[ELF] - Round executable PT_LOAD to page size and pad it with traps

[grimar]

Summary

This is PR33819,

Patch attempts to simplify outdated D33630.

[grimar]

• Rebased.
• Simplified.

[grimar]

r309829

[joerg]

I'm not sure I want anything like this unconditionally. It is going to waste quite a bit of space, i.e. 2KB per executable and shared library sums up.

[grimar]

In D35680#830334, @joerg wrote:

I'm not sure I want anything like this unconditionally. It is going to waste quite a bit of space, i.e. 2KB per executable and shared library sums up.

Just in case: this patch was abandoned, D33630 was landed. It do something about the same though, but probably more correct to discuss in its thread.

ELF/InputSection.cpp

 // The ARM ABI defines base to be "addressing origin of the output segment
 // defining the symbol S". We defined the "addressing origin"/static base to be
 // the base of the PT_LOAD segment containing the Body.
 // The procedure call standard only defines a Read Write Position Independent
 // RWPI variant so in practice we should expect the static base to be the base
 // of the RW segment.
 static uint64_t getARMStaticBase(const SymbolBody &Body) {
   OutputSection *OS = Body.getOutputSection();
-  if (!OS || !OS->FirstInPtLoad)
+  if (!OS || !OS->Load || !OS->Load->First)
     fatal("SBREL relocation to " + Body.getName() + " without static base");
-  return OS->FirstInPtLoad->Addr;
+  return OS->Load->First->Addr;
 }
 
 static uint64_t getRelocTargetVA(uint32_t Type, int64_t A, uint64_t P,
                                  const SymbolBody &Body, RelExpr Expr) {
   switch (Expr) {
   case R_ABS:
   case R_RELAX_GOT_PC_NOPIC:
     return Body.getVA(A);

ELF/LinkerScript.h

public:
   bool isDefined(StringRef S);
 
   void fabricateDefaultCommands();
   void addOrphanSections(OutputSectionFactory &Factory);
   void removeEmptyCommands();
   void adjustSectionsBeforeSorting();
   void adjustSectionsAfterSorting();
 
-  std::vector<PhdrEntry> createPhdrs();
+  std::vector<PhdrEntry *> createPhdrs();
   bool ignoreInterpSection();
 
   bool shouldKeep(InputSectionBase *S);
   void assignOffsets(OutputSectionCommand *Cmd);
   void processNonSectionCommands();
   void assignAddresses();
-  void allocateHeaders(std::vector<PhdrEntry> &Phdrs);
+  void allocateHeaders(std::vector<PhdrEntry *> &Phdrs);
   void addSymbol(SymbolAssignment *Cmd);
   void processCommands(OutputSectionFactory &Factory);
 
   // Parsed linker script configurations are set to this struct.
   ScriptConfiguration Opt;
 };
 
 extern LinkerScript *Script;
 
 } // end namespace elf
+
+void fill(uint8_t *Buf, size_t Size, uint32_t Filler);
+
 } // end namespace lld
 
 #endif // LLD_ELF_LINKER_SCRIPT_H

ELF/LinkerScript.cpp

 }
 
 bool OutputSectionCommand::classof(const BaseCommand *C) {
   return C->Kind == OutputSectionKind;
 }
 
 // Fill [Buf, Buf + Size) with Filler.
 // This is used for linker script "=fillexp" command.
-static void fill(uint8_t *Buf, size_t Size, uint32_t Filler) {
+void lld::fill(uint8_t *Buf, size_t Size, uint32_t Filler) {
   size_t I = 0;
   for (; I + 4 < Size; I += 4)
     memcpy(Buf + I, &Filler, 4);
   memcpy(Buf + I, &Filler, Size - I);
 }
 
 bool InputSectionDescription::classof(const BaseCommand *C) {
   return C->Kind == InputSectionKind;
void LinkerScript::processNonSectionCommands() {
   for (BaseCommand *Base : Opt.Commands) {
     if (auto *Cmd = dyn_cast<SymbolAssignment>(Base))
       assignSymbol(Cmd, false);
     else if (auto *Cmd = dyn_cast<AssertCommand>(Base))
       Cmd->Expression();
   }
 }
 
-void LinkerScript::allocateHeaders(std::vector<PhdrEntry> &Phdrs) {
+static OutputSection *getFirstSection(PhdrEntry *Load) {
+  for (OutputSectionCommand *Cmd : OutputSectionCommands)
+    if (Cmd->Sec->Load == Load)
+      return Cmd->Sec;
+  return nullptr;
+}
+
+void LinkerScript::allocateHeaders(std::vector<PhdrEntry *> &Phdrs) {
   uint64_t Min = std::numeric_limits<uint64_t>::max();
   for (OutputSectionCommand *Cmd : OutputSectionCommands) {
     OutputSection *Sec = Cmd->Sec;
     if (Sec->Flags & SHF_ALLOC)
       Min = std::min<uint64_t>(Min, Sec->Addr);
   }
 
-  auto FirstPTLoad = llvm::find_if(
-      Phdrs, [](const PhdrEntry &E) { return E.p_type == PT_LOAD; });
-  if (FirstPTLoad == Phdrs.end())
+  auto LoadI = llvm::find_if(
+      Phdrs, [](const PhdrEntry *E) { return E->p_type == PT_LOAD; });
+  if (LoadI == Phdrs.end())
     return;
 
   uint64_t HeaderSize = getHeaderSize();
   if (HeaderSize <= Min || Script->hasPhdrsCommands()) {
     Min = alignDown(Min - HeaderSize, Config->MaxPageSize);
     Out::ElfHeader->Addr = Min;
     Out::ProgramHeaders->Addr = Min + Out::ElfHeader->Size;
     return;
   }
 
-  assert(FirstPTLoad->First == Out::ElfHeader);
-  OutputSection *ActualFirst = nullptr;
-  for (OutputSectionCommand *Cmd : OutputSectionCommands) {
-    OutputSection *Sec = Cmd->Sec;
-    if (Sec->FirstInPtLoad == Out::ElfHeader) {
-      ActualFirst = Sec;
-      break;
-    }
-  }
-  if (ActualFirst) {
-    for (OutputSectionCommand *Cmd : OutputSectionCommands) {
-      OutputSection *Sec = Cmd->Sec;
-      if (Sec->FirstInPtLoad == Out::ElfHeader)
-        Sec->FirstInPtLoad = ActualFirst;
-    }
-    FirstPTLoad->First = ActualFirst;
-  } else {
-    Phdrs.erase(FirstPTLoad);
-  }
+  assert((*LoadI)->First == Out::ElfHeader);
+  Out::ElfHeader->Load = nullptr;
+  Out::ProgramHeaders->Load = nullptr;
+  (*LoadI)->First = getFirstSection(*LoadI);
 
   auto PhdrI = llvm::find_if(
-      Phdrs, [](const PhdrEntry &E) { return E.p_type == PT_PHDR; });
+      Phdrs, [](const PhdrEntry *E) { return E->p_type == PT_PHDR; });
   if (PhdrI != Phdrs.end())
     Phdrs.erase(PhdrI);
 }
 
 LinkerScript::AddressState::AddressState(const ScriptConfiguration &Opt) {
   for (auto &MRI : Opt.MemoryRegions) {
     const MemoryRegion *MR = &MRI.second;
     MemRegionOffset[MR] = MR->Origin;
for (BaseCommand *Base : Opt.Commands) {
 
     auto *Cmd = cast<OutputSectionCommand>(Base);
     assignOffsets(Cmd);
   }
   CurAddressState = nullptr;
 }
 
 // Creates program headers as instructed by PHDRS linker script command.
-std::vector<PhdrEntry> LinkerScript::createPhdrs() {
-  std::vector<PhdrEntry> Ret;
+std::vector<PhdrEntry *> LinkerScript::createPhdrs() {
+  std::vector<PhdrEntry *> Ret;
 
   // Process PHDRS and FILEHDR keywords because they are not
   // real output sections and cannot be added in the following loop.
   for (const PhdrsCommand &Cmd : Opt.PhdrsCommands) {
-    Ret.emplace_back(Cmd.Type, Cmd.Flags == UINT_MAX ? PF_R : Cmd.Flags);
-    PhdrEntry &Phdr = Ret.back();
+    PhdrEntry *Phdr =
+        make<PhdrEntry>(Cmd.Type, Cmd.Flags == UINT_MAX ? PF_R : Cmd.Flags);
 
     if (Cmd.HasFilehdr)
-      Phdr.add(Out::ElfHeader);
+      Phdr->add(Out::ElfHeader);
     if (Cmd.HasPhdrs)
-      Phdr.add(Out::ProgramHeaders);
+      Phdr->add(Out::ProgramHeaders);
 
     if (Cmd.LMAExpr) {
-      Phdr.p_paddr = Cmd.LMAExpr().getValue();
-      Phdr.HasLMA = true;
+      Phdr->p_paddr = Cmd.LMAExpr().getValue();
+      Phdr->HasLMA = true;
     }
+    Ret.push_back(Phdr);
   }
 
   // Add output sections to program headers.
   for (OutputSectionCommand *Cmd : OutputSectionCommands) {
     // Assign headers specified by linker script
     for (size_t Id : getPhdrIndices(Cmd)) {
       OutputSection *Sec = Cmd->Sec;
-      Ret[Id].add(Sec);
+      Ret[Id]->add(Sec);
       if (Opt.PhdrsCommands[Id].Flags == UINT_MAX)
-        Ret[Id].p_flags |= Sec->getPhdrFlags();
+        Ret[Id]->p_flags |= Sec->getPhdrFlags();
     }
   }
   return Ret;
 }
 
 bool LinkerScript::ignoreInterpSection() {
   // Ignore .interp section in case we have PHDRS specification
   // and PT_INTERP isn't listed.

ELF/OutputSections.h

public:
 
   uint32_t getPhdrFlags() const;
 
   void updateAlignment(uint32_t Val) {
     if (Val > Alignment)
       Alignment = Val;
   }
 
-  // Pointer to the first section in PT_LOAD segment, which this section
-  // also resides in. This field is used to correctly compute file offset
-  // of a section. When two sections share the same load segment, difference
-  // between their file offsets should be equal to difference between their
-  // virtual addresses. To compute some section offset we use the following
-  // formula: Off = Off_first + VA - VA_first.
-  OutputSection *FirstInPtLoad = nullptr;
+  // Pointer to the PT_LOAD segment, which this section resides in. This field
+  // is used to correctly compute file offset of a section. When two sections
+  // share the same load segment, difference between their file offsets should
+  // be equal to difference between their virtual addresses. To compute some
+  // section offset we use the following formula: Off = Off_first + VA -
+  // VA_first, where Off_first and VA_first is file offset and VA of first
+  // section in PT_LOAD.
+  PhdrEntry *Load = nullptr;
 
   // Pointer to a relocation section for this section. Usually nullptr because
   // we consume relocations, but if --emit-relocs is specified (which is rare),
   // it may have a non-null value.
   OutputSection *RelocationSection = nullptr;
 
   // The following fields correspond to Elf_Shdr members.
   uint64_t Size = 0;

ELF/Writer.cpp

private:
   void addSectionSymbols();
   void addReservedSymbols();
   void createSections();
   void forEachRelSec(std::function<void(InputSectionBase &)> Fn);
   void sortSections();
   void finalizeSections();
   void addPredefinedSections();
 
-  std::vector<PhdrEntry> createPhdrs();
+  std::vector<PhdrEntry *> createPhdrs();
   void removeEmptyPTLoad();
-  void addPtArmExid(std::vector<PhdrEntry> &Phdrs);
+  void addPtArmExid(std::vector<PhdrEntry *> &Phdrs);
   void assignFileOffsets();
   void assignFileOffsetsBinary();
   void setPhdrs();
   void fixSectionAlignments();
   void fixPredefinedSymbols();
   void openFile();
+  void writeTrapInstr();
   void writeHeader();
   void writeSections();
   void writeSectionsBinary();
   void writeBuildId();
 
   std::unique_ptr<FileOutputBuffer> Buffer;
 
   OutputSectionFactory Factory;
 
   void addRelIpltSymbols();
   void addStartEndSymbols();
   void addStartStopSymbols(OutputSection *Sec);
   uint64_t getEntryAddr();
   OutputSection *findSectionInScript(StringRef Name);
   OutputSectionCommand *findSectionCommand(StringRef Name);
 
-  std::vector<PhdrEntry> Phdrs;
+  std::vector<PhdrEntry *> Phdrs;
 
   uint64_t FileSize;
   uint64_t SectionHeaderOff;
 
   bool HasGotBaseSym = false;
 };
 } // anonymous namespace
 

 template <class ELFT> static bool needsInterpSection() {
   return !Symtab<ELFT>::X->getSharedFiles().empty() &&
          !Config->DynamicLinker.empty() && !Script->ignoreInterpSection();
 }
 
 template <class ELFT> void elf::writeResult() { Writer<ELFT>().run(); }
 
 template <class ELFT> void Writer<ELFT>::removeEmptyPTLoad() {
-  auto I = std::remove_if(Phdrs.begin(), Phdrs.end(), [&](const PhdrEntry &P) {
-    if (P.p_type != PT_LOAD)
+  auto I = llvm::remove_if(Phdrs, [&](const PhdrEntry *P) {
+    if (P->p_type != PT_LOAD)
       return false;
-    if (!P.First)
+    if (!P->First)
       return true;
-    uint64_t Size = P.Last->Addr + P.Last->Size - P.First->Addr;
+    uint64_t Size = P->Last->Addr + P->Last->Size - P->First->Addr;
     return Size == 0;
   });
   Phdrs.erase(I, Phdrs.end());
 }
 
 template <class ELFT> static void combineEhFrameSections() {
   for (InputSectionBase *&S : InputSections) {
     EhInputSection *ES = dyn_cast<EhInputSection>(S);
template <class ELFT> void Writer<ELFT>::run() {
   if (ErrorCount)
     return;
   // Write the result down to a file.
   openFile();
   if (ErrorCount)
     return;
 
   if (!Config->OFormatBinary) {
+    writeTrapInstr();
     writeHeader();
     writeSections();
   } else {
     writeSectionsBinary();
   }
 
   // Backfill .note.gnu.build-id section content. This is done at last
   // because the content is usually a hash value of the entire output file.

 }
 
 void PhdrEntry::add(OutputSection *Sec) {
   Last = Sec;
   if (!First)
     First = Sec;
   p_align = std::max(p_align, Sec->Alignment);
   if (p_type == PT_LOAD)
-    Sec->FirstInPtLoad = First;
+    Sec->Load = this;
 }
 
 template <class ELFT>
 static Symbol *addRegular(StringRef Name, SectionBase *Sec, uint64_t Value,
                           uint8_t StOther = STV_HIDDEN,
                           uint8_t Binding = STB_WEAK) {
   // The linker generated symbols are added as STB_WEAK to allow user defined
   // ones to override them.
if (Config->Omagic)
     return PF_R | PF_W | PF_X;
   if (Config->SingleRoRx && !(Flags & PF_W))
     return Flags | PF_X;
   return Flags;
 }
 
 // Decide which program headers to create and which sections to include in each
 // one.
-template <class ELFT> std::vector<PhdrEntry> Writer<ELFT>::createPhdrs() {
-  std::vector<PhdrEntry> Ret;
+template <class ELFT> std::vector<PhdrEntry *> Writer<ELFT>::createPhdrs() {
+  std::vector<PhdrEntry *> Ret;
   auto AddHdr = [&](unsigned Type, unsigned Flags) -> PhdrEntry * {
-    Ret.emplace_back(Type, Flags);
-    return &Ret.back();
+    Ret.push_back(make<PhdrEntry>(Type, Flags));
+    return Ret.back();
   };
 
   // The first phdr entry is PT_PHDR which describes the program header itself.
   AddHdr(PT_PHDR, PF_R)->add(Out::ProgramHeaders);
 
   // PT_INTERP must be the second entry if exists.
   if (OutputSection *Sec = findSectionInScript(".interp"))
     AddHdr(PT_INTERP, Sec->getPhdrFlags())->add(Sec);
if (Cmd->LMAExpr || Flags != NewFlags) {
       Load = AddHdr(PT_LOAD, NewFlags);
       Flags = NewFlags;
     }
 
     Load->add(Sec);
   }
 
   // Add a TLS segment if any.
-  PhdrEntry TlsHdr(PT_TLS, PF_R);
+  PhdrEntry *TlsHdr = make<PhdrEntry>(PT_TLS, PF_R);
   for (OutputSectionCommand *Cmd : OutputSectionCommands) {
     OutputSection *Sec = Cmd->Sec;
     if (Sec->Flags & SHF_TLS)
-      TlsHdr.add(Sec);
+      TlsHdr->add(Sec);
   }
-  if (TlsHdr.First)
-    Ret.push_back(std::move(TlsHdr));
+  if (TlsHdr->First)
+    Ret.push_back(TlsHdr);
 
   // Add an entry for .dynamic.
   if (InX::DynSymTab)
     AddHdr(PT_DYNAMIC, InX::Dynamic->getParent()->getPhdrFlags())
         ->add(InX::Dynamic->getParent());
 
   // PT_GNU_RELRO includes all sections that should be marked as
   // read-only by dynamic linker after proccessing relocations.
-  PhdrEntry RelRo(PT_GNU_RELRO, PF_R);
+  PhdrEntry *RelRo = make<PhdrEntry>(PT_GNU_RELRO, PF_R);
   for (OutputSectionCommand *Cmd : OutputSectionCommands) {
     OutputSection *Sec = Cmd->Sec;
     if (needsPtLoad(Sec) && isRelroSection(Sec))
-      RelRo.add(Sec);
+      RelRo->add(Sec);
   }
-  if (RelRo.First)
-    Ret.push_back(std::move(RelRo));
+  if (RelRo->First)
+    Ret.push_back(RelRo);
 
   // PT_GNU_EH_FRAME is a special section pointing on .eh_frame_hdr.
   if (!In<ELFT>::EhFrame->empty() && In<ELFT>::EhFrameHdr &&
       In<ELFT>::EhFrame->getParent() && In<ELFT>::EhFrameHdr->getParent())
     AddHdr(PT_GNU_EH_FRAME, In<ELFT>::EhFrameHdr->getParent()->getPhdrFlags())
         ->add(In<ELFT>::EhFrameHdr->getParent());
 
   // PT_OPENBSD_RANDOMIZE is an OpenBSD-specific feature. That makes
for (OutputSectionCommand *Cmd : OutputSectionCommands) {
     } else {
       Note = nullptr;
     }
   }
   return Ret;
 }
 
 template <class ELFT>
-void Writer<ELFT>::addPtArmExid(std::vector<PhdrEntry> &Phdrs) {
+void Writer<ELFT>::addPtArmExid(std::vector<PhdrEntry *> &Phdrs) {
   if (Config->EMachine != EM_ARM)
     return;
   auto I = llvm::find_if(OutputSectionCommands, [](OutputSectionCommand *Cmd) {
     return Cmd->Sec->Type == SHT_ARM_EXIDX;
   });
   if (I == OutputSectionCommands.end())
     return;
 
   // PT_ARM_EXIDX is the ARM EHABI equivalent of PT_GNU_EH_FRAME
-  PhdrEntry ARMExidx(PT_ARM_EXIDX, PF_R);
-  ARMExidx.add((*I)->Sec);
+  PhdrEntry *ARMExidx = make<PhdrEntry>(PT_ARM_EXIDX, PF_R);
+  ARMExidx->add((*I)->Sec);
   Phdrs.push_back(ARMExidx);
 }
 
 // The first section of each PT_LOAD, the first section in PT_GNU_RELRO and the
 // first section after PT_GNU_RELRO have to be page aligned so that the dynamic
 // linker can set the permissions.
 template <class ELFT> void Writer<ELFT>::fixSectionAlignments() {
   auto PageAlign = [](OutputSection *Sec) {
     OutputSectionCommand *Cmd = Script->getCmd(Sec);
     if (Cmd && !Cmd->AddrExpr)
       Cmd->AddrExpr = [=] {
         return alignTo(Script->getDot(), Config->MaxPageSize);
       };
   };
 
-  for (const PhdrEntry &P : Phdrs)
-    if (P.p_type == PT_LOAD && P.First)
-      PageAlign(P.First);
+  for (const PhdrEntry *P : Phdrs)
+    if (P->p_type == PT_LOAD && P->First)
+      PageAlign(P->First);
 
-  for (const PhdrEntry &P : Phdrs) {
-    if (P.p_type != PT_GNU_RELRO)
+  for (const PhdrEntry *P : Phdrs) {
+    if (P->p_type != PT_GNU_RELRO)
       continue;
-    if (P.First)
-      PageAlign(P.First);
+    if (P->First)
+      PageAlign(P->First);
     // Find the first section after PT_GNU_RELRO. If it is in a PT_LOAD we
     // have to align it to a page.
     auto End = OutputSectionCommands.end();
     auto I =
-        std::find(OutputSectionCommands.begin(), End, Script->getCmd(P.Last));
+        std::find(OutputSectionCommands.begin(), End, Script->getCmd(P->Last));
     if (I == End || (I + 1) == End)
       continue;
     OutputSection *Sec = (*(I + 1))->Sec;
     if (needsPtLoad(Sec))
       PageAlign(Sec);
   }
 }
 
 // Adjusts the file alignment for a given output section and returns
 // its new file offset. The file offset must be the same with its
 // virtual address (modulo the page size) so that the loader can load
 // executables without any address adjustment.
 static uint64_t getFileAlignment(uint64_t Off, OutputSection *Sec) {
-  OutputSection *First = Sec->FirstInPtLoad;
+  OutputSection *First = Sec->Load ? Sec->Load->First : nullptr;
   // If the section is not in a PT_LOAD, we just have to align it.
   if (!First)
     return alignTo(Off, Sec->Alignment);
 
   // The first section in a PT_LOAD has to have congruent offset and address
   // module the page size.
   if (Sec == First)
     return alignTo(Off, Config->MaxPageSize, Sec->Addr);
template <class ELFT> void Writer<ELFT>::assignFileOffsetsBinary() {
   for (OutputSectionCommand *Cmd : OutputSectionCommands) {
     OutputSection *Sec = Cmd->Sec;
     if (Sec->Flags & SHF_ALLOC)
       Off = setOffset(Sec, Off);
   }
   FileSize = alignTo(Off, Config->Wordsize);
 }
 
+static std::vector<PhdrEntry *> getAllPtLoads(ArrayRef<PhdrEntry *> V) {
+  std::vector<PhdrEntry *> Ret = V.vec();
+  llvm::erase_if(Ret, [](PhdrEntry *E) { return E->p_type != PT_LOAD; });
+  return Ret;
+}
+
+static std::vector<PhdrEntry *> getExecLoads(ArrayRef<PhdrEntry *> V) {
+  std::vector<PhdrEntry *> Ret;
+  for (PhdrEntry *Load : getAllPtLoads(V))
+    if (Load->p_flags & PF_X)
+      Ret.push_back(Load);
+  return Ret;
+}
+
 // Assign file offsets to output sections.
 template <class ELFT> void Writer<ELFT>::assignFileOffsets() {
   uint64_t Off = 0;
   Off = setOffset(Out::ElfHeader, Off);
   Off = setOffset(Out::ProgramHeaders, Off);
 
-  for (OutputSectionCommand *Cmd : OutputSectionCommands)
+  std::vector<PhdrEntry *> ExecLoads = getExecLoads(Phdrs);
+  for (OutputSectionCommand *Cmd : OutputSectionCommands) {
     Off = setOffset(Cmd->Sec, Off);
 
+    if (Script->Opt.HasSections)
+      continue;
+
+    // If no linker script is involved and allocatable section is the last in
+    // executable segment, that means we want to ensure segment contains only
+    // valid instructions and hence we align next section's offset to avoid
+    // loading of non-allocatable content. We will fill gap with trap op codes.
+    if (!ExecLoads.empty())
+      if (Cmd->Sec == ExecLoads.back()->Last)
+        Off = alignTo(Off, Target->PageSize);
+  }
+
   SectionHeaderOff = alignTo(Off, Config->Wordsize);
   FileSize =
       SectionHeaderOff + (OutputSectionCommands.size() + 1) * sizeof(Elf_Shdr);
 }
 
 // Finalize the program headers. We call this function after we assign
 // file offsets and VAs to all sections.
 template <class ELFT> void Writer<ELFT>::setPhdrs() {
-  for (PhdrEntry &P : Phdrs) {
-    OutputSection *First = P.First;
-    OutputSection *Last = P.Last;
+  for (PhdrEntry *P : Phdrs) {
+    OutputSection *First = P->First;
+    OutputSection *Last = P->Last;
     if (First) {
-      P.p_filesz = Last->Offset - First->Offset;
+      P->p_filesz = Last->Offset - First->Offset;
       if (Last->Type != SHT_NOBITS)
-        P.p_filesz += Last->Size;
-      P.p_memsz = Last->Addr + Last->Size - First->Addr;
-      P.p_offset = First->Offset;
-      P.p_vaddr = First->Addr;
-      if (!P.HasLMA)
-        P.p_paddr = First->getLMA();
-    }
-    if (P.p_type == PT_LOAD)
-      P.p_align = Config->MaxPageSize;
-    else if (P.p_type == PT_GNU_RELRO) {
-      P.p_align = 1;
+        P->p_filesz += Last->Size;
+      P->p_memsz = Last->Addr + Last->Size - First->Addr;
+      P->p_offset = First->Offset;
+      P->p_vaddr = First->Addr;
+      if (!P->HasLMA)
+        P->p_paddr = First->getLMA();
+    }
+    if (P->p_type == PT_LOAD)
+      P->p_align = Config->MaxPageSize;
+    else if (P->p_type == PT_GNU_RELRO) {
+      P->p_align = 1;
       // The glibc dynamic loader rounds the size down, so we need to round up
       // to protect the last page. This is a no-op on FreeBSD which always
       // rounds up.
-      P.p_memsz = alignTo(P.p_memsz, Target->PageSize);
+      P->p_memsz = alignTo(P->p_memsz, Target->PageSize);
     }
 
     // The TLS pointer goes after PT_TLS. At least glibc will align it,
     // so round up the size to make sure the offsets are correct.
-    if (P.p_type == PT_TLS) {
-      Out::TlsPhdr = &P;
-      if (P.p_memsz)
-        P.p_memsz = alignTo(P.p_memsz, P.p_align);
+    if (P->p_type == PT_TLS) {
+      Out::TlsPhdr = P;
+      if (P->p_memsz)
+        P->p_memsz = alignTo(P->p_memsz, P->p_align);
     }
   }
 }
 
 // The entry point address is chosen in the following ways.
 //
 // 1. the '-e' entry command-line option;
 // 2. the ENTRY(symbol) command in a linker control script;

 // symbol values that depend on section address and size.
 template <class ELFT> void Writer<ELFT>::fixPredefinedSymbols() {
   // _etext is the first location after the last read-only loadable segment.
   // _edata is the first location after the last read-write loadable segment.
   // _end is the first location after the uninitialized data region.
   PhdrEntry *Last = nullptr;
   PhdrEntry *LastRO = nullptr;
   PhdrEntry *LastRW = nullptr;
-  for (PhdrEntry &P : Phdrs) {
-    if (P.p_type != PT_LOAD)
+  for (PhdrEntry *P : Phdrs) {
+    if (P->p_type != PT_LOAD)
       continue;
-    Last = &P;
-    if (P.p_flags & PF_W)
-      LastRW = &P;
+    Last = P;
+    if (P->p_flags & PF_W)
+      LastRW = P;
     else
-      LastRO = &P;
+      LastRO = P;
   }
 
   auto Set = [](DefinedRegular *S, OutputSection *Sec, uint64_t Value) {
     if (S) {
       S->Section = Sec;
       S->Value = Value;
     }
   };
template <class ELFT> void Writer<ELFT>::writeHeader() {
 
   if (!Config->Relocatable) {
     EHdr->e_phoff = sizeof(Elf_Ehdr);
     EHdr->e_phentsize = sizeof(Elf_Phdr);
   }
 
   // Write the program header table.
   auto *HBuf = reinterpret_cast<Elf_Phdr *>(Buf + EHdr->e_phoff);
-  for (PhdrEntry &P : Phdrs) {
-    HBuf->p_type = P.p_type;
-    HBuf->p_flags = P.p_flags;
-    HBuf->p_offset = P.p_offset;
-    HBuf->p_vaddr = P.p_vaddr;
-    HBuf->p_paddr = P.p_paddr;
-    HBuf->p_filesz = P.p_filesz;
-    HBuf->p_memsz = P.p_memsz;
-    HBuf->p_align = P.p_align;
+  for (PhdrEntry *P : Phdrs) {
+    HBuf->p_type = P->p_type;
+    HBuf->p_flags = P->p_flags;
+    HBuf->p_offset = P->p_offset;
+    HBuf->p_vaddr = P->p_vaddr;
+    HBuf->p_paddr = P->p_paddr;
+    HBuf->p_filesz = P->p_filesz;
+    HBuf->p_memsz = P->p_memsz;
+    HBuf->p_align = P->p_align;
     ++HBuf;
   }
 
   // Write the section header table. Note that the first table entry is null.
   auto *SHdrs = reinterpret_cast<Elf_Shdr *>(Buf + EHdr->e_shoff);
   for (OutputSectionCommand *Cmd : OutputSectionCommands)
     Cmd->Sec->writeHeaderTo<ELFT>(++SHdrs);
 }
template <class ELFT> void Writer<ELFT>::writeSectionsBinary() {
   uint8_t *Buf = Buffer->getBufferStart();
   for (OutputSectionCommand *Cmd : OutputSectionCommands) {
     OutputSection *Sec = Cmd->Sec;
     if (Sec->Flags & SHF_ALLOC)
       Cmd->writeTo<ELFT>(Buf + Sec->Offset);
   }
 }
 
+static void fillPage(uint8_t *Buf, uint64_t Offset, uint32_t Filler) {
+  uint64_t Begin = alignDown(Offset, Target->PageSize);
+  uint64_t End = alignTo(Offset, Target->PageSize);
+  fill(Buf + Begin, End - Begin, Filler);
+}
+
+template <class ELFT> void Writer<ELFT>::writeTrapInstr() {
+  // FIXME: do the same for case when sections present.
+  if (Script->Opt.HasSections)
+    return;
+
+  uint8_t *Buf = Buffer->getBufferStart();
+  for (PhdrEntry *Load : getExecLoads(Phdrs)) {
+    // We only fill the first and the last page of the segment because the
+    // middle part will be overwritten by output sections.
+    fillPage(Buf, Load->p_offset, Target->TrapInstr);
+    fillPage(Buf, Load->p_offset + Load->p_filesz, Target->TrapInstr);
+  }
+
+  // Round up the file size of the last segment to the page boundary if it is
+  // an executable segment to ensure that other other tools don't accidentally
+  // trim the instruction padding (e.g. when stripping the file).
+  std::vector<PhdrEntry *> V = getAllPtLoads(Phdrs);
+  PhdrEntry *Last = V.empty() ? nullptr : V.back();
+  if (Last && (Last->p_flags & PF_X))
+    Last->p_filesz = alignTo(Last->p_filesz, Target->PageSize);
+}
+
 // Write section contents to a mmap'ed file.
 template <class ELFT> void Writer<ELFT>::writeSections() {
   uint8_t *Buf = Buffer->getBufferStart();
 
   // PPC64 needs to process relocations in the .opd section
   // before processing relocations in code-containing sections.
   if (auto *OpdCmd = findSectionCommand(".opd")) {
     Out::Opd = OpdCmd->Sec;

test/ELF/avoid-empty-program-headers.s

 // CHECK-NEXT:     ]
 // CHECK-NEXT:     Alignment: 4096
 // CHECK-NEXT:   }
 // CHECK-NEXT:   ProgramHeader {
 // CHECK-NEXT:     Type: PT_LOAD (0x1)
 // CHECK-NEXT:     Offset: 0x1000
 // CHECK-NEXT:     VirtualAddress: 0x201000
 // CHECK-NEXT:     PhysicalAddress: 0x201000
-// CHECK-NEXT:     FileSize: 1
+// CHECK-NEXT:     FileSize: 4096
 // CHECK-NEXT:     MemSize: 1
 // CHECK-NEXT:     Flags [ (0x5)
 // CHECK-NEXT:       PF_R (0x4)
 // CHECK-NEXT:       PF_X (0x1)
 // CHECK-NEXT:     ]
 // CHECK-NEXT:     Alignment: 4096
 // CHECK-NEXT:   }
 // CHECK-NEXT:   ProgramHeader {
 // CHECK-NEXT:     Type: PT_TLS (0x7)
-// CHECK-NEXT:     Offset: 0x1001
+// CHECK-NEXT:     Offset: 0x2000
 // CHECK-NEXT:     VirtualAddress: 0x201001
 // CHECK-NEXT:     PhysicalAddress: 0x201001
 // CHECK-NEXT:     FileSize: 0
 // CHECK-NEXT:     MemSize: 4
 // CHECK-NEXT:     Flags [ (0x4)
 // CHECK-NEXT:       PF_R (0x4)
 // CHECK-NEXT:     ]
 // CHECK-NEXT:     Alignment: 1

test/ELF/basic-aarch64.s

 # CHECK-NEXT:     ABIVersion: 0
 # CHECK-NEXT:     Unused: (00 00 00 00 00 00 00)
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Type: Executable (0x2)
 # CHECK-NEXT:   Machine: EM_AARCH64 (0xB7)
 # CHECK-NEXT:   Version: 1
 # CHECK-NEXT:   Entry: [[ENTRY:0x[0-9A-F]+]]
 # CHECK-NEXT:   ProgramHeaderOffset: 0x40
-# CHECK-NEXT:   SectionHeaderOffset: 0x10098
+# CHECK-NEXT:   SectionHeaderOffset: 0x11088
 # CHECK-NEXT:   Flags [ (0x0)
 # CHECK-NEXT:   ]
 # CHECK-NEXT:   HeaderSize: 64
 # CHECK-NEXT:   ProgramHeaderEntrySize: 56
 # CHECK-NEXT:   ProgramHeaderCount: 4
 # CHECK-NEXT:   SectionHeaderEntrySize: 64
 # CHECK-NEXT:   SectionHeaderCount: 6
 # CHECK-NEXT:   StringTableSectionIndex: 4

 # CHECK-NEXT:     Index: 2
 # CHECK-NEXT:     Name: .comment
 # CHECK-NEXT:     Type: SHT_PROGBITS (0x1)
 # CHECK-NEXT:     Flags [ (0x30)
 # CHECK-NEXT:       SHF_MERGE (0x10)
 # CHECK-NEXT:       SHF_STRINGS (0x20)
 # CHECK-NEXT:     ]
 # CHECK-NEXT:     Address: 0x0
-# CHECK-NEXT:     Offset: 0x1000C
+# CHECK-NEXT:     Offset: 0x11000
 # CHECK-NEXT:     Size: 8
 # CHECK-NEXT:     Link: 0
 # CHECK-NEXT:     Info: 0
 # CHECK-NEXT:     AddressAlignment: 1
 # CHECK-NEXT:     EntrySize: 0
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Section {
 # CHECK-NEXT:     Index: 3
 # CHECK-NEXT:     Name: .symtab
 # CHECK-NEXT:     Type: SHT_SYMTAB (0x2)
 # CHECK-NEXT:     Flags [ (0x0)
 # CHECK-NEXT:     ]
 # CHECK-NEXT:     Address: 0x0
-# CHECK-NEXT:     Offset: 0x10018
+# CHECK-NEXT:     Offset: 0x11008
 # CHECK-NEXT:     Size: 72
 # CHECK-NEXT:     Link: 5
 # CHECK-NEXT:     Info: 2
 # CHECK-NEXT:     AddressAlignment: 8
 # CHECK-NEXT:     EntrySize: 24
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Section {
 # CHECK-NEXT:     Index: 4
 # CHECK-NEXT:     Name: .shstrtab
 # CHECK-NEXT:     Type: SHT_STRTAB (0x3)
 # CHECK-NEXT:     Flags [ (0x0)
 # CHECK-NEXT:     ]
 # CHECK-NEXT:     Address: 0x0
-# CHECK-NEXT:     Offset: 0x10060
+# CHECK-NEXT:     Offset: 0x11050
 # CHECK-NEXT:     Size: 42
 # CHECK-NEXT:     Link: 0
 # CHECK-NEXT:     Info: 0
 # CHECK-NEXT:     AddressAlignment: 1
 # CHECK-NEXT:     EntrySize: 0
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Section {
 # CHECK-NEXT:     Index: 5
 # CHECK-NEXT:     Name: .strtab
 # CHECK-NEXT:     Type: SHT_STRTAB (0x3)
 # CHECK-NEXT:     Flags [ (0x0)
 # CHECK-NEXT:     ]
 # CHECK-NEXT:     Address: 0x0
-# CHECK-NEXT:     Offset: 0x1008A
+# CHECK-NEXT:     Offset: 0x1107A
 # CHECK-NEXT:     Size: 13
 # CHECK-NEXT:     Link: 0
 # CHECK-NEXT:     Info: 0
 # CHECK-NEXT:     AddressAlignment: 1
 # CHECK-NEXT:     EntrySize: 0
 # CHECK-NEXT:   }
 # CHECK-NEXT: ]
 # CHECK-NEXT: Symbols [

 # CHECK-NEXT:     ]
 # CHECK-NEXT:     Alignment: 65536
 # CHECK-NEXT:   }
 # CHECK-NEXT:   ProgramHeader {
 # CHECK-NEXT:     Type: PT_LOAD (0x1)
 # CHECK-NEXT:     Offset: 0x1000
 # CHECK-NEXT:     VirtualAddress: 0x20000
 # CHECK-NEXT:     PhysicalAddress: 0x20000
-# CHECK-NEXT:     FileSize: 12
+# CHECK-NEXT:     FileSize: 4096
 # CHECK-NEXT:     MemSize: 12
 # CHECK-NEXT:     Flags [ (0x5)
 # CHECK-NEXT:       PF_R (0x4)
 # CHECK-NEXT:       PF_X (0x1)
 # CHECK-NEXT:     ]
 # CHECK-NEXT:     Alignment: 65536
 # CHECK-NEXT:   }
 # CHECK-NEXT:   ProgramHeader {

test/ELF/basic-sparcv9.s

 # CHECK-NEXT:     ABIVersion: 0
 # CHECK-NEXT:     Unused: (00 00 00 00 00 00 00)
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Type: Executable (0x2)
 # CHECK-NEXT:   Machine: EM_SPARCV9 (0x2B)
 # CHECK-NEXT:   Version: 1
 # CHECK-NEXT:   Entry: [[ENTRY:0x[0-9A-F]+]]
 # CHECK-NEXT:   ProgramHeaderOffset: 0x40
-# CHECK-NEXT:   SectionHeaderOffset: 0x100080
+# CHECK-NEXT:   SectionHeaderOffset: 0x102070
 # CHECK-NEXT:   Flags [ (0x0)
 # CHECK-NEXT:   ]
 # CHECK-NEXT:   HeaderSize: 64
 # CHECK-NEXT:   ProgramHeaderEntrySize: 56
 # CHECK-NEXT:   ProgramHeaderCount: 4
 # CHECK-NEXT:   SectionHeaderEntrySize: 64
 # CHECK-NEXT:   SectionHeaderCount: 6
 # CHECK-NEXT:   StringTableSectionIndex: 4

 # CHECK-NEXT:     Index: 2
 # CHECK-NEXT:     Name: .comment
 # CHECK-NEXT:     Type: SHT_PROGBITS (0x1)
 # CHECK-NEXT:     Flags [ (0x30)
 # CHECK-NEXT:       SHF_MERGE (0x10)
 # CHECK-NEXT:       SHF_STRINGS (0x20)
 # CHECK-NEXT:     ]
 # CHECK-NEXT:     Address: 0x0
-# CHECK-NEXT:     Offset: 0x10000C
+# CHECK-NEXT:     Offset: 0x102000
 # CHECK-NEXT:     Size: 8
 # CHECK-NEXT:     Link: 0
 # CHECK-NEXT:     Info: 0
 # CHECK-NEXT:     AddressAlignment: 1
 # CHECK-NEXT:     EntrySize: 0
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Section {
 # CHECK-NEXT:     Index: 3
 # CHECK-NEXT:     Name: .symtab
 # CHECK-NEXT:     Type: SHT_SYMTAB (0x2)
 # CHECK-NEXT:     Flags [ (0x0)
 # CHECK-NEXT:     ]
 # CHECK-NEXT:     Address: 0x0
-# CHECK-NEXT:     Offset: 0x100018
+# CHECK-NEXT:     Offset: 0x102008
 # CHECK-NEXT:     Size: 48
 # CHECK-NEXT:     Link: 5
 # CHECK-NEXT:     Info: 1
 # CHECK-NEXT:     AddressAlignment: 8
 # CHECK-NEXT:     EntrySize: 24
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Section {
 # CHECK-NEXT:     Index: 4
 # CHECK-NEXT:     Name: .shstrtab
 # CHECK-NEXT:     Type: SHT_STRTAB (0x3)
 # CHECK-NEXT:     Flags [ (0x0)
 # CHECK-NEXT:     ]
 # CHECK-NEXT:     Address: 0x0
-# CHECK-NEXT:     Offset: 0x100048
+# CHECK-NEXT:     Offset: 0x102038
 # CHECK-NEXT:     Size: 42
 # CHECK-NEXT:     Link: 0
 # CHECK-NEXT:     Info: 0
 # CHECK-NEXT:     AddressAlignment: 1
 # CHECK-NEXT:     EntrySize: 0
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Section {
 # CHECK-NEXT:     Index: 5
 # CHECK-NEXT:     Name: .strtab
 # CHECK-NEXT:     Type: SHT_STRTAB (0x3)
 # CHECK-NEXT:     Flags [ (0x0)
 # CHECK-NEXT:     ]
 # CHECK-NEXT:     Address: 0x0
-# CHECK-NEXT:     Offset: 0x100072
+# CHECK-NEXT:     Offset: 0x102062
 # CHECK-NEXT:     Size: 8
 # CHECK-NEXT:     Link: 0
 # CHECK-NEXT:     Info: 0
 # CHECK-NEXT:     AddressAlignment: 1
 # CHECK-NEXT:     EntrySize: 0
 # CHECK-NEXT:   }
 # CHECK-NEXT: ]
 # CHECK-NEXT: Symbols [

 # CHECK-NEXT:     ]
 # CHECK-NEXT:     Alignment: 1048576
 # CHECK-NEXT:   }
 # CHECK-NEXT:   ProgramHeader {
 # CHECK-NEXT:     Type: PT_LOAD (0x1)
 # CHECK-NEXT:     Offset: 0x100000
 # CHECK-NEXT:     VirtualAddress: 0x200000
 # CHECK-NEXT:     PhysicalAddress: 0x200000
-# CHECK-NEXT:     FileSize: 12
+# CHECK-NEXT:     FileSize: 8192
 # CHECK-NEXT:     MemSize: 12
 # CHECK-NEXT:     Flags [ (0x5)
 # CHECK-NEXT:       PF_R (0x4)
 # CHECK-NEXT:       PF_X (0x1)
 # CHECK-NEXT:     ]
 # CHECK-NEXT:     Alignment: 1048576
 # CHECK-NEXT:   }
 # CHECK-NEXT:   ProgramHeader {

test/ELF/basic.s

 # CHECK-NEXT:     ABIVersion: 0
 # CHECK-NEXT:     Unused: (00 00 00 00 00 00 00)
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Type: Executable (0x2)
 # CHECK-NEXT:   Machine: EM_X86_64 (0x3E)
 # CHECK-NEXT:   Version: 1
 # CHECK-NEXT:   Entry: [[ENTRY:0x[0-9A-F]+]]
 # CHECK-NEXT:   ProgramHeaderOffset: 0x40
-# CHECK-NEXT:   SectionHeaderOffset: 0x1080
+# CHECK-NEXT:   SectionHeaderOffset: 0x2070
 # CHECK-NEXT:   Flags [ (0x0)
 # CHECK-NEXT:   ]
 # CHECK-NEXT:   HeaderSize: 64
 # CHECK-NEXT:   ProgramHeaderEntrySize: 56
 # CHECK-NEXT:   ProgramHeaderCount: 4
 # CHECK-NEXT:   SectionHeaderEntrySize: 64
 # CHECK-NEXT:   SectionHeaderCount: 6
 # CHECK-NEXT:   StringTableSectionIndex: 4

 # CHECK-NEXT:     Index: 2
 # CHECK-NEXT:     Name: .comment
 # CHECK-NEXT:     Type: SHT_PROGBITS (0x1)
 # CHECK-NEXT:     Flags [ (0x30)
 # CHECK-NEXT:       SHF_MERGE (0x10)
 # CHECK-NEXT:       SHF_STRINGS (0x20)
 # CHECK-NEXT:     ]
 # CHECK-NEXT:     Address: 0x0
-# CHECK-NEXT:     Offset: 0x1010
+# CHECK-NEXT:     Offset: 0x2000
 # CHECK-NEXT:     Size: 8
 # CHECK-NEXT:     Link: 0
 # CHECK-NEXT:     Info: 0
 # CHECK-NEXT:     AddressAlignment: 1
 # CHECK-NEXT:     EntrySize: 0
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Section {
 # CHECK-NEXT:     Index: 3
 # CHECK-NEXT:     Name: .symtab
 # CHECK-NEXT:     Type: SHT_SYMTAB (0x2)
 # CHECK-NEXT:     Flags [ (0x0)
 # CHECK-NEXT:     ]
 # CHECK-NEXT:     Address: 0x0
-# CHECK-NEXT:     Offset: 0x1018
+# CHECK-NEXT:     Offset: 0x2008
 # CHECK-NEXT:     Size: 48
 # CHECK-NEXT:     Link: 5
 # CHECK-NEXT:     Info: 1
 # CHECK-NEXT:     AddressAlignment: 8
 # CHECK-NEXT:     EntrySize: 24
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Section {
 # CHECK-NEXT:     Index: 4
 # CHECK-NEXT:     Name: .shstrtab
 # CHECK-NEXT:     Type: SHT_STRTAB (0x3)
 # CHECK-NEXT:     Flags [ (0x0)
 # CHECK-NEXT:     ]
 # CHECK-NEXT:     Address: 0x0
-# CHECK-NEXT:     Offset: 0x1048
+# CHECK-NEXT:     Offset: 0x2038
 # CHECK-NEXT:     Size: 42
 # CHECK-NEXT:     Link: 0
 # CHECK-NEXT:     Info: 0
 # CHECK-NEXT:     AddressAlignment: 1
 # CHECK-NEXT:     EntrySize: 0
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Section {
 # CHECK-NEXT:     Index: 5
 # CHECK-NEXT:     Name: .strtab
 # CHECK-NEXT:     Type: SHT_STRTAB (0x3)
 # CHECK-NEXT:     Flags [ (0x0)
 # CHECK-NEXT:     ]
 # CHECK-NEXT:     Address: 0x0
-# CHECK-NEXT:     Offset: 0x1072
+# CHECK-NEXT:     Offset: 0x2062
 # CHECK-NEXT:     Size: 8
 # CHECK-NEXT:     Link: 0
 # CHECK-NEXT:     Info: 0
 # CHECK-NEXT:     AddressAlignment: 1
 # CHECK-NEXT:     EntrySize: 0
 # CHECK-NEXT:   }
 # CHECK-NEXT: ]
 # CHECK-NEXT: Symbols [

 # CHECK-NEXT:     ]
 # CHECK-NEXT:     Alignment: 4096
 # CHECK-NEXT:   }
 # CHECK-NEXT:   ProgramHeader {
 # CHECK-NEXT:     Type: PT_LOAD (0x1)
 # CHECK-NEXT:     Offset: 0x1000
 # CHECK-NEXT:     VirtualAddress: 0x201000
 # CHECK-NEXT:     PhysicalAddress: 0x201000
-# CHECK-NEXT:     FileSize: 16
+# CHECK-NEXT:     FileSize: 4096
 # CHECK-NEXT:     MemSize: 16
 # CHECK-NEXT:     Flags [ (0x5)
 # CHECK-NEXT:       PF_R (0x4)
 # CHECK-NEXT:       PF_X (0x1)
 # CHECK-NEXT:     ]
 # CHECK-NEXT:     Alignment: 4096
 # CHECK-NEXT:   }
 # CHECK-NEXT:   ProgramHeader {

test/ELF/basic32.s

 # CHECK-NEXT:     ABIVersion: 0
 # CHECK-NEXT:     Unused: (00 00 00 00 00 00 00)
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Type: Executable (0x2)
 # CHECK-NEXT:   Machine: EM_386 (0x3)
 # CHECK-NEXT:   Version: 1
 # CHECK-NEXT:   Entry: 0x11000
 # CHECK-NEXT:   ProgramHeaderOffset: 0x34
-# CHECK-NEXT:   SectionHeaderOffset: 0x1068
+# CHECK-NEXT:   SectionHeaderOffset: 0x205C
 # CHECK-NEXT:   Flags [ (0x0)
 # CHECK-NEXT:   ]
 # CHECK-NEXT:   HeaderSize: 52
 # CHECK-NEXT:   ProgramHeaderEntrySize: 32
 # CHECK-NEXT:   ProgramHeaderCount: 4
 # CHECK-NEXT:   SectionHeaderEntrySize: 40
 # CHECK-NEXT:   SectionHeaderCount: 6
 # CHECK-NEXT:   StringTableSectionIndex: 4

 # CHECK-NEXT:     Index: 2
 # CHECK-NEXT:     Name: .comment
 # CHECK-NEXT:     Type: SHT_PROGBITS (0x1)
 # CHECK-NEXT:     Flags [ (0x30)
 # CHECK-NEXT:       SHF_MERGE (0x10)
 # CHECK-NEXT:       SHF_STRINGS (0x20)
 # CHECK-NEXT:     ]
 # CHECK-NEXT:     Address: 0x0
-# CHECK-NEXT:     Offset: 0x100C
+# CHECK-NEXT:     Offset: 0x2000
 # CHECK-NEXT:     Size: 8
 # CHECK-NEXT:     Link: 0
 # CHECK-NEXT:     Info: 0
 # CHECK-NEXT:     AddressAlignment: 1
 # CHECK-NEXT:     EntrySize: 0
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Section {
 # CHECK-NEXT:     Index: 3
 # CHECK-NEXT:     Name: .symtab
 # CHECK-NEXT:     Type: SHT_SYMTAB
 # CHECK-NEXT:     Flags [
 # CHECK-NEXT:     ]
 # CHECK-NEXT:     Address: 0x0
-# CHECK-NEXT:     Offset: 0x1014
+# CHECK-NEXT:     Offset: 0x2008
 # CHECK-NEXT:     Size: 32
 # CHECK-NEXT:     Link: 5
 # CHECK-NEXT:     Info: 1
 # CHECK-NEXT:     AddressAlignment: 4
 # CHECK-NEXT:     EntrySize: 16
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Section {
 # CHECK-NEXT:     Index: 4
 # CHECK-NEXT:     Name: .shstrtab
 # CHECK-NEXT:     Type: SHT_STRTAB (0x3)
 # CHECK-NEXT:     Flags [ (0x0)
 # CHECK-NEXT:     ]
 # CHECK-NEXT:     Address: 0x0
-# CHECK-NEXT:     Offset: 0x1034
+# CHECK-NEXT:     Offset: 0x2028
 # CHECK-NEXT:     Size: 42
 # CHECK-NEXT:     Link: 0
 # CHECK-NEXT:     Info: 0
 # CHECK-NEXT:     AddressAlignment: 1
 # CHECK-NEXT:     EntrySize: 0
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Section {
 # CHECK-NEXT:     Index: 5
 # CHECK-NEXT:     Name: .strtab
 # CHECK-NEXT:     Type: SHT_STRTAB (0x3)
 # CHECK-NEXT:     Flags [ (0x0)
 # CHECK-NEXT:     ]
 # CHECK-NEXT:     Address: 0x0
-# CHECK-NEXT:     Offset: 0x105E
+# CHECK-NEXT:     Offset: 0x2052
 # CHECK-NEXT:     Size: 8
 # CHECK-NEXT:     Link: 0
 # CHECK-NEXT:     Info: 0
 # CHECK-NEXT:     AddressAlignment: 1
 # CHECK-NEXT:     EntrySize: 0
 # CHECK-NEXT:   }
 # CHECK-NEXT: ]
 # CHECK-NEXT: ProgramHeaders [

 # CHECK-NEXT:     ]
 # CHECK-NEXT:     Alignment: 4096
 # CHECK-NEXT:   }
 # CHECK-NEXT:   ProgramHeader {
 # CHECK-NEXT:     Type: PT_LOAD (0x1)
 # CHECK-NEXT:     Offset: 0x1000
 # CHECK-NEXT:     VirtualAddress: 0x11000
 # CHECK-NEXT:     PhysicalAddress: 0x11000
-# CHECK-NEXT:     FileSize: 12
+# CHECK-NEXT:     FileSize: 4096
 # CHECK-NEXT:     MemSize: 12
 # CHECK-NEXT:     Flags [ (0x5)
 # CHECK-NEXT:       PF_R (0x4)
 # CHECK-NEXT:       PF_X (0x1)
 # CHECK-NEXT:     ]
 # CHECK-NEXT:     Alignment: 4096
 # CHECK-NEXT:   }
 # CHECK-NEXT:   ProgramHeader {

test/ELF/build-id.s

_start:
   nop
 
 .section .note.test, "a", @note
    .quad 42
 
 # DEFAULT:      Contents of section .note.test:
 # DEFAULT:      Contents of section .note.gnu.build-id:
 # DEFAULT-NEXT: 04000000 08000000 03000000 474e5500  ............GNU.
-# DEFAULT-NEXT: fd36edb1 f6ff02af
+# DEFAULT-NEXT: b0148597 ba5eb7e9
 
 # MD5:      Contents of section .note.gnu.build-id:
 # MD5-NEXT: 04000000 10000000 03000000 474e5500  ............GNU.
 # MD5-NEXT: fc
 
 # SHA1:      Contents of section .note.gnu.build-id:
 # SHA1-NEXT: 04000000 14000000 03000000 474e5500  ............GNU.
-# SHA1-NEXT: 55b1eedb 03b588e1 09987d1d e9a79be7
+# SHA1-NEXT: 2f716666 fe3668fe 370a02a1 579c3eb2
 
 # UUID:      Contents of section .note.gnu.build-id:
 # UUID-NEXT: 04000000 10000000 03000000 474e5500  ............GNU.
 
 # HEX:      Contents of section .note.gnu.build-id:
 # HEX-NEXT: 04000000 04000000 03000000 474e5500  ............GNU.
 # HEX-NEXT: 12345678
 
 # NONE-NOT: Contents of section .note.gnu.build-id:

test/ELF/image-base.s

 # CHECK-NEXT:     ]
 # CHECK-NEXT:     Alignment: 4096
 # CHECK-NEXT:   }
 # CHECK-NEXT:   ProgramHeader {
 # CHECK-NEXT:     Type: PT_LOAD (0x1)
 # CHECK-NEXT:     Offset: 0x1000
 # CHECK-NEXT:     VirtualAddress: 0x1001000
 # CHECK-NEXT:     PhysicalAddress: 0x1001000
-# CHECK-NEXT:     FileSize: 1
+# CHECK-NEXT:     FileSize: 4096
 # CHECK-NEXT:     MemSize: 1
 # CHECK-NEXT:     Flags [ (0x5)
 # CHECK-NEXT:       PF_R (0x4)
 # CHECK-NEXT:       PF_X (0x1)
 # CHECK-NEXT:     ]
 # CHECK-NEXT:     Alignment: 4096
 # CHECK-NEXT:   }
 # CHECK-NEXT:   ProgramHeader {

test/ELF/relocatable.s

 # CHECKEXE-NEXT:      ABIVersion: 0
 # CHECKEXE-NEXT:      Unused: (00 00 00 00 00 00 00)
 # CHECKEXE-NEXT:    }
 # CHECKEXE-NEXT:    Type: Executable
 # CHECKEXE-NEXT:    Machine: EM_X86_64
 # CHECKEXE-NEXT:    Version: 1
 # CHECKEXE-NEXT:    Entry: 0x201000
 # CHECKEXE-NEXT:    ProgramHeaderOffset: 0x40
-# CHECKEXE-NEXT:    SectionHeaderOffset: 0x11F8
+# CHECKEXE-NEXT:    SectionHeaderOffset: 0x21A0
 # CHECKEXE-NEXT:    Flags [
 # CHECKEXE-NEXT:    ]
 # CHECKEXE-NEXT:    HeaderSize: 64
 # CHECKEXE-NEXT:    ProgramHeaderEntrySize: 56
 # CHECKEXE-NEXT:    ProgramHeaderCount: 5
 # CHECKEXE-NEXT:    SectionHeaderEntrySize: 64
 # CHECKEXE-NEXT:    SectionHeaderCount: 7
 # CHECKEXE-NEXT:    StringTableSectionIndex: 5