bolt/unittests/Core/BinaryContext.cpp

   1 //===- bolt/unittest/Core/BinaryContext.cpp -------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "bolt/Core/BinaryContext.h"
  10 #include "llvm/BinaryFormat/ELF.h"
  11 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
  12 #include "llvm/Support/TargetSelect.h"
  13 #include "gtest/gtest.h"
  14
  15 using namespace llvm;
  16 using namespace llvm::object;
  17 using namespace llvm::ELF;
  18 using namespace bolt;
  19
  20 namespace {
  21 struct BinaryContextTester : public testing::TestWithParam<Triple::ArchType> {
  22   void SetUp() override {
  23     initalizeLLVM();
  24     prepareElf();
  25     initializeBOLT();
  26   }
  27
  28 protected:
  29   void initalizeLLVM() {
  30     llvm::InitializeAllTargetInfos();
  31     llvm::InitializeAllTargetMCs();
  32     llvm::InitializeAllAsmParsers();
  33     llvm::InitializeAllDisassemblers();
  34     llvm::InitializeAllTargets();
  35     llvm::InitializeAllAsmPrinters();
  36   }
  37
  38   void prepareElf() {
  39     memcpy(ElfBuf, "\177ELF", 4);
  40     ELF64LE::Ehdr *EHdr = reinterpret_cast<typename ELF64LE::Ehdr *>(ElfBuf);
  41     EHdr->e_ident[llvm::ELF::EI_CLASS] = llvm::ELF::ELFCLASS64;
  42     EHdr->e_ident[llvm::ELF::EI_DATA] = llvm::ELF::ELFDATA2LSB;
  43     EHdr->e_machine = GetParam() == Triple::aarch64 ? EM_AARCH64 : EM_X86_64;
  44     MemoryBufferRef Source(StringRef(ElfBuf, sizeof(ElfBuf)), "ELF");
  45     ObjFile = cantFail(ObjectFile::createObjectFile(Source));
  46   }
  47
  48   void initializeBOLT() {
  49     Relocation::Arch = ObjFile->makeTriple().getArch();
  50     BC = cantFail(BinaryContext::createBinaryContext(
  51         ObjFile->makeTriple(), ObjFile->getFileName(), nullptr, true,
  52         DWARFContext::create(*ObjFile.get()), {llvm::outs(), llvm::errs()}));
  53     ASSERT_FALSE(!BC);
  54   }
  55
  56   char ElfBuf[sizeof(typename ELF64LE::Ehdr)] = {};
  57   std::unique_ptr<ObjectFile> ObjFile;
  58   std::unique_ptr<BinaryContext> BC;
  59 };
  60 } // namespace
  61
  62 #ifdef X86_AVAILABLE
  63
  64 INSTANTIATE_TEST_SUITE_P(X86, BinaryContextTester,
  65                          ::testing::Values(Triple::x86_64));
  66
  67 #endif
  68
  69 #ifdef AARCH64_AVAILABLE
  70
  71 INSTANTIATE_TEST_SUITE_P(AArch64, BinaryContextTester,
  72                          ::testing::Values(Triple::aarch64));
  73
  74 TEST_P(BinaryContextTester, FlushPendingRelocCALL26) {
  75   if (GetParam() != Triple::aarch64)
  76     GTEST_SKIP();
  77
  78   // This test checks that encodeValueAArch64 used by flushPendingRelocations
  79   // returns correctly encoded values for CALL26 relocation for both backward
  80   // and forward branches.
  81   //
  82   // The offsets layout is:
  83   // 4:  func1
  84   // 8:  bl func1
  85   // 12: bl func2
  86   // 16: func2
  87
  88   constexpr size_t DataSize = 20;
  89   uint8_t *Data = new uint8_t[DataSize];
  90   BinarySection &BS = BC->registerOrUpdateSection(
  91       ".text", ELF::SHT_PROGBITS, ELF::SHF_EXECINSTR | ELF::SHF_ALLOC, Data,
  92       DataSize, 4);
  93   MCSymbol *RelSymbol1 = BC->getOrCreateGlobalSymbol(4, "Func1");
  94   ASSERT_TRUE(RelSymbol1);
  95   BS.addRelocation(8, RelSymbol1, ELF::R_AARCH64_CALL26, 0, 0, true);
  96   MCSymbol *RelSymbol2 = BC->getOrCreateGlobalSymbol(16, "Func2");
  97   ASSERT_TRUE(RelSymbol2);
  98   BS.addRelocation(12, RelSymbol2, ELF::R_AARCH64_CALL26, 0, 0, true);
  99
 100   std::error_code EC;
 101   SmallVector<char> Vect(DataSize);
 102   raw_svector_ostream OS(Vect);
 103
 104   BS.flushPendingRelocations(OS, [&](const MCSymbol *S) {
 105     return S == RelSymbol1 ? 4 : S == RelSymbol2 ? 16 : 0;
 106   });
 107
 108   const uint8_t Func1Call[4] = {255, 255, 255, 151};
 109   const uint8_t Func2Call[4] = {1, 0, 0, 148};
 110
 111   EXPECT_FALSE(memcmp(Func1Call, &Vect[8], 4)) << "Wrong backward call value\n";
 112   EXPECT_FALSE(memcmp(Func2Call, &Vect[12], 4)) << "Wrong forward call value\n";
 113 }
 114
 115 TEST_P(BinaryContextTester, FlushPendingRelocJUMP26) {
 116   if (GetParam() != Triple::aarch64)
 117     GTEST_SKIP();
 118
 119   // This test checks that encodeValueAArch64 used by flushPendingRelocations
 120   // returns correctly encoded values for R_AARCH64_JUMP26 relocation for both
 121   // backward and forward branches.
 122   //
 123   // The offsets layout is:
 124   // 4:  func1
 125   // 8:  b func1
 126   // 12: b func2
 127   // 16: func2
 128
 129   const uint64_t Size = 20;
 130   char *Data = new char[Size];
 131   BinarySection &BS = BC->registerOrUpdateSection(
 132       ".text", ELF::SHT_PROGBITS, ELF::SHF_EXECINSTR | ELF::SHF_ALLOC,
 133       (uint8_t *)Data, Size, 4);
 134   MCSymbol *RelSymbol1 = BC->getOrCreateGlobalSymbol(4, "Func1");
 135   ASSERT_TRUE(RelSymbol1);
 136   BS.addRelocation(8, RelSymbol1, ELF::R_AARCH64_JUMP26, 0, 0, true);
 137   MCSymbol *RelSymbol2 = BC->getOrCreateGlobalSymbol(16, "Func2");
 138   ASSERT_TRUE(RelSymbol2);
 139   BS.addRelocation(12, RelSymbol2, ELF::R_AARCH64_JUMP26, 0, 0, true);
 140
 141   std::error_code EC;
 142   SmallVector<char> Vect(Size);
 143   raw_svector_ostream OS(Vect);
 144
 145   BS.flushPendingRelocations(OS, [&](const MCSymbol *S) {
 146     return S == RelSymbol1 ? 4 : S == RelSymbol2 ? 16 : 0;
 147   });
 148
 149   const uint8_t Func1Call[4] = {255, 255, 255, 23};
 150   const uint8_t Func2Call[4] = {1, 0, 0, 20};
 151
 152   EXPECT_FALSE(memcmp(Func1Call, &Vect[8], 4))
 153       << "Wrong backward branch value\n";
 154   EXPECT_FALSE(memcmp(Func2Call, &Vect[12], 4))
 155       << "Wrong forward branch value\n";
 156 }
 157
 158 #endif
 159
 160 TEST_P(BinaryContextTester, BaseAddress) {
 161   // Check that  base address calculation is correct for a binary with the
 162   // following segment layout:
 163   BC->SegmentMapInfo[0] =
 164       SegmentInfo{0, 0x10e8c2b4, 0, 0x10e8c2b4, 0x1000, true};
 165   BC->SegmentMapInfo[0x10e8d2b4] =
 166       SegmentInfo{0x10e8d2b4, 0x3952faec, 0x10e8c2b4, 0x3952faec, 0x1000, true};
 167   BC->SegmentMapInfo[0x4a3bddc0] =
 168       SegmentInfo{0x4a3bddc0, 0x148e828, 0x4a3bbdc0, 0x148e828, 0x1000, true};
 169   BC->SegmentMapInfo[0x4b84d5e8] =
 170       SegmentInfo{0x4b84d5e8, 0x294f830, 0x4b84a5e8, 0x3d3820, 0x1000, true};
 171
 172   std::optional<uint64_t> BaseAddress =
 173       BC->getBaseAddressForMapping(0x7f13f5556000, 0x10e8c000);
 174   ASSERT_TRUE(BaseAddress.has_value());
 175   ASSERT_EQ(*BaseAddress, 0x7f13e46c9000ULL);
 176
 177   BaseAddress = BC->getBaseAddressForMapping(0x7f13f5556000, 0x137a000);
 178   ASSERT_FALSE(BaseAddress.has_value());
 179 }
 180
 181 TEST_P(BinaryContextTester, BaseAddress2) {
 182   // Check that base address calculation is correct for a binary if the
 183   // alignment in ELF file are different from pagesize.
 184   // The segment layout is as follows:
 185   BC->SegmentMapInfo[0] = SegmentInfo{0, 0x2177c, 0, 0x2177c, 0x10000, true};
 186   BC->SegmentMapInfo[0x31860] =
 187       SegmentInfo{0x31860, 0x370, 0x21860, 0x370, 0x10000, true};
 188   BC->SegmentMapInfo[0x41c20] =
 189       SegmentInfo{0x41c20, 0x1f8, 0x21c20, 0x1f8, 0x10000, true};
 190   BC->SegmentMapInfo[0x54e18] =
 191       SegmentInfo{0x54e18, 0x51, 0x24e18, 0x51, 0x10000, true};
 192
 193   std::optional<uint64_t> BaseAddress =
 194       BC->getBaseAddressForMapping(0xaaaaea444000, 0x21000);
 195   ASSERT_TRUE(BaseAddress.has_value());
 196   ASSERT_EQ(*BaseAddress, 0xaaaaea413000ULL);
 197
 198   BaseAddress = BC->getBaseAddressForMapping(0xaaaaea444000, 0x11000);
 199   ASSERT_FALSE(BaseAddress.has_value());
 200 }
 201
 202 TEST_P(BinaryContextTester, BaseAddressSegmentsSmallerThanAlignment) {
 203   // Check that the correct segment is used to compute the base address
 204   // when multiple segments are close together in the ELF file (closer
 205   // than the required alignment in the process space).
 206   // See https://github.com/llvm/llvm-project/issues/109384
 207   BC->SegmentMapInfo[0] = SegmentInfo{0, 0x1d1c, 0, 0x1d1c, 0x10000, false};
 208   BC->SegmentMapInfo[0x11d40] =
 209       SegmentInfo{0x11d40, 0x11e0, 0x1d40, 0x11e0, 0x10000, true};
 210   BC->SegmentMapInfo[0x22f20] =
 211       SegmentInfo{0x22f20, 0x10e0, 0x2f20, 0x1f0, 0x10000, false};
 212   BC->SegmentMapInfo[0x33110] =
 213       SegmentInfo{0x33110, 0x89, 0x3110, 0x88, 0x10000, false};
 214
 215   std::optional<uint64_t> BaseAddress =
 216       BC->getBaseAddressForMapping(0xaaaaaaab1000, 0x1000);
 217   ASSERT_TRUE(BaseAddress.has_value());
 218   ASSERT_EQ(*BaseAddress, 0xaaaaaaaa0000ULL);
 219 }