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 #include <dlfcn.h>
20 #include <libgen.h>
21 #include <limits.h>
22 #include <stdio.h>
23 #include <stdint.h>
24 
25 #include "private/ScopeGuard.h"
26 
27 #include <string>
28 
29 #include "utils.h"
30 
31 #define ASSERT_SUBSTR(needle, haystack) \
32     ASSERT_PRED_FORMAT2(::testing::IsSubstring, needle, haystack)
33 
34 
35 static bool g_called = false;
DlSymTestFunction()36 extern "C" void DlSymTestFunction() {
37   g_called = true;
38 }
39 
40 static int g_ctor_function_called = 0;
41 
42 extern "C" void ctor_function() __attribute__ ((constructor));
43 
ctor_function()44 extern "C" void ctor_function() {
45   g_ctor_function_called = 17;
46 }
47 
TEST(dlfcn,ctor_function_call)48 TEST(dlfcn, ctor_function_call) {
49   ASSERT_EQ(17, g_ctor_function_called);
50 }
51 
TEST(dlfcn,dlsym_in_executable)52 TEST(dlfcn, dlsym_in_executable) {
53   dlerror(); // Clear any pending errors.
54   void* self = dlopen(nullptr, RTLD_NOW);
55   ASSERT_TRUE(self != nullptr);
56   ASSERT_TRUE(dlerror() == nullptr);
57 
58   void* sym = dlsym(self, "DlSymTestFunction");
59   ASSERT_TRUE(sym != nullptr);
60 
61   void (*function)() = reinterpret_cast<void(*)()>(sym);
62 
63   g_called = false;
64   function();
65   ASSERT_TRUE(g_called);
66 
67   ASSERT_EQ(0, dlclose(self));
68 }
69 
TEST(dlfcn,dlsym_from_sofile)70 TEST(dlfcn, dlsym_from_sofile) {
71   void* handle = dlopen("libtest_dlsym_from_this.so", RTLD_LAZY | RTLD_LOCAL);
72   ASSERT_TRUE(handle != nullptr) << dlerror();
73 
74   // check that we can't find '_test_dlsym_symbol' via dlsym(RTLD_DEFAULT)
75   void* symbol = dlsym(RTLD_DEFAULT, "test_dlsym_symbol");
76   ASSERT_TRUE(symbol == nullptr);
77   ASSERT_SUBSTR("undefined symbol: test_dlsym_symbol", dlerror());
78 
79   typedef int* (*fn_t)();
80   fn_t lookup_dlsym_symbol_using_RTLD_DEFAULT =
81       reinterpret_cast<fn_t>(dlsym(handle, "lookup_dlsym_symbol_using_RTLD_DEFAULT"));
82   ASSERT_TRUE(lookup_dlsym_symbol_using_RTLD_DEFAULT != nullptr) << dlerror();
83 
84   int* ptr = lookup_dlsym_symbol_using_RTLD_DEFAULT();
85   ASSERT_TRUE(ptr != nullptr) << dlerror();
86   ASSERT_EQ(42, *ptr);
87 
88   fn_t lookup_dlsym_symbol2_using_RTLD_DEFAULT =
89       reinterpret_cast<fn_t>(dlsym(handle, "lookup_dlsym_symbol2_using_RTLD_DEFAULT"));
90   ASSERT_TRUE(lookup_dlsym_symbol2_using_RTLD_DEFAULT != nullptr) << dlerror();
91 
92   ptr = lookup_dlsym_symbol2_using_RTLD_DEFAULT();
93   ASSERT_TRUE(ptr != nullptr) << dlerror();
94   ASSERT_EQ(44, *ptr);
95 
96   fn_t lookup_dlsym_symbol_using_RTLD_NEXT =
97       reinterpret_cast<fn_t>(dlsym(handle, "lookup_dlsym_symbol_using_RTLD_NEXT"));
98   ASSERT_TRUE(lookup_dlsym_symbol_using_RTLD_NEXT != nullptr) << dlerror();
99 
100   ptr = lookup_dlsym_symbol_using_RTLD_NEXT();
101   ASSERT_TRUE(ptr != nullptr) << dlerror();
102   ASSERT_EQ(43, *ptr);
103 
104   dlclose(handle);
105 }
106 
TEST(dlfcn,dlsym_from_sofile_with_preload)107 TEST(dlfcn, dlsym_from_sofile_with_preload) {
108   void* preload = dlopen("libtest_dlsym_from_this_grandchild.so", RTLD_NOW | RTLD_LOCAL);
109   ASSERT_TRUE(preload != nullptr) << dlerror();
110 
111   void* handle = dlopen("libtest_dlsym_from_this.so", RTLD_NOW | RTLD_LOCAL);
112   ASSERT_TRUE(handle != nullptr) << dlerror();
113 
114   // check that we can't find '_test_dlsym_symbol' via dlsym(RTLD_DEFAULT)
115   void* symbol = dlsym(RTLD_DEFAULT, "test_dlsym_symbol");
116   ASSERT_TRUE(symbol == nullptr);
117   ASSERT_SUBSTR("undefined symbol: test_dlsym_symbol", dlerror());
118 
119   typedef int* (*fn_t)();
120   fn_t lookup_dlsym_symbol_using_RTLD_DEFAULT =
121       reinterpret_cast<fn_t>(dlsym(handle, "lookup_dlsym_symbol_using_RTLD_DEFAULT"));
122   ASSERT_TRUE(lookup_dlsym_symbol_using_RTLD_DEFAULT != nullptr) << dlerror();
123 
124   int* ptr = lookup_dlsym_symbol_using_RTLD_DEFAULT();
125   ASSERT_TRUE(ptr != nullptr) << dlerror();
126   ASSERT_EQ(42, *ptr);
127 
128   fn_t lookup_dlsym_symbol2_using_RTLD_DEFAULT =
129       reinterpret_cast<fn_t>(dlsym(handle, "lookup_dlsym_symbol2_using_RTLD_DEFAULT"));
130   ASSERT_TRUE(lookup_dlsym_symbol2_using_RTLD_DEFAULT != nullptr) << dlerror();
131 
132   ptr = lookup_dlsym_symbol2_using_RTLD_DEFAULT();
133   ASSERT_TRUE(ptr != nullptr) << dlerror();
134   ASSERT_EQ(44, *ptr);
135 
136   fn_t lookup_dlsym_symbol_using_RTLD_NEXT =
137       reinterpret_cast<fn_t>(dlsym(handle, "lookup_dlsym_symbol_using_RTLD_NEXT"));
138   ASSERT_TRUE(lookup_dlsym_symbol_using_RTLD_NEXT != nullptr) << dlerror();
139 
140   ptr = lookup_dlsym_symbol_using_RTLD_NEXT();
141   ASSERT_TRUE(ptr != nullptr) << dlerror();
142   ASSERT_EQ(43, *ptr);
143 
144   dlclose(handle);
145   dlclose(preload);
146 }
147 
TEST(dlfcn,dlsym_handle_global_sym)148 TEST(dlfcn, dlsym_handle_global_sym) {
149   // check that we do not look into global group
150   // when looking up symbol by handle
151   void* handle = dlopen("libtest_empty.so", RTLD_NOW);
152   dlopen("libtest_with_dependency.so", RTLD_NOW | RTLD_GLOBAL);
153   void* sym = dlsym(handle, "getRandomNumber");
154   ASSERT_TRUE(sym == nullptr);
155   ASSERT_SUBSTR("undefined symbol: getRandomNumber", dlerror());
156 
157   sym = dlsym(handle, "DlSymTestFunction");
158   ASSERT_TRUE(sym == nullptr);
159   ASSERT_SUBSTR("undefined symbol: DlSymTestFunction", dlerror());
160   dlclose(handle);
161 }
162 
TEST(dlfcn,dlsym_with_dependencies)163 TEST(dlfcn, dlsym_with_dependencies) {
164   void* handle = dlopen("libtest_with_dependency.so", RTLD_NOW);
165   ASSERT_TRUE(handle != nullptr);
166   dlerror();
167   // This symbol is in DT_NEEDED library.
168   void* sym = dlsym(handle, "getRandomNumber");
169   ASSERT_TRUE(sym != nullptr) << dlerror();
170   int (*fn)(void);
171   fn = reinterpret_cast<int (*)(void)>(sym);
172   EXPECT_EQ(4, fn());
173   dlclose(handle);
174 }
175 
TEST(dlfcn,dlopen_noload)176 TEST(dlfcn, dlopen_noload) {
177   void* handle = dlopen("libtest_simple.so", RTLD_NOW | RTLD_NOLOAD);
178   ASSERT_TRUE(handle == nullptr);
179   handle = dlopen("libtest_simple.so", RTLD_NOW);
180   void* handle2 = dlopen("libtest_simple.so", RTLD_NOW | RTLD_NOLOAD);
181   ASSERT_TRUE(handle != nullptr);
182   ASSERT_TRUE(handle2 != nullptr);
183   ASSERT_TRUE(handle == handle2);
184   ASSERT_EQ(0, dlclose(handle));
185   ASSERT_EQ(0, dlclose(handle2));
186 }
187 
TEST(dlfcn,dlopen_by_soname)188 TEST(dlfcn, dlopen_by_soname) {
189   static const char* soname = "libdlext_test_soname.so";
190   static const char* filename = "libdlext_test_different_soname.so";
191   // 1. Make sure there is no library with soname in default search path
192   void* handle = dlopen(soname, RTLD_NOW);
193   ASSERT_TRUE(handle == nullptr);
194 
195   // 2. Load a library using filename
196   handle = dlopen(filename, RTLD_NOW);
197   ASSERT_TRUE(handle != nullptr) << dlerror();
198 
199   // 3. Find library by soname
200   void* handle_soname = dlopen(soname, RTLD_NOW | RTLD_NOLOAD);
201   ASSERT_TRUE(handle_soname != nullptr) << dlerror();
202   ASSERT_EQ(handle, handle_soname);
203 
204   // 4. RTLD_NOLOAD should still work with filename
205   void* handle_filename = dlopen(filename, RTLD_NOW | RTLD_NOLOAD);
206   ASSERT_TRUE(handle_filename != nullptr) << dlerror();
207   ASSERT_EQ(handle, handle_filename);
208 
209   dlclose(handle_filename);
210   dlclose(handle_soname);
211   dlclose(handle);
212 }
213 
214 // ifuncs are only supported on intel and arm64 for now
215 #if defined (__aarch64__) || defined(__i386__) || defined(__x86_64__)
TEST(dlfcn,ifunc)216 TEST(dlfcn, ifunc) {
217   typedef const char* (*fn_ptr)();
218 
219   // ifunc's choice depends on whether IFUNC_CHOICE has a value
220   // first check the set case
221   setenv("IFUNC_CHOICE", "set", 1);
222   void* handle = dlopen("libtest_ifunc.so", RTLD_NOW);
223   ASSERT_TRUE(handle != nullptr);
224   fn_ptr foo_ptr = reinterpret_cast<fn_ptr>(dlsym(handle, "foo"));
225   fn_ptr foo_library_ptr = reinterpret_cast<fn_ptr>(dlsym(handle, "foo_library"));
226   ASSERT_TRUE(foo_ptr != nullptr);
227   ASSERT_TRUE(foo_library_ptr != nullptr);
228   ASSERT_EQ(strncmp("set", foo_ptr(), 3), 0);
229   ASSERT_EQ(strncmp("set", foo_library_ptr(), 3), 0);
230   dlclose(handle);
231 
232   // then check the unset case
233   unsetenv("IFUNC_CHOICE");
234   handle = dlopen("libtest_ifunc.so", RTLD_NOW);
235   ASSERT_TRUE(handle != nullptr);
236   foo_ptr = reinterpret_cast<fn_ptr>(dlsym(handle, "foo"));
237   foo_library_ptr = reinterpret_cast<fn_ptr>(dlsym(handle, "foo_library"));
238   ASSERT_TRUE(foo_ptr != nullptr);
239   ASSERT_TRUE(foo_library_ptr != nullptr);
240   ASSERT_EQ(strncmp("unset", foo_ptr(), 5), 0);
241   ASSERT_EQ(strncmp("unset", foo_library_ptr(), 3), 0);
242   dlclose(handle);
243 }
244 
TEST(dlfcn,ifunc_ctor_call)245 TEST(dlfcn, ifunc_ctor_call) {
246   typedef const char* (*fn_ptr)();
247 
248   void* handle = dlopen("libtest_ifunc.so", RTLD_NOW);
249   ASSERT_TRUE(handle != nullptr) << dlerror();
250   fn_ptr is_ctor_called =  reinterpret_cast<fn_ptr>(dlsym(handle, "is_ctor_called_irelative"));
251   ASSERT_TRUE(is_ctor_called != nullptr) << dlerror();
252   ASSERT_STREQ("false", is_ctor_called());
253 
254   is_ctor_called =  reinterpret_cast<fn_ptr>(dlsym(handle, "is_ctor_called_jump_slot"));
255   ASSERT_TRUE(is_ctor_called != nullptr) << dlerror();
256   ASSERT_STREQ("true", is_ctor_called());
257   dlclose(handle);
258 }
259 #endif
260 
TEST(dlfcn,dlopen_check_relocation_dt_needed_order)261 TEST(dlfcn, dlopen_check_relocation_dt_needed_order) {
262   // This is the structure of the test library and
263   // its dt_needed libraries
264   // libtest_relo_check_dt_needed_order.so
265   // |
266   // +-> libtest_relo_check_dt_needed_order_1.so
267   // |
268   // +-> libtest_relo_check_dt_needed_order_2.so
269   //
270   // The root library references relo_test_get_answer_lib - which is defined
271   // in both dt_needed libraries, the correct relocation should
272   // use the function defined in libtest_relo_check_dt_needed_order_1.so
273   void* handle = nullptr;
274   auto guard = make_scope_guard([&]() {
275     dlclose(handle);
276   });
277 
278   handle = dlopen("libtest_relo_check_dt_needed_order.so", RTLD_NOW);
279   ASSERT_TRUE(handle != nullptr) << dlerror();
280 
281   typedef int (*fn_t) (void);
282   fn_t fn = reinterpret_cast<fn_t>(dlsym(handle, "relo_test_get_answer"));
283   ASSERT_TRUE(fn != nullptr) << dlerror();
284   ASSERT_EQ(1, fn());
285 }
286 
TEST(dlfcn,dlopen_check_order_dlsym)287 TEST(dlfcn, dlopen_check_order_dlsym) {
288   // Here is how the test library and its dt_needed
289   // libraries are arranged
290   //
291   //  libtest_check_order_children.so
292   //  |
293   //  +-> ..._1_left.so
294   //  |   |
295   //  |   +-> ..._a.so
296   //  |   |
297   //  |   +-> ...r_b.so
298   //  |
299   //  +-> ..._2_right.so
300   //  |   |
301   //  |   +-> ..._d.so
302   //  |       |
303   //  |       +-> ..._b.so
304   //  |
305   //  +-> ..._3_c.so
306   //
307   //  load order should be (1, 2, 3, a, b, d)
308   //
309   // get_answer() is defined in (2, 3, a, b, c)
310   // get_answer2() is defined in (b, d)
311   void* sym = dlsym(RTLD_DEFAULT, "check_order_dlsym_get_answer");
312   ASSERT_TRUE(sym == nullptr);
313   void* handle = dlopen("libtest_check_order_dlsym.so", RTLD_NOW | RTLD_GLOBAL);
314   ASSERT_TRUE(handle != nullptr) << dlerror();
315   typedef int (*fn_t) (void);
316   fn_t fn, fn2;
317   fn = reinterpret_cast<fn_t>(dlsym(RTLD_DEFAULT, "check_order_dlsym_get_answer"));
318   ASSERT_TRUE(fn != nullptr) << dlerror();
319   fn2 = reinterpret_cast<fn_t>(dlsym(RTLD_DEFAULT, "check_order_dlsym_get_answer2"));
320   ASSERT_TRUE(fn2 != nullptr) << dlerror();
321 
322   ASSERT_EQ(42, fn());
323   ASSERT_EQ(43, fn2());
324   dlclose(handle);
325 }
326 
TEST(dlfcn,dlopen_check_order_reloc_siblings)327 TEST(dlfcn, dlopen_check_order_reloc_siblings) {
328   // This is how this one works:
329   // we lookup and call get_answer which is defined in '_2.so'
330   // and in turn calls external get_answer_impl() defined in _1.so and in '_[a-f].so'
331   // the correct _impl() is implemented by '_a.so';
332   //
333   // Note that this is test for RTLD_LOCAL (TODO: test for GLOBAL?)
334   //
335   // Here is the picture:
336   //
337   // libtest_check_order_reloc_siblings.so
338   // |
339   // +-> ..._1.so <- empty
340   // |   |
341   // |   +-> ..._a.so <- exports correct answer_impl()
342   // |   |
343   // |   +-> ..._b.so <- every other letter exporting incorrect one.
344   // |
345   // +-> ..._2.so <- empty
346   // |   |
347   // |   +-> ..._c.so
348   // |   |
349   // |   +-> ..._d.so
350   // |
351   // +-> ..._3.so <- empty
352   //     |
353   //     +-> ..._e.so
354   //     |
355   //     +-> ..._f.so <- exports get_answer() that calls get_anser_impl();
356   //                     implements incorrect get_answer_impl()
357 
358   void* handle = dlopen("libtest_check_order_reloc_siblings.so", RTLD_NOW | RTLD_NOLOAD);
359   ASSERT_TRUE(handle == nullptr);
360 #ifdef __BIONIC__
361   // TODO: glibc returns nullptr on dlerror() here. Is it bug?
362   ASSERT_STREQ("dlopen failed: library \"libtest_check_order_reloc_siblings.so\" wasn't loaded and RTLD_NOLOAD prevented it", dlerror());
363 #endif
364 
365   handle = dlopen("libtest_check_order_reloc_siblings.so", RTLD_NOW | RTLD_LOCAL);
366   ASSERT_TRUE(handle != nullptr) << dlerror();
367 
368   typedef int (*fn_t) (void);
369   fn_t fn = reinterpret_cast<fn_t>(dlsym(handle, "check_order_reloc_get_answer"));
370   ASSERT_TRUE(fn != nullptr) << dlerror();
371   ASSERT_EQ(42, fn());
372 
373   ASSERT_EQ(0, dlclose(handle));
374 }
375 
TEST(dlfcn,dlopen_check_order_reloc_siblings_with_preload)376 TEST(dlfcn, dlopen_check_order_reloc_siblings_with_preload) {
377   // This test uses the same library as dlopen_check_order_reloc_siblings.
378   // Unlike dlopen_check_order_reloc_siblings it preloads
379   // libtest_check_order_reloc_siblings_1.so (first dependency) prior to
380   // dlopen(libtest_check_order_reloc_siblings.so)
381 
382   void* handle = dlopen("libtest_check_order_reloc_siblings.so", RTLD_NOW | RTLD_NOLOAD);
383   ASSERT_TRUE(handle == nullptr);
384   handle = dlopen("libtest_check_order_reloc_siblings_1.so", RTLD_NOW | RTLD_NOLOAD);
385   ASSERT_TRUE(handle == nullptr);
386 
387   void* handle_for_1 = dlopen("libtest_check_order_reloc_siblings_1.so", RTLD_NOW | RTLD_LOCAL);
388   ASSERT_TRUE(handle_for_1 != nullptr) << dlerror();
389 
390   handle = dlopen("libtest_check_order_reloc_siblings.so", RTLD_NOW | RTLD_LOCAL);
391   ASSERT_TRUE(handle != nullptr) << dlerror();
392 
393   ASSERT_EQ(0, dlclose(handle_for_1));
394 
395   typedef int (*fn_t) (void);
396   fn_t fn = reinterpret_cast<fn_t>(dlsym(handle, "check_order_reloc_get_answer"));
397   ASSERT_TRUE(fn != nullptr) << dlerror();
398   ASSERT_EQ(42, fn());
399 
400   ASSERT_EQ(0, dlclose(handle));
401 }
402 
TEST(dlfcn,dlopen_check_order_reloc_grandchild)403 TEST(dlfcn, dlopen_check_order_reloc_grandchild) {
404   // This is how this one works:
405   // we lookup and call grandchild_get_answer which is defined in '_2.so'
406   // and in turn calls external get_answer_impl() defined in '_c_1.so and _c_2.so'
407   // the correct _impl() is implemented by '_c_1.so';
408   //
409   // Here is the picture of subtree:
410   //
411   // libtest_check_order_reloc_siblings.so
412   // |
413   // +-> ..._2.so <- grandchild_get_answer()
414   //     |
415   //     +-> ..._c.so <- empty
416   //     |   |
417   //     |   +-> _c_1.so <- exports correct answer_impl()
418   //     |   |
419   //     |   +-> _c_2.so <- exports incorrect answer_impl()
420   //     |
421   //     +-> ..._d.so <- empty
422 
423   void* handle = dlopen("libtest_check_order_reloc_siblings.so", RTLD_NOW | RTLD_NOLOAD);
424   ASSERT_TRUE(handle == nullptr);
425 #ifdef __BIONIC__
426   // TODO: glibc returns nullptr on dlerror() here. Is it bug?
427   ASSERT_STREQ("dlopen failed: library \"libtest_check_order_reloc_siblings.so\" wasn't loaded and RTLD_NOLOAD prevented it", dlerror());
428 #endif
429 
430   handle = dlopen("libtest_check_order_reloc_siblings.so", RTLD_NOW | RTLD_LOCAL);
431   ASSERT_TRUE(handle != nullptr) << dlerror();
432 
433   typedef int (*fn_t) (void);
434   fn_t fn = reinterpret_cast<fn_t>(dlsym(handle, "check_order_reloc_grandchild_get_answer"));
435   ASSERT_TRUE(fn != nullptr) << dlerror();
436   ASSERT_EQ(42, fn());
437 
438   ASSERT_EQ(0, dlclose(handle));
439 }
440 
TEST(dlfcn,dlopen_check_order_reloc_nephew)441 TEST(dlfcn, dlopen_check_order_reloc_nephew) {
442   // This is how this one works:
443   // we lookup and call nephew_get_answer which is defined in '_2.so'
444   // and in turn calls external get_answer_impl() defined in '_[a-f].so'
445   // the correct _impl() is implemented by '_a.so';
446   //
447   // Here is the picture:
448   //
449   // libtest_check_order_reloc_siblings.so
450   // |
451   // +-> ..._1.so <- empty
452   // |   |
453   // |   +-> ..._a.so <- exports correct answer_impl()
454   // |   |
455   // |   +-> ..._b.so <- every other letter exporting incorrect one.
456   // |
457   // +-> ..._2.so <- empty
458   // |   |
459   // |   +-> ..._c.so
460   // |   |
461   // |   +-> ..._d.so
462   // |
463   // +-> ..._3.so <- nephew_get_answer() that calls get_answer_impl();
464   //     |
465   //     +-> ..._e.so
466   //     |
467   //     +-> ..._f.so
468 
469   void* handle = dlopen("libtest_check_order_reloc_siblings.so", RTLD_NOW | RTLD_NOLOAD);
470   ASSERT_TRUE(handle == nullptr);
471 #ifdef __BIONIC__
472   // TODO: glibc returns nullptr on dlerror() here. Is it bug?
473   ASSERT_STREQ("dlopen failed: library \"libtest_check_order_reloc_siblings.so\" wasn't loaded and RTLD_NOLOAD prevented it", dlerror());
474 #endif
475 
476   handle = dlopen("libtest_check_order_reloc_siblings.so", RTLD_NOW | RTLD_LOCAL);
477   ASSERT_TRUE(handle != nullptr) << dlerror();
478 
479   typedef int (*fn_t) (void);
480   fn_t fn = reinterpret_cast<fn_t>(dlsym(handle, "check_order_reloc_nephew_get_answer"));
481   ASSERT_TRUE(fn != nullptr) << dlerror();
482   ASSERT_EQ(42, fn());
483 
484   ASSERT_EQ(0, dlclose(handle));
485 }
486 
TEST(dlfcn,check_unload_after_reloc)487 TEST(dlfcn, check_unload_after_reloc) {
488   // This is how this one works:
489   // libtest_two_parents_parent1 <- answer_impl() used by libtest_two_parents_child
490   // |
491   // +-> libtest_two_parents_child
492   //
493   // libtest_two_parents_parent2 <- answer_impl() not used by libtest_two_parents_child
494   // |
495   // +-> libtest_two_parents_child
496   //
497   // Test dlopens parent1 which loads and relocates libtest_two_parents_child.so
498   // as a second step it dlopens parent2 and dlcloses parent1...
499 
500   void* handle = dlopen("libtest_two_parents_parent1.so", RTLD_NOW | RTLD_LOCAL);
501   ASSERT_TRUE(handle != nullptr) << dlerror();
502 
503   void* handle2 = dlopen("libtest_two_parents_parent2.so", RTLD_NOW | RTLD_LOCAL);
504   ASSERT_TRUE(handle2 != nullptr) << dlerror();
505 
506   typedef int (*fn_t) (void);
507   fn_t fn = reinterpret_cast<fn_t>(dlsym(handle2, "check_order_reloc_get_answer"));
508   ASSERT_TRUE(fn != nullptr) << dlerror();
509   ASSERT_EQ(42, fn());
510 
511   ASSERT_EQ(0, dlclose(handle));
512 
513   handle = dlopen("libtest_two_parents_parent1.so", RTLD_NOW | RTLD_LOCAL | RTLD_NOLOAD);
514   ASSERT_TRUE(handle != nullptr);
515   ASSERT_EQ(0, dlclose(handle));
516 
517   fn = reinterpret_cast<fn_t>(dlsym(handle2, "check_order_reloc_get_answer"));
518   ASSERT_TRUE(fn != nullptr) << dlerror();
519   ASSERT_EQ(42, fn());
520 
521   ASSERT_EQ(0, dlclose(handle2));
522 
523   handle = dlopen("libtest_two_parents_parent1.so", RTLD_NOW | RTLD_LOCAL | RTLD_NOLOAD);
524   ASSERT_TRUE(handle == nullptr);
525 }
526 
check_order_reloc_root_get_answer_impl()527 extern "C" int check_order_reloc_root_get_answer_impl() {
528   return 42;
529 }
530 
TEST(dlfcn,dlopen_check_order_reloc_main_executable)531 TEST(dlfcn, dlopen_check_order_reloc_main_executable) {
532   // This is how this one works:
533   // we lookup and call get_answer3 which is defined in 'root.so'
534   // and in turn calls external root_get_answer_impl() defined in _2.so and
535   // above the correct _impl() is one in the executable.
536   //
537   // libtest_check_order_reloc_root.so
538   // |
539   // +-> ..._1.so <- empty
540   // |
541   // +-> ..._2.so <- gives incorrect answer for answer_main_impl()
542   //
543 
544   void* handle = dlopen("libtest_check_order_reloc_root.so", RTLD_NOW | RTLD_NOLOAD);
545   ASSERT_TRUE(handle == nullptr);
546 #ifdef __BIONIC__
547   // TODO: glibc returns nullptr on dlerror() here. Is it bug?
548   ASSERT_STREQ("dlopen failed: library \"libtest_check_order_reloc_root.so\" wasn't loaded and RTLD_NOLOAD prevented it", dlerror());
549 #endif
550 
551   handle = dlopen("libtest_check_order_reloc_root.so", RTLD_NOW | RTLD_LOCAL);
552   ASSERT_TRUE(handle != nullptr) << dlerror();
553 
554   typedef int (*fn_t) (void);
555   fn_t fn = reinterpret_cast<fn_t>(dlsym(handle, "check_order_reloc_root_get_answer"));
556   ASSERT_TRUE(fn != nullptr) << dlerror();
557   ASSERT_EQ(42, fn());
558 
559   ASSERT_EQ(0, dlclose(handle));
560 }
561 
TEST(dlfcn,dlopen_check_rtld_local)562 TEST(dlfcn, dlopen_check_rtld_local) {
563   void* sym = dlsym(RTLD_DEFAULT, "dlopen_testlib_simple_func");
564   ASSERT_TRUE(sym == nullptr);
565 
566   // implicit RTLD_LOCAL
567   void* handle = dlopen("libtest_simple.so", RTLD_NOW);
568   sym = dlsym(RTLD_DEFAULT, "dlopen_testlib_simple_func");
569   ASSERT_TRUE(sym == nullptr);
570   ASSERT_SUBSTR("undefined symbol: dlopen_testlib_simple_func", dlerror());
571   sym = dlsym(handle, "dlopen_testlib_simple_func");
572   ASSERT_TRUE(sym != nullptr);
573   ASSERT_TRUE(reinterpret_cast<bool (*)(void)>(sym)());
574   dlclose(handle);
575 
576   // explicit RTLD_LOCAL
577   handle = dlopen("libtest_simple.so", RTLD_NOW | RTLD_LOCAL);
578   sym = dlsym(RTLD_DEFAULT, "dlopen_testlib_simple_func");
579   ASSERT_TRUE(sym == nullptr);
580   ASSERT_SUBSTR("undefined symbol: dlopen_testlib_simple_func", dlerror());
581   sym = dlsym(handle, "dlopen_testlib_simple_func");
582   ASSERT_TRUE(sym != nullptr);
583   ASSERT_TRUE(reinterpret_cast<bool (*)(void)>(sym)());
584   dlclose(handle);
585 }
586 
TEST(dlfcn,dlopen_check_rtld_global)587 TEST(dlfcn, dlopen_check_rtld_global) {
588   void* sym = dlsym(RTLD_DEFAULT, "dlopen_testlib_simple_func");
589   ASSERT_TRUE(sym == nullptr);
590 
591   void* handle = dlopen("libtest_simple.so", RTLD_NOW | RTLD_GLOBAL);
592   ASSERT_TRUE(handle != nullptr) << dlerror();
593   sym = dlsym(RTLD_DEFAULT, "dlopen_testlib_simple_func");
594   ASSERT_TRUE(sym != nullptr) << dlerror();
595   ASSERT_TRUE(reinterpret_cast<bool (*)(void)>(sym)());
596   dlclose(handle);
597 
598   // RTLD_GLOBAL implies RTLD_NODELETE, let's check that
599   void* sym_after_dlclose = dlsym(RTLD_DEFAULT, "dlopen_testlib_simple_func");
600   ASSERT_EQ(sym, sym_after_dlclose);
601 
602   // Check if dlsym() for main program's handle searches RTLD_GLOBAL
603   // shared libraries after symbol was not found in the main executable
604   // and dependent libraries.
605   void* handle_for_main_executable = dlopen(nullptr, RTLD_NOW);
606   sym = dlsym(handle_for_main_executable, "dlopen_testlib_simple_func");
607   ASSERT_TRUE(sym != nullptr) << dlerror();
608 
609   dlclose(handle_for_main_executable);
610 }
611 
612 // libtest_with_dependency_loop.so -> libtest_with_dependency_loop_a.so ->
613 // libtest_with_dependency_loop_b.so -> libtest_with_dependency_loop_c.so ->
614 // libtest_with_dependency_loop_a.so
TEST(dlfcn,dlopen_check_loop)615 TEST(dlfcn, dlopen_check_loop) {
616   void* handle = dlopen("libtest_with_dependency_loop.so", RTLD_NOW);
617   ASSERT_TRUE(handle != nullptr) << dlerror();
618   void* f = dlsym(handle, "dlopen_test_loopy_function");
619   ASSERT_TRUE(f != nullptr) << dlerror();
620   EXPECT_TRUE(reinterpret_cast<bool (*)(void)>(f)());
621   ASSERT_EQ(0, dlclose(handle));
622 
623   // dlopen second time to make sure that the library was unloaded correctly
624   handle = dlopen("libtest_with_dependency_loop.so", RTLD_NOW | RTLD_NOLOAD);
625   ASSERT_TRUE(handle == nullptr);
626 #ifdef __BIONIC__
627   ASSERT_STREQ("dlopen failed: library \"libtest_with_dependency_loop.so\" wasn't loaded and RTLD_NOLOAD prevented it", dlerror());
628 #else
629   // TODO: glibc returns nullptr on dlerror() here. Is it bug?
630   ASSERT_TRUE(dlerror() == nullptr);
631 #endif
632 
633   handle = dlopen("libtest_with_dependency_a.so", RTLD_NOW | RTLD_NOLOAD);
634   ASSERT_TRUE(handle == nullptr);
635 }
636 
TEST(dlfcn,dlopen_nodelete)637 TEST(dlfcn, dlopen_nodelete) {
638   static bool is_unloaded = false;
639 
640   void* handle = dlopen("libtest_nodelete_1.so", RTLD_NOW | RTLD_NODELETE);
641   ASSERT_TRUE(handle != nullptr) << dlerror();
642   void (*set_unload_flag_ptr)(bool*);
643   set_unload_flag_ptr = reinterpret_cast<void (*)(bool*)>(dlsym(handle, "dlopen_nodelete_1_set_unload_flag_ptr"));
644   ASSERT_TRUE(set_unload_flag_ptr != nullptr) << dlerror();
645   set_unload_flag_ptr(&is_unloaded);
646 
647   uint32_t* taxicab_number = reinterpret_cast<uint32_t*>(dlsym(handle, "dlopen_nodelete_1_taxicab_number"));
648   ASSERT_TRUE(taxicab_number != nullptr) << dlerror();
649   ASSERT_EQ(1729U, *taxicab_number);
650   *taxicab_number = 2;
651 
652   dlclose(handle);
653   ASSERT_TRUE(!is_unloaded);
654 
655   uint32_t* taxicab_number_after_dlclose = reinterpret_cast<uint32_t*>(dlsym(handle, "dlopen_nodelete_1_taxicab_number"));
656   ASSERT_EQ(taxicab_number_after_dlclose, taxicab_number);
657   ASSERT_EQ(2U, *taxicab_number_after_dlclose);
658 
659 
660   handle = dlopen("libtest_nodelete_1.so", RTLD_NOW);
661   uint32_t* taxicab_number2 = reinterpret_cast<uint32_t*>(dlsym(handle, "dlopen_nodelete_1_taxicab_number"));
662   ASSERT_EQ(taxicab_number2, taxicab_number);
663 
664   ASSERT_EQ(2U, *taxicab_number2);
665 
666   dlclose(handle);
667   ASSERT_TRUE(!is_unloaded);
668 }
669 
TEST(dlfcn,dlopen_nodelete_on_second_dlopen)670 TEST(dlfcn, dlopen_nodelete_on_second_dlopen) {
671   static bool is_unloaded = false;
672 
673   void* handle = dlopen("libtest_nodelete_2.so", RTLD_NOW);
674   ASSERT_TRUE(handle != nullptr) << dlerror();
675   void (*set_unload_flag_ptr)(bool*);
676   set_unload_flag_ptr = reinterpret_cast<void (*)(bool*)>(dlsym(handle, "dlopen_nodelete_2_set_unload_flag_ptr"));
677   ASSERT_TRUE(set_unload_flag_ptr != nullptr) << dlerror();
678   set_unload_flag_ptr(&is_unloaded);
679 
680   uint32_t* taxicab_number = reinterpret_cast<uint32_t*>(dlsym(handle, "dlopen_nodelete_2_taxicab_number"));
681   ASSERT_TRUE(taxicab_number != nullptr) << dlerror();
682 
683   ASSERT_EQ(1729U, *taxicab_number);
684   *taxicab_number = 2;
685 
686   // This RTLD_NODELETE should be ignored
687   void* handle1 = dlopen("libtest_nodelete_2.so", RTLD_NOW | RTLD_NODELETE);
688   ASSERT_TRUE(handle1 != nullptr) << dlerror();
689   ASSERT_EQ(handle, handle1);
690 
691   dlclose(handle1);
692   dlclose(handle);
693 
694   ASSERT_TRUE(is_unloaded);
695 }
696 
TEST(dlfcn,dlopen_nodelete_dt_flags_1)697 TEST(dlfcn, dlopen_nodelete_dt_flags_1) {
698   static bool is_unloaded = false;
699 
700   void* handle = dlopen("libtest_nodelete_dt_flags_1.so", RTLD_NOW);
701   ASSERT_TRUE(handle != nullptr) << dlerror();
702   void (*set_unload_flag_ptr)(bool*);
703   set_unload_flag_ptr = reinterpret_cast<void (*)(bool*)>(dlsym(handle, "dlopen_nodelete_dt_flags_1_set_unload_flag_ptr"));
704   ASSERT_TRUE(set_unload_flag_ptr != nullptr) << dlerror();
705   set_unload_flag_ptr(&is_unloaded);
706 
707   dlclose(handle);
708   ASSERT_TRUE(!is_unloaded);
709 }
710 
TEST(dlfcn,dlsym_df_1_global)711 TEST(dlfcn, dlsym_df_1_global) {
712   void* handle = dlopen("libtest_dlsym_df_1_global.so", RTLD_NOW);
713   ASSERT_TRUE(handle != nullptr) << dlerror();
714   int (*get_answer)();
715   get_answer = reinterpret_cast<int (*)()>(dlsym(handle, "dl_df_1_global_get_answer"));
716   ASSERT_TRUE(get_answer != nullptr) << dlerror();
717   ASSERT_EQ(42, get_answer());
718   ASSERT_EQ(0, dlclose(handle));
719 }
720 
TEST(dlfcn,dlopen_failure)721 TEST(dlfcn, dlopen_failure) {
722   void* self = dlopen("/does/not/exist", RTLD_NOW);
723   ASSERT_TRUE(self == nullptr);
724 #if defined(__BIONIC__)
725   ASSERT_STREQ("dlopen failed: library \"/does/not/exist\" not found", dlerror());
726 #else
727   ASSERT_STREQ("/does/not/exist: cannot open shared object file: No such file or directory", dlerror());
728 #endif
729 }
730 
ConcurrentDlErrorFn(void *)731 static void* ConcurrentDlErrorFn(void*) {
732   dlopen("/child/thread", RTLD_NOW);
733   return reinterpret_cast<void*>(strdup(dlerror()));
734 }
735 
TEST(dlfcn,dlerror_concurrent)736 TEST(dlfcn, dlerror_concurrent) {
737   dlopen("/main/thread", RTLD_NOW);
738   const char* main_thread_error = dlerror();
739   ASSERT_SUBSTR("/main/thread", main_thread_error);
740 
741   pthread_t t;
742   ASSERT_EQ(0, pthread_create(&t, nullptr, ConcurrentDlErrorFn, nullptr));
743   void* result;
744   ASSERT_EQ(0, pthread_join(t, &result));
745   char* child_thread_error = static_cast<char*>(result);
746   ASSERT_SUBSTR("/child/thread", child_thread_error);
747   free(child_thread_error);
748 
749   ASSERT_SUBSTR("/main/thread", main_thread_error);
750 }
751 
TEST(dlfcn,dlsym_failures)752 TEST(dlfcn, dlsym_failures) {
753   dlerror(); // Clear any pending errors.
754   void* self = dlopen(nullptr, RTLD_NOW);
755   ASSERT_TRUE(self != nullptr);
756   ASSERT_TRUE(dlerror() == nullptr);
757 
758   void* sym;
759 
760 #if defined(__BIONIC__) && !defined(__LP64__)
761   // RTLD_DEFAULT in lp32 bionic is not (void*)0
762   // so it can be distinguished from the NULL handle.
763   sym = dlsym(nullptr, "test");
764   ASSERT_TRUE(sym == nullptr);
765   ASSERT_STREQ("dlsym failed: library handle is null", dlerror());
766 #endif
767 
768   // Symbol that doesn't exist.
769   sym = dlsym(self, "ThisSymbolDoesNotExist");
770   ASSERT_TRUE(sym == nullptr);
771   ASSERT_SUBSTR("undefined symbol: ThisSymbolDoesNotExist", dlerror());
772 
773   ASSERT_EQ(0, dlclose(self));
774 }
775 
TEST(dlfcn,dladdr_executable)776 TEST(dlfcn, dladdr_executable) {
777   dlerror(); // Clear any pending errors.
778   void* self = dlopen(nullptr, RTLD_NOW);
779   ASSERT_TRUE(self != nullptr);
780   ASSERT_TRUE(dlerror() == nullptr);
781 
782   void* sym = dlsym(self, "DlSymTestFunction");
783   ASSERT_TRUE(sym != nullptr);
784 
785   // Deliberately ask dladdr for an address inside a symbol, rather than the symbol base address.
786   void* addr = reinterpret_cast<void*>(reinterpret_cast<uintptr_t>(sym) + 2);
787 
788   Dl_info info;
789   int rc = dladdr(addr, &info);
790   ASSERT_NE(rc, 0); // Zero on error, non-zero on success.
791 
792   // Get the name of this executable.
793   const std::string& executable_path = get_executable_path();
794 
795   // The filename should be that of this executable.
796   char dli_realpath[PATH_MAX];
797   ASSERT_TRUE(realpath(info.dli_fname, dli_realpath) != nullptr);
798   ASSERT_STREQ(executable_path.c_str(), dli_realpath);
799 
800   // The symbol name should be the symbol we looked up.
801   ASSERT_STREQ(info.dli_sname, "DlSymTestFunction");
802 
803   // The address should be the exact address of the symbol.
804   ASSERT_EQ(info.dli_saddr, sym);
805 
806   std::vector<map_record> maps;
807   ASSERT_TRUE(Maps::parse_maps(&maps));
808 
809   void* base_address = nullptr;
810   for (const map_record& rec : maps) {
811     if (executable_path == rec.pathname) {
812       base_address = reinterpret_cast<void*>(rec.addr_start);
813       break;
814     }
815   }
816 
817   // The base address should be the address we were loaded at.
818   ASSERT_EQ(info.dli_fbase, base_address);
819 
820   ASSERT_EQ(0, dlclose(self));
821 }
822 
TEST(dlfcn,dlopen_executable_by_absolute_path)823 TEST(dlfcn, dlopen_executable_by_absolute_path) {
824   void* handle1 = dlopen(nullptr, RTLD_NOW);
825   ASSERT_TRUE(handle1 != nullptr) << dlerror();
826 
827   void* handle2 = dlopen(get_executable_path().c_str(), RTLD_NOW);
828   ASSERT_TRUE(handle2 != nullptr) << dlerror();
829 
830 #if defined(__BIONIC__)
831   ASSERT_EQ(handle1, handle2);
832 #else
833   GTEST_LOG_(INFO) << "Skipping ASSERT_EQ(handle1, handle2) for glibc: "
834                       "it loads a separate copy of the main executable "
835                       "on dlopen by absolute path.";
836 #endif
837 }
838 
839 #if defined(__LP64__)
840 #define PATH_TO_SYSTEM_LIB "/system/lib64/"
841 #else
842 #define PATH_TO_SYSTEM_LIB "/system/lib/"
843 #endif
844 #define PATH_TO_LIBC PATH_TO_SYSTEM_LIB "libc.so"
845 
TEST(dlfcn,dladdr_libc)846 TEST(dlfcn, dladdr_libc) {
847 #if defined(__BIONIC__)
848   Dl_info info;
849   void* addr = reinterpret_cast<void*>(puts); // well-known libc function
850   ASSERT_TRUE(dladdr(addr, &info) != 0);
851 
852   // /system/lib is symlink when this test is executed on host.
853   char libc_realpath[PATH_MAX];
854   ASSERT_TRUE(realpath(PATH_TO_LIBC, libc_realpath) == libc_realpath);
855 
856   ASSERT_STREQ(libc_realpath, info.dli_fname);
857   // TODO: add check for dfi_fbase
858   ASSERT_STREQ("puts", info.dli_sname);
859   ASSERT_EQ(addr, info.dli_saddr);
860 #else
861   GTEST_LOG_(INFO) << "This test does nothing for glibc. Glibc returns path from ldconfig "
862       "for libc.so, which is symlink itself (not a realpath).\n";
863 #endif
864 }
865 
TEST(dlfcn,dladdr_invalid)866 TEST(dlfcn, dladdr_invalid) {
867   Dl_info info;
868 
869   dlerror(); // Clear any pending errors.
870 
871   // No symbol corresponding to NULL.
872   ASSERT_EQ(dladdr(nullptr, &info), 0); // Zero on error, non-zero on success.
873   ASSERT_TRUE(dlerror() == nullptr); // dladdr(3) doesn't set dlerror(3).
874 
875   // No symbol corresponding to a stack address.
876   ASSERT_EQ(dladdr(&info, &info), 0); // Zero on error, non-zero on success.
877   ASSERT_TRUE(dlerror() == nullptr); // dladdr(3) doesn't set dlerror(3).
878 }
879 
880 // GNU-style ELF hash tables are incompatible with the MIPS ABI.
881 // MIPS requires .dynsym to be sorted to match the GOT but GNU-style requires sorting by hash code.
TEST(dlfcn,dlopen_library_with_only_gnu_hash)882 TEST(dlfcn, dlopen_library_with_only_gnu_hash) {
883 #if !defined(__mips__)
884   dlerror(); // Clear any pending errors.
885   void* handle = dlopen("libgnu-hash-table-library.so", RTLD_NOW);
886   ASSERT_TRUE(handle != nullptr) << dlerror();
887   auto guard = make_scope_guard([&]() {
888     dlclose(handle);
889   });
890   void* sym = dlsym(handle, "getRandomNumber");
891   ASSERT_TRUE(sym != nullptr) << dlerror();
892   int (*fn)(void);
893   fn = reinterpret_cast<int (*)(void)>(sym);
894   EXPECT_EQ(4, fn());
895 
896   Dl_info dlinfo;
897   ASSERT_TRUE(0 != dladdr(reinterpret_cast<void*>(fn), &dlinfo));
898 
899   ASSERT_TRUE(fn == dlinfo.dli_saddr);
900   ASSERT_STREQ("getRandomNumber", dlinfo.dli_sname);
901   ASSERT_SUBSTR("libgnu-hash-table-library.so", dlinfo.dli_fname);
902 #else
903   GTEST_LOG_(INFO) << "This test does nothing for mips/mips64; mips toolchain does not support '--hash-style=gnu'\n";
904 #endif
905 }
906 
TEST(dlfcn,dlopen_library_with_only_sysv_hash)907 TEST(dlfcn, dlopen_library_with_only_sysv_hash) {
908   void* handle = dlopen("libsysv-hash-table-library.so", RTLD_NOW);
909   ASSERT_TRUE(handle != nullptr) << dlerror();
910   auto guard = make_scope_guard([&]() {
911     dlclose(handle);
912   });
913   void* sym = dlsym(handle, "getRandomNumber");
914   ASSERT_TRUE(sym != nullptr) << dlerror();
915   int (*fn)(void);
916   fn = reinterpret_cast<int (*)(void)>(sym);
917   EXPECT_EQ(4, fn());
918 
919   Dl_info dlinfo;
920   ASSERT_TRUE(0 != dladdr(reinterpret_cast<void*>(fn), &dlinfo));
921 
922   ASSERT_TRUE(fn == dlinfo.dli_saddr);
923   ASSERT_STREQ("getRandomNumber", dlinfo.dli_sname);
924   ASSERT_SUBSTR("libsysv-hash-table-library.so", dlinfo.dli_fname);
925 }
926 
TEST(dlfcn,dlopen_bad_flags)927 TEST(dlfcn, dlopen_bad_flags) {
928   dlerror(); // Clear any pending errors.
929   void* handle;
930 
931 #if defined(__GLIBC__)
932   // glibc was smart enough not to define RTLD_NOW as 0, so it can detect missing flags.
933   handle = dlopen(nullptr, 0);
934   ASSERT_TRUE(handle == nullptr);
935   ASSERT_SUBSTR("invalid", dlerror());
936 #endif
937 
938   handle = dlopen(nullptr, 0xffffffff);
939   ASSERT_TRUE(handle == nullptr);
940   ASSERT_SUBSTR("invalid", dlerror());
941 
942   // glibc actually allows you to choose both RTLD_NOW and RTLD_LAZY at the same time, and so do we.
943   handle = dlopen(nullptr, RTLD_NOW|RTLD_LAZY);
944   ASSERT_TRUE(handle != nullptr);
945   ASSERT_SUBSTR(nullptr, dlerror());
946 }
947 
TEST(dlfcn,rtld_default_unknown_symbol)948 TEST(dlfcn, rtld_default_unknown_symbol) {
949   void* addr = dlsym(RTLD_DEFAULT, "ANY_UNKNOWN_SYMBOL_NAME");
950   ASSERT_TRUE(addr == nullptr);
951 }
952 
TEST(dlfcn,rtld_default_known_symbol)953 TEST(dlfcn, rtld_default_known_symbol) {
954   void* addr = dlsym(RTLD_DEFAULT, "fopen");
955   ASSERT_TRUE(addr != nullptr);
956 }
957 
TEST(dlfcn,rtld_next_unknown_symbol)958 TEST(dlfcn, rtld_next_unknown_symbol) {
959   void* addr = dlsym(RTLD_NEXT, "ANY_UNKNOWN_SYMBOL_NAME");
960   ASSERT_TRUE(addr == nullptr);
961 }
962 
TEST(dlfcn,rtld_next_known_symbol)963 TEST(dlfcn, rtld_next_known_symbol) {
964   void* addr = dlsym(RTLD_NEXT, "fopen");
965   ASSERT_TRUE(addr != nullptr);
966 }
967 
TEST(dlfcn,dlsym_weak_func)968 TEST(dlfcn, dlsym_weak_func) {
969   dlerror();
970   void* handle = dlopen("libtest_dlsym_weak_func.so", RTLD_NOW);
971   ASSERT_TRUE(handle != nullptr);
972 
973   int (*weak_func)();
974   weak_func = reinterpret_cast<int (*)()>(dlsym(handle, "weak_func"));
975   ASSERT_TRUE(weak_func != nullptr) << "dlerror: " << dlerror();
976   EXPECT_EQ(42, weak_func());
977   dlclose(handle);
978 }
979 
TEST(dlfcn,dlopen_undefined_weak_func)980 TEST(dlfcn, dlopen_undefined_weak_func) {
981   void* handle = dlopen("libtest_dlopen_weak_undefined_func.so", RTLD_NOW);
982   ASSERT_TRUE(handle != nullptr) << dlerror();
983   int (*weak_func)();
984   weak_func = reinterpret_cast<int (*)()>(dlsym(handle, "use_weak_undefined_func"));
985   ASSERT_TRUE(weak_func != nullptr) << dlerror();
986   EXPECT_EQ(6551, weak_func());
987   dlclose(handle);
988 }
989 
TEST(dlfcn,dlopen_symlink)990 TEST(dlfcn, dlopen_symlink) {
991   void* handle1 = dlopen("libdlext_test.so", RTLD_NOW);
992   void* handle2 = dlopen("libdlext_test_v2.so", RTLD_NOW);
993   ASSERT_TRUE(handle1 != nullptr);
994   ASSERT_TRUE(handle2 != nullptr);
995   ASSERT_EQ(handle1, handle2);
996   dlclose(handle1);
997   dlclose(handle2);
998 }
999 
1000 // libtest_dlopen_from_ctor_main.so depends on
1001 // libtest_dlopen_from_ctor.so which has a constructor
1002 // that calls dlopen(libc...). This is to test the situation
1003 // described in b/7941716.
TEST(dlfcn,dlopen_dlopen_from_ctor)1004 TEST(dlfcn, dlopen_dlopen_from_ctor) {
1005 #if defined(__BIONIC__)
1006   void* handle = dlopen("libtest_dlopen_from_ctor_main.so", RTLD_NOW);
1007   ASSERT_TRUE(handle != nullptr) << dlerror();
1008   dlclose(handle);
1009 #else
1010   GTEST_LOG_(INFO) << "This test is disabled for glibc (glibc segfaults if you try to call dlopen from a constructor).\n";
1011 #endif
1012 }
1013 
TEST(dlfcn,symbol_versioning_use_v1)1014 TEST(dlfcn, symbol_versioning_use_v1) {
1015   void* handle = dlopen("libtest_versioned_uselibv1.so", RTLD_NOW);
1016   ASSERT_TRUE(handle != nullptr) << dlerror();
1017   typedef int (*fn_t)();
1018   fn_t fn = reinterpret_cast<fn_t>(dlsym(handle, "get_function_version"));
1019   ASSERT_TRUE(fn != nullptr) << dlerror();
1020   ASSERT_EQ(1, fn());
1021   dlclose(handle);
1022 }
1023 
TEST(dlfcn,symbol_versioning_use_v2)1024 TEST(dlfcn, symbol_versioning_use_v2) {
1025   void* handle = dlopen("libtest_versioned_uselibv2.so", RTLD_NOW);
1026   ASSERT_TRUE(handle != nullptr) << dlerror();
1027   typedef int (*fn_t)();
1028   fn_t fn = reinterpret_cast<fn_t>(dlsym(handle, "get_function_version"));
1029   ASSERT_TRUE(fn != nullptr) << dlerror();
1030   ASSERT_EQ(2, fn());
1031   dlclose(handle);
1032 }
1033 
TEST(dlfcn,symbol_versioning_use_other_v2)1034 TEST(dlfcn, symbol_versioning_use_other_v2) {
1035   void* handle = dlopen("libtest_versioned_uselibv2_other.so", RTLD_NOW);
1036   ASSERT_TRUE(handle != nullptr) << dlerror();
1037   typedef int (*fn_t)();
1038   fn_t fn = reinterpret_cast<fn_t>(dlsym(handle, "get_function_version"));
1039   ASSERT_TRUE(fn != nullptr) << dlerror();
1040   ASSERT_EQ(20, fn());
1041   dlclose(handle);
1042 }
1043 
TEST(dlfcn,symbol_versioning_use_other_v3)1044 TEST(dlfcn, symbol_versioning_use_other_v3) {
1045   void* handle = dlopen("libtest_versioned_uselibv3_other.so", RTLD_NOW);
1046   ASSERT_TRUE(handle != nullptr) << dlerror();
1047   typedef int (*fn_t)();
1048   fn_t fn = reinterpret_cast<fn_t>(dlsym(handle, "get_function_version"));
1049   ASSERT_TRUE(fn != nullptr) << dlerror();
1050   ASSERT_EQ(3, fn());
1051   dlclose(handle);
1052 }
1053 
TEST(dlfcn,symbol_versioning_default_via_dlsym)1054 TEST(dlfcn, symbol_versioning_default_via_dlsym) {
1055   void* handle = dlopen("libtest_versioned_lib.so", RTLD_NOW);
1056   ASSERT_TRUE(handle != nullptr) << dlerror();
1057   typedef int (*fn_t)();
1058   fn_t fn = reinterpret_cast<fn_t>(dlsym(handle, "versioned_function"));
1059   ASSERT_TRUE(fn != nullptr) << dlerror();
1060   ASSERT_EQ(3, fn()); // the default version is 3
1061   dlclose(handle);
1062 }
1063 
TEST(dlfcn,dlvsym_smoke)1064 TEST(dlfcn, dlvsym_smoke) {
1065   void* handle = dlopen("libtest_versioned_lib.so", RTLD_NOW);
1066   ASSERT_TRUE(handle != nullptr) << dlerror();
1067   typedef int (*fn_t)();
1068 
1069   {
1070     fn_t fn = reinterpret_cast<fn_t>(dlvsym(handle, "versioned_function", "nonversion"));
1071     ASSERT_TRUE(fn == nullptr);
1072     ASSERT_SUBSTR("undefined symbol: versioned_function, version nonversion", dlerror());
1073   }
1074 
1075   {
1076     fn_t fn = reinterpret_cast<fn_t>(dlvsym(handle, "versioned_function", "TESTLIB_V2"));
1077     ASSERT_TRUE(fn != nullptr) << dlerror();
1078     ASSERT_EQ(2, fn());
1079   }
1080 
1081   dlclose(handle);
1082 }
1083 
1084 // This preempts the implementation from libtest_versioned_lib.so
version_zero_function()1085 extern "C" int version_zero_function() {
1086   return 0;
1087 }
1088 
1089 // This preempts the implementation from libtest_versioned_uselibv*.so
version_zero_function2()1090 extern "C" int version_zero_function2() {
1091   return 0;
1092 }
1093 
TEST(dlfcn,dt_runpath_smoke)1094 TEST(dlfcn, dt_runpath_smoke) {
1095   void* handle = dlopen("libtest_dt_runpath_d.so", RTLD_NOW);
1096   ASSERT_TRUE(handle != nullptr) << dlerror();
1097 
1098   typedef void *(* dlopen_b_fn)();
1099   dlopen_b_fn fn = (dlopen_b_fn)dlsym(handle, "dlopen_b");
1100   ASSERT_TRUE(fn != nullptr) << dlerror();
1101 
1102   void *p = fn();
1103   ASSERT_TRUE(p != nullptr);
1104 
1105   dlclose(handle);
1106 }
1107 
TEST(dlfcn,dt_runpath_absolute_path)1108 TEST(dlfcn, dt_runpath_absolute_path) {
1109   void* handle = dlopen(PATH_TO_SYSTEM_LIB "libtest_dt_runpath_d.so", RTLD_NOW);
1110   ASSERT_TRUE(handle != nullptr) << dlerror();
1111 
1112   typedef void *(* dlopen_b_fn)();
1113   dlopen_b_fn fn = (dlopen_b_fn)dlsym(handle, "dlopen_b");
1114   ASSERT_TRUE(fn != nullptr) << dlerror();
1115 
1116   void *p = fn();
1117   ASSERT_TRUE(p != nullptr);
1118 
1119   dlclose(handle);
1120 }
1121