Author: Pengfei Wang Date: 2020-05-18T18:47:27-07:00 New Revision: bf1f5caf20281eb312e1bcb0a9d32bd6a5a2e289
URL: https://github.com/llvm/llvm-project/commit/bf1f5caf20281eb312e1bcb0a9d32bd6a5a2e289 DIFF: https://github.com/llvm/llvm-project/commit/bf1f5caf20281eb312e1bcb0a9d32bd6a5a2e289.diff LOG: CET for Exception Handle Summary: Bug fix for https://bugs.llvm.org/show_bug.cgi?id=45182 Exception handle may indirectly jump to catch pad, So we should add ENDBR instruction before catch pad instructions. Reviewers: craig.topper, hjl.tools, LuoYuanke, annita.zhang, pengfei Reviewed By: LuoYuanke Subscribers: hiraditya, llvm-commits Patch By: Xiang Zhang (xiangzhangllvm) Differential Revision: https://reviews.llvm.org/D76190 (cherry picked from commit 974d649f8eaf3026ccb9d1b77bdec55da25366e5) Added: llvm/test/CodeGen/X86/indirect-branch-tracking-eh.ll Modified: llvm/lib/Target/X86/X86IndirectBranchTracking.cpp Removed: ################################################################################ diff --git a/llvm/lib/Target/X86/X86IndirectBranchTracking.cpp b/llvm/lib/Target/X86/X86IndirectBranchTracking.cpp index 48d0d8a35704..743df41a00ff 100644 --- a/llvm/lib/Target/X86/X86IndirectBranchTracking.cpp +++ b/llvm/lib/Target/X86/X86IndirectBranchTracking.cpp @@ -127,11 +127,18 @@ bool X86IndirectBranchTrackingPass::runOnMachineFunction(MachineFunction &MF) { if (MBB.hasAddressTaken()) Changed |= addENDBR(MBB, MBB.begin()); + // Exception handle may indirectly jump to catch pad, So we should add + // ENDBR before catch pad instructions. + bool EHPadIBTNeeded = MBB.isEHPad(); + for (MachineBasicBlock::iterator I = MBB.begin(); I != MBB.end(); ++I) { - if (!I->isCall()) - continue; - if (IsCallReturnTwice(I->getOperand(0))) + if (I->isCall() && IsCallReturnTwice(I->getOperand(0))) Changed |= addENDBR(MBB, std::next(I)); + + if (EHPadIBTNeeded && I->isEHLabel()) { + Changed |= addENDBR(MBB, std::next(I)); + EHPadIBTNeeded = false; + } } } return Changed; diff --git a/llvm/test/CodeGen/X86/indirect-branch-tracking-eh.ll b/llvm/test/CodeGen/X86/indirect-branch-tracking-eh.ll new file mode 100644 index 000000000000..c14e82dc8f3d --- /dev/null +++ b/llvm/test/CodeGen/X86/indirect-branch-tracking-eh.ll @@ -0,0 +1,31 @@ +; RUN: llc -mtriple=x86_64-unknown-unknown < %s | FileCheck %s +; RUN: llc -mtriple=i386-unknown-unknown < %s | FileCheck %s + +;There should be 2 endbr* instruction at entry and catch pad. +;CHECK-COUNT-2: endbr + +declare void @_Z20function_that_throwsv() +declare i32 @__gxx_personality_sj0(...) +declare i8* @__cxa_begin_catch(i8*) +declare void @__cxa_end_catch() + +define void @test8() personality i8* bitcast (i32 (...)* @__gxx_personality_sj0 to i8*) { +entry: + invoke void @_Z20function_that_throwsv() + to label %try.cont unwind label %lpad + +lpad: + %0 = landingpad { i8*, i32 } + catch i8* null + %1 = extractvalue { i8*, i32 } %0, 0 + %2 = tail call i8* @__cxa_begin_catch(i8* %1) + tail call void @__cxa_end_catch() + br label %try.cont + +try.cont: + ret void +} + +!llvm.module.flags = !{!0} + +!0 = !{i32 4, !"cf-protection-branch", i32 1} _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
