1 /*
2  * Copyright (C) 2012 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include <gtest/gtest.h>
18 
19 #if defined(__BIONIC__)
20 #include <android-base/properties.h>
21 #endif
22 
23 #include <dlfcn.h>
24 #include <libgen.h>
25 #include <limits.h>
26 #include <stdio.h>
27 #include <stdint.h>
28 #include <sys/stat.h>
29 
30 #include <fstream>
31 #include <iostream>
32 #include <regex>
33 #include <string>
34 
35 #include "gtest_globals.h"
36 #include <android-base/file.h>
37 #include "utils.h"
38 
main_global_default_serial()39 extern "C" int main_global_default_serial() {
40   return 3370318;
41 }
42 
main_global_protected_serial()43 extern "C" int main_global_protected_serial() {
44   return 2716057;
45 }
46 
47 // The following functions are defined in DT_NEEDED
48 // libdl_preempt_test.so library.
49 
50 // This one calls main_global_default_serial
51 extern "C" int main_global_default_get_serial();
52 
53 // This one calls main_global_protected_serial
54 extern "C" int main_global_protected_get_serial();
55 
56 // This one calls lib_global_default_serial
57 extern "C" int lib_global_default_get_serial();
58 
59 // This one calls lib_global_protected_serial
60 extern "C" int lib_global_protected_get_serial();
61 
62 // This test verifies that the global default function
63 // main_global_default_serial() is preempted by
64 // the function defined above.
TEST(dl,main_preempts_global_default)65 TEST(dl, main_preempts_global_default) {
66   ASSERT_EQ(3370318, main_global_default_get_serial());
67 }
68 
69 // This one makes sure that the global protected
70 // symbols do not get preempted
TEST(dl,main_does_not_preempt_global_protected)71 TEST(dl, main_does_not_preempt_global_protected) {
72   ASSERT_EQ(3370318, main_global_protected_get_serial());
73 }
74 
75 // check same things for lib
TEST(dl,lib_preempts_global_default)76 TEST(dl, lib_preempts_global_default) {
77   ASSERT_EQ(3370318, lib_global_default_get_serial());
78 }
79 
TEST(dl,lib_does_not_preempt_global_protected)80 TEST(dl, lib_does_not_preempt_global_protected) {
81   ASSERT_EQ(3370318, lib_global_protected_get_serial());
82 }
83 
84 #if defined(__BIONIC__)
85 #if defined(__LP64__)
86   static constexpr const char* kPathToLinker = "/system/bin/linker64";
87 #else
88   static constexpr const char* kPathToLinker = "/system/bin/linker";
89 #endif
90 
91 #if defined (__aarch64__)
92   static constexpr const char* kAlternatePathToLinker = "/system/bin/arm64/linker64";
93 #elif defined (__arm__)
94   static constexpr const char* kAlternatePathToLinker = "/system/bin/arm/linker";
95 #elif defined (__x86_64__)
96   static constexpr const char* kAlternatePathToLinker = "/system/bin/x86_64/linker64";
97 #elif defined (__i386__)
98   static constexpr const char* kAlternatePathToLinker = "/system/bin/x86/linker";
99 #else
100 #error "Unknown architecture"
101 #endif
102 
PathToLinker()103 const char* PathToLinker() {
104   // On the systems with emulated architecture linker would be of different
105   // architecture. Try to use alternate paths first.
106   struct stat buffer;
107   if (stat(kAlternatePathToLinker, &buffer) == 0) {
108     return kAlternatePathToLinker;
109   }
110   return kPathToLinker;
111 }
112 #endif  // defined(__BIONIC__)
113 
TEST(dl,exec_linker)114 TEST(dl, exec_linker) {
115 #if defined(__BIONIC__)
116   const char* path_to_linker = PathToLinker();
117   std::string usage_prefix = std::string("Usage: ") + path_to_linker;
118   ExecTestHelper eth;
119   eth.SetArgs({ path_to_linker, nullptr });
120   eth.Run([&]() { execve(path_to_linker, eth.GetArgs(), eth.GetEnv()); }, 0, nullptr);
121   ASSERT_EQ(0u, eth.GetOutput().find(usage_prefix)) << "Test output:\n" << eth.GetOutput();
122 #endif
123 }
124 
TEST(dl,exec_linker_load_file)125 TEST(dl, exec_linker_load_file) {
126 #if defined(__BIONIC__)
127   const char* path_to_linker = PathToLinker();
128   std::string helper = GetTestlibRoot() +
129       "/exec_linker_helper/exec_linker_helper";
130   std::string expected_output =
131       "ctor: argc=1 argv[0]=" + helper + "\n" +
132       "main: argc=1 argv[0]=" + helper + "\n" +
133       "__progname=exec_linker_helper\n" +
134       "helper_func called\n";
135   ExecTestHelper eth;
136   eth.SetArgs({ path_to_linker, helper.c_str(), nullptr });
137   eth.Run([&]() { execve(path_to_linker, eth.GetArgs(), eth.GetEnv()); }, 0, expected_output.c_str());
138 #endif
139 }
140 
TEST(dl,exec_linker_load_from_zip)141 TEST(dl, exec_linker_load_from_zip) {
142 #if defined(__BIONIC__)
143   const char* path_to_linker = PathToLinker();
144   std::string helper = GetTestlibRoot() +
145       "/libdlext_test_zip/libdlext_test_zip_zipaligned.zip!/libdir/exec_linker_helper";
146   std::string expected_output =
147       "ctor: argc=1 argv[0]=" + helper + "\n" +
148       "main: argc=1 argv[0]=" + helper + "\n" +
149       "__progname=exec_linker_helper\n" +
150       "helper_func called\n";
151   ExecTestHelper eth;
152   eth.SetArgs({ path_to_linker, helper.c_str(), nullptr });
153   eth.Run([&]() { execve(path_to_linker, eth.GetArgs(), eth.GetEnv()); }, 0, expected_output.c_str());
154 #endif
155 }
156 
TEST(dl,exec_linker_load_self)157 TEST(dl, exec_linker_load_self) {
158 #if defined(__BIONIC__)
159   const char* path_to_linker = PathToLinker();
160   std::string error_message = "error: linker cannot load itself\n";
161   ExecTestHelper eth;
162   eth.SetArgs({ path_to_linker, path_to_linker, nullptr });
163   eth.Run([&]() { execve(path_to_linker, eth.GetArgs(), eth.GetEnv()); }, EXIT_FAILURE, error_message.c_str());
164 #endif
165 }
166 
TEST(dl,preinit_system_calls)167 TEST(dl, preinit_system_calls) {
168 #if defined(__BIONIC__)
169   SKIP_WITH_HWASAN << "hwasan not initialized in preinit_array, b/124007027";
170   std::string helper = GetTestlibRoot() +
171       "/preinit_syscall_test_helper/preinit_syscall_test_helper";
172   chmod(helper.c_str(), 0755); // TODO: "x" lost in CTS, b/34945607
173   ExecTestHelper eth;
174   eth.SetArgs({ helper.c_str(), nullptr });
175   eth.Run([&]() { execve(helper.c_str(), eth.GetArgs(), eth.GetEnv()); }, 0, nullptr);
176 #endif
177 }
178 
TEST(dl,preinit_getauxval)179 TEST(dl, preinit_getauxval) {
180 #if defined(__BIONIC__)
181   SKIP_WITH_HWASAN << "hwasan not initialized in preinit_array, b/124007027";
182   std::string helper = GetTestlibRoot() +
183       "/preinit_getauxval_test_helper/preinit_getauxval_test_helper";
184   chmod(helper.c_str(), 0755); // TODO: "x" lost in CTS, b/34945607
185   ExecTestHelper eth;
186   eth.SetArgs({ helper.c_str(), nullptr });
187   eth.Run([&]() { execve(helper.c_str(), eth.GetArgs(), eth.GetEnv()); }, 0, nullptr);
188 #else
189   // Force a failure when not compiled for bionic so the test is considered a pass.
190   ASSERT_TRUE(false);
191 #endif
192 }
193 
194 
TEST(dl,exec_without_ld_preload)195 TEST(dl, exec_without_ld_preload) {
196 #if defined(__BIONIC__)
197   std::string helper = GetTestlibRoot() +
198       "/ld_preload_test_helper/ld_preload_test_helper";
199   chmod(helper.c_str(), 0755);
200   ExecTestHelper eth;
201   eth.SetArgs({ helper.c_str(), nullptr });
202   eth.Run([&]() { execve(helper.c_str(), eth.GetArgs(), eth.GetEnv()); }, 0, "12345");
203 #endif
204 }
205 
TEST(dl,exec_with_ld_preload)206 TEST(dl, exec_with_ld_preload) {
207 #if defined(__BIONIC__)
208   std::string helper = GetTestlibRoot() +
209       "/ld_preload_test_helper/ld_preload_test_helper";
210   std::string env = std::string("LD_PRELOAD=") + GetTestlibRoot() + "/ld_preload_test_helper_lib2.so";
211   chmod(helper.c_str(), 0755);
212   ExecTestHelper eth;
213   eth.SetArgs({ helper.c_str(), nullptr });
214   eth.SetEnv({ env.c_str(), nullptr });
215   // ld_preload_test_helper calls get_value_from_lib() and returns the value.
216   // The symbol is defined by two libs: ld_preload_test_helper_lib.so and
217   // ld_preloaded_lib.so. The former is DT_NEEDED and the latter is LD_PRELOADED
218   // via this execution. The main executable is linked to the LD_PRELOADED lib
219   // and the value given from the lib is returned.
220   eth.Run([&]() { execve(helper.c_str(), eth.GetArgs(), eth.GetEnv()); }, 0, "54321");
221 #endif
222 }
223 
224 
225 // ld_config_test_helper must fail because it is depending on a lib which is not
226 // in the search path
227 //
228 // Call sequence is...
229 // _helper -- (get_value_from_lib()) -->
230 //     _lib1.so -- (get_value_from_another_lib()) -->
231 //       _lib2.so (returns 12345)
232 // The two libs are in ns2/ subdir.
TEST(dl,exec_without_ld_config_file)233 TEST(dl, exec_without_ld_config_file) {
234 #if defined(__BIONIC__)
235   std::string error_message =
236       "CANNOT LINK EXECUTABLE \"" + GetTestlibRoot() +
237       "/ld_config_test_helper/ld_config_test_helper\": library \"ld_config_test_helper_lib1.so\" "
238       "not found: needed by main executable\n";
239   std::string helper = GetTestlibRoot() +
240       "/ld_config_test_helper/ld_config_test_helper";
241   chmod(helper.c_str(), 0755);
242   ExecTestHelper eth;
243   eth.SetArgs({ helper.c_str(), nullptr });
244   eth.Run([&]() { execve(helper.c_str(), eth.GetArgs(), eth.GetEnv()); }, EXIT_FAILURE, error_message.c_str());
245 #endif
246 }
247 
248 #if defined(__BIONIC__)
249 extern "C" void android_get_LD_LIBRARY_PATH(char*, size_t);
create_ld_config_file(const char * config_file)250 static void create_ld_config_file(const char* config_file) {
251   char default_search_paths[PATH_MAX];
252   android_get_LD_LIBRARY_PATH(default_search_paths, sizeof(default_search_paths));
253 
254   std::ofstream fout(config_file, std::ios::out);
255   fout << "dir.test = " << GetTestlibRoot() << "/ld_config_test_helper/" << std::endl
256        << "[test]" << std::endl
257        << "additional.namespaces = ns2" << std::endl
258        << "namespace.default.search.paths = " << GetTestlibRoot() << std::endl
259        << "namespace.default.links = ns2" << std::endl
260        << "namespace.default.link.ns2.shared_libs = libc.so:libm.so:libdl.so:ld_config_test_helper_lib1.so" << std::endl
261        << "namespace.ns2.search.paths = " << default_search_paths << ":" << GetTestlibRoot() << "/ns2" << std::endl;
262   fout.close();
263 }
264 #endif
265 
266 #if defined(__BIONIC__)
267 // This test can't rely on ro.debuggable, because it might have been forced on
268 // in a user build ("Force Debuggable"). In that configuration, ro.debuggable is
269 // true, but Bionic's LD_CONFIG_FILE testing support is still disabled.
is_user_build()270 static bool is_user_build() {
271   return android::base::GetProperty("ro.build.type", "user") == std::string("user");
272 }
273 #endif
274 
275 // lib1.so and lib2.so are now searchable by having another namespace 'ns2'
276 // whose search paths include the 'ns2/' subdir.
277 //
278 // lib1.so is linked with DF_1_GLOBAL, so both it and the executable are added
279 // to every namespace.
280 //
281 // namespace configuration ('*' indicates primary ns)
282 //  - default: exe[*], lib1.so
283 //  - ns2: exe, lib1.so[*], lib2.so[*]
284 //
TEST(dl,exec_with_ld_config_file)285 TEST(dl, exec_with_ld_config_file) {
286 #if defined(__BIONIC__)
287   SKIP_WITH_HWASAN << "libclang_rt.hwasan is not found with custom ld config";
288   if (is_user_build()) {
289     GTEST_SKIP() << "LD_CONFIG_FILE is not supported on user build";
290   }
291   std::string helper = GetTestlibRoot() +
292       "/ld_config_test_helper/ld_config_test_helper";
293   TemporaryFile config_file;
294   create_ld_config_file(config_file.path);
295   std::string env = std::string("LD_CONFIG_FILE=") + config_file.path;
296   chmod(helper.c_str(), 0755);
297   ExecTestHelper eth;
298   eth.SetArgs({ helper.c_str(), nullptr });
299   eth.SetEnv({ env.c_str(), nullptr });
300   eth.Run([&]() { execve(helper.c_str(), eth.GetArgs(), eth.GetEnv()); }, 0,
301           "foo lib1\n"
302           "lib1_call_funcs\n"
303           "foo lib1\n"
304           "bar lib2\n");
305 #endif
306 }
307 
308 // lib3.so has same foo and bar symbols as lib2.so. lib3.so is LD_PRELOADed.
309 // This test ensures that LD_PRELOADed libs are available to all namespaces.
310 //
311 // namespace configuration ('*' indicates primary ns)
312 //  - default: exe[*], lib3.so[*], lib1.so
313 //  - ns2: exe, lib3.so, lib1.so[*], lib2.so[*]
314 //
315 // Ensure that, in both namespaces, a call to foo calls the lib3.so symbol,
316 // which then calls the lib1.so symbol using RTLD_NEXT. Ensure that RTLD_NEXT
317 // finds nothing when called from lib1.so.
318 //
319 // For the bar symbol, lib3.so's primary namespace is the default namespace, but
320 // lib2.so is not in the default namespace, so using RTLD_NEXT from lib3.so
321 // doesn't find the symbol in lib2.so.
TEST(dl,exec_with_ld_config_file_with_ld_preload)322 TEST(dl, exec_with_ld_config_file_with_ld_preload) {
323 #if defined(__BIONIC__)
324   SKIP_WITH_HWASAN << "libclang_rt.hwasan is not found with custom ld config";
325   if (is_user_build()) {
326     GTEST_SKIP() << "LD_CONFIG_FILE is not supported on user build";
327   }
328   std::string helper = GetTestlibRoot() +
329       "/ld_config_test_helper/ld_config_test_helper";
330   TemporaryFile config_file;
331   create_ld_config_file(config_file.path);
332   std::string env = std::string("LD_CONFIG_FILE=") + config_file.path;
333   std::string env2 = std::string("LD_PRELOAD=") + GetTestlibRoot() + "/ld_config_test_helper_lib3.so";
334   chmod(helper.c_str(), 0755);
335   ExecTestHelper eth;
336   eth.SetArgs({ helper.c_str(), nullptr });
337   eth.SetEnv({ env.c_str(), env2.c_str(), nullptr });
338   eth.Run([&]() { execve(helper.c_str(), eth.GetArgs(), eth.GetEnv()); }, 0,
339           "foo lib3\n"
340           "foo lib1\n"
341           "lib1_call_funcs\n"
342           "foo lib3\n"
343           "foo lib1\n"
344           "bar lib3\n"
345           "lib3_call_funcs\n"
346           "foo lib3\n"
347           "foo lib1\n"
348           "bar lib3\n");
349 #endif
350 }
351 
352 // ensures that LD_CONFIG_FILE env var does not work for production builds.
353 // The test input is the same as exec_with_ld_config_file, but it must fail in
354 // this case.
TEST(dl,disable_ld_config_file)355 TEST(dl, disable_ld_config_file) {
356 #if defined(__BIONIC__)
357   if (getuid() == 0) {
358     // when executed from the shell (e.g. not as part of CTS), skip the test.
359     // This test is only for CTS.
360     GTEST_SKIP() << "test is not supported with root uid";
361   }
362   if (!is_user_build()) {
363     GTEST_SKIP() << "test requires user build";
364   }
365 
366   std::string error_message = std::string("CANNOT LINK EXECUTABLE ") +
367       "\"" + GetTestlibRoot() + "/ld_config_test_helper/ld_config_test_helper\": " +
368       "library \"ld_config_test_helper_lib1.so\" not found: needed by main executable\n";
369   std::string helper = GetTestlibRoot() +
370       "/ld_config_test_helper/ld_config_test_helper";
371   TemporaryFile config_file;
372   create_ld_config_file(config_file.path);
373   std::string env = std::string("LD_CONFIG_FILE=") + config_file.path;
374   chmod(helper.c_str(), 0755);
375   ExecTestHelper eth;
376   eth.SetArgs({ helper.c_str(), nullptr });
377   eth.SetEnv({ env.c_str(), nullptr });
378   eth.Run([&]() { execve(helper.c_str(), eth.GetArgs(), eth.GetEnv()); }, EXIT_FAILURE, error_message.c_str());
379 #endif
380 }
381 
RelocationsTest(const char * lib,const char * expectation)382 static void RelocationsTest(const char* lib, const char* expectation) {
383 #if defined(__BIONIC__)
384   // Does readelf think the .so file looks right?
385   const std::string path = GetTestlibRoot() + "/" + lib;
386   ExecTestHelper eth;
387   eth.SetArgs({ "readelf", "-SW", path.c_str(), nullptr });
388   eth.Run([&]() { execvpe("readelf", eth.GetArgs(), eth.GetEnv()); }, 0, nullptr);
389 
390   ASSERT_TRUE(std::regex_search(eth.GetOutput(), std::regex(expectation))) << eth.GetOutput();
391 
392   // Can we load it?
393   void* handle = dlopen(lib, RTLD_NOW);
394   ASSERT_TRUE(handle != nullptr) << dlerror();
395 #else
396   UNUSED(lib);
397   UNUSED(expectation);
398   GTEST_SKIP() << "test is not supported on glibc";
399 #endif
400 }
401 
TEST(dl,relocations_RELR)402 TEST(dl, relocations_RELR) {
403   RelocationsTest("librelocations-RELR.so", "\\.relr\\.dyn * RELR");
404 }
405 
TEST(dl,relocations_ANDROID_RELR)406 TEST(dl, relocations_ANDROID_RELR) {
407   RelocationsTest("librelocations-ANDROID_RELR.so", "\\.relr\\.dyn * ANDROID_RELR");
408 }
409 
TEST(dl,relocations_ANDROID_REL)410 TEST(dl, relocations_ANDROID_REL) {
411   RelocationsTest("librelocations-ANDROID_REL.so",
412 #if __LP64__
413                   "\\.rela\\.dyn * ANDROID_RELA"
414 #else
415                   "\\.rel\\.dyn * ANDROID_REL"
416 #endif
417   );
418 }
419 
TEST(dl,relocations_fat)420 TEST(dl, relocations_fat) {
421   RelocationsTest("librelocations-fat.so",
422 #if __LP64__
423                   "\\.rela\\.dyn * RELA"
424 #else
425                   "\\.rel\\.dyn * REL"
426 #endif
427   );
428 }
429