diff options
| -rw-r--r-- | llvm/lib/CodeGen/StackProtector.cpp | 20 | ||||
| -rw-r--r-- | llvm/test/CodeGen/X86/stack-protector.ll | 4 |
2 files changed, 14 insertions, 10 deletions
diff --git a/llvm/lib/CodeGen/StackProtector.cpp b/llvm/lib/CodeGen/StackProtector.cpp index 4c5638092e5..f8c98266dda 100644 --- a/llvm/lib/CodeGen/StackProtector.cpp +++ b/llvm/lib/CodeGen/StackProtector.cpp @@ -312,8 +312,7 @@ static void CreatePrologue(Function *F, Module *M, ReturnInst *RI, /// - The epilogue checks the value stored in the prologue against the original /// value. It calls __stack_chk_fail if they differ. bool StackProtector::InsertStackProtectors() { - BasicBlock *FailBB = 0; // The basic block to jump to if check fails. - BasicBlock *FailBBDom = 0; // FailBB's dominator. + bool HasPrologue = false; AllocaInst *AI = 0; // Place on stack that stores the stack guard. Value *StackGuardVar = 0; // The stack guard variable. @@ -322,10 +321,9 @@ bool StackProtector::InsertStackProtectors() { ReturnInst *RI = dyn_cast<ReturnInst>(BB->getTerminator()); if (!RI) continue; - if (!FailBB) { + if (!HasPrologue) { + HasPrologue = true; CreatePrologue(F, M, RI, TLI, Trip, AI, StackGuardVar); - // Create the basic block to jump to when the guard check fails. - FailBB = CreateFailBB(); } // For each block with a return instruction, convert this: @@ -350,12 +348,16 @@ bool StackProtector::InsertStackProtectors() { // call void @__stack_chk_fail() // unreachable + // Create the fail basic block. + BasicBlock *FailBB = CreateFailBB(); + // Split the basic block before the return instruction. BasicBlock *NewBB = BB->splitBasicBlock(RI, "SP_return"); + // Update the dominator tree if we need to. if (DT && DT->isReachableFromEntry(BB)) { DT->addNewBlock(NewBB, BB); - FailBBDom = FailBBDom ? DT->findNearestCommonDominator(FailBBDom, BB) :BB; + DT->addNewBlock(FailBB, BB); } // Remove default branch instruction to the new BB. @@ -374,10 +376,8 @@ bool StackProtector::InsertStackProtectors() { // Return if we didn't modify any basic blocks. I.e., there are no return // statements in the function. - if (!FailBB) return false; - - if (DT && FailBBDom) - DT->addNewBlock(FailBB, FailBBDom); + if (!HasPrologue) + return false; return true; } diff --git a/llvm/test/CodeGen/X86/stack-protector.ll b/llvm/test/CodeGen/X86/stack-protector.ll index a4dbbb96882..265ec80682b 100644 --- a/llvm/test/CodeGen/X86/stack-protector.ll +++ b/llvm/test/CodeGen/X86/stack-protector.ll @@ -2313,18 +2313,22 @@ entry: ; LINUX-I386-LABEL: test19d: ; LINUX-I386: mov{{l|q}} %gs: ; LINUX-I386: calll __stack_chk_fail +; LINUX-I386-NOT: calll __stack_chk_fail ; LINUX-X64-LABEL: test19d: ; LINUX-X64: mov{{l|q}} %fs: ; LINUX-X64: callq __stack_chk_fail +; LINUX-X64-NOT: callq __stack_chk_fail ; LINUX-KERNEL-X64-LABEL: test19d: ; LINUX-KERNEL-X64: mov{{l|q}} %gs: ; LINUX-KERNEL-X64: callq __stack_chk_fail +; LINUX-KERNEL-X64-NOT: callq ___stack_chk_fail ; DARWIN-X64-LABEL: test19d: ; DARWIN-X64: mov{{l|q}} ___stack_chk_guard ; DARWIN-X64: callq ___stack_chk_fail +; DARWIN-X64-NOT: callq ___stack_chk_fail %c = alloca %struct.pair, align 4 %exn.slot = alloca i8* %ehselector.slot = alloca i32 |
