[PATCH] D76900: Enable IBT(Indirect Branch Tracking) in JIT with CET(Control-flow Enforcement Technology)

[Xiang Zhang via Phabricator via llvm-commits]

xiangzhangllvm added a comment.

If "1 Check CET in JIT instead of checking -fcf-protection-branch" can't let VNC passed. The crash must happen at "Take address of a internal function."

This is not a IBT problem only for JIT, but also the static llvm compiler, e.g. llc.
And it may unable to track these calling through function address, because these function address may be calculated out in runtime or written in a big table.

and it really seems some disaccord/unbeautiful to add "isJITwithCET" for the old patch.

I think we should change the condition from

  if ((**isJITwithCET ||**
       MF.getFunction().hasAddressTaken() ||
       !MF.getFunction().hasLocalLinkage()) &&
      !MF.getFunction().doesNoCfCheck()) {
    auto MBB = MF.begin();
    Changed |= addENDBR(*MBB, MBB->begin());
  }

to

  if (!MF.getFunction().doesNoCfCheck()) {
    auto MBB = MF.begin();
    Changed |= addENDBR(*MBB, MBB->begin());
  }


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D76900/new/

https://reviews.llvm.org/D76900