[llvm] [BOLT][AArch64] Support for pointer authentication (PR #117578)

[Paschalis Mpeis via llvm-commits]

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@@ -0,0 +1,241 @@
+#include "bolt/Passes/InsertNegateRAStatePass.h"
+#include "bolt/Core/BinaryFunction.h"
+#include "bolt/Core/ParallelUtilities.h"
+#include "bolt/Utils/CommandLineOpts.h"
+#include <cstdlib>
+#include <fstream>
+#include <iterator>
+
+using namespace llvm;
+
+namespace llvm {
+namespace bolt {
+
+void InsertNegateRAState::runOnFunction(BinaryFunction &BF) {
+  BinaryContext &BC = BF.getBinaryContext();
+
+  if (BF.getState() == BinaryFunction::State::Empty) {
+    return;
+  }
+
+  if (BF.getState() != BinaryFunction::State::CFG &&
+      BF.getState() != BinaryFunction::State::CFG_Finalized) {
+    BC.outs() << "BOLT-INFO: No CFG for " << BF.getPrintName()
+              << " in InsertNegateRAStatePass\n";
+    return;
+  }
+
+  if (BF.isIgnored())
+    return;
+
+  if (!addNegateRAStateAfterPacOrAuth(BF)) {
+    // none inserted, function doesn't need more work
+    return;
+  }
+
+  auto FirstBB = BF.begin();
+  explore_call_graph(BC, &(*FirstBB));
+
+  // We have to do the walk again, starting from any undiscovered autiasp
+  // instructions, because some autiasp might not be reachable because of
+  // indirect branches but we know that autiasp block should have a Signed
+  // state, so we can work out other Unkown states starting from these nodes.
+  for (BinaryBasicBlock &BB : BF) {
+    if (BBhasAUTH(BC, &BB) && BB.isRAStateUnknown()) {
+      BB.setRASigned();
+      explore_call_graph(BC, &BB);
+    }
+  }
+
+  // insert negateRAState-s where there is a State boundary:
+  // that is: two consecutive BBs have different RA State
+  BinaryFunction::iterator PrevBB;
+  bool FirstIter = true;
+  for (auto BB = BF.begin(); BB != BF.end(); ++BB) {
+    if (!FirstIter) {
+      if ((PrevBB->RAState == BinaryBasicBlock::RAStateEnum::Signed &&
+           (*BB).RAState == BinaryBasicBlock::RAStateEnum::Unsigned &&
+           !BBhasAUTH(BC, &(*PrevBB))) ||
+          (PrevBB->RAState == BinaryBasicBlock::RAStateEnum::Signed &&
+           (*BB).RAState == BinaryBasicBlock::RAStateEnum::Signed &&
+           BBhasAUTH(BC, &(*PrevBB)))) {
+        auto InstRevIter = PrevBB->getLastNonPseudo();
+        MCInst LastNonPseudo = *InstRevIter;
+        auto InstIter = InstRevIter.base();
+        BF.addCFIInstruction(&(*PrevBB), InstIter,
+                             MCCFIInstruction::createNegateRAState(nullptr));
+      }
+    } else {
+      FirstIter = false;
+    }
+    PrevBB = BB;
+  }
+}
+
+void InsertNegateRAState::explore_call_graph(BinaryContext &BC,
+                                             BinaryBasicBlock *BB) {
+  std::stack<BinaryBasicBlock *> SignedStack;
+  std::stack<BinaryBasicBlock *> UnsignedStack;
+
+  // start according to the first BB
+  if (BBhasSIGN(BC, BB)) {
+    SignedStack.push(BB);
+    process_signed_BB(BC, BB, &SignedStack, &UnsignedStack);
+  } else {
+    UnsignedStack.push(BB);
+    process_unsigned_BB(BC, BB, &SignedStack, &UnsignedStack);
+  }
+
+  while (!(SignedStack.empty() && UnsignedStack.empty())) {
+    if (!SignedStack.empty()) {
+      BB = SignedStack.top();
+      SignedStack.pop();
+      process_signed_BB(BC, BB, &SignedStack, &UnsignedStack);
+    } else if (!UnsignedStack.empty()) {
+      BB = UnsignedStack.top();
+      UnsignedStack.pop();
+      process_unsigned_BB(BC, BB, &SignedStack, &UnsignedStack);
+    }
+  }
+}
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paschalis-mpeis wrote:

nit: new line here

https://github.com/llvm/llvm-project/pull/117578