Index: ELF/OutputSections.h =================================================================== --- ELF/OutputSections.h +++ ELF/OutputSections.h @@ -98,8 +98,6 @@ // until Writer is initialized. struct Out { static uint8_t First; - static OutputSection *Bss; - static OutputSection *BssRelRo; static OutputSection *Opd; static uint8_t *OpdBuf; static PhdrEntry *TlsPhdr; Index: ELF/OutputSections.cpp =================================================================== --- ELF/OutputSections.cpp +++ ELF/OutputSections.cpp @@ -31,8 +31,6 @@ using namespace lld::elf; uint8_t Out::First; -OutputSection *Out::Bss; -OutputSection *Out::BssRelRo; OutputSection *Out::Opd; uint8_t *Out::OpdBuf; PhdrEntry *Out::TlsPhdr; Index: ELF/Relocations.cpp =================================================================== --- ELF/Relocations.cpp +++ ELF/Relocations.cpp @@ -479,23 +479,19 @@ // See if this symbol is in a read-only segment. If so, preserve the symbol's // memory protection by reserving space in the .bss.rel.ro section. bool IsReadOnly = isReadOnly(SS); - OutputSection *OSec = IsReadOnly ? Out::BssRelRo : Out::Bss; - - // Create a SyntheticSection in Out to hold the .bss and the Copy Reloc. - auto *ISec = - make>(IsReadOnly, SS->getAlignment(), SymSize); - OSec->addSection(ISec); + BssRelSection *RelSec = IsReadOnly ? In::BssRelRo : In::Bss; + size_t Off = RelSec->addCopyRelocation(SS->getAlignment(), SymSize); // Look through the DSO's dynamic symbol table for aliases and create a // dynamic symbol for each one. This causes the copy relocation to correctly // interpose any aliases. for (SharedSymbol *Sym : getSymbolsAt(SS)) { Sym->NeedsCopy = true; - Sym->Section = ISec; + Sym->CopyRelSec = {RelSec, Off}; Sym->symbol()->IsUsedInRegularObj = true; } - In::RelaDyn->addReloc({Target->CopyRel, ISec, 0, false, SS, 0}); + In::RelaDyn->addReloc({Target->CopyRel, RelSec, Off, false, SS, 0}); } template Index: ELF/Symbols.h =================================================================== --- ELF/Symbols.h +++ ELF/Symbols.h @@ -275,8 +275,11 @@ // This field is a pointer to the symbol's version definition. const void *Verdef; - // Section is significant only when NeedsCopy is true. - InputSection *Section = nullptr; + // CopyRelSec is significant only when NeedsCopy is true. + struct { + InputSection *Sec; + size_t Off; + } CopyRelSec; private: template const typename ELFT::Sym &getSym() const { Index: ELF/Symbols.cpp =================================================================== --- ELF/Symbols.cpp +++ ELF/Symbols.cpp @@ -103,7 +103,8 @@ case SymbolBody::SharedKind: { auto &SS = cast(Body); if (SS.NeedsCopy) - return SS.Section->OutSec->Addr + SS.Section->OutSecOff; + return SS.CopyRelSec.Sec->OutSec->Addr + SS.CopyRelSec.Sec->OutSecOff + + SS.CopyRelSec.Off; if (SS.NeedsPltAddr) return Body.getPltVA(); return 0; @@ -205,7 +206,7 @@ if (auto *S = dyn_cast(this)) { if (S->NeedsCopy) - return S->Section->OutSec; + return S->CopyRelSec.Sec->OutSec; return nullptr; } Index: ELF/SyntheticSections.h =================================================================== --- ELF/SyntheticSections.h +++ ELF/SyntheticSections.h @@ -147,14 +147,16 @@ uint8_t *HashBuf; }; -// For each copy relocation, we create an instance of this class to -// reserve space in .bss or .bss.rel.ro. -template class CopyRelSection final : public SyntheticSection { +// Section used for storing copy relocations. We create two sections now, +// .bss.rel.ro for RelRo case and .bss for regular case. +template class BssRelSection final : public SyntheticSection { typedef typename ELFT::uint uintX_t; public: - CopyRelSection(bool ReadOnly, uintX_t AddrAlign, size_t Size); + BssRelSection(bool RelRo); void writeTo(uint8_t *) override {} + bool empty() const override { return getSize() == 0; } + size_t addCopyRelocation(uintX_t AddrAlign, size_t Size); size_t getSize() const override { return Size; } size_t Size; }; @@ -765,6 +767,8 @@ template struct In { static InputSection *ARMAttributes; static BuildIdSection *BuildId; + static BssRelSection *Bss; + static BssRelSection *BssRelRo; static InputSection *Common; static DynamicSection *Dynamic; static StringTableSection *DynStrTab; @@ -794,6 +798,8 @@ }; template InputSection *In::ARMAttributes; +template BssRelSection *In::Bss; +template BssRelSection *In::BssRelRo; template BuildIdSection *In::BuildId; template InputSection *In::Common; template DynamicSection *In::Dynamic; Index: ELF/SyntheticSections.cpp =================================================================== --- ELF/SyntheticSections.cpp +++ ELF/SyntheticSections.cpp @@ -368,10 +368,17 @@ } template -CopyRelSection::CopyRelSection(bool ReadOnly, uintX_t AddrAlign, size_t S) - : SyntheticSection(SHF_ALLOC, SHT_NOBITS, AddrAlign, - ReadOnly ? ".bss.rel.ro" : ".bss"), - Size(S) {} +BssRelSection::BssRelSection(bool RelRo) + : SyntheticSection(SHF_ALLOC | SHF_WRITE, SHT_NOBITS, 0, + RelRo ? ".bss.rel.ro" : ".bss"), + Size(0) {} + +template +size_t BssRelSection::addCopyRelocation(uintX_t AddrAlign, size_t Size) { + OutSec->updateAlignment(AddrAlign); + this->Size = alignTo(this->Size, AddrAlign) + Size; + return this->Size - Size; +} template void BuildIdSection::writeBuildId(ArrayRef Buf) { @@ -2216,10 +2223,10 @@ template class elf::BuildIdSection; template class elf::BuildIdSection; -template class elf::CopyRelSection; -template class elf::CopyRelSection; -template class elf::CopyRelSection; -template class elf::CopyRelSection; +template class elf::BssRelSection; +template class elf::BssRelSection; +template class elf::BssRelSection; +template class elf::BssRelSection; template class elf::GotSection; template class elf::GotSection; Index: ELF/Writer.cpp =================================================================== --- ELF/Writer.cpp +++ ELF/Writer.cpp @@ -111,8 +111,8 @@ } for (StringRef V : - {".text.", ".rodata.", ".data.rel.ro.", ".data.", ".bss.", - ".init_array.", ".fini_array.", ".ctors.", ".dtors.", ".tbss.", + {".text.", ".rodata.", ".data.rel.ro.", ".data.", ".bss.rel.ro.", + ".bss.", ".init_array.", ".fini_array.", ".ctors.", ".dtors.", ".tbss.", ".gcc_except_table.", ".tdata.", ".ARM.exidx."}) { StringRef Prefix = V.drop_back(); if (Name.startswith(V) || Name == Prefix) @@ -309,10 +309,6 @@ auto Add = [](InputSectionBase *Sec) { InputSections.push_back(Sec); }; - // Create singleton output sections. - Out::Bss = make(".bss", SHT_NOBITS, SHF_ALLOC | SHF_WRITE); - Out::BssRelRo = - make(".bss.rel.ro", SHT_NOBITS, SHF_ALLOC | SHF_WRITE); In::DynStrTab = make>(".dynstr", true); In::Dynamic = make>(); In::RelaDyn = make>( @@ -350,6 +346,11 @@ Add(Common); } + In::Bss = make>(false /*RelRo*/); + Add(In::Bss); + In::BssRelRo = make>(true /*RelRo*/); + Add(In::BssRelRo); + // Add MIPS-specific sections. bool HasDynSymTab = !Symtab::X->getSharedFiles().empty() || Config->pic() || @@ -594,7 +595,7 @@ return true; if (In::Got && Sec == In::Got->OutSec) return true; - if (Sec == Out::BssRelRo) + if (Sec == In::BssRelRo->OutSec) return true; StringRef S = Sec->Name; @@ -1160,27 +1161,18 @@ // Dynamic section must be the last one in this list and dynamic // symbol table section (DynSymTab) must be the first one. finalizeSynthetic( - {In::DynSymTab, In::GnuHashTab, In::HashTab, - In::SymTab, In::ShStrTab, In::StrTab, - In::VerDef, In::DynStrTab, In::GdbIndex, - In::Got, In::MipsGot, In::IgotPlt, - In::GotPlt, In::RelaDyn, In::RelaIplt, - In::RelaPlt, In::Plt, In::Iplt, - In::Plt, In::EhFrameHdr, In::VerSym, - In::VerNeed, In::Dynamic}); + {In::DynSymTab, In::Bss, In::BssRelRo, + In::GnuHashTab, In::HashTab, In::SymTab, + In::ShStrTab, In::StrTab, In::VerDef, + In::DynStrTab, In::GdbIndex, In::Got, + In::MipsGot, In::IgotPlt, In::GotPlt, + In::RelaDyn, In::RelaIplt, In::RelaPlt, + In::Plt, In::Iplt, In::Plt, + In::EhFrameHdr, In::VerSym, In::VerNeed, + In::Dynamic}); } template void Writer::addPredefinedSections() { - // Add BSS sections. - auto Add = [=](OutputSection *Sec) { - if (!Sec->Sections.empty()) { - Sec->assignOffsets(); - OutputSections.push_back(Sec); - } - }; - Add(Out::Bss); - Add(Out::BssRelRo); - // ARM ABI requires .ARM.exidx to be terminated by some piece of data. // We have the terminater synthetic section class. Add that at the end. auto *OS = dyn_cast_or_null(findSection(".ARM.exidx"));