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#include "PeiResolver.h"
bool PeiResolver::resolvePeiIdt()
{
string archName = m_view->GetDefaultArchitecture()->GetName();
string intrinsicName;
if (archName == "x86")
intrinsicName = "IDTR32";
else
intrinsicName = "IDTR64";
auto refs = m_view->GetCodeReferencesForType(QualifiedName(intrinsicName));
for (auto ref : refs) {
if (m_task->IsCancelled())
return false;
auto mlil = ref.func->GetMediumLevelIL();
auto instrIdx = mlil->GetInstructionStart(m_view->GetDefaultArchitecture(), ref.addr);
auto instr = mlil->GetInstruction(instrIdx);
auto hlil = ref.func->GetHighLevelIL();
auto hlils = HighLevelILExprsAt(ref.func, m_view->GetDefaultArchitecture(), ref.addr);
for (auto expr : hlils) {
if (expr.operation != HLIL_INTRINSIC ||
expr.GetParent().operation != HLIL_ASSIGN ||
expr.GetParent().GetDestExpr<HLIL_ASSIGN>().operation != HLIL_STRUCT_FIELD ||
expr.GetParent().GetDestExpr<HLIL_ASSIGN>().GetSourceExpr<HLIL_STRUCT_FIELD>().operation != HLIL_VAR)
continue;
auto var = expr.GetParent().GetDestExpr<HLIL_ASSIGN>().GetSourceExpr<HLIL_STRUCT_FIELD>().GetVariable();
ref.func->CreateUserVariable(var, m_view->GetTypeByName(QualifiedName(intrinsicName)), intrinsicName);
}
if (instr.operation == MLIL_INTRINSIC) {
// binja doesn't do type propagation on intrinsic instructions
auto output_params = instr.GetOutputVariables<MLIL_INTRINSIC>();
if (output_params.size() < 1)
continue;
ref.func->CreateUserVariable(output_params[0],
m_view->GetTypeByName(QualifiedName(intrinsicName)),
intrinsicName);
}
m_view->UpdateAnalysisAndWait();
}
// TODO There is an issue related to structure's type propagation, binja doesn't propagate indirect structure access properly
// here is a temporary fix, should be removed after vector35/binaryninja/#749 got fixed
refs = m_view->GetCodeReferencesForType(QualifiedName("EFI_PEI_SERVICES"));
for (auto ref : refs) {
if (m_task->IsCancelled())
return false;
auto mlil = ref.func->GetMediumLevelIL();
auto instrIdx = mlil->GetInstructionStart(m_view->GetDefaultArchitecture(), ref.addr);
auto instr = mlil->GetInstruction(instrIdx);
if (instr.operation != MLIL_SET_VAR)
continue;
if (instr.GetSourceExpr<MLIL_SET_VAR>().operation != MLIL_LOAD_STRUCT)
continue;
ref.func->CreateUserVariable(instr.GetDestVariable<MLIL_SET_VAR>(),
mlil->GetExprType(instr.GetSourceExpr<MLIL_SET_VAR>()).GetValue(),
nonConflictingLocalName(ref.func, "EfiPeiServices"));
m_view->UpdateAnalysisAndWait();
}
return true;
}
bool PeiResolver::resolvePeiMrc()
{
auto funcs = m_view->GetAnalysisFunctionList();
for (auto func : funcs) {
if (m_task->IsCancelled())
return false;
auto mlil = func->GetMediumLevelIL();
auto blocks = mlil->GetBasicBlocks();
for (auto block : blocks) {
for (size_t i = block->GetStart(); i < block->GetEnd(); i++) {
auto instr = mlil->GetInstruction(i);
if (instr.operation != MLIL_INTRINSIC)
continue;
uint32_t intrinsicIdx = instr.GetIntrinsic<MLIL_INTRINSIC>();
if (m_view->GetDefaultArchitecture()->GetIntrinsicName(intrinsicIdx) != "Coproc_GetOneWord")
continue;
auto intrinsicParams = instr.GetParameterExprs<MLIL_INTRINSIC>();
if (intrinsicParams.size() != 5)
continue;
bool found = true;
const int value[5] = { 0xf, 0x0, 0xd, 0x0, 0x2 };
for (int j = 0; j < 5; j++) {
auto param = intrinsicParams[j];
if (param.operation != MLIL_CONST) {
found = false;
break;
}
if (param.GetConstant<MLIL_CONST>() != value[j]) {
found = false;
break;
}
}
if (!found)
continue;
// At this point, we can make sure this instruction fetches EFI_PEI_SERVICES
auto output = instr.GetOutputVariables();
if (output.size() > 0) {
auto pointerType = Type::PointerType(m_view->GetDefaultArchitecture(),
Type::PointerType(m_view->GetDefaultArchitecture(),
m_view->GetTypeByName(QualifiedName("EFI_PEI_SERVICES"))));
func->CreateUserVariable(output[0], pointerType, nonConflictingLocalName(func, "PeiServices"));
m_view->UpdateAnalysisAndWait();
}
}
}
}
return true;
}
bool PeiResolver::resolvePeiMrs()
{
// ideally we don't need this function, but since we don't support type propagation on intrinsic instructions
// we have to manually propagate it
auto refs = m_view->GetCodeReferencesForType(QualifiedName("EFI_PEI_SERVICES"));
for (auto ref : refs) {
if (m_task->IsCancelled())
return false;
auto mlil = ref.func->GetMediumLevelIL();
auto instrIdx = mlil->GetInstructionStart(m_view->GetDefaultArchitecture(), ref.addr);
auto instr = mlil->GetInstruction(instrIdx);
if (instr.operation == MLIL_INTRINSIC) {
auto params = instr.GetOutputVariables();
if (params.size() < 1)
continue;
auto pointerType = Type::PointerType(m_view->GetDefaultArchitecture(),
Type::PointerType(m_view->GetDefaultArchitecture(),
m_view->GetTypeByName(QualifiedName("EFI_PEI_SERVICES"))));
ref.func->CreateUserVariable(params[0],
pointerType,
nonConflictingLocalName(ref.func, "EfiPeiServices"));
m_view->UpdateAnalysisAndWait();
}
}
return true;
}
bool PeiResolver::resolvePlatformPointers()
{
string archName = m_view->GetDefaultArchitecture()->GetName();
string intrinsicTypeName;
if (archName == "x86" || archName == "x86-64") {
return resolvePeiIdt();
} else if (archName == "arm" || archName == "thumb2") {
return resolvePeiMrc();
} else if (archName == "aarch64") {
return resolvePeiMrs();
}
LogError("Not supported arch: %s", archName.c_str());
return false;
}
bool PeiResolver::resolvePeiDescriptors()
{
const string descriptorNames[2] = { "EFI_PEI_NOTIFY_DESCRIPTOR", "EFI_PEI_PPI_DESCRIPTOR" };
for (auto descriptor : descriptorNames) {
auto refs = m_view->GetCodeReferencesForType(QualifiedName(descriptor));
for (auto ref : refs) {
if (m_task->IsCancelled())
return false;
auto mlil = ref.func->GetMediumLevelIL();
auto instrIdx = mlil->GetInstructionStart(m_view->GetDefaultArchitecture(), ref.addr);
auto instr = mlil->GetInstruction(instrIdx);
if (instr.operation != MLIL_CALL && instr.operation != MLIL_TAILCALL)
continue;
auto destExpr = instr.GetDestExpr();
if (destExpr.operation != MLIL_LOAD_STRUCT)
continue;
// at this point this instruction is probably a call to LocatPpi, InstallPpi or NotifyPpi
if (!mlil->GetExprType(destExpr).GetValue()->IsPointer())
continue;
auto funcType = mlil->GetExprType(destExpr).GetValue()->GetChildType().GetValue();
auto params = funcType->GetParameters();
int targetParamIdx = -1;
for (int i = 0; i < params.size(); i++) {
auto param = params[i];
if (!param.type.GetValue()->IsPointer())
continue;
auto paramTypeName = param.type.GetValue()->GetChildType().GetValue()->GetTypeName().GetString();
if (paramTypeName.find(descriptor) != paramTypeName.npos) {
// this is the param
targetParamIdx = i;
break;
}
}
if (targetParamIdx < 0)
continue;
// Now we are confident that this position is a call that pass Descriptor as a parameter
defineTypeAtCallsite(ref.func, ref.addr, descriptor, targetParamIdx, true);
}
}
return true;
}
bool PeiResolver::resolvePeiServices()
{
auto refs = m_view->GetCodeReferencesForType(QualifiedName("EFI_PEI_SERVICES"));
for (auto ref : refs) {
if (m_task->IsCancelled())
return false;
auto func = ref.func;
auto mlil = func->GetMediumLevelIL();
if (!mlil)
continue;
auto mlilSsa = mlil->GetSSAForm();
size_t mlilIdx = mlil->GetInstructionStart(m_view->GetDefaultArchitecture(), ref.addr);
auto instr = mlilSsa->GetInstruction(mlil->GetSSAInstructionIndex(mlilIdx));
if (instr.operation == MLIL_CALL_SSA || instr.operation == MLIL_TAILCALL_SSA) {
auto dest = instr.GetDestExpr();
if (dest.operation != MLIL_LOAD_STRUCT_SSA)
continue;
auto offset = dest.GetOffset();
if (offset == 0x18 + m_width * 2) {
// LocatePpi
resolveGuidInterface(ref.func, ref.addr, 1, 4);
} else if (offset == 0x18 || offset == 0x18 + m_width || offset == 0x18 + m_width * 3) {
// InstallPpi, ReinstallPpi, NotifyPpi
}
}
}
return true;
}
bool PeiResolver::resolvePei()
{
if (!setModuleEntry(PEI))
return false;
if (!resolvePlatformPointers())
return false;
if (!resolvePeiDescriptors())
return false;
if (!resolvePeiServices())
return false;
return true;
}
PeiResolver::PeiResolver(Ref<BinaryView> view, Ref<BackgroundTask> task)
: Resolver(view, task)
{
initProtocolMapping();
setModuleEntry(PEI);
}
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