Implement the stack protector stack accesses via intrinsics:
- stackprotector_prologue creates a stack object and stores the guard there.
- stackprotector_epilogue reads the stack guard from the stack position created
by stackprotector_prologue.
- The PrologEpilogInserter was changed to make sure that the stack guard is
first on the stack frame.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58791 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/StackProtector.cpp b/lib/CodeGen/StackProtector.cpp
index 5cd4c67..659f8a0 100644
--- a/lib/CodeGen/StackProtector.cpp
+++ b/lib/CodeGen/StackProtector.cpp
@@ -20,6 +20,7 @@
#include "llvm/DerivedTypes.h"
#include "llvm/Function.h"
#include "llvm/Instructions.h"
+#include "llvm/Intrinsics.h"
#include "llvm/Module.h"
#include "llvm/Pass.h"
#include "llvm/ADT/APInt.h"
@@ -110,16 +111,15 @@
// onto the stack.
BasicBlock &Entry = F->getEntryBlock();
Instruction *InsertPt = &Entry.front();
+
const PointerType *GuardTy = PointerType::getUnqual(Type::Int8Ty);
// The global variable for the stack guard.
Constant *StackGuardVar = M->getOrInsertGlobal("__stack_chk_guard", GuardTy);
-
- // The place on the stack that the stack protector guard is kept.
- AllocaInst *StackProtFrameSlot =
- new AllocaInst(GuardTy, "StackProt_Frame", InsertPt);
LoadInst *LI = new LoadInst(StackGuardVar, "StackGuard", false, InsertPt);
- new StoreInst(LI, StackProtFrameSlot, false, InsertPt);
+ CallInst::
+ Create(Intrinsic::getDeclaration(M, Intrinsic::stackprotector_prologue),
+ LI, "", InsertPt);
// Create the basic block to jump to when the guard check fails.
BasicBlock *FailBB = CreateFailBB();
@@ -137,7 +137,7 @@
// %1 = load __stack_chk_guard
// %2 = load <stored stack guard>
// %3 = cmp i1 %1, %2
- // br i1 %3, label %SPRet, label %CallStackCheckFailBlk
+ // br i1 %3, label %SP_return, label %CallStackCheckFailBlk
//
// SP_return:
// ret ...
@@ -161,9 +161,11 @@
F->getBasicBlockList().insert(InsPt, NewBB);
// Generate the stack protector instructions in the old basic block.
- LoadInst *LI2 = new LoadInst(StackGuardVar, "", false, BB);
- LoadInst *LI1 = new LoadInst(StackProtFrameSlot, "", true, BB);
- ICmpInst *Cmp = new ICmpInst(CmpInst::ICMP_EQ, LI1, LI2, "", BB);
+ LoadInst *LI1 = new LoadInst(StackGuardVar, "", false, BB);
+ CallInst *CI = CallInst::
+ Create(Intrinsic::getDeclaration(M, Intrinsic::stackprotector_epilogue),
+ "", BB);
+ ICmpInst *Cmp = new ICmpInst(CmpInst::ICMP_EQ, CI, LI1, "", BB);
BranchInst::Create(NewBB, FailBB, Cmp, BB);
}