compiler/elf_writer_test.cc

   1 /*
   2  * Copyright (C) 2011 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 "elf_file.h"
  18
  19 #include "base/stringprintf.h"
  20 #include "base/unix_file/fd_file.h"
  21 #include "common_compiler_test.h"
  22 #include "elf_file.h"
  23 #include "elf_file_impl.h"
  24 #include "elf_builder.h"
  25 #include "elf_writer_quick.h"
  26 #include "oat.h"
  27 #include "utils.h"
  28
  29 namespace art {
  30
  31 class ElfWriterTest : public CommonCompilerTest {
  32  protected:
  33   virtual void SetUp() {
  34     ReserveImageSpace();
  35     CommonCompilerTest::SetUp();
  36   }
  37 };
  38
  39 #define EXPECT_ELF_FILE_ADDRESS(ef, expected_value, symbol_name, build_map) \
  40   do { \
  41     void* addr = reinterpret_cast<void*>(ef->FindSymbolAddress(SHT_DYNSYM, \
  42                                                                symbol_name, \
  43                                                                build_map)); \
  44     EXPECT_NE(nullptr, addr); \
  45     EXPECT_LT(static_cast<uintptr_t>(ART_BASE_ADDRESS), reinterpret_cast<uintptr_t>(addr)); \
  46     if (expected_value == nullptr) { \
  47       expected_value = addr; \
  48     }                        \
  49     EXPECT_EQ(expected_value, addr); \
  50     EXPECT_EQ(expected_value, ef->FindDynamicSymbolAddress(symbol_name)); \
  51   } while (false)
  52
  53 TEST_F(ElfWriterTest, dlsym) {
  54   std::string elf_location = GetCoreOatLocation();
  55   std::string elf_filename = GetSystemImageFilename(elf_location.c_str(), kRuntimeISA);
  56   LOG(INFO) << "elf_filename=" << elf_filename;
  57
  58   UnreserveImageSpace();
  59   void* dl_oatdata = nullptr;
  60   void* dl_oatexec = nullptr;
  61   void* dl_oatlastword = nullptr;
  62
  63   std::unique_ptr<File> file(OS::OpenFileForReading(elf_filename.c_str()));
  64   ASSERT_TRUE(file.get() != nullptr);
  65   {
  66     std::string error_msg;
  67     std::unique_ptr<ElfFile> ef(ElfFile::Open(file.get(),
  68                                               false,
  69                                               false,
  70                                               /*low_4gb*/false,
  71                                               &error_msg));
  72     CHECK(ef.get() != nullptr) << error_msg;
  73     EXPECT_ELF_FILE_ADDRESS(ef, dl_oatdata, "oatdata", false);
  74     EXPECT_ELF_FILE_ADDRESS(ef, dl_oatexec, "oatexec", false);
  75     EXPECT_ELF_FILE_ADDRESS(ef, dl_oatlastword, "oatlastword", false);
  76   }
  77   {
  78     std::string error_msg;
  79     std::unique_ptr<ElfFile> ef(ElfFile::Open(file.get(),
  80                                               false,
  81                                               false,
  82                                               /*low_4gb*/false,
  83                                               &error_msg));
  84     CHECK(ef.get() != nullptr) << error_msg;
  85     EXPECT_ELF_FILE_ADDRESS(ef, dl_oatdata, "oatdata", true);
  86     EXPECT_ELF_FILE_ADDRESS(ef, dl_oatexec, "oatexec", true);
  87     EXPECT_ELF_FILE_ADDRESS(ef, dl_oatlastword, "oatlastword", true);
  88   }
  89   {
  90     std::string error_msg;
  91     std::unique_ptr<ElfFile> ef(ElfFile::Open(file.get(),
  92                                               false,
  93                                               true,
  94                                               /*low_4gb*/false,
  95                                               &error_msg));
  96     CHECK(ef.get() != nullptr) << error_msg;
  97     CHECK(ef->Load(false, /*low_4gb*/false, &error_msg)) << error_msg;
  98     EXPECT_EQ(dl_oatdata, ef->FindDynamicSymbolAddress("oatdata"));
  99     EXPECT_EQ(dl_oatexec, ef->FindDynamicSymbolAddress("oatexec"));
 100     EXPECT_EQ(dl_oatlastword, ef->FindDynamicSymbolAddress("oatlastword"));
 101   }
 102 }
 103
 104 TEST_F(ElfWriterTest, EncodeDecodeOatPatches) {
 105   const std::vector<std::vector<uintptr_t>> test_data {
 106       { 0, 4, 8, 15, 128, 200 },
 107       { 8, 8 + 127 },
 108       { 8, 8 + 128 },
 109       { },
 110   };
 111   for (const auto& patch_locations : test_data) {
 112     constexpr int32_t delta = 0x11235813;
 113
 114     // Encode patch locations.
 115     std::vector<uint8_t> oat_patches;
 116     ElfBuilder<ElfTypes32>::EncodeOatPatches(ArrayRef<const uintptr_t>(patch_locations),
 117                                              &oat_patches);
 118
 119     // Create buffer to be patched.
 120     std::vector<uint8_t> initial_data(256);
 121     for (size_t i = 0; i < initial_data.size(); i++) {
 122       initial_data[i] = i;
 123     }
 124
 125     // Patch manually.
 126     std::vector<uint8_t> expected = initial_data;
 127     for (uintptr_t location : patch_locations) {
 128       typedef __attribute__((__aligned__(1))) uint32_t UnalignedAddress;
 129       *reinterpret_cast<UnalignedAddress*>(expected.data() + location) += delta;
 130     }
 131
 132     // Decode and apply patch locations.
 133     std::vector<uint8_t> actual = initial_data;
 134     ElfFileImpl32::ApplyOatPatches(
 135         oat_patches.data(), oat_patches.data() + oat_patches.size(), delta,
 136         actual.data(), actual.data() + actual.size());
 137
 138     EXPECT_EQ(expected, actual);
 139   }
 140 }
 141
 142 }  // namespace art