[LLDB] [Windows] Fix Windows-specific race condition in LLDB for session lifetime

This can e.g. happen if the debugged executable exits before the initial
stop, e.g. if it fails to load dependent DLLs.

Add a virtual destructor to ProcessDebugger and let it clean up the
session, and make ProcessWindows::OnExitProcess call
ProcessDebugger::OnExitProcess for shared parts.

Fix suggestion by Adrian McCarthy.

Differential Revision: https://reviews.llvm.org/D69503

diff --git a/lldb/source/Plugins/Process/Windows/Common/ProcessDebugger.cpp b/lldb/source/Plugins/Process/Windows/Common/ProcessDebugger.cpp
index 6ee882f..cd78051 100644 (file)
--- a/lldb/source/Plugins/Process/Windows/Common/ProcessDebugger.cpp
+++ b/lldb/source/Plugins/Process/Windows/Common/ProcessDebugger.cpp
@@ -63,6 +63,8 @@ static bool IsPageExecutable(uint32_t protect) {
 
 namespace lldb_private {
 
+ProcessDebugger::~ProcessDebugger() {}
+
 lldb::pid_t ProcessDebugger::GetDebuggedProcessId() const {
   if (m_session_data)
     return m_session_data->m_debugger->GetProcess().GetProcessId();

diff --git a/lldb/source/Plugins/Process/Windows/Common/ProcessDebugger.h b/lldb/source/Plugins/Process/Windows/Common/ProcessDebugger.h
index b4d053f..a4db764 100644 (file)
--- a/lldb/source/Plugins/Process/Windows/Common/ProcessDebugger.h
+++ b/lldb/source/Plugins/Process/Windows/Common/ProcessDebugger.h
@@ -48,6 +48,8 @@ public:
 class ProcessDebugger {
 
 public:
+  virtual ~ProcessDebugger();
+
   virtual void OnExitProcess(uint32_t exit_code);
   virtual void OnDebuggerConnected(lldb::addr_t image_base);
   virtual ExceptionResult OnDebugException(bool first_chance,

diff --git a/lldb/source/Plugins/Process/Windows/Common/ProcessWindows.cpp b/lldb/source/Plugins/Process/Windows/Common/ProcessWindows.cpp
index c4b7a6d..d4e60ec 100644 (file)
--- a/lldb/source/Plugins/Process/Windows/Common/ProcessWindows.cpp
+++ b/lldb/source/Plugins/Process/Windows/Common/ProcessWindows.cpp
@@ -625,16 +625,7 @@ void ProcessWindows::OnExitProcess(uint32_t exit_code) {
   SetProcessExitStatus(GetID(), true, 0, exit_code);
   SetPrivateState(eStateExited);
 
-  // If the process exits before any initial stop then notify the debugger
-  // of the error otherwise WaitForDebuggerConnection() will be blocked.
-  // An example of this issue is when a process fails to load a dependent DLL.
-  if (m_session_data && !m_session_data->m_initial_stop_received) {
-    Status error(exit_code, eErrorTypeWin32);
-    OnDebuggerError(error, 0);
-  }
-
-  // Reset the session.
-  m_session_data.reset();
+  ProcessDebugger::OnExitProcess(exit_code);
 }
 
 void ProcessWindows::OnDebuggerConnected(lldb::addr_t image_base) {

diff --git a/lldb/test/Shell/Process/Windows/launch_failure.yaml b/lldb/test/Shell/Process/Windows/launch_failure.yaml
new file mode 100644 (file)
index 0000000..be723ef
--- /dev/null
+++ b/lldb/test/Shell/Process/Windows/launch_failure.yaml
@@ -0,0 +1,90 @@
+## Test that we don't crash when the process fails to launch before reaching
+## the initial stop. This test exe has a dependency on NonExistent.dll.
+
+# REQUIRES: system-windows
+# REQUIRES: native && target-x86_64
+
+# RUN: yaml2obj %s > %t.exe
+# RUN: %lldb %t.exe -o run 2>&1 | FileCheck %s
+
+# CHECK: error: process launch failed: unknown error
+
+--- !COFF
+OptionalHeader:
+  AddressOfEntryPoint: 4096
+  ImageBase:       1073741824
+  SectionAlignment: 4096
+  FileAlignment:   512
+  MajorOperatingSystemVersion: 6
+  MinorOperatingSystemVersion: 0
+  MajorImageVersion: 0
+  MinorImageVersion: 0
+  MajorSubsystemVersion: 6
+  MinorSubsystemVersion: 0
+  Subsystem:       IMAGE_SUBSYSTEM_WINDOWS_CUI
+  DLLCharacteristics: [ IMAGE_DLL_CHARACTERISTICS_HIGH_ENTROPY_VA, IMAGE_DLL_CHARACTERISTICS_DYNAMIC_BASE, IMAGE_DLL_CHARACTERISTICS_NX_COMPAT, IMAGE_DLL_CHARACTERISTICS_TERMINAL_SERVER_AWARE ]
+  SizeOfStackReserve: 1048576
+  SizeOfStackCommit: 4096
+  SizeOfHeapReserve: 1048576
+  SizeOfHeapCommit: 4096
+  ExportTable:
+    RelativeVirtualAddress: 0
+    Size:            0
+  ImportTable:
+    RelativeVirtualAddress: 8192
+    Size:            40
+  ResourceTable:
+    RelativeVirtualAddress: 0
+    Size:            0
+  ExceptionTable:
+    RelativeVirtualAddress: 0
+    Size:            0
+  CertificateTable:
+    RelativeVirtualAddress: 0
+    Size:            0
+  BaseRelocationTable:
+    RelativeVirtualAddress: 0
+    Size:            0
+  Debug:
+    RelativeVirtualAddress: 0
+    Size:            0
+  Architecture:
+    RelativeVirtualAddress: 0
+    Size:            0
+  GlobalPtr:
+    RelativeVirtualAddress: 0
+    Size:            0
+  TlsTable:
+    RelativeVirtualAddress: 0
+    Size:            0
+  LoadConfigTable:
+    RelativeVirtualAddress: 0
+    Size:            0
+  BoundImport:
+    RelativeVirtualAddress: 0
+    Size:            0
+  IAT:
+    RelativeVirtualAddress: 8248
+    Size:            16
+  DelayImportDescriptor:
+    RelativeVirtualAddress: 0
+    Size:            0
+  ClrRuntimeHeader:
+    RelativeVirtualAddress: 0
+    Size:            0
+header:
+  Machine:         IMAGE_FILE_MACHINE_AMD64
+  Characteristics: [ IMAGE_FILE_EXECUTABLE_IMAGE, IMAGE_FILE_LARGE_ADDRESS_AWARE ]
+sections:
+  - Name:            .text
+    Characteristics: [ IMAGE_SCN_CNT_CODE, IMAGE_SCN_MEM_EXECUTE, IMAGE_SCN_MEM_READ ]
+    VirtualAddress:  4096
+    VirtualSize:     7
+    SectionData:     48FF2531100000
+  - Name:            .rdata
+    Characteristics: [ IMAGE_SCN_CNT_INITIALIZED_DATA, IMAGE_SCN_MEM_READ ]
+    VirtualAddress:  8192
+    VirtualSize:     96
+    SectionData:     282000000000000000000000502000003820000000000000000000000000000000000000000000004820000000000000000000000000000048200000000000000000000000000000000066756E6300004E6F6E4578697374656E742E646C6C00
+symbols:         []
+...