[X86] Add a Pass that builds a Condensed CFG for Load Value Injection (LVI) Gadgets

Adds a new data structure, ImmutableGraph, and uses RDF to find LVI gadgets and add them to a MachineGadgetGraph.

More specifically, a new X86 machine pass finds Load Value Injection (LVI) gadgets consisting of a load from memory (i.e., SOURCE), and any operation that may transmit the value loaded from memory over a covert channel, or use the value loaded from memory to determine a branch/call target (i.e., SINK).

Also adds a new target feature to X86: +lvi-load-hardening

The feature can be added via the clang CLI using -mlvi-hardening.

Differential Revision: https://reviews.llvm.org/D75936

1 files changed, 2 insertions, 0 deletions

diff --git a/llvm/lib/Target/X86/X86TargetMachine.cpp b/llvm/lib/Target/X86/X86TargetMachine.cpp
index e374b16e0e3..680a52b5438 100644
--- a/llvm/lib/Target/X86/X86TargetMachine.cpp
+++ b/llvm/lib/Target/X86/X86TargetMachine.cpp
@@ -82,6 +82,7 @@ extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeX86Target() {
   initializeX86SpeculativeLoadHardeningPassPass(PR);
   initializeX86FlagsCopyLoweringPassPass(PR);
   initializeX86CondBrFoldingPassPass(PR);
+  initializeX86LoadValueInjectionLoadHardeningPassPass(PR);
   initializeX86LoadValueInjectionRetHardeningPassPass(PR);
   initializeX86OptimizeLEAPassPass(PR);
 }
@@ -497,6 +498,7 @@ void X86PassConfig::addMachineSSAOptimization() {
 
 void X86PassConfig::addPostRegAlloc() {
   addPass(createX86FloatingPointStackifierPass());
+  addPass(createX86LoadValueInjectionLoadHardeningPass());
 }
 
 void X86PassConfig::addPreSched2() { addPass(createX86ExpandPseudoPass()); }