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#include "KernelCacheController.h"
#include "MachOProcessor.h"
using namespace BinaryNinja;
using namespace BinaryNinja::KC;
typedef uint64_t ViewId;
std::shared_mutex GlobalControllersMutex;
std::map<ViewId, KCRef<KernelCacheController>>& GlobalControllers()
{
static std::map<ViewId, KCRef<KernelCacheController>> g_controllers = {};
return g_controllers;
}
ViewId GetViewIdFromFileMetadata(const FileMetadata& file)
{
// Currently the view id is just the views session id.
// NOTE: If we want more than one shared cache controller per view we would need to make this more unique.
return file.GetSessionId();
}
void DeleteController(const FileMetadata& file)
{
const auto id = GetViewIdFromFileMetadata(file);
std::unique_lock<std::shared_mutex> lock(GlobalControllersMutex);
auto& controllers = GlobalControllers();
if (auto it = controllers.find(id); it != controllers.end())
{
auto controller = it->second;
// Someone is still holding the controller, lets warn about this.
// 2 is expected here because we have one held in `controllers` and one held by `controller`.
if (controller->m_refs > 2)
LogWarnF("Deleting KernelCacheController for view {:#x}, but there are still {} references", id,
controller->m_refs.load());
controllers.erase(it);
LogDebugF("Deleted KernelCacheController for view {:?}", file.GetFilename());
}
}
void RegisterKernelCacheControllerDestructor()
{
BNObjectDestructionCallbacks callbacks = {};
callbacks.destructFileMetadata = [](void* ctx, BNFileMetadata* obj) -> void {
const auto file = FileMetadata(obj);
DeleteController(file);
};
BNRegisterObjectDestructionCallbacks(&callbacks);
}
KernelCacheController::KernelCacheController(KernelCache&& cache, Ref<Logger> logger) : m_cache(std::move(cache))
{
INIT_KC_API_OBJECT();
m_logger = std::move(logger);
m_loadedImages = {};
m_regionFilter = std::regex(".*LINKEDIT.*");
}
KCRef<KernelCacheController> KernelCacheController::Initialize(BinaryView& view, KernelCache&& cache)
{
auto id = GetViewIdFromFileMetadata(*view.GetFile());
std::unique_lock<std::shared_mutex> lock(GlobalControllersMutex);
auto logger = new Logger("KernelCache.Controller", view.GetFile()->GetSessionId());
KCRef<KernelCacheController> controller = new KernelCacheController(std::move(cache), logger);
// Pull the settings from the view.
if (Ref<Settings> settings = view.GetLoadSettings(KC_VIEW_NAME))
{
if (settings->Contains("loader.kc.regionFilter"))
controller->m_regionFilter = std::regex(settings->Get<std::string>("loader.kc.regionFilter", &view));
}
// TODO: Support old shared cache metadata
// TODO: Not strictly necessary as the user has already loaded the information into the database, this would just
// TODO: prevent incidental extra work from being done when loading a region or image.
// const uint64_t oldStateCount = view.GetUIntMetadata(OLD_METADATA_KEY_COUNT);
// Check the view auto metadata for shared cache information.
// This effectively restores the state of the opened database to when it was last saved.
// NOTE: We store on the parent view because hilariously, the metadata is not present until after view init.
if (auto loadedImageMetadata = view.GetParentView()->QueryMetadata("KernelCacheLoadedImages"))
{
auto loadedImageList = loadedImageMetadata->GetArray();
for (const auto & imageAddrMeta : loadedImageList)
{
auto imageAddr = imageAddrMeta->GetUnsignedInteger();
controller->m_loadedImages.insert(imageAddr);
}
}
GlobalControllers().insert({id, controller});
return controller;
}
KCRef<KernelCacheController> KernelCacheController::FromView(const BinaryView& view)
{
auto id = GetViewIdFromFileMetadata(*view.GetFile());
std::shared_lock<std::shared_mutex> lock(GlobalControllersMutex);
auto& dscViews = GlobalControllers();
auto dscView = dscViews.find(id);
if (dscView == dscViews.end())
return nullptr;
return dscView->second;
}
bool KernelCacheController::ApplyImage(BinaryView& view, const CacheImage& image)
{
// Load all regions of an image and mark the image as loaded.
// NOTE: The regions lock m_loadMutex themselves, so we do not hold it up here.
bool loadedRegion = false;
BNRelocationInfo reloc;
memset(&reloc, 0, sizeof(BNRelocationInfo));
reloc.type = StandardRelocationType;
reloc.size = 8;
reloc.nativeType = BINARYNINJA_MANUAL_RELOCATION;
// We check for a valid offset as we apply auto segments and re-call this function on view init
if (!view.IsValidOffset(image.headerVirtualAddress))
{
loadedRegion = true;
for (const auto& segment : image.header->segments)
{
auto flags = SegmentFlagsFromMachOProtections(segment.initprot, segment.maxprot);
view.AddAutoSegment(segment.vmaddr, segment.vmsize, segment.fileoff, segment.filesize, flags);
auto relocations = m_cache.GetRelocations();
auto begin = std::lower_bound(relocations.begin(), relocations.end(), segment.vmaddr,
[](const std::pair<uint64_t, uint64_t>& reloc, uint64_t addr) {
return reloc.first < addr;
});
auto arch = view.GetDefaultArchitecture();
// Process relocations until the VM address is beyond our region
for (auto it = begin; it != relocations.end() && it->first < segment.vmaddr + segment.vmsize; ++it) {
reloc.address = it->first;
view.DefineRelocation(arch, reloc, it->second, reloc.address);
}
}
}
view.FinalizeNewSegments();
// The ApplyRegionAtAddress no longer holds the lock, we can take it now.
std::unique_lock<std::shared_mutex> lock(m_loadMutex);
// If there was no loaded regions than we just want to forgo loading the image.
// We also skip if we already loaded the image itself. We do this after loading regions
// as we regions have their own check.
// On view init, we exit here as we just need to re-add the segments and relocations.
if (!loadedRegion || m_loadedImages.find(image.headerVirtualAddress) != m_loadedImages.end())
return false;
if (image.headerVirtualAddress)
{
// Header information is applied to the view here, such as sections.
auto machoProcessor = KernelCacheMachOProcessor(&view);
// Adding a user section will mark all functions for updates unless we disable this.
// Because images are known separate compilation units, we have a real reason to make sure we don't mark all previously
// analyzed functions as updated.
auto prevDisabledState = view.GetFunctionAnalysisUpdateDisabled();
view.SetFunctionAnalysisUpdateDisabled(true);
machoProcessor.ApplyHeader(GetCache(), *image.header);
view.SetFunctionAnalysisUpdateDisabled(prevDisabledState);
}
m_loadedImages.insert(image.headerVirtualAddress);
m_logger->LogInfoF("Loaded image: '{}'", image.path);
// TODO: This needs to be done in a "database save" callback.
// NOTE: We store on the parent view because hilariously, the view metadata is not available in view init.
std::vector<uint64_t> loadedImages;
loadedImages.reserve(m_loadedImages.size());
// Store the loaded images in the metadata.
for (const uint64_t& addr : m_loadedImages)
{
loadedImages.push_back(addr);
}
view.GetParentView()->StoreMetadata("KernelCacheLoadedImages", new Metadata(loadedImages));
// TODO: Partial failure state (i.e. 2 regions loaded, one failed)
return true;
}
bool KernelCacheController::IsImageLoaded(const CacheImage& image)
{
std::shared_lock<std::shared_mutex> lock(m_loadMutex);
return std::any_of(m_loadedImages.begin(), m_loadedImages.end(), [&](const auto& loadedImage) {
return loadedImage == image.headerVirtualAddress;
});
}
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