Add crash dump callback

msipackage/package.wix.in

@@ -314,6 +314,14 @@
                     </RegistryKey>
                 </RegistryKey>
 
+                <!-- ICrashDumpCallback-->
+                <RegistryKey Root="HKCR" Key="Interface\{8C5A7B14-9D26-4FAE-AB31-7E5BC23F4801}">
+                    <RegistryValue Value="ICrashDumpCallback" Type="string" />
+                    <RegistryKey Key="ProxyStubClsid32">
+                        <RegistryValue Value="{4EA0C6DD-E9FF-48E7-994E-13A31D10DC60}" Type="string" />
+                    </RegistryKey>
+                </RegistryKey>
+
                 <!-- IProgressCallback-->
                 <RegistryKey Root="HKCR" Key="Interface\{5038842F-53DB-4F30-A6D0-A41B02C94AC1}">
                     <RegistryValue Value="IProgressCallback" Type="string" />

src/windows/WslcSDK/CMakeLists.txt

@@ -2,6 +2,7 @@ set(SOURCES
     IOCallback.cpp
     ProgressCallback.cpp
     TerminationCallback.cpp
+    CrashDumpCallback.cpp
     wslcsdk.cpp
     WslcsdkPrivate.cpp
 )
@@ -10,6 +11,7 @@ set(HEADERS
     IOCallback.h
     ProgressCallback.h
     TerminationCallback.h
+    CrashDumpCallback.h
     wslcsdk.h
     WslcsdkPrivate.h
 )

src/windows/WslcSDK/CrashDumpCallback.cpp

@@ -0,0 +1,52 @@
+/*++
+
+Copyright (c) Microsoft. All rights reserved.
+
+Module Name:
+
+    CrashDumpCallback.cpp
+
+Abstract:
+
+    Implementation of a type that implements ICrashDumpCallback.
+
+--*/
+#include "precomp.h"
+#include "CrashDumpCallback.h"
+
+CrashDumpCallback::CrashDumpCallback(WslcSessionCrashDumpCallback callback, PVOID context) :
+    m_callback(callback), m_context(context)
+{
+}
+
+HRESULT STDMETHODCALLTYPE CrashDumpCallback::OnCrashDump(
+    _In_ LPCWSTR DumpPath, _In_opt_ LPCSTR ProcessName, _In_ ULONGLONG Pid, _In_ ULONG Signal, _In_ ULONGLONG Timestamp)
+try
+{
+    if (m_callback)
+    {
+        WslcSessionCrashDumpInfo info{};
+        info.dumpPath = DumpPath;
+        info.processName = ProcessName ? ProcessName : "";
+        info.pid = Pid;
+        info.signal = Signal;
+        info.timestamp = Timestamp;
+
+        m_callback(&info, m_context);
+    }
+
+    return S_OK;
+}
+CATCH_RETURN();
+
+winrt::com_ptr<CrashDumpCallback> CrashDumpCallback::CreateIf(const WslcSessionOptionsInternal* options)
+{
+    if (options->crashDumpCallback)
+    {
+        return winrt::make_self<CrashDumpCallback>(options->crashDumpCallback, options->crashDumpCallbackContext);
+    }
+    else
+    {
+        return nullptr;
+    }
+}

src/windows/WslcSDK/CrashDumpCallback.h

@@ -0,0 +1,34 @@
+/*++
+
+Copyright (c) Microsoft. All rights reserved.
+
+Module Name:
+
+    CrashDumpCallback.h
+
+Abstract:
+
+    Header for a type that implements ICrashDumpCallback. Bridges the COM
+    ICrashDumpCallback interface back to the C-style SDK callback registered
+    via WslcSetSessionSettingsCrashDumpCallback.
+
+--*/
+#pragma once
+#include "wslc.h"
+#include "wslcsdkprivate.h"
+#include <winrt/base.h>
+
+struct CrashDumpCallback : public winrt::implements<CrashDumpCallback, ICrashDumpCallback>
+{
+    CrashDumpCallback(WslcSessionCrashDumpCallback callback, PVOID context);
+
+    // ICrashDumpCallback
+    HRESULT STDMETHODCALLTYPE OnCrashDump(_In_ LPCWSTR DumpPath, _In_opt_ LPCSTR ProcessName, _In_ ULONGLONG Pid, _In_ ULONG Signal, _In_ ULONGLONG Timestamp) override;
+
+    // Creates a CrashDumpCallback if the options provides a callback.
+    static winrt::com_ptr<CrashDumpCallback> CreateIf(const WslcSessionOptionsInternal* options);
+
+private:
+    WslcSessionCrashDumpCallback m_callback = nullptr;
+    PVOID m_context = nullptr;
+};

src/windows/WslcSDK/WslcsdkPrivate.h

@@ -35,6 +35,9 @@ typedef struct WslcSessionOptionsInternal
     WslcSessionFeatureFlags featureFlags;
     WslcSessionTerminationCallback terminationCallback;
     PVOID terminationCallbackContext;
+
+    WslcSessionCrashDumpCallback crashDumpCallback;
+    PVOID crashDumpCallbackContext;
 } WslcSessionOptionsInternal;
 
 static_assert(sizeof(WslcSessionOptionsInternal) == WSLC_SESSION_OPTIONS_SIZE, "WSLC_SESSION_OPTIONS_INTERNAL size mismatch");
@@ -108,6 +111,7 @@ struct WslcSessionImpl
 {
     wil::com_ptr<IWSLCSession> session;
     wil::com_ptr<ITerminationCallback> terminationCallback;
+    wil::com_ptr<ICrashDumpCallback> crashDumpCallback;
 };
 
 WslcSessionImpl* GetInternalType(WslcSession handle);

src/windows/WslcSDK/wslcsdk.cpp

@@ -18,6 +18,7 @@ Module Name:
 #include "Defaults.h"
 #include "ProgressCallback.h"
 #include "TerminationCallback.h"
+#include "CrashDumpCallback.h"
 #include "Localization.h"
 #include "WslInstall.h"
 #include "wslutil.h"
@@ -440,6 +441,12 @@ try
         result->terminationCallback.attach(terminationCallback.as<ITerminationCallback>().detach());
         runtimeSettings.TerminationCallback = terminationCallback.get();
     }
+    auto crashDumpCallback = CrashDumpCallback::CreateIf(internalType);
+    if (crashDumpCallback)
+    {
+        result->crashDumpCallback.attach(crashDumpCallback.as<ICrashDumpCallback>().detach());
+        runtimeSettings.CrashDumpCallback = crashDumpCallback.get();
+    }
     runtimeSettings.FeatureFlags = ConvertFlags(internalType->featureFlags);
     WI_SetFlag(runtimeSettings.FeatureFlags, WslcFeatureFlagsVirtioFs);
     WI_SetFlag(runtimeSettings.FeatureFlags, WslcFeatureFlagsDnsTunneling);
@@ -599,6 +606,20 @@ try
 }
 CATCH_RETURN();
 
+STDAPI WslcSetSessionSettingsCrashDumpCallback(
+    _In_ WslcSessionSettings* sessionSettings, _In_opt_ WslcSessionCrashDumpCallback crashDumpCallback, _In_opt_ PVOID crashDumpContext)
+try
+{
+    auto internalType = CheckAndGetInternalType(sessionSettings);
+    RETURN_HR_IF(E_INVALIDARG, crashDumpCallback == nullptr && crashDumpContext != nullptr);
+
+    internalType->crashDumpCallback = crashDumpCallback;
+    internalType->crashDumpCallbackContext = crashDumpContext;
+
+    return S_OK;
+}
+CATCH_RETURN();
+
 STDAPI WslcReleaseSession(_In_ WslcSession session)
 try
 {
@@ -608,6 +629,7 @@ try
     // the termination callback ends up being invoked by session destruction.
     internalType->session.reset();
     internalType->terminationCallback.reset();
+    internalType->crashDumpCallback.reset();
 
     return S_OK;
 }

src/windows/WslcSDK/wslcsdk.def

@@ -21,6 +21,7 @@ WslcSetSessionSettingsCpuCount
 WslcSetSessionSettingsMemory
 WslcSetSessionSettingsTimeout
 WslcSetSessionSettingsVhd
+WslcSetSessionSettingsCrashDumpCallback
 
 WslcTerminateSession
 WslcSessionAuthenticate

src/windows/WslcSDK/wslcsdk.h

@@ -42,7 +42,7 @@ EXTERN_C_START
 #define WSLC_E_REGISTRY_BLOCKED_BY_POLICY MAKE_HRESULT(SEVERITY_ERROR, FACILITY_ITF, WSLC_E_BASE + 13) /* 0x8004060D */
 
 // Session values
-#define WSLC_SESSION_OPTIONS_SIZE 88
+#define WSLC_SESSION_OPTIONS_SIZE 104
 #define WSLC_SESSION_OPTIONS_ALIGNMENT 8
 
 typedef struct WslcSessionSettings
@@ -125,6 +125,17 @@ typedef enum WslcSessionTerminationReason
 
 typedef __callback void(CALLBACK* WslcSessionTerminationCallback)(_In_ WslcSessionTerminationReason reason, _In_opt_ PVOID context);
 
+typedef struct WslcSessionCrashDumpInfo
+{
+    _Field_z_ PCWSTR dumpPath;
+    _Field_z_ PCSTR processName;
+    uint64_t pid;
+    uint32_t signal;
+    uint64_t timestamp;
+} WslcSessionCrashDumpInfo;
+
+typedef __callback void(CALLBACK* WslcSessionCrashDumpCallback)(_In_ const WslcSessionCrashDumpInfo* info, _In_opt_ PVOID context);
+
 STDAPI WslcInitSessionSettings(_In_ PCWSTR name, _In_ PCWSTR storagePath, _Out_ WslcSessionSettings* sessionSettings);
 
 STDAPI WslcCreateSession(_In_ WslcSessionSettings* sessionSettings, _Out_ WslcSession* session, _Outptr_opt_result_z_ PWSTR* errorMessage);
@@ -142,6 +153,9 @@ STDAPI WslcSetSessionSettingsFeatureFlags(_In_ WslcSessionSettings* sessionSetti
 STDAPI WslcSetSessionSettingsTerminationCallback(
     _In_ WslcSessionSettings* sessionSettings, _In_opt_ WslcSessionTerminationCallback terminationCallback, _In_opt_ PVOID terminationContext);
 
+STDAPI WslcSetSessionSettingsCrashDumpCallback(
+    _In_ WslcSessionSettings* sessionSettings, _In_opt_ WslcSessionCrashDumpCallback crashDumpCallback, _In_opt_ PVOID crashDumpContext);
+
 STDAPI WslcTerminateSession(_In_ WslcSession session);
 STDAPI WslcReleaseSession(_In_ WslcSession session);
 

src/windows/service/exe/WSLCSessionManager.cpp

@@ -427,6 +427,7 @@ WSLCSessionInitSettings WSLCSessionManagerImpl::CreateSessionSettings(
     sessionSettings.RootVhdTypeOverride = Settings->RootVhdTypeOverride;
     sessionSettings.StorageFlags = Settings->StorageFlags;
     sessionSettings.SwapSizeMb = Settings->MemoryMb;
+    sessionSettings.CrashDumpCallback = Settings->CrashDumpCallback;
     return sessionSettings;
 }
 

src/windows/service/inc/wslc.idl

@@ -107,6 +107,21 @@ interface ITerminationCallback : IUnknown
     HRESULT OnTermination(WSLCVirtualMachineTerminationReason Reason, LPCWSTR Details);
 };
 
+[
+    uuid(8C5A7B14-9D26-4FAE-AB31-7E5BC23F4801),
+    pointer_default(unique),
+    object
+]
+interface ICrashDumpCallback : IUnknown
+{
+    HRESULT OnCrashDump(
+        [in, string] LPCWSTR DumpPath,
+        [in, unique, string] LPCSTR ProcessName,
+        [in] ULONGLONG Pid,
+        [in] ULONG Signal,
+        [in] ULONGLONG Timestamp);
+};
+
 [
     uuid(5038842F-53DB-4F30-A6D0-A41B02C94AC1),
     pointer_default(unique),
@@ -526,6 +541,7 @@ typedef struct _WSLCSessionSettings {
     // Below options are used for debugging purposes only.
     [unique] LPCWSTR RootVhdOverride;
     [unique] LPCSTR RootVhdTypeOverride;
+    [unique] ICrashDumpCallback* CrashDumpCallback;
 } WSLCSessionSettings;
 
 typedef enum _WSLCLogsFlags
@@ -716,6 +732,7 @@ typedef struct _WSLCSessionInitSettings
     WSLCNetworkingMode NetworkingMode;
     WSLCFeatureFlags FeatureFlags;
     [unique] LPCSTR RootVhdTypeOverride;
+    [unique] ICrashDumpCallback* CrashDumpCallback;
 } WSLCSessionInitSettings;
 
 [

src/windows/wslcsession/WSLCVirtualMachine.cpp

@@ -254,6 +254,7 @@ WSLCVirtualMachine::WSLCVirtualMachine(_In_ IWSLCVirtualMachine* Vm, _In_ const
     m_networkingMode(Settings->NetworkingMode),
     m_bootTimeoutMs(Settings->BootTimeoutMs),
     m_rootVhdType(Settings->RootVhdTypeOverride ? Settings->RootVhdTypeOverride : "ext4"),
+    m_crashDumpCallback(Settings->CrashDumpCallback),
     m_sessionTerminatingEvent(SessionTerminatingEvent)
 {
     // N.B. The constructor should not run any operation that could throw, so the destructor runs even if the VM fails to boot.
@@ -1247,6 +1248,8 @@ void WSLCVirtualMachine::CollectCrashDumps(wil::unique_socket&& listenSocket)
     // No impersonation needed - the session process already runs as the user.
     wslutil::SetThreadDescription(L"CrashDumpCollection");
 
+    const auto coInit = wil::CoInitializeEx(COINIT_MULTITHREADED);
+
     const auto crashDumpFolder = filesystem::GetTempFolderPath(GetCurrentProcessToken()) / L"wslc-crashes";
 
     while (!m_vmTerminatingEvent.is_signaled())
@@ -1273,10 +1276,14 @@ void WSLCVirtualMachine::CollectCrashDumps(wil::unique_socket&& listenSocket)
             const auto bufferSize = responseSpan.size_bytes() - offsetof(LX_PROCESS_CRASH, Buffer);
             const std::string process(message.Buffer, strnlen(message.Buffer, bufferSize));
 
+            const auto crashPid = message.Pid;
+            const auto crashSignal = message.Signal;
+            const auto crashTimestamp = message.Timestamp;
+
             constexpr auto dumpExtension = ".dmp";
             constexpr auto dumpPrefix = "wsl-crash";
 
-            auto filename = std::format("{}-{}-{}-{}-{}{}", dumpPrefix, message.Timestamp, message.Pid, process, message.Signal, dumpExtension);
+            auto filename = std::format("{}-{}-{}-{}-{}{}", dumpPrefix, crashTimestamp, crashPid, process, crashSignal, dumpExtension);
 
             std::replace_if(
                 filename.begin(),
@@ -1289,8 +1296,8 @@ void WSLCVirtualMachine::CollectCrashDumps(wil::unique_socket&& listenSocket)
             WSL_LOG(
                 "WSLCLinuxCrash",
                 TraceLoggingValue(fullPath.c_str(), "FullPath"),
-                TraceLoggingValue(message.Pid, "Pid"),
-                TraceLoggingValue(message.Signal, "Signal"),
+                TraceLoggingValue(crashPid, "Pid"),
+                TraceLoggingValue(crashSignal, "Signal"),
                 TraceLoggingValue(process.c_str(), "process"));
 
             filesystem::EnsureDirectory(crashDumpFolder.c_str());
@@ -1314,6 +1321,13 @@ void WSLCVirtualMachine::CollectCrashDumps(wil::unique_socket&& listenSocket)
 
             transaction.SendResultMessage<std::int32_t>(0);
             relay::InterruptableRelay(reinterpret_cast<HANDLE>(channel.Socket()), file.get(), nullptr);
+
+            // Invoke the crash dump callback (if any) now that the dump file has been fully
+            // written. Failures in the callback are logged but do not interrupt crash collection.
+            if (m_crashDumpCallback)
+            {
+                LOG_IF_FAILED(m_crashDumpCallback->OnCrashDump(fullPath.c_str(), process.c_str(), crashPid, crashSignal, crashTimestamp));
+            }
         }
         CATCH_LOG()
     }

src/windows/wslcsession/WSLCVirtualMachine.h

@@ -219,6 +219,9 @@ class WSLCVirtualMachine
 
     std::string m_rootVhdType;
 
+    // Optional callback invoked after a crash dump is successfully written.
+    wil::com_ptr<ICrashDumpCallback> m_crashDumpCallback;
+
     std::thread m_processExitThread;
     std::thread m_crashDumpThread;