[llvm-branch-commits] [llvm] [BOLT] Gadget scanner: detect signing oracles (PR #134146)

[Kristof Beyls via llvm-branch-commits]

================
@@ -355,6 +389,46 @@ class SrcSafetyAnalysis {
     return Regs;
   }
 
+  // Returns all registers made trusted by this instruction.
+  SmallVector<MCPhysReg> getRegsMadeTrusted(const MCInst &Point,
+                                            const SrcState &Cur) const {
+    SmallVector<MCPhysReg> Regs;
+    const MCPhysReg NoReg = BC.MIB->getNoRegister();
+
+    // An authenticated pointer can be checked, or
+    MCPhysReg CheckedReg =
+        BC.MIB->getAuthCheckedReg(Point, /*MayOverwrite=*/false);
+    if (CheckedReg != NoReg && Cur.SafeToDerefRegs[CheckedReg])
+      Regs.push_back(CheckedReg);
+
+    if (CheckerSequenceInfo.contains(&Point)) {
+      MCPhysReg CheckedReg;
+      const MCInst *FirstCheckerInst;
+      std::tie(CheckedReg, FirstCheckerInst) = CheckerSequenceInfo.at(&Point);
+
+      // FirstCheckerInst should belong to the same basic block, meaning
+      // it was deterministically processed a few steps before this instruction.
+      const SrcState &StateBeforeChecker =
+          getStateBefore(*FirstCheckerInst).get();
----------------
kbeyls wrote:

Thanks, that all makes sense.

https://github.com/llvm/llvm-project/pull/134146