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      1 /*
      2  * Copyright (C) 2014 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 <elf.h>
     21 #include <errno.h>
     22 #include <fcntl.h>
     23 #include <inttypes.h>
     24 #include <stdio.h>
     25 #include <string.h>
     26 #include <unistd.h>
     27 
     28 #include <android/dlext.h>
     29 #include <android-base/strings.h>
     30 
     31 #include <linux/memfd.h>
     32 #include <sys/mman.h>
     33 #include <sys/types.h>
     34 #include <sys/vfs.h>
     35 #include <sys/wait.h>
     36 
     37 #include <pagemap/pagemap.h>
     38 #include <ziparchive/zip_archive.h>
     39 
     40 #include "gtest_globals.h"
     41 #include "TemporaryFile.h"
     42 #include "utils.h"
     43 #include "dlext_private.h"
     44 #include "dlfcn_symlink_support.h"
     45 
     46 #define ASSERT_DL_NOTNULL(ptr) \
     47     ASSERT_TRUE((ptr) != nullptr) << "dlerror: " << dlerror()
     48 
     49 #define ASSERT_DL_ZERO(i) \
     50     ASSERT_EQ(0, i) << "dlerror: " << dlerror()
     51 
     52 #define ASSERT_NOERROR(i) \
     53     ASSERT_NE(-1, i) << "errno: " << strerror(errno)
     54 
     55 #define ASSERT_SUBSTR(needle, haystack) \
     56     ASSERT_PRED_FORMAT2(::testing::IsSubstring, needle, haystack)
     57 
     58 
     59 typedef int (*fn)(void);
     60 constexpr const char* kLibName = "libdlext_test.so";
     61 constexpr const char* kLibNameNoRelro = "libdlext_test_norelro.so";
     62 constexpr const char* kLibZipSimpleZip = "libdir/libatest_simple_zip.so";
     63 constexpr auto kLibSize = 1024 * 1024; // how much address space to reserve for it
     64 
     65 class DlExtTest : public ::testing::Test {
     66 protected:
     67   virtual void SetUp() {
     68     handle_ = nullptr;
     69     // verify that we don't have the library loaded already
     70     void* h = dlopen(kLibName, RTLD_NOW | RTLD_NOLOAD);
     71     ASSERT_TRUE(h == nullptr);
     72     h = dlopen(kLibNameNoRelro, RTLD_NOW | RTLD_NOLOAD);
     73     ASSERT_TRUE(h == nullptr);
     74     // call dlerror() to swallow the error, and check it was the one we wanted
     75     ASSERT_EQ(std::string("dlopen failed: library \"") + kLibNameNoRelro + "\" wasn't loaded and RTLD_NOLOAD prevented it", dlerror());
     76   }
     77 
     78   virtual void TearDown() {
     79     if (handle_ != nullptr) {
     80       ASSERT_DL_ZERO(dlclose(handle_));
     81     }
     82   }
     83 
     84   void* handle_;
     85 };
     86 
     87 TEST_F(DlExtTest, ExtInfoNull) {
     88   handle_ = android_dlopen_ext(kLibName, RTLD_NOW, nullptr);
     89   ASSERT_DL_NOTNULL(handle_);
     90   fn f = reinterpret_cast<fn>(dlsym(handle_, "getRandomNumber"));
     91   ASSERT_DL_NOTNULL(f);
     92   EXPECT_EQ(4, f());
     93 }
     94 
     95 TEST_F(DlExtTest, ExtInfoNoFlags) {
     96   android_dlextinfo extinfo;
     97   extinfo.flags = 0;
     98   handle_ = android_dlopen_ext(kLibName, RTLD_NOW, &extinfo);
     99   ASSERT_DL_NOTNULL(handle_);
    100   fn f = reinterpret_cast<fn>(dlsym(handle_, "getRandomNumber"));
    101   ASSERT_DL_NOTNULL(f);
    102   EXPECT_EQ(4, f());
    103 }
    104 
    105 TEST_F(DlExtTest, ExtInfoUseFd) {
    106   const std::string lib_path = get_testlib_root() + "/libdlext_test_fd/libdlext_test_fd.so";
    107 
    108   android_dlextinfo extinfo;
    109   extinfo.flags = ANDROID_DLEXT_USE_LIBRARY_FD;
    110   extinfo.library_fd = TEMP_FAILURE_RETRY(open(lib_path.c_str(), O_RDONLY | O_CLOEXEC));
    111   ASSERT_TRUE(extinfo.library_fd != -1);
    112   handle_ = android_dlopen_ext(lib_path.c_str(), RTLD_NOW, &extinfo);
    113   ASSERT_DL_NOTNULL(handle_);
    114   fn f = reinterpret_cast<fn>(dlsym(handle_, "getRandomNumber"));
    115   ASSERT_DL_NOTNULL(f);
    116   EXPECT_EQ(4, f());
    117 
    118   uint32_t* taxicab_number = reinterpret_cast<uint32_t*>(dlsym(handle_, "dlopen_testlib_taxicab_number"));
    119   ASSERT_DL_NOTNULL(taxicab_number);
    120   EXPECT_EQ(1729U, *taxicab_number);
    121 }
    122 
    123 TEST_F(DlExtTest, ExtInfoUseFdWithOffset) {
    124   const std::string lib_path = get_testlib_root() + "/libdlext_test_zip/libdlext_test_zip_zipaligned.zip";
    125 
    126   android_dlextinfo extinfo;
    127   extinfo.flags = ANDROID_DLEXT_USE_LIBRARY_FD | ANDROID_DLEXT_USE_LIBRARY_FD_OFFSET;
    128   extinfo.library_fd = TEMP_FAILURE_RETRY(open(lib_path.c_str(), O_RDONLY | O_CLOEXEC));
    129 
    130   // Find the offset of the shared library in the zip.
    131   ZipArchiveHandle handle;
    132   ASSERT_EQ(0, OpenArchive(lib_path.c_str(), &handle));
    133   ZipEntry zip_entry;
    134   ZipString zip_name;
    135   zip_name.name = reinterpret_cast<const uint8_t*>(kLibZipSimpleZip);
    136   zip_name.name_length = strlen(kLibZipSimpleZip);
    137   ASSERT_EQ(0, FindEntry(handle, zip_name, &zip_entry));
    138   extinfo.library_fd_offset = zip_entry.offset;
    139   CloseArchive(handle);
    140 
    141   handle_ = android_dlopen_ext(lib_path.c_str(), RTLD_NOW, &extinfo);
    142   ASSERT_DL_NOTNULL(handle_);
    143 
    144   uint32_t* taxicab_number = reinterpret_cast<uint32_t*>(dlsym(handle_, "dlopen_testlib_taxicab_number"));
    145   ASSERT_DL_NOTNULL(taxicab_number);
    146   EXPECT_EQ(1729U, *taxicab_number);
    147 }
    148 
    149 TEST_F(DlExtTest, ExtInfoUseFdWithInvalidOffset) {
    150   const std::string lib_path = get_testlib_root() + "/libdlext_test_zip/libdlext_test_zip_zipaligned.zip";
    151 
    152   android_dlextinfo extinfo;
    153   extinfo.flags = ANDROID_DLEXT_USE_LIBRARY_FD | ANDROID_DLEXT_USE_LIBRARY_FD_OFFSET;
    154   extinfo.library_fd = TEMP_FAILURE_RETRY(open(lib_path.c_str(), O_RDONLY | O_CLOEXEC));
    155   extinfo.library_fd_offset = 17;
    156 
    157   handle_ = android_dlopen_ext("libname_placeholder", RTLD_NOW, &extinfo);
    158   ASSERT_TRUE(handle_ == nullptr);
    159   ASSERT_STREQ("dlopen failed: file offset for the library \"libname_placeholder\" is not page-aligned: 17", dlerror());
    160 
    161   // Test an address above 2^44, for http://b/18178121 .
    162   extinfo.library_fd_offset = (5LL<<48) + PAGE_SIZE;
    163   handle_ = android_dlopen_ext("libname_placeholder", RTLD_NOW, &extinfo);
    164   ASSERT_TRUE(handle_ == nullptr);
    165   ASSERT_SUBSTR("dlopen failed: file offset for the library \"libname_placeholder\" >= file size", dlerror());
    166 
    167   extinfo.library_fd_offset = 0LL - PAGE_SIZE;
    168   handle_ = android_dlopen_ext("libname_placeholder", RTLD_NOW, &extinfo);
    169   ASSERT_TRUE(handle_ == nullptr);
    170   ASSERT_SUBSTR("dlopen failed: file offset for the library \"libname_placeholder\" is negative", dlerror());
    171 
    172   extinfo.library_fd_offset = 0;
    173   handle_ = android_dlopen_ext("libname_ignored", RTLD_NOW, &extinfo);
    174   ASSERT_TRUE(handle_ == nullptr);
    175   ASSERT_EQ("dlopen failed: \"" + lib_path + "\" has bad ELF magic", dlerror());
    176 
    177   // Check if dlsym works after unsuccessful dlopen().
    178   // Supply non-exiting one to make linker visit every soinfo.
    179   void* sym = dlsym(RTLD_DEFAULT, "this_symbol_does_not_exist___");
    180   ASSERT_TRUE(sym == nullptr);
    181 
    182   close(extinfo.library_fd);
    183 }
    184 
    185 TEST_F(DlExtTest, ExtInfoUseOffsetWithoutFd) {
    186   android_dlextinfo extinfo;
    187   extinfo.flags = ANDROID_DLEXT_USE_LIBRARY_FD_OFFSET;
    188   // This offset will not be used, so it doesn't matter.
    189   extinfo.library_fd_offset = 0;
    190 
    191   handle_ = android_dlopen_ext("/some/lib/that/does_not_exist", RTLD_NOW, &extinfo);
    192   ASSERT_TRUE(handle_ == nullptr);
    193   ASSERT_STREQ("dlopen failed: invalid extended flag combination (ANDROID_DLEXT_USE_LIBRARY_FD_OFFSET without ANDROID_DLEXT_USE_LIBRARY_FD): 0x20", dlerror());
    194 }
    195 
    196 TEST(dlext, android_dlopen_ext_force_load_smoke) {
    197   DlfcnSymlink symlink("android_dlopen_ext_force_load_smoke");
    198   const std::string symlink_name = basename(symlink.get_symlink_path().c_str());
    199   // 1. Open actual file
    200   void* handle = dlopen("libdlext_test.so", RTLD_NOW);
    201   ASSERT_DL_NOTNULL(handle);
    202   // 2. Open link with force_load flag set
    203   android_dlextinfo extinfo;
    204   extinfo.flags = ANDROID_DLEXT_FORCE_LOAD;
    205   void* handle2 = android_dlopen_ext(symlink_name.c_str(), RTLD_NOW, &extinfo);
    206   ASSERT_DL_NOTNULL(handle2);
    207   ASSERT_TRUE(handle != handle2);
    208 
    209   dlclose(handle2);
    210   dlclose(handle);
    211 }
    212 
    213 TEST(dlext, android_dlopen_ext_force_load_soname_exception) {
    214   DlfcnSymlink symlink("android_dlopen_ext_force_load_soname_exception");
    215   const std::string symlink_name = basename(symlink.get_symlink_path().c_str());
    216   // Check if soname lookup still returns already loaded library
    217   // when ANDROID_DLEXT_FORCE_LOAD flag is specified.
    218   void* handle = dlopen(symlink_name.c_str(), RTLD_NOW);
    219   ASSERT_DL_NOTNULL(handle);
    220 
    221   android_dlextinfo extinfo;
    222   extinfo.flags = ANDROID_DLEXT_FORCE_LOAD;
    223 
    224   // Note that 'libdlext_test.so' is dt_soname for the symlink_name
    225   void* handle2 = android_dlopen_ext("libdlext_test.so", RTLD_NOW, &extinfo);
    226 
    227   ASSERT_DL_NOTNULL(handle2);
    228   ASSERT_TRUE(handle == handle2);
    229 
    230   dlclose(handle2);
    231   dlclose(handle);
    232 }
    233 
    234 TEST(dlfcn, dlopen_from_zip_absolute_path) {
    235   const std::string lib_zip_path = "/libdlext_test_zip/libdlext_test_zip_zipaligned.zip";
    236   const std::string lib_path = get_testlib_root() + lib_zip_path;
    237 
    238   void* handle = dlopen((lib_path + "!/libdir/libatest_simple_zip.so").c_str(), RTLD_NOW);
    239   ASSERT_TRUE(handle != nullptr) << dlerror();
    240 
    241   uint32_t* taxicab_number = reinterpret_cast<uint32_t*>(dlsym(handle, "dlopen_testlib_taxicab_number"));
    242   ASSERT_DL_NOTNULL(taxicab_number);
    243   EXPECT_EQ(1729U, *taxicab_number);
    244 
    245   dlclose(handle);
    246 }
    247 
    248 TEST(dlfcn, dlopen_from_zip_with_dt_runpath) {
    249   const std::string lib_zip_path = "/libdlext_test_runpath_zip/libdlext_test_runpath_zip_zipaligned.zip";
    250   const std::string lib_path = get_testlib_root() + lib_zip_path;
    251 
    252   void* handle = dlopen((lib_path + "!/libdir/libtest_dt_runpath_d_zip.so").c_str(), RTLD_NOW);
    253 
    254   ASSERT_TRUE(handle != nullptr) << dlerror();
    255 
    256   typedef void *(* dlopen_b_fn)();
    257   dlopen_b_fn fn = (dlopen_b_fn)dlsym(handle, "dlopen_b");
    258   ASSERT_TRUE(fn != nullptr) << dlerror();
    259 
    260   void *p = fn();
    261   ASSERT_TRUE(p != nullptr) << dlerror();
    262 
    263   dlclose(p);
    264   dlclose(handle);
    265 }
    266 
    267 TEST(dlfcn, dlopen_from_zip_ld_library_path) {
    268   const std::string lib_zip_path = "/libdlext_test_zip/libdlext_test_zip_zipaligned.zip";
    269   const std::string lib_path = get_testlib_root() + lib_zip_path + "!/libdir";
    270 
    271   typedef void (*fn_t)(const char*);
    272   fn_t android_update_LD_LIBRARY_PATH =
    273       reinterpret_cast<fn_t>(dlsym(RTLD_DEFAULT, "android_update_LD_LIBRARY_PATH"));
    274 
    275   ASSERT_TRUE(android_update_LD_LIBRARY_PATH != nullptr) << dlerror();
    276 
    277   void* handle = dlopen("libdlext_test_zip.so", RTLD_NOW);
    278   ASSERT_TRUE(handle == nullptr);
    279 
    280   android_update_LD_LIBRARY_PATH(lib_path.c_str());
    281 
    282   handle = dlopen("libdlext_test_zip.so", RTLD_NOW);
    283   ASSERT_TRUE(handle != nullptr) << dlerror();
    284 
    285   int (*fn)(void);
    286   fn = reinterpret_cast<int (*)(void)>(dlsym(handle, "getRandomNumber"));
    287   ASSERT_TRUE(fn != nullptr);
    288   EXPECT_EQ(4, fn());
    289 
    290   uint32_t* taxicab_number =
    291           reinterpret_cast<uint32_t*>(dlsym(handle, "dlopen_testlib_taxicab_number"));
    292   ASSERT_DL_NOTNULL(taxicab_number);
    293   EXPECT_EQ(1729U, *taxicab_number);
    294 
    295   dlclose(handle);
    296 }
    297 
    298 
    299 TEST_F(DlExtTest, Reserved) {
    300   void* start = mmap(nullptr, kLibSize, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
    301   ASSERT_TRUE(start != MAP_FAILED);
    302   android_dlextinfo extinfo;
    303   extinfo.flags = ANDROID_DLEXT_RESERVED_ADDRESS;
    304   extinfo.reserved_addr = start;
    305   extinfo.reserved_size = kLibSize;
    306   handle_ = android_dlopen_ext(kLibName, RTLD_NOW, &extinfo);
    307   ASSERT_DL_NOTNULL(handle_);
    308   fn f = reinterpret_cast<fn>(dlsym(handle_, "getRandomNumber"));
    309   ASSERT_DL_NOTNULL(f);
    310   EXPECT_GE(reinterpret_cast<void*>(f), start);
    311   EXPECT_LT(reinterpret_cast<void*>(f),
    312             reinterpret_cast<char*>(start) + kLibSize);
    313   EXPECT_EQ(4, f());
    314 
    315   // Check that after dlclose reserved address space is unmapped (and can be reused)
    316   dlclose(handle_);
    317   handle_ = nullptr;
    318 
    319   void* new_start = mmap(start, PAGE_SIZE, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
    320   ASSERT_NE(start, new_start) << "dlclose unmapped reserved space";
    321 }
    322 
    323 TEST_F(DlExtTest, ReservedTooSmall) {
    324   void* start = mmap(nullptr, PAGE_SIZE, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
    325   ASSERT_TRUE(start != MAP_FAILED);
    326   android_dlextinfo extinfo;
    327   extinfo.flags = ANDROID_DLEXT_RESERVED_ADDRESS;
    328   extinfo.reserved_addr = start;
    329   extinfo.reserved_size = PAGE_SIZE;
    330   handle_ = android_dlopen_ext(kLibName, RTLD_NOW, &extinfo);
    331   EXPECT_EQ(nullptr, handle_);
    332 }
    333 
    334 TEST_F(DlExtTest, ReservedHint) {
    335   void* start = mmap(nullptr, kLibSize, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
    336   ASSERT_TRUE(start != MAP_FAILED);
    337   android_dlextinfo extinfo;
    338   extinfo.flags = ANDROID_DLEXT_RESERVED_ADDRESS_HINT;
    339   extinfo.reserved_addr = start;
    340   extinfo.reserved_size = kLibSize;
    341   handle_ = android_dlopen_ext(kLibName, RTLD_NOW, &extinfo);
    342   ASSERT_DL_NOTNULL(handle_);
    343   fn f = reinterpret_cast<fn>(dlsym(handle_, "getRandomNumber"));
    344   ASSERT_DL_NOTNULL(f);
    345   EXPECT_GE(reinterpret_cast<void*>(f), start);
    346   EXPECT_LT(reinterpret_cast<void*>(f),
    347             reinterpret_cast<char*>(start) + kLibSize);
    348   EXPECT_EQ(4, f());
    349 }
    350 
    351 TEST_F(DlExtTest, ReservedHintTooSmall) {
    352   void* start = mmap(nullptr, PAGE_SIZE, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
    353   ASSERT_TRUE(start != MAP_FAILED);
    354   android_dlextinfo extinfo;
    355   extinfo.flags = ANDROID_DLEXT_RESERVED_ADDRESS_HINT;
    356   extinfo.reserved_addr = start;
    357   extinfo.reserved_size = PAGE_SIZE;
    358   handle_ = android_dlopen_ext(kLibName, RTLD_NOW, &extinfo);
    359   ASSERT_DL_NOTNULL(handle_);
    360   fn f = reinterpret_cast<fn>(dlsym(handle_, "getRandomNumber"));
    361   ASSERT_DL_NOTNULL(f);
    362   EXPECT_TRUE(reinterpret_cast<void*>(f) < start ||
    363               (reinterpret_cast<void*>(f) >=
    364                reinterpret_cast<char*>(start) + PAGE_SIZE));
    365   EXPECT_EQ(4, f());
    366 }
    367 
    368 TEST_F(DlExtTest, LoadAtFixedAddress) {
    369   void* start = mmap(nullptr, kLibSize, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
    370   ASSERT_TRUE(start != MAP_FAILED);
    371   munmap(start, kLibSize);
    372 
    373   android_dlextinfo extinfo;
    374   extinfo.flags = ANDROID_DLEXT_LOAD_AT_FIXED_ADDRESS;
    375   extinfo.reserved_addr = start;
    376 
    377   handle_ = android_dlopen_ext(kLibName, RTLD_NOW, &extinfo);
    378   ASSERT_DL_NOTNULL(handle_);
    379   fn f = reinterpret_cast<fn>(dlsym(handle_, "getRandomNumber"));
    380   ASSERT_DL_NOTNULL(f);
    381   EXPECT_GE(reinterpret_cast<void*>(f), start);
    382   EXPECT_LT(reinterpret_cast<void*>(f), reinterpret_cast<char*>(start) + kLibSize);
    383 
    384   EXPECT_EQ(4, f());
    385   dlclose(handle_);
    386   handle_ = nullptr;
    387 
    388   // Check that dlclose unmapped the file
    389   void* addr = mmap(start, kLibSize, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
    390   ASSERT_EQ(start, addr) << "dlclose did not unmap the memory";
    391 }
    392 
    393 TEST_F(DlExtTest, LoadAtFixedAddressTooSmall) {
    394   void* start = mmap(nullptr, kLibSize + PAGE_SIZE, PROT_NONE,
    395                          MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
    396   ASSERT_TRUE(start != MAP_FAILED);
    397   munmap(start, kLibSize + PAGE_SIZE);
    398   void* new_addr = mmap(reinterpret_cast<uint8_t*>(start) + PAGE_SIZE, kLibSize, PROT_NONE,
    399                         MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
    400   ASSERT_TRUE(new_addr != MAP_FAILED);
    401 
    402   android_dlextinfo extinfo;
    403   extinfo.flags = ANDROID_DLEXT_LOAD_AT_FIXED_ADDRESS;
    404   extinfo.reserved_addr = start;
    405 
    406   handle_ = android_dlopen_ext(kLibName, RTLD_NOW, &extinfo);
    407   ASSERT_TRUE(handle_ == nullptr);
    408 }
    409 
    410 class DlExtRelroSharingTest : public DlExtTest {
    411 protected:
    412   virtual void SetUp() {
    413     DlExtTest::SetUp();
    414     void* start = mmap(nullptr, kLibSize, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
    415     ASSERT_TRUE(start != MAP_FAILED);
    416     extinfo_.flags = ANDROID_DLEXT_RESERVED_ADDRESS;
    417     extinfo_.reserved_addr = start;
    418     extinfo_.reserved_size = kLibSize;
    419     extinfo_.relro_fd = -1;
    420   }
    421 
    422   virtual void TearDown() {
    423     DlExtTest::TearDown();
    424   }
    425 
    426   void CreateRelroFile(const char* lib, const char* relro_file) {
    427     int relro_fd = open(relro_file, O_RDWR | O_TRUNC);
    428     ASSERT_NOERROR(relro_fd);
    429 
    430     pid_t pid = fork();
    431     if (pid == 0) {
    432       // child process
    433       extinfo_.flags |= ANDROID_DLEXT_WRITE_RELRO;
    434       extinfo_.relro_fd = relro_fd;
    435       void* handle = android_dlopen_ext(lib, RTLD_NOW, &extinfo_);
    436       if (handle == nullptr) {
    437         fprintf(stderr, "in child: %s\n", dlerror());
    438         exit(1);
    439       }
    440       exit(0);
    441     }
    442 
    443     // continuing in parent
    444     ASSERT_NOERROR(close(relro_fd));
    445     ASSERT_NOERROR(pid);
    446     AssertChildExited(pid, 0);
    447 
    448     // reopen file for reading so it can be used
    449     relro_fd = open(relro_file, O_RDONLY);
    450     ASSERT_NOERROR(relro_fd);
    451     extinfo_.flags |= ANDROID_DLEXT_USE_RELRO;
    452     extinfo_.relro_fd = relro_fd;
    453   }
    454 
    455   void TryUsingRelro(const char* lib) {
    456     handle_ = android_dlopen_ext(lib, RTLD_NOW, &extinfo_);
    457     ASSERT_DL_NOTNULL(handle_);
    458     fn f = reinterpret_cast<fn>(dlsym(handle_, "getRandomNumber"));
    459     ASSERT_DL_NOTNULL(f);
    460     EXPECT_EQ(4, f());
    461 
    462     uint32_t* taxicab_number =
    463             reinterpret_cast<uint32_t*>(dlsym(handle_, "dlopen_testlib_taxicab_number"));
    464     ASSERT_DL_NOTNULL(taxicab_number);
    465     EXPECT_EQ(1729U, *taxicab_number);
    466   }
    467 
    468   void SpawnChildrenAndMeasurePss(const char* lib, const char* relro_file, bool share_relro,
    469                                   size_t* pss_out);
    470 
    471   android_dlextinfo extinfo_;
    472 };
    473 
    474 TEST_F(DlExtRelroSharingTest, ChildWritesGoodData) {
    475   TemporaryFile tf; // Use tf to get an unique filename.
    476   ASSERT_NOERROR(close(tf.fd));
    477 
    478   ASSERT_NO_FATAL_FAILURE(CreateRelroFile(kLibName, tf.filename));
    479   ASSERT_NO_FATAL_FAILURE(TryUsingRelro(kLibName));
    480 
    481   // Use destructor of tf to close and unlink the file.
    482   tf.fd = extinfo_.relro_fd;
    483 }
    484 
    485 TEST_F(DlExtRelroSharingTest, ChildWritesNoRelro) {
    486   TemporaryFile tf; // // Use tf to get an unique filename.
    487   ASSERT_NOERROR(close(tf.fd));
    488 
    489   ASSERT_NO_FATAL_FAILURE(CreateRelroFile(kLibNameNoRelro, tf.filename));
    490   ASSERT_NO_FATAL_FAILURE(TryUsingRelro(kLibNameNoRelro));
    491 
    492   // Use destructor of tf to close and unlink the file.
    493   tf.fd = extinfo_.relro_fd;
    494 }
    495 
    496 TEST_F(DlExtRelroSharingTest, RelroFileEmpty) {
    497   ASSERT_NO_FATAL_FAILURE(TryUsingRelro(kLibName));
    498 }
    499 
    500 TEST_F(DlExtRelroSharingTest, VerifyMemorySaving) {
    501   if (geteuid() != 0) {
    502     GTEST_LOG_(INFO) << "This test must be run as root.\n";
    503     return;
    504   }
    505 
    506   TemporaryFile tf; // Use tf to get an unique filename.
    507   ASSERT_NOERROR(close(tf.fd));
    508 
    509   ASSERT_NO_FATAL_FAILURE(CreateRelroFile(kLibName, tf.filename));
    510 
    511   int pipefd[2];
    512   ASSERT_NOERROR(pipe(pipefd));
    513 
    514   size_t without_sharing, with_sharing;
    515   ASSERT_NO_FATAL_FAILURE(SpawnChildrenAndMeasurePss(kLibName, tf.filename, false, &without_sharing));
    516   ASSERT_NO_FATAL_FAILURE(SpawnChildrenAndMeasurePss(kLibName, tf.filename, true, &with_sharing));
    517   ASSERT_LT(with_sharing, without_sharing);
    518 
    519   // We expect the sharing to save at least 50% of the library's total PSS.
    520   // In practice it saves 80%+ for this library in the test.
    521   size_t pss_saved = without_sharing - with_sharing;
    522   size_t expected_min_saved = without_sharing / 2;
    523 
    524   EXPECT_LT(expected_min_saved, pss_saved);
    525 
    526   // Use destructor of tf to close and unlink the file.
    527   tf.fd = extinfo_.relro_fd;
    528 }
    529 
    530 void GetPss(bool shared_relro, const char* lib, const char* relro_file, pid_t pid,
    531             size_t* total_pss) {
    532   pm_kernel_t* kernel;
    533   ASSERT_EQ(0, pm_kernel_create(&kernel));
    534 
    535   pm_process_t* process;
    536   ASSERT_EQ(0, pm_process_create(kernel, pid, &process));
    537 
    538   pm_map_t** maps;
    539   size_t num_maps;
    540   ASSERT_EQ(0, pm_process_maps(process, &maps, &num_maps));
    541 
    542   // Calculate total PSS of the library.
    543   *total_pss = 0;
    544   bool saw_relro_file = false;
    545   for (size_t i = 0; i < num_maps; ++i) {
    546     if (android::base::EndsWith(maps[i]->name, lib) || strcmp(maps[i]->name, relro_file) == 0) {
    547       if (strcmp(maps[i]->name, relro_file) == 0) saw_relro_file = true;
    548 
    549       pm_memusage_t usage;
    550       ASSERT_EQ(0, pm_map_usage(maps[i], &usage));
    551       *total_pss += usage.pss;
    552     }
    553   }
    554 
    555   free(maps);
    556   pm_process_destroy(process);
    557   pm_kernel_destroy(kernel);
    558 
    559   if (shared_relro) ASSERT_TRUE(saw_relro_file);
    560 }
    561 
    562 void DlExtRelroSharingTest::SpawnChildrenAndMeasurePss(const char* lib, const char* relro_file,
    563                                                        bool share_relro, size_t* pss_out) {
    564   const int CHILDREN = 20;
    565 
    566   // Create children
    567   pid_t child_pids[CHILDREN];
    568   int childpipe[CHILDREN];
    569   for (int i=0; i<CHILDREN; ++i) {
    570     char read_buf;
    571     int child_done_pipe[2], parent_done_pipe[2];
    572     ASSERT_NOERROR(pipe(child_done_pipe));
    573     ASSERT_NOERROR(pipe(parent_done_pipe));
    574 
    575     pid_t child = fork();
    576     if (child == 0) {
    577       // close the 'wrong' ends of the pipes in the child
    578       close(child_done_pipe[0]);
    579       close(parent_done_pipe[1]);
    580 
    581       // open the library
    582       void* handle;
    583       if (share_relro) {
    584         handle = android_dlopen_ext(lib, RTLD_NOW, &extinfo_);
    585       } else {
    586         handle = dlopen(lib, RTLD_NOW);
    587       }
    588       if (handle == nullptr) {
    589         fprintf(stderr, "in child: %s\n", dlerror());
    590         exit(1);
    591       }
    592 
    593       // close write end of child_done_pipe to signal the parent that we're done.
    594       close(child_done_pipe[1]);
    595 
    596       // wait for the parent to close parent_done_pipe, then exit
    597       read(parent_done_pipe[0], &read_buf, 1);
    598       exit(0);
    599     }
    600 
    601     ASSERT_NOERROR(child);
    602 
    603     // close the 'wrong' ends of the pipes in the parent
    604     close(child_done_pipe[1]);
    605     close(parent_done_pipe[0]);
    606 
    607     // wait for the child to be done
    608     read(child_done_pipe[0], &read_buf, 1);
    609     close(child_done_pipe[0]);
    610 
    611     // save the child's pid and the parent_done_pipe
    612     child_pids[i] = child;
    613     childpipe[i] = parent_done_pipe[1];
    614   }
    615 
    616   // Sum the PSS of tested library of all the children
    617   size_t total_pss = 0;
    618   for (int i=0; i<CHILDREN; ++i) {
    619     size_t child_pss;
    620     ASSERT_NO_FATAL_FAILURE(GetPss(share_relro, lib, relro_file, child_pids[i], &child_pss));
    621     total_pss += child_pss;
    622   }
    623   *pss_out = total_pss;
    624 
    625   // Close pipes and wait for children to exit
    626   for (int i=0; i<CHILDREN; ++i) {
    627     ASSERT_NOERROR(close(childpipe[i]));
    628   }
    629   for (int i = 0; i < CHILDREN; ++i) {
    630     AssertChildExited(child_pids[i], 0);
    631   }
    632 }
    633 
    634 // Testing namespaces
    635 static const char* g_public_lib = "libnstest_public.so";
    636 
    637 // These are libs shared with default namespace
    638 static const std::string g_core_shared_libs = "libc.so:libc++.so:libdl.so:libm.so";
    639 
    640 TEST(dlext, ns_smoke) {
    641   static const char* root_lib = "libnstest_root.so";
    642   std::string shared_libs = g_core_shared_libs + ":" + g_public_lib;
    643 
    644   ASSERT_FALSE(android_init_anonymous_namespace("", nullptr));
    645   ASSERT_STREQ("android_init_anonymous_namespace failed: error linking namespaces"
    646                " \"(anonymous)\"->\"(default)\": the list of shared libraries is empty.",
    647                dlerror());
    648 
    649   const std::string lib_public_path = get_testlib_root() + "/public_namespace_libs/" + g_public_lib;
    650   void* handle_public = dlopen(lib_public_path.c_str(), RTLD_NOW);
    651   ASSERT_TRUE(handle_public != nullptr) << dlerror();
    652 
    653   ASSERT_TRUE(android_init_anonymous_namespace(shared_libs.c_str(), nullptr)) << dlerror();
    654 
    655   // Check that libraries added to public namespace are not NODELETE
    656   dlclose(handle_public);
    657   handle_public = dlopen(lib_public_path.c_str(), RTLD_NOW | RTLD_NOLOAD);
    658   ASSERT_TRUE(handle_public == nullptr);
    659   ASSERT_EQ(std::string("dlopen failed: library \"") + lib_public_path +
    660                "\" wasn't loaded and RTLD_NOLOAD prevented it", dlerror());
    661 
    662   handle_public = dlopen(lib_public_path.c_str(), RTLD_NOW);
    663 
    664   // create "public namespace", share limited set of public libraries with
    665 
    666   android_namespace_t* ns1 =
    667           android_create_namespace("private",
    668                                    nullptr,
    669                                    (get_testlib_root() + "/private_namespace_libs").c_str(),
    670                                    ANDROID_NAMESPACE_TYPE_REGULAR,
    671                                    nullptr,
    672                                    nullptr);
    673   ASSERT_TRUE(ns1 != nullptr) << dlerror();
    674   ASSERT_TRUE(android_link_namespaces(ns1, nullptr, shared_libs.c_str())) << dlerror();
    675 
    676   android_namespace_t* ns2 =
    677           android_create_namespace("private_isolated",
    678                                    nullptr,
    679                                    (get_testlib_root() + "/private_namespace_libs").c_str(),
    680                                    ANDROID_NAMESPACE_TYPE_ISOLATED,
    681                                    nullptr,
    682                                    nullptr);
    683   ASSERT_TRUE(ns2 != nullptr) << dlerror();
    684   ASSERT_TRUE(android_link_namespaces(ns2, nullptr, shared_libs.c_str())) << dlerror();
    685 
    686   // This should not have affect search path for default namespace:
    687   ASSERT_TRUE(dlopen(root_lib, RTLD_NOW) == nullptr);
    688   void* handle = dlopen(g_public_lib, RTLD_NOW);
    689   ASSERT_TRUE(handle != nullptr) << dlerror();
    690   dlclose(handle);
    691 
    692   // dlopen for a public library using an absolute path should work
    693   // 1. For isolated namespaces
    694   android_dlextinfo extinfo;
    695   extinfo.flags = ANDROID_DLEXT_USE_NAMESPACE;
    696   extinfo.library_namespace = ns2;
    697   handle = android_dlopen_ext(lib_public_path.c_str(), RTLD_NOW, &extinfo);
    698   ASSERT_TRUE(handle != nullptr) << dlerror();
    699   ASSERT_TRUE(handle == handle_public);
    700 
    701   dlclose(handle);
    702 
    703   // 1.1 even if it wasn't loaded before
    704   dlclose(handle_public);
    705 
    706   handle_public = dlopen(lib_public_path.c_str(), RTLD_NOW | RTLD_NOLOAD);
    707   ASSERT_TRUE(handle_public == nullptr);
    708   ASSERT_EQ(std::string("dlopen failed: library \"") + lib_public_path +
    709                "\" wasn't loaded and RTLD_NOLOAD prevented it", dlerror());
    710 
    711   handle = android_dlopen_ext(lib_public_path.c_str(), RTLD_NOW, &extinfo);
    712   ASSERT_TRUE(handle != nullptr) << dlerror();
    713 
    714   handle_public = dlopen(lib_public_path.c_str(), RTLD_NOW);
    715   ASSERT_TRUE(handle == handle_public);
    716 
    717   dlclose(handle);
    718 
    719   // 2. And for regular namespaces (make sure it does not load second copy of the library)
    720   extinfo.library_namespace = ns1;
    721   handle = android_dlopen_ext(lib_public_path.c_str(), RTLD_NOW, &extinfo);
    722   ASSERT_TRUE(handle != nullptr) << dlerror();
    723   ASSERT_TRUE(handle == handle_public);
    724 
    725   dlclose(handle);
    726 
    727   // 2.1 Unless it was not loaded before - in which case it will load a duplicate.
    728   // TODO(dimitry): This is broken. Maybe we need to deprecate non-isolated namespaces?
    729   dlclose(handle_public);
    730 
    731   handle_public = dlopen(lib_public_path.c_str(), RTLD_NOW | RTLD_NOLOAD);
    732   ASSERT_TRUE(handle_public == nullptr);
    733   ASSERT_EQ(std::string("dlopen failed: library \"") + lib_public_path +
    734                "\" wasn't loaded and RTLD_NOLOAD prevented it", dlerror());
    735 
    736   handle = android_dlopen_ext(lib_public_path.c_str(), RTLD_NOW, &extinfo);
    737   ASSERT_TRUE(handle != nullptr) << dlerror();
    738 
    739   handle_public = dlopen(lib_public_path.c_str(), RTLD_NOW);
    740 
    741   ASSERT_TRUE(handle != handle_public);
    742 
    743   dlclose(handle);
    744 
    745   extinfo.library_namespace = ns1;
    746 
    747   void* handle1 = android_dlopen_ext(root_lib, RTLD_NOW, &extinfo);
    748   ASSERT_TRUE(handle1 != nullptr) << dlerror();
    749 
    750   extinfo.library_namespace = ns2;
    751   void* handle2 = android_dlopen_ext(root_lib, RTLD_NOW, &extinfo);
    752   ASSERT_TRUE(handle2 != nullptr) << dlerror();
    753 
    754   ASSERT_TRUE(handle1 != handle2);
    755 
    756   typedef const char* (*fn_t)();
    757 
    758   fn_t ns_get_local_string1 = reinterpret_cast<fn_t>(dlsym(handle1, "ns_get_local_string"));
    759   ASSERT_TRUE(ns_get_local_string1 != nullptr) << dlerror();
    760   fn_t ns_get_local_string2 = reinterpret_cast<fn_t>(dlsym(handle2, "ns_get_local_string"));
    761   ASSERT_TRUE(ns_get_local_string2 != nullptr) << dlerror();
    762 
    763   EXPECT_STREQ("This string is local to root library", ns_get_local_string1());
    764   EXPECT_STREQ("This string is local to root library", ns_get_local_string2());
    765 
    766   ASSERT_TRUE(ns_get_local_string1() != ns_get_local_string2());
    767 
    768   fn_t ns_get_private_extern_string1 =
    769           reinterpret_cast<fn_t>(dlsym(handle1, "ns_get_private_extern_string"));
    770   ASSERT_TRUE(ns_get_private_extern_string1 != nullptr) << dlerror();
    771   fn_t ns_get_private_extern_string2 =
    772           reinterpret_cast<fn_t>(dlsym(handle2, "ns_get_private_extern_string"));
    773   ASSERT_TRUE(ns_get_private_extern_string2 != nullptr) << dlerror();
    774 
    775   EXPECT_STREQ("This string is from private namespace", ns_get_private_extern_string1());
    776   EXPECT_STREQ("This string is from private namespace", ns_get_private_extern_string2());
    777 
    778   ASSERT_TRUE(ns_get_private_extern_string1() != ns_get_private_extern_string2());
    779 
    780   fn_t ns_get_public_extern_string1 =
    781           reinterpret_cast<fn_t>(dlsym(handle1, "ns_get_public_extern_string"));
    782   ASSERT_TRUE(ns_get_public_extern_string1 != nullptr) << dlerror();
    783   fn_t ns_get_public_extern_string2 =
    784           reinterpret_cast<fn_t>(dlsym(handle2, "ns_get_public_extern_string"));
    785   ASSERT_TRUE(ns_get_public_extern_string2 != nullptr) << dlerror();
    786 
    787   EXPECT_STREQ("This string is from public namespace", ns_get_public_extern_string1());
    788   ASSERT_TRUE(ns_get_public_extern_string1() == ns_get_public_extern_string2());
    789 
    790   // and now check that dlopen() does the right thing in terms of preserving namespace
    791   fn_t ns_get_dlopened_string1 = reinterpret_cast<fn_t>(dlsym(handle1, "ns_get_dlopened_string"));
    792   ASSERT_TRUE(ns_get_dlopened_string1 != nullptr) << dlerror();
    793   fn_t ns_get_dlopened_string2 = reinterpret_cast<fn_t>(dlsym(handle2, "ns_get_dlopened_string"));
    794   ASSERT_TRUE(ns_get_dlopened_string2 != nullptr) << dlerror();
    795 
    796   EXPECT_STREQ("This string is from private namespace (dlopened library)", ns_get_dlopened_string1());
    797   EXPECT_STREQ("This string is from private namespace (dlopened library)", ns_get_dlopened_string2());
    798 
    799   ASSERT_TRUE(ns_get_dlopened_string1() != ns_get_dlopened_string2());
    800 
    801   // Check that symbols from non-shared libraries a shared library depends on are not visible
    802   // from original namespace.
    803 
    804   fn_t ns_get_internal_extern_string =
    805           reinterpret_cast<fn_t>(dlsym(handle1, "ns_get_internal_extern_string"));
    806   ASSERT_TRUE(ns_get_internal_extern_string != nullptr) << dlerror();
    807   ASSERT_TRUE(ns_get_internal_extern_string() == nullptr) <<
    808       "ns_get_internal_extern_string() expected to return null but returns \"" <<
    809       ns_get_internal_extern_string() << "\"";
    810 
    811   dlclose(handle1);
    812 
    813   // Check if handle2 is still alive (and well)
    814   ASSERT_STREQ("This string is local to root library", ns_get_local_string2());
    815   ASSERT_STREQ("This string is from private namespace", ns_get_private_extern_string2());
    816   ASSERT_STREQ("This string is from public namespace", ns_get_public_extern_string2());
    817   ASSERT_STREQ("This string is from private namespace (dlopened library)", ns_get_dlopened_string2());
    818 
    819   dlclose(handle2);
    820 }
    821 
    822 TEST(dlext, dlopen_ext_use_o_tmpfile_fd) {
    823   const std::string lib_path = get_testlib_root() + "/libtest_simple.so";
    824 
    825   int tmpfd = TEMP_FAILURE_RETRY(
    826         open(get_testlib_root().c_str(), O_TMPFILE | O_CLOEXEC | O_RDWR | O_EXCL));
    827 
    828   // Ignore kernels without O_TMPFILE flag support
    829   if (tmpfd == -1 && (errno == EISDIR || errno == EINVAL || errno == EOPNOTSUPP)) {
    830     return;
    831   }
    832 
    833   ASSERT_TRUE(tmpfd != -1) << strerror(errno);
    834 
    835   android_namespace_t* ns =
    836           android_create_namespace("testing-o_tmpfile",
    837                                    nullptr,
    838                                    get_testlib_root().c_str(),
    839                                    ANDROID_NAMESPACE_TYPE_ISOLATED,
    840                                    nullptr,
    841                                    nullptr);
    842 
    843   ASSERT_DL_NOTNULL(ns);
    844 
    845   ASSERT_TRUE(android_link_namespaces(ns, nullptr, g_core_shared_libs.c_str())) << dlerror();
    846 
    847   std::string content;
    848   ASSERT_TRUE(android::base::ReadFileToString(lib_path, &content)) << strerror(errno);
    849   ASSERT_TRUE(android::base::WriteStringToFd(content, tmpfd)) << strerror(errno);
    850 
    851   android_dlextinfo extinfo;
    852   extinfo.flags = ANDROID_DLEXT_USE_LIBRARY_FD | ANDROID_DLEXT_USE_NAMESPACE;
    853   extinfo.library_fd = tmpfd;
    854   extinfo.library_namespace = ns;
    855 
    856   void* handle = android_dlopen_ext("foobar", RTLD_NOW, &extinfo);
    857 
    858   ASSERT_DL_NOTNULL(handle);
    859 
    860   uint32_t* taxicab_number = reinterpret_cast<uint32_t*>(dlsym(handle, "dlopen_testlib_taxicab_number"));
    861   ASSERT_DL_NOTNULL(taxicab_number);
    862   EXPECT_EQ(1729U, *taxicab_number);
    863   dlclose(handle);
    864 }
    865 
    866 TEST(dlext, dlopen_ext_use_memfd) {
    867   const std::string lib_path = get_testlib_root() + "/libtest_simple.so";
    868 
    869   // create memfd
    870   int memfd = syscall(__NR_memfd_create, "foobar", MFD_CLOEXEC);
    871   if (memfd == -1 && errno == ENOSYS) {
    872     return;
    873   }
    874 
    875   ASSERT_TRUE(memfd != -1) << strerror(errno);
    876 
    877   // Check st.f_type is TMPFS_MAGIC for memfd
    878   struct statfs st;
    879   ASSERT_TRUE(TEMP_FAILURE_RETRY(fstatfs(memfd, &st)) == 0) << strerror(errno);
    880   ASSERT_EQ(static_cast<decltype(st.f_type)>(TMPFS_MAGIC), st.f_type);
    881 
    882   android_namespace_t* ns =
    883           android_create_namespace("testing-memfd",
    884                                    nullptr,
    885                                    get_testlib_root().c_str(),
    886                                    ANDROID_NAMESPACE_TYPE_ISOLATED,
    887                                    nullptr,
    888                                    nullptr);
    889 
    890   ASSERT_DL_NOTNULL(ns);
    891 
    892   ASSERT_TRUE(android_link_namespaces(ns, nullptr, g_core_shared_libs.c_str())) << dlerror();
    893 
    894   // read file into memfd backed one.
    895   std::string content;
    896   ASSERT_TRUE(android::base::ReadFileToString(lib_path, &content)) << strerror(errno);
    897   ASSERT_TRUE(android::base::WriteStringToFd(content, memfd)) << strerror(errno);
    898 
    899   android_dlextinfo extinfo;
    900   extinfo.flags = ANDROID_DLEXT_USE_LIBRARY_FD | ANDROID_DLEXT_USE_NAMESPACE;
    901   extinfo.library_fd = memfd;
    902   extinfo.library_namespace = ns;
    903 
    904   void* handle = android_dlopen_ext("foobar", RTLD_NOW, &extinfo);
    905 
    906   ASSERT_DL_NOTNULL(handle);
    907 
    908   uint32_t* taxicab_number = reinterpret_cast<uint32_t*>(dlsym(handle, "dlopen_testlib_taxicab_number"));
    909   ASSERT_DL_NOTNULL(taxicab_number);
    910   EXPECT_EQ(1729U, *taxicab_number);
    911   dlclose(handle);
    912 }
    913 
    914 TEST(dlext, ns_symbol_visibilty_one_namespace) {
    915   static const char* root_lib = "libnstest_root.so";
    916   ASSERT_TRUE(android_init_anonymous_namespace(g_core_shared_libs.c_str(), nullptr));
    917 
    918   const std::string ns_search_path = get_testlib_root() + "/public_namespace_libs:" +
    919                                      get_testlib_root() + "/private_namespace_libs";
    920 
    921   android_namespace_t* ns =
    922           android_create_namespace("one",
    923                                    nullptr,
    924                                    ns_search_path.c_str(),
    925                                    ANDROID_NAMESPACE_TYPE_ISOLATED,
    926                                    nullptr,
    927                                    nullptr);
    928 
    929   ASSERT_TRUE(android_link_namespaces(ns, nullptr, g_core_shared_libs.c_str())) << dlerror();
    930 
    931   android_dlextinfo extinfo;
    932   extinfo.flags = ANDROID_DLEXT_USE_NAMESPACE;
    933   extinfo.library_namespace = ns;
    934 
    935   void* handle = android_dlopen_ext(root_lib, RTLD_NOW, &extinfo);
    936   ASSERT_TRUE(handle != nullptr) << dlerror();
    937 
    938   typedef const char* (*fn_t)();
    939 
    940   // Check that relocation worked correctly
    941   fn_t ns_get_internal_extern_string =
    942           reinterpret_cast<fn_t>(dlsym(handle, "ns_get_internal_extern_string"));
    943   ASSERT_TRUE(ns_get_internal_extern_string != nullptr) << dlerror();
    944   ASSERT_STREQ("This string is from a library a shared library depends on", ns_get_internal_extern_string());
    945 
    946   fn_t internal_extern_string_fn =
    947           reinterpret_cast<fn_t>(dlsym(handle, "internal_extern_string"));
    948   ASSERT_TRUE(internal_extern_string_fn != nullptr) << dlerror();
    949   ASSERT_STREQ("This string is from a library a shared library depends on", internal_extern_string_fn());
    950 }
    951 
    952 TEST(dlext, ns_symbol_visibilty_between_namespaces) {
    953   static const char* root_lib = "libnstest_root.so";
    954   ASSERT_TRUE(android_init_anonymous_namespace(g_core_shared_libs.c_str(), nullptr));
    955 
    956   const std::string public_ns_search_path =  get_testlib_root() + "/public_namespace_libs";
    957   const std::string private_ns_search_path = get_testlib_root() + "/private_namespace_libs";
    958 
    959   android_namespace_t* ns_public =
    960           android_create_namespace("public",
    961                                    nullptr,
    962                                    public_ns_search_path.c_str(),
    963                                    ANDROID_NAMESPACE_TYPE_ISOLATED,
    964                                    nullptr,
    965                                    nullptr);
    966 
    967   ASSERT_TRUE(android_link_namespaces(ns_public, nullptr, g_core_shared_libs.c_str())) << dlerror();
    968 
    969   android_namespace_t* ns_private =
    970           android_create_namespace("private",
    971                                    nullptr,
    972                                    private_ns_search_path.c_str(),
    973                                    ANDROID_NAMESPACE_TYPE_ISOLATED,
    974                                    nullptr,
    975                                    nullptr);
    976 
    977   ASSERT_TRUE(android_link_namespaces(ns_private, ns_public, g_public_lib)) << dlerror();
    978   ASSERT_TRUE(android_link_namespaces(ns_private, nullptr, g_core_shared_libs.c_str())) << dlerror();
    979 
    980   android_dlextinfo extinfo;
    981   extinfo.flags = ANDROID_DLEXT_USE_NAMESPACE;
    982   extinfo.library_namespace = ns_private;
    983 
    984   void* handle = android_dlopen_ext(root_lib, RTLD_NOW, &extinfo);
    985   ASSERT_TRUE(handle != nullptr) << dlerror();
    986 
    987   typedef const char* (*fn_t)();
    988 
    989   // Check that relocation worked correctly
    990   fn_t ns_get_internal_extern_string =
    991           reinterpret_cast<fn_t>(dlsym(handle, "ns_get_internal_extern_string"));
    992   ASSERT_TRUE(ns_get_internal_extern_string != nullptr) << dlerror();
    993   ASSERT_TRUE(ns_get_internal_extern_string() == nullptr) <<
    994       "ns_get_internal_extern_string() expected to return null but returns \"" <<
    995       ns_get_internal_extern_string() << "\"";
    996 
    997   fn_t internal_extern_string_fn =
    998           reinterpret_cast<fn_t>(dlsym(handle, "internal_extern_string"));
    999   ASSERT_TRUE(internal_extern_string_fn == nullptr);
   1000   ASSERT_STREQ("undefined symbol: internal_extern_string", dlerror());
   1001 }
   1002 
   1003 TEST(dlext, ns_unload_between_namespaces) {
   1004   static const char* root_lib = "libnstest_root.so";
   1005   ASSERT_TRUE(android_init_anonymous_namespace(g_core_shared_libs.c_str(), nullptr));
   1006 
   1007   const std::string public_ns_search_path =  get_testlib_root() + "/public_namespace_libs";
   1008   const std::string private_ns_search_path = get_testlib_root() + "/private_namespace_libs";
   1009 
   1010   android_namespace_t* ns_public =
   1011           android_create_namespace("public",
   1012                                    nullptr,
   1013                                    public_ns_search_path.c_str(),
   1014                                    ANDROID_NAMESPACE_TYPE_ISOLATED,
   1015                                    nullptr,
   1016                                    nullptr);
   1017 
   1018   ASSERT_TRUE(android_link_namespaces(ns_public, nullptr, g_core_shared_libs.c_str())) << dlerror();
   1019 
   1020   android_namespace_t* ns_private =
   1021           android_create_namespace("private",
   1022                                    nullptr,
   1023                                    private_ns_search_path.c_str(),
   1024                                    ANDROID_NAMESPACE_TYPE_ISOLATED,
   1025                                    nullptr,
   1026                                    nullptr);
   1027 
   1028   ASSERT_TRUE(android_link_namespaces(ns_private, ns_public, g_public_lib)) << dlerror();
   1029   ASSERT_TRUE(android_link_namespaces(ns_private, nullptr, g_core_shared_libs.c_str())) << dlerror();
   1030 
   1031   android_dlextinfo extinfo;
   1032   extinfo.flags = ANDROID_DLEXT_USE_NAMESPACE;
   1033   extinfo.library_namespace = ns_private;
   1034 
   1035   void* handle = android_dlopen_ext(root_lib, RTLD_NOW, &extinfo);
   1036   ASSERT_TRUE(handle != nullptr) << dlerror();
   1037 
   1038   dlclose(handle);
   1039   // Check that root_lib was unloaded
   1040   handle = android_dlopen_ext(root_lib, RTLD_NOW | RTLD_NOLOAD, &extinfo);
   1041   ASSERT_TRUE(handle == nullptr);
   1042   ASSERT_EQ(std::string("dlopen failed: library \"") + root_lib +
   1043             "\" wasn't loaded and RTLD_NOLOAD prevented it", dlerror());
   1044 
   1045   // Check that shared library was unloaded in public ns
   1046   extinfo.library_namespace = ns_public;
   1047   handle = android_dlopen_ext(g_public_lib, RTLD_NOW | RTLD_NOLOAD, &extinfo);
   1048   ASSERT_TRUE(handle == nullptr);
   1049   ASSERT_EQ(std::string("dlopen failed: library \"") + g_public_lib +
   1050             "\" wasn't loaded and RTLD_NOLOAD prevented it", dlerror());
   1051 }
   1052 
   1053 TEST(dlext, ns_greylist_enabled) {
   1054   ASSERT_TRUE(android_init_anonymous_namespace(g_core_shared_libs.c_str(), nullptr));
   1055 
   1056   const std::string ns_search_path = get_testlib_root() + "/private_namespace_libs";
   1057 
   1058   android_namespace_t* ns =
   1059           android_create_namespace("namespace",
   1060                                    nullptr,
   1061                                    ns_search_path.c_str(),
   1062                                    ANDROID_NAMESPACE_TYPE_ISOLATED | ANDROID_NAMESPACE_TYPE_GREYLIST_ENABLED,
   1063                                    nullptr,
   1064                                    nullptr);
   1065 
   1066   ASSERT_TRUE(android_link_namespaces(ns, nullptr, g_core_shared_libs.c_str())) << dlerror();
   1067 
   1068   android_dlextinfo extinfo;
   1069   extinfo.flags = ANDROID_DLEXT_USE_NAMESPACE;
   1070   extinfo.library_namespace = ns;
   1071 
   1072   // An app targeting M can open libnativehelper.so because it's on the greylist.
   1073   android_set_application_target_sdk_version(__ANDROID_API_M__);
   1074   void* handle = android_dlopen_ext("libnativehelper.so", RTLD_NOW, &extinfo);
   1075   ASSERT_TRUE(handle != nullptr) << dlerror();
   1076 
   1077   // Check that loader did not load another copy of libdl.so while loading greylisted library.
   1078   void* dlsym_ptr = dlsym(handle, "dlsym");
   1079   ASSERT_TRUE(dlsym_ptr != nullptr) << dlerror();
   1080   ASSERT_EQ(&dlsym, dlsym_ptr);
   1081 
   1082   dlclose(handle);
   1083 
   1084   // An app targeting N no longer has the greylist.
   1085   android_set_application_target_sdk_version(__ANDROID_API_N__);
   1086   handle = android_dlopen_ext("libnativehelper.so", RTLD_NOW, &extinfo);
   1087   ASSERT_TRUE(handle == nullptr);
   1088   ASSERT_STREQ("dlopen failed: library \"libnativehelper.so\" not found", dlerror());
   1089 }
   1090 
   1091 TEST(dlext, ns_greylist_disabled_by_default) {
   1092   ASSERT_TRUE(android_init_anonymous_namespace(g_core_shared_libs.c_str(), nullptr));
   1093 
   1094   const std::string ns_search_path = get_testlib_root() + "/private_namespace_libs";
   1095 
   1096   android_namespace_t* ns =
   1097           android_create_namespace("namespace",
   1098                                    nullptr,
   1099                                    ns_search_path.c_str(),
   1100                                    ANDROID_NAMESPACE_TYPE_ISOLATED,
   1101                                    nullptr,
   1102                                    nullptr);
   1103 
   1104   ASSERT_TRUE(android_link_namespaces(ns, nullptr, g_core_shared_libs.c_str())) << dlerror();
   1105 
   1106   android_dlextinfo extinfo;
   1107   extinfo.flags = ANDROID_DLEXT_USE_NAMESPACE;
   1108   extinfo.library_namespace = ns;
   1109 
   1110   android_set_application_target_sdk_version(__ANDROID_API_M__);
   1111   void* handle = android_dlopen_ext("libnativehelper.so", RTLD_NOW, &extinfo);
   1112   ASSERT_TRUE(handle == nullptr);
   1113   ASSERT_STREQ("dlopen failed: library \"libnativehelper.so\" not found", dlerror());
   1114 }
   1115 
   1116 TEST(dlext, ns_cyclic_namespaces) {
   1117   // Test that ns1->ns2->ns1 link does not break the loader
   1118   ASSERT_TRUE(android_init_anonymous_namespace(g_core_shared_libs.c_str(), nullptr));
   1119   std::string shared_libs = g_core_shared_libs + ":libthatdoesnotexist.so";
   1120 
   1121   const std::string ns_search_path =  get_testlib_root() + "/public_namespace_libs";
   1122 
   1123   android_namespace_t* ns1 =
   1124           android_create_namespace("ns1",
   1125                                    nullptr,
   1126                                    ns_search_path.c_str(),
   1127                                    ANDROID_NAMESPACE_TYPE_ISOLATED,
   1128                                    nullptr,
   1129                                    nullptr);
   1130 
   1131   ASSERT_TRUE(android_link_namespaces(ns1, nullptr, g_core_shared_libs.c_str())) << dlerror();
   1132 
   1133   android_namespace_t* ns2 =
   1134           android_create_namespace("ns1",
   1135                                    nullptr,
   1136                                    ns_search_path.c_str(),
   1137                                    ANDROID_NAMESPACE_TYPE_ISOLATED,
   1138                                    nullptr,
   1139                                    nullptr);
   1140 
   1141   ASSERT_TRUE(android_link_namespaces(ns2, nullptr, g_core_shared_libs.c_str())) << dlerror();
   1142 
   1143   ASSERT_TRUE(android_link_namespaces(ns2, ns1, shared_libs.c_str())) << dlerror();
   1144   ASSERT_TRUE(android_link_namespaces(ns1, ns2, shared_libs.c_str())) << dlerror();
   1145 
   1146   android_dlextinfo extinfo;
   1147   extinfo.flags = ANDROID_DLEXT_USE_NAMESPACE;
   1148   extinfo.library_namespace = ns1;
   1149 
   1150   void* handle = android_dlopen_ext("libthatdoesnotexist.so", RTLD_NOW, &extinfo);
   1151   ASSERT_TRUE(handle == nullptr);
   1152   ASSERT_STREQ("dlopen failed: library \"libthatdoesnotexist.so\" not found", dlerror());
   1153 }
   1154 
   1155 TEST(dlext, ns_isolated) {
   1156   static const char* root_lib = "libnstest_root_not_isolated.so";
   1157   std::string shared_libs = g_core_shared_libs + ":" + g_public_lib;
   1158 
   1159   const std::string lib_public_path = get_testlib_root() + "/public_namespace_libs/" + g_public_lib;
   1160   void* handle_public = dlopen(lib_public_path.c_str(), RTLD_NOW);
   1161   ASSERT_TRUE(handle_public != nullptr) << dlerror();
   1162 
   1163   android_set_application_target_sdk_version(42U); // something > 23
   1164 
   1165   ASSERT_TRUE(android_init_anonymous_namespace(shared_libs.c_str(), nullptr)) << dlerror();
   1166 
   1167   android_namespace_t* ns_not_isolated =
   1168           android_create_namespace("private",
   1169                                    nullptr,
   1170                                    (get_testlib_root() + "/private_namespace_libs").c_str(),
   1171                                    ANDROID_NAMESPACE_TYPE_REGULAR,
   1172                                    nullptr,
   1173                                    nullptr);
   1174   ASSERT_TRUE(ns_not_isolated != nullptr) << dlerror();
   1175   ASSERT_TRUE(android_link_namespaces(ns_not_isolated, nullptr, shared_libs.c_str())) << dlerror();
   1176 
   1177   android_namespace_t* ns_isolated =
   1178           android_create_namespace("private_isolated1",
   1179                                    nullptr,
   1180                                    (get_testlib_root() + "/private_namespace_libs").c_str(),
   1181                                    ANDROID_NAMESPACE_TYPE_ISOLATED,
   1182                                    nullptr,
   1183                                    nullptr);
   1184   ASSERT_TRUE(ns_isolated != nullptr) << dlerror();
   1185   ASSERT_TRUE(android_link_namespaces(ns_isolated, nullptr, shared_libs.c_str())) << dlerror();
   1186 
   1187   android_namespace_t* ns_isolated2 =
   1188           android_create_namespace("private_isolated2",
   1189                                    (get_testlib_root() + "/private_namespace_libs").c_str(),
   1190                                    nullptr,
   1191                                    ANDROID_NAMESPACE_TYPE_ISOLATED,
   1192                                    get_testlib_root().c_str(),
   1193                                    nullptr);
   1194   ASSERT_TRUE(ns_isolated2 != nullptr) << dlerror();
   1195   ASSERT_TRUE(android_link_namespaces(ns_isolated2, nullptr, shared_libs.c_str())) << dlerror();
   1196 
   1197   ASSERT_TRUE(dlopen(root_lib, RTLD_NOW) == nullptr);
   1198   ASSERT_STREQ("dlopen failed: library \"libnstest_root_not_isolated.so\" not found", dlerror());
   1199 
   1200   std::string lib_private_external_path =
   1201       get_testlib_root() + "/private_namespace_libs_external/libnstest_private_external.so";
   1202 
   1203   // Load lib_private_external_path to default namespace
   1204   // (it should remain invisible for the isolated namespaces after this)
   1205   void* handle = dlopen(lib_private_external_path.c_str(), RTLD_NOW);
   1206   ASSERT_TRUE(handle != nullptr) << dlerror();
   1207 
   1208   android_dlextinfo extinfo;
   1209   extinfo.flags = ANDROID_DLEXT_USE_NAMESPACE;
   1210   extinfo.library_namespace = ns_not_isolated;
   1211 
   1212   void* handle1 = android_dlopen_ext(root_lib, RTLD_NOW, &extinfo);
   1213   ASSERT_TRUE(handle1 != nullptr) << dlerror();
   1214 
   1215   extinfo.library_namespace = ns_isolated;
   1216 
   1217   void* handle2 = android_dlopen_ext(root_lib, RTLD_NOW, &extinfo);
   1218   ASSERT_TRUE(handle2 == nullptr);
   1219   ASSERT_STREQ("dlopen failed: library \"libnstest_private_external.so\" not found", dlerror());
   1220 
   1221   // Check dlopen by absolute path
   1222   handle2 = android_dlopen_ext(lib_private_external_path.c_str(), RTLD_NOW, &extinfo);
   1223   ASSERT_TRUE(handle2 == nullptr);
   1224   ASSERT_EQ("dlopen failed: library \"" + lib_private_external_path + "\" needed"
   1225             " or dlopened by \"" + get_executable_path() +  "\" is not accessible"
   1226             " for the namespace \"private_isolated1\"", dlerror());
   1227 
   1228   extinfo.library_namespace = ns_isolated2;
   1229 
   1230   // this should work because isolation_path for private_isolated2 includes get_testlib_root()
   1231   handle2 = android_dlopen_ext(root_lib, RTLD_NOW, &extinfo);
   1232   ASSERT_TRUE(handle2 != nullptr) << dlerror();
   1233   dlclose(handle2);
   1234 
   1235   // Check dlopen by absolute path
   1236   handle2 = android_dlopen_ext(lib_private_external_path.c_str(), RTLD_NOW, &extinfo);
   1237   ASSERT_TRUE(handle2 != nullptr) << dlerror();
   1238   dlclose(handle2);
   1239 
   1240   typedef const char* (*fn_t)();
   1241   fn_t ns_get_local_string = reinterpret_cast<fn_t>(dlsym(handle1, "ns_get_local_string"));
   1242   ASSERT_TRUE(ns_get_local_string != nullptr) << dlerror();
   1243 
   1244   ASSERT_STREQ("This string is local to root library", ns_get_local_string());
   1245 
   1246   fn_t ns_get_private_extern_string =
   1247           reinterpret_cast<fn_t>(dlsym(handle1, "ns_get_private_extern_string"));
   1248   ASSERT_TRUE(ns_get_private_extern_string != nullptr) << dlerror();
   1249 
   1250   ASSERT_STREQ("This string is from private namespace", ns_get_private_extern_string());
   1251 
   1252   fn_t ns_get_public_extern_string =
   1253           reinterpret_cast<fn_t>(dlsym(handle1, "ns_get_public_extern_string"));
   1254   ASSERT_TRUE(ns_get_public_extern_string != nullptr) << dlerror();
   1255 
   1256   ASSERT_STREQ("This string is from public namespace", ns_get_public_extern_string());
   1257 
   1258   fn_t ns_get_dlopened_string = reinterpret_cast<fn_t>(dlsym(handle1, "ns_get_dlopened_string"));
   1259   ASSERT_TRUE(ns_get_dlopened_string != nullptr) << dlerror();
   1260 
   1261   ASSERT_STREQ("This string is from private namespace (dlopened library)", ns_get_dlopened_string());
   1262 
   1263   dlclose(handle1);
   1264 }
   1265 
   1266 TEST(dlext, ns_shared) {
   1267   static const char* root_lib = "libnstest_root_not_isolated.so";
   1268   static const char* root_lib_isolated = "libnstest_root.so";
   1269 
   1270   std::string shared_libs = g_core_shared_libs + ":" + g_public_lib;
   1271 
   1272   const std::string lib_public_path = get_testlib_root() + "/public_namespace_libs/" + g_public_lib;
   1273   void* handle_public = dlopen(lib_public_path.c_str(), RTLD_NOW);
   1274   ASSERT_TRUE(handle_public != nullptr) << dlerror();
   1275 
   1276   android_set_application_target_sdk_version(42U); // something > 23
   1277 
   1278   ASSERT_TRUE(android_init_anonymous_namespace(shared_libs.c_str(), nullptr)) << dlerror();
   1279 
   1280   // preload this library to the default namespace to check if it
   1281   // is shared later on.
   1282   void* handle_dlopened =
   1283           dlopen((get_testlib_root() + "/private_namespace_libs/libnstest_dlopened.so").c_str(), RTLD_NOW);
   1284   ASSERT_TRUE(handle_dlopened != nullptr) << dlerror();
   1285 
   1286   android_namespace_t* ns_not_isolated =
   1287           android_create_namespace("private",
   1288                                    nullptr,
   1289                                    (get_testlib_root() + "/private_namespace_libs").c_str(),
   1290                                    ANDROID_NAMESPACE_TYPE_REGULAR,
   1291                                    nullptr,
   1292                                    nullptr);
   1293   ASSERT_TRUE(ns_not_isolated != nullptr) << dlerror();
   1294   ASSERT_TRUE(android_link_namespaces(ns_not_isolated, nullptr, shared_libs.c_str())) << dlerror();
   1295 
   1296   android_namespace_t* ns_isolated_shared =
   1297           android_create_namespace("private_isolated_shared",
   1298                                    nullptr,
   1299                                    (get_testlib_root() + "/private_namespace_libs").c_str(),
   1300                                    ANDROID_NAMESPACE_TYPE_ISOLATED | ANDROID_NAMESPACE_TYPE_SHARED,
   1301                                    nullptr,
   1302                                    nullptr);
   1303   ASSERT_TRUE(ns_isolated_shared != nullptr) << dlerror();
   1304   ASSERT_TRUE(android_link_namespaces(ns_isolated_shared, nullptr, shared_libs.c_str())) << dlerror();
   1305 
   1306   ASSERT_TRUE(dlopen(root_lib, RTLD_NOW) == nullptr);
   1307   ASSERT_STREQ("dlopen failed: library \"libnstest_root_not_isolated.so\" not found", dlerror());
   1308 
   1309   std::string lib_private_external_path =
   1310       get_testlib_root() + "/private_namespace_libs_external/libnstest_private_external.so";
   1311 
   1312   // Load lib_private_external_path to default namespace
   1313   // (it should remain invisible for the isolated namespaces after this)
   1314   void* handle = dlopen(lib_private_external_path.c_str(), RTLD_NOW);
   1315   ASSERT_TRUE(handle != nullptr) << dlerror();
   1316 
   1317   android_dlextinfo extinfo;
   1318   extinfo.flags = ANDROID_DLEXT_USE_NAMESPACE;
   1319   extinfo.library_namespace = ns_not_isolated;
   1320 
   1321   void* handle1 = android_dlopen_ext(root_lib, RTLD_NOW, &extinfo);
   1322   ASSERT_TRUE(handle1 != nullptr) << dlerror();
   1323 
   1324   extinfo.library_namespace = ns_isolated_shared;
   1325 
   1326   void* handle2 = android_dlopen_ext(root_lib, RTLD_NOW, &extinfo);
   1327   ASSERT_TRUE(handle2 == nullptr);
   1328   ASSERT_STREQ("dlopen failed: library \"libnstest_private_external.so\" not found", dlerror());
   1329 
   1330   // Check dlopen by absolute path
   1331   handle2 = android_dlopen_ext(lib_private_external_path.c_str(), RTLD_NOW, &extinfo);
   1332   ASSERT_TRUE(handle2 == nullptr);
   1333   ASSERT_EQ("dlopen failed: library \"" + lib_private_external_path + "\" needed"
   1334             " or dlopened by \"" + get_executable_path() + "\" is not accessible"
   1335             " for the namespace \"private_isolated_shared\"", dlerror());
   1336 
   1337   // load libnstest_root.so to shared namespace in order to check that everything is different
   1338   // except shared libnstest_dlopened.so
   1339 
   1340   handle2 = android_dlopen_ext(root_lib_isolated, RTLD_NOW, &extinfo);
   1341 
   1342   typedef const char* (*fn_t)();
   1343   fn_t ns_get_local_string = reinterpret_cast<fn_t>(dlsym(handle1, "ns_get_local_string"));
   1344   ASSERT_TRUE(ns_get_local_string != nullptr) << dlerror();
   1345   fn_t ns_get_local_string_shared = reinterpret_cast<fn_t>(dlsym(handle2, "ns_get_local_string"));
   1346   ASSERT_TRUE(ns_get_local_string_shared != nullptr) << dlerror();
   1347 
   1348   ASSERT_STREQ("This string is local to root library", ns_get_local_string());
   1349   ASSERT_STREQ("This string is local to root library", ns_get_local_string_shared());
   1350   ASSERT_TRUE(ns_get_local_string() != ns_get_local_string_shared());
   1351 
   1352   fn_t ns_get_private_extern_string =
   1353           reinterpret_cast<fn_t>(dlsym(handle1, "ns_get_private_extern_string"));
   1354   ASSERT_TRUE(ns_get_private_extern_string != nullptr) << dlerror();
   1355   fn_t ns_get_private_extern_string_shared =
   1356           reinterpret_cast<fn_t>(dlsym(handle2, "ns_get_private_extern_string"));
   1357   ASSERT_TRUE(ns_get_private_extern_string_shared() != nullptr) << dlerror();
   1358 
   1359   ASSERT_STREQ("This string is from private namespace", ns_get_private_extern_string());
   1360   ASSERT_STREQ("This string is from private namespace", ns_get_private_extern_string_shared());
   1361   ASSERT_TRUE(ns_get_private_extern_string() != ns_get_private_extern_string_shared());
   1362 
   1363   fn_t ns_get_public_extern_string =
   1364           reinterpret_cast<fn_t>(dlsym(handle1, "ns_get_public_extern_string"));
   1365   ASSERT_TRUE(ns_get_public_extern_string != nullptr) << dlerror();
   1366   fn_t ns_get_public_extern_string_shared =
   1367           reinterpret_cast<fn_t>(dlsym(handle2, "ns_get_public_extern_string"));
   1368   ASSERT_TRUE(ns_get_public_extern_string_shared != nullptr) << dlerror();
   1369 
   1370   ASSERT_STREQ("This string is from public namespace", ns_get_public_extern_string());
   1371   ASSERT_STREQ("This string is from public namespace", ns_get_public_extern_string_shared());
   1372   ASSERT_TRUE(ns_get_public_extern_string() == ns_get_public_extern_string_shared());
   1373 
   1374   fn_t ns_get_dlopened_string = reinterpret_cast<fn_t>(dlsym(handle1, "ns_get_dlopened_string"));
   1375   ASSERT_TRUE(ns_get_dlopened_string != nullptr) << dlerror();
   1376   fn_t ns_get_dlopened_string_shared = reinterpret_cast<fn_t>(dlsym(handle2, "ns_get_dlopened_string"));
   1377   ASSERT_TRUE(ns_get_dlopened_string_shared != nullptr) << dlerror();
   1378   const char** ns_dlopened_string = static_cast<const char**>(dlsym(handle_dlopened, "g_private_dlopened_string"));
   1379   ASSERT_TRUE(ns_dlopened_string != nullptr) << dlerror();
   1380 
   1381   ASSERT_STREQ("This string is from private namespace (dlopened library)", ns_get_dlopened_string());
   1382   ASSERT_STREQ("This string is from private namespace (dlopened library)", *ns_dlopened_string);
   1383   ASSERT_STREQ("This string is from private namespace (dlopened library)", ns_get_dlopened_string_shared());
   1384   ASSERT_TRUE(ns_get_dlopened_string() != ns_get_dlopened_string_shared());
   1385   ASSERT_TRUE(*ns_dlopened_string == ns_get_dlopened_string_shared());
   1386 
   1387   dlclose(handle1);
   1388   dlclose(handle2);
   1389 }
   1390 
   1391 TEST(dlext, ns_shared_links_and_paths) {
   1392   // Create parent namespace (isolated, not shared)
   1393   android_namespace_t* ns_isolated =
   1394           android_create_namespace("private_isolated",
   1395                                    nullptr,
   1396                                    (get_testlib_root() + "/private_namespace_libs").c_str(),
   1397                                    ANDROID_NAMESPACE_TYPE_ISOLATED,
   1398                                    (get_testlib_root() + "/public_namespace_libs").c_str(),
   1399                                    nullptr);
   1400   ASSERT_TRUE(ns_isolated != nullptr) << dlerror();
   1401   ASSERT_TRUE(android_link_namespaces(ns_isolated, nullptr, g_core_shared_libs.c_str())) << dlerror();
   1402 
   1403   // Create shared namespace with ns_isolated parent
   1404   android_namespace_t* ns_shared =
   1405           android_create_namespace("private_shared",
   1406                                    nullptr,
   1407                                    nullptr,
   1408                                    ANDROID_NAMESPACE_TYPE_SHARED | ANDROID_NAMESPACE_TYPE_ISOLATED,
   1409                                    nullptr,
   1410                                    ns_isolated);
   1411   ASSERT_TRUE(ns_shared != nullptr) << dlerror();
   1412 
   1413   // 1. Load a library in ns_shared to check that it has inherited
   1414   // search path and the link to the default namespace.
   1415   android_dlextinfo extinfo;
   1416   extinfo.flags = ANDROID_DLEXT_USE_NAMESPACE;
   1417   extinfo.library_namespace = ns_shared;
   1418 
   1419   {
   1420     void* handle = android_dlopen_ext("libnstest_private.so", RTLD_NOW, &extinfo);
   1421     ASSERT_TRUE(handle != nullptr) << dlerror();
   1422     const char** ns_private_extern_string = static_cast<const char**>(dlsym(handle, "g_private_extern_string"));
   1423     ASSERT_TRUE(ns_private_extern_string != nullptr) << dlerror();
   1424     ASSERT_STREQ("This string is from private namespace", *ns_private_extern_string);
   1425 
   1426     dlclose(handle);
   1427   }
   1428   // 2. Load another test library by absolute path to check that
   1429   // it has inherited permitted_when_isolated_path
   1430   {
   1431     void* handle = android_dlopen_ext(
   1432             (get_testlib_root() + "/public_namespace_libs/libnstest_public.so").c_str(),
   1433             RTLD_NOW,
   1434             &extinfo);
   1435 
   1436     ASSERT_TRUE(handle != nullptr) << dlerror();
   1437     const char** ns_public_extern_string = static_cast<const char**>(dlsym(handle, "g_public_extern_string"));
   1438     ASSERT_TRUE(ns_public_extern_string != nullptr) << dlerror();
   1439     ASSERT_STREQ("This string is from public namespace", *ns_public_extern_string);
   1440 
   1441     dlclose(handle);
   1442   }
   1443 
   1444   // 3. Check that it is still isolated.
   1445   {
   1446     void* handle = android_dlopen_ext(
   1447             (get_testlib_root() + "/libtest_empty.so").c_str(),
   1448             RTLD_NOW,
   1449             &extinfo);
   1450 
   1451     ASSERT_TRUE(handle == nullptr);
   1452   }
   1453 }
   1454 
   1455 TEST(dlext, ns_shared_dlclose) {
   1456   android_set_application_target_sdk_version(42U); // something > 23
   1457 
   1458   ASSERT_TRUE(android_init_anonymous_namespace(g_core_shared_libs.c_str(), nullptr)) << dlerror();
   1459 
   1460   // preload this library to the default namespace to check if it
   1461   // is shared later on.
   1462   void* handle_dlopened =
   1463           dlopen((get_testlib_root() + "/private_namespace_libs/libnstest_dlopened.so").c_str(), RTLD_NOW);
   1464   ASSERT_TRUE(handle_dlopened != nullptr) << dlerror();
   1465 
   1466   android_namespace_t* ns_isolated_shared =
   1467           android_create_namespace("private_isolated_shared",
   1468                                    nullptr,
   1469                                    (get_testlib_root() + "/private_namespace_libs").c_str(),
   1470                                    ANDROID_NAMESPACE_TYPE_ISOLATED | ANDROID_NAMESPACE_TYPE_SHARED,
   1471                                    nullptr,
   1472                                    nullptr);
   1473   ASSERT_TRUE(ns_isolated_shared != nullptr) << dlerror();
   1474   ASSERT_TRUE(android_link_namespaces(ns_isolated_shared, nullptr, g_core_shared_libs.c_str())) << dlerror();
   1475 
   1476   // Check if "libnstest_dlopened.so" is loaded (and the same)
   1477   android_dlextinfo extinfo;
   1478   extinfo.flags = ANDROID_DLEXT_USE_NAMESPACE;
   1479   extinfo.library_namespace = ns_isolated_shared;
   1480 
   1481   void* handle = android_dlopen_ext("libnstest_dlopened.so", RTLD_NOW | RTLD_NOLOAD, &extinfo);
   1482   ASSERT_TRUE(handle != nullptr) << dlerror();
   1483   ASSERT_TRUE(handle == handle_dlopened);
   1484   dlclose(handle);
   1485   dlclose(handle_dlopened);
   1486 
   1487   // And now check that the library cannot be found by soname (and is no longer loaded)
   1488   handle = android_dlopen_ext("libnstest_dlopened.so", RTLD_NOW | RTLD_NOLOAD, &extinfo);
   1489   ASSERT_TRUE(handle == nullptr)
   1490       << "Error: libnstest_dlopened.so is still accessible in shared namespace";
   1491 
   1492   handle = android_dlopen_ext((get_testlib_root() + "/private_namespace_libs/libnstest_dlopened.so").c_str(),
   1493                               RTLD_NOW | RTLD_NOLOAD, &extinfo);
   1494   ASSERT_TRUE(handle == nullptr)
   1495       << "Error: libnstest_dlopened.so is still accessible in shared namespace";
   1496 
   1497   handle = dlopen("libnstest_dlopened.so", RTLD_NOW | RTLD_NOLOAD);
   1498   ASSERT_TRUE(handle == nullptr)
   1499       << "Error: libnstest_dlopened.so is still accessible in default namespace";
   1500 
   1501   handle = dlopen((get_testlib_root() + "/private_namespace_libs/libnstest_dlopened.so").c_str(),
   1502                   RTLD_NOW | RTLD_NOLOAD);
   1503   ASSERT_TRUE(handle == nullptr)
   1504       << "Error: libnstest_dlopened.so is still accessible in default namespace";
   1505 
   1506   // Now lets see if the soinfo area gets reused in the wrong way:
   1507   // load a library to default namespace.
   1508   const std::string lib_public_path = get_testlib_root() + "/public_namespace_libs/" + g_public_lib;
   1509   void* handle_public = dlopen(lib_public_path.c_str(), RTLD_NOW);
   1510   ASSERT_TRUE(handle_public != nullptr) << dlerror();
   1511 
   1512   // try to find it in shared namespace
   1513   handle = android_dlopen_ext(g_public_lib, RTLD_NOW | RTLD_NOLOAD, &extinfo);
   1514   ASSERT_TRUE(handle == nullptr)
   1515       << "Error: " << g_public_lib << " is accessible in shared namespace";
   1516 }
   1517 
   1518 TEST(dlext, ns_isolated_rtld_global) {
   1519   static const char* root_lib = "libnstest_root.so";
   1520   ASSERT_TRUE(android_init_anonymous_namespace(g_core_shared_libs.c_str(), nullptr));
   1521 
   1522   const std::string lib_public_path = get_testlib_root() + "/public_namespace_libs";
   1523 
   1524   android_namespace_t* ns1 =
   1525           android_create_namespace("isolated1",
   1526                                    nullptr,
   1527                                    (get_testlib_root() + "/private_namespace_libs").c_str(),
   1528                                    ANDROID_NAMESPACE_TYPE_ISOLATED,
   1529                                    lib_public_path.c_str(),
   1530                                    nullptr);
   1531   ASSERT_TRUE(ns1 != nullptr) << dlerror();
   1532   ASSERT_TRUE(android_link_namespaces(ns1, nullptr, g_core_shared_libs.c_str())) << dlerror();
   1533 
   1534   android_namespace_t* ns2 =
   1535           android_create_namespace("isolated2",
   1536                                    nullptr,
   1537                                    (get_testlib_root() + "/private_namespace_libs").c_str(),
   1538                                    ANDROID_NAMESPACE_TYPE_ISOLATED,
   1539                                    lib_public_path.c_str(),
   1540                                    nullptr);
   1541   ASSERT_TRUE(ns2 != nullptr) << dlerror();
   1542   ASSERT_TRUE(android_link_namespaces(ns2, nullptr, g_core_shared_libs.c_str())) << dlerror();
   1543 
   1544   android_dlextinfo extinfo;
   1545   extinfo.flags = ANDROID_DLEXT_USE_NAMESPACE;
   1546   extinfo.library_namespace = ns1;
   1547 
   1548   void* handle_global = android_dlopen_ext((lib_public_path + "/" + g_public_lib).c_str(),
   1549                                            RTLD_GLOBAL,
   1550                                            &extinfo);
   1551 
   1552   ASSERT_TRUE(handle_global != nullptr) << dlerror();
   1553 
   1554   android_namespace_t* ns1_child =
   1555           android_create_namespace("isolated1_child",
   1556                                    nullptr,
   1557                                    (get_testlib_root() + "/private_namespace_libs").c_str(),
   1558                                    ANDROID_NAMESPACE_TYPE_ISOLATED,
   1559                                    nullptr,
   1560                                    ns1);
   1561 
   1562   ASSERT_TRUE(ns1_child != nullptr) << dlerror();
   1563   ASSERT_TRUE(android_link_namespaces(ns1_child, nullptr, g_core_shared_libs.c_str())) << dlerror();
   1564 
   1565   // Now - only ns1 and ns1 child should be able to dlopen root_lib
   1566   // attempt to use ns2 should result in dlerror()
   1567 
   1568   // Check ns1_child first.
   1569   extinfo.flags = ANDROID_DLEXT_USE_NAMESPACE;
   1570   extinfo.library_namespace = ns1_child;
   1571 
   1572   void* handle1 = android_dlopen_ext(root_lib, RTLD_NOW, &extinfo);
   1573   ASSERT_TRUE(handle1 != nullptr) << dlerror();
   1574 
   1575   // now ns1
   1576   extinfo.flags = ANDROID_DLEXT_USE_NAMESPACE;
   1577   extinfo.library_namespace = ns1;
   1578 
   1579   handle1 = android_dlopen_ext(root_lib, RTLD_NOW, &extinfo);
   1580   ASSERT_TRUE(handle1 != nullptr) << dlerror();
   1581 
   1582   // and ns2 should fail
   1583   extinfo.flags = ANDROID_DLEXT_USE_NAMESPACE;
   1584   extinfo.library_namespace = ns2;
   1585 
   1586   handle1 = android_dlopen_ext(root_lib, RTLD_NOW, &extinfo);
   1587   ASSERT_TRUE(handle1 == nullptr);
   1588   ASSERT_STREQ("dlopen failed: library \"libnstest_public.so\" not found", dlerror());
   1589 }
   1590 
   1591 TEST(dlext, ns_anonymous) {
   1592   static const char* root_lib = "libnstest_root.so";
   1593   std::string shared_libs = g_core_shared_libs + ":" + g_public_lib;
   1594 
   1595   const std::string lib_public_path = get_testlib_root() + "/public_namespace_libs/" + g_public_lib;
   1596   void* handle_public = dlopen(lib_public_path.c_str(), RTLD_NOW);
   1597 
   1598   ASSERT_TRUE(handle_public != nullptr) << dlerror();
   1599 
   1600   ASSERT_TRUE(
   1601           android_init_anonymous_namespace(shared_libs.c_str(),
   1602                                            (get_testlib_root() + "/private_namespace_libs").c_str())
   1603       ) << dlerror();
   1604 
   1605   android_namespace_t* ns =
   1606           android_create_namespace("private",
   1607                                    nullptr,
   1608                                    (get_testlib_root() + "/private_namespace_libs").c_str(),
   1609                                    ANDROID_NAMESPACE_TYPE_REGULAR,
   1610                                    nullptr,
   1611                                    nullptr);
   1612 
   1613   ASSERT_TRUE(ns != nullptr) << dlerror();
   1614   ASSERT_TRUE(android_link_namespaces(ns, nullptr, shared_libs.c_str())) << dlerror();
   1615 
   1616   std::string private_library_absolute_path = get_testlib_root() + "/private_namespace_libs/" + root_lib;
   1617 
   1618   android_dlextinfo extinfo;
   1619   extinfo.flags = ANDROID_DLEXT_USE_NAMESPACE;
   1620   extinfo.library_namespace = ns;
   1621 
   1622   // we are going to copy this library to anonymous mmap and call the copy of ns_get_dlopened_string
   1623   void* handle = android_dlopen_ext(private_library_absolute_path.c_str(), RTLD_NOW, &extinfo);
   1624   ASSERT_TRUE(handle != nullptr) << dlerror();
   1625 
   1626   uintptr_t ns_get_dlopened_string_addr =
   1627       reinterpret_cast<uintptr_t>(dlsym(handle, "ns_get_dlopened_string"));
   1628   ASSERT_TRUE(ns_get_dlopened_string_addr != 0) << dlerror();
   1629   typedef const char* (*fn_t)();
   1630   fn_t ns_get_dlopened_string_private = reinterpret_cast<fn_t>(ns_get_dlopened_string_addr);
   1631 
   1632   std::vector<map_record> maps;
   1633   Maps::parse_maps(&maps);
   1634 
   1635   uintptr_t addr_start = 0;
   1636   uintptr_t addr_end = 0;
   1637   std::vector<map_record> maps_to_copy;
   1638 
   1639   for (const auto& rec : maps) {
   1640     if (rec.pathname == private_library_absolute_path) {
   1641       if (addr_start == 0) {
   1642         addr_start = rec.addr_start;
   1643       }
   1644       addr_end = rec.addr_end;
   1645 
   1646       maps_to_copy.push_back(rec);
   1647     }
   1648   }
   1649 
   1650   // some sanity checks..
   1651   ASSERT_TRUE(addr_start > 0);
   1652   ASSERT_TRUE(addr_end > 0);
   1653   ASSERT_EQ(3U, maps_to_copy.size());
   1654   ASSERT_TRUE(ns_get_dlopened_string_addr > addr_start);
   1655   ASSERT_TRUE(ns_get_dlopened_string_addr < addr_end);
   1656 
   1657   // copy
   1658   uintptr_t reserved_addr = reinterpret_cast<uintptr_t>(mmap(nullptr, addr_end - addr_start,
   1659                                                              PROT_NONE, MAP_ANON | MAP_PRIVATE,
   1660                                                              -1, 0));
   1661   ASSERT_TRUE(reinterpret_cast<void*>(reserved_addr) != MAP_FAILED);
   1662 
   1663   for (const auto& rec : maps_to_copy) {
   1664     uintptr_t offset = rec.addr_start - addr_start;
   1665     size_t size = rec.addr_end - rec.addr_start;
   1666     void* addr = reinterpret_cast<void*>(reserved_addr + offset);
   1667     void* map = mmap(addr, size, PROT_READ | PROT_WRITE,
   1668                      MAP_ANON | MAP_PRIVATE | MAP_FIXED, -1, 0);
   1669     ASSERT_TRUE(map != MAP_FAILED);
   1670     memcpy(map, reinterpret_cast<void*>(rec.addr_start), size);
   1671     mprotect(map, size, rec.perms);
   1672   }
   1673 
   1674   // call the function copy
   1675   uintptr_t ns_get_dlopened_string_offset  = ns_get_dlopened_string_addr - addr_start;
   1676   fn_t ns_get_dlopened_string_anon = reinterpret_cast<fn_t>(reserved_addr + ns_get_dlopened_string_offset);
   1677   ASSERT_STREQ("This string is from private namespace (dlopened library)",
   1678                ns_get_dlopened_string_anon());
   1679 
   1680   // They should belong to different namespaces (private and anonymous)
   1681   ASSERT_STREQ("This string is from private namespace (dlopened library)",
   1682                ns_get_dlopened_string_private());
   1683 
   1684   ASSERT_TRUE(ns_get_dlopened_string_anon() != ns_get_dlopened_string_private());
   1685 }
   1686 
   1687 TEST(dlext, dlopen_handle_value_platform) {
   1688   void* handle = dlopen("libtest_dlsym_from_this.so", RTLD_NOW | RTLD_LOCAL);
   1689   ASSERT_TRUE((reinterpret_cast<uintptr_t>(handle) & 1) != 0)
   1690           << "dlopen should return odd value for the handle";
   1691   dlclose(handle);
   1692 }
   1693 
   1694 TEST(dlext, dlopen_handle_value_app_compat) {
   1695   android_set_application_target_sdk_version(__ANDROID_API_M__);
   1696   void* handle = dlopen("libtest_dlsym_from_this.so", RTLD_NOW | RTLD_LOCAL);
   1697   ASSERT_TRUE(reinterpret_cast<uintptr_t>(handle) % sizeof(uintptr_t) == 0)
   1698           << "dlopen should return valid pointer";
   1699   dlclose(handle);
   1700 }
   1701