Merge branch '_xeroxz' into 'master'

testing a new method for dealing with the stack...

See merge request vmp2/vmdevirt!2

include/vmp_rtn.hpp

@@ -38,11 +38,12 @@ namespace vm
                             std::uintptr_t rtn_begin, std::vector< vm::instrs::code_block_t > vmp2_code_blocks );
 
         llvm_function_t *lift( void );
+
       private:
         llvm_context_t *llvm_ctx;
         llvm_module_t *llvm_module;
         llvm_function_t *llvm_fptr;
-        llvm_alloca_inst_t *flags;
+        llvm_alloca_inst_t *flags, *stack;
 
         vm::ctx_t *vm_ctx;
         std::uintptr_t rtn_begin;

src/lifters/pushvsp.cpp

@@ -5,6 +5,8 @@ namespace vm
     lifters_t::lifter_callback_t lifters_t::pushvsp =
         [ & ]( vm::vmp_rtn_t *rtn, const vm::instrs::code_block_t &vm_code_block,
                const vm::instrs::virt_instr_t &vinstr, llvm::IRBuilder<> *ir_builder ) {
-
+            auto sp = rtn->pop( 8 );
+            auto sp_ptr = ir_builder->CreateIntToPtr( sp, llvm::PointerType::get( ir_builder->getInt8Ty(), 0ull ) );
+            ir_builder->CreateStore( sp_ptr, rtn->stack );
         };
 }

src/vmp_rtn.cpp

@@ -13,6 +13,9 @@ namespace vm
         ir_builder = std::make_shared< llvm_irbuilder_t >( *llvm_ctx );
         ir_builder->SetInsertPoint( llvm_code_blocks[ 0 ].second );
         flags = ir_builder->CreateAlloca( ir_builder->getInt64Ty(), nullptr, "flags" );
+        stack = ir_builder->CreateAlloca( llvm::PointerType::get( ir_builder->getInt8Ty(), 0ull ), nullptr, "sp" );
+
+        ir_builder->CreateStore( llvm_fptr->getArg( 0 ), stack );
         create_virtual_registers();
     }
 
@@ -30,7 +33,7 @@ namespace vm
         // function has no arguments and returns void... maybe change this in the future as i learn
         // more and more LLVM...
         auto func_ty = llvm::FunctionType::get( llvm::Type::getVoidTy( *llvm_ctx ),
-                                                { llvm::PointerType::getInt64PtrTy( *llvm_ctx ) }, false );
+                                                { llvm::PointerType::getInt8PtrTy( *llvm_ctx ) }, false );
 
         // convert the rtn_begin address to a hex string and prepend "rtn_" to it...
         std::stringstream rtn_name;
@@ -38,7 +41,6 @@ namespace vm
         llvm_fptr = llvm::Function::Create( func_ty, llvm::GlobalValue::LinkageTypes::ExternalLinkage,
                                             rtn_name.str().c_str(), *llvm_module );
 
-        
         for ( const auto &vmp2_code_block : vmp2_code_blocks )
         {
             // create basic block name... block_xxxxxxxx format...
@@ -52,29 +54,34 @@ namespace vm
     void vmp_rtn_t::push( std::uint8_t num_bytes, llvm_value_t *val )
     {
         // sub rsp, num_bytes
-        auto rsp = llvm_fptr->getArg( 0 );
-        auto rsp_i64 = ir_builder->CreatePtrToInt( rsp, ir_builder->getInt64Ty() );
+        auto rsp_addr = ir_builder->CreateLoad( stack );
+        auto rsp_i64 = ir_builder->CreatePtrToInt( rsp_addr, ir_builder->getInt64Ty() );
         auto sub_rsp_val = ir_builder->CreateSub( rsp_i64, ir_builder->getInt64( num_bytes ) );
-        ir_builder->CreateStore( sub_rsp_val, rsp );
+        ir_builder->CreateStore(
+            ir_builder->CreateIntToPtr( sub_rsp_val, llvm::PointerType::get( ir_builder->getInt8Ty(), 0ull ) ), stack );
 
         // mov [rsp], val
+        rsp_addr = ir_builder->CreateLoad( stack );
         auto rsp_cast_ptr = ir_builder->CreatePointerCast(
-            rsp, llvm::PointerType::get( llvm::IntegerType::get( *llvm_ctx, num_bytes * 8 ), false ) );
+            rsp_addr, llvm::PointerType::get( llvm::IntegerType::get( *llvm_ctx, num_bytes * 8 ), false ) );
         ir_builder->CreateStore( val, rsp_cast_ptr );
     }
 
     llvm_value_t *vmp_rtn_t::pop( std::uint8_t num_bytes )
     {
         // mov rax, [rsp]
-        auto rsp = llvm_fptr->getArg( 0 );
+        auto rsp_addr = ir_builder->CreateLoad( stack );
         auto rsp_cast_ptr = ir_builder->CreatePointerCast(
-            rsp, llvm::PointerType::get( llvm::IntegerType::get( *llvm_ctx, num_bytes * 8 ), false ) );
+            rsp_addr, llvm::PointerType::get( llvm::IntegerType::get( *llvm_ctx, num_bytes * 8 ), false ) );
         auto pop_val = ir_builder->CreateLoad( rsp_cast_ptr );
 
         // add rsp, num_bytes
-        auto rsp_i64 = ir_builder->CreatePtrToInt( rsp, ir_builder->getInt64Ty() );
+        auto rsp_i64 = ir_builder->CreatePtrToInt( rsp_addr, ir_builder->getInt64Ty() );
         auto sub_rsp_val = ir_builder->CreateAdd( rsp_i64, ir_builder->getInt64( num_bytes ) );
-        ir_builder->CreateStore( sub_rsp_val, rsp );
+        auto sub_rsp_val_ptr =
+            ir_builder->CreateIntToPtr( sub_rsp_val, llvm::PointerType::get( ir_builder->getInt8Ty(), 0ull ) );
+
+        ir_builder->CreateStore( sub_rsp_val_ptr, stack );
         return pop_val;
     }