Fix up -fstack-protector on linux to use the segment
registers. Split out testcases per architecture and os
now.
Patch from Nelson Elhage.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107640 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/StackProtector.cpp b/lib/CodeGen/StackProtector.cpp
index 8a6a727..e318afe 100644
--- a/lib/CodeGen/StackProtector.cpp
+++ b/lib/CodeGen/StackProtector.cpp
@@ -136,7 +136,7 @@
bool StackProtector::InsertStackProtectors() {
BasicBlock *FailBB = 0; // The basic block to jump to if check fails.
AllocaInst *AI = 0; // Place on stack that stores the stack guard.
- Constant *StackGuardVar = 0; // The stack guard variable.
+ Value *StackGuardVar = 0; // The stack guard variable.
for (Function::iterator I = F->begin(), E = F->end(); I != E; ) {
BasicBlock *BB = I++;
@@ -155,7 +155,20 @@
//
PointerType *PtrTy = PointerType::getUnqual(
Type::getInt8Ty(RI->getContext()));
- StackGuardVar = M->getOrInsertGlobal("__stack_chk_guard", PtrTy);
+
+ unsigned AddressSpace, Offset;
+ if (TLI->getStackCookieLocation(AddressSpace, Offset)) {
+ Constant *ASPtr = Constant::getNullValue(
+ PointerType::get(Type::getInt8Ty(RI->getContext()), AddressSpace));
+ APInt OffsetInt(32, Offset);
+ Constant *OffsetVal = Constant::getIntegerValue(
+ Type::getInt32Ty(RI->getContext()), OffsetInt);
+ StackGuardVar = ConstantExpr::getPointerCast(
+ ConstantExpr::getGetElementPtr(ASPtr, &OffsetVal, 1),
+ PointerType::get(PtrTy, AddressSpace));
+ } else {
+ StackGuardVar = M->getOrInsertGlobal("__stack_chk_guard", PtrTy);
+ }
BasicBlock &Entry = F->getEntryBlock();
Instruction *InsPt = &Entry.front();
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 423a076..8a0a04e 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -1189,6 +1189,27 @@
return F->hasFnAttr(Attribute::OptimizeForSize) ? 0 : 4;
}
+bool X86TargetLowering::getStackCookieLocation(unsigned &AddressSpace,
+ unsigned &Offset) const {
+ if (!Subtarget->isTargetLinux())
+ return false;
+
+ if (Subtarget->is64Bit()) {
+ // %fs:0x28, unless we're using a Kernel code model, in which case it's %gs:
+ Offset = 0x28;
+ if (getTargetMachine().getCodeModel() == CodeModel::Kernel)
+ AddressSpace = 256;
+ else
+ AddressSpace = 257;
+ } else {
+ // %gs:0x14 on i386
+ Offset = 0x14;
+ AddressSpace = 256;
+ }
+ return true;
+}
+
+
//===----------------------------------------------------------------------===//
// Return Value Calling Convention Implementation
//===----------------------------------------------------------------------===//
diff --git a/lib/Target/X86/X86ISelLowering.h b/lib/Target/X86/X86ISelLowering.h
index a7de0b1..82cef27 100644
--- a/lib/Target/X86/X86ISelLowering.h
+++ b/lib/Target/X86/X86ISelLowering.h
@@ -593,6 +593,12 @@
/// getFunctionAlignment - Return the Log2 alignment of this function.
virtual unsigned getFunctionAlignment(const Function *F) const;
+ /// getStackCookieLocation - Return true if the target stores stack
+ /// protector cookies at a fixed offset in some non-standard address
+ /// space, and populates the address space and offset as
+ /// appropriate.
+ virtual bool getStackCookieLocation(unsigned &AddressSpace, unsigned &Offset) const;
+
private:
/// Subtarget - Keep a pointer to the X86Subtarget around so that we can
/// make the right decision when generating code for different targets.