with the linker. |
| // - Find the address of the "Zoo" function in libzoo.so. |
| // - Call the Zoo() function, which will use dlopen() / dlsym() to |
| // find libbar.so (which depends on libfoo.so). |
| // - Close the library. |
| |
| // This tests the dlopen/dlsym/dlclose wrappers provided by the crazy |
| // linker to loaded libraries. |
| |
| #include <crazy_linker.h> |
| #include <stdio.h> |
| |
| #include "test_util.h" |
| |
| typedef bool (*FunctionPtr)(); |
| |
| #define LIB_NAME "libcrazy_linker_tests_libzoo_dlopen_in_initializer.so" |
| |
| int main() { |
| crazy_context_t* context = crazy_context_create(); |
| crazy_library_t* library; |
| |
| // Load library. Its ELF initializer will call dlopen() to open another |
| // library, the use dlsym() to find and invoke a function inside it. |
| // |
| // Said function will actually also call dlopen() to load another library |
| // and invoke another function in another library, i.e.: |
| // |
| // exe: crazy_library_open("libA.so") |
| // linker: load and relocate libA.so |
| // linker: call ELF initializers in libA.so |
| // libA.so: call dlopen("libB.so") |
| // linker: crazy::WrapDlOpen("libB.so") gets called. |
| // linker: load and relocate libB.so |
| // linker: run ELF initializer in libB.so |
| // libB.so: call dlopen() to load library C |
| // linker: crazy::WrapDlOpen("libC.so") gets called. |
| // linker: load and relocate libC.so |
| // libB.so: call dlsym() to locate C entry point |
| // libB.so: call C entry point. |
| // libC.so: call dlopen() to load library D |
| // linker: crazy::WrapDlOpen("libD.so") gets called. |
| // linker: load and relocate libD.so |
| // libC.so: call dlsym() to locate D entry point. |
| // libC.so: call D entry point |
| // libD.so: execute function and return. |
| // libC.so: call dlclose() to unload libD.so. |
| // libC.so: return from function |
| // libB.so: return from initializer |
| // linker: libB.so has finished loading. |
| // libA.so: call dlsym() to locate B entry point. |
| // libA.so: call B entry point. |
| // libB.so: execute function and return |
| // libA.so: call dlclose() to unload libB.so |
| // libA.so: return from initializer. |
| // linker: libA.so has finished loading. |
| // exe: crazy_library_find_symbol() to find A entry point |
| // libA.so: execute A function and return. |
| // exe: crazy_library_close() to unload libA.so |
| // linker: call ELF finalizers in libA.so |
| // libA.so: call dlclose() to unload libB.so |
| // linker: crazy::WrapDlClose() gets called. |
| // linker: run ELF finalizers in libB.so |
| // libB.so: call dlclose() to unload libC.so. |
| // linker: crazy::WrapDlClose() gets called. |
| // linker: unload libC.so (no finalizers). |
| // libB.so: return from finalizer. |
| // linker: libB.so has finished unloading. |
| // libA.so: return from finalizer. |
| // linker: libA.so has finished unloaded. |
| // exe: program continues and exits. |
| // |
| // Actual names for this test: |
| // libA.so: libcrazy_linker_tests_libzoo_dlopen_in_initializer.so |
| // libB.so: libcrazy_linker_tests_libzoo_dlopen_in_initializer_inner.so |
| // libC.so: libcrazy_linker_tests_libzoo.so |
| // libD.so: libcrazy_linker_tests_libbar.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. |
| FunctionPtr zoo_func; |
| if (!crazy_library_find_symbol(library, "Zoo", |
| reinterpret_cast<void**>(&zoo_func))) { |
| Panic("Could not find 'Zoo' in " LIB_NAME "\n"); |
| } |
| |
| // Call it |
| (*zoo_func)(); |
| |
| // Close the library. |
| printf("Closing " LIB_NAME "\n"); |
| crazy_library_close(library); |
| |
| crazy_context_destroy(context); |
| printf("OK\n"); |
| return 0; |
| } |