crashinfo.cpp

// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

#include "createdump.h"

typedef BOOL (PALAPI_NOEXPORT *PFN_DLLMAIN)(HINSTANCE, DWORD, LPVOID);      /* entry point of module */
typedef HINSTANCE (PALAPI_NOEXPORT *PFN_REGISTER_MODULE)(LPCSTR);           /* used to create the HINSTANCE for above DLLMain entry point */

// This is for the PAL_VirtualUnwindOutOfProc read memory adapter.
CrashInfo* g_crashInfo;

// This is the NativeAOT DotNetRuntimeDebugHeader signature
uint8_t g_debugHeaderCookie[4] = { 0x44, 0x4E, 0x44, 0x48 };

static bool ModuleInfoCompare(const ModuleInfo* lhs, const ModuleInfo* rhs) { return lhs->BaseAddress() < rhs->BaseAddress(); }

CrashInfo::CrashInfo(const CreateDumpOptions& options) :
    m_ref(1),
    m_pid(options.Pid),
    m_ppid(-1),
    m_dacModule(nullptr),
    m_pClrDataEnumRegions(nullptr),
    m_pClrDataProcess(nullptr),
    m_appModel(options.AppModel),
    m_gatherFrames(options.CrashReport),
    m_crashThread(options.CrashThread),
    m_signal(options.Signal),
    m_exceptionRecord(options.ExceptionRecord),
    m_moduleInfos(&ModuleInfoCompare),
    m_mainModule(nullptr),
    m_cbModuleMappings(0),
    m_dataTargetPagesAdded(0),
    m_enumMemoryPagesAdded(0)
{
    g_crashInfo = this;
    m_runtimeBaseAddress = 0;
#ifdef __APPLE__
    m_task = 0;
#else
    m_auxvValues.fill(0);
    m_fdMem = -1;
#endif
    memset(&m_siginfo, 0, sizeof(m_siginfo));
    m_siginfo.si_signo = options.Signal;
    m_siginfo.si_code = options.SignalCode;
    m_siginfo.si_errno = options.SignalErrno;
    m_siginfo.si_addr = (void*)options.SignalAddress;
}

CrashInfo::~CrashInfo()
{
    // Clean up the threads
    for (ThreadInfo* thread : m_threads)
    {
        delete thread;
    }
    m_threads.clear();

    // Clean up the modules
    for (ModuleInfo* module : m_moduleInfos)
    {
        delete module;
    }
    m_moduleInfos.clear();

    // Clean up DAC interfaces
    if (m_pClrDataEnumRegions != nullptr)
    {
        m_pClrDataEnumRegions->Release();
    }
    if (m_pClrDataProcess != nullptr)
    {
        m_pClrDataProcess->Release();
    }
    // Unload DAC module
    if (m_dacModule != nullptr)
    {
        dlclose(m_dacModule);
        m_dacModule = nullptr;
    }
#ifdef __APPLE__
    if (m_task != 0)
    {
        kern_return_t result = ::mach_port_deallocate(mach_task_self(), m_task);
        if (result != KERN_SUCCESS)
        {
            printf_error("Internal error: mach_port_deallocate FAILED %s (%x)\n", mach_error_string(result), result);
        }
    }
#endif
}

STDMETHODIMP
CrashInfo::QueryInterface(
    ___in REFIID InterfaceId,
    ___out PVOID* Interface)
{
    if (InterfaceId == IID_IUnknown ||
        InterfaceId == IID_ICLRDataEnumMemoryRegionsCallback)
    {
        *Interface = (ICLRDataEnumMemoryRegionsCallback*)this;
        AddRef();
        return S_OK;
    }
    else if (InterfaceId == IID_ICLRDataLoggingCallback)
    {
        *Interface = (ICLRDataLoggingCallback*)this;
        AddRef();
        return S_OK;
    }
    else
    {
        *Interface = nullptr;
        return E_NOINTERFACE;
    }
}

STDMETHODIMP_(ULONG)
CrashInfo::AddRef()
{
    LONG ref = InterlockedIncrement(&m_ref);
    return ref;
}

STDMETHODIMP_(ULONG)
CrashInfo::Release()
{
    LONG ref = InterlockedDecrement(&m_ref);
    if (ref == 0)
    {
        delete this;
    }
    return ref;
}

HRESULT STDMETHODCALLTYPE
CrashInfo::EnumMemoryRegion(
    /* [in] */ CLRDATA_ADDRESS address,
    /* [in] */ ULONG32 size)
{
    m_enumMemoryPagesAdded += InsertMemoryRegion((ULONG_PTR)address, size);
    return S_OK;
}

HRESULT STDMETHODCALLTYPE
CrashInfo::LogMessage(
    /* [in] */ LPCSTR message)
{
    Trace("%s", message);
    return S_OK;
}

//
// Gather all the necessary crash dump info.
//
bool
CrashInfo::GatherCrashInfo(DumpType dumpType)
{
    // Get the info about the threads (registers, etc.)
    for (ThreadInfo* thread : m_threads)
    {
        if (!thread->Initialize())
        {
            return false;
        }
    }
#ifdef __APPLE__
    if (!EnumerateMemoryRegions())
    {
        return false;
    }
#else
    // Get the auxv data
    if (!GetAuxvEntries())
    {
        return false;
    }
    // Gather all the module memory mappings (from /dev/$pid/maps)
    if (!EnumerateMemoryRegions())
    {
        return false;
    }
    // Get shared module debug info
    if (!GetDSOInfo())
    {
        return false;
    }
#endif
    // Load and initialize DAC interfaces
    if (!InitializeDAC(dumpType))
    {
        return false;
    }
    // Enumerate all the managed modules. On MacOS only the native modules have been added
    // to the module mapping list at this point and adds the managed modules. This needs to
    // be done before the other mappings is initialized.
    if (!EnumerateManagedModules())
    {
        return false;
    }
    // Add the special (fake) memory region for the special diagnostics info
    MemoryRegion special(PF_R, SpecialDiagInfoAddress, SpecialDiagInfoAddress + SpecialDiagInfoSize);
    m_memoryRegions.insert(special);
#ifdef __APPLE__
    InitializeOtherMappings();
#endif
    if (!UnwindAllThreads())
    {
        return false;
    }
    if (g_diagnosticsVerbose)
    {
        TRACE("Module addresses:\n");
        for (const MemoryRegion& region : m_moduleAddresses)
        {
            region.Trace();
        }
    }
    // If full memory dump, include everything regardless of permissions
    if (dumpType == DumpType::Full)
    {
        for (const MemoryRegion& region : m_moduleMappings)
        {
            InsertMemoryRegion(region);
        }
        for (const MemoryRegion& region : m_otherMappings)
        {
            // Don't add uncommitted pages to the full dump
            if ((region.Permissions() & (PF_R | PF_W | PF_X)) != 0)
            {
                InsertMemoryRegion(region);
            }
        }
    }
    else
    {
        // Add all the heap read/write memory regions (m_otherMappings contains the heaps). On Alpine
        // the heap regions are marked RWX instead of just RW.
        if (dumpType == DumpType::Heap)
        {
            for (const MemoryRegion& region : m_otherMappings)
            {
                uint32_t permissions = region.Permissions();
#ifdef __APPLE__
                if (permissions == (PF_R | PF_W))
#else
                if (permissions == (PF_R | PF_W) || permissions == (PF_R | PF_W | PF_X))
#endif
                {
                    InsertMemoryRegion(region);
                }
            }
        }
        // Add the thread's stack and some code memory to core
        for (ThreadInfo* thread : m_threads)
        {
            // Add the thread's stack
            thread->GetThreadStack();
        }
    }
    return true;
}

static const char*
GetHResultString(HRESULT hr)
{
    switch (hr)
    {
    case E_FAIL:
        return "The operation has failed";
    case E_INVALIDARG:
        return "Invalid argument";
    case E_OUTOFMEMORY:
        return "Out of memory";
    case CORDBG_E_INCOMPATIBLE_PLATFORMS:
        return "The operation failed because debuggee and debugger are on incompatible platforms";
    case CORDBG_E_MISSING_DEBUGGER_EXPORTS:
        return "The debuggee memory space does not have the expected debugging export table";
    case CORDBG_E_UNSUPPORTED:
        return "The specified action is unsupported by this version of the runtime";
    }
    return "";
}

//
// Enumerate all the memory regions using the DAC memory region support given a minidump type
//
bool
CrashInfo::InitializeDAC(DumpType dumpType)
{
    // Don't attempt to load the DAC if the app model doesn't support it by default. The default for single-file is
    // a full dump, but if the dump type requested is a mini, triage or heap and the DAC is next to the single-file
    // application the core dump will be generated. For NativeAOT, there is currently no DAC available so never
    // attempt to load it.
    if ((dumpType == DumpType::Full && m_appModel == AppModelType::SingleFile) || m_appModel == AppModelType::NativeAOT)
    {
        return true;
    }
    // Can't load the DAC if the runtime wasn't found
    if (m_coreclrPath.empty())
    {
        printf_error("InitializeDAC: coreclr not found; not using DAC\n");
        return true;
    }
    ReleaseHolder<DumpDataTarget> dataTarget = new DumpDataTarget(*this);
    PFN_CLRDataCreateInstance pfnCLRDataCreateInstance = nullptr;
    PFN_DLLMAIN pfnDllMain = nullptr;
    bool result = false;
    HRESULT hr = S_OK;

    // We assume that the DAC is in the same location as the libcoreclr.so module
    std::string dacPath;
    dacPath.append(m_coreclrPath);
    dacPath.append(MAKEDLLNAME_A("mscordaccore"));

    // Load and initialize the DAC. We don't use the LoadLibraryA here because the PAL may not be
    // initialized properly in the forked process for the statically linked single-file scenario.
    m_dacModule = dlopen(dacPath.c_str(), RTLD_LAZY);
    if (m_dacModule == nullptr)
    {
        printf_error("InitializeDAC: dlopen(%s) FAILED %s\n", dacPath.c_str(), dlerror());
        goto exit;
    }
    pfnDllMain = (PFN_DLLMAIN)dlsym(m_dacModule, "DllMain");
    if (pfnDllMain != nullptr)
    {
        PFN_REGISTER_MODULE registerModule = (PFN_REGISTER_MODULE)dlsym(m_dacModule, "PAL_RegisterModule");
        if (registerModule == nullptr)
        {
            printf_error("InitializeDAC: PAL_RegisterModule FAILED\n");
            goto exit;
        }
        HINSTANCE hModule = registerModule(dacPath.c_str());
        if (!pfnDllMain(hModule, DLL_PROCESS_ATTACH, nullptr))
        {
            printf_error("InitializeDAC: DllMain(DLL_PROCESS_ATTACH) FAILED\n");
            goto exit;
        }
    }
    pfnCLRDataCreateInstance = (PFN_CLRDataCreateInstance)dlsym(m_dacModule, "CLRDataCreateInstance");
    if (pfnCLRDataCreateInstance == nullptr)
    {
        printf_error("InitializeDAC: GetProcAddress(CLRDataCreateInstance) FAILED %s\n", dlerror());
        goto exit;
    }
    hr = pfnCLRDataCreateInstance(__uuidof(ICLRDataEnumMemoryRegions), dataTarget, (void**)&m_pClrDataEnumRegions);
    if (FAILED(hr))
    {
        printf_error("InitializeDAC: CLRDataCreateInstance(ICLRDataEnumMemoryRegions) FAILED %s (%08x)\n", GetHResultString(hr), hr);
        goto exit;
    }
    hr = pfnCLRDataCreateInstance(__uuidof(IXCLRDataProcess), dataTarget, (void**)&m_pClrDataProcess);
    if (FAILED(hr))
    {
        printf_error("InitializeDAC: CLRDataCreateInstance(IXCLRDataProcess) FAILED %s (%08x)\n", GetHResultString(hr), hr);
        goto exit;
    }
    result = true;
exit:
    return result;
}

//
// Enumerate all the memory regions using the DAC memory region support given a minidump type
//
bool
CrashInfo::EnumerateMemoryRegionsWithDAC(DumpType dumpType)
{
    if (m_pClrDataEnumRegions != nullptr && dumpType != DumpType::Full)
    {
        TRACE("EnumerateMemoryRegionsWithDAC: Memory enumeration STARTED (%d %d)\n", m_enumMemoryPagesAdded, m_dataTargetPagesAdded);

        // CLRDATA_ENUM_MEM_HEAP2 skips the expensive (in both time and memory usage) enumeration of the
        // low level data structures and adds all the loader allocator heaps instead. The older 'DbgEnableFastHeapDumps'
        // env var didn't generate a complete enough heap dump on Linux and this new path does.
        CLRDataEnumMemoryFlags flags = CLRDATA_ENUM_MEM_HEAP2;
        MINIDUMP_TYPE minidumpType = GetMiniDumpType(dumpType);
        if (dumpType == DumpType::Heap)
        {
            // This is the old fast heap env var for backwards compatibility for VS4Mac.
            CLRConfigNoCache fastHeapDumps = CLRConfigNoCache::Get("DbgEnableFastHeapDumps", /*noprefix*/ false, &getenv);
            DWORD val = 0;
            if (fastHeapDumps.IsSet() && fastHeapDumps.TryAsInteger(10, val) && val == 1)
            {
                // Since on MacOS all the RW regions will be added for heap dumps by createdump, the
                // only thing differentiating a MiniDumpNormal and a MiniDumpWithPrivateReadWriteMemory
                // is that the later uses the EnumMemoryRegions APIs. This is kind of expensive on larger
                // applications (4 minutes, or even more), and this should already be in RW pages. Change
                // the dump type to the faster normal one. This one already ensures necessary DAC globals,
                // etc. without the costly assembly, module, class, type runtime data structures enumeration.
                minidumpType = MiniDumpNormal;
                flags = CLRDATA_ENUM_MEM_DEFAULT;
            }
            // This env var allows the CLRDATA_ENUM_MEM_HEAP2 fast path to be opt-ed out
            fastHeapDumps = CLRConfigNoCache::Get("EnableFastHeapDumps", /*noprefix*/ false, &getenv);
            if (fastHeapDumps.IsSet() && fastHeapDumps.TryAsInteger(10, val) && val == 0)
            {
                flags = CLRDATA_ENUM_MEM_DEFAULT;
            }
        }
        // Calls CrashInfo::EnumMemoryRegion for each memory region found by the DAC
        HRESULT hr = m_pClrDataEnumRegions->EnumMemoryRegions(this, minidumpType, flags);
        if (FAILED(hr))
        {
            printf_error("EnumMemoryRegions FAILED %s (%08x)\n", GetHResultString(hr), hr);
            return false;
        }
        TRACE("EnumerateMemoryRegionsWithDAC: Memory enumeration FINISHED (%d %d)\n", m_enumMemoryPagesAdded, m_dataTargetPagesAdded);
    }
    return true;
}

//
// Enumerate all the managed modules and replace the module mapping with the module name found.
//
bool
CrashInfo::EnumerateManagedModules()
{
    CLRDATA_ENUM enumModules = 0;
    HRESULT hr = S_OK;

    if (m_pClrDataProcess != nullptr)
    {
        TRACE("EnumerateManagedModules: Module enumeration STARTED (%d)\n", m_dataTargetPagesAdded);

        if (FAILED(hr = m_pClrDataProcess->StartEnumModules(&enumModules))) {
            printf_error("StartEnumModules FAILED %s (%08x)\n", GetHResultString(hr), hr);
            return false;
        }

        while (true)
        {
            ReleaseHolder<IXCLRDataModule> pClrDataModule;
            if ((hr = m_pClrDataProcess->EnumModule(&enumModules, &pClrDataModule)) != S_OK) {
                break;
            }

            // Skip any dynamic modules. The Request call below on some DACs crashes on dynamic modules.
            ULONG32 flags;
            if ((hr = pClrDataModule->GetFlags(&flags)) != S_OK) {
                TRACE("MODULE: GetFlags FAILED %08x\n", hr);
                continue;
            }
            if (flags & CLRDATA_MODULE_IS_DYNAMIC) {
                TRACE("MODULE: Skipping dynamic module\n");
                continue;
            }

            DacpGetModuleData moduleData;
            if (SUCCEEDED(hr = moduleData.Request(pClrDataModule.GetPtr())))
            {
                TRACE("MODULE: %" PRIA PRIx64 " dyn %d inmem %d file %d pe %" PRIA PRIx64 " pdb %" PRIA PRIx64, (uint64_t)moduleData.LoadedPEAddress, moduleData.IsDynamic,
                    moduleData.IsInMemory, moduleData.IsFileLayout, (uint64_t)moduleData.PEAssembly, (uint64_t)moduleData.InMemoryPdbAddress);

                if (!moduleData.IsDynamic && moduleData.LoadedPEAddress != 0)
                {
                    ArrayHolder<WCHAR> wszUnicodeName = new WCHAR[MAX_LONGPATH + 1];
                    if (SUCCEEDED(hr = pClrDataModule->GetFileName(MAX_LONGPATH, nullptr, wszUnicodeName)))
                    {
                        std::string moduleName = ConvertString(wszUnicodeName.GetPtr());

                        // Change the module mapping name
                        AddOrReplaceModuleMapping(moduleData.LoadedPEAddress, moduleData.LoadedPESize, moduleName);

                        // Add managed module info
                        AddModuleInfo(true, moduleData.LoadedPEAddress, pClrDataModule, moduleName);
                    }
                    else {
                        TRACE("\nModule.GetFileName FAILED %08x\n", hr);
                    }
                }
                else {
                    TRACE("\n");
                }
            }
            else {
                TRACE("moduleData.Request FAILED %08x\n", hr);
            }
        }

        if (enumModules != 0) {
            m_pClrDataProcess->EndEnumModules(enumModules);
        }
        TRACE("EnumerateManagedModules: Module enumeration FINISHED (%d) ModuleMappings %06llx\n", m_dataTargetPagesAdded, m_cbModuleMappings / PAGE_SIZE);
    }
    return true;
}

//
// Unwind all the native threads to ensure that the dwarf unwind info is added to the core dump.
//
bool
CrashInfo::UnwindAllThreads()
{
    // Don't unwind any threads if Native AOT since there isn't a DAC to get the remote
    // unwinder support and they are full dumps.
    if (m_appModel != AppModelType::NativeAOT)
    {
        TRACE("UnwindAllThreads: STARTED (%d)\n", m_dataTargetPagesAdded);
        ReleaseHolder<ISOSDacInterface> pSos = nullptr;
        if (m_pClrDataProcess != nullptr) {
            m_pClrDataProcess->QueryInterface(__uuidof(ISOSDacInterface), (void**)&pSos);
        }
        // For each native and managed thread
        for (ThreadInfo* thread : m_threads)
        {
            if (!thread->UnwindThread(m_pClrDataProcess, pSos)) {
                return false;
            }
        }
        TRACE("UnwindAllThreads: FINISHED (%d)\n", m_dataTargetPagesAdded);
    }
    return true;
}

//
// Replace an existing module mapping with one with a different name.
//
void
CrashInfo::AddOrReplaceModuleMapping(CLRDATA_ADDRESS baseAddress, ULONG64 size, const std::string& name)
{
    // Round to page boundary (single-file managed assemblies are not page aligned)
    ULONG_PTR start = ((ULONG_PTR)baseAddress) & PAGE_MASK;
    assert(start > 0);

    // Round up to page boundary
    ULONG_PTR end = ((baseAddress + size) + (PAGE_SIZE - 1)) & PAGE_MASK;
    assert(end > 0);

    uint32_t flags = GetMemoryRegionFlags((ULONG_PTR)baseAddress);

    // Make sure that the page containing the PE header for the managed asseblies is in the dump
    // especially on MacOS where they are added artificially.
    MemoryRegion header(flags, start, start + PAGE_SIZE);
    InsertMemoryRegion(header);

    // Add or change the module mapping for this PE image. The managed assembly images may already
    // be in the module mappings list but they may not have the full assembly name (like in .NET 2.0
    // they have the name "/dev/zero"). On MacOS, the managed assembly modules have not been added.
    const auto& found = m_moduleMappings.find(header);
    if (found == m_moduleMappings.end())
    {
        // On MacOS the assemblies are always added.
        MemoryRegion newRegion(flags, start, end, 0, name);
        m_moduleMappings.insert(newRegion);
        m_cbModuleMappings += newRegion.Size();

        if (g_diagnostics) {
            newRegion.Trace("MODULE: ADD ");
        }
    }
    else if (found->FileName().compare(name) != 0)
    {
        // Create the new memory region with the managed assembly name.
        MemoryRegion newRegion(*found, name);

        // Remove and cleanup the old one
        m_moduleMappings.erase(found);
        m_cbModuleMappings -= found->Size();

        // Add the new memory region.
        m_moduleMappings.insert(newRegion);
        m_cbModuleMappings += newRegion.Size();

        if (g_diagnostics) {
            newRegion.Trace("MODULE: REPLACE ");
        }
    }
}

//
// Returns the module base address for the IP or 0. Used by the thread unwind code.
//
uint64_t
CrashInfo::GetBaseAddressFromAddress(uint64_t address)
{
    MemoryRegion search(0, address, address, 0);
    const MemoryRegion* found = SearchMemoryRegions(m_moduleAddresses, search);
    if (found == nullptr) {
        return 0;
    }
    // The memory region Offset() is the base address of the module
    return found->Offset();
}

//
// Returns the module base address for the given module name or 0 if not found.
//
uint64_t
CrashInfo::GetBaseAddressFromName(const char* moduleName)
{
    for (const ModuleInfo* moduleInfo : m_moduleInfos)
    {
        std::string name = GetFileName(moduleInfo->ModuleName());
#ifdef __APPLE__
        // Module names are case insensitive on MacOS
        if (strcasecmp(name.c_str(), moduleName) == 0)
#else
        if (name.compare(moduleName) == 0)
#endif
        {
            return moduleInfo->BaseAddress();
        }
    }
    return 0;
}

//
// Return the module info for the base address
//
ModuleInfo*
CrashInfo::GetModuleInfoFromBaseAddress(uint64_t baseAddress)
{
    ModuleInfo search(baseAddress);
    const auto& found = m_moduleInfos.find(&search);
    if (found != m_moduleInfos.end())
    {
        return *found;
    }
    return nullptr;
}

//
// Adds module address range for IP lookup
//
void
CrashInfo::AddModuleAddressRange(uint64_t startAddress, uint64_t endAddress, uint64_t baseAddress)
{
    // Add module segment to base address lookup
    MemoryRegion region(0, startAddress, endAddress, baseAddress);
    m_moduleAddresses.insert(region);
}

//
// Adds module info (baseAddress, module name, etc)
//
void
CrashInfo::AddModuleInfo(bool isManaged, uint64_t baseAddress, IXCLRDataModule* pClrDataModule, const std::string& moduleName)
{
    ModuleInfo moduleInfo(baseAddress);
    const auto& found = m_moduleInfos.find(&moduleInfo);
    if (found == m_moduleInfos.end())
    {
        uint32_t timeStamp = 0;
        uint32_t imageSize = 0;
        bool isMainModule = false;
        GUID mvid;
        if (isManaged)
        {
            IMAGE_DOS_HEADER dosHeader;
            if (ReadMemory((void*)baseAddress, &dosHeader, sizeof(dosHeader)))
            {
                WORD magic;
                if (ReadMemory((void*)(baseAddress + dosHeader.e_lfanew + offsetof(IMAGE_NT_HEADERS, OptionalHeader.Magic)), &magic, sizeof(magic)))
                {
                    if (magic == IMAGE_NT_OPTIONAL_HDR32_MAGIC)
                    {
                        IMAGE_NT_HEADERS32 header;
                        if (ReadMemory((void*)(baseAddress + dosHeader.e_lfanew), &header, sizeof(header)))
                        {
                            imageSize = header.OptionalHeader.SizeOfImage;
                            timeStamp = header.FileHeader.TimeDateStamp;
                        }
                    }
                    else if (magic == IMAGE_NT_OPTIONAL_HDR64_MAGIC)
                    {
                        IMAGE_NT_HEADERS64 header;
                        if (ReadMemory((void*)(baseAddress + dosHeader.e_lfanew), &header, sizeof(header)))
                        {
                            imageSize = header.OptionalHeader.SizeOfImage;
                            timeStamp = header.FileHeader.TimeDateStamp;
                        }
                    }
                }
            }
            if (pClrDataModule != nullptr)
            {
                ULONG32 flags = 0;
                pClrDataModule->GetFlags(&flags);
                isMainModule = (flags & CLRDATA_MODULE_IS_MAIN_MODULE) != 0;
                pClrDataModule->GetVersionId(&mvid);
            }
            TRACE("MODULE: timestamp %08x size %08x %s %s%s\n", timeStamp, imageSize, FormatGuid(&mvid).c_str(), isMainModule ? "*" : "", moduleName.c_str());
        }
        ModuleInfo* moduleInfo = new ModuleInfo(isManaged, baseAddress, timeStamp, imageSize, &mvid, moduleName);
        if (isMainModule) {
            m_mainModule = moduleInfo;
        }
        m_moduleInfos.insert(moduleInfo);
    }
}

//
// ReadMemory from target and add to memory regions list
//
bool
CrashInfo::ReadMemory(void* address, void* buffer, size_t size)
{
    size_t read = 0;
    if (!ReadProcessMemory(address, buffer, size, &read))
    {
        return false;
    }
    assert(read == size);
    InsertMemoryRegion(reinterpret_cast<uint64_t>(address), read);
    return true;
}

//
// Add this memory chunk to the list of regions to be written to the core dump. Returns the number of pages actually added.
//
int
CrashInfo::InsertMemoryRegion(uint64_t address, size_t size)
{
    assert(size < UINT_MAX);

    // Round to page boundary
    uint64_t start = address & PAGE_MASK;
    assert(start > 0);

    // Round up to page boundary
    uint64_t end = ((address + size) + (PAGE_SIZE - 1)) & PAGE_MASK;
    assert(end > 0);

    return InsertMemoryRegion(MemoryRegion(GetMemoryRegionFlags(start), start, end));
}

//
// Add a memory region to the list. Returns the number of pages actually added.
//
int
CrashInfo::InsertMemoryRegion(const MemoryRegion& region)
{
    // Check if the new region overlaps with the previously added ones
    const auto& conflictingRegion = m_memoryRegions.find(region);
    const bool hasConflict = conflictingRegion != m_memoryRegions.end();
    if (hasConflict && conflictingRegion->Contains(region))
    {
        // The region is contained in the one we added before
        // Nothing to do
        return 0;
    }

    // Go page by page and split the region into valid sub-regions
    uint64_t pageStart = region.StartAddress();
    uint64_t numberPages = region.Size() / PAGE_SIZE;
    uint64_t subRegionStart, subRegionEnd;
    int pagesAdded = 0;
    subRegionStart = subRegionEnd = pageStart;
    for (size_t p = 0; p < numberPages; p++, pageStart += PAGE_SIZE)
    {
        MemoryRegion page(region.Flags(), pageStart, pageStart + PAGE_SIZE);

        // avoid searching for conflicts if we know we don't have one
        const bool pageHasConflicts = hasConflict && m_memoryRegions.find(page) != m_memoryRegions.end();
        // avoid validating the page if it conflicts: we won't add it in any case
        const bool pageIsValid = !pageHasConflicts && PageMappedToPhysicalMemory(pageStart) && PageCanBeRead(pageStart);

        if (pageIsValid)
        {
            subRegionEnd = page.EndAddress();
            pagesAdded++;
        }
        else
        {
            // the next page is not valid thus sub-region is complete
            if (subRegionStart != subRegionEnd)
            {
                m_memoryRegions.insert(MemoryRegion(region.Flags(), subRegionStart, subRegionEnd));
            }
            subRegionStart = subRegionEnd = page.EndAddress();
        }
    }
    // add the last sub-region if it's not empty
    if (subRegionStart != subRegionEnd)
    {
        m_memoryRegions.insert(MemoryRegion(region.Flags(), subRegionStart, subRegionEnd));
    }

    return pagesAdded;
}

//
// Check the page is really used by the application before adding it to the dump
// On some kernels reading a region from createdump results in committing this region in the parent application
// That leads to OOM in container environment and unnecesserally increses the size of the dump file
// However this is an optimization: if it fails we still try to add the page to the dump
//
bool
CrashInfo::PageMappedToPhysicalMemory(uint64_t start)
{
    #if !defined(__linux__)
        // this check has not been implemented yet for other unix systems
        return true;
    #else
        // https://www.kernel.org/doc/Documentation/vm/pagemap.txt
        if (m_fdPagemap == -1)
        {
            // Weren't able to open pagemap file, so don't run this check
            // Expected on kernels 4.0 and 4.1 as we need CAP_SYS_ADMIN to open /proc/pid/pagemap
            // On kernels after 4.2 we only need PTRACE_MODE_READ_FSCREDS as we are ok with zeroed PFNs
            return true;
        }

        uint64_t pagemapOffset = (start / PAGE_SIZE) * sizeof(uint64_t);
        uint64_t seekResult = lseek64(m_fdPagemap, (off64_t) pagemapOffset, SEEK_SET);
        if (seekResult != pagemapOffset)
        {
            int seekErrno = errno;
            TRACE("Seeking in pagemap file FAILED, addr: %" PRIA PRIx ", pagemap offset: %" PRIA PRIx ", ERRNO %d: %s\n", start, pagemapOffset, seekErrno, strerror(seekErrno));
            return true;
        }
        uint64_t value;
        size_t readResult = read(m_fdPagemap, (void*)&value, sizeof(value));
        if (readResult == (size_t) -1)
        {
            int readErrno = errno;
            TRACE("Reading of pagemap file FAILED, addr: %" PRIA PRIx ", pagemap offset: %" PRIA PRIx ", size: %zu, ERRNO %d: %s\n", start, pagemapOffset, sizeof(value), readErrno, strerror(readErrno));
            return true;
        }

        bool is_page_present = (value & ((uint64_t)1 << 63)) != 0;
        bool is_page_swapped = (value & ((uint64_t)1 << 62)) != 0;
        TRACE_VERBOSE("Pagemap value for %" PRIA PRIx ", pagemap offset %" PRIA PRIx " is %" PRIA PRIx " -> %s\n", start, pagemapOffset, value, is_page_present ? "in memory" : (is_page_swapped ? "in swap" : "NOT in memory"));
        return is_page_present || is_page_swapped;
    #endif
}

bool
CrashInfo::PageCanBeRead(uint64_t start)
{
    BYTE buffer[1];
    size_t read;
    return ReadProcessMemory((void*)start, buffer, 1, &read);
}

//
// Combine any adjacent memory regions into one
//
void
CrashInfo::CombineMemoryRegions()
{
    TRACE("CombineMemoryRegions: STARTED\n");
    assert(!m_memoryRegions.empty());
    std::set<MemoryRegion> memoryRegionsNew;

    // MEMORY_REGION_FLAG_SHARED and MEMORY_REGION_FLAG_PRIVATE are internal flags that
    // don't affect the core dump so ignore them when comparing the flags.
    uint32_t flags = m_memoryRegions.begin()->Flags() & MEMORY_REGION_FLAG_PERMISSIONS_MASK;
    uint64_t start = m_memoryRegions.begin()->StartAddress();
    uint64_t end = start;

    for (const MemoryRegion& region : m_memoryRegions)
    {
        // To combine a region it needs to be contiguous, same permissions and memory backed flag.
        if ((end == region.StartAddress()) &&
            (flags == (region.Flags() & MEMORY_REGION_FLAG_PERMISSIONS_MASK)))
        {
            end = region.EndAddress();
        }
        else
        {
            MemoryRegion memoryRegion(flags, start, end);
            assert(memoryRegionsNew.find(memoryRegion) == memoryRegionsNew.end());
            memoryRegionsNew.insert(memoryRegion);

            flags = region.Flags() & MEMORY_REGION_FLAG_PERMISSIONS_MASK;
            start = region.StartAddress();
            end = region.EndAddress();
        }
    }

    assert(start != end);
    MemoryRegion memoryRegion(flags, start, end);
    assert(memoryRegionsNew.find(memoryRegion) == memoryRegionsNew.end());
    memoryRegionsNew.insert(memoryRegion);

    m_memoryRegions = memoryRegionsNew;

    TRACE("CombineMemoryRegions: FINISHED\n");

    if (g_diagnosticsVerbose)
    {
        TRACE("Final Memory Regions:\n");
        for (const MemoryRegion& region : m_memoryRegions)
        {
            region.Trace();
        }
    }
}

//
// Searches for a memory region given an address.
//
const MemoryRegion*
CrashInfo::SearchMemoryRegions(const std::set<MemoryRegion>& regions, const MemoryRegion& search)
{
    std::set<MemoryRegion>::iterator found = regions.find(search);
    for (; found != regions.end(); found++)
    {
        if (search.StartAddress() >= found->StartAddress() && search.StartAddress() < found->EndAddress())
        {
            return &*found;
        }
    }
    return nullptr;
}

//
// Lookup a symbol in a module. The caller needs to call "free()" on symbol returned.
//
const char*
ModuleInfo::GetSymbolName(uint64_t address)
{
    LoadModule();

    if (m_localBaseAddress != 0)
    {
        uint64_t localAddress = m_localBaseAddress + (address - m_baseAddress);
        Dl_info info;
        if (dladdr((void*)localAddress, &info) != 0)
        {
            if (info.dli_sname != nullptr)
            {
                int status = -1;
                char *demangled = abi::__cxa_demangle(info.dli_sname, nullptr, 0, &status);
                return status == 0 ? demangled : strdup(info.dli_sname);
            }
        }
    }
    return nullptr;
}

//
// Returns just the file name portion of a file path
//
const std::string
GetFileName(const std::string& fileName)
{
    size_t last = fileName.rfind(DIRECTORY_SEPARATOR_STR_A);
    if (last != std::string::npos) {
        last++;
    }
    else {
        last = 0;
    }
    return fileName.substr(last);
}

//
// Returns just the directory portion of a path or empty if none
//
const std::string
GetDirectory(const std::string& fileName)
{
    size_t last = fileName.rfind(DIRECTORY_SEPARATOR_STR_A);
    if (last != std::string::npos) {
        last++;
    }
    else {
        last = 0;
    }
    return fileName.substr(0, last);
}

//
// Formats a std::string with printf syntax. The final formatted string is limited
// to MAX_LONGPATH (1024) chars. Returns an empty string on any error.
//
std::string
FormatString(const char* format, ...)
{
    ArrayHolder<char> buffer = new char[MAX_LONGPATH + 1];
    va_list args;
    va_start(args, format);
    int result = vsnprintf(buffer, MAX_LONGPATH, format, args);
    va_end(args);
    return result > 0 && result < MAX_LONGPATH ? std::string(buffer) : std::string();
}

//
// Converts a WCHAR into a std:string containing a UTF-8 encoded string.
//
std::string
ConvertString(const WCHAR* str)
{
    if (str == nullptr)
        return { };

    size_t cch = u16_strlen(str) + 1;
    int len = minipal_get_length_utf16_to_utf8((CHAR16_T*)str, cch, 0);
    if (len == 0)
        return { };

    ArrayHolder<char> buffer = new char[len + 1];
    minipal_convert_utf16_to_utf8((CHAR16_T*)str, cch, buffer, len + 1, 0);
    return std::string { buffer };
}

//
// Format a guid
//
std::string
FormatGuid(const GUID* guid)
{
    uint8_t* bytes = (uint8_t*)guid;
    return FormatString("%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
        bytes[3], bytes[2], bytes[1], bytes[0], bytes[5], bytes[4], bytes[7], bytes[6], bytes[8], bytes[9], bytes[10], bytes[11], bytes[12], bytes[13], bytes[14], bytes[15]);
}