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_writer_quick.h"
  25 #include "oat.h"
  26 #include "utils.h"
  27
  28 namespace art {
  29
  30 class ElfWriterTest : public CommonCompilerTest {
  31  protected:
  32   virtual void SetUp() {
  33     ReserveImageSpace();
  34     CommonCompilerTest::SetUp();
  35   }
  36 };
  37
  38 #define EXPECT_ELF_FILE_ADDRESS(ef, expected_value, symbol_name, build_map) \
  39   do { \
  40     void* addr = reinterpret_cast<void*>(ef->FindSymbolAddress(SHT_DYNSYM, \
  41                                                                symbol_name, \
  42                                                                build_map)); \
  43     EXPECT_NE(nullptr, addr); \
  44     EXPECT_LT(static_cast<uintptr_t>(ART_BASE_ADDRESS), reinterpret_cast<uintptr_t>(addr)); \
  45     if (expected_value == nullptr) { \
  46       expected_value = addr; \
  47     }                        \
  48     EXPECT_EQ(expected_value, addr); \
  49     EXPECT_EQ(expected_value, ef->FindDynamicSymbolAddress(symbol_name)); \
  50   } while (false)
  51
  52 TEST_F(ElfWriterTest, dlsym) {
  53   std::string elf_location = GetCoreOatLocation();
  54   std::string elf_filename = GetSystemImageFilename(elf_location.c_str(), kRuntimeISA);
  55   LOG(INFO) << "elf_filename=" << elf_filename;
  56
  57   UnreserveImageSpace();
  58   void* dl_oatdata = nullptr;
  59   void* dl_oatexec = nullptr;
  60   void* dl_oatlastword = nullptr;
  61
  62   std::unique_ptr<File> file(OS::OpenFileForReading(elf_filename.c_str()));
  63   ASSERT_TRUE(file.get() != nullptr);
  64   {
  65     std::string error_msg;
  66     std::unique_ptr<ElfFile> ef(ElfFile::Open(file.get(), false, false, &error_msg));
  67     CHECK(ef.get() != nullptr) << error_msg;
  68     EXPECT_ELF_FILE_ADDRESS(ef, dl_oatdata, "oatdata", false);
  69     EXPECT_ELF_FILE_ADDRESS(ef, dl_oatexec, "oatexec", false);
  70     EXPECT_ELF_FILE_ADDRESS(ef, dl_oatlastword, "oatlastword", false);
  71   }
  72   {
  73     std::string error_msg;
  74     std::unique_ptr<ElfFile> ef(ElfFile::Open(file.get(), false, false, &error_msg));
  75     CHECK(ef.get() != nullptr) << error_msg;
  76     EXPECT_ELF_FILE_ADDRESS(ef, dl_oatdata, "oatdata", true);
  77     EXPECT_ELF_FILE_ADDRESS(ef, dl_oatexec, "oatexec", true);
  78     EXPECT_ELF_FILE_ADDRESS(ef, dl_oatlastword, "oatlastword", true);
  79   }
  80   {
  81     std::string error_msg;
  82     std::unique_ptr<ElfFile> ef(ElfFile::Open(file.get(), false, true, &error_msg));
  83     CHECK(ef.get() != nullptr) << error_msg;
  84     CHECK(ef->Load(false, &error_msg)) << error_msg;
  85     EXPECT_EQ(dl_oatdata, ef->FindDynamicSymbolAddress("oatdata"));
  86     EXPECT_EQ(dl_oatexec, ef->FindDynamicSymbolAddress("oatexec"));
  87     EXPECT_EQ(dl_oatlastword, ef->FindDynamicSymbolAddress("oatlastword"));
  88   }
  89 }
  90
  91 TEST_F(ElfWriterTest, EncodeDecodeOatPatches) {
  92   const std::vector<std::vector<uintptr_t>> test_data {
  93       { 0, 4, 8, 15, 128, 200 },
  94       { 8, 8 + 127 },
  95       { 8, 8 + 128 },
  96       { },
  97   };
  98   for (const auto& patch_locations : test_data) {
  99     constexpr int32_t delta = 0x11235813;
 100
 101     // Encode patch locations.
 102     std::vector<uint8_t> oat_patches;
 103     ElfWriterQuick32::EncodeOatPatches(patch_locations, &oat_patches);
 104
 105     // Create buffer to be patched.
 106     std::vector<uint8_t> initial_data(256);
 107     for (size_t i = 0; i < initial_data.size(); i++) {
 108       initial_data[i] = i;
 109     }
 110
 111     // Patch manually.
 112     std::vector<uint8_t> expected = initial_data;
 113     for (uintptr_t location : patch_locations) {
 114       typedef __attribute__((__aligned__(1))) uint32_t UnalignedAddress;
 115       *reinterpret_cast<UnalignedAddress*>(expected.data() + location) += delta;
 116     }
 117
 118     // Decode and apply patch locations.
 119     std::vector<uint8_t> actual = initial_data;
 120     ElfFileImpl32::ApplyOatPatches(
 121         oat_patches.data(), oat_patches.data() + oat_patches.size(), delta,
 122         actual.data(), actual.data() + actual.size());
 123
 124     EXPECT_EQ(expected, actual);
 125   }
 126 }
 127
 128 }  // namespace art