From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Tue, 8 Mar 2016 20:24:36 +0000 (+0000)
Subject: Delete isTlsDynRel.
X-Git-Tag: llvmorg-3.9.0-rc1~12236
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=1f04c4488501deed5b6bfac098815bec14b8bb73;p=platform%2Fupstream%2Fllvm.git

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.

llvm-svn: 262955
---

diff --git a/lld/ELF/InputSection.cpp b/lld/ELF/InputSection.cpp
index 9e0ecd9..e4e876f 100644
--- a/lld/ELF/InputSection.cpp
+++ b/lld/ELF/InputSection.cpp
@@ -271,7 +271,7 @@ void InputSectionBase<ELFT>::relocate(uint8_t *Buf, uint8_t *BufEnd,
     }
 
     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(uint8_t *Buf, uint8_t *BufEnd,
         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(uint8_t *Buf, uint8_t *BufEnd,
         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,
diff --git a/lld/ELF/OutputSections.cpp b/lld/ELF/OutputSections.cpp
index 8c294f6..b825ba7 100644
--- a/lld/ELF/OutputSections.cpp
+++ b/lld/ELF/OutputSections.cpp
@@ -176,7 +176,7 @@ template <class ELFT> void GotSection<ELFT>::writeTo(uint8_t *Buf) {
     // 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<ELFT> &File,
 
 // 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;
 
diff --git a/lld/ELF/OutputSections.h b/lld/ELF/OutputSections.h
index 6810352..90db2cd 100644
--- a/lld/ELF/OutputSections.h
+++ b/lld/ELF/OutputSections.h
@@ -53,7 +53,7 @@ getLocalRelTarget(const ObjectFile<ELFT> &File,
                   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);
 
diff --git a/lld/ELF/Target.cpp b/lld/ELF/Target.cpp
index c38a087..83cfef7 100644
--- a/lld/ELF/Target.cpp
+++ b/lld/ELF/Target.cpp
@@ -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 Type, const SymbolBody *S) const {
   // 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 Type, const SymbolBody &S) const {
   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(uint32_t Type,
                                          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(uint32_t Type) const {
   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(uint32_t Type) const {
 
 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 *Loc, uint8_t *BufEnd, uint32_t Type,
                                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(uint32_t Type) const {
 
 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::pointsToLocalDynamicGotEntry(uint32_t Type) const {
 }
 
 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_t *Loc, uint8_t *BufEnd, uint32_t Type,
     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(uint32_t Type) const {
   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_t *Loc, uint8_t *BufEnd, uint32_t Type,
   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);
diff --git a/lld/ELF/Target.h b/lld/ELF/Target.h
index 1f9b614..ab4defa 100644
--- a/lld/ELF/Target.h
+++ b/lld/ELF/Target.h
@@ -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 {}
diff --git a/lld/ELF/Writer.cpp b/lld/ELF/Writer.cpp
index b67e7f1..d2de22f 100644
--- a/lld/ELF/Writer.cpp
+++ b/lld/ELF/Writer.cpp
@@ -281,10 +281,10 @@ static bool handleTlsRelocation(uint32_t Type, SymbolBody *Body,
       }
       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;
 
diff --git a/lld/test/ELF/no-inhibit-exec.s b/lld/test/ELF/no-inhibit-exec.s
index fe2240b..2f2a62b 100644
--- a/lld/test/ELF/no-inhibit-exec.s
+++ b/lld/test/ELF/no-inhibit-exec.s
@@ -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