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Pull in r353299 from upstream lld trunk (by George Rimar):

Browse Source 
Recommit r353293 "[LLD][ELF] - Set DF_STATIC_TLS flag for i386 target."

  With the following changes:
  1) Compilation fix:
  std::atomic<bool> HasStaticTlsModel = false; ->
  std::atomic<bool> HasStaticTlsModel{false};

  2) Adjusted the comment in code.

  Initial commit message:

  DF_STATIC_TLS flag indicates that the shared object or executable
  contains code using a static thread-local storage scheme.

  Patch checks if IE/LE relocations were used to check if the code uses
  a static model. If so it sets the DF_STATIC_TLS flag.

  Differential revision: https://reviews.llvm.org/D57749

Pull in r353378 from upstream lld trunk (by George Rimar):

  [LLD][ELF] - Set DF_STATIC_TLS flag for X64 target

  This is the same as D57749, but for x64 target.

  "ELF Handling For Thread-Local Storage" p41 says
  (https://www.akkadia.org/drepper/tls.pdf):
  R_X86_64_GOTTPOFF relocation is used for IE TLS models.
  Hence if linker sees this relocation we should add DF_STATIC_TLS flag.

  Differential revision: https://reviews.llvm.org/D57821

This adds support to lld for the DF_STATIC_TLS flag in shared objects,
which signals to the dynamic linker that the shared object requires
static thread local storage.

See also:	https://reviews.freebsd.org/D19072
MFC after:	1 week
This commit is contained in:
Dimitry Andric 2019-02-21 18:41:41 +00:00
parent 61ebc359ca
commit 1bf8c89f28
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=344444
4 changed files with 15 additions and 0 deletions
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8
contrib/llvm/tools/lld/ELF/Arch/X86.cpp
View File

@ -70,6 +70,14 @@ static bool hasBaseReg(uint8_t ModRM) { return (ModRM & 0xc7) != 0x5; }
RelExpr X86::getRelExpr(RelType Type, const Symbol &S,
const uint8_t *Loc) const {
// There are 4 different TLS variable models with varying degrees of
// flexibility and performance. LocalExec and InitialExec models are fast but
// less-flexible models. If they are in use, we set DF_STATIC_TLS flag in the
// dynamic section to let runtime know about that.
if (Type == R_386_TLS_LE || Type == R_386_TLS_LE_32 || Type == R_386_TLS_IE ||
Type == R_386_TLS_GOTIE)
Config->HasStaticTlsModel = true;
switch (Type) {
case R_386_8:
case R_386_16:

3
contrib/llvm/tools/lld/ELF/Arch/X86_64.cpp
View File

@ -76,6 +76,9 @@ template <class ELFT> X86_64<ELFT>::X86_64() {
template <class ELFT>
RelExpr X86_64<ELFT>::getRelExpr(RelType Type, const Symbol &S,
const uint8_t *Loc) const {
if (Type == R_X86_64_GOTTPOFF)
Config->HasStaticTlsModel = true;
switch (Type) {
case R_X86_64_8:
case R_X86_64_16:

2
contrib/llvm/tools/lld/ELF/Config.h
View File

@ -18,6 +18,7 @@
#include "llvm/Support/CachePruning.h"
#include "llvm/Support/CodeGen.h"
#include "llvm/Support/Endian.h"
#include <atomic>
#include <vector>
namespace lld {
@ -81,6 +82,7 @@ struct VersionDefinition {
// and such fields have the same name as the corresponding options.
// Most fields are initialized by the driver.
struct Configuration {
std::atomic<bool> HasStaticTlsModel{false};
uint8_t OSABI = 0;
llvm::CachePruningPolicy ThinLTOCachePolicy;
llvm::StringMap<uint64_t> SectionStartMap;

2
contrib/llvm/tools/lld/ELF/SyntheticSections.cpp
View File

@ -1282,6 +1282,8 @@ template <class ELFT> void DynamicSection<ELFT>::finalizeContents() {
}
if (!Config->ZText)
DtFlags |= DF_TEXTREL;
if (Config->HasStaticTlsModel)
DtFlags |= DF_STATIC_TLS;
if (DtFlags)
addInt(DT_FLAGS, DtFlags);