Index: lld/trunk/ELF/OutputSections.h =================================================================== --- lld/trunk/ELF/OutputSections.h +++ lld/trunk/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: lld/trunk/ELF/OutputSections.cpp =================================================================== --- lld/trunk/ELF/OutputSections.cpp +++ lld/trunk/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: lld/trunk/ELF/Relocations.cpp =================================================================== --- lld/trunk/ELF/Relocations.cpp +++ lld/trunk/ELF/Relocations.cpp @@ -479,23 +479,20 @@ // 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->symbol()->IsUsedInRegularObj = true; + replaceBody(Sym->symbol(), Sym->getName(), + /*IsLocal=*/false, Sym->StOther, Sym->Type, Off, + Sym->getSize(), RelSec, nullptr); } - In::RelaDyn->addReloc({Target->CopyRel, ISec, 0, false, SS, 0}); + In::RelaDyn->addReloc({Target->CopyRel, RelSec, Off, false, SS, 0}); } template @@ -535,14 +532,12 @@ if (Body.isObject()) { // Produce a copy relocation. auto *B = cast(&Body); - if (!B->NeedsCopy) { - if (Config->ZNocopyreloc) - error(S.getLocation(RelOff) + ": unresolvable relocation " + - toString(Type) + " against symbol '" + toString(*B) + - "'; recompile with -fPIC or remove '-z nocopyreloc'"); + if (Config->ZNocopyreloc) + error(S.getLocation(RelOff) + ": unresolvable relocation " + + toString(Type) + " against symbol '" + toString(*B) + + "'; recompile with -fPIC or remove '-z nocopyreloc'"); - addCopyRelSymbol(B); - } + addCopyRelSymbol(B); return Expr; } if (Body.isFunc()) { Index: lld/trunk/ELF/Symbols.h =================================================================== --- lld/trunk/ELF/Symbols.h +++ lld/trunk/ELF/Symbols.h @@ -102,10 +102,6 @@ const unsigned SymbolKind : 8; public: - // True if the linker has to generate a copy relocation. - // For SharedSymbol only. - unsigned NeedsCopy : 1; - // True the symbol should point to its PLT entry. // For SharedSymbol only. unsigned NeedsPltAddr : 1; @@ -270,9 +266,6 @@ // 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; - private: template const typename ELFT::Sym &getSym() const { return *(const typename ELFT::Sym *)ElfSym; Index: lld/trunk/ELF/Symbols.cpp =================================================================== --- lld/trunk/ELF/Symbols.cpp +++ lld/trunk/ELF/Symbols.cpp @@ -114,14 +114,10 @@ return 0; return In::Common->OutSec->Addr + In::Common->OutSecOff + cast(Body).Offset; - case SymbolBody::SharedKind: { - auto &SS = cast(Body); - if (SS.NeedsCopy) - return SS.Section->OutSec->Addr + SS.Section->OutSecOff; - if (SS.NeedsPltAddr) + case SymbolBody::SharedKind: + if (cast(Body).NeedsPltAddr) return Body.getPltVA(); return 0; - } case SymbolBody::UndefinedKind: return 0; case SymbolBody::LazyArchiveKind: @@ -134,7 +130,7 @@ SymbolBody::SymbolBody(Kind K, StringRefZ Name, bool IsLocal, uint8_t StOther, uint8_t Type) - : SymbolKind(K), NeedsCopy(false), NeedsPltAddr(false), IsLocal(IsLocal), + : SymbolKind(K), NeedsPltAddr(false), IsLocal(IsLocal), IsInGlobalMipsGot(false), Is32BitMipsGot(false), IsInIplt(false), IsInIgot(false), Type(Type), StOther(StOther), Name(Name) {} @@ -145,10 +141,9 @@ return false; // Shared symbols resolve to the definition in the DSO. The exceptions are - // symbols with copy relocations (which resolve to .bss) or preempt plt - // entries (which resolve to that plt entry). + // symbols that needs plt entries (which resolve to that plt entry). if (isShared()) - return !NeedsCopy && !NeedsPltAddr; + return !NeedsPltAddr; // That's all that can be preempted in a non-DSO. if (!Config->Shared) @@ -217,11 +212,8 @@ return nullptr; } - if (auto *S = dyn_cast(this)) { - if (S->NeedsCopy) - return S->Section->OutSec; + if (auto *S = dyn_cast(this)) return nullptr; - } if (isa(this)) { if (Config->DefineCommon) Index: lld/trunk/ELF/SyntheticSections.h =================================================================== --- lld/trunk/ELF/SyntheticSections.h +++ lld/trunk/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; }; @@ -760,6 +762,8 @@ template struct In { static InputSection *ARMAttributes; static BuildIdSection *BuildId; + static BssRelSection *Bss; + static BssRelSection *BssRelRo; static InputSection *Common; static DynamicSection *Dynamic; static StringTableSection *DynStrTab; @@ -789,6 +793,8 @@ }; 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: lld/trunk/ELF/SyntheticSections.cpp =================================================================== --- lld/trunk/ELF/SyntheticSections.cpp +++ lld/trunk/ELF/SyntheticSections.cpp @@ -376,10 +376,17 @@ } 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) { @@ -2303,10 +2310,10 @@ 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: lld/trunk/ELF/Writer.cpp =================================================================== --- lld/trunk/ELF/Writer.cpp +++ lld/trunk/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() || @@ -595,7 +596,7 @@ 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; @@ -1159,27 +1160,18 @@ // 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"));