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[elf2] Implement global dynamic tls. 

llvm-svn: 252979
This commit is contained in:
Michael J. Spencer 2015-11-13 00:28:34 +00:00
parent a6f103f705
commit 627ae703b5
7 changed files with 72 additions and 9 deletions
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8
lld/ELF/InputSection.cpp
View File

@ -126,6 +126,14 @@ void InputSectionBase<ELFT>::relocate(
}
SymbolBody &Body = *File->getSymbolBody(SymIndex)->repl();
if (Type == Target->getTlsGlobalDynamicReloc()) {
Target->relocateOne(BufLoc, BufEnd, Type, AddrLoc,
Out<ELFT>::Got->getEntryAddr(Body) +
getAddend<ELFT>(RI));
continue;
}
uintX_t SymVA = getSymVA<ELFT>(Body);
if (Target->relocNeedsPlt(Type, Body)) {
SymVA = Out<ELFT>::Plt->getEntryAddr(Body);

23
lld/ELF/OutputSections.cpp
View File

@ -80,6 +80,9 @@ GotSection<ELFT>::GotSection()
template <class ELFT> void GotSection<ELFT>::addEntry(SymbolBody *Sym) {
Sym->GotIndex = Target->getGotHeaderEntriesNum() + Entries.size();
Entries.push_back(Sym);
// Global Dynamic TLS entries take two GOT slots.
if (Sym->isTLS())
Entries.push_back(nullptr);
}
template <class ELFT> uint32_t GotSection<ELFT>::addLocalModuleTlsIndex() {
@ -187,8 +190,13 @@ template <class ELFT> void RelocationSection<ELFT>::writeTo(uint8_t *Buf) {
auto *P = reinterpret_cast<Elf_Rel *>(Buf);
Buf += EntrySize;
InputSectionBase<ELFT> &C = Rel.C;
const Elf_Rel &RI = Rel.RI;
// Skip placeholder for global dynamic TLS relocation pair. It was already
// handled by the previous relocation.
if (!Rel.C || !Rel.RI)
continue;
InputSectionBase<ELFT> &C = *Rel.C;
const Elf_Rel &RI = *Rel.RI;
uint32_t SymIndex = RI.getSymbol(Config->Mips64EL);
const ObjectFile<ELFT> &File = *C.getFile();
SymbolBody *Body = File.getSymbolBody(SymIndex);
@ -205,6 +213,17 @@ template <class ELFT> void RelocationSection<ELFT>::writeTo(uint8_t *Buf) {
continue;
}
if (Body && Type == Target->getTlsGlobalDynamicReloc()) {
P->setSymbolAndType(Body->getDynamicSymbolTableIndex(),
Target->getTlsModuleIndexReloc(), Config->Mips64EL);
P->r_offset = Out<ELFT>::Got->getEntryAddr(*Body);
auto *PNext = reinterpret_cast<Elf_Rel *>(Buf);
PNext->setSymbolAndType(Body->getDynamicSymbolTableIndex(),
Target->getTlsOffsetReloc(), Config->Mips64EL);
PNext->r_offset = Out<ELFT>::Got->getEntryAddr(*Body) + sizeof(uintX_t);
continue;
}
bool NeedsCopy = Body && Target->relocNeedsCopy(Type, *Body);
bool NeedsGot = Body && Target->relocNeedsGot(Type, *Body);
bool CanBePreempted = canBePreempted(Body, NeedsGot);

4
lld/ELF/OutputSections.h
View File

@ -170,8 +170,8 @@ private:
template <class ELFT> struct DynamicReloc {
typedef typename llvm::object::ELFFile<ELFT>::Elf_Rel Elf_Rel;
InputSectionBase<ELFT> &C;
const Elf_Rel &RI;
InputSectionBase<ELFT> *C;
const Elf_Rel *RI;
};
template <class ELFT>

3
lld/ELF/Target.cpp
View File

@ -216,7 +216,9 @@ X86_64TargetInfo::X86_64TargetInfo() {
PltReloc = R_X86_64_JUMP_SLOT;
RelativeReloc = R_X86_64_RELATIVE;
TlsLocalDynamicReloc = R_X86_64_TLSLD;
TlsGlobalDynamicReloc = R_X86_64_TLSGD;
TlsModuleIndexReloc = R_X86_64_DTPMOD64;
TlsOffsetReloc = R_X86_64_DTPOFF64;
LazyRelocations = true;
PltEntrySize = 16;
PltZeroEntrySize = 16;
@ -335,6 +337,7 @@ void X86_64TargetInfo::relocateOne(uint8_t *Loc, uint8_t *BufEnd, uint32_t Type,
case R_X86_64_GOTPCREL:
case R_X86_64_PLT32:
case R_X86_64_TLSLD:
case R_X86_64_TLSGD:
write32le(Loc, SA - P);
break;
case R_X86_64_64:

4
lld/ELF/Target.h
View File

@ -30,7 +30,9 @@ public:
unsigned getGotRefReloc() const { return GotRefReloc; }
unsigned getRelativeReloc() const { return RelativeReloc; }
unsigned getTlsLocalDynamicReloc() const { return TlsLocalDynamicReloc; }
unsigned getTlsGlobalDynamicReloc() const { return TlsGlobalDynamicReloc; }
unsigned getTlsModuleIndexReloc() const { return TlsModuleIndexReloc; }
unsigned getTlsOffsetReloc() const { return TlsOffsetReloc; }
unsigned getPltZeroEntrySize() const { return PltZeroEntrySize; }
unsigned getPltEntrySize() const { return PltEntrySize; }
bool supportsLazyRelocations() const { return LazyRelocations; }
@ -70,7 +72,9 @@ protected:
unsigned PltReloc;
unsigned RelativeReloc;
unsigned TlsLocalDynamicReloc = 0;
unsigned TlsGlobalDynamicReloc = 0;
unsigned TlsModuleIndexReloc;
unsigned TlsOffsetReloc;
unsigned PltEntrySize = 8;
unsigned PltZeroEntrySize = 0;
unsigned GotHeaderEntriesNum = 0;

19
lld/ELF/Writer.cpp
View File

@ -203,7 +203,7 @@ void Writer<ELFT>::scanRelocs(
if (Out<ELFT>::LocalModuleTlsIndexOffset == uint32_t(-1)) {
Out<ELFT>::LocalModuleTlsIndexOffset =
Out<ELFT>::Got->addLocalModuleTlsIndex();
Out<ELFT>::RelaDyn->addReloc({C, RI});
Out<ELFT>::RelaDyn->addReloc({&C, &RI});
}
continue;
}
@ -215,6 +215,19 @@ void Writer<ELFT>::scanRelocs(
if (Body)
Body = Body->repl();
if (Body && Body->isTLS()) {
if (Type != Target->getTlsGlobalDynamicReloc())
continue;
if (Body->isInGot())
continue;
Out<ELFT>::Got->addEntry(Body);
Out<ELFT>::RelaDyn->addReloc({&C, &RI});
Out<ELFT>::RelaDyn->addReloc({nullptr, nullptr});
Body->setUsedInDynamicReloc();
continue;
}
bool NeedsGot = false;
bool NeedsPlt = false;
if (Body) {
@ -257,9 +270,9 @@ void Writer<ELFT>::scanRelocs(
if (CBP)
Body->setUsedInDynamicReloc();
if (NeedsPlt && Target->supportsLazyRelocations())
Out<ELFT>::RelaPlt->addReloc({C, RI});
Out<ELFT>::RelaPlt->addReloc({&C, &RI});
else
Out<ELFT>::RelaDyn->addReloc({C, RI});
Out<ELFT>::RelaDyn->addReloc({&C, &RI});
}
}

20
lld/test/elf2/tls-dynamic.s
View File

@ -11,6 +11,10 @@
leaq a@dtpoff(%rax), %rcx
leaq b@dtpoff(%rax), %rcx
.long b@dtpoff, 0
leaq c@tlsgd(%rip), %rdi
rex64
callq __tls_get_addr@PLT
leaq c@dtpoff(%rax), %rcx
.global a
.hidden a
@ -23,8 +27,14 @@ a:
.align 4
b:
.long 0
.global c
.section .tbss,"awT",@nobits
.align 4
c:
.long 0
// Get the address of the got, and check that it has two entries.
// Get the address of the got, and check that it has 4 entries.
// CHECK: Sections [
// CHECK: Name: .got
@ -35,15 +45,18 @@ b:
// CHECK-NEXT: ]
// CHECK-NEXT: Address: 0x20D0
// CHECK-NEXT: Offset:
// CHECK-NEXT: Size: 16
// CHECK-NEXT: Size: 32
// CHECK: Relocations [
// CHECK: Section ({{.+}}) .rela.dyn {
// CHECK-NEXT: 0x20D0 R_X86_64_DTPMOD64 - 0x0
// CHECK-NEXT: 0x20E0 R_X86_64_DTPMOD64 c 0x0
// CHECK-NEXT: 0x20E8 R_X86_64_DTPOFF64 c 0x0
// CHECK-NEXT: }
// 4297 = (0x20D0 + -4) - (0x1000 + 3) // PC relative offset to got entry.
// 4285 = (0x20D0 + -4) - (0x100c + 3) // PC relative offset to got entry.
// 4267 = (0x20E0 + -4) - (0x102e + 3) // PC relative offset to got entry.
// DIS: Disassembly of section .text:
// DIS-NEXT: .text:
@ -57,3 +70,6 @@ b:
// DIS-NEXT: 1028: 00 00
// DIS-NEXT: 102a: 00 00
// DIS-NEXT: 102c: 00 00
// DIS-NEXT: 102e: {{.+}} leaq 4267(%rip), %rdi
// DIS-NEXT: 1035: {{.+}} callq
// DIS-NEXT: 103b: {{.+}} leaq 8(%rax), %rcx