[llvm] r337902 - [llvm-objdump] Add dynamic section printing to private-headers option

Paul Semel via llvm-commits llvm-commits at lists.llvm.org
Wed Jul 25 04:09:20 PDT 2018


Author: paulsemel
Date: Wed Jul 25 04:09:20 2018
New Revision: 337902

URL: http://llvm.org/viewvc/llvm-project?rev=337902&view=rev
Log:
[llvm-objdump] Add dynamic section printing to private-headers option

Differential Revision: https://reviews.llvm.org/D49016

Added:
    llvm/trunk/test/tools/llvm-objdump/Inputs/private-headers-x86_64.elf   (with props)
    llvm/trunk/test/tools/llvm-objdump/private-headers-dynamic-section.test
    llvm/trunk/test/tools/llvm-objdump/private-headers-no-dynamic-segment.test
    llvm/trunk/test/tools/llvm-objdump/private-headers-no-dynamic.test
Modified:
    llvm/trunk/include/llvm/Object/ELF.h
    llvm/trunk/lib/Object/ELF.cpp
    llvm/trunk/tools/llvm-objdump/ELFDump.cpp
    llvm/trunk/tools/llvm-objdump/llvm-objdump.cpp
    llvm/trunk/tools/llvm-objdump/llvm-objdump.h

Modified: llvm/trunk/include/llvm/Object/ELF.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Object/ELF.h?rev=337902&r1=337901&r2=337902&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Object/ELF.h (original)
+++ llvm/trunk/include/llvm/Object/ELF.h Wed Jul 25 04:09:20 2018
@@ -115,6 +115,9 @@ public:
                              SmallVectorImpl<char> &Result) const;
   uint32_t getRelrRelocationType() const;
 
+  const char *getDynamicTagAsString(unsigned Arch, uint64_t Type) const;
+  const char *getDynamicTagAsString(uint64_t Type) const;
+
   /// Get the symbol for a given relocation.
   Expected<const Elf_Sym *> getRelocationSymbol(const Elf_Rel *Rel,
                                                 const Elf_Shdr *SymTab) const;
@@ -133,6 +136,10 @@ public:
 
   Expected<Elf_Shdr_Range> sections() const;
 
+  Expected<Elf_Dyn_Range> dynamicEntries() const;
+
+  Expected<const uint8_t *> toMappedAddr(uint64_t VAddr) const;
+
   Expected<Elf_Sym_Range> symbols(const Elf_Shdr *Sec) const {
     if (!Sec)
       return makeArrayRef<Elf_Sym>(nullptr, nullptr);

Modified: llvm/trunk/lib/Object/ELF.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Object/ELF.cpp?rev=337902&r1=337901&r2=337902&view=diff
==============================================================================
--- llvm/trunk/lib/Object/ELF.cpp (original)
+++ llvm/trunk/lib/Object/ELF.cpp Wed Jul 25 04:09:20 2018
@@ -420,6 +420,144 @@ ELFFile<ELFT>::android_relas(const Elf_S
   return Relocs;
 }
 
+template <class ELFT>
+const char *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_HEXAGON:
+    switch (Type) {
+#define HEXAGON_DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value)
+#include "llvm/BinaryFormat/DynamicTags.def"
+#undef HEXAGON_DYNAMIC_TAG
+    }
+
+  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
+    }
+
+  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
+    }
+  }
+#undef DYNAMIC_TAG
+  switch (Type) {
+// Now handle all dynamic tags except the architecture specific ones
+#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 MIPS_DYNAMIC_TAG
+#undef HEXAGON_DYNAMIC_TAG
+#undef PPC64_DYNAMIC_TAG
+#undef DYNAMIC_TAG_MARKER
+#undef DYNAMIC_STRINGIFY_ENUM
+  default:
+    return "unknown";
+  }
+}
+
+template <class ELFT>
+const char *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())
+    return createError("invalid empty dynamic section");
+
+  if (DynSecSize % sizeof(Elf_Dyn) != 0)
+    return createError("malformed dynamic section");
+
+  if (Dyn.back().d_tag != ELF::DT_NULL)
+    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");
+  --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");
+  return base() + Phdr.p_offset + Delta;
+}
+
 template class llvm::object::ELFFile<ELF32LE>;
 template class llvm::object::ELFFile<ELF32BE>;
 template class llvm::object::ELFFile<ELF64LE>;

Added: llvm/trunk/test/tools/llvm-objdump/Inputs/private-headers-x86_64.elf
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-objdump/Inputs/private-headers-x86_64.elf?rev=337902&view=auto
==============================================================================
Binary files llvm/trunk/test/tools/llvm-objdump/Inputs/private-headers-x86_64.elf (added) and llvm/trunk/test/tools/llvm-objdump/Inputs/private-headers-x86_64.elf Wed Jul 25 04:09:20 2018 differ

Propchange: llvm/trunk/test/tools/llvm-objdump/Inputs/private-headers-x86_64.elf
------------------------------------------------------------------------------
    svn:executable = *

Added: llvm/trunk/test/tools/llvm-objdump/private-headers-dynamic-section.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-objdump/private-headers-dynamic-section.test?rev=337902&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-objdump/private-headers-dynamic-section.test (added)
+++ llvm/trunk/test/tools/llvm-objdump/private-headers-dynamic-section.test Wed Jul 25 04:09:20 2018
@@ -0,0 +1,35 @@
+# RUN: llvm-objdump -p %p/Inputs/private-headers-x86_64.elf | FileCheck %s
+# RUN: llvm-objcopy --strip-sections %p/Inputs/private-headers-x86_64.elf %t
+# RUN: llvm-objdump -p %t | FileCheck %s
+
+# CHECK:  NEEDED               libstdc++.so.6
+# CHECK:  NEEDED               libm.so.6
+# CHECK:  NEEDED               libgcc_s.so.1
+# CHECK:  NEEDED               libc.so.6
+# CHECK:  INIT                 0x00000000000006a0
+# CHECK:  FINI                 0x0000000000000924
+# CHECK:  INIT_ARRAY           0x0000000000200da8
+# CHECK:  INIT_ARRAYSZ         0x0000000000000010
+# CHECK:  FINI_ARRAY           0x0000000000200db8
+# CHECK:  FINI_ARRAYSZ         0x0000000000000008
+# CHECK:  GNU_HASH             0x0000000000000298
+# CHECK:  STRTAB               0x00000000000003c8
+# CHECK:  SYMTAB               0x00000000000002c0
+# CHECK:  STRSZ                0x000000000000012f
+# CHECK:  SYMENT               0x0000000000000018
+# CHECK:  DEBUG                0x0000000000000000
+# CHECK:  PLTGOT               0x0000000000201000
+# CHECK:  PLTRELSZ             0x0000000000000048
+# CHECK:  PLTREL               0x0000000000000007
+# CHECK:  JMPREL               0x0000000000000658
+# CHECK:  RELA                 0x0000000000000550
+# CHECK:  RELASZ               0x0000000000000108
+# CHECK:  RELAENT              0x0000000000000018
+# CHECK:  FLAGS_1              0x0000000008000000
+# CHECK:  VERNEED              0x0000000000000510
+# CHECK:  VERNEEDNUM           0x0000000000000002
+# CHECK:  VERSYM               0x00000000000004f8
+# CHECK:  RELACOUNT            0x0000000000000004
+# CHECK:  RELRSZ               0x0000000000000014
+# CHECK:  RELR                 0x0000000087654321
+# CHECK:  RELRENT              0x0000000000000010

Added: llvm/trunk/test/tools/llvm-objdump/private-headers-no-dynamic-segment.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-objdump/private-headers-no-dynamic-segment.test?rev=337902&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-objdump/private-headers-no-dynamic-segment.test (added)
+++ llvm/trunk/test/tools/llvm-objdump/private-headers-no-dynamic-segment.test Wed Jul 25 04:09:20 2018
@@ -0,0 +1,42 @@
+# RUN: yaml2obj %s > %t
+# RUN: llvm-objdump -p %t | FileCheck %s
+
+!ELF
+FileHeader:
+  Class:           ELFCLASS64
+  Data:            ELFDATA2LSB
+  Type:            ET_REL
+  Machine:         EM_X86_64
+Sections:
+  - Name:            .dynamic
+    Type:            SHT_DYNAMIC
+    Flags:           [ SHF_ALLOC, SHF_WRITE ]
+    Content: 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
+
+# CHECK:  INIT                 0x00000000000006a0
+# CHECK:  FINI                 0x0000000000000924
+# CHECK:  INIT_ARRAY           0x0000000000200da8
+# CHECK:  INIT_ARRAYSZ         0x0000000000000010
+# CHECK:  FINI_ARRAY           0x0000000000200db8
+# CHECK:  FINI_ARRAYSZ         0x0000000000000008
+# CHECK:  GNU_HASH             0x0000000000000298
+# CHECK:  STRTAB               0x00000000000003c8
+# CHECK:  SYMTAB               0x00000000000002c0
+# CHECK:  STRSZ                0x000000000000012f
+# CHECK:  SYMENT               0x0000000000000018
+# CHECK:  DEBUG                0x0000000000000000
+# CHECK:  PLTGOT               0x0000000000201000
+# CHECK:  PLTRELSZ             0x0000000000000048
+# CHECK:  PLTREL               0x0000000000000007
+# CHECK:  JMPREL               0x0000000000000658
+# CHECK:  RELA                 0x0000000000000550
+# CHECK:  RELASZ               0x0000000000000108
+# CHECK:  RELAENT              0x0000000000000018
+# CHECK:  FLAGS_1              0x0000000008000000
+# CHECK:  VERNEED              0x0000000000000510
+# CHECK:  VERNEEDNUM           0x0000000000000002
+# CHECK:  VERSYM               0x00000000000004f8
+# CHECK:  RELACOUNT            0x0000000000000004
+# CHECK:  RELRSZ               0x0000000000000014
+# CHECK:  RELR                 0x0000000087654321
+# CHECK:  RELRENT              0x0000000000000010

Added: llvm/trunk/test/tools/llvm-objdump/private-headers-no-dynamic.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-objdump/private-headers-no-dynamic.test?rev=337902&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-objdump/private-headers-no-dynamic.test (added)
+++ llvm/trunk/test/tools/llvm-objdump/private-headers-no-dynamic.test Wed Jul 25 04:09:20 2018
@@ -0,0 +1,19 @@
+# RUN: yaml2obj %s > %t
+# RUN: llvm-objdump -p %t | FileCheck %s
+
+!ELF
+FileHeader:
+  Class:           ELFCLASS64
+  Data:            ELFDATA2LSB
+  Type:            ET_REL
+  Machine:         EM_X86_64
+Sections:
+  - Name:            .text
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    Address:         0x1000
+    AddressAlign:    0x0000000000000010
+    Size:            64
+
+# CHECK: Dynamic Section:
+# CHECK-NOT: {{.}}

Modified: llvm/trunk/tools/llvm-objdump/ELFDump.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objdump/ELFDump.cpp?rev=337902&r1=337901&r2=337902&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-objdump/ELFDump.cpp (original)
+++ llvm/trunk/tools/llvm-objdump/ELFDump.cpp Wed Jul 25 04:09:20 2018
@@ -21,6 +21,77 @@
 using namespace llvm;
 using namespace llvm::object;
 
+template <class ELFT>
+Expected<StringRef> getDynamicStrTab(const ELFFile<ELFT> *Elf) {
+  typedef ELFFile<ELFT> ELFO;
+
+  auto DynamicEntriesOrError = Elf->dynamicEntries();
+  if (!DynamicEntriesOrError)
+    return DynamicEntriesOrError.takeError();
+
+  for (const typename ELFO::Elf_Dyn &Dyn : *DynamicEntriesOrError) {
+    if (Dyn.d_tag == ELF::DT_STRTAB) {
+      auto MappedAddrOrError = Elf->toMappedAddr(Dyn.getPtr());
+      if (!MappedAddrOrError)
+        consumeError(MappedAddrOrError.takeError());
+      return StringRef(reinterpret_cast<const char *>(*MappedAddrOrError));
+    }
+  }
+
+  // If the dynamic segment is not present, we fall back on the sections.
+  auto SectionsOrError = Elf->sections();
+  if (!SectionsOrError)
+    return SectionsOrError.takeError();
+
+  for (const typename ELFO::Elf_Shdr &Sec : *SectionsOrError) {
+    if (Sec.sh_type == ELF::SHT_DYNSYM)
+      return Elf->getStringTableForSymtab(Sec);
+  }
+
+  return createError("dynamic string table not found");
+}
+
+template <class ELFT>
+void printDynamicSection(const ELFFile<ELFT> *Elf, StringRef Filename) {
+  auto ProgramHeaderOrError = Elf->program_headers();
+  if (!ProgramHeaderOrError)
+    report_error(Filename, ProgramHeaderOrError.takeError());
+
+  auto DynamicEntriesOrError = Elf->dynamicEntries();
+  if (!DynamicEntriesOrError)
+    report_error(Filename, DynamicEntriesOrError.takeError());
+
+  outs() << "Dynamic Section:\n";
+  for (const auto &Dyn : *DynamicEntriesOrError) {
+    if (Dyn.d_tag == ELF::DT_NULL)
+      continue;
+
+    StringRef Str = StringRef(Elf->getDynamicTagAsString(Dyn.d_tag));
+
+    if (Str.empty()) {
+      std::string HexStr = utohexstr(static_cast<uint64_t>(Dyn.d_tag), true);
+      outs() << format("  0x%-19s", HexStr.c_str());
+    } else {
+      // We use "-21" in order to match GNU objdump's output.
+      outs() << format("  %-21s", Str.data());
+    }
+
+    const char *Fmt =
+        ELFT::Is64Bits ? "0x%016" PRIx64 "\n" : "0x%08" PRIx64 "\n";
+    if (Dyn.d_tag == ELF::DT_NEEDED) {
+      Expected<StringRef> StrTabOrErr = getDynamicStrTab(Elf);
+      if (StrTabOrErr) {
+        const char *Data = StrTabOrErr.get().data();
+        outs() << (Data + Dyn.d_un.d_val) << "\n";
+        continue;
+      }
+      warn(errorToErrorCode(StrTabOrErr.takeError()).message());
+      consumeError(StrTabOrErr.takeError());
+    }
+    outs() << format(Fmt, (uint64_t)Dyn.d_un.d_val);
+  }
+}
+
 template <class ELFT> void printProgramHeaders(const ELFFile<ELFT> *o) {
   typedef ELFFile<ELFT> ELFO;
   outs() << "Program Header:\n";
@@ -103,3 +174,21 @@ void llvm::printELFFileHeader(const obje
   if (const ELF64BEObjectFile *ELFObj = dyn_cast<ELF64BEObjectFile>(Obj))
     printProgramHeaders(ELFObj->getELFFile());
 }
+
+void llvm::printELFDynamicSection(const object::ObjectFile *Obj) {
+  // Little-endian 32-bit
+  if (const ELF32LEObjectFile *ELFObj = dyn_cast<ELF32LEObjectFile>(Obj))
+    printDynamicSection(ELFObj->getELFFile(), Obj->getFileName());
+
+  // Big-endian 32-bit
+  if (const ELF32BEObjectFile *ELFObj = dyn_cast<ELF32BEObjectFile>(Obj))
+    printDynamicSection(ELFObj->getELFFile(), Obj->getFileName());
+
+  // Little-endian 64-bit
+  if (const ELF64LEObjectFile *ELFObj = dyn_cast<ELF64LEObjectFile>(Obj))
+    printDynamicSection(ELFObj->getELFFile(), Obj->getFileName());
+
+  // Big-endian 64-bit
+  if (const ELF64BEObjectFile *ELFObj = dyn_cast<ELF64BEObjectFile>(Obj))
+    printDynamicSection(ELFObj->getELFFile(), Obj->getFileName());
+}

Modified: llvm/trunk/tools/llvm-objdump/llvm-objdump.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objdump/llvm-objdump.cpp?rev=337902&r1=337901&r2=337902&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-objdump/llvm-objdump.cpp (original)
+++ llvm/trunk/tools/llvm-objdump/llvm-objdump.cpp Wed Jul 25 04:09:20 2018
@@ -2153,8 +2153,10 @@ static void printFaultMaps(const ObjectF
 }
 
 static void printPrivateFileHeaders(const ObjectFile *o, bool onlyFirst) {
-  if (o->isELF())
-    return printELFFileHeader(o);
+  if (o->isELF()) {
+    printELFFileHeader(o);
+    return printELFDynamicSection(o);
+  }
   if (o->isCOFF())
     return printCOFFFileHeader(o);
   if (o->isWasm())

Modified: llvm/trunk/tools/llvm-objdump/llvm-objdump.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objdump/llvm-objdump.h?rev=337902&r1=337901&r2=337902&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-objdump/llvm-objdump.h (original)
+++ llvm/trunk/tools/llvm-objdump/llvm-objdump.h Wed Jul 25 04:09:20 2018
@@ -79,6 +79,7 @@ void printMachOBindTable(object::MachOOb
 void printMachOLazyBindTable(object::MachOObjectFile* o);
 void printMachOWeakBindTable(object::MachOObjectFile* o);
 void printELFFileHeader(const object::ObjectFile *o);
+void printELFDynamicSection(const object::ObjectFile *Obj);
 void printCOFFFileHeader(const object::ObjectFile *o);
 void printCOFFSymbolTable(const object::COFFImportFile *i);
 void printCOFFSymbolTable(const object::COFFObjectFile *o);




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