[lld] r262955 - Delete isTlsDynRel.
Rafael Espindola via llvm-commits
llvm-commits at lists.llvm.org
Tue Mar 8 12:24:37 PST 2016
Author: rafael
Date: Tue Mar 8 14:24:36 2016
New Revision: 262955
URL: http://llvm.org/viewvc/llvm-project?rev=262955&view=rev
Log:
Delete isTlsDynRel.
It was a badly specified hack for when a tls relocation should be
propagated to the dynamic relocation table.
This replaces it with a not as bad hack of saying that a local dynamic
tls relocation is never preempted.
I will try to remove even that second hack in the next patch.
Modified:
lld/trunk/ELF/InputSection.cpp
lld/trunk/ELF/OutputSections.cpp
lld/trunk/ELF/OutputSections.h
lld/trunk/ELF/Target.cpp
lld/trunk/ELF/Target.h
lld/trunk/ELF/Writer.cpp
lld/trunk/test/ELF/no-inhibit-exec.s
Modified: lld/trunk/ELF/InputSection.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/InputSection.cpp?rev=262955&r1=262954&r2=262955&view=diff
==============================================================================
--- lld/trunk/ELF/InputSection.cpp (original)
+++ lld/trunk/ELF/InputSection.cpp Tue Mar 8 14:24:36 2016
@@ -271,7 +271,7 @@ void InputSectionBase<ELFT>::relocate(ui
}
uintX_t SymVA = Body->getVA<ELFT>();
- bool CBP = canBePreempted(Body);
+ bool CBP = canBePreempted(Body, Type);
if (Target->needsPlt<ELFT>(Type, *Body)) {
SymVA = Body->getPltVA<ELFT>();
} else if (Target->needsGot(Type, *Body)) {
@@ -284,11 +284,6 @@ void InputSectionBase<ELFT>::relocate(ui
SymVA = Body->getGotVA<ELFT>();
if (Body->IsTls)
Type = Target->getTlsGotRel(Type);
- } else if (!Target->needsCopyRel<ELFT>(Type, *Body) &&
- isa<SharedSymbol<ELFT>>(*Body)) {
- continue;
- } else if (Target->isTlsDynRel(Type, *Body)) {
- continue;
} else if (Target->isSizeRel(Type) && CBP) {
// A SIZE relocation is supposed to set a symbol size, but if a symbol
// can be preempted, the size at runtime may be different than link time.
@@ -302,6 +297,8 @@ void InputSectionBase<ELFT>::relocate(ui
SymVA = getMipsGpAddr<ELFT>() - AddrLoc + 4;
else if (Body == Config->MipsLocalGp)
SymVA = getMipsGpAddr<ELFT>();
+ } else if (!Target->needsCopyRel<ELFT>(Type, *Body) && CBP) {
+ continue;
}
uintX_t Size = Body->getSize<ELFT>();
Target->relocateOne(BufLoc, BufEnd, Type, AddrLoc, SymVA + A, Size + A,
Modified: lld/trunk/ELF/OutputSections.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/OutputSections.cpp?rev=262955&r1=262954&r2=262955&view=diff
==============================================================================
--- lld/trunk/ELF/OutputSections.cpp (original)
+++ lld/trunk/ELF/OutputSections.cpp Tue Mar 8 14:24:36 2016
@@ -176,7 +176,7 @@ template <class ELFT> void GotSection<EL
// for detailed description:
// ftp://www.linux-mips.org/pub/linux/mips/doc/ABI/mipsabi.pdf
// As the first approach, we can just store addresses for all symbols.
- if (Config->EMachine != EM_MIPS && canBePreempted(B))
+ if (Config->EMachine != EM_MIPS && canBePreempted(B, 0))
continue; // The dynamic linker will take care of it.
uintX_t VA = B->getVA<ELFT>();
write<uintX_t, ELFT::TargetEndianness, sizeof(uintX_t)>(Entry, VA);
@@ -932,9 +932,16 @@ elf::getLocalRelTarget(const ObjectFile<
// Returns true if a symbol can be replaced at load-time by a symbol
// with the same name defined in other ELF executable or DSO.
-bool elf::canBePreempted(const SymbolBody *Body) {
+bool elf::canBePreempted(const SymbolBody *Body, unsigned Type) {
if (!Body)
return false; // Body is a local symbol.
+
+ // FIXME: Both gold and bfd consider that a local dynamic tls relocation to
+ // a symbol will not be preempted. Is that actually relevant? The compiler
+ // should not use it if the symbol can be preempted.
+ if (Target->isTlsLocalDynamicRel(Type))
+ return false;
+
if (Body->isShared())
return true;
Modified: lld/trunk/ELF/OutputSections.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/OutputSections.h?rev=262955&r1=262954&r2=262955&view=diff
==============================================================================
--- lld/trunk/ELF/OutputSections.h (original)
+++ lld/trunk/ELF/OutputSections.h Tue Mar 8 14:24:36 2016
@@ -53,7 +53,7 @@ getLocalRelTarget(const ObjectFile<ELFT>
const llvm::object::Elf_Rel_Impl<ELFT, IsRela> &Rel,
typename llvm::object::ELFFile<ELFT>::uintX_t Addend);
-bool canBePreempted(const SymbolBody *Body);
+bool canBePreempted(const SymbolBody *Body, unsigned Type);
bool isValidCIdentifier(StringRef S);
Modified: lld/trunk/ELF/Target.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Target.cpp?rev=262955&r1=262954&r2=262955&view=diff
==============================================================================
--- lld/trunk/ELF/Target.cpp (original)
+++ lld/trunk/ELF/Target.cpp Tue Mar 8 14:24:36 2016
@@ -87,7 +87,6 @@ public:
bool isTlsLocalDynamicRel(uint32_t Type) const override;
bool isTlsGlobalDynamicRel(uint32_t Type) const override;
bool isTlsInitialExecRel(uint32_t Type) const override;
- bool isTlsDynRel(uint32_t Type, const SymbolBody &S) const override;
void writeGotPlt(uint8_t *Buf, uint64_t Plt) const override;
void writePltZero(uint8_t *Buf) const override;
void writePlt(uint8_t *Buf, uint64_t GotEntryAddr, uint64_t PltEntryAddr,
@@ -123,7 +122,6 @@ public:
bool isTlsLocalDynamicRel(uint32_t Type) const override;
bool isTlsGlobalDynamicRel(uint32_t Type) const override;
bool isTlsInitialExecRel(uint32_t Type) const override;
- bool isTlsDynRel(uint32_t Type, const SymbolBody &S) const override;
void writeGotPltHeader(uint8_t *Buf) const override;
void writeGotPlt(uint8_t *Buf, uint64_t Plt) const override;
void writePltZero(uint8_t *Buf) const override;
@@ -185,7 +183,6 @@ public:
void writePlt(uint8_t *Buf, uint64_t GotEntryAddr, uint64_t PltEntryAddr,
int32_t Index, unsigned RelOff) const override;
uint32_t getTlsGotRel(uint32_t Type) const override;
- bool isTlsDynRel(uint32_t Type, const SymbolBody &S) const override;
bool isRelRelative(uint32_t Type) const override;
bool needsCopyRelImpl(uint32_t Type) const override;
bool needsGot(uint32_t Type, SymbolBody &S) const override;
@@ -281,7 +278,7 @@ bool TargetInfo::canRelaxTls(uint32_t Ty
// Initial-Exec relocs can be relaxed to Local-Exec if the symbol is locally
// defined.
if (isTlsInitialExecRel(Type))
- return !canBePreempted(S);
+ return !canBePreempted(S, Type);
return false;
}
@@ -304,10 +301,6 @@ bool TargetInfo::needsCopyRel(uint32_t T
return mayNeedCopy<ELFT>(S) && needsCopyRelImpl(Type);
}
-bool TargetInfo::isTlsDynRel(uint32_t Type, const SymbolBody &S) const {
- return false;
-}
-
bool TargetInfo::isGotRelative(uint32_t Type) const { return false; }
bool TargetInfo::isHintRel(uint32_t Type) const { return false; }
bool TargetInfo::isRelRelative(uint32_t Type) const { return true; }
@@ -324,7 +317,7 @@ TargetInfo::PltNeed TargetInfo::needsPlt
const SymbolBody &S) const {
if (isGnuIFunc<ELFT>(S))
return Plt_Explicit;
- if (canBePreempted(&S) && needsPltImpl(Type))
+ if (canBePreempted(&S, Type) && needsPltImpl(Type))
return Plt_Explicit;
// This handles a non PIC program call to function in a shared library.
@@ -428,15 +421,6 @@ bool X86TargetInfo::isTlsInitialExecRel(
return Type == R_386_TLS_IE || Type == R_386_TLS_GOTIE;
}
-bool X86TargetInfo::isTlsDynRel(uint32_t Type, const SymbolBody &S) const {
- if (Type == R_386_TLS_LE || Type == R_386_TLS_LE_32 ||
- Type == R_386_TLS_GOTIE)
- return Config->Shared;
- if (Type == R_386_TLS_IE)
- return canBePreempted(&S);
- return Type == R_386_TLS_GD;
-}
-
void X86TargetInfo::writePltZero(uint8_t *Buf) const {
// Executable files and shared object files have
// separate procedure linkage tables.
@@ -486,7 +470,7 @@ bool X86TargetInfo::needsCopyRelImpl(uin
bool X86TargetInfo::needsGot(uint32_t Type, SymbolBody &S) const {
if (S.IsTls && Type == R_386_TLS_GD)
- return Target->canRelaxTls(Type, &S) && canBePreempted(&S);
+ return Target->canRelaxTls(Type, &S) && canBePreempted(&S, Type);
if (Type == R_386_TLS_GOTIE || Type == R_386_TLS_IE)
return !canRelaxTls(Type, &S);
return Type == R_386_GOT32 || needsPlt<ELF32LE>(Type, S);
@@ -564,7 +548,7 @@ size_t X86TargetInfo::relaxTls(uint8_t *
const SymbolBody *S) const {
switch (Type) {
case R_386_TLS_GD:
- if (canBePreempted(S))
+ if (canBePreempted(S, Type))
relocateTlsGdToIe(Loc, BufEnd, P, SA);
else
relocateTlsGdToLe(Loc, BufEnd, P, SA);
@@ -748,7 +732,7 @@ bool X86_64TargetInfo::refersToGotEntry(
bool X86_64TargetInfo::needsGot(uint32_t Type, SymbolBody &S) const {
if (Type == R_X86_64_TLSGD)
- return Target->canRelaxTls(Type, &S) && canBePreempted(&S);
+ return Target->canRelaxTls(Type, &S) && canBePreempted(&S, Type);
if (Type == R_X86_64_GOTTPOFF)
return !canRelaxTls(Type, &S);
return refersToGotEntry(Type) || needsPlt<ELF64LE>(Type, S);
@@ -774,11 +758,8 @@ bool X86_64TargetInfo::pointsToLocalDyna
}
bool X86_64TargetInfo::isTlsLocalDynamicRel(uint32_t Type) const {
- return Type == R_X86_64_DTPOFF32 || Type == R_X86_64_TLSLD;
-}
-
-bool X86_64TargetInfo::isTlsDynRel(uint32_t Type, const SymbolBody &S) const {
- return Type == R_X86_64_GOTTPOFF || Type == R_X86_64_TLSGD;
+ return Type == R_X86_64_DTPOFF32 || Type == R_X86_64_DTPOFF64 ||
+ Type == R_X86_64_TLSLD;
}
bool X86_64TargetInfo::needsPltImpl(uint32_t Type) const {
@@ -918,7 +899,7 @@ size_t X86_64TargetInfo::relaxTls(uint8_
relocateTlsIeToLe(Loc, BufEnd, P, SA);
return 0;
case R_X86_64_TLSGD: {
- if (canBePreempted(S))
+ if (canBePreempted(S, Type))
relocateTlsGdToIe(Loc, BufEnd, P, SA);
else
relocateTlsGdToLe(Loc, BufEnd, P, SA);
@@ -1309,15 +1290,6 @@ uint32_t AArch64TargetInfo::getTlsGotRel
return Type;
}
-bool AArch64TargetInfo::isTlsDynRel(uint32_t Type, const SymbolBody &S) const {
- return Type == R_AARCH64_TLSDESC_ADR_PAGE21 ||
- Type == R_AARCH64_TLSDESC_LD64_LO12_NC ||
- Type == R_AARCH64_TLSDESC_ADD_LO12_NC ||
- Type == R_AARCH64_TLSDESC_CALL ||
- Type == R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21 ||
- Type == R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC;
-}
-
bool AArch64TargetInfo::needsCopyRelImpl(uint32_t Type) const {
switch (Type) {
default:
@@ -1494,7 +1466,7 @@ size_t AArch64TargetInfo::relaxTls(uint8
case R_AARCH64_TLSDESC_LD64_LO12_NC:
case R_AARCH64_TLSDESC_ADD_LO12_NC:
case R_AARCH64_TLSDESC_CALL: {
- if (canBePreempted(S))
+ if (canBePreempted(S, Type))
fatal("Unsupported TLS optimization");
uint64_t X = S ? S->getVA<ELF64LE>() : SA;
relocateTlsGdToLe(Type, Loc, BufEnd, P, X);
Modified: lld/trunk/ELF/Target.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Target.h?rev=262955&r1=262954&r2=262955&view=diff
==============================================================================
--- lld/trunk/ELF/Target.h (original)
+++ lld/trunk/ELF/Target.h Tue Mar 8 14:24:36 2016
@@ -27,7 +27,6 @@ public:
virtual bool isTlsLocalDynamicRel(uint32_t Type) const;
virtual bool isTlsGlobalDynamicRel(uint32_t Type) const;
virtual uint32_t getDynRel(uint32_t Type) const { return Type; }
- virtual bool isTlsDynRel(uint32_t Type, const SymbolBody &S) const;
virtual uint32_t getTlsGotRel(uint32_t Type) const { return TlsGotRel; }
virtual void writeGotHeader(uint8_t *Buf) const {}
virtual void writeGotPltHeader(uint8_t *Buf) const {}
Modified: lld/trunk/ELF/Writer.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Writer.cpp?rev=262955&r1=262954&r2=262955&view=diff
==============================================================================
--- lld/trunk/ELF/Writer.cpp (original)
+++ lld/trunk/ELF/Writer.cpp Tue Mar 8 14:24:36 2016
@@ -281,10 +281,10 @@ static bool handleTlsRelocation(uint32_t
}
return true;
}
- if (!canBePreempted(Body))
+ if (!canBePreempted(Body, Type))
return true;
}
- return !Target->isTlsDynRel(Type, *Body);
+ return false;
}
// The reason we have to do this early scan is as follows
@@ -327,7 +327,7 @@ void Writer<ELFT>::scanRelocs(
if (Body)
Body = Body->repl();
- bool CBP = canBePreempted(Body);
+ bool CBP = canBePreempted(Body, Type);
if (handleTlsRelocation<ELFT>(Type, Body, C, RI))
continue;
Modified: lld/trunk/test/ELF/no-inhibit-exec.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/no-inhibit-exec.s?rev=262955&r1=262954&r2=262955&view=diff
==============================================================================
--- lld/trunk/test/ELF/no-inhibit-exec.s (original)
+++ lld/trunk/test/ELF/no-inhibit-exec.s Tue Mar 8 14:24:36 2016
@@ -6,7 +6,7 @@
# CHECK: Disassembly of section .text:
# CHECK-NEXT: _start
-# CHECK-NEXT: 11000: e8 fb ef fe ff callq -69637
+# CHECK-NEXT: 11000: e8 00 00 00 00 callq 0
# next code will not link without noinhibit-exec flag
# because of undefined symbol _bar
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