diff lib/Object/ELF.cpp @ 148:63bd29f05246

merged
author Shinji KONO <kono@ie.u-ryukyu.ac.jp>
date Wed, 14 Aug 2019 19:46:37 +0900
parents c2174574ed3a
children
line wrap: on
line diff
--- a/lib/Object/ELF.cpp	Sun Dec 23 19:23:36 2018 +0900
+++ b/lib/Object/ELF.cpp	Wed Aug 14 19:46:37 2019 +0900
@@ -1,9 +1,8 @@
 //===- ELF.cpp - ELF object file implementation ---------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
@@ -125,13 +124,6 @@
       break;
     }
     break;
-  case ELF::EM_WEBASSEMBLY:
-    switch (Type) {
-#include "llvm/BinaryFormat/ELFRelocs/WebAssembly.def"
-    default:
-      break;
-    }
-    break;
   case ELF::EM_AMDGPU:
     switch (Type) {
 #include "llvm/BinaryFormat/ELFRelocs/AMDGPU.def"
@@ -146,6 +138,13 @@
       break;
     }
     break;
+  case ELF::EM_MSP430:
+    switch (Type) {
+#include "llvm/BinaryFormat/ELFRelocs/MSP430.def"
+    default:
+      break;
+    }
+    break;
   default:
     break;
   }
@@ -154,6 +153,50 @@
 
 #undef ELF_RELOC
 
+uint32_t llvm::object::getELFRelativeRelocationType(uint32_t Machine) {
+  switch (Machine) {
+  case ELF::EM_X86_64:
+    return ELF::R_X86_64_RELATIVE;
+  case ELF::EM_386:
+  case ELF::EM_IAMCU:
+    return ELF::R_386_RELATIVE;
+  case ELF::EM_MIPS:
+    break;
+  case ELF::EM_AARCH64:
+    return ELF::R_AARCH64_RELATIVE;
+  case ELF::EM_ARM:
+    return ELF::R_ARM_RELATIVE;
+  case ELF::EM_ARC_COMPACT:
+  case ELF::EM_ARC_COMPACT2:
+    return ELF::R_ARC_RELATIVE;
+  case ELF::EM_AVR:
+    break;
+  case ELF::EM_HEXAGON:
+    return ELF::R_HEX_RELATIVE;
+  case ELF::EM_LANAI:
+    break;
+  case ELF::EM_PPC:
+    break;
+  case ELF::EM_PPC64:
+    return ELF::R_PPC64_RELATIVE;
+  case ELF::EM_RISCV:
+    return ELF::R_RISCV_RELATIVE;
+  case ELF::EM_S390:
+    return ELF::R_390_RELATIVE;
+  case ELF::EM_SPARC:
+  case ELF::EM_SPARC32PLUS:
+  case ELF::EM_SPARCV9:
+    return ELF::R_SPARC_RELATIVE;
+  case ELF::EM_AMDGPU:
+    break;
+  case ELF::EM_BPF:
+    break;
+  default:
+    break;
+  }
+  return 0;
+}
+
 StringRef llvm::object::getELFSectionTypeName(uint32_t Machine, unsigned Type) {
   switch (Machine) {
   case ELF::EM_ARM:
@@ -176,8 +219,8 @@
     switch (Type) {
       STRINGIFY_ENUM_CASE(ELF, SHT_MIPS_REGINFO);
       STRINGIFY_ENUM_CASE(ELF, SHT_MIPS_OPTIONS);
+      STRINGIFY_ENUM_CASE(ELF, SHT_MIPS_DWARF);
       STRINGIFY_ENUM_CASE(ELF, SHT_MIPS_ABIFLAGS);
-      STRINGIFY_ENUM_CASE(ELF, SHT_MIPS_DWARF);
     }
     break;
   default:
@@ -202,10 +245,16 @@
     STRINGIFY_ENUM_CASE(ELF, SHT_PREINIT_ARRAY);
     STRINGIFY_ENUM_CASE(ELF, SHT_GROUP);
     STRINGIFY_ENUM_CASE(ELF, SHT_SYMTAB_SHNDX);
+    STRINGIFY_ENUM_CASE(ELF, SHT_RELR);
     STRINGIFY_ENUM_CASE(ELF, SHT_ANDROID_REL);
     STRINGIFY_ENUM_CASE(ELF, SHT_ANDROID_RELA);
+    STRINGIFY_ENUM_CASE(ELF, SHT_ANDROID_RELR);
     STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_ODRTAB);
     STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_LINKER_OPTIONS);
+    STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_CALL_GRAPH_PROFILE);
+    STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_ADDRSIG);
+    STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_DEPENDENT_LIBRARIES);
+    STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_SYMPART);
     STRINGIFY_ENUM_CASE(ELF, SHT_GNU_ATTRIBUTES);
     STRINGIFY_ENUM_CASE(ELF, SHT_GNU_HASH);
     STRINGIFY_ENUM_CASE(ELF, SHT_GNU_verdef);
@@ -218,6 +267,85 @@
 
 template <class ELFT>
 Expected<std::vector<typename ELFT::Rela>>
+ELFFile<ELFT>::decode_relrs(Elf_Relr_Range relrs) const {
+  // This function decodes the contents of an SHT_RELR packed relocation
+  // section.
+  //
+  // Proposal for adding SHT_RELR sections to generic-abi is here:
+  //   https://groups.google.com/forum/#!topic/generic-abi/bX460iggiKg
+  //
+  // The encoded sequence of Elf64_Relr entries in a SHT_RELR section looks
+  // like [ AAAAAAAA BBBBBBB1 BBBBBBB1 ... AAAAAAAA BBBBBB1 ... ]
+  //
+  // i.e. start with an address, followed by any number of bitmaps. The address
+  // entry encodes 1 relocation. The subsequent bitmap entries encode up to 63
+  // relocations each, at subsequent offsets following the last address entry.
+  //
+  // The bitmap entries must have 1 in the least significant bit. The assumption
+  // here is that an address cannot have 1 in lsb. Odd addresses are not
+  // supported.
+  //
+  // Excluding the least significant bit in the bitmap, each non-zero bit in
+  // the bitmap represents a relocation to be applied to a corresponding machine
+  // word that follows the base address word. The second least significant bit
+  // represents the machine word immediately following the initial address, and
+  // each bit that follows represents the next word, in linear order. As such,
+  // a single bitmap can encode up to 31 relocations in a 32-bit object, and
+  // 63 relocations in a 64-bit object.
+  //
+  // This encoding has a couple of interesting properties:
+  // 1. Looking at any entry, it is clear whether it's an address or a bitmap:
+  //    even means address, odd means bitmap.
+  // 2. Just a simple list of addresses is a valid encoding.
+
+  Elf_Rela Rela;
+  Rela.r_info = 0;
+  Rela.r_addend = 0;
+  Rela.setType(getRelativeRelocationType(), false);
+  std::vector<Elf_Rela> Relocs;
+
+  // Word type: uint32_t for Elf32, and uint64_t for Elf64.
+  typedef typename ELFT::uint Word;
+
+  // Word size in number of bytes.
+  const size_t WordSize = sizeof(Word);
+
+  // Number of bits used for the relocation offsets bitmap.
+  // These many relative relocations can be encoded in a single entry.
+  const size_t NBits = 8*WordSize - 1;
+
+  Word Base = 0;
+  for (const Elf_Relr &R : relrs) {
+    Word Entry = R;
+    if ((Entry&1) == 0) {
+      // Even entry: encodes the offset for next relocation.
+      Rela.r_offset = Entry;
+      Relocs.push_back(Rela);
+      // Set base offset for subsequent bitmap entries.
+      Base = Entry + WordSize;
+      continue;
+    }
+
+    // Odd entry: encodes bitmap for relocations starting at base.
+    Word Offset = Base;
+    while (Entry != 0) {
+      Entry >>= 1;
+      if ((Entry&1) != 0) {
+        Rela.r_offset = Offset;
+        Relocs.push_back(Rela);
+      }
+      Offset += WordSize;
+    }
+
+    // Advance base offset by NBits words.
+    Base += NBits * WordSize;
+  }
+
+  return Relocs;
+}
+
+template <class ELFT>
+Expected<std::vector<typename ELFT::Rela>>
 ELFFile<ELFT>::android_relas(const Elf_Shdr *Sec) const {
   // This function reads relocations in Android's packed relocation format,
   // which is based on SLEB128 and delta encoding.
@@ -273,20 +401,17 @@
     if (GroupedByAddend && GroupHasAddend)
       Addend += ReadSLEB();
 
+    if (!GroupHasAddend)
+      Addend = 0;
+
     for (uint64_t I = 0; I != NumRelocsInGroup; ++I) {
       Elf_Rela R;
       Offset += GroupedByOffsetDelta ? GroupOffsetDelta : ReadSLEB();
       R.r_offset = Offset;
       R.r_info = GroupedByInfo ? GroupRInfo : ReadSLEB();
-
-      if (GroupHasAddend) {
-        if (!GroupedByAddend)
-          Addend += ReadSLEB();
-        R.r_addend = Addend;
-      } else {
-        R.r_addend = 0;
-      }
-
+      if (GroupHasAddend && !GroupedByAddend)
+        Addend += ReadSLEB();
+      R.r_addend = Addend;
       Relocs.push_back(R);
 
       if (ErrStr)
@@ -300,6 +425,162 @@
   return Relocs;
 }
 
+template <class ELFT>
+std::string ELFFile<ELFT>::getDynamicTagAsString(unsigned Arch,
+                                                 uint64_t Type) const {
+#define DYNAMIC_STRINGIFY_ENUM(tag, value)                                     \
+  case value:                                                                  \
+    return #tag;
+
+#define DYNAMIC_TAG(n, v)
+  switch (Arch) {
+  case ELF::EM_AARCH64:
+    switch (Type) {
+#define AARCH64_DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value)
+#include "llvm/BinaryFormat/DynamicTags.def"
+#undef AARCH64_DYNAMIC_TAG
+    }
+    break;
+
+  case ELF::EM_HEXAGON:
+    switch (Type) {
+#define HEXAGON_DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value)
+#include "llvm/BinaryFormat/DynamicTags.def"
+#undef HEXAGON_DYNAMIC_TAG
+    }
+    break;
+
+  case ELF::EM_MIPS:
+    switch (Type) {
+#define MIPS_DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value)
+#include "llvm/BinaryFormat/DynamicTags.def"
+#undef MIPS_DYNAMIC_TAG
+    }
+    break;
+
+  case ELF::EM_PPC64:
+    switch (Type) {
+#define PPC64_DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value)
+#include "llvm/BinaryFormat/DynamicTags.def"
+#undef PPC64_DYNAMIC_TAG
+    }
+    break;
+  }
+#undef DYNAMIC_TAG
+  switch (Type) {
+// Now handle all dynamic tags except the architecture specific ones
+#define AARCH64_DYNAMIC_TAG(name, value)
+#define MIPS_DYNAMIC_TAG(name, value)
+#define HEXAGON_DYNAMIC_TAG(name, value)
+#define PPC64_DYNAMIC_TAG(name, value)
+// Also ignore marker tags such as DT_HIOS (maps to DT_VERNEEDNUM), etc.
+#define DYNAMIC_TAG_MARKER(name, value)
+#define DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value)
+#include "llvm/BinaryFormat/DynamicTags.def"
+#undef DYNAMIC_TAG
+#undef AARCH64_DYNAMIC_TAG
+#undef MIPS_DYNAMIC_TAG
+#undef HEXAGON_DYNAMIC_TAG
+#undef PPC64_DYNAMIC_TAG
+#undef DYNAMIC_TAG_MARKER
+#undef DYNAMIC_STRINGIFY_ENUM
+  default:
+    return "<unknown:>0x" + utohexstr(Type, true);
+  }
+}
+
+template <class ELFT>
+std::string ELFFile<ELFT>::getDynamicTagAsString(uint64_t Type) const {
+  return getDynamicTagAsString(getHeader()->e_machine, Type);
+}
+
+template <class ELFT>
+Expected<typename ELFT::DynRange> ELFFile<ELFT>::dynamicEntries() const {
+  ArrayRef<Elf_Dyn> Dyn;
+  size_t DynSecSize = 0;
+
+  auto ProgramHeadersOrError = program_headers();
+  if (!ProgramHeadersOrError)
+    return ProgramHeadersOrError.takeError();
+
+  for (const Elf_Phdr &Phdr : *ProgramHeadersOrError) {
+    if (Phdr.p_type == ELF::PT_DYNAMIC) {
+      Dyn = makeArrayRef(
+          reinterpret_cast<const Elf_Dyn *>(base() + Phdr.p_offset),
+          Phdr.p_filesz / sizeof(Elf_Dyn));
+      DynSecSize = Phdr.p_filesz;
+      break;
+    }
+  }
+
+  // If we can't find the dynamic section in the program headers, we just fall
+  // back on the sections.
+  if (Dyn.empty()) {
+    auto SectionsOrError = sections();
+    if (!SectionsOrError)
+      return SectionsOrError.takeError();
+
+    for (const Elf_Shdr &Sec : *SectionsOrError) {
+      if (Sec.sh_type == ELF::SHT_DYNAMIC) {
+        Expected<ArrayRef<Elf_Dyn>> DynOrError =
+            getSectionContentsAsArray<Elf_Dyn>(&Sec);
+        if (!DynOrError)
+          return DynOrError.takeError();
+        Dyn = *DynOrError;
+        DynSecSize = Sec.sh_size;
+        break;
+      }
+    }
+
+    if (!Dyn.data())
+      return ArrayRef<Elf_Dyn>();
+  }
+
+  if (Dyn.empty())
+    // TODO: this error is untested.
+    return createError("invalid empty dynamic section");
+
+  if (DynSecSize % sizeof(Elf_Dyn) != 0)
+    // TODO: this error is untested.
+    return createError("malformed dynamic section");
+
+  if (Dyn.back().d_tag != ELF::DT_NULL)
+    // TODO: this error is untested.
+    return createError("dynamic sections must be DT_NULL terminated");
+
+  return Dyn;
+}
+
+template <class ELFT>
+Expected<const uint8_t *> ELFFile<ELFT>::toMappedAddr(uint64_t VAddr) const {
+  auto ProgramHeadersOrError = program_headers();
+  if (!ProgramHeadersOrError)
+    return ProgramHeadersOrError.takeError();
+
+  llvm::SmallVector<Elf_Phdr *, 4> LoadSegments;
+
+  for (const Elf_Phdr &Phdr : *ProgramHeadersOrError)
+    if (Phdr.p_type == ELF::PT_LOAD)
+      LoadSegments.push_back(const_cast<Elf_Phdr *>(&Phdr));
+
+  const Elf_Phdr *const *I =
+      std::upper_bound(LoadSegments.begin(), LoadSegments.end(), VAddr,
+                       [](uint64_t VAddr, const Elf_Phdr_Impl<ELFT> *Phdr) {
+                         return VAddr < Phdr->p_vaddr;
+                       });
+
+  if (I == LoadSegments.begin())
+    return createError("virtual address is not in any segment: 0x" +
+                       Twine::utohexstr(VAddr));
+  --I;
+  const Elf_Phdr &Phdr = **I;
+  uint64_t Delta = VAddr - Phdr.p_vaddr;
+  if (Delta >= Phdr.p_filesz)
+    return createError("virtual address is not in any segment: 0x" +
+                       Twine::utohexstr(VAddr));
+  return base() + Phdr.p_offset + Delta;
+}
+
 template class llvm::object::ELFFile<ELF32LE>;
 template class llvm::object::ELFFile<ELF32BE>;
 template class llvm::object::ELFFile<ELF64LE>;