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Faster stack-protector for Android/AArch64.

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Bionic has a defined thread-local location for the stack protector
cookie. Emit a direct load instead of going through __stack_chk_guard.

llvm-svn: 265481
This commit is contained in:
Evgeniy Stepanov
2016-04-05 22:41:50 +00:00
parent f8bdd88cd9
commit dde29e2799
8 changed files with 89 additions and 32 deletions
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26
llvm/lib/CodeGen/StackProtector.cpp
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@@ -333,24 +333,20 @@ static bool CreatePrologue(Function *F, Module *M, ReturnInst *RI,
AllocaInst *&AI, Value *&StackGuardVar) {
bool SupportsSelectionDAGSP = false;
PointerType *PtrTy = Type::getInt8PtrTy(RI->getContext());
unsigned AddressSpace, Offset;
if (TLI->getStackCookieLocation(AddressSpace, Offset)) {
Constant *OffsetVal =
ConstantInt::get(Type::getInt32Ty(RI->getContext()), Offset);
IRBuilder<> B(&F->getEntryBlock().front());
StackGuardVar =
ConstantExpr::getIntToPtr(OffsetVal, PointerType::get(PtrTy,
AddressSpace));
} else if (TT.isOSOpenBSD()) {
StackGuardVar = M->getOrInsertGlobal("__guard_local", PtrTy);
cast<GlobalValue>(StackGuardVar)
->setVisibility(GlobalValue::HiddenVisibility);
} else {
SupportsSelectionDAGSP = true;
StackGuardVar = M->getOrInsertGlobal("__stack_chk_guard", PtrTy);
StackGuardVar = TLI->getStackCookieLocation(B);
if (!StackGuardVar) {
if (TT.isOSOpenBSD()) {
StackGuardVar = M->getOrInsertGlobal("__guard_local", PtrTy);
cast<GlobalValue>(StackGuardVar)
->setVisibility(GlobalValue::HiddenVisibility);
} else {
SupportsSelectionDAGSP = true;
StackGuardVar = M->getOrInsertGlobal("__stack_chk_guard", PtrTy);
}
}
IRBuilder<> B(&F->getEntryBlock().front());
AI = B.CreateAlloca(PtrTy, nullptr, "StackGuardSlot");
LoadInst *LI = B.CreateLoad(StackGuardVar, "StackGuard");
B.CreateCall(Intrinsic::getDeclaration(M, Intrinsic::stackprotector),